# Methods for improved bileaflet aortic valve detection prior to transcatheter aortic valve replacement

## TL;DR

This paper shows that bileaflet aortic valves are often misdiagnosed before TAVR, and using specific CT scan measurements can improve detection and patient outcomes.

## Contribution

The study introduces commissural angle and height comparison as methods to improve bileaflet valve detection in TAVR patients.

## Key findings

- Bileaflet valves were misdiagnosed in 80% of pre-TAVR CTA reports.
- A commissural angle threshold of 141.1 degrees had 73% sensitivity and 86% specificity for identifying bileaflet valves.
- Bileaflet patients had a 38% PPI rate compared to 19% in trileaflet patients.

## Abstract

Bileaflet aortic valve prevalence in transcatheter aortic valve replacement (TAVR) patients is poorly defined. We evaluated a TAVR cohort to determine the bileaflet aortic valve prevalence and understand features which may improve detection. In addition, we related valvar morphology to the occurrence of permanent pacemaker implantation (PPI) following TAVR.

Aortic valvar morphology diagnosis was recorded from the pre-procedural cardiac CTA reports prior to TAVR. Commissural angles, comparison of commissural heights, and dynamic visual inspection of the aortic valve were subsequently evaluated on pre-procedural cardiac CTA by an expert cardiac anatomist and imager, methods previously validated in a surgical cohort, to determine aortic valvar morphology and compared to the historical diagnosis. Relationships between valvar morphological characteristics with the need for PPM within 30-days post-TAVR were determined.

Four-hundred and thirty-three (mean age 81.3 ± 6.6 years, 53.8% female) underwent TAVR [corrected diagnosis: 393 (90.8%) trileaflet vs. 40 (9.2%) bileaflet valves]. Bileaflet valves were historically misdiagnosed in 80% of pre-procedural cardiac CTA reports. Thirty-four (85.0%) had intercoronary leaflet fusion [mean commissural angle = 148.1 (18.3) degrees]. A commissural angle threshold of 141.1 degrees had a sensitivity of 0.73 and specificity of 0.86 for identifying a bileaflet valve. PPI post-TAVR occurred in 38% bileaflet vs. 19% trileaflet patients (p = 0.0114) [unadjusted OR for bileaflet valve requiring PPI = 2.54, 95% CI (1.25–5.01)].

Bileaflet aortic valves are commonly misdiagnosed. Assessment of the commissural angle and comparison of commissural heights may improve CTA-based diagnostic accuracy prior to TAVR. Improved detection may guide improved outcomes in this higher risk population.

Improved bileaflet aortic valve detection can be achieved by cardiac computed tomography prior to transcatheter aortic valve replacement.

Improved bileaflet aortic valve detection can be achieved by cardiac computed tomography prior to transcatheter aortic valve replacement.