Prognostic Value of Exercise Myocardial Scintigraphy in Patients with Coronary Chronic Total Occlusions

Abstract

To evaluate the prognostic value of exercise myocardial scintigraphy in patients undergoing incomplete revascularization by means of percutaneous coronary intervention (PCI) with at least a residual chronic total occlusion (CTO) left untreated. Of 569 consecutive patients with multivessel disease undergoing myocardial scintigraphy after incomplete revascularization by PCI between March 1997 and December 2004, 126 (79% male, 64+/-10 years) with >or= 1 residual CTO fulfilled the eligibility criteria and entered in the study. Hard events defined as cardiac death and myocardial infarction, soft events defined as incidence of unstable angina and PCI procedures, and their composite were assessed at a median follow-up period of 44 months. Hard events were observed in six patients (4.8%). All of them had severely abnormal perfusion defects detected by myocardial scintigraphy. Soft events occurred in 0 (0%), 10 (7.9%), and 15 (11.9%) patients with normal, mildly abnormal, and severely abnormal perfusion, respectively. In the Kaplan-Meier analysis, the log-rank test was statistically significant across patients stratified by summed stress score either in terms of hard, soft and hard, or soft events. Univariate and multivariate Cox proportional-hazards showed an incremental significant information when the scintigraphic variables were added to clinical, angiographic, left ventricular ejection fraction, and Duke treadmill score, for prediction of the composite of hard and soft cardiac events (P < 0.006). Among patients with a residual CTO left untreated after PCI, myocardial perfusion imaging provides significant independent information concerning the subsequent risk of cardiac events.