Biomedical subjects

C A Polanczyk

Publications and source records attributed to C A Polanczyk.

At least 19 recordsLinked to original sources

PubMed2002

Association between early detection of soluble TNF-receptors and mortality in burn patients.

OBJECTIVES: To describe early sequential profiling of circulating levels of tumor necrosis factor alpha (TNF-alpha), TNF-1 and TNF-2 soluble receptors (sTNFR1 and sTNFR2), and of endothelin (ET-1) in patients with severe burn injury, and its association with mortality. DESIGN: Prospective study. SETTING: Intensive Care Burn Unit at a community hospital. PATIENTS: Twenty patients with total burn surface area (TBSA)> or = 30%. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Patients were enrolled within 6 h from the injury. Blood samples were drawn at zero, 6, 12, and 24 h for sequential ELISA measurement of plasma marker levels. Data are expressed as mean+/-SD. Age, TBSA, and inhalation injury were not significantly different between survivors ( n=9; 30+/-13 years, TBSA 40+/-12%) and nonsurvivors ( n=11, 38+/-15 years, TBSA 56+/-20%). sTNFR1 levels were increased in nonsurvivors (2937+/-1676 pg/ml; 4548+/-1436 pg/ml) as compared to survivors (1313+/-561 pg/ml; 2561+/-804 pg/ml) at 6 h and 24 h, respectively ( P=0.01 and 0.002). sTNFR2 levels were significantly increased in nonsurvivors (4617+/-1,876 pg/ml vs 2611+/-1,326 pg/ml) only at 6 h ( P=0.015). TNF-alpha and ET-1 levels were not different between nonsurvivors and survivors. After adjustment for TBSA, sTNFR1 and sTNFR2 remained significantly higher in nonsurvivors. CONCLUSION: Early and progressive increase in sTNFR1 and sTNFR2 levels is associated with higher risk for poor outcome in severely burned patients.

APACHE↗

PubMed2001

Right heart catheterization and cardiac complications in patients undergoing noncardiac surgery: an observational study.

CONTEXT: Right heart catheterization (RHC) is commonly performed before high-risk noncardiac surgery, but the benefit of this strategy remains unproven. OBJECTIVE: To evaluate the relationship between use of perioperative RHC and postoperative cardiac complication rates in patients undergoing major noncardiac surgery. DESIGN: Prospective, observational cohort study. SETTING: Tertiary care teaching hospital in the United States. PATIENTS: Patients (n = 4059 aged >/=50 years) who underwent major elective noncardiac procedures with an expected length of stay of 2 or more days between July 18, 1989, and February 28, 1994. Two hundred twenty one patients had RHC and 3838 did not. MAIN OUTCOME MEASURE: Combined end point of major postoperative cardiac events, including myocardial infarction, unstable angina, cardiogenic pulmonary edema, ventricular fibrillation, documented ventricular tachycardia or primary cardiac arrest, and sustained complete heart block, classified by a reviewer blinded to preoperative data. RESULTS: Major cardiac events occurred in 171 patients (4.2%). Patients who underwent perioperative RHC had a 3-fold increase in incidence of major postoperative cardiac events (34 [15.4%] vs 137 [3.6%]; P<.001). In multivariate analyses, the adjusted odds ratios (ORs) for postoperative major cardiac and noncardiac events in patients undergoing RHC were 2.0 (95% confidence interval [CI], 1.3-3.2) and 2.1 (95% CI, 1.2-3.5), respectively. In a case-control analysis of a subset of 215 matched pairs of patients who did and did not undergo RHC, adjusted for propensity of RHC and type of procedure, patients who underwent perioperative RHC also had increased risk of postoperative congestive heart failure (OR, 2.9; 95% CI, 1.4-6.2) and major noncardiac events (OR, 2.2; 95% CI, 1.4-4.9). CONCLUSIONS: No evidence was found of reduction in complication rates associated with use of perioperative RHC in this population. Because of the morbidity and the high costs associated with RHC, the impact of this intervention in perioperative care should be evaluated in randomized trials.

