Prognostic Significance of the Residual SYNTAX Score and Ischemic Reduction Detected with Nuclear Cardiology for Prediction of Major Cardiac Events after Revascularization

OBJECTIVE: There is no report on the risk stratification of major cardiac events (MCEs) with a combination of the Synergy between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery (SYNTAX) score and ischemic reduction detected with rest (201)Tl and stress (99m)Tc-tetrofosmin myocardial perfusion single-photon-emission computed tomography (SPECT) after revascularization in Japanese patients with coronary artery disease (CAD). METHODS: This was a retrospective study. The patients were followed up to confirm their prognosis for at least one year. Ischemia was evaluated based on the summed difference scores converted to the percentage of the total myocardium Safety Data Sheet (SDS%). The SYNTAX score and SDS% were calculated before and after revascularization. The endpoint was the occurrence of MCEs. PATIENTS: Study subjects were 293 patients who had a ≥75% stenotic lesion detected with coronary angiography following confirmation of ≥5% ischemia with SPECT, underwent revascularization, and thereafter received a re-evaluation with SPECT and coronary angiography. RESULTS: During the follow-up, 25 patients experienced MCEs of cardiac death (n=2), non-fatal myocardial infarction (n=3), and unstable angina pectoris (n=20). A receiver operating characteristic analysis indicated that the best cut-off values of the residual SYNTAX score and ΔSDS% were 12 and 5%, respectively, for the prediction of MCEs. The patients with a low residual SYNTAX score (<12) and high ΔSDS% (≥5%) had the best prognosis, while those with a high residual SYNTAX score (≥12) and low ΔSDS% (<5%) had the worst prognosis. CONCLUSION: The combination of the residual SYNTAX score and ischemic reduction detected with nuclear cardiology is useful for predicting MCEs after revascularization.