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Peter B Berger

Publications and source records attributed to Peter B Berger.

At least 37 records · Page 2Linked to original sources
PubMed2005

In-hospital and long-term outcomes of multivessel percutaneous coronary revascularization after acute myocardial infarction.

Multivessel percutaneous coronary intervention (PCI) early after acute myocardial infarction (AMI) is discouraged because of the potential for increased complications. However, with recent advances in PCI, the safety and long-term outcomes of multivessel PCI are unknown. We evaluated the outcomes of multivessel PCI early after AMI (ST-elevation and non-ST-elevation AMI). We identified all patients who had multivessel disease and underwent PCI within 7 days after an AMI from 1997 to 2002. Clinical outcomes were compared between patients who underwent multivessel PCI (n = 239) and patients who underwent treatment of the infarct-related artery alone (n = 1,145). The primary end point was cumulative survival at 6, 12, and 36 months. Secondary end points included a composite of mortality, recurrent infarction, coronary artery bypass graft, or target vessel revascularization at the same time points. There were 138 deaths and 351 occurrences of the composite end point during follow-up. The multivessel PCI group had a significantly higher prevalence of adverse prognostic indicators. Despite this, observed event rates were similar between the multivessel PCI and 1-vessel PCI groups. The Kaplan-Meier estimated 1-year survival was 0.91 (95% confidence interval [CI] 0.87 to 0.95) for the multivessel PCI group and 0.93 (95% CI 0.92 to 0.95) for the 1-vessel PCI group (p = 0.43). Similarly, 1-year survival free of recurrent infarction and target vessel revascularization rates were similar between the 2 groups: multivessel PCI 0.78 (95% CI 0.73 to 0.84) and 1-vessel PCI 0.78 (95% CI 0.75 to 0.81). Multivessel PCI in patients with multivessel coronary artery disease after AMI compared with 1-vessel PCI was not associated with an excess risk of death or of combined death, myocardial infarction, coronary artery bypass graft, or target vessel revascularization.

Aged↗
PubMed2005

Percutaneous coronary intervention and adjunctive pharmacotherapy in women: a statement for healthcare professionals from the American Heart Association.

More than 1.2 million percutaneous coronary interventions are performed annually in the United States, with only an estimated 33% performed in women, despite the established benefits of percutaneous coronary intervention and adjunctive pharmacotherapy in reducing fatal and nonfatal ischemic complications in acute myocardial infarction and high-risk acute coronary syndromes. This statement reviews sex-specific data on the safety and efficacy of contemporary interventional therapies in women.

Angioplasty, Balloon, Coronary↗
PubMed2005

Variability in platelet responsiveness to clopidogrel among 544 individuals.

OBJECTIVES: We sought to describe the responses of patients to clopidogrel using ex vivo measures of platelet aggregation and activation in a large, heterogeneous population. BACKGROUND: Recently, a number of reports, using various definitions, have dichotomized patients who are treated with clopidogrel into a minority of "non-responders" and a majority of "responders." Such classifications imply that treatment leads to an all-or-none response, with potentially important clinical implications. METHODS: We conducted secondary post-hoc analyses of a dataset consisting of volunteers (n = 94) and patients after coronary stenting (n = 405), with heart failure (n = 25), and after stroke (n = 20). RESULTS: The response of subjects to clopidogrel followed a normal, bell-shaped distribution, with a mean and standard deviation of 41.9 +/- 20.8% when aggregation was induced by 5 mumol/l of adenosine diphosphate. When hyporesponsiveness and hyper-responsiveness to clopidogrel were considered to be two standard deviations less than and greater than the mean, respectively, the prevalence of hyporesponsiveness and hyper-responsiveness in these patients was 4.2% and 4.8%, respectively. Pretreatment platelet activity and clinical characteristics were not associated with responsiveness to clopidogrel. CONCLUSIONS: Individuals receiving clopidogrel exhibit a wide variability in response that follows a normal distribution. The clinical implications of this variability are unknown but potentially are important. Clinical trials are needed to define whether hyporesponders to clopidogrel are at increased risk for thrombotic events and whether hyper-responders are at increased risk for bleeding. If so, the individualization of antiplatelet therapy, including clopidogrel dosing, may be possible in the future but will require the ability to easily and reproducibly measure responsiveness by a method that has been proven to be predictive of clinical events.

