Abstract 8087: Association of Left Ventricular Mechanical Dyssynchrony with Outcomes in Ischemic Cardiomyopathy: A Follow-up Study of 587 Patients Undergoing Gated Positron Emission Tomography
Background: We sought to assess the independent contribution of left ventricular (LV) dyssynchrony to prognosis in patients with ischemic cardiomyopathy (ICM).
Methods and Results: Stress/rest Rb-82 gated PET imaging was performed in consecutive patients with ICM and LV ejection fraction (EF) ≤35% (age 66±11 years, 83% men) between 2006 and 2010. Excluding those with CRT, 587 patients were followed for cardiac and all-cause mortality for 1.9±1.4 years. The mean phase dyssynchrony index (standard deviation [SD] 50±21°) was higher than that of a normal group (13±4°, P<0.0001). Of 95 cardiac deaths (16%), 70% were from pump failure, 18% from arrhythmias and 12% from coronary artery disease. Using a SD cut-off of 43° to define dyssynchrony, patients with SD≥43° (n=339) had poorer outcomes than those with SD<43° (cardiac death 19% vs. 12%, p=0.02). However, Cox analysis showed survival to be independently associated with age (HR 1.05 [95%CI 1.03-1.07]), diabetes (1.7[1.14-2.57]), mitral regurgitation (1.39[1.11-1.75]), EF (0.95[0.92-0.98]), and fixed perfusion defect size (PDS) (1.15 [1.05-1.25] per 10% increase), but not SD. Similarly, only age, diabetes, heart failure class, EF and fixed PDS were independently associated with all-cause death. Using nested Cox models, LVEF and fixed PDS added significant information for the prediction of outcome while phase SD did not (Figure 1). Finally, patients with large scar burden (fixed PDS ≥40%) had worse outcome independent of SD (Figure 2).
Conclusion: In patients with ICM, the association of LV dyssynchrony with cardiac death appears to derive from advanced age, diabetes, mitral regurgitation, scar burden and lower LVEF, but not SD.
- © 2011 by American Heart Association, Inc.