Biomedical subjects
Publications and source records attributed to R M Califf.
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AIMS: To evaluate the clinical characteristics and long-term outcomes of advanced heart failure patients (NYHA Class IIIb-IV) receiving beta-blocker therapy vs. those patients not receiving beta-blockers at randomization in the FIRST trial, a randomized, double-blind, placebo-controlled trial of epoprostenol vs. usual care in advanced heart failure. METHODS AND RESULTS: The patient population consisted of 471 patients enrolled in FIRST with Class IIIb-IV heart failure, left ventricular ejection fraction (LVEF) of <30%, advanced hemodynamic abnormalities, and standard pharmacologic treatment of ACE-inhibitor, diuretics, and/or digoxin. The study cohort consisted of 448 patients not receiving beta-blockers and 23 patients receiving beta-blockers at randomization for the FIRST trial. Patients in the beta-blocker group had decreased rates of any clinical event (P = 0.03), worsening heart failure (P = 0.001), and death or worsening heart failure (P = 0.0008) than patients not receiving beta-blockers. After adjusting for prognostically important variables, the favorable effect of beta-blockers on worsening heart failure (P = 0.02) and death or worsening heart failure (P = 0.02) persisted. CONCLUSION: Patients with advanced heart failure who receive beta-blocker therapy have a lower rate of hospitalization and are less likely to experience worsening heart failure or death at 6 months than patients who are not treated with beta-blockers. These observational data contribute to the growing body of data demonstrating a favorable effect of beta-blockers on clinical outcomes in heart failure.
AIMS: The reported prevalence of angiotensin-converting enzyme (ACE) inhibitor use in patients with heart failure varies considerably. Recent reports suggest that many patients who could benefit from such therapy are not receiving ACE inhibitors. The Study of Patients Intolerant of Converting Enzyme Inhibitors (SPICE) Registry was established to understand better the demographics, characteristics, and contemporary use of ACE inhibitors in an international registry. METHODS AND RESULTS: Between August 1996 and April 1997, each of 105 study centres from eight countries in North America and Europe was invited to review retrospectively the medical records of 100 consecutive patients with left ventricular ejection fractions </=35%. The median age of the 9580 Registry patients was 66 years, 26% were women, the median ejection fraction was 27%, and the primary aetiology of left ventricular dysfunction was ischaemic (63%). Eighty percent of patients were receiving ACE inhibitors. The most common reason for non-use of ACE inhibitors was intolerance (9%). CONCLUSION: The SPICE Registry provides a contemporary description of the demographics and management of patients with documented left ventricular systolic dysfunction. The contemporary use of ACE inhibitors (80%) appears to be higher than previously reported and the main reason for non-use is perceived intolerance (9%).
AIMS: Reteplase has been reported to achieve better patency of the infarct artery than alteplase. As infarct artery patency is strongly associated with survival among patients with cardiogenic shock, we postulated that treatment with reteplase would improve outcomes among shock patients. METHODS: We compared 30-day mortality rates among patients in GUSTO-III who either presented with shock or developed shock after enrollment; all patients received either front-loaded alteplase or reteplase (two bolus doses of 10 MU, 30 min apart). RESULTS: Shock occurred in 260 (5.3%) of 4921 patients randomized to alteplase and 560 (5.5%) of 10,138 patients randomized to reteplase. Of these patients, 28 (10.8%) and 55 (9.8%) randomized to alteplase and reteplase, respectively, presented with shock. In-hospital, 35% and 37% of shock patients assigned to alteplase or reteplase, respectively, underwent coronary angiography, with similar rates of percutaneous (approximately 11-13%) or surgical (approximately 2-3%) revascularization procedures subsequently performed. Death within 30 days occurred in 169 (65%) and 353 (63%) shock patients randomized to alteplase and reteplase, respectively (P = 0.59). Of patients presenting with shock, 64% and 58% of patients randomized to alteplase or reteplase died within 30 days (P = 0.59). CONCLUSION: Compared with alteplase, reteplase did not improve outcome among patients who presented with shock or developed shock after receiving thrombolytics. The newer-generation thrombolytic agents remain of limited efficacy in the treatment and prevention of shock.