Aged↗
PubMed2005

Identification, diagnosis and treatment of heparin-induced thrombocytopenia and thrombosis: a registry of prolonged heparin use and thrombocytopenia among hospitalized patients with and without cardiovascular disease. The Complication After Thrombocytopenia Caused by Heparin (CATCH) Registry steering committee.

BACKGROUND: Heparin-induced thrombocytopenia (HIT) is estimated to occur in 1-5% of all patients receiving heparin, and 25-50% of such cases develop heparin-induced thrombocytopenia with thrombosis (HITT) A conservative estimate based only on cardiovascular patients suggests that in the United States approximately 100,000 patients develop thrombocytopenia, and 25-50,000 develop HITT annually. Both HIT and HITT are associated with high morbidity and mortality and represent substantial worldwide public health concerns. REGISTRY DESIGN: The objective of the Complication After Thrombocytopenia Caused by Heparin (CATCH) Registry is to identify the incidence of HIT and/or HITT in patients treated with systemic heparin (unfractionated or low molecular weight heparin) in contemporary practice. Additional objectives include to: (1) provide a comprehensive database of patients with suspected HIT or HITT, (2) monitor and define clinical events, including thrombocytopenia, thrombosis, and mortality among patients treated with prolonged (> 96 hours) heparin, (3) describe the incidence and outcomes of HIT and HITT in patients who are treated with heparin and who develop thrombocytopenia in the Coronary Care Unit setting, and (4) document and characterize current diagnostic and therapeutic strategies of suspected HIT. The unblinded registry will record approximately 5,000 patients at 60-80 US hospitals with either prolonged systemic heparin administration or thrombocytopenia and those with suspected HIT or HITT. Enrollment began in the first quarter 2003 and was completed at the end of 2004. IMPLICATIONS: The registry will provide valuable insights to the incidence and consequences of HIT and HITT that will enable improvements in diagnosis and treatment.

Cardiovascular Diseases↗
PubMed2005

The relation of renal function to ischemic and bleeding outcomes with 2 different glycoprotein IIb/IIIa inhibitors: the do Tirofiban and ReoPro Give Similar Efficacy Outcome (TARGET) trial.

BACKGROUND: Renal function significantly impacts morbidity and mortality after a percutaneous coronary intervention. Platelet glycoprotein (GP) IIb/IIIa inhibitors reduce ischemic complications during percutaneous coronary intervention; little is known of whether their safety and efficacy are influenced by renal function. In particular, whether outcome differences exist between agents that are renally excreted (tirofiban) or not (abciximab) in patients with mild renal impairment is not known. METHODS: The TARGET trial randomized 4623 patients to tirofiban or abciximab. In this analysis, patients were grouped in creatinine clearance quartiles (<70, 70-90, 90-114, >114 mL/min) and analyzed for efficacy and bleeding risk. Univariate and multivariate analyses were performed to identify interactions between GP IIb/IIIa inhibitor used and creatinine clearance with respect to ischemic outcomes and bleeding. RESULTS: Using unadjusted logistic regression tests for trend, 30-day death/myocardial infarction/urgent target vessel revascularization was greater in patients with lower creatinine clearances (7.3%, 8.5%, 5.1%, and 5.8%, P = .005), as were both major and minor bleeding. There was no interaction between assigned GP IIb/IIIa inhibitor, creatinine clearance and ischemic outcome, major bleeding or minor bleeding. CONCLUSIONS: Both ischemic and bleeding complications are highest in the lowest creatinine clearance quartile of patients treated with GP IIb/IIIa inhibitors. Although tirofiban is renally cleared and abciximab is not, there was no interaction between these GP IIb/IIIa inhibitors and creatinine clearance regarding ischemic or bleeding events.

Abciximab↗
PubMed2005

Can N-acetylcysteine reverse the antiplatelet effects of clopidogrel? An in vivo and vitro study.

