Abstract 13262: Impaired Myocardial Perfusion Reserve is Associated With Adverse Cardiovascular Events in Patients With Dilated Cardiomyopathy

IntroductionStress perfusion cardiovascular magnetic resonance (CMR) and PET data suggest the presence of microvascular dysfunction in non-ischaemic dilated cardiomyopathy (DCM) but its impact on clinical outcomes is unknown.HypothesisImpaired global stress myocardial blood flow (MBF) and myocardial perfusion reserve (MPR) are associated with increased risk of adverse cardiovascular (CV) events.MethodsAdenosine stress perfusion CMR was undertaken on consecutive DCM patients. Stress and rest global MBF and MPR were derived using a modified Fermi-constrained deconvolution algorithm and follow-up data was collected. The primary outcome was a composite of CV death, CV hospitalization and major arrhythmic events. Cumulative incidence curves were constructed for the primary endpoint, stratified by the median value for stress MBF and a threshold of 1.5 for MPR, selected due to prognostic significance in other cardiac conditions. Cox proportional hazards modelling was performed, adjusting for age, sex, LVEF and midwall fibrosis.ResultsOf 97 patients (63 men, median age 51 years, median LVEF 43%) followed up for median 1661 days, 17 met the primary endpoint. Stress MBF and MPR increased in line with a rise in LVEF (both p=0.01); there was no trend between rest MBF and LVEF (p=0.77). MBF below median and MPR