Prognostic Utility of the Dicrotic Notch Index in Patients Undergoing Transcatheter Aortic Valve Replacement

The dicrotic notch (DN) on the central aortic pressure waveform reflects aortic valve closure. We aimed to assess the clinical utility of the DN index (DNI) in patients with severe aortic stenosis undergoing transcatheter aortic valve replacement (TAVR).

In this retrospective study, we analyzed 569 patients with aortic stenosis who underwent TAVR between January 2019 and December 2020. Aortic waveform data were used to measure systolic, diastolic, and DN pressures, whereas DNI was calculated as (systolic pressure - DN)/pulse pressure. Pre-TAVR and post-TAVR hemodynamic parameters were compared, and survival analysis was performed using Cox regression with post-TAVR/pre-TAVR DNI ratio as an independent covariate.

Compared to pre-TAVR, DN pressure (92.18 to 95.37, p < 0.001) and DNI (0.45 to 0.58, p < 0.001) significantly increased post TAVR. Higher baseline DNI was predicted by carotid disease, diabetes mellitus, and a higher ejection fraction at baseline. Post-TAVR to pre-TAVR DNI ratio cut point >1.19 is an independent predictor of event-free survival at 2 years. Patients with higher post-DNI/pre-DNI ratio had a significantly lower risk of all-cause mortality in adjusted analyses (hazard ratio: 0.53, 95% confidence interval [CI]: 0.34-0.82).

More than 20% increase in DNI post-TAVR was associated with a lower long-term risk of all-cause mortality. Further studies are needed to understand the determinants of the increase in DNI and if this can be modulated by procedural modifications.