Predictors and incremental prognostic value of left ventricular mechanical dyssynchrony response during stress-gated positron emission tomography in patients with ischemic cardiomyopathy
Journal of Nuclear Cardiology, 06/26/2012
AlJaroudi W et al. – In patients with ischemic cardiomyopathy (ICM), an increase of LVMD during peak gating stress as compared to rest was an independent predictor of all–cause mortality, and had a modest incremental prognostic value. Future studies are needed to validate these findings.Methods
- 489 consecutive patients with ICM, LV ejection fraction (EF) <35% undergoing rest/stress Rb–82 gated PET were evaluated.
- LVMD was determined by phase analysis (SD) from gated rest and peak stress images; LVMDR was defined as stress SD – rest SD, and stratified by tertiles.
- All–cause mortality was the primary outcome.
- Linear regression was performed to determine the predictors of LVMDR, and Cox proportional hazard modeling to assess its independent prognostic value.
- Integrated discrimination improvement (IDI) and net reclassification improvement (NRI) were performed to determine incremental value of abnormal LVMDR.
- Independent predictors of worse LVMD at peak stress were perfusion defect size (PDS) and resting heart rate; while higher resting LVEF, LVEF reserve and rest phase SD were associated with lower LVMDR.
- Over a mean follow–up of 2.0 ± 1.4 years, 123 patients (25%) died.
- After multivariate analysis, LVMDR was an independent predictor of all–cause mortality (HR 1.19[1.01;1.38], per 10° increase, P = .04) and reclassified 18% of patients with IDI 1.4% (P = .02) and NRI 9% (P = .057).