Relative survival and excess mortality following primary percutaneous coronary intervention for ST-elevation myocardial infarction.

Background:: High survival rates are commonly reported following primary percutaneous coronary intervention for ST-elevation myocardial infarction, with most contemporary studies reporting overall survival.
Aims:: The aim of this study was to describe survival following primary percutaneous coronary intervention for ST-elevation myocardial infarction corrected for non-cardiovascular deaths by reporting relative survival and investigate clinically significant factors associated with poor long-term outcomes.
Methods and Results:: Using the prospective UK Percutaneous Coronary Intervention registry, primary percutaneous coronary intervention cases ( n=88,188; 2005-2013) were matched to mortality data for the UK populace. Crude five-year relative survival was 87.1% for the patients undergoing primary percutaneous coronary intervention and 94.7% for patients <55 years. Increasing age was associated with excess mortality up to four years following primary percutaneous coronary intervention (56-65 years: excess mortality rate ratio 1.61, 95% confidence interval 1.46-1.79; 66-75 years: 2.49, 2.26-2.75; >75 years: 4.69, 4.27-5.16). After four years, there was no excess mortality for ages 56-65 years (excess mortality rate ratio 1.27, 0.95-1.70), but persisting excess mortality for older groups (66-75 years: excess mortality rate ratio 1.72, 1.30-2.27; >75 years: 1.66, 1.15-2.41). Excess mortality was associated with cardiogenic shock (excess mortality rate ratio 6.10, 5.72-6.50), renal failure (2.52, 2.27-2.81), left main stem stenosis (1.67, 1.54-1.81), diabetes (1.58, 1.47-1.69), previous myocardial infarction (1.52, 1.40-1.65) and female sex (1.33, 1.26-1.41); whereas stent deployment (0.46, 0.42-0.50) especially drug eluting stents (0.27, 0.45-0.55), radial access (0.70, 0.63-0.71) and previous percutaneous coronary intervention (0.67, 0.60-0.75) were protective.
Conclusions:: Following primary percutaneous coronary intervention for ST-elevation myocardial infarction, long-term cardiovascular survival is excellent. Failure to account for non-cardiovascular death may result in an underestimation of the efficacy of primary percutaneous coronary intervention.