BACKGROUND: The active metabolite of clopidogrel binds the P2Y12 ADP receptor on the platelet surface via a disulfide bond. N-Acetylcysteine (NAC) is able to reduce disulfide bonds. We postulated that NAC might reverse clopidogrel's effect on platelets. METHODS: Two groups of patients were investigated. Group 1 included 11 patients with stable coronary disease who, after discontinuation of aspirin, received 14 days of clopidogrel, 75 mg/day. Bleeding time and whole-blood platelet aggregometry (with 5 micromol/L ADP) were compared before and after the 14 days. Patients were then treated with 6 g of NAC orally, followed by repeat measurement of bleeding time and aggregometry. In group 2, 14 patients were treated with clopidogrel (300 mg) and aspirin before a percutaneous coronary intervention. Blood was drawn 22 +/- 3 hours later and divided into 2 samples. One was sent immediately for platelet-rich plasma aggregometry (using 5 and 2 micromol/L ADP, collagen, and arachidonic acid as agonists), thromboelastography, and aggregometry using the Plateletworks assay (Helena Laboratories, Beaumont, Tex). The other sample was treated with NAC (500 mg/L), after which these same platelet function tests were performed. RESULTS: In group 1, NAC therapy did not significantly change the bleeding time or results of aggregometry. In group 2, neither aggregometry nor the Plateletworks assay suggested reversal of inhibition by NAC. CONCLUSIONS: These studies reveal that a large dose of NAC does not reduce inhibition of platelet aggregation by clopidogrel in vitro or in vivo.

Acetylcysteine↗
PubMed2005

A global view of atherothrombosis: baseline characteristics in the Clopidogrel for High Atherothrombotic Risk and Ischemic Stabilization, Management, and Avoidance (CHARISMA) trial.

BACKGROUND: The manifestations of atherothrombosis such as myocardial infarction, ischemic stroke, limb ischemia, or cardiovascular death pose a global health care burden. Additional therapies to decrease ischemic events in patients with established vascular disease or at risk for developing vascular disease are necessary. We sought to characterize the risk factors and treatments of a diverse contemporary population of patients with atherothrombosis. METHODS: The CHARISMA trial has enrolled 15,603 patients from around the world. Patients with established coronary, cerebrovascular, or peripheral arterial disease, or those at high risk of developing atherothrombosis due to multiple risk factors, have been randomized to receive either the adenosine diphosphate receptor antagonist clopidogrel or placebo, in addition to background therapy with low- to moderate-dose aspirin. RESULTS: A high percentage of enrolled patients are being treated with statins and angiotensin-converting enzyme inhibitors. In the CHARISMA population, a total of 75.6% of the population had an abnormal body mass index: 42.2% were overweight and 33.4% were obese, with particularly high rates in the United States, especially of morbid obesity. Correspondingly, the prevalence of diabetes was 42%. CONCLUSION: The CHARISMA trial will further characterize atherothrombosis and provide insight into the role of dual antiplatelet therapy in improving outcomes in patients with multiple risk factors or established vascular disease. Of note, the rates of obesity and diabetes in patients with atherothrombosis throughout the world are particularly alarming.

Adult↗
PubMed2004

Influence of treatment duration with a 600-mg dose of clopidogrel before percutaneous coronary revascularization.

OBJECTIVES: We examined clinical outcomes in the Intracoronary Stenting and Antithrombotic Regimen-Rapid Early Action for Coronary Treatment (ISAR-REACT) trial based on the duration of pretreatment with a 600-mg loading dose of clopidogrel. BACKGROUND: The influence of the treatment duration with a 600-mg dose of clopidogrel before percutaneous coronary revascularization on early outcomes remains uncertain. METHODS: Among 2,159 patients with coronary disease who underwent percutaneous coronary intervention (PCI) in the ISAR-REACT trial, we examined clinical outcomes relative to the duration of pretreatment with a 600-mg dose of clopidogrel: (2 to 3 h, 3 to 6 h, 6 to 12 h, or >12 h). Patients were randomly assigned to adjunctive therapy with abciximab or placebo at the beginning of the study. The primary end point was a composite of death, myocardial infarction, or urgent revascularization within 30 days after randomization. RESULTS: No significant differences were observed between patient groups regarding the duration of pretreatment, irrespective of assignment to abciximab or placebo (p = 0.27 for interaction among abciximab/clopidogrel and placebo/clopidogrel treatment at each time interval). Occurrence of major bleeding also did not differ according to time of initial clopidogrel dosing. CONCLUSIONS: For low-to-intermediate risk patients treated with a 600-mg loading dose of clopidogrel before PCI, incremental clinical benefit within the first 30 days from durations of pretreatment >2 to 3 h was not evident.

