Biomedical subjects

Charles V Pollack

Publications and source records attributed to Charles V Pollack.

At least 19 recordsLinked to original sources

PubMed2006

The role of cardiac risk factor burden in diagnosing acute coronary syndromes in the emergency department setting.

STUDY OBJECTIVE: We seek to determine whether cardiac risk factor burden (defined as the number of conventional cardiac risk factors present) is useful for the diagnosis of acute coronary syndromes in the emergency department (ED) setting. METHODS: This was a post hoc analysis of the Internet Tracking Registry of Acute Coronary Syndromes (i*trACS) registry, which had 17,713 ED visits for suspected acute coronary syndromes. First visit for US patients who were not cocaine or amphetamine users, who did not leave against medical advice, and for whom ECG and demographic data were complete were included. Acute coronary syndrome was defined by 30-day revascularization, diagnostic-related group codes, or death within 30 days, with positive cardiac biomarkers at index hospitalization. Cardiac risk factors were diabetes, hypertension, smoking, hypercholesterolemia, and family history of coronary artery disease. Cardiac risk factor burden was defined as the number of risk factors present. Because multiple logistic regression analysis revealed that age modified the relationship between cardiac risk factor burden and acute coronary syndromes, a stratified analysis was performed for 3 age categories: younger than 40, 40 to 65, and older than 65 years. Positive likelihood ratios and negative likelihood ratios with their 95% confidence intervals (CIs) were calculated for each total risk factor cutoff. RESULTS: Of 10,806 eligible patients, 871 (8.1%) had acute coronary syndromes. In patients younger than 40 years, having no risk factors had a negative likelihood ratio of 0.17 (95% CI 0.04 to 0.66), and having 4 or more risk factors had a positive likelihood ratio of 7.39 (95% CI 3.09 to 17.67). In patients between 40 and 65 years of age, having no risk factors had a negative likelihood ratio of 0.53 (95% CI 0.40 to 0.71), and having 4 or more risk factors had a positive likelihood ratio of 2.13 (95% CI 1.66 to 2.73). In patients older than 65 years, having no risk factors had a negative likelihood ratio of 0.96 (95% CI 0.74 to 1.23), and having 4 or more risk factors had a positive likelihood ratio of 1.09 (95% CI 0.64 to 1.62). CONCLUSION: Cardiac risk factor burden has limited clinical value in diagnosing acute coronary syndromes in the ED setting, especially in patients older than 40 years.

Adult↗

PubMed2006

Recent trends in the care of patients with non-ST-segment elevation acute coronary syndromes: insights from the CRUSADE initiative.

BACKGROUND: The extent to which national health quality improvement initiatives have altered reported treatment gaps among patients with non-ST-segment elevation acute coronary syndromes (NSTE ACS) is unknown. We sought to determine recent trends in adherence to guideline-based therapies for NSTE ACS. METHODS: We evaluated the treatment of patients with high-risk (positive cardiac markers and/or ischemic ST-segment changes) NSTE ACS enrolled in the Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes With Early Implementation of the ACC/AHA (American College of Cardiology/American Heart Association) Guidelines (CRUSADE) Quality Improvement Initiative from 2002 through 2004 (a total of 113 595 patients over 11 calendar quarters). We analyzed adherence to guideline-recommended therapies, including medications used in the acute care period (<24 hours after presentation), invasive procedures, in-hospital outcomes, and discharge therapies and interventions. RESULTS: The use of each class I guideline recommendation, as well as overall adherence to the guidelines, improved significantly (P<.001) during the study period. In the acute care setting, the use of antiplatelet agents increased by 5% and beta-blockers by 12%; at hospital discharge, the use of antiplatelet agents increased by 3% and beta-blockers by 8%. Heparin use in the acute care period increased by 6%, largely owing to a 9% increase in the use of low-molecular-weight heparin. Use of glycoprotein IIb/IIIa inhibitors in the acute care period also increased by more than 13%. At discharge, clopidogrel use increased by 22%, lipid-lowering agents by 11%, and angiotensin-converting enzyme inhibitors by 5%. While adherence improved, many patients still failed to receive 100% indicated treatments at the end of the study period. CONCLUSIONS: During the 4 years since the initial release of the ACC/AHA guidelines for NSTE ACS, adherence to class I recommendations has significantly improved among hospitals participating in CRUSADE. Still, further improvements are needed for optimal implementation of the these guidelines.

Adrenergic beta-Antagonists↗

PubMed2006

The Internet Tracking Registry of Acute Coronary Syndromes (i*trACS): a multicenter registry of patients with suspicion of acute coronary syndromes reported using the standardized reporting guidelines for emergency department chest pain studies.

