Comparison of the survival benefit associated with revascularization compared to medical therapy in patients with ischemic cardiomyopathy and left ventricular dysfunction undergoing [18F]FDG-PET

Objectives In patients with ischemic cardiomyopathy (iCMP) and hibernating myocardium (HM) revascularization (RV) might improve left ventricular (LV) function. Less is known about the influence of the amount of HM in conjunction with a therapy decision (RV vs. medical) on the rate of severe cardiac events during follow-up.

Methods 244 patients (209 male; 64 ± 10 yrs) with iCMP and LV dysfunction were referred for viability testing including myocardial perfusion scintigraphy (MPS) at rest and F-18-FDG PET (PET). The amounts of LV scar tissue and HM were quantified (QPS2008/QPC, Cedars-Sinai; CA, USA). During follow-up severe cardiac events (cardiac death or myocardial infarction) were registered. The subgroups of patients were compared using the Kaplan-Meier survival curves and log-rank tests.

Results Mean follow-up time was 2.8 ± 2.4 years, mean time interval between PET and MPS was 17 days with no RV in between. 135 / 244 patients (55%) were referred to RV after MPS/PET which could be performed successfully in 112 cases according to procedure protocolls (110 PTCA and 25 bypass surgeries). 35 / 244 patients (15%) showed HM ≥ 10% and had successful RV. This subgroup had a significant longer event-free survival compared to those with HM ≥10% which had no RV (82 vs. 57 months; p=0.002). There was no significant difference in event-free survival found between patients with HM ≥ 10% and successful RV and patients with small amounts of HM or without HM independent of therapy.

Conclusions Identification and quantification of HM are crucial for further therapy management in patients with iCMP and LV dysfunction. Subjects with HM ≥ 10% were at highest risk for severe cardiac events, if no successful RV was performed