Aged↗

PubMed2001

Impact of age on perioperative complications and length of stay in patients undergoing noncardiac surgery.

BACKGROUND: Major surgical procedures are performed with increasing frequency in elderly persons, but the impact of age on resource use and outcomes is uncertain. OBJECTIVE: To evaluate the influence of age on perioperative cardiac and noncardiac complications and length of stay in patients undergoing noncardiac surgery. DESIGN: Prospective cohort study. SETTING: Urban academic medical center. PATIENTS: Consecutive sample of 4315 patients 50 years of age or older who underwent nonemergent major noncardiac procedures. MEASUREMENTS: Major perioperative complications (cardiac and noncardiac), in-hospital mortality, and length of stay. RESULTS: Major perioperative complications occurred in 4.3% (44 of 1015) of patients 59 years of age or younger, 5.7% (93 of 1646) of patients 60 to 69 years of age, 9.6% (129 of 1341) of patients 70 to 79 years of age, and 12.5% (39 of 313) of patients 80 years of age or older (P < 0.001). In-hospital mortality was significantly higher in patients 80 years of age or older than in those younger than 80 years of age (0.7% vs. 2.6%, respectively). Multivariate analyses indicated an increased odds ratio for perioperative complications or in-hospital mortality in patients 70 to 79 years of age (1.8 [95% CI, 1.2 to 2.7]) and those 80 years of age or older (OR, 2.1 [CI, 1.2 to 3.6]) compared with patients 50 to 59 years of age. Patients 80 years of age or older stayed an average of 1 day more in the hospital, after adjustment for other clinical data (P = 0.001). CONCLUSIONS: Elderly patients had a higher rate of major perioperative complications and mortality after noncardiac surgery and a longer length of stay, but even in patients 80 years of age or older, mortality was low.

Age Factors↗

PubMed2001

Usefulness of transthoracic echocardiography as a tool for risk stratification of patients undergoing major noncardiac surgery.

Transthoracic echocardiography (TTE) is frequently ordered before noncardiac surgery, although its ability to predict perioperative cardiac complications is uncertain. To evaluate the incremental information provided by TTE after consideration of clinical data for prediction of cardiac complications after noncardiac surgery, 570 patients who underwent TTE before major noncardiac surgery at a university hospital were studied. Preoperative clinical data and clinical outcomes were collected prospectively according to a structured protocol. TTE data included left ventricular (LV) function, hypertrophy indexes, and Doppler-derived measurements. In univariate analyses, preoperative systolic dysfunction was associated with postoperative myocardial infarction (odds ratio [OR] 2.8, 95% confidence interval [CI] 1.1 to 7.0), cardiogenic pulmonary edema (OR 3.2, 95% CI 1.4 to 7.0), and major cardiac complications (OR 2.4, 95% Cl 1.3 to 4.5). Moderate to severe LV hypertrophy, moderate to severe mitral regurgitation, and increased aortic valve gradient were also associated with major cardiac events (OR 2.3, 95% CI 1.2 to 4.6; OR 2.2, 95% CI 1.1 to 4.3; OR 2.1, 95% CI 1.0 to 4.5, respectively). In logistic regression analysis, models with echocardiographic variables predicted major cardiac complications significantly better than those that included only clinical variables (c statistic 0.73 vs 0.68; p <0.05). Echocardiographic data added significant information for patients at increased risk for cardiac complications by clinical criteria, but not in otherwise low-risk patients. In conclusion, preoperative TTE before noncardiac surgery can provide independent information about the risk of postoperative cardiac complications in selected patients.

Aged↗

PubMed2001

Outcome following isolated tricuspid valve replacement.

