Ventilatory efficiency measured during sub-maximal cardiopulmonary exercise testing predicts postoperative outcomes...

Cardiopulmonary exercise testing is commonly used to evaluate patients for heart transplantation. We assessed the utility of ventilatory efficiency (VE/VCO₂ ) to predict perioperative outcomes following heart transplantation. We retrospectively reviewed all patients undergoing cardiopulmonary exercise testing prior to heart transplantation at our center. Spearman's coefficient showed a correlation between VE/VCO₂ and ICU free days in the first 30-days post-transplant (R = -.37, p < .01). A V_E /VCO₂ cut-off >35 was associated with significantly lower median ICU-free days (23.0 vs. 27 days; p < .01) and a higher likelihood of postoperative morbidity (OR = 5.64, 95% CI = 1.75-18.16; p < .01). Multiple regression analysis controlling for peak oxygen consumption and right heart catheter parameters showed VE/VCO₂ >35 is independently associated with lower ICU-free days (p < .01) and postoperative morbidity (p = .02). Peak oxygen consumption <15 mL/min/kg was not associated with higher ICU or hospital-free days. VE/VCO₂ >35 independently predicts early postoperative morbidity in patients undergoing heart transplantation.