What is the mortality rate of Non-ST-Elevation Myocardial Infarction (NSTEMI)?

NSTEMI Mortality Rates

NSTEMI mortality varies significantly by timeframe and risk profile, with in-hospital mortality ranging from 1.0-3.6%, 30-day mortality from 1.5-4.9%, 6-month mortality around 7-12%, and 1-year mortality from 2.2-3.9%, with higher rates observed in lower-income countries and patients with multiple comorbidities. 1, 2

Short-Term Mortality (In-Hospital and 30-Day)

• In-hospital mortality for NSTEMI patients ranges from 1.0% in high-income countries to 3.6% in low to lower-middle-income countries, demonstrating a clear inverse economic gradient 2
• A recent U.S. registry study reported in-hospital NSTEMI mortality of 1.6%, which was lower than STEMI (4.4%) but higher than unstable angina (0%) 3
• 30-day mortality ranges from 1.5% in high-income countries to 4.9% in low to lower-middle-income countries 2

Medium-Term Mortality (6 Months to 1 Year)

The landmark trials provide consistent mortality data for NSTEMI patients:

• In FRISC-II, the 1-year mortality rate was 2.2% with invasive strategy versus 3.9% with conservative strategy (p=0.016) 1
• In TACTICS-TIMI 18, the 6-month death or MI rate was 7.3% with invasive strategy versus 9.5% with conservative strategy (p<0.05) 1
• The composite endpoint of death, MI, or rehospitalization at 6 months occurred in 15.9% with invasive strategy versus 19.4% with conservative strategy (p=0.025) 1

Long-Term Mortality (Beyond 1 Year)

• At 5 years, FRISC-II demonstrated mortality benefit with invasive strategy (HR 0.81, p=0.009), though benefit was confined to men, nonsmokers, and patients with 2 or more risk factors 1
• A Korean registry study showed 3-year all-cause mortality of 10.9% for NSTEMI, which was paradoxically higher than STEMI (5.8%) after discharge (HR 0.464,95% CI 0.359-0.600, p<0.001) 4
• 3-year cardiac mortality was 6.6% for NSTEMI versus 3.5% for STEMI (HR 0.474,95% CI 0.344-0.654, p<0.001) 4

Risk Stratification and Mortality Prediction

The TIMI Risk Score provides validated mortality estimates for NSTEMI 1:

• Score 0-1: 4.7% risk of death, MI, or urgent revascularization through 14 days
• Score 2: 8.3%
• Score 3: 13.2%
• Score 4: 19.9%
• Score 5: 25.2%
• Score 6-7: 40.9%

The GRACE Risk Score offers in-hospital mortality predictions ranging from 0.2% (score <80) to 52% (score ≥240) 1

Key Mortality Risk Factors

In NSTEMI specifically, the primary risk factors for mortality include 4:

• Low left ventricular ejection fraction (<40%) - strongest predictor
• No percutaneous coronary intervention performed
• Age ≥65 years
• Low hemoglobin (<12 g/dL)

Important Clinical Caveats

• NSTEMI patients have lower in-hospital mortality than STEMI but higher long-term mortality after discharge, likely due to older age, more comorbidities, and less complete revascularization 4
• Mortality risk is substantially higher in low to lower-middle-income countries (in-hospital: 3.6% vs 1.0%; 30-day: 4.9% vs 1.5%) despite younger patient age, reflecting differences in healthcare access and quality 2
• Contemporary mortality rates have improved dramatically - the 2020 ESC Guidelines report 6-month mortality decreased from 17.2% in 1995 to 6.3% in 2015 (adjusted HR 0.40) 1
• Risk stratification is critical - mortality benefit from invasive strategy is primarily seen in medium- and high-risk patients (troponin >0.01 ng/mL, ST-segment deviation, or TIMI score >3), while low-risk patients show similar outcomes with either strategy 1