OBJECTIVES: The clinical outcome of isolated tricuspid valve replacement is not well defined because this procedure is usually performed concomitantly with other valve surgery. METHODS: We retrospectively studied the short and long-term outcome of 15 consecutive patients (six men and nine women, aged 61+/-3 years) undergoing isolated tricuspid valve replacement from 1984 to 1996. The cause of valve dysfunction was rheumatic heart disease in 12 patients, healed endocarditis in two patients, and sarcoidosis in one patient. The tricuspid valve was stenotic in one patient, regurgitant in eight patients, and both stenotic and regurgitant in six patients. A St. Jude Medical prosthesis was placed in eight patients, Carpentier-Edwards in five patients, and Björk-Shiley and Starr-Edwards in one patient each. RESULTS: The median survival was only 1.2 years. Three patients (20%) died < or =30 days after the surgery or before discharge, and six other patients (40%) died within 3 years of surgery. Anasarca was the only predictor of short-term mortality (P=0.03), while the predictors of long-term mortality were anemia (P=0.01), rheumatic heart disease (P=0.04), previous stroke (P=0.04), and previous mitral valve surgery (P=0.04). CONCLUSIONS: Isolated tricuspid valve replacement is characterized by a poor short and long-term outcome.

Adult↗

PubMed2001

Quality of care and hospital readmission in congestive heart failure: an explicit review process.

BACKGROUND: The effect of hospital quality of care on hospital readmission for patients with congestive heart failure (CHF) has not been widely studied. METHODS AND RESULTS: We examined the effects of clinical factors, hospital quality of care, and cardiologist involvement on 3-month readmission rates in patients with CHF by using a 125-item explicit review instrument comprising 3 major domains: admission work-up, evaluation and treatment, and readiness for discharge. During the 3 months after discharge, 59 (30%) of 205 patients were readmitted for CHF. The average evaluation and treatment score was lower for readmitted patients (63% v 58%; P = .04). The specific quality criteria differing between patients readmitted or not readmitted included the performance of any diagnostic evaluation, performance of echocardiography in patients with unknown ejection fraction or suspected valvular disease, and therapy with an angiotensin-converting enzyme inhibitor on discharge. Patients with <or=50% of the evaluation and treatment criteria met were more likely to be readmitted (odds ratio, 2.5; 95% confidence interval, 1.1-5.3; P = .02). In a multivariate model including both clinical characteristics and quality criteria, a low evaluation and treatment score was an independent predictor of readmission. Cardiologist involvement was correlated with higher quality-of-care scores in the admission work-up (4.8% higher; P < .01) and evaluation and treatment (8.6% higher; P < .0001). CONCLUSIONS: Hospital quality of care for patients with CHF is independently associated with 3-month readmission rates, and cardiologist involvement during hospitalization is associated with overall quality of care.

Aged↗

PubMed2000

Three-dimensional return map: a new tool for quantification of heart rate variability.

BACKGROUND: Several methods are used to study heart rate variability, but they have limitations, which might be overcome by the use of a three-dimensional return map. OBJECTIVES: To evaluate the performance of three-dimensional return map-derived indices to detect (1) sympathetic and parasympathetic modulation to the sinus node and (2) autonomic dysfunction in diabetic patients. METHODS: Six healthy subjects underwent partial and total pharmacological autonomic blockade in a protocol that incorporated vagal and sympathetic predominance. Twenty-two patients with type 2 diabetes mellitus and 12 normal controls participated in the subsequent validation experiment. Three-dimensional return maps were constructed by plotting RRn intervals versus the difference between adjacent RR intervals [(RRn+1)-(RRn)] versus the number of counts, and four derived indices (P1, P2, P3, MN) were created for quantification. RESULTS: Both indices P1 and MN were significantly increased after sympathetic blockade with propranolol, while all indices except P1 were modified after parasympathetic blockade (P < 0.05). During the validation experiments, P1 and MN detected differences between normal controls, and diabetic patients with and without autonomic neuropathy. The overall accuracy of most three-dimensional indices to detect autonomic dysfunction, estimated by the area under the ROC curve, was significantly better than traditional time domain indices. Three-dimensional return map-derived indices also showed adequate reproducibility on two different recording days (intra-class correlation coefficients of 0.69 to 0.82; P < 0.001). CONCLUSIONS: Three-dimensional return map-derived indices are reproducible, quantify parasympathetic as well as sympathetic modulation to the sinus node, and are capable of detecting autonomic dysfunction in diabetic patients.

