Combination of peak exercise systolic blood pressure and left atrial diameter as a novel non-spirometry prognostic predictor comparable to peak oxygen uptake for heart failure with reduced ejection fraction

Background: Although peak oxygen uptake (pV O2) is a well-established powerful prognostic predictor in heart failure (HF) patients, implementation of cardiopulmonary exercise testing (CPX) is limited by its complex analysis. We aimed to develop a new bivariate predictor obtained without respiratory gas measurement, comparable to pV O2. Methods and Results: We studied 560 consecutive HF patients with ejection fraction (EF) <45% who underwent CPX. During a median follow-up of 49.0 months, the composite of all-cause death or HF hospitalization occurred in 228 patients (40.7%) and all-cause death in 111 (19.8%). pV O2 was the strongest single predictor of the composite outcome (chi-square, 99.3). Among the bivariate non-spirometry parameters, the ratio of systolic blood pressure at peak exercise to left atrial diameter (pSBP/LAD) was the strongest predictor (chi-square, 112.4). Patients with pSBP/LAD <2.8mmHg/mm, compared with those with pSBP/LAD ≥2.8mmHg/mm, had a hazard ratio of 3.84 (95% confidence interval, 2.95–5.04) for the composite outcome and 3.66 (2.50–5.37) for all-cause death. In the subgroup with pV O2 <14mL/kg/min (n=149), where pV O2 had no further predictive value, pSBP was the strongest single predictor, and the predictive power of pSBP/LAD was more enhanced. Conclusions: pSBP/LAD was a new powerful predictor of HF hospitalization and death, comparable to pV O2, in HF with reduced EF. Because of its simplicity and high availability, this index has the potential for more widespread use than pVO2.