Abstract 15112: Viability and Ischemia Continue to Predict Outcomes: A Positron Emission Tomography Study of Patients with LV Dysfunction
Aims The recent STICH trial showed lack of prognostic benefit of revascularization (RVS) of myocardium deemed viable by standard techniques. We evaluated the relationship and prognostic implications of jeopardized myocardium (ischemia, hibernation), LV volumes and LVEF reserve by gated Rb-82/F-18-fluorodeoxyglucose (FDG) positron emission tomography (PET).
Methods: 683 consecutive pts (age 65±12, 77 % men, LVEF 32±12%) with known or suspected coronary disease who underwent gated Rb/FDG PET were evaluated. An automated quantitative method was applied to the PET images to measure the extent of ischemia, hibernation, LV volumes and LVEF reserve. The primary outcome was all cause mortality rate. A propensity score model (ps - including unstable angina, past RVS, medical treatment) was developed to predict RVS within 90 days of PET with ps included as a covariate to account for indication bias. A secondary outcome was the rate of cardiac death among a sub-sample of 437 pts where cause of death could be reliably obtained by matching to death records.
Results: During a mean follow-up of 3.4 years, there were 223 (33%) all-cause deaths and 126 (29%) cardiac deaths. There was an increased risk of all-cause death with an increasing percentage of hibernating myocardium (HR = 1.07; 95%CI, 1.03-1.12; p<0.001) and LV volume (HR = 1.04; 95% CI, 1.03-1.06; p<0.001) as well as a decreasing percentage of LVEF reserve (HR = 0.88; 95% CI, 0.79-0.98; p=0.029). Multivariable results for prognostication were similar for cardiac death. Among pts with ischemia, subsequent RVS was protective against cardiac death (p=0.015) but not significant for all-cause death (p = 0.121). Among pts with hibernation, RVS appears to be protective for cardiac death in pts with higher resting LVEF (LVEF≥ 35%; p = 0.019). The addition of ps did not change results.
Conclusions: An increasing percentage of hibernating myocardium, LV volume and a decreasing percentage of LVEF reserve on Rb/FDG PET are associated with an increase in the risk of all-cause and cardiac death. RVS in pts with ischemia and hibernation with higher resting LVEF on Rb/FDG PET is associated with lower rates of cardiac death.
- © 2011 by American Heart Association, Inc.