Cost effectiveness of thrombolytic therapy with tissue plasminogen activator as compared with streptokinase for acute myocardial infarction

BACKGROUND. Patients with acute myocardial infarction who were treated with accelerated tissue plasminogen activator (t-PA) (given over a period of 1 1/2 hours rather than the conventional 3 hours, and with two thirds of the dose given in the first 30 minutes) had a 30-day mortality that was 15 percent lower than that of pati

Sustained ventricular arrhythmias among patients with acute coronary syndromes with no ST-segment elevation: incidence, predictors, and outcomes

BACKGROUND: The prognosis of ventricular arrhythmias among patients with non-ST-elevation acute coronary syndromes is unknown. We studied the incidence, predictors, and outcomes of sustained ventricular arrhythmias in 4 large randomized trials of such patients. METHODS AND RESULTS: We pooled the datasets of the Global Use of Streptokinase and tPA for Occluded Arteries (GUSTO)-IIb, Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrilin Therapy (PURSUIT), Platelet IIb/IIIa Antagonism for the Reduction of Acute Coronary Syndrome Events in a Global Organization Network (PARAGON)-A, and PARAGON-B trials (n=26 416). We identified independent predictors of ventricular fibrillation (VF) and ventricular tachycardia (VT) and compared the 30-day and 6-month mortality rates of patients who did (n=552) and did not (n=25 864) develop these arrhythmias during the index hospitalization. Independent predictors of in-hospital VF included prior hypertension, chronic obstructive pulmonary disease, prior myocardial infarction, and ST-segment changes at presentation. Except for hypertension, these variables also independently predicted in-hospital VT. In Cox proportional-hazards modeling, in-hospital VF and VT were independently associated with 30-day mortality (hazard ratio [HR], 23.2 [95% CI, 18.1 to 29.8] for VF and HR, 7.6 [95% CI, 5.5 to 10.4] for VT) and 6-month mortality (HR, 14.8 [95% CI, 12.1 to 18.3] for VF and HR, 5.0 [95% CI, 3.8 to 6.5] for VT). These differences remained significant after excluding patients with heart failure or cardiogenic shock and those who died <24 hours after enrollment. CONCLUSIONS: Despite the use of effective therapies for non-ST-elevation acute coronary syndromes, ventricular arrhythmias in this setting are associated with increased 30-day and 6-month mortality. More effective therapies are needed to improve the survival of patients with these arrhythmias

Selection of thrombolytic therapy for individual patients: development of a clinical model

We developed a logistic regression model with data from the GUSTO-I trial to predict mortality rate differences in individual patients who received accelerated tissue plasminogen activator (TPA) versus streptokinase treatment for acute myocardial infarction. A nomogram was developed from a reduced version of this model that approximated the underlying risk of patients treated with streptokinase, and thus the benefit of TPA. The 30-day mortality rate with accelerated TPA was 0.063 versus 0.073 with streptokinase and subcutaneously administered heparin and 0.074 with streptokinase and intravenously administered heparin. No baseline patient characteristics were significantly associated with a different relative effect of TPA. Older patients and those with anterior infarction, higher Killip classification (except Killip class IV), lower blood pressure, and increased heart rate had the greatest absolute benefit with accelerated TPA. Patients with acute myocardial infarction who had more high-risk characteristics derived a greater absolute benefit from treatment with accelerated TPA versus streptokinase

Link Between the Angiographic Substudy and Mortality Outcomes in Large Randomized Trial of Myocardial Reperfusion

BACKGROUND: The Global Utilization of Streptokinase and TPA for Occluded Coronary Arteries (GUSTO-I) trial was designed to test whether thrombolytic strategies achieving more complete, early, sustained coronary artery patency would lead to further reductions in mortality in patients with acute myocardial infarction. An angiographic substudy within GUSTO-I provided a unique opportunity to examine the relation between mortality and degrees of patency among the regimens. METHODS AND RESULTS: Four thrombolytic strategies were compared in 41,021 patients in GUSTO-I: streptokinase with subcutaneous or intravenous heparin, accelerated tissue plasminogen activator (TPA) with intravenous heparin, and combination streptokinase plus TPA with intravenous heparin. Accelerated TPA was associated with lower 30-day mortality (6.3%) than the other strategies (7.2%, 7.4%, and 7.0%, respectively). Among the 1210 patients in the angiographic substudy randomized to angiography 90 minutes after starting treatment, there was improved patency, particularly Thrombolysis in Myocardial Infarction (TIMI) grade 3 flow, with accelerated TPA over the other regimens (P < .0001). Coronary artery perfusion (TIMI grade 3) at 90 minutes was also a significant predictor of 30-day survival (P < .01). To determine whether differences in mortality among the four strategies matched differences in 90-minute patency, a model was developed for predicting mortality differences in the main trial from the angiographic substudy. The model assumed that any differences in treatment effects on 30-day mortality were mediated through differences in 90-minute patency for the four treatments. The predicted rates were then compared with observed mortality rates of the remaining patients in the main trial for each treatment group. The predicted and observed 30-day mortality rates of the four treatments were streptokinase with subcutan