STUDY OBJECTIVE: Observational studies of well-described patient populations presenting to emergency departments (EDs) with suspicion of acute coronary syndrome are necessary to understand the relationships between patients' signs and symptoms, cardiac risk profile, test results, practice patterns, and outcomes. We describe the methods for data collection and the ED population enrolled in a multicenter registry of patients with chest pain. METHODS: Patients older than 18 years, presenting to one of 8 EDs in the United States or 1 ED in Singapore, and with possible acute coronary syndrome were enrolled in the Internet Tracking Registry of Acute Coronary Syndromes between June 1999 and August 2001. Prospective data, including presenting signs and symptoms, ECG findings, and the ED physician's initial impression of risk, were systematically collected. Medical record review or daily follow-up was used to obtain cardiac biomarker results, invasive and noninvasive testing, treatments, procedures, and inhospital outcomes. Thirty-day outcomes were determined by telephone follow-up and medical record review. RESULTS: The registry includes 15,608 patients, with 17,713 visits. Chest pain was the chief complaint in 71% of visits. The ECG was diagnostic of ischemia or infarction in 10.1% and positive cardiac biomarkers were observed in 10% of visits. Forty-three percent of patients were sent home directly from the ED. Of admitted patients, 5% died by 30 days, and 3% had documented coronary artery disease or had undergone percutaneous coronary intervention or coronary artery bypass grafting within 30 days. For patients discharged directly from the ED, 0.4% died or had a documented myocardial infarction within 30 days. Coronary artery bypass graft surgery, percutaneous coronary intervention, or a diagnosis of coronary artery disease was found in 0.5% of discharged patients. CONCLUSION: A unique description of undifferentiated ED chest pain patients with suspected acute coronary syndrome is provided. The data set can be used to generate and explore hypotheses to improve understanding of the complex relationships between presentation, treatment, testing, intervention and outcomes.

Biomarkers↗

PubMed2006

Prognostic value of symptoms during a normal or nonspecific electrocardiogram in emergency department patients with potential acute coronary syndrome.

OBJECTIVES: Emergency department (ED) patients with symptoms concerning for acute coronary syndrome (ACS) and a normal electrocardiogram (ECG) are at risk for adverse cardiovascular events. The authors hypothesized that patients with a normal or nonspecific ECG during symptoms have a lower risk for ACS than do those who are asymptomatic. METHODS: This was a prospective cohort study of ED patients with potential ACS. Outcomes were acute myocardial infarction (AMI), ACS, and 30-day cardiovascular events (death, AMI, revascularization). Fisher's exact test, t-tests, and logistic regression were used for data analysis. RESULTS: Of 2,593 patient visits, 2,007 patients had normal or nonspecific ECG findings. There were 1,196 who had symptoms during ECG, whereas 811 did not. Patients with symptoms at ECG acquisition were younger (49.9 vs. 55.2 years; p < 0.001) and were more likely to be black (70% vs. 64%; p = 0.002), female (63% vs. 58%; p = 0.03), and to have used cocaine (5% vs. 2%; p = 0.004). They were less likely to have hypertension (49% vs. 58%; p < 0.001), and diabetes (22% vs. 17%; p = 0.002). Patients with and without symptoms were equally likely to have AMI (both 2.8%; p > 0.99), ACS (10.1% vs. 11.5%; p = 0.34), and 30-day adverse outcomes (both 5.3%; p > 0.99). After adjustment for baseline cardiovascular-risk factors, odds ratios for patients with symptoms at the time of ECG acquisition were not significantly different for any of the outcomes: AMI (1.1; 95% confidence interval [CI] = 0.6 to 1.9); ACS (1.1; 95% CI = 0.8 to 1.4); or 30-day events (1.2; 95% CI = 0.8 to 1.9). CONCLUSIONS: Patients who are symptomatic during acquisition of a normal or nonspecific ECG have rates of adverse cardiovascular events similar to those of patients without symptoms. Clinicians should not rely on the absence of ECG abnormalities during symptoms to help exclude ACS.

Cohort Studies↗

PubMed2006

A subgroup analysis of the impact of prerandomization antithrombin therapy on outcomes in the SYNERGY trial: enoxaparin versus unfractionated heparin in non-ST-segment elevation acute coronary syndromes.

