Patients with signs and symptoms suggestive of myocardial infarction and non-obstructive coronary arteries are at increased risk of adverse events. The aim of this study was to investigate the predictive role of renal function in troponin-positive patients with non-obstructive coronary arteries.
A total of 564 troponin-positive patients with non-obstructive coronary arteries at coronary angiography and available baseline creatinine levels were stratified according to baseline renal function (normal/stage 1: estimated glomerular filtration rate [eGFR] >90 ml/min/1.73m, stage 2: 60 to 89 ml/min/1.73m, stage 3: 30 to 59 ml/min/1.73m, and stage 4: <30 ml/min/1.73m). The primary outcome measure was mortality at a median follow-up was 100 [12-380] days.
A total of 73 (12.9%), 195 (34.6%), 231 (41.0%), and 65 (11.5%) patients were in the normal/stage 1, stage 2, stage 3, and stage 4 renal dysfunction groups. With progressive renal impairment, patients were older, more frequently presented with established coronary or peripheral artery disease, and had an increased prevalence of cardiovascular risk factors. Cumulative mortality increased with progressive renal dysfunction (normal/stage 1: 0.0%, stage 2: 3.6%, stage 3: 12.1%, stage 4: 32.3%, log rank p < 0.001). A 10 ml/min/1.73m incremental decrease in eGFR was associated with an adjusted HR for mortality of 1.43 (95% CI 1.20-1.72, p < 0.001).
Renal impairment was associated with mortality in patients presenting with elevated cardiac troponin and non-obstructive coronary arteries. Hence, renal function should be incorporated into the risk stratification of these patients.