Impact of left ventricular dyssynchrony by phase analysis on cardiovascular outcomes in patients with end-stage renal disease

Background. Cardiovascular disease is the leading cause of mortality in patients with end- stage renal disease (ESRD). While left ventricular (LV) perfusion pattern and ejection fraction (EF) are important determinant of outcome, the prognostic importance of LV dyssynchrony, which can also be assessed by gated SPECT myocardial perfusion imaging (MPI), has not been well studied in this population. Methods and Results. The indices of LV mechanical dyssynchrony were measured by automated analysis of gated SPECT MPI in patients with ESRD who were evaluated for transplantation at our institution (2001-2004) and who had coronary angiography within 6 months of the evaluation. All-cause mortality data were prospectively collected and verified against the social security death index database. The study population consisted of 144 ESRD patients aged 53 ± 9 years. 35% were women and 63% had diabetes mellitus. The LVEF was 48 ± 12%. They were followed-up for 41 ± 28 months during which time 55 (38%) died prior to renal transplantation. An abnormal QRS duration was not predictive of worse outcomes (log- rank P = .9). The median phase bandwidth (BW) was 62° (inter-quartile range 47-98°) and standard deviation (SD) was 23° (inter-quartile range 15-35°). Patients with a BW above the median had worse survival (log-rank P = .017) and there was a trend toward worse survival in those with a SD above the median (log-rank P = .096). A 2-year mortality was higher in those with BW ≥ 62° in the entire cohort, and in the subsets of patients with normal LVEF (log-rank P = .001), coronary artery disease by angiography, increased LV mass index, QRS <110 ms, and perfusion defect size <20% of the LV. Conclusions. LV mechanical dyssynchrony by phase analysis is a predictor of mortality in patients with ESRD. It may have a role in risk-stratifying patients and should be incorporated in future studies using gated MPI.