Change in Dicrotic Notch Index Predicts Outcomes in Patients Undergoing Transcatheter Edge-to-Edge Repair for Mitral Regurgitation

Abstract

Background

Changes in the dicrotic notch characteristics in the aortic pressure waveform have not been adequately studied with mitral transcatheter edge-to-edge repair (M-TEER). In this study, we sought to determine the changes in the dicrotic notch index (DNI) with M-TEER and identify their significance in determining procedural success.

Methods

We retrospectively analyzed patients undergoing M-TEER between 2019 and 2022 at our institution. DNI ([systolic-dicrotic pressure]/[systolic-diastolic pressure]) was calculated from invasive ascending aortic pressure waveforms. The cut point for change in DNI was determined and used to compare differences in composite clinical outcomes of mortality and heart failure hospitalization. To identify the determinants of change in DNI, variables including post-M-TEER MR and change in forward stroke volume (FSV) were measured.

Results

Of the 145 patients included in the study cohort, DNI significantly increased after M-TEER (0.49 ​± 0.11 to 0.52 ± ​0.11, p < ​0.001). A cut point of 2.71% change in DNI identified higher probability of event-free survival at 1 year. Using this cut point, change in DNI was an independent predictor of event-free survival (hazard ratio: 0.45 [95% CI: 0.21-0.99], p ​= ​0.01). Of the studied variables, change in FSV was the only predictor of change in DNI (hazard ratio: 0.187 [95% CI: 0.072-0.302], p = 0.002) with significant correlation (r = 0.30, p < ​0.001).

Conclusions

DNI increases after M-TEER, and the magnitude of increase in DNI is associated with better clinical outcomes. Further, increase in FSV correlates with increase in DNI. DNI measured during M-TEER procedure provides an additional simple measure of procedural success.