AIMS: Studies on the glycoprotein IIb-IIIa receptor blocker abciximab in patients undergoing percutaneous coronary intervention consistently show a reduction in procedure-related myocardial infarction. Some such infarcts are characterized by elevated creatine kinase or creatine kinase-MB, without apparent clinical symptoms. The clinical relevance of such 'creatine kinase leaks' has been questioned. Therefore we investigated the relationship between post-procedural creatine kinase-MB elevation and outcome at the 6 month follow-up. METHODS AND RESULTS: Creatine kinase-MB, or total creatine kinase values were analysed in 5025 out of 6156 patients enrolled in the CAPTURE, EPIC and EPILOG studies. A consistent gradual increase in 6 month mortality was observed as creatine kinase-MB or creatine kinase levels increased: 1.1%, 2.1%, 1.8%, 3. 6% and 6.7% for creatine-MB or creatine ratios (relative to upper limit of normal) <1, 1-3, 3-5, 5-10 and >/=10, respectively. Also the incidence of death or (recurrent) myocardial infarction was related to creatine kinase-MB or creatine kinase ratios. Subsequent revascularization was not related to periprocedural myocardial infarction. By multivariable analysis, correcting for clinical and angiographic characteristics, mortality at 6 months was related to the enzyme (creatine kinase, creatine kinase-MB) ratio, a history of heart failure and age. The combined end-point of death and myocardial infarction was also related to these factors, as well as to a history of bypass surgery and unstable angina. CONCLUSION: Modest elevation of cardiac enzymes (creatine kinase-MB, creatine kinase) after percutaneous coronary intervention is associated with an increased risk of mortality and reinfarction during the 6 month follow-up. Measures to reduce such periprocedural infarcts are warranted.
BACKGROUND: Certain characteristics of unstable angina have been associated with worse clinical outcomes after percutaneous revascularization procedures. METHODS AND RESULTS: We compared outcomes of patients with (n = 690) and those without (n = 320) unstable angina in the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT-I) by unstable angina subgroup: rest chest pain, postinfarction chest pain, chest pain with ischemic electrocardiographic changes, chest pain with recent acceleration, and no chest pain. Regression models were constructed to predict in-hospital and 6-month composite end point death, infarction, bypass surgery, percutaneous revascularization, and abrupt closure (in-hospital) or restenosis (6 months) for each subgroup. Only chest pain with electrocardiographic changes predicted the composite in-hospital outcome (24% vs 17% with no chest pain, P =.0374.) This subgroup also had a greater acute gain, more late loss, and more restenosis than patients in the other subgroups. Rest chest pain carried a higher incidence of the composite 6-month outcome (39.9% vs 29% with no chest pain, P =.0472). For all unstable angina categories, atherectomy was associated with worse overall outcomes than angioplasty. CONCLUSIONS: Patients with unstable angina have more complications of percutaneous revascularization than patients without unstable angina, but event rates vary by anginal subgroup. The clinical presentation may help to identify unstable angina patients at particularly high risk for adverse outcomes.
BACKGROUND: Most analyses of complications after percutaneous coronary intervention have been limited to angiographic predictors of abrupt closure. We sought to determine the relation between baseline clinical and angiographic characteristics and clinical ischemic events and whether treatment with the platelet glycoprotein IIb/IIIa receptor antagonist c7E3 reduced ischemic events differentially in patients with distinct lesion morphologic characteristics. In the EPIC trial, a bolus and infusion of c7E3 decreased the 30-day incidence of death, myocardial infarction, and need for revascularization by 35% in 2099 high-risk patients. METHODS: We used logistic regression modeling to determine the relations between these patients' baseline clinical and angiographic characteristics and the composite primary end point. We also constructed multivariable models with interaction terms to assess treatment effect on prespecified, core laboratory-assessed, coronary morphologic characteristics. RESULTS: The most important predictors of a poor outcome were low weight (chi-square = 10.5, P =.001) and preprocedural percent stenosis (chi-square = 15.0, P <.001). History of hypertension, nonwhite race, and peripheral vascular disease were also associated with an increased risk, as were all measures of lesion complexity except calcification and presence of a side branch. The treatment benefit with abciximab was significantly greater with less complex than with more complex lesion morphologic characteristics. CONCLUSIONS: Future risk models should include these baseline characteristics to define the risk for ischemic complications in individual patients, and treatment with abciximab should not be predicated on lesion morphologic findings alone.
Reperfusion with a regimen of thrombolytic therapy, aspirin, and unfractionated heparin is limited by a number of factors. Only 50% to 60% of patients achieve early thrombolysis in myocardial infarction grade-3 flow within 90 minutes with the most effective thrombolytic regimens. Even after initial reperfusion is achieved, transient and permanent reocclusion occurs too often and is associated with high mortality rates. As more older patients are treated, intracranial hemorrhage is becoming more common. Finally, the risk of bleeding and procedural failure has been high in patients who received an acute percutaneous interventional procedure shortly after treatment with thrombolytic therapy. Given the important role of platelets in the thrombotic process and the relatively weak inhibitory effect of aspirin, it is reasonable to seek agents that will provide more profound platelet inhibition. Early studies with full-dose fibrinolytic and glycoprotein IIb/IIIa inhibitors have been promising, but concern about bleeding has hindered this strategy. Several recent trials have evaluated full-dose abciximab with reduced-dose fibrinolytic therapy and have yielded promising results.
