Abstract Body (Do not enter title and authors here): Introduction: Right heart failure (RHF) is a significant contributor to morbidity and mortality after left ventricular assist device (LVAD) implantation. Lack of respiratory variation in the right atrial pressure (RAP) waveform, perhaps a marker of RV reserve capacity, has been associated with RHF and worse outcomes in patients with left heart failure and precapillary pulmonary hypertension. It is unknown if RAP respiratory variation may predict early RHF post-LVAD implantation.

Hypothesis: We hypothesized that lack of RAP respiratory variation pre-implant would be predictive of early post-LVAD RHF.

Methods: In this single center retrospective analysis, pre-LVAD right heart catheterizations for 183 patients who underwent HeartMate 3 LVAD implantation between November 2016 and December 2023 were reviewed. RAP and pulmonary artery wedge pressure (PAWP) respiratory variation were independently quantified by two investigators. Lack of RAP respiratory variation was defined as ≤ 2 mmHg between inspiration and expiration. To account for differences in respiratory effort and pulmonary vascular compliance, the difference between PAWP and RAP respiratory variation was assessed. The 2020 Academic Research Consortium definition was used to define early RHF. Groups were compared using Mann-Whitney U test and Fisher’s exact test.

Results: Sixty-two of 183 patients (34%) developed early RHF post-LVAD. RAP was similar between the no RHF and RHF groups (10.4±6.4 vs. 10.5±6.8, p=0.98). There was no significant difference in RAP respiratory variation between the no RHF and RHF groups (3.2±2.4 vs. 3.0±2.0, p= 0.55). There was no difference in RHF rates between those that lacked and maintained RAP respiratory variation (35% vs. 32%, OR = 0.86, 95% CI [0.47, 1.60]). The difference between PAWP and RAP respiratory variation was not significantly different between no RHF and RHF groups (4.3±2.8 vs. 4.7±3.2, p = 0.41).

Conclusion: Despite the prognostic significance in heart failure and precapillary pulmonary hypertension populations, RAP respiratory variation was not associated with post-LVAD RHF in our study. Ongoing efforts are needed to improve prediction of RHF in patients undergoing durable LVAD implantation.