OBJECTIVES: The purpose of this study was to compare the effect of receiving pretreatment with antithrombin before randomization as well as overall efficacy and safety of enoxaparin versus unfractionated heparin (UFH) in the SYNERGY (Superior Yield of the New Strategy of Enoxaparin, Revascularization, and Glycoprotein IIb/IIIa Inhibitors) trial. BACKGROUND: The SYNERGY trial results demonstrated noninferiority in outcomes with enoxaparin compared with UFH. Randomized treatment was independent of prerandomization treatment. METHODS: Analyses were first performed on the 4 prerandomization subgroups: patients who received no antithrombin therapy and those who were treated with enoxaparin or UFH or both. Then, we focused on the subgroup of patients who received no pretreatment or were pretreated with and randomized to the same drug. Of the 9,978 patients, 2,440 did not receive prerandomization therapy and 6,138 received consistent therapy through randomization. The primary end point was the composite of death and nonfatal myocardial infarction (MI) at 30 days. RESULTS: After adjustment for differences among the subgroups, no significant difference in the association between the 4 pretreatment groups and death or MI remained (p = 0.171). The randomized treatment effect on 30-day death or MI tended to vary with pretreatment (p = 0.055 for interaction test after adjustment). Patients who received consistent therapy with enoxaparin had significantly less death or MI than patients randomized to UFH (adjusted p = 0.041) with a trend toward increased bleeding. CONCLUSIONS: Treatment with antithrombin therapy before randomization had potential impact on comparison of study drug effects. After adjustment for differences in baseline characteristics between subgroups, consistent therapy with enoxaparin might be superior to UFH in reducing death or nonfatal MI, with a modest excess in bleeding.

Aged↗

PubMed2006

Discordant cardiac biomarkers: frequency and outcomes in emergency department patients with chest pain.

STUDY OBJECTIVE: We evaluate associations between pairs of discordant cardiac biomarkers (positive MB band of creatine kinase [CKMB] with negative creatine kinase, positive CKMB with negative cardiac troponin, and positive troponin with negative CKMB) and the presence of acute coronary syndromes in emergency department (ED) chest pain patients. METHODS: This was a secondary analysis of a prospective registry. Data were obtained from the multicenter Internet Tracking Registry of Acute Coronary Syndromes, which included 17,713 ED visits for possible acute coronary syndrome between June 1999 and August 2001. First visits and first ED cardiac biomarker results from the 9 sites, 8 in the United States and 1 in Singapore, were included. Subjects were excluded for incomplete information or an initial ECG consistent with ST-segment elevation myocardial infarction. Acute coronary syndrome was defined by diagnosis-related group code indicating myocardial infarction, positive invasive or noninvasive diagnostic testing, revascularization, or death during hospitalization or within 30 days. RESULTS: Of 8,769 eligible patients, 1,614 (18.4%) had acute coronary syndrome. The CKMB and cardiac troponin results were discordant in 7% of patients (CKMB+/cardiac troponin-, 4.9%, CKMB-/cardiac troponin+ 2.1%), whereas increased CKMB with normal creatine kinase levels occurred in 239 (3.1%) patients. The unadjusted odds ratios with 95% confidence intervals for acute coronary syndrome in patients with and without discordant markers were: CKMB+/CK- 5.7 (4.4-7.4), CKMB+/CK+ 4.4 (3.6-5.2), CKMB-/cTn+ 4.8 (3.4-6.8), CKMB+/cTn- 2.2 (1.7-2.8), CKMB+/cTn+ 26.6 (18.0-39.3). For the group with cardiac troponin, the reference category was negative troponin and negative CKMB; for the group with creatine kinase, the reference category was negative CKMB but either a positive or negative creatine kinase. CONCLUSION: Among the spectrum of ED patients with chest pain, an increased CKMB level with a normal creatine kinase level identifies patients at increased risk for acute coronary syndrome. Similarly, an increased troponin level regardless of CKMB level and an increased CKMB level regardless of troponin level identify patients at higher risk for acute coronary syndrome than those with uniformly normal cardiac biomarker levels. Our data suggest that discordant cardiac biomarkers may identify patients at increased risk for acute coronary syndrome.

Biomarkers↗

PubMed2006

Challenges in predicting the need for coronary artery bypass grafting at presentation in patients with non-ST-segment elevation acute coronary syndromes.

In the case of non-ST-segment elevation acute coronary syndromes (NSTE-ACSs), the acute use of certain antiplatelet agents is complicated by concerns about perioperative bleeding risks in patients requiring coronary artery bypass grafting (CABG) during the index hospitalization. As a result, clinicians often withhold potentially useful agents, such as clopidogrel, before determining patients' coronary anatomy. An accurate predictive model could allow for a better balance of this safety concern with the demonstrated benefits of agents such as clopidogrel. To create an accurate decision-making tool that would assess, at hospital presentation, the need for CABG in patients with NSTE-ACSs, we studied 61,974 high-risk patients with NSTE-ACS admitted to 311 CABG-capable hospitals participating in Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes With Early Implementation of the American College of Cardiology/American Heart Association Guidelines (CRUSADE) from 2001 to 2003. A total of 8,395 patients (14%) underwent CABG during their initial hospital stay. A multivariate model was developed and identified 13 presenting clinical characteristics significantly associated with the likelihood of CABG (previous CABG, male gender, previous heart failure, diabetes, hyperlipidemia, renal insufficiency, ST depression and transient ST elevation, age > or = 75 years, previous percutaneous coronary intervention, family history of coronary artery disease, hypertension, trends in CABG rates, and previous stroke). This model had only modest predictive accuracy and calibration (c-index = 0.67). In conclusion, although certain presenting clinical features are associated with an increased likelihood of CABG in patients with NSTE-ACSs during the index hospitalization, it remains difficult to reliably identify, before diagnostic angiography, those who will subsequently undergo surgical revascularization.

