Feasibility and accuracy of gated blood pool SPECT equilibrium radionuclide ventriculography for the assessment of left and right ventricular volumes and function in patients with left ventricular assist devices

Abstract

BackgroundLeft ventricular assist devices (LVADs) require serial assessment of right and left ventricular (RV & LV) volumes and function. Because the RV is not assisted, its function is a critical determinant of the hemodynamic and contributes significantly to postoperative morbidity and mortality. We evaluated the feasibility and the accuracy of tomographic-equilibrium radionuclide ventriculography (t-ERV) for the assessment of patients with LVADs. MethodsTwenty-four patients with LVAD underwent t-ERV. Because of the limited acoustic window, transthoracic echocardiography (TTE) was only feasible in 19 patients. Functional evaluation including six-minute walk test (6MWT) and peak oxygen consumption (POC) was performed in 18 patients. Nine patients underwent a cardiac multidetector computed tomography (MDCT). Eight patients underwent a second evaluation by ERV 4.3 ± 1.4 months later. ResultsReliability between t-ERV and MDCT for LV end-diastolic volume, LV end-systolic volume, LV ejection fraction, RV end-diastolic volume, RV end-systolic volume, and RV ejection fraction (RVEF) was 0.900 (P = .001), 0.911 (P = .001), 0.765 (P = .021), 0.728 (P = .042), 0.875 (P = .004), and 0.781 (P = .023), respectively. There was no correlation between t-ERV and RV systolic parameters assessed by TTE. RVEF was correlated with POC (R = 0.521; P = .027). A cut-off value of 40% for RVEF measured by t-ERV could discriminate patients with poor functional status (P = .048 for NYHA stage; P = .016 for 6MWT and P = .007 for POC). Conclusiont-ERV is a simple, reproducible, and an accurate technique for the assessment of RV function in patients with LVADs and warrants consideration in the evaluation and monitoring of symptomatic patients.