Usefulness of Postsystolic Shortening to Diagnose Coronary Artery Disease and Predict Future Cardiovascular Events in Stable Angina Pectoris

Abstract

Postsystolic shortening (PSS) may occur during myocardial ischemia. We aimed to assess the diagnostic and prognostic potential of PSS in patients with suspected stable angina pectoris (SAP). This is a prospective study of patients with suspected SAP (N=293), no prior cardiac history, and normal ejection fraction, who were examined by speckle-tracking echocardiography, coronary angiography, and exercise electrocardiogram. We excluded patients with known heart disease (ischemia, heart failure, valve disease), bundle branch block, pathological Q-waves, and arrhythmias. PSS was assessed using the postsystolic index (PSI), and categorical presence of PSS was defined as PSI≥20% in one myocardial wall. The primary end point was major adverse cardiovascular events (MACEs), a composite of incident heart failure, myocardial infarction, and stroke. The secondary end point was MACE and revascularization (percutaneous coronary intervention/coronary artery bypass graft). A stenosis ≥70% in one or more coronary arteries defined significant coronary artery disease (CAD; n=107). Patients with significant CAD had a higher prevalence of PSS (55% vs 39%; P<.002), and presence of PSS was an independent predictor of significant CAD in multivariable models adjusted for clinical data, exercise test, and echocardiographic measures (odds ratio, 2.45; 95% CI, 1.08-5.60; P=.033). The PSI confirmed this association (odds ratio, 1.71; 95% CI, 1.04-2.82; P=.034 per 1% increase). During median follow-up of 3.5years (interquartile range, 2.7, 4.1) a total of 25 patients (8.5%) experienced MACE and 46 (15.7%) had the secondary end point. Presence of PSS was a predictor of MACE (hazard ratio, 2.57; 95% CI, 1.12-5.95; P=.028), and the association remained significant in adjusted models. Both presence of PSS and PSI were independent predictors of the secondary end point. In patients with suspected SAP, presence of PSS provides independent diagnostic information on significant CAD and offers novel prognostic information regarding risk of future cardiovascular events.