Acute Disease↗

PubMed2006

Acute clopidogrel use and outcomes in patients with non-ST-segment elevation acute coronary syndromes undergoing coronary artery bypass surgery.

OBJECTIVES: We sought to characterize patterns of clopidogrel use before coronary artery bypass grafting (CABG) and examine the drug's impact on risks for postoperative transfusions among patients with non-ST-segment elevation acute coronary syndromes (NSTE ACS). BACKGROUND: Adherence in community practice to American College of Cardiology/American Heart Association guidelines for clopidogrel use among NSTE ACS patients has not been previously characterized. METHODS: We evaluated 2,858 NSTE ACS patients undergoing CABG at 264 hospitals participating in the CRUSADE (Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes With Early Implementation of the ACC/AHA Guidelines) Initiative. We examined the patterns of acute clopidogrel therapy and its association with bleeding risks among those having "early" CABG < or =5 days and again among those having "late" surgery >5 days after catheterization. RESULTS: Within 24 h of admission, 852 patients (30%) received clopidogrel. In contrast to national guidelines, 87% of clopidogrel-treated patients underwent CABG < or =5 days after treatment. Among those receiving CABG within < or =5 days of last treatment, the use of clopidogrel was associated with a significant increase in blood transfusions (65.0% vs. 56.9%, adjusted odds ratio [OR] 1.36, 95% confidence interval [CI] 1.10 to 1.68) as well as the need for transfusion of > or =4 U of blood (27.7% vs. 18.4%, OR 1.70, 95% CI 1.32 to 2.19). In contrast, acute clopidogrel therapy was not associated with higher bleeding risks if CABG was delayed >5 days (adjusted OR 1.18, 95% CI 0.54 to 2.58). CONCLUSIONS: Despite guideline recommendations, the overwhelming majority of NSTE ACS patients treated with acute clopidogrel needing CABG have their surgery within < or =5 days of treatment. A failure to delay surgery is associated with increased blood transfusion requirements that must be weighed against the potential clinical and economic impacts of such delays.

Aged↗

PubMed2006

Association between hospital process performance and outcomes among patients with acute coronary syndromes.

CONTEXT: Selected care processes are increasingly being used to measure hospital quality; however, data regarding the association between hospital process performance and outcomes are limited. OBJECTIVES: To evaluate contemporary care practices consistent with the American College of Cardiology/American Heart Association (ACC/AHA) guideline recommendations, to examine how hospital performance varied among centers, to identify characteristics predictive of higher guideline adherence, and to assess whether hospitals' overall composite guideline adherence was associated with observed and risk-adjusted in-hospital mortality rates. DESIGN, SETTING, AND PARTICIPANTS: An observational analysis of hospital care in 350 academic and nonacademic US centers of 64,775 patients enrolled in the CRUSADE (Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes With Early Implementation of the ACC/AHA Guidelines) National Quality Improvement Initiative between January 1, 2001, and September 30, 2003, presenting with chest pain and positive electrocardiographic changes or cardiac biomarkers consistent with non-ST-segment elevation acute coronary syndrome (ACS). MAIN OUTCOME MEASURES: Use of 9 ACC/AHA class I guideline-recommended treatments and the correlation among hospitals' use of individual care processes as well as overall composite adherence rates. RESULTS: Overall, the 9 ACC/AHA guideline-recommended treatments were adhered to in 74% of eligible instances. There was modest correlation in hospital performance among the individual ACS process metrics. However, composite adherence performance varied widely (median [interquartile range] composite adherence scores from lowest to highest hospital quartiles, 63% [59%-66%] vs 82% [80%-84%]). Composite guideline adherence rate was significantly associated with in-hospital mortality, with observed mortality rates decreasing from 6.31% for the lowest adherence quartile to 4.15% for the highest adherence quartile (P<.001). After risk adjustment, every 10% increase in composite adherence at a hospital was associated with an analogous 10% decrease in its patients' likelihood of in-hospital mortality (adjusted odds ratio, 0.90; 95% confidence interval, 0.84-0.97; P<.001). CONCLUSION: A significant association between care process and outcomes was found, supporting the use of broad, guideline-based performance metrics as a means of assessing and helping improve hospital quality.

Academic Medical Centers↗

PubMed2006

Impact of congestive heart failure in patients with non-ST-segment elevation acute coronary syndromes.