1-Propanol↗

PubMed2000

Ten-year trends in hospital care for congestive heart failure: improved outcomes and increased use of resources.

BACKGROUND: Scarce data are available on long-term trends in hospital mortality, length of stay (LOS), and costs in congestive heart failure (CHF). OBJECTIVE: To assess 10-year trends in the outcomes of patients hospitalized with CHF. METHODS: We studied all 6676 patients with a primary discharge diagnosis of CHF hospitalized from January 1, 1986, through July 31, 1996, at an academic tertiary care center. Hospital mortality, LOS, and costs were adjusted for sociodemographic characteristics, comorbidities, invasive procedures, hospital disposition, and LOS where appropriate. RESULTS: The mean (+/- SD) age of patients was 70+/-13 years; 54.1% were male; 87.0% were white. There was a significant increasing trend in heart failure severity as assessed by a CHF-specific risk-adjustment index. The proportion of patients who underwent invasive procedures (e.g., cardiac catheterization, coronary angioplasty, coronary artery bypass surgery, defibrillator and pacemaker implantation) was significantly higher in the 1994-1996 period. The standardized mortality ratio (observed mortality/predicted mortality) progressively fell during the study period. Compared with patients admitted before 1991, those admitted after 1991 had a 24% lower observed than predicted mortality. Adjusted LOS exhibited a downward trend, ie, 7.7 days in 1986-1987 to 5.6 days in 1994-1996 (P<.001). Unadjusted cost peaked during 1992-1993 and declined thereafter. Adjusted costs in 1994-1996 were not significantly different from those in 1990-1991. CONCLUSIONS: After risk adjustment for sociodemographic characteristics, comorbidities, and disease severity, a significant decrease in in-hospital mortality was observed during the study decade. This decline in hospital mortality occurred in parallel with decreasing LOS and increasing use of cardiac procedures and costs.

Aged↗

PubMed2000

Increased plasma levels of endothelin 1 and von Willebrand factor in patients with type 2 diabetes and dyslipidemia.

OBJECTIVE: Endothelial markers endothelin 1 (ET-1) and von Willebrand factor (vWF) were assessed in patients with type 2 diabetes and dyslipidemia and in patients with hypercholesterolemia. RESEARCH DESIGN AND METHODS: In this case-control study, plasma ET-and vWF levels were measured by enzyme-linked immunosorbent assay in 35 normoalbuminuric type 2 diabetic patients with dyslipidemia (56+/-5 years), in 21 nondiabetic patients with hypercholesterolemia (52+/-7 years), and in 19 healthy control subjects (45+/-4 years). All of the individuals were normotensive and nonsmokers. Urinary albumin was measured by immunoturbidimetry. RESULTS: ET-1 levels were higher (P<0.0001) in type 2 diabetic dyslipidemic patients (1.62+/-0.73 pg/ml) than in both nondiabetic hypercholesterolemic patients (0.91+/-0.73 pg/ml) and control subjects (0.69+/-0.25 pg/ml). vWF levels were significantly increased (P = 0.02) in type 2 diabetic (185.49+/-72.1%) and hypercholesterolemic (163.29+/-50.7%) patients compared with control subjects (129.70+/-35.2%). In the multiple linear regression analysis. ET-1 was significantly associated (adjusted r2 = 0.42) with serum triglyceride levels (P<0.001), age (P<0.01), insulin sensitivity index (P<0.02), and albuminuria levels (P<0.04). vWF levels were associated (adjusted r2 = 0.22) with albuminuria (P<0.001), fibrinogen levels (P<0.02), and BMI (P<0.03). CONCLUSIONS: Compared with hypercholesterolemic patients, type 2 diabetic patients with dyslipidemia have increased levels of ET-1 and vWF which may indicate more pronounced endothelial injury. These findings appear to be related to components of the insulin resistance syndrome.