Cardiac catheterization for diagnostic angiography and revascularization, if indicated, plays an increasing role in the management of acute coronary syndromes in the absence of ST elevation. The disagreement between those who favor a conservative approach to intervention and those who favor an aggressive approach centers on whether interventions should be routinely performed in all patients. New pharmacotherapies have emerged that reduce the incidence of death and myocardial infarction in this group of patients. At the same time, the success rate of percutaneous revascularizations has been improved by the widespread use of stenting, and a reduction in complications has been achieved with new pharmacologic agents. As therapies are rapidly evolving, it is difficult to extrapolate the results of earlier clinical trials to the most current practices. Until evidence is available comparing optimal medical management with the most successful interventional techniques, the best approach to intervention is likely to remain the subject of discussion.
Acute coronary syndromes and percutaneous coronary interventions share a common pathophysiological mechanism of intimal disruption and platelet aggregation. Glycoprotein (GP) IIb/IIIa receptor antagonists, which interrupt the final common pathway of platelet activation and aggregation, have been shown to have clear clinical benefit as acute therapy. Treatment of 1000 patients with parenteral formulations prevents at least 1 death, 20 deaths or myocardial infarctions (MIs), and 30 deaths, MIs or revascularisation procedures over a 30-day period. These benefits are sustained at 6 months. Clinical trials of oral formulations are underway. The challenges of dose, haemorrhage and thrombocytopenia must be surmounted before oral antagonists can be incorporated into clinical practice. Despite enrolment of thousands of patients in randomised trials of GPIIb/IIIa antagonists, much additional information is needed to refine the use of this therapy in practice. Application of this drug class will advance a new therapeutic standard for ischaemic heart disease.
BACKGROUND: Significant differences are known to exist between the United States and Canada with respect to coronary catheterization and intervention. In a post hoc analysis, it was hypothesized that these differences may have the greatest impact on outcome in patients at risk for recurrent events such as those following myocardial infarction (MI). PATIENTS AND METHODS: The hypothesis was tested in a nonrandomized comparison of the catheterization and revascularization patterns for patients following acute MI in 7029 patients in the United States and 1774 patients in Canada who participated in the Coumadin/Aspirin Reinfarction Study (CARS). CARS tested the effectiveness of low dose warfarin in combination with acetylsalicylic acid (ASA) versus ASA alone in reducing cardiovascular morbidity and mortality. RESULTS: Before study enrollment (median day 7 to 8), 84.5% of the American patients underwent coronary angiography compared with only 7.7% in Canada (P<0.01). CARS patients in the United States underwent significantly more frequent angioplasty during their hospital admission before study enrollment than their Canadian counterparts (55.8% versus 3.0%, respectively, P<0.01), and there was a more frequent use of intravenous heparin among American CARS patients (96% versus 88%, respectively, P<0.01) but less frequent administration of thrombolytic therapy (44% versus 49%, respectively, P<0.01). For follow-up of up to 32 months, American CARS patients had significantly fewer primary events (cardiovascular deaths, nonfatal MI, nonfatal ischemic stroke) than Canadian patients. Cumulative estimate of a primary end point comparing American with Canadian patients was, respectively, 2.0% versus 3.1% at one month, 8.0% versus 11.3% at one year and 11.6% versus 15.0% at two years. Thus, time to the primary event was significantly longer in American patients (P=0.0001). All-cause mortality estimates at 12 months were 2.2% and 4.0%, respectively, for the American and Canadian CARS subgroups. When management for the index MI (ie, angiography and angioplasty) is included in the model, the risk of death for Canadian versus American subgroups of CARS is not statistically different (0.9, 95% CI 0.6 to 1.2, P=0.40). CONCLUSION: Among study participants, American patients experienced a better outcome than Canadian patients, which may be attributable to more aggressive management based on early coronary angiography and angioplasty. However, angioplasty before study enrollment in American patients may have resulted in enrollment of lower risk patients. This selection bias limits the scope of the comparison.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
BACKGROUND: Sustained ventricular tachycardia (VT) and fibrillation (VF) occur in up to 20% of patients with acute myocardial infarction (MI) and have been associated with a poor prognosis. The relationships among the type of arrhythmia (VT versus VF or both), time of VT/VF occurrence, use of thrombolytic agents, and eventual outcome are unclear. METHODS AND RESULTS: In the GUSTO-I study, we examined variables associated with the occurrence of VT/VF and its impact on mortality. Of the 40 895 patients with ventricular arrhythmia data, 4188 (10.2%) had sustained VT, VF, or both. Older age, systemic hypertension, previous MI, Killip class, anterior infarct, and depressed ejection fraction were associated with a higher risk of sustained VT and VF (P<0.001). In-hospital and 30-day mortality rates were higher among patients with sustained VT/VF than among patients without sustained ventricular arrhythmias (P<0.001). Both early (<2 days) and late (>2 days) occurrences of sustained VT and VF were associated with a higher risk of later mortality (P<0. 001). In addition, patients with both VT and VF had worse outcomes than those with either VT or VF alone (P<0.001). Among patients who survived hospitalization, no significant difference was found in 30-day mortality between the VT/VF and no VT/VF groups. However, after 1 year, the mortality rate was significantly higher in the VT alone and VT/VF groups (P<0.0001). CONCLUSIONS: Despite the use of thrombolytic therapy, both early and late occurrences of sustained VT or VF continue to have a negative impact on patient outcome; patients with both VT and VF had the worst outcome; and among patients who survived hospitalization, the 1-year mortality rate was significantly higher in those who experienced VT alone or VT and VF.