The presence of congestive heart failure (CHF) has been associated with treatment disparities and worse outcomes in patients with ST-segment elevation myocardial infarction, but the incidence and effect of CHF in patients with non-ST-segment elevation acute coronary syndromes (NSTE ACSs) has not been well characterized. We evaluated 45,744 patients with NSTE ACS (positive cardiac markers and/or ischemic ST-segment changes) who were treated at 424 hospitals in the CRUSADE Quality Improvement Initiative between March 2000 and March 2003. Treatment patterns and in-hospital outcomes in patients with signs of CHF on presentation and those who developed in-hospital CHF were compared with those in patients without CHF. In total, 10,398 patients (22.7%) had signs of CHF on presentation, and 1,664 patients (3.6%) later developed in-hospital CHF. Compared with patients without CHF, early (<24 hours from presentation) medications and invasive cardiac procedures were used less often in patients with signs of CHF on presentation. Likewise, patients with in-hospital CHF were less likely than those without CHF to receive acute antiplatelet agents and undergo cardiac catheterization but more likely to receive acute beta blockers, angiotensin-converting enzyme inhibitors, and heparin and to undergo coronary artery bypass grafting. Adjusted mortality was higher in patients with signs of CHF on presentation (odds ratio 2.64, 95% confidence interval 2.31 to 3.01) and those with in-hospital CHF (odds ratio 4.93, 95% confidence interval 4.05 to 5.99) than in patients without CHF. In conclusion, CHF occurs frequently in patients with NSTE ACS but is associated with less aggressive treatment and a higher risk of mortality. Further study is needed to determine the causes of these treatment differences and the optimal therapeutic approach for patients with NSTE ACS and concomitant CHF.

Adrenergic beta-Antagonists↗

PubMed2006

Clopidogrel to treat patients with non-ST-segment elevation acute coronary syndromes after hospital discharge.

BACKGROUND: Clopidogrel added to aspirin improved outcomes after hospitalization in patients with non-ST-segment elevation acute coronary syndromes (NSTE ACS) in the Clopidogrel in Unstable angina to prevent Recurrent Events (CURE) trial, regardless of in-hospital treatment approach. The American College of Cardiology/American Heart Association (ACC/AHA) Guidelines for treating NSTE ACS thus recommend prescribing clopidogrel plus aspirin at discharge for all patients, not just for those undergoing percutaneous coronary intervention (PCI). METHODS: We studied 61 052 patients with high-risk NSTE ACS (defined as the presence of positive cardiac markers and/or ischemic ST-segment changes) from January 2002 through December 2003 at 461 US hospitals participating in the CRUSADE (Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes With Early Implementation of the ACC/AHA Guidelines) Quality Improvement Initiative. We evaluated temporal trends of clopidogrel use at discharge since the ACC/AHA 2002 Guidelines update and examined variables associated with clopidogrel use in patients who did not undergo PCI. RESULTS: A total of 34 319 patients (56.2%) received clopidogrel when they were discharged from the hospital. Among patients who did not undergo PCI, variables associated with receiving clopidogrel at discharge included prior PCI, coronary artery bypass grafting (CABG), stroke, or myocardial infarction; hypercholesterolemia; elevated cardiac markers; and cardiology inpatient care. By late 2003, 96.3% of patients who underwent PCI received clopidogrel at discharge, compared with 42.8% of patients who did not undergo cardiac catheterization and 23.5% of the patients who underwent CABG, although clopidogrel prescription at discharge increased in each of these treatment groups from 2002 to 2003. CONCLUSION: Since release of the ACC/AHA Guidelines recommendations for treatment of NSTE ACS, prescription of clopidogrel at hospital discharge in patients with NSTE ACS who are treated with medical therapy alone and in those who undergo CABG has increased, but most of these patients still do not receive clopidogrel at discharge.

Aged↗

PubMed2006

Prospective multicenter study of quantitative pretest probability assessment to exclude acute coronary syndrome for patients evaluated in emergency department chest pain units.

