Detection of regional low myocardial perfusion helps predict a response to cardiac resynchronization therapy in patients with non-ischemic cardiomyopathy: Results of the Find Index by Nuclear Imaging for Dyssynchrony (FIND) study

BackgroundThe aim of this study was to investigate the use of imaging techniques to predict the response to cardiac resynchronization therapy (CRT) in patients with non-ischemic cardiomyopathy (NICM) by simultaneous assessment of left ventricular (LV) dyssynchrony and myocardial perfusion in a single nuclear scan of the heart.MethodsPatients indicated for CRT device implantation underwent a resting myocardial perfusion assessment with single photon emission computed tomography (MP-SPECT) examination using technetium-99 m methoxyisobutylisonitrile prior to device implantation. CardioGRAF and cardioBull software (FUJIFILM RI Pharma, Tokyo, Japan) were used to analyze the LV mechanical dyssynchrony and myocardial viability, respectively. Patient follow-ups were performed at 6 months after device implantation. CRT response was defined as a ≥10% decrease in the LV end systolic volume.ResultsA total of 43 patients with NICM were analyzed. Using the cutoff points of 6.2 for the dyssynchrony index and 66% for LV myocardial perfusion, the combined indices predicted CRT response with a sensitivity of 77.8% and specificity of 91.2%.ConclusionCombined assessment of MP-SPECT and a measure of LV mechanical dyssynchrony showed good predictive ability in patients with non-ischemic heart failure.