Abciximab↗
PubMed2004

Association of lipoprotein-associated phospholipase A2 levels with coronary artery disease risk factors, angiographic coronary artery disease, and major adverse events at follow-up.

AIMS: We aimed to evaluate the association of lipoprotein-associated phospholipase A2 (Lp-PLA2) with coronary artery disease (CAD) risk factors, with the severity of angiographic CAD, and with the incidence of major adverse events. METHODS AND RESULTS: We measured Lp-PLA2 levels in 504 consecutive patients undergoing clinically indicated coronary angiography. Mean age was 60+/-11 years and 38% were women. The mean (+/-SD) Lp-PLA2 level (ng/mL) was 245+/-91. Lp-PLA2 levels correlated with male gender, LDL, HDL, and total cholesterol, fibrinogen, and creatinine. Lp-PLA2 levels correlated with the extent of angiographic CAD on univariate but not on multivariable analysis. During a median follow-up of 4.0 years, 72 major adverse events occurred in 61 of 466 (13%) contacted patients (20 deaths, 14 myocardial infarctions, 28 coronary revascularizations, and 10 strokes). Higher Lp-PLA2 levels were associated with a greater risk of events: the hazard ratio per SD was 1.28 (95% CI 1.06-1.54, P=0.009), and remained significant after adjusting for clinical and lipid variables and C-reactive protein. CONCLUSION: Higher Lp-PLA2 levels were associated with a higher incidence of major adverse events at follow-up, independently of traditional CAD risk factors and C-reactive protein.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗
PubMed2004

Utilization of early invasive management strategies for high-risk patients with non-ST-segment elevation acute coronary syndromes: results from the CRUSADE Quality Improvement Initiative.

CONTEXT: The American College of Cardiology/American Heart Association (ACC/AHA) guidelines for the management of non-ST-segment elevation acute coronary syndromes (NSTE ACS) recommend early invasive management for high-risk patients, given the benefits with this approach demonstrated in randomized clinical trials. OBJECTIVES: To determine the use and predictors of early invasive management strategies (cardiac catheterization <48 hours following presentation) in high-risk patients with NSTE ACS and to examine the association of early invasive management with mortality. DESIGN, SETTING, AND PATIENTS: The CRUSADE (Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes With Early Implementation of the ACC/AHA Guidelines) Quality Improvement Initiative evaluated care patterns and outcomes for 17,926 high-risk NSTE ACS patients (positive cardiac markers and/or ischemic electrocardiographic changes) based on ACC/AHA guidelines recommendations at 248 US hospitals with catheterization and revascularization facilities between March 2000 and September 2002. MAIN OUTCOME MEASURES: Use of early invasive management within 48 hours of presentation, predictors of early invasive management, and in-hospital mortality. Results Of the 17,926 patients analyzed, 8037 (44.8%) underwent early cardiac catheterization less than 48 hours following presentation. Predictors of early invasive management included cardiology care, younger age, lack of prior or current congestive heart failure, lack of renal insufficiency, ischemic electrocardiographic changes, positive cardiac markers, white race, and male sex. Patients treated with early invasive management were more likely to be treated with medications and interventions recommended by the ACC/AHA guidelines and had a lower risk of in-hospital mortality after adjusting for differences in clinical characteristics and after comparing propensity-matched pairs (2.5% vs 3.7%, P<.001). Conclusions An early invasive management strategy is not utilized in the majority of high-risk patients with NSTE ACS. This strategy appears to be reserved for patients without significant comorbidities and those cared for by cardiologists and is associated with a lower risk of in-hospital mortality.

