Increased Mortality among Patients with Higher Right Ventricular Volumes: Volumetric Analysis of Pre-trans-catheter Aortic Valve Replacement CT Angiography

Lilian Atlan ¹ Eva Maret ³ Zach Rozenbaum ² Haim Shmilovich ² Dotan Cohen ¹ Galit Aviram ¹

¹Radiology, Tel Aviv Medical Center, Tel Aviv Affiliated to the Sackler School of Medicine, Tel Aviv University
²Cardiology, Tel Aviv Medical Center, Tel Aviv Affiliated to the Sackler School of Medicine, Tel Aviv University
³Radiology, Stanford Medical Center, Stanford School of Medicine

Background: Cardiac gated computed tomography angiography (CCTA) is the mandatory pre-interventional imaging planning procedure in patients eligible for trans-catheter valve implantation (TAVR). Automated analysis of the cardiac chambers` volumes including the right ventricle (RV), can be obtained from the CCTA and thus contribute to patient selection.

Objectives: To assess the prognostic implications of increased RV volume using CCTA data among patients undergoing TAVR.

Methods: CCTA of patients who underwent TAVR at 2 medical centers – Stanford University Medical Center (California, USA) and Tel Aviv Medical Center (Israel) – between 2013 and 2016 were analyzed by an automatic 4-chamber volumetric analysis (4CVA) software, and grouped according to their RV volume index, into those with the largest RV (upper 5^th percentile of RV volume index (>120 ml/m²; n=16) versus those within the 95^th percentile lower volumes index (≤120 ml/m²; n=307). Differences in baseline characteristics between the groups were adjusted for with a propensity score. The risk for one year mortality following the TAVR was compared between the two groups.

Results: In total 323 patients were included. There were no major differences in background and demographic characteristics between the study groups. A significantly higher 1-year mortality rate was found for patients with large RV (31.3% vs. 7.5%, p=0.008). After adjustment for clinical characteristics, patients with RV volume index >120 ml/m²were at almost a 5 times higher risk for 1-year mortality compared to patients with smaller RV (HR 4.9, 95% CI 1.8-13.1, p=0.002). The addition of echocardiographic parameters to the propensity score did not eliminate the significance of RV volume index >120 ml/m²as an independent predictor for mortality at 1-year (HR 3.9, 95% CI 1.4-10.6, p=0.009). Of note 68.8% of patients with large RV were considered low-intermediate risk for surgery.

Conclusions: Cardiac volumetric data by CCTA performed for procedural planning may help predict outcome in patients undergoing TAVR.

Lilian Atlan