Prognosis for Acute MI Risk should be estimated via formal clinical risk scores (eg, Thrombosis in Myocardial Infarction [TIMI]) or a combination of the following high-risk features: Recurrent angina / ischemia at rest or during low-level activity Heart failure Worsening mitral regurgitation High-risk stress test result (test stopped in ≤ 5 minutes due to symptoms, marked ECG abnormalities, hypotension, or complex ventricular arrhythmias) Hemodynamic instability Sustained ventricular tachycardia Diabetes mellitus PCI within past 6 months Prior coronary artery bypass grafting (CABG) LV ejection fraction < 0.40 Overall mortality rate prior to the modern era of treatment with fibrinolytics and PCI was about 30%, with 25 to 30% of these patients dying before reaching the hospital (typically due to ventricular fibrillation).