Purpose: The study aimed to investigate the value of clinical variables and rest gated single-photon emission computed tomography (SPECT) in predicting cardiac deaths in medically treated dilated cardiomyopathy (DCM) patients.
Methods: This is a retrospective study. Fifty-six consecutive hospitalized DCM patients who underwent rest gated SPECT myocardial perfusion imaging were initially recruited. Patients were further excluded for receiving heart transplantation, cardiac resynchronization treatment, and noncardiac death during follow-up. The remaining 48 medically treated DCM patients were selected into the final analysis. Phase analysis of gated SPECT was conducted to identify left ventricular (LV) dyssynchrony. Cardiac death during follow-up was considered as the only endpoint. Univariate and multivariate Cox proportional hazards regression analysis were performed to identify the independent predictors of cardiac death. Kaplan-Meier cumulative survival analysis with stratification was performed, and survival curves were compared by log-rank test.
Results: The mean age was 47.5 ± 15.8 years (range, 15–76 yrs) and 85.4% were men. The mean LV ejection fraction was 22.2 ± 7.7%. During the follow-up period (22.7 ± 5.1 mos), 12 (25.0%) cardiac deaths occurred. Compared to survivors, patients with cardiac death had lower body mass index (BMI, P = 0.010), higher percent of prolonged QRS duration (QRSD, P = 0.043), and severe LV dyssynchrony (P = 0.002). Multivariate Cox analysis demonstrated that severe LV dyssynchrony [hazard ratio = 9.607, 95% confidential interval (95% CI) 2.064–44.713, P = 0.004] and BMI (hazard ratio = 0.851, 95% CI 0.732–0.989, P = 0.036) were predictive of cardiac death.
Conclusion: Left ventricular dyssynchrony assessed by phase analysis of gated SPECT and BMI are predictive of cardiac death in medically treated DCM patients.