Cardiopulmonary exercise testing as a prognosis-assessing tool in heart failure with preserved ejection fraction.

Aims: Patients with heart failure with preserved ejection fraction represent half of the heart failure patients nowadays, an at least steady trend due to the aging of the population. We investigated whether the parameters obtained from cardiopulmonary exercise testing (CPET) correlated with the prognosis of these patients. This prospective observational cohort study assesses the relationship between the CPET parameters peakVO and VE/VCO slope and the number of heart failure hospitalizations or cardiovascular death of these patients.

Methods And Results: From August 2016 until May 2019, 99 patients from our outpatient unit with newly diagnosed heart failure with preserved ejection fraction underwent CPET. Median follow-up was 30 months [interquartile range, 24-38.5]. We selected peakVO < 14 mL/min/kg and a VE/VCO slope > 34 as threshold values for our primary clinically relevant endpoint, a composite of hospitalization for heart failure or cardiovascular death. Mean age was 75.07 ± 7.31 years, 49% were women, 75% were at NYHA class II and median NTproBNP was 511 pg/mL. Mean peakVO was 15.09 ± 4.75, and mean VE/VCO was 36.05 ± 6.60. During follow-up, there were 207 all-cause hospitalizations, 126 cardiovascular hospitalizations, 58 heart failure hospitalizations and 4 deaths. Over a median follow-up of 30 months, the primary clinically relevant endpoint occurred in 5 of 40 patients (12.5%) with a VE/VCO slope ≤ 34 and in 19 of 59 patients (32.2%) with a VE/VCO slope > 34 [hazard ratio, 2.69; 95% confidence interval (CI), 1.00-7.21; P = 0.04]. On multivariate analysis, VE/VCO slope was independently associated with heart failure hospitalization or cardiovascular death as a terminal event.

Conclusions: In patients with heart failure with preserved ejection fraction, a VE/VCO slope > 34 predicts heart failure hospitalizations and cardiovascular death.