Mean Arterial Pressure, Forward Flow, and Right-Sided Hemodynamics During the First 24 h of Monitoring After...

Early postoperative blood pressure targets after HeartMate 3 implantation are largely extrapolated from older devices and chronic-phase data. We examined associations of mean arterial pressure (MAP) with cardiac output (CO), pulmonary artery pulsatility index (PAPi), and acute kidney injury (AKI).

This retrospective cohort included adults undergoing HeartMate 3 implantation with postoperative catheter/MAP monitoring and preoperative right heart catheterization. Spline mixed-effects models evaluated 25 hourly observations from the first available monitoring record. Renal analyses examined 24-h time-weighted average MAP and percentage of monitored time below mean perfusion pressure (MPP) 60 mmHg.

The analysis set contained 75 patients; adjusted CO/PAPi models included 72 complete-case patients. CO curves had a broad mid-range maximum, but tests did not support nonlinearity (p = 0.067) or a MAP-by-time interaction (p = 0.733). PAPi was generally lower at higher MAP and varied with time (interaction p = 0.002). Additional available-outcome analyses identified AKI in 21/73 patients by 72 h and 24/70 by 7 days; 19 events occurred within 24 h. Per 10-percentage-point increase in time with MPP < 60 mmHg, adjusted odds ratios were 1.25 (95% CI 1.02-1.58), and 1.18 (0.98-1.46), respectively. Estimates attenuated with a preoperative creatinine reference.

MAP was associated with PAPi, whereas the statistical evidence for the observed CO pattern depended on how time was modeled. Renal findings remain exploratory because exposure and AKI frequently overlapped. These observations do not establish an optimal pressure target.