Aged↗
PubMed2004

Impact of mild or moderate chronic kidney disease on the frequency of restenosis: results from the PRESTO trial.

OBJECTIVES: The goal of this study was to determine if restenosis is increased in mild and moderate chronic kidney disease (CKD) patients after percutaneous coronary intervention (PCI). BACKGROUND: Mortality is increased in CKD after PCI. Restenosis may contribute to increased late mortality. METHODS: We analyzed 11,187 patients with a creatinine <1.8 mg/dl from the Prevention of REStenosis with Tranilast and its Outcomes (PRESTO) trial, grouped by estimated creatinine clearance (CrCl) (<60, 60 to 89, >89 ml/min). The Cox proportional hazards models investigated the association between CrCl group and death, myocardial infarction, and target vessel revascularization (TVR). Generalized estimating equation regression models determined the association between CrCl group and lesion-specific restenosis. RESULTS: At 30 days, there was no difference in myocardial infarction, death, or TVR between the CrCl groups. At nine months, mortality was higher in the lowest CrCl group (2.2%, 1.2%, 0.8%; p < 0.001), which was no longer significant after adjusting for confounding variables. Myocardial infarction and TVR were not different between the groups. In patients undergoing protocol follow-up angiography, restenosis (>/=50%) was not increased with CKD (32%, 32%, 37%; p = 0.02). CONCLUSIONS: Mortality nine months after PCI is mildly increased in mild or moderate CKD patients. However, restenosis is not and does not account for the increased mortality.

Aged↗
PubMed2004

Absence of interaction between atorvastatin or other statins and clopidogrel: results from the interaction study.

BACKGROUND: Some, but not all, post hoc analyses have suggested that the antiplatelet effects of clopidogrel are inhibited by atorvastatin. We sought to address this issue prospectively by performing serial measurements of 19 platelet characteristics using conventional aggregometry, rapid analyzers, and flow cytometry. METHODS: The Interaction of Atorvastatin and Clopidogrel Study (Interaction Study) was designed for patients undergoing coronary stenting. All patients (n = 75) received 325 mg of aspirin daily for at least 1 week and 300 mg of clopidogrel immediately prior to stent implantation. They had been taking atorvastatin (n = 25), any other statin (n = 25), or no statin (n = 25) for at least 30 days prior to stenting. The main outcome measure was comparison of platelet biomarkers 4 and 24 hours after clopidogrel administration between study groups. RESULTS: At baseline, patients from both statin groups exhibited diminished platelet aggregation and reduced platelet expression of G-protein-coupled protease-activated thrombin receptor (PAR)-1. There were no significant differences in measured platelet characteristics among the study groups 4 and 24 hours after clopidogrel intake, with the exception of a lower collagen-induced aggregation at 24 hours and a constantly diminished expression of PAR-1 in patients treated with any statin. CONCLUSIONS: Statins in general, and atorvastatin in particular, do not affect the ability of clopidogrel to inhibit platelet function in patients undergoing coronary stenting. These prospective data also suggest that statins may inhibit platelets directly via yet unknown mechanism(s) possibly related to the regulation of the PAR-1 thrombin receptors.

Aged↗
PubMed2004

Comparison of long-term usefulness of clopidogrel therapy after the first percutaneous coronary intervention or coronary artery bypass grafting versus that after the second or repeat intervention.

Patients in the Clopidogrel for the Reduction of Events During Observation trial were subgrouped according to whether they underwent index percutaneous coronary artery revascularization procedures only or this procedure plus subsequent percutaneous or surgical revascularization procedures during 1-year follow-up. The relative risk reduction in ischemic events associated with up-front and long-term clopidogrel compared with placebo was 2-fold greater in patients who required repeat revascularization procedures compared with those who did not (42.4% vs 21.7%).

Aged↗
PubMed2004

Independent association between plasma leptin and C-reactive protein in healthy humans.

