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.

PURPOSE:To evaluate the relationship between the burden of chronic thromboembolic disease quantified via CT pulmonary angiography and pre-operative hemodynamics and post-operative hemodynamic improvement in CTEPH patients undergoing PTE. METHODS:CTEPH patients who underwent pulmonary thromboendarterectomy surgery (PTE) between December 2017 and August 2019 were retrospectively screened for having 1) preoperative CT pulmonary angiogram (CTPAs) with corresponding preoperative vascular annotations, 2) preoperative right heart catheterization, 3) bilateral level 2 surgical disease (defined from surgically resected thromboembolic specimen) and 4) recorded postoperative hemodynamics. Clot burden was quantified in preoperative CTPAs using the Qanadli score, which weights the location and severity of thromboembolic lesions into a per-patient score. Mean pulmonary artery pressure, pulmonary vascular resistance, and total pulmonary resistance were obtained from right heart catheterization preoperatively and then on the day of Swan-Ganz removal in the ICU postoperatively. Linear regression was performed between measured clot burden and hemodynamic variables. Continuous variables are presented as mean ± standard deviation. RESULTS:15 patients (7 females, age: 36 ± 13 years, BMI: 35.0 ± 6.7, preoperative mPAP: 40 ± 13 mmHg) met all inclusion criteria. Clot burden score ranged from 11 to 30, with a mean of 19 ± 6. Level of surgical disease seen on imaging matched surgical findings in 87% and 67% of cases (right and left lungs, respectively). Figure 1 illustrates the significant linear correlations between clot burden and preoperative mPAP (R2= 0.59), PVR (R2 = 0.69) and TPR (R2= 0.58), as well as post PTE improvement in PVR (R2 = 0.48) and TPR (R2 = 0.35). CONCLUSION:Pre-operative CT-based quantitative assessment of the pulmonary vasculature is associated with the hemodynamic severity of CTEPH and surgical improvement in PVR after PTE.