Prognosis for ST-Elevation Myocardial Infarction (STEMI)
The prognosis for STEMI patients has dramatically improved over the past two decades, with 30-day mortality decreasing from 25-30% to 4-6% when timely reperfusion therapy is provided by experienced teams at high-volume centers. 1
Key Prognostic Factors
The prognosis varies substantially based on several critical determinants:
Patient Characteristics
- Age: Patients ≥75 years have significantly higher mortality risk, with in-hospital mortality reaching approximately 30% in those with stage 4-5 chronic kidney disease 1
- Killip class: Higher Killip class (heart failure severity) independently predicts early death 1
- Renal function: Dialysis patients experience 21.3% mortality compared to 11.7% for those with end-stage renal failure not on dialysis 1
- Diabetes mellitus: Independently predicts worse outcomes 1
- Prior infarction: Associated with higher mortality 1
- Cardiac arrest: Dramatically worsens prognosis 1
- Hemodynamic status: Tachycardia, hypotension, and cardiogenic shock are strong predictors of death 1
- Infarct location: Anterior infarction carries worse prognosis than inferior infarction 1
Treatment-Related Factors
Reperfusion therapy is the single most important modifiable prognostic factor. Primary PCI performed within 90 minutes of first medical contact by experienced operators at high-volume centers produces the best outcomes, with significant reductions in death, reinfarction, recurrent ischemia, stroke, and length of stay compared to fibrinolytic therapy 1
- Time to reperfusion: Each 10-minute delay in door-to-needle time for fibrinolysis increases 6-month mortality by 0.30%, while each 10-minute delay in door-to-balloon time for primary PCI increases mortality by 0.18% 2
- Complete ST-segment recovery (>70% resolution): Predicts favorable prognosis across all reperfusion strategies, with event rates (death, reinfarction, stroke) of 7.7-9.8% versus 42.9-50% in patients without ST-segment recovery 3
- Hospital volume: Low-volume centers (<49 primary PCIs per year) have 17% higher 30-day mortality compared to high-volume centers 1
- Operator experience: High-volume operators achieve better outcomes 1
Outcomes by Reperfusion Strategy
Primary PCI versus fibrinolysis: When performed within 90 minutes, primary PCI reduces mortality from 10-15% to 3.4-4.5% at intermediate and high-volume centers 1. However, at low-volume centers, primary PCI mortality (6.2%) is similar to fibrinolytic therapy (5.9%) 1
No reperfusion therapy: Historically, 29-42% of STEMI patients received no reperfusion therapy, with substantially worse outcomes 1. Even in 2006,33% of patients presenting within 12 hours received no reperfusion 1
Risk Stratification Tools
The GRACE risk score provides validated 6-month mortality prediction across the ACS spectrum and should be calculated at admission and repeated throughout hospitalization 1. The TIMI risk score was developed specifically for STEMI patients 1.
Special Population Outcomes
Dialysis patients: Only 45% receive reperfusion therapy despite eligibility, and only 67% receive aspirin at discharge 1. Both fibrinolysis and primary PCI carry higher bleeding rates in severe renal dysfunction 1
Women, elderly, blacks, and Medicaid recipients: Experience longer treatment delays, contributing to worse outcomes 1
Inpatient STEMI: Patients who develop STEMI while hospitalized have much worse outcomes than those presenting from outside the hospital, due to older age, more comorbidities, delayed diagnosis, and infrequent reperfusion therapy use 4
Long-Term Prognosis
Complete ST-segment recovery at 90 minutes predicts lower combined endpoint rates (death, reinfarction, stroke) at follow-up: 7.7-9.8% with complete recovery versus 42.9-50% without recovery 3. Patients treated by cardiologists have significantly reduced in-hospital, 30-day, and 1-year mortality compared to non-cardiologists 1
Critical Caveats
Premature discontinuation of antiplatelet therapy dramatically increases risk of stent thrombosis, myocardial infarction, and death, particularly in the first few weeks after ACS 5
Bleeding complications represent a major prognostic concern, with progressive renal dysfunction being a strong predictor of bleeding with antithrombotic therapy 1. Body weight <60 kg increases bleeding risk and may require dose adjustment 5
Cardiogenic shock: Emergency revascularization within 18 hours of shock onset improves survival in patients <75 years 6