Predictive value of SPECT myocardial perfusion imaging in patients with unrevascularized coronary chronic total occlusion.

Abstract

Data involved the association between myocardial ischaemia and the outcome for unrevascularized coronary chronic total occlusion (CTO) patients were limited. The purpose of this study was to evaluate the predictive value of ischaemia detected by single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) for the adverse events in unrevascularized CTO patients. We further explored whether ischaemia generated from CTO vessel can independently predict the outcome. Patients with at least one unrevascularized CTO on coronary angiography were enrolled in this study. Exercise stress/rest SPECT MPI was performed in all patients. All patients were then followed by telephone interview and reviewing of medical records. Patients with ischaemia experienced significantly higher rate of adverse events than non-ischaemia patients (40.7% vs 7.1%, P = 0.002). Ischaemia demonstrated on MPI [odds ratio (OR) = 7.656; 95% confidence interval (CI) 1.598-36.677; P = 0.011] was an independent predictor for adverse events. Moreover, CTO-ischaemia (OR = 5.466; 95% CI 1.015-29.420; P = 0.048), non-CTO ischaemia (OR = 29.174; 95% CI 3.245-262.322; P = 0.003), mixed-ischaemia (OR = 7.130, 95% CI 1.257-40.445; P = 0.027) were all independent predictors for outcome. Ischaemia demonstrated on MPI, especially CTO-ischaemia were independent predictors for the adverse events. SPECT MPI can aid to identify patients at risk of adverse events, who may benefit from subsequent CTO percutaneous coronary intervention.