Current treatment trends and long term prognostic value of revascularization in patients with severe ischemia by SPECT-myocardial perfusion imaging

Abstract

Purpose: The best initial therapy for patients (pts) with coronary artery disease (CAD) and severe ischemia by SPECT-MPI is controvertial. Inspired by the ongoing ISCHEMIA Trial, designed to prospectively evaluate optimal medical treatment versus revascularization as the first line therapy in pts with high ischemic burden, we evaluated the current treatment trends, overall mortality and the long term prognostic value of revascularization in patients referred for SPECT-MPI. Methods: We retrospectively evaluated 18,892 pts referred for SPECT-MPI between Jan-2004 and Dec-2008, selecting pts with severe ischemia (SSS>13) and unknown CAD. Overall mortality and revascularization status were obtained by phone. Survival analysis and the prognostic value of revascularization, classical CAD risk factors and left ventricle ejection fraction (LVEF) on mortality were obtained by Kaplan-Meier and Cox multivariate analysis. Results: From 4096 ischemic pts, 715 had SSS>13 but only 255 had no previous known CAD. A mean follow-up time of 4.4 years (SD 1.8) was obtained in 227 (88.4%). Mortality rate was 18.5% (42/227). Management strategy data from 194 pts was obtained. Of these, 123 (63%) underwent percutaneous (70%) or surgical (30%) revascularization, while 71 (37%) were managed conservatively. The overall mortality curves stratified by treatment option were not statistically different (log-rank test p-value = 0.52). The multivariate analysis is presented on the Table. Revascularization did not changed mortality prognosis (HR 1.83; 95% CI 0.72–4.66). View this table: Multivariate analysis Conclusions: Mortality in severely ischemic patients is high. Revascularization was the main treatment option, although only age was predictive of mortality. Based on this limited retrospective analysis, clinical management may be a safe alternative to revascularization for this high risk population, making the ongoing prospective ISCHEMIA Trial essential to guide future first line treatment recommendations.