The impact of coronary atherosclerotic burden on prognosis and presentation of patients with coronary artery disease (CAD) is unknown. We investigated the association of coronary atherosclerotic burden with clinical outcome and presentation as unstable angina in patients with CAD.

This study included 10,647 patients with stable (n = 8,149) and unstable (n = 2,498) CAD who underwent percutaneous coronary intervention (PCI). Coronary atherosclerotic burden was assessed by Gensini score. The primary outcome analysis was 1-year mortality.

Patients were divided into groups according to quartiles of Gensini score: <13 (first quartile; n = 2,650 patients), 13 to <25 (second quartile; n = 2,611 patients), 25 to <53 (third quartile; n = 2,721 patients) and ≥53 (fourth quartile; n = 2,665 patients). There were 295 deaths during follow-up: 41 deaths in the first quartile, 42 deaths in the second quartile, 83 deaths in the third quartile and 129 deaths in the fourth quartile of Gensini score (Kaplan–Meier estimates of 1-year mortality 1.6, 1.7, 3.1 and 5.0 %, respectively; adjusted hazards ratio [HR] = 1.08, 95 % confidence interval [CI] 1.02–1.14, P = 0.007 for each 20-point increase in Gensini score). Gensini score was an independent correlate of presentation as unstable angina (adjusted odds ratio [OR] = 1.07, 95 % CI 1.05–1.10, P < 0.001, for each 20-point increase in the score). Coronary stenoses with ≥75 % of lumen obstruction mediated almost all the increased risk related to the atherosclerotic burden for presentation as unstable CAD (adjusted OR = 1.08, 95 % CI 1.05–1.12, P < 0.001).

In patients with CAD, coronary atherosclerotic burden is independently associated with increased risk of 1-year mortality and presentation as unstable angina.