BACKGROUND: C-reactive protein (CRP) is synthesized from the liver and is regulated by cytokines, especially interleukin-6. Leptin, the adipocyte-derived protein product of the ob gene, is related to amount of body fat. The long form of the leptin receptor resembles cytokine receptors, which include the interleukin-6 receptor. Both leptin and CRP may be increased in women, in obesity, and in inflammation, and both have been linked to cardiovascular pathophysiological processes and increased cardiovascular risk. We tested the hypothesis that leptin is associated with CRP levels independently of the influences of gender, body mass index (BMI), waist-to-hip ratio, and other variables. METHODS AND RESULTS: We studied 100 healthy volunteers (48 men, and 52 women). For all subjects, leptin was independently associated with CRP after adjustment for age, gender, BMI, waist-to-hip ratio, smoking, and alcohol consumption (F=12.39, P=0.0007). There was a strong and significant positive relationship between leptin and CRP in both women (R=0.61, P<0.0001) and men (R=0.55, P<0.0001) considered separately. The association between leptin and CRP was significant even after adjustment for age, BMI, waist-to-hip ratio, smoking, and alcohol consumption in women (F=7.13, P=0.01) and men (F=5.69, P=0.02). When only subjects with BMI <25 kg/m2 were considered (n=47), CRP was not linked to BMI (R=0.02, P=0.96), but a significant association between leptin and CRP was still evident (R=0.55, P<0.0001). CONCLUSIONS: Leptin and CRP levels are independently associated in normal humans, providing further evidence linking metabolic and inflammatory cardiovascular disease mechanisms.

Adult↗
PubMed2004

Feasibility of endovascular cooling as an adjunct to primary percutaneous coronary intervention (results of the LOWTEMP pilot study).

In a nonrandomized feasibility study of therapeutic hypothermia in acute myocardial infarction, 18 patients were treated with endovascular cooling (Alsius, Irvine, California) as adjunctive therapy to primary percutaneous coronary intervention to assess measures of infarct size (area under the curve creatinine kinase-MB and technetium-99m single-photon emission computed tomography sestamibi) and the quality of myocardial perfusion (continuous ST-segment monitoring). Periprocedural endovascular cooling successfully decreased core body temperature (median 33.5 degrees C) and was well tolerated, which supports the evaluation of adjunctive hypothermia in pivotal trials to limit infarct size and decrease reperfusion injury.

Angioplasty, Balloon, Coronary↗
PubMed2004

A clinical trial of abciximab in elective percutaneous coronary intervention after pretreatment with clopidogrel.

BACKGROUND: Whether the glycoprotein IIb/IIIa inhibitor abciximab is beneficial in patients undergoing elective percutaneous coronary intervention after pretreatment with clopidogrel is unknown. METHODS: We enrolled 2159 patients with coronary artery disease who underwent a percutaneous coronary intervention: 1079 patients were randomly assigned in a double-blind manner to receive abciximab and 1080 patients to receive placebo. All patients were pretreated with a 600-mg dose of clopidogrel at least two hours before the procedure. The primary end point of the trial was the composite of death, myocardial infarction, and urgent target-vessel revascularization within 30 days after randomization. RESULTS: The incidence of the primary end point was 4 percent (45 patients) in the abciximab group, as compared with 4 percent (43 patients) in the placebo group (relative risk, 1.05; 95 percent confidence interval, 0.69 to 1.59; P=0.82). Most adverse events were myocardial infarctions: the incidence was 4 percent (40 patients) in the abciximab group and 4 percent (41 patients) in the placebo group (P=0.91). Twelve patients (1 percent) in the abciximab group and eight patients (1 percent) in the placebo group had major bleeding complications (P=0.37). Profound thrombocytopenia occurred in 10 patients (1 percent) in the abciximab group but in none in the placebo group (P=0.002). CONCLUSIONS: Our data suggest that in patients at low-to-intermediate risk who undergo elective percutaneous coronary intervention after pretreatment with a high loading dose of clopidogrel, abciximab is associated with no clinically measurable benefit within the first 30 days.

Abciximab↗