Predictive value of coronary artery stenoses and C-reactive protein levels in patients with stable coronary artery disease

Abstract

Introduction and aims Coronary occlusions resulting in acute events often occur at the site of non-severe stenoses. We sought to assess the prognostic value of non-obstructive coronary stenoses and C-reactive protein (CRP) levels in patients with chronic stable angina (CSA). Methods We studied 790 consecutive patients with CSA who underwent routine coronary arteriography. High sensitivity CRP and coronary angiograms were assessed at study entry. Angiographic coronary disease severity was graded using a “vessel score” (number of coronary arteries showing at least 50% reduction in lumen diameter) and extent of disease with an “extension score” (proportion of the coronary artery tree showing angiographically detectable atheroma). Patients were followed up for 1 year. Results Significant left main stem disease was present in 54 patients (6.8%). 368 patients (46.6%) underwent revascularization. 71 patients (9%) had at least one of the events comprised in the combined study end-point (unstable angina, myocardial infarction (AMI) and cardiac death). Patients who suffered cardiac adverse events had a significantly higher vessel score ( n) (2.0 [2.0–3.0] vs. 2.0 [1.0–2.0], P < 0.001), extension score (%) (23.5 [17–34.5] vs. 16.0 [6.0–27.0], P < 0.001) and CRP levels (mg/L) (3.0 [1.8–7.2] vs. 2.3 [1.1–4.7], P = 0.001) compared to patients without events. Age, previous history of AMI, vessel score, extension score and CRP levels were significantly associated with the study end-point. Multivariate analysis showed extension score (OR 5.3 [2.8–10.3] CI 95%; P < 0.001), revascularization (OR 0.26 [0.14–0.48] CI 95%; P < 0.001) and CRP levels (OR 1.9 [1.1–3.2] CI 95%; P = 0.03), but not vessel score ( P = 0.1), to be independent predictors of the combined end-point. Conclusions In patients with CSA, independently of revascularization, extension score and CRP levels predict cardiac adverse events, regardless of the presence or absence of flow limiting coronary lesions.