Pre-LVAD CT-Derived Measures of RV Size and Function May Be Strong Identifiers of Right Ventricular Failure

Purpose LVADs are a commonly used treatment for patients with end stage heart failure, though these patients are at a high risk of right ventricular failure (RVF) after implantation. ECG-gated, contrast enhanced functional CT provides quantitative volumetric and functional measures that may prove more useful in predicting RVF than traditional measures. Methods Since September 2017, ECG-gated CT scans of the heart were acquired on a Revolution Scanner (GE Healthcare) as part of a work-up in heart failure patients with GFR > 40. For this study, we included patients who received a functional CT scan and went on to receive an LVAD. RVF classification and severity was assessed within 6 months of the implant as per INTERMACs criteria for LVAD patients. Prognostic values for previously published risk scores and common predictors were compared to RV size and function. Area Under the curve (AUC) values, accuracy, sensitivity and specificity were used to compare CT RV EDVI and RVEF to CVP, Creatinine, PAPI, Michigan Score, and CRITT score. Results Of the 62 scanned, 12 received LVADs. Post implantation, 7 patients had RVF (5 moderate, 2 severe). Patients were evaluated for their RV EDVI (131 ± 34 mL/m2), RVEF (30 ± 13%), CVP (9 ± 4 mmHg), Creatinine (1.17 ± 0.25 mg/dL), PAPI (2.74 ± 1.91), Michigan Score (2 ± 2), and CRITT score (0.5 ± 0.7). RV EDVI, RVEF, and PAPI were the strongest predictors (AUC = 0.75, 0.725, 0.714 respectively), with ideal cutoff of 144 ml/m2 for RVEDVI, 27% for RVEF, and 1.88 for PAPI. Creatinine was less predictive (AUC = 0.7), and the Michigan Score, CRITT score, and CVP were not predictive(AUC = 0.575, 0.5, 0.5). Conclusion For this small cohort, functional CT derived parameters had high AUC in predicting RVF in LVAD patients, and may prove useful in future risk assessment.