Albuminuria↗

PubMed1999

Emergency department triage strategies for acute chest pain using creatine kinase-MB and troponin I assays: a cost-effectiveness analysis.

BACKGROUND: Evaluation of acute chest pain is highly variable. OBJECTIVE: To evaluate the cost-effectiveness of strategies using cardiac markers and noninvasive tests for myocardial ischemia. DESIGN: Cost-effectiveness analysis. DATA SOURCES: Prospective data from 1066 patients with chest pain and from the published literature. TARGET POPULATION: Patients admitted with acute chest pain. TIME HORIZON: Lifetime. PERSPECTIVE: Societal. INTERVENTIONS: Creatine kinase (CK)-MB mass assay alone; CK-MB mass assay followed by cardiac troponin I assay if the CK-MB value is normal; CK-MB mass assay followed by troponin I assay if the CK-MB value is normal and electrocardiography shows ischemic changes; both CK-MB mass and troponin I assays; and troponin I assay alone. These strategies were evaluated alone or in combination with early exercise testing. OUTCOME MEASURES: Lifetime cost, life expectancy (in years), and incremental cost-effectiveness. RESULTS OF BASE-CASE ANALYSIS: For patients 55 to 64 years of age, measurement of CK-MB mass followed by exercise testing in appropriate patients was the most competitive strategy ($43000 per year of life saved). Measurement of CK-MB mass followed by troponin I measurement had an incremental cost-effectiveness ratio of $47400 per year of life saved for patients 65 to 74 years of age; it was also the most cost-effective strategy when early exercise testing could not be performed, CK-MB values were normal, and ischemic changes were seen on electrocardiography. RESULTS OF SENSITIVITY ANALYSIS: Results were influenced by age, probability of myocardial infarction, and medical costs. CONCLUSIONS: Measurement of CK-MB mass plus early exercise testing is a cost-effective initial strategy for younger patients and those with a low to moderate probability of myocardial infarction. Troponin I measurement can be a cost-effective second test in higher-risk subsets of patients if the CK-MB level is normal and early exercise testing is not an option.

Biomarkers↗

PubMed1999

Derivation and prospective validation of a simple index for prediction of cardiac risk of major noncardiac surgery.

BACKGROUND: Cardiac complications are important causes of morbidity after noncardiac surgery. The purpose of this prospective cohort study was to develop and validate an index for risk of cardiac complications. METHODS AND RESULTS: We studied 4315 patients aged > or = 50 years undergoing elective major noncardiac procedures in a tertiary-care teaching hospital. The main outcome measures were major cardiac complications. Major cardiac complications occurred in 56 (2%) of 2893 patients assigned to the derivation cohort. Six independent predictors of complications were identified and included in a Revised Cardiac Risk Index: high-risk type of surgery, history of ischemic heart disease, history of congestive heart failure, history of cerebrovascular disease, preoperative treatment with insulin, and preoperative serum creatinine >2.0 mg/dL. Rates of major cardiac complication with 0, 1, 2, or > or = 3 of these factors were 0.5%, 1.3%, 4%, and 9%, respectively, in the derivation cohort and 0.4%, 0.9%, 7%, and 11%, respectively, among 1422 patients in the validation cohort. Receiver operating characteristic curve analysis in the validation cohort indicated that the diagnostic performance of the Revised Cardiac Risk Index was superior to other published risk-prediction indexes. CONCLUSIONS: In stable patients undergoing nonurgent major noncardiac surgery, this index can identify patients at higher risk for complications. This index may be useful for identification of candidates for further risk stratification with noninvasive technologies or other management strategies, as well as low-risk patients in whom additional evaluation is unlikely to be helpful.

Aged↗

PubMed1999

A proposed strategy for utilization of creatine kinase-MB and troponin I in the evaluation of acute chest pain.

