Trends in hospital treatments, including revascularisation, following acute myocardial infarction, 2003–2010: a multilevel and relative survival analysis for the National Institute for Cardiovascular Outcomes Research (NICOR)

OBJECTIVE: To investigate temporal changes in survival after acute myocardial infarction (AMI) by early invasive strategy. METHODS: Accelerated failure time and 6-month relative survival analyses stratified by thrombolysis or primary percutaneous coronary intervention (PPCI) for ST elevation myocardial infarction (STEMI) and coronary angiography for non-STEMI (NSTEMI) encompassing 583 466 patients across 247 hospitals in England and Wales over hospital admission periods 2003-2004, 2005-2006, 2007-2008 and 2009-2010. RESULTS: Survival improved significantly for STEMI patients who received reperfusion therapy (time ratio (TR) 1.47, 95% CI 1.22 to 2.78) and was stable for those who did not (TR 1.02, 95% CI 0.85 to 1.22). While there were significant improvements in survival for NSTEMI patients who underwent coronary angiography (TR 1.39, 95% CI 1.18 to 1.62), there was a significant decline for those who did not (TR 0.70, 95% CI 0.65 to 0.75). Patients without reperfusion therapy or coronary angiography had a greater number of comorbidities, but the use of secondary prevention medications was comparable with patients who received reperfusion therapy or coronary angiography. There was a significant hospital-level survival effect, with higher crude 6-month mortality in hospitals in the lowest coronary angiography and PPCI quartiles (angiography Q1: 16.4% vs Q4: 12.8%; PPCI Q1: 15.8% vs Q4: 12.4%). CONCLUSIONS: Survival rates after AMI have improved. Whereas survival estimates for STEMI patients who did not receive reperfusion therapy were stable, they worsened for NSTEMI patients not receiving coronary angiography.