Novel markers of myocardial recovery in patients with left ventricular assist device: A cardiopulmonary exercise test and hemodynamic analysis.

Background: Left ventricular assist device (LVAD)-associated myocardial recovery is possible. Beyond peak O2 consumption (pVO2), parameters obtained from cardiopulmonary exercise testing (CPET), such as post exercise oxygen uptake recovery delay (VO2RD), ventilatory efficiency (VE/VCO2 slope), and pressure-flow slopes from invasive hemodynamics, may offer novel insights in recovery assessment. Methods: We performed a retrospective analysis of 46 LVAD recipients with CPET (2014-2024), of whom 5 had complete recovery and LVAD explant (recovered group). A subset (n = 23) had invasive hemodynamics during CPET. VO2RD thresholds were defined as the time required for VO2 to fall below 12.5%, 25%, and 50% of pVO2 (T12.5%, T25%, T50%). Pressure-flow slopes were derived by regressing pulmonary artery wedge pressure (PAWP) and mean pulmonary artery pressure (PAP) against cardiac output (CO) throughout exercise. Results: Compared to nonrecovered group, recovered patients had higher left ventricular ejection fraction (47% [45-48] vs 19% [16-28], p = 0.001), higher pVO2 (14.0 [13.6-20.6] vs 11.0 [9.9-12.3] ml/kg/min, p = 0.007), shorter VO2RD thresholds (T12.5%: 31.4 ± 11.7 vs 47.7 ± 19.1 s, p = 0.03; T25%: 46.8 ± 7.1 vs 65.3 ± 25 s, p = 0.0038; T50%: 82 ± 10.1 vs 99.6 ± 20.9 s, p = 0.027), lower PAWP/CO (1.1 vs 3.6 mm Hg/liter/min, p = 0.003) and PAP/CO (2.4 vs 4.3 mm Hg/liter/min, p = 0.03) slopes. VE/VCO2 slope components in all exercise phases were similar. Conclusions: VO2RD and pressure-flow slopes were lower in recovered patients, and could be incorporated into a prospective wean protocol assessing for complete myocardial recovery in LVAD-supported patients.