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

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 peakVO₂ and VE/VCO₂ slope and the number of heart failure hospitalizations or cardiovascular death of these patients.

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 peakVO₂ < 14 mL/min/kg and a VE/VCO₂ 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 peakVO₂ was 15.09 ± 4.75, and mean VE/VCO₂ 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/VCO₂ slope ≤ 34 and in 19 of 59 patients (32.2%) with a VE/VCO₂ slope > 34 [hazard ratio, 2.69; 95% confidence interval (CI), 1.00-7.21; P = 0.04]. On multivariate analysis, VE/VCO₂ slope was independently associated with heart failure hospitalization or cardiovascular death as a terminal event.

In patients with heart failure with preserved ejection fraction, a VE/VCO₂ slope > 34 predicts heart failure hospitalizations and cardiovascular death.