SPECT equilibrium radionuclide ventriculography for the assessment of ventricular volumes and function in patients with left ventricular assist devices

Abstract

Objectives Left ventricular assist devices (LVADs) require serial assessment of right and left ventricular (RV & LV) volumes and function. Transthoracic echocardiography (TTE) is limited by acoustic window and cardiac multidetector computed tomography (MDCT) is considered as the best tool to monitor patients with LVADs. We evaluated the feasibility and the accuracy of tomographic equilibrium radionuclide ventriculography (t-ERV) for the assessment of LV and RV volumes and function in patients with LVADs. Materials and methods Twenty-four patients with LVAD (23 HeartMate II and 1 HeartWare) underwent ERV. Because of limited acoustic window, TTE was only feasible in 19 patients. Functional evaluation including six-minutes walk test (6MWT) and peak oxygen consumption (POC) was performed in 18 patients. Nine patients underwent a cardiac MDCT. Eight patients underwent a second evaluation by ERV 4.3 ± 1.4 months later for inter-scan reliability assessment. Results Reliability 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 = 0.001), 0.911 (P = 0.001), 0.765 (P = 0.021), 0.728 (P = 0.042), 0.875 (P = 0.004) and 0.781 (P = 0.023), respectively. There was no correlation between t-ERV and RV systolic parameters assessed by TTE. RVEF was correlated with POC (R = 0.521; P = 0.027). A cut-off value of 40% for RVEF measured by ERV could discriminate patients with poor functional status (P = 0.048 for NYHA stage; P = 0.016 for 6MWT and P = 0.007 for POC). Intra-, inter-rater and inter-scan reliabilities were over 0.9 for the assessment of LV and RV volumes and function by t-ERV. Conclusions t-ERV is a simple, reproducible and accurate technique for the assessment of RV function in patients with LVADs. Because of its good correlation with functional parameters and good inter-scan reliability, t-ERV warrants consideration in the evaluation and monitoring of symptomatic patients with LVADs.