STUDY OBJECTIVE: We compare the diagnostic accuracy of 3 methods--attribute matching, physician's written unstructured estimate, and a logistic regression formula (Acute Coronary Insufficiency-Time Insensitive Predictive Instrument, ACI-TIPI)--of estimating a very low pretest probability (< or = 2%) for acute coronary syndromes in emergency department (ED) patients evaluated in chest pain units. METHODS: We prospectively studied 1,114 consecutive patients from 3 academic EDs, evaluated for acute coronary syndrome. Physicians collected data required for pretest probability assessment before protocol-driven chest pain unit testing. A pretest probability greater than 2% was considered "test positive." The criterion standard was the outcome of acute coronary syndrome (death, myocardial infarction, revascularization, or > 60% stenosis prompting new treatment) within 45 days, adjudicated by 3 independent reviewers. RESULTS: Fifty-one of 1,114 enrolled patients (4.5%; 95% confidence interval [CI] 3.4% to 6.0%) developed acute coronary syndrome within 45 days, including 4 of 991 (0.4%; 95% CI 0.1% to 1.0%) patients, discharged after a negative chest pain unit evaluation result, who developed acute coronary syndrome. Unstructured estimate identified 293 patients with pretest probability less than or equal to 2%, 2 had acute coronary syndrome, yielding sensitivity of 96.1% (95% CI 86.5% to 99.5%) and specificity of 27.4% (95% CI 24.7% to 30.2%). Attribute matching identified 304 patients with pretest probability less than or equal to 2%; 1 had acute coronary syndrome, yielding a sensitivity of 98.0% (95% CI 89.6% to 99.9%) and a specificity of 26.1% (95% CI 23.6% to 28.7%). ACI-TIPI identified 56 patients; none had acute coronary syndrome, yielding sensitivity of 100% (95% CI 93.0% to 100%) and specificity of 6.1% (95% CI 4.7% to 7.9%). CONCLUSION: In a low-risk ED population with symptoms suggestive of acute coronary syndrome, patients with a quantitative pretest probability less than or equal to 2%, determined by attribute matching, unstructured estimate, or logistic regression, may not require additional diagnostic testing.

Acute Disease↗

PubMed2006

Frequency and clinical implications of discordant creatine kinase-MB and troponin measurements in acute coronary syndromes.

OBJECTIVES: We sought to evaluate the association between discordant cardiac marker results and in-hospital mortality and treatment patterns in patients with non-ST-segment elevation acute coronary syndromes (NSTE ACS). BACKGROUND: Creatine kinase-MB (CK-MB) and cardiac troponins (cTn) are often measured concurrently in patients with NSTE ACS. The significance of discordant CK-MB and cTn results is unknown. METHODS: Among 29,357 ACS patients in the CRUSADE initiative who had both CK-MB and cTn measured during the first 36 hours, we examined relationships of four marker combinations (CK-MB-/cTn-, CK-MB+/cTn-, CK-MB-/cTn+, and CK-MB+/cTn+) with mortality and American College of Cardiology/American Heart Association guidelines-recommended acute care. RESULTS: The CK-MB and cTn results were discordant in 28% of patients (CK-MB+/cTn-, 10%; CK-MB-/cTn+, 18%). In-hospital mortality was 2.7% among CK-MB-/cTn- patients; 3.0%, CK-MB+/cTn-; 4.5%, CK-MB-/cTn+; and 5.9%, CK-MB+/cTn+. After adjustment for other presenting risk factors, patients with CK-MB+/cTn- had a mortality odds ratio (OR) of 1.02 (95% confidence interval [CI] 0.75 to 1.38), those with CK-MB-/cTn+ had an OR of 1.15 (95% CI 0.86 to 1.54), and those with CK-MB+/cTn+ had an OR of 1.53 (95% CI 1.18 to 1.98). Despite variable risk, patients with CK-MB+/cTn- and CK-MB-/cTn+ were treated similarly with early antithrombotic agents and catheter-based interventions. CONCLUSIONS: Among patients with NSTE ACS, an elevated troponin level identifies patients at increased acute risk regardless of CK-MB status, but an isolated CK-MB+ status has limited prognostic value. Recognition of these risk differences may contribute to more appropriate early use of antithrombotic therapy and invasive management for all cTn+ patients.

Aged↗

PubMed2006

Relation between hospital specialization with primary percutaneous coronary intervention and clinical outcomes in ST-segment elevation myocardial infarction: National Registry of Myocardial Infarction-4 analysis.

BACKGROUND: Hospitals with primary percutaneous coronary intervention (PPCI) capability may choose to predominately offer PPCI to their patients with ST-segment elevation myocardial infarction (STEMI), or they may selectively offer PPCI or fibrinolytic therapy based on patient and hospital-level factors. Whether a greater level of hospital specialization with PPCI is associated with better quality of care is unknown. METHODS AND RESULTS: We analyzed data from the National Registry of Myocardial Infarction-4 to compare in-hospital mortality and times to treatment in STEMI across different levels of hospital specialization with PPCI. We divided 463 hospitals into quartiles of PPCI specialization based on the relative proportion of reperfusion-treated patients who underwent PPCI (< or =34.0%, >34.0 to 62.5%, >62.5 to 88.5%, >88.5%). Hierarchical multivariable regression assessed whether PPCI specialization was associated with better outcomes, after adjusting for patient and hospital characteristics, including PPCI volume. We found that greater PPCI specialization was associated with a lower relative risk of in-hospital mortality in patients treated with PPCI (adjusted relative risk comparing the highest and lowest quartiles, 0.64; P=0.006) but not in those treated with fibrinolytic therapy. Compared with patients at hospitals in the lowest quartile of PPCI specialization, adjusted door-to-balloon times in the highest quartile were significantly shorter (99.6 versus 118.3 minutes; P<0.001), and the likelihood of door-to-balloon times exceeding 90 minutes was significantly lower (relative risk, 0.78; P<0.001). Adjusting for PPCI specialization diminished the association between PPCI volume and clinical outcomes. CONCLUSIONS: Greater specialization with PPCI is associated with lower in-hospital mortality and shorter door-to-balloon times in STEMI patients treated with PPCI.

