Abstract 14391: Mechanical Dyssynchrony Defined by Phase Analysis from GSPECT: Does it Predict Mortality?

Abstract

Background: Phase analysis from gated single photon emission computed tomography myocardial perfusion imaging (GSPECT MPI) has emerged as an attractive means to assess left ventricular mechanical dyssynchrony. Whether dyssynchrony assessed by GSPECT MPI can identify patients at increased risk of mortality is unknown.

Methods: We identified all patients with angiographically significant coronary disease and a GSPECT MPI in the Duke Databank for Cardiovascular Disease between July 2003 and August 2009. The range of time during which 95% of the left ventricle is initiating contraction (phase bandwidth) and the degree of heterogeneity in the distribution of segmental initiation of mechanical contraction (phase standard deviation (SD)) by GSPECT MPI were measured. To evaluate the relationship between each measure of dyssynchrony and long-term survival, unadjusted and adjusted Cox proportional hazards models were constructed.

Results: A total of 1434 patients were identified.The median age was 64 (interquartile range (IQR) 55-72) years. A majority were male (69.6%), were white (73.8%), and had hypertension (HTN)(76.1%). A minority had chronic obstructive pulmonary disease (COPD) (6.6%), congestive heart failure (CHF) (24.3%), diabetes mellitus (DM)(36.2%), peripheral vascular disease (PVD)(10.5%), prior myocardial infarction (MI)(33.0%), or renal insufficiency (RI)(5.4%). The median duration follow-up was 4.2 (IQR 2.8-6.3) years. A total of 377 deaths were observed. After adjustment for age, sex, race, COPD, DM, HTN, PVD, cerebrovascular disease, prior MI, CHF, RI, and tobacco use, phase bandwidth and phase SD were significantly associated with mortality (Table).

Conclusions: Dyssynchrony measured by GSPECT MPI is a significant predictor of mortality and provides information independent of clinical history.