Determinants of long-term clinical outcomes in patients with angina but without obstructive coronary artery disease: a systematic review and meta-analysis

Aims The long-term prognosis of angina in patients without obstructive coronary artery disease (CAD) is uncertain. To assess the incidence of long-term adverse outcomes in such patients. Methods and results We searched PubMed, Cochrane Library, the Embase database, and the Clinical Trials Registry for studies published in English until January 2017, assessing the composite primary outcome of all-cause death and non-fatal myocardial infarction using random-effects models to estimate pooled incidences. We identified 54 studies, reporting outcomes in overall 35 039 patients (mean age 56, male/female ratio 0.51, 99 770 person-years) with angina and no obstructive CAD. After a median follow-up of 5 years (interquartile range 3-7 years), the pooled incidence of the primary outcome was 0.98/100 person-years [95% confidence interval (CI) 0.77-1.19%], with considerable heterogeneity among studies (I2 = 91%, P