In recent years, cardiac troponins have attracted great interest as a marker for myocardial injury. However, there are limited data on strategies for use of creatine kinase (CK)-MB and troponin I (cTnI) in clinical practice. We sought to develop a testing strategy using prospectively collected clinical data including serial CK-MB and cTnI levels from 1,051 patients aged > or = 30 years admitted to a teaching hospital for acute chest pain. Diagnostic performance was evaluated for peak values of CK-MB and cTnI obtained during the first 24 hours for the combined end point of acute myocardial infarction and/or major cardiac events within 72 hours. The overall diagnostic accuracy was similar for both cardiac markers alone, and for the combination of cTnI and CK-MB (receiver-operating characteristic curve 0.84, 0.86, and 0.87, respectively). In the multivariate analysis, models including cardiac markers showed that both CK-MB and cTnI added information to clinical data to predict the combined end point, but cTnI added significantly less. Using recursive partitioning analysis, we developed a strategy that would restrict routine cTnI use to patients with normal CK-MB results and findings on the electrocardiogram consistent with ischemia. This strategy would divide patients with suspected myocardial ischemia into 4 groups with risks for the combined end point of 4%, 13%, 26%, and 85%. Thus, cTnI adds information to CK-MB mass and clinical data for predicting major cardiac events, but this contribution is mainly in patients with evidence of myocardial ischemia on their electrocardiograms.

Acute Disease↗

PubMed1999

Value of additional two-hour myoglobin for the diagnosis of myocardial infarction in the emergency department.

Myoglobin has been described as an early marker of myocardial injury. It increases within 1 to 3 hours of myocardial injury, and falls back to normal early after the event. Few data suggest that myoglobin can be used to triage patients with chest pain. To assess the diagnostic utility of second myoglobin levels drawn within 2 to 3 hours after presentation to the emergency department for detecting myocardial infarction, we prospectively collected myoglobin levels in 368 patients aged > or = 30 years who were admitted with chest pain. Myoglobin levels were measured at admission and 2 to 3 hours later. Sensitivity and specificity for detecting acute myocardial infarction for a twofold increase in myoglobin level from baseline were 39% and 98%, respectively. The early diagnostic performance of myoglobin at admission, the second level drawn 2 to 3 hours later, and creatine kinase-MB mass drawn at admission were similar (receiver-operating characteristic curves 0.80, 0.86, and 0.85). The diagnostic performance of each of these markers was significantly superior to the absolute change from baseline to second myoglobin (receiver-operating characteristic curve 0.77). In patients who presented within 4 hours of symptom onset, myoglobin drawn 2 to 3 hours later had the highest yield for detecting myocardial infarction. These results suggest that serial myoglobin measurement aiming to detect changes over time is not superior to single marker determinations. Myoglobin measured in 2 to 3 hours from admission may be helpful in triaging patients who present within 4 hours from onset of symptoms.

Creatine Kinase↗

PubMed1999

Weekend and holiday exercise testing in patients with chest pain.

OBJECTIVE: To determine the outcome, safety, and possible cost savings of patients undergoing weekend or holiday exercise treadmill testing. DESIGN: Medical records of all 195 patients scheduled for weekend and holiday exercise testing were reviewed, and 77.9% of patients were contacted by telephone to ascertain medical outcomes and need for further emergency department or inpatient care. Costs were calculated from estimates of days of hospitalization saved and incremental costs incurred in conjunction with weekend or holiday testing. SETTING: Urban tertiary care academic medical center. PATIENTS: A total of 195 patients were scheduled for testing, and 181 tests were performed. Over three quarters (75.1%) of patients underwent testing for assessment of chest pain. Other indications included risk stratification after myocardial infarction or coronary angioplasty or prior to noncardiac surgery, or evaluation for arrhythmias, dyspnea, or syncope. MEASUREMENTS AND MAIN RESULTS: Outcomes included results and complications of testing, hospital course after testing, subsequent emergency department visits and readmissions, myocardial infarction, need for cardiac catheterization or revascularization, and mortality. No complications were noted during testing. In 136 patients tested for the indication of chest pain, 90 (66.2%) had negative tests, 39 (28. 7%) were intermediate, and 6 (4.4%) were positive for ischemia. Same day discharge occurred in 115 (84.6%) of the patients, saving an estimated 185 days of hospitalization ($316.83 per patient tested). Event rates over the 6 months following discharge were low. CONCLUSIONS: Weekend and holiday exercise testing is a safe and effective means of risk stratification prior to hospital discharge for patients with chest pain. It also reduces length of stay and is cost saving.