Angioplasty, Balloon↗

PubMed2006

Low-molecular-weight heparin compared with unfractionated heparin for patients with non-ST-segment elevation acute coronary syndromes treated with glycoprotein IIb/IIIa inhibitors: results from the CRUSADE initiative.

BACKGROUND: Both heparin and glycoprotein (GP) IIb/IIIa inhibitor therapy and early invasive management strategies are recommended by the American College of Cardiology (ACC)/American Heart Association (AHA) guidelines for the treatment of patients with non-ST-segment elevation acute coronary syndromes (NSTE ACS). However, controversy exists about which form of heparin-unfractionated (UF) or low-molecular-weight (LMW)-is preferable. We sought to compare the efficacy and safety of these treatment strategies in a large contemporary population of patients with NSTE ACS. METHODS: Using data from the CRUSADE Initiative, we evaluated LMWH and UFH in high-risk NSTE ACS patients (positive cardiac markers and/or ischemic ST-segment changes) who had received early (< 24 hours) GP IIb/IIIa inhibitor therapy and underwent early invasive management. In-hospital outcomes were compared among treatment groups. RESULTS: From a total of 11,358 patients treated at 407 hospitals in the US from January 2002-June 2003, 6881 (60.6%) received UFH and 4477 (39.4%) received LMWH. Patients treated with UFH were more often admitted to a cardiology inpatient service (73.6% vs. 65.5%, P < 0.0001) and more frequently underwent diagnostic catheterization (91.8% vs. 85.9%, P < 0.0001) and percutaneous coronary intervention (PCI) (69.7% vs. 56.9%, P < 0.0001) than patients treated with LMWH. The point estimate of the adjusted risk of in-hospital death or reinfarction was slightly lower among patients treated with LMWH (odds ratio [OR] 0.81, 95% confidence interval [CI] 0.67-0.99) and the risk of red blood cell transfusion was similar (OR 1.01, 95% CI 0.89-1.15). Among patients who underwent PCI within 48 hours, adjusted rates of death (OR 1.14, 95% CI 0.71-1.85), death or reinfarction (OR 0.93, 0.67-1.31), and transfusion (OR 1.16, 0.89-1.50) were similar. Patients who underwent PCI more than 48 hours into hospitalization had reduced rates of death (OR 0.64, 0.46-0.88), death or reinfarction (OR 0.57, 0.44-0.73), and transfusion (OR 0.66, 0.52-0.84). CONCLUSIONS: In routine clinical practice, patients treated with GP IIb/IIIa inhibitors have slightly improved outcomes and similar bleeding risks with LMWH than with UFH. These findings are consistent with current ACC/AHA guidelines but raise important questions about the safety and effectiveness of antithrombotic therapy in real-world clinical practice. Using data from the CRUSADE Initiative, we evaluated low-molecular-weight heparin (LMWH) and unfractionated heparin (UFH) in high-risk patients with non-ST-segment elevation acute coronary syndromes (NSTE ACS) who received early (<24 hours) glycoprotein (GP) IIb/IIIa inhibitors and early invasive management. In-hospital outcomes were compared among treatment groups. LMWH was associated with slightly improved clinical outcomes and similar rates of transfusion compared with UFH. Our results support the current ACC/AHA guidelines recommendations but raise concerns about the safety and efficacy of UFH in the setting of background use of upstream GP IIb/IIIa inhibitors for patients with NSTE ACS in routine clinical practice.

Aged↗

PubMed2006

The influence of risk status on guideline adherence for patients with non-ST-segment elevation acute coronary syndromes.

BACKGROUND: Practice guidelines for patients with non-ST-segment elevation (NSTE) acute coronary syndromes (ACS) recommend targeting evidence-based therapies for the highest-risk patients. We characterized guideline adherence for NSTE ACS by risk status. METHODS: We analyzed inhospital treatments and outcomes for 77760 patients with NSTE ACS (ischemic ST-segment changes and/or positive cardiac markers) included in the CRUSADE initiative from January 2001 to September 2003 at 457 US hospitals. Compliance with the American College of Cardiology/American Heart Association Class guideline recommendations for NSTE ACS was evaluated in subgroups of eligible patients without listed contraindications at increased risk for mortality and among risk categories designated by an adapted version of the PURSUIT risk model designed to predict inhospital mortality. RESULTS: Inhospital mortality was increased in patients with diabetes mellitus (5.8% vs 4.3%), renal insufficiency (10.0% vs 3.9%), signs of congestive heart failure on presentation (10.6% vs 3.1%), and age > or = 75 years (8.6% vs 2.7%), compared with patients without these features. Use of guideline-recommended acute medications, invasive cardiac procedures, and discharge medications and interventions was significantly lower in patients with these high-risk features. Patients designated as high-risk for inhospital mortality were less likely to be treated with guideline-recommended therapies compared with low-risk and moderate-risk patients. CONCLUSIONS: Patients with NSTE ACS with the highest risk of mortality are less likely to receive guideline-recommended therapies and interventions. These findings highlight the need to clarify guideline recommendations for high-risk patients and to develop novel quality improvement approaches that target undertreated subgroups of patients with NSTE ACS.

