Thrombolysis In Myocardial Infarction trial, phase III - TIMI 3 Substudies

Description:

Alteplase vs. placebo for clinical outcomes in acute MI.

Hypothesis:

The use of medical resources depends on the natural history and demographics of patients.

Study Design

Study Design:

Patients Screened: 8,676
Patients Enrolled: 3,318
Mean Follow Up: 42 days
Mean Patient Age: 61.5
Female: 49.4
Mean Ejection Fraction: 59.0

Patient Populations:

Episode of exertional pain or chest pain at rest and presumed to be ischemic, lasting five minutes, and occurring within a 96-hour period preceding study entry.

Exclusions:

Persistent ST-segment elevation of 1.0 mm or more for more than 30 minutes
Q-wave MI occurring within 48 hours of the qualifying episode of pain
Pain suggestive of aortic dissection
Pericarditis or pain of noncardiac origin
Constant pain for more than six hours
Inability to cooperate with the protocol

Primary Endpoints:

Incidence of death or myocardial infarction (MI) at 42 days after entry into the prospective study according to race, sex, and age.

Secondary Endpoints:

Recurrent ischemia, and the combined outcomes of death, MI, or recurrent ischemia by 42 days after entry.

Drug/Procedures Used:

t-PA, Revascularization

Principal Findings:

There were 943 blacks and 2375 nonblacks. Compared with nonblacks, blacks were less likely to be treated with intensive anti-ischemic therapy for their qualifying anginal episode and less likely to undergo invasive procedures (risk ratio [RR], 0.65%; 95% confidence interval [CI], 0.58 to 0.72; P<.001). However, of those who underwent angiography (45% of blacks and 61% of nonblacks), blacks had less extensive and severe coronary stenoses than nonblacks. The incidence of death and MI was similar for blacks and nonblacks, but blacks had a lower incidence of recurrent ischemia.

There were 1678 men and 1640 women. Women were less likely than men to receive intensive anti-ischemic therapy and less likely to undergo coronary angiography (RR, 0.71; 95% CI, 0.65 to 0.78; P<. 001). Women had less severe and extensive coronary disease and were less likely to undergo revascularization, yet had a similar risk of experiencing an adverse cardiac event by 6 weeks.

There were 2490 patients aged 75 years or less and 828 patients aged more than 75 years. Elderly patients received less aggressive anti-ischemic therapy and were less likely to undergo coronary angiography than their younger counterparts. Elderly patients had more severe and extensive coronary disease but fewer revascularization procedures than younger patients and experienced a much higher incidence of adverse cardiac events both in hospital and by 6 weeks.

Interpretation:

Among patients presenting with acute ischemic chest pain without persistent ST-segment elevation, blacks appeared to have less severe coronary disease, received revascularization less frequently, and had less recurrent ischemia compared with nonblacks. Women were also found to have less severe coronary disease and were treated less intensely than men, but experienced similar outcomes. Elderly patients had more severe coronary disease than younger patients on coronary angiography, but were more likely to be treated medically, and they experienced far more adverse outcomes. These data suggest that more aggressive strategies should be directed to those patients with the greatest likelihood of adverse outcomes.

References:

1. JAMA 1996;275:1104-12. Final results
2. Am J Cardiol 1995;75:977-81. Predictors of non-Q-wave MI

Keywords: Odds Ratio, Coronary Stenosis, Coronary Angiography, Fibrinolytic Agents, Confidence Intervals, Tissue Plasminogen Activator


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