Determinants and outcomes of coronary angiography after non-ST-segment elevation myocardial infarction. A cohort study of the Myocardial Ischaemia National Audit Project (MINAP).

OBJECTIVE: To investigate determinants of, and outcomes from, coronary angiography and intervention in patients with non-ST-segment elevation myocardial infarction (NSTEMI).
DESIGN: Observational study.
SETTING: 44 British hospitals with interventional facilities. PATIENTS: 13,489 admissions with NSTEMI; July 2005 to December 2006. MAIN OUTCOME MEASURES: Rate of angiography during index admission; death and readmission to hospital within 180 days.
RESULTS: Significantly lower rates of angiography were seen for women, the elderly, the most deprived and those having cardiac, and most non-cardiac, comorbidities. Performance of angiography, compared with no angiography, was not associated with lower rate of readmission (multiple adjusted hazard ratio (HR) = 0.96, 95% CI 0.74 to 1.24) unless accompanied by coronary intervention (HR = 0.73, 95% CI 0.56 to 0.95). Angiography was associated with reduction in 180-day mortality for survivors of hospitalisation (HR = 0.59, 95% CI 0.49 to 0.72); with greater reduction when followed by an intervention (HR = 0.34, 95% CI 0.28 to 0.42). This mortality benefit after intervention was seen both in women (HR = 0.42, 95% CI 0.29 to 0.60) and men (HR = 0.31, 95% CI 0.24 to 0.41), and across age groups: <65 years (HR = 0.25, 95% CI 0.14 to 0.44), 65-79 years (HR = 0.29, 95% CI 0.22 to 0.39) and > or =80 years (HR = 0.52, 95% CI 0.37 to 0.74). Mortality benefit was not significantly attenuated by the presence of comorbidities.
CONCLUSION: Performance of angiography and coronary intervention after NSTEMI was associated with mortality benefit that persisted in the presence of both cardiac and non-cardiac comorbidities. Mortality benefit was seen across age groups and was similar for both sexes.