Metabolism of fatty acids in left ventricle myocardium and the efficacy prognosis of cardio-resynchronizing therapy in dilated cardiomyopathy patients

Aim. To study perfusion and metabolism of LV myocardium in patients with dilated cardiomyopathy (DCMP) and to invent on this basement a gamma-specific predictors for cardio-resynchronizing therapy (RT) efficacy. Material and methods. Totally 63 patients with DCMP included (41 male, 22 female) with mean age 55,4±8,3 y. o., having congestive heart failure (CHF) of III–IV NYHA. Before RT all patients underwent scintigraphy of myocardium with 99mÈ (for perfusion assessment) and 123I (for fatty acids metabolism). Before and in 6 months after RT all patients underwent echocardiography to assess intracardiac hemodynamics. Results. In 6 months after RT all patients were divided into two groups: 1) EDV LV decreased by ≥15% (n= 39) — “responders”, and 2) ESV LV decreased <15% (n=24) — “non-responders”. Before RT groups did not significantly differ by pumping function of the ventricle. Significant difference was found by following pre-operational scintigraphic parameters: perfusion defect (PD) (9,22±5,06% and 12,5±4,22%, p<0,01), metabolism defect on earlier pictures (MD) (9,21±5,42% and 11,27±5,39%, p<0,01). The equation of multiple regression was invented, which may prognose the dynamics of end-systolic volume after RT. By the ROC analysis data the main prognostic significance for RT has the size of metabolism defect area and calculated value of end-systolic volume dynamics. The best threshold MD=7,35% and it confirms the efficacy of RT with 77,8% sensitivity and 66,7% specificity. The best threshold value of calculated endsystolic volume dynamics — 34,02 confirms the 87,5% sensitivity and 100% specificity of RT. Conclusion. The data collected during metabolic myocardial gamma-scintigraphy may be used in the complex of methods that allow to predict the efficacy of cardioresynchronizing therapy.