Acute Disease↗

PubMed2006

Clinical characteristics, process of care, and outcomes of Hispanic patients presenting with non-ST-segment elevation acute coronary syndromes: results from Can Rapid risk stratification of Unstable angina patients Suppress ADverse outcomes with Early implementation of the ACC/AHA Guidelines (CRUSADE).

BACKGROUND: Data regarding the management of non-ST-segment elevation acute coronary syndromes (NSTE ACS) in Hispanic patients, the largest and fastest-growing minority in the United States, are scarce. METHODS: We sought to describe the clinical characteristics, process of care, and outcomes of Hispanics presenting with NSTE ACS at US hospitals. We compared baseline characteristics, resource use, and inhospital mortality among 3936 Hispanics and 90280 non-Hispanic whites with NSTE ACS from the CRUSADE Quality Improvement Initiative. RESULTS: The regional distribution of Hispanics in CRUSADE paralleled that in the US Census. Hispanics were younger (65 vs 70 years, P < .0001) and had less hyperlipidemia (45.4% vs 49.0%, P < .0001) but were more likely to be hypertensive (72.2% vs 67.9%, P < .0001) and diabetic (46.5% vs 30.9%, P < .0001). Hispanics were also more likely to be uninsured (12.5% vs 5.1%, P < .001). During hospitalization, Hispanics were more often managed conservatively, undergoing stress tests more frequently (13.0% vs 10.1%, P < .0001), with less use of cardiac catheterization within 48 hours (48.7% vs 55.5%, P < .0001) or percutaneous coronary intervention (39.6% vs 46.4%, P < .0001) at any time. Hispanics received similar discharge treatments but were less frequently referred for cardiac rehabilitation (38.5% vs 49.2%, P < .0001). Adjusted inhospital mortality was similar in both groups (odds ratio 0.87, 95% CI 0.72-1.05). CONCLUSIONS: Although hispanics have a different risk factor profile and are treated less aggressively during hospitalization when they present with NSTE ACS, these treatment differences do not appear to affect inhospital outcomes. Further research is warranted to explore the long-term consequences of these findings.

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PubMed2006

The obesity paradox in non-ST-segment elevation acute coronary syndromes: results from the Can Rapid risk stratification of Unstable angina patients Suppress ADverse outcomes with Early implementation of the American College of Cardiology/American Heart Association Guidelines Quality Improvement Initiative.

BACKGROUND: Although obesity is a known risk factor for coronary artery disease, its impact on the presentation, treatment, and outcome of patients with acute coronary syndromes (ACS) has not been well studied. METHODS: Using data from the CRUSADE Initiative, we compared inhospital treatments and clinical outcomes of 80845 patients with high-risk non-ST-segment elevation (NSTE) ACS (positive cardiac markers and/or ischemic ST-segment changes) to determine whether there was an association with body mass index (BMI [kg/m2]). Patient weights were categorized according to World Health Organization classifications: Underweight (BMI <18.5), Normal range (BMI 18.5-24.9), Overweight (BMI 25-29.9), Obese Class I (BMI 30-34.9), Obese Class II (BMI 35-39.9), and Extremely Obese (BMI =40). RESULTS: Most (70.5%) of the CRUSADE patients were classified as overweight or obese; these patients were younger and more likely to present with comorbid conditions, including diabetes mellitus, hypertension, and hyperlipidemia. Medications given during the first 24 hours and invasive cardiac procedures recommended by the American College of Cardiology/American Heart Association guidelines for NSTE ACS were more commonly used in these patients. The incidence of death and death and reinfarction, adjusted for covariates, were generally lower in overweight and obese patients, compared with normal-weight patients, but higher in underweight and extremely obese patients. CONCLUSIONS: Most patients with NSTE ACS are overweight or obese. These patients receive more aggressive treatment, and, except for the extremely obese, have less adverse outcomes compared with underweight and normal-weight patients. Although obesity appears to be a risk factor for developing ACS at a younger age, it also appears to be associated with more aggressive ACS management and, ultimately, improved outcomes.

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