Do patients with angina alone have a more benign prognosis than patients with a history of acute myocardial infarction, revascularisation or both? Findings from a community cohort study.

AIM To compare prognosis for patients with a diagnosis of angina alone to patients postacute myocardial infarction (AMI) and/or revascularisation and/or angina. DESIGN Community-based retrospective cohort study. SETTING A random selection of 37 Irish general practices. PARTICIPANTS 1,609 adults with ischaemic heart disease (IHD) identified in 2000/1. INTERVENTION Medical records searches and postal questionnaires in 2000/1 and 2005/6. OUTCOME MEASURES Primary: all-cause and IHD-related mortality. Secondary: acute myocardial infarction (AMI), cardiac artery bypass grafting (CABG) and percutaneous transluminal coronary angioplasty (PTCA); physical and mental health status as measured by SF36 and SF12; process of care measurements and behavioural risk factor outcomes. RESULTS Compared with patients with previous AMI and/or revascularisation, patients with angina alone had slightly lower risks of all-cause and IHD-related death: however, although hazard ratios of 0.73 (95% CI 0.55 to 0.98) and 0.65 (95% CI 0.44 to 0.98), respectively, were significant at the p<0.05 level, they were not significant at the p<0.01 level currently suggested as appropriate in observational research. Proportional hazards models identified no statistically significant differences in adjusted risks of subsequent AMI, CABG or PTCA between patients with angina-alone and those with other IHD. Over the 4.5-year follow-up, physical functioning was consistently lower among those with angina alone, and the extent to which physical functioning was increasingly impaired was slightly greater. CONCLUSIONS Prognosis to death or cardiac outcomes for patients with angina alone was similar to those with previous AMI and/or revascularisation, while health status was poorer. The clinical importance of angina should not be underestimated in primary care. Further descriptive research is needed among representative community cohorts of people with angina.