Academic Medical Centers↗

PubMed1999

Management of patients with acute myocardial infarction at five academic medical centers: clinical characteristics, resource utilization, and outcome.

BACKGROUND: Although variability in management of cardiovascular syndromes has been demonstrated among regions, the extent to which variability exists among academic medical centers in different countries in uncertain. METHODS: This retrospective cohort study includes data on consecutive patients (n = 694) with acute myocardial infarction who were admitted to five teaching hospitals from different countries (84, Brigham and Women's Hospital, USA; 97, Iizuka Hospital, Japan; 64, Hospital de Clinicas de Porto Alegre, Brazil; 62, Universitätsklinikum Charité, Germany; and 387, Hôpital Cantonal Universitaire de Genève, Switzerland) during a one-year period. Data were collected via chart review on clinical characteristics, rates of diagnostic and therapeutic interventions, complications and mortality, length of stay, and one-year follow-up outcomes. RESULTS: Patients' clinical characteristics varied among these institutions, with the lowest prevalence of antero-septal myocardial infarction at the US hospital. The US hospital had the lowest rate of use of thrombolytic therapy and did not have the highest rate for any invasive procedure. Average length of stay ranged from 7.7 +/- 4.3 days in the US hospital to 47.2 +/- 27.9 days in the Japanese hospital. There were no differences in one-year mortality among the four institutions (4% to 8%, P = 0.881) for which data were available. CONCLUSIONS: In this nonrandom sample of academic medical centers, the use of aggressive therapies for acute myocardial infarction was at least as common at non-US as US hospitals. Length of stay was much shorter at the US hospital. Despite these variations in management, evidence for differences in outcomes at one year were not detected.

Academic Medical Centers↗

PubMed1998

Supraventricular arrhythmia in patients having noncardiac surgery: clinical correlates and effect on length of stay.

BACKGROUND: Few recent data are available on risk factors for perioperative supraventricular arrhythmia (SVA) after noncardiac surgery or on the effect of SVA on clinical outcomes. OBJECTIVE: To determine the incidence, clinical correlates, and effect on length of stay of perioperative SVA in patients having major noncardiac surgery. DESIGN: Prospective cohort study. SETTING: Urban tertiary care teaching hospital. PARTICIPANTS: 4181 patients 50 years of age or older who had major, nonemergency, noncardiac procedures and were in sinus rhythm at the preoperative evaluation. MEASUREMENTS: Preoperative clinical data, postoperative enzyme data, serial electrocardiograms, and clinical outcomes were collected prospectively. Outcomes were 1) SVA that persisted or led to treatment and 2) increase in length of stay attributable to SVA. RESULTS: Perioperative SVA occurred in 317 patients (7.6%); it occurred in 83 patients (2.0%) during surgery and in 256 (6.1%) after surgery. Independent preoperative correlates of SVA were male sex (odds ratio [OR], 1.3 [95% CI, 1.0 to 1.7]), age 70 years or older (OR, 1.3 [CI, 1.0 to 1.7]), significant valvular disease (OR, 2.1 [CI, 1.2 to 3.6]), history of SVA (OR, 3.4 [CI, 2.4 to 4.8]) or asthma (OR, 2.0 [CI, 1.3 to 3.1]), congestive heart failure (OR, 1.7 [CI, 1.1 to 2.7]), premature atrial complexes on preoperative electrocardiography (OR, 2.1 [CI, 1.3 to 3.4]), American Society of Anesthesiologists class III or IV (OR, 1.4 [CI, 1.1 to 1.9]), and type of procedure: abdominal aortic aneurysm (OR, 3.9 [CI, 2.4 to 6.3]) or abdominal (OR, 2.5 [CI, 1.7 to 3.6]), vascular (OR, 1.6 [CI, 1.1 to 2.4]), and intrathoracic (OR, 9.2 [CI, 6.7 to 13]) procedures. Among patients who had intrathoracic surgery, those receiving digoxin were at lower risk (OR, 0.2 [CI, 0.04 to 0.8]) for SVA than those not receiving digoxin. Patients with perioperative acute cardiac and noncardiac events had high relative risks for SVA. Supraventricular arrhythmia was associated with a 33% increase in length of stay after adjustment for other clinical data (P < 0.001). CONCLUSIONS: In this cohort, SVA was common after noncardiac surgery and was associated with prolonged length of stay.

