Value of peak exercise oxygen consumption combined with b-type natriuretic peptide levels for optimal timing of cardiac transplantation

Background-Peak exercise oxygen consumption (VO2) is widely used to select candidates for heart transplantation (HTx). However, the prognosis of patients with advanced heart failure and peak VO2 of 10 to 14 mL/min per kg in the era of modern medical therapy for heart failure is not fully elucidated. B-type natriuretic peptide (BNP) is a useful prognostic marker in patients with heart failure. Methods and Results-A total of 424 patients undergoing HTx evaluation were classified according to peak VO2 during cardiopulmonary exercise testing (>14, 10-14, and <10 mL/min per kg). Survival after cardiopulmonary exercise testing without HTx or ventricular assist device (VAD) support was compared with survival of 743 de novo HTx recipients. Multivariable analysis revealed that high BNP and low peak VO2 were independently associated with death, HTx, or VAD requirements (hazard ratio, 3.5 and 0.6; 95% CI, 1.24-9.23 and 0.03-0.71; P=0.02 and <0.0001, respectively). VAD-free or HTx-free survival of patients with peak VO2 10 to 14 mL/min per kg was identical to post-HTx survival. When patients with peak VO2 10 to 14 mL/min per kg were dichotomized by a cutoff value of BNP of 506 pg/mL, those with BNP<506 pg/mL was equivalent to post-HTx survival (1 year: 90.8% versus 87.2%; P=0.61), whereas those with BNP=506 showed worse VAD-free or HTx-free survival (1 year: 79.7%; P<0.001 versus post-HTx). Patients with peak VO2 <10 mL/min per kg showed worse survival compared with post-HTx survival, and there was a survival difference between those with BNP=506 and <506 pg/mL (1 year: 77.2% versus 56.1%; P=0.01). Conclusions-Patients with peak VO2 10 to 14 mL/min per kg and low BNP levels have a VAD-free or HTx-free survival similar to post-HTx survival in heart recipients, whereas high BNP levels indicate worse outcome in this group of patients.