BACKGROUND: The baseline cardiac troponin T (cTnT) level strongly predicts short-term mortality in acute coronary syndromes, but the added value of later measures to predict short- and long-term outcome and in the context of baseline clinical characteristics is unclear. METHODS AND RESULTS: Relations between baseline, peak, and 8- and 16-hour (late) cTnT results and outcomes were assessed in 734 patients in a GUSTO-IIa substudy. Proportional-hazards models assessed the prognostic information gained from late cTnT when added to a mortality model containing the baseline cTnT result and clinical factors. At baseline, 260 patients were cTnT-positive (>0.1 ng/mL), 323 became positive later, and 151 remained negative (</=0.1 ng/mL). Mortality at 30 days was 10% in the baseline-positive group, 5% in late-positive patients, and 0% in negative patients. After adjustment for baseline characteristics, any positive cTnT result predicted 30-day mortality (baseline, chi2=8.96, P=0.0113; 8-hour, chi2=6.51, P=0.0107; 16-hour, chi2=8.40, P=0.0038). Both the 8- and the 16-hour results added to the strength of the baseline result (baseline+8-hour, chi2=12.04, P=0.0072; baseline+16-hour, chi2=13.52, P=0.0036). Only age and ST-segment elevation were stronger predictors of 30-day mortality than baseline cTnT; results were similar for prediction of 1-year mortality. Most of the mortality difference between cTnT-positive and -negative patients occurred within the first 30 days. CONCLUSIONS: The cTnT level is a strong, independent predictor of short-term outcome in acute coronary syndromes. The addition of later samples to a baseline level is useful to evaluate the risk of serious cardiac events.
BACKGROUND: Recurrent ischemia after an acute coronary syndrome portends an unfavorable outcome and has major resource-use implications. This issue has not been studied systematically among the spectrum of patients with acute coronary presentations, encompassing those with and without ST-segment elevation. METHODS AND RESULTS: We assessed the 1-year prognosis of the 12 142 patients enrolled in the GUSTO-IIb trial by the presence (n=4125) or absence (n=8001) of ST-segment elevation. This latter group was further categorized into those with baseline myocardial infarction (n=3513) or unstable angina (n=4488). We also assessed the incidence of recurrent ischemia and its impact on outcomes. Recurrent ischemia was significantly rarer in those with ST-segment elevation (23%) than in those without (35%; P<0.001). Mortality at 30 days was greater among patients with ST-segment elevation (6.1% versus 3.8%; P<0.001) but less so at 6 months; by 1 year, mortality did not differ significantly (9.6% versus 8.8%). Patients with non-ST-segment-elevation infarction had higher rates of reinfarction at 6 months (9.8% versus 6.2%) and higher 6-month (8.8% versus 5.0%) and 1-year mortality rates (11.1% versus 7.0%) than such patients who had unstable angina. CONCLUSIONS: Refractory ischemia was associated with an approximate doubling of mortality among patients with ST-segment elevation and a near tripling of risk among those without ST elevation. This study highlights not only the substantial increase in late mortality and reinfarction with non-ST-segment-elevation infarction but also the opportunities for better triage and application of therapeutic strategies for patients with recurrent ischemia.
Data from the 5 large randomized, double-blind, placebo-controlled trials that used glycoprotein IIb/IIIa inhibitors during percutaneous transluminal coronary angioplasty were pooled for a total of 10,691 patients. We found that the use of glycoprotein IIb/IIIa inhibitors in percutaneous coronary interventions significantly decreases the need for unplanned stenting for abrupt closure.