Aged↗

PubMed1998

Clinical correlates and prognostic significance of early negative exercise tolerance test in patients with acute chest pain seen in the hospital emergency department.

An exercise tolerance test (ETT) is often performed to identify patients for early discharge after observation for acute chest pain, but the safety of this strategy is unproven. We prospectively studied 276 low-risk patients who underwent an ETT within 48 hours after presentation to the emergency department with acute chest pain. The ETT was considered negative if subjects achieved at least stage I of the Bruce protocol and the electrocardiogram showed no evidence of ischemia. There were no complications associated with ETT performance. The ETT was negative in 195 patients (71%); there was no identifiable subsets of patients at very low probability of an abnormal test. During the 6-month follow-up, patients with a negative ETT had fewer additional visits to the emergency department (17% vs 21%, respectively; p < 0.05) and fewer readmissions to the hospital (12% vs 17%; p < 0.01) than those with positive or inconclusive ETTs. No patient with a negative ETT died and only 4 patients with a negative ETT experienced a major cardiac event (myocardial infarction, coronary angioplasty, or bypass) within 6 months. Among these 4 patients, only 1 had an event within 4 months. In conclusion, our results suggest that ETT can be safely used to identify patients at low risk of subsequent events. Patients without a clearly negative test are at increased risk for readmission and cardiac events, and should be reevaluated either during the same admission or shortly after discharge.

Aged↗

PubMed1998

Sympathetic nervous system representation in time and frequency domain indices of heart rate variability.

This study evaluated the contributions of sympathetic and parasympathetic modulation to heart rate variability during situations in which vagal and sympathetic tone predominated. In a placebo-controlled, randomized, double blind blockade study, six young healthy male individuals received propranolol (0.2 mg x kg(-1)), atropine (0.04 mg x kg(-1)), propranolol plus atropine, or placebo infusions over 4 days. Time-domain indices were calculated during 40 min of rest and 20 min of exercise at 70% of maximal exercise intensity. Spectrum analysis, using fast Fourier transformation, was also performed at rest and during the exercise. The time-domain indices standard deviation of R-R intervals, mean of the standard deviations of all R-R intervals for all 5-min segments, percentage of number of pairs of adjacent R-R intervals differing by more than 50 ms, and square root of the mean of the sum of squares of differences between adjacent R-R intervals were reduced after atropine and propranolol plus atropine. Propranolol alone caused no appreciable change in any of the time-domain indices. At rest, all spectrum components were similar after placebo and propranolol infusions, but following parasympathetic and double autonomic blockade there was a reduction in all components of the spectrum analysis, except for the low:high ratio. During exercise, partial and double blockade did not change significantly any of the spectrum components. Thus, time and frequency-domain indices of heart rate variability were able to detect vagal activity, but could not detect sympathetic activity. During exercise, spectrum analysis is not capable of evaluating autonomic modulation of heart rate.

Adult↗