The added value of cardiopulmonary exercise testing in the diagnosis of heart failure with preserved ejection fraction

Abstract Background Diagnosing heart failure with preserved ejection fraction (HFpEF) is challenging. Two validated algorithms, the HFA-PEFF and H2FPEF scores, have been proposed to guide our clinical practice. Many patients are categorized into an intermediate probability for HFpEF, representing a diagnostic "gray zone." This necessitates further evaluation, including right heart catheterization (RHC) at rest and possibly during exercise, to confirm or exclude the diagnosis. RHC, while informative, is resource-consuming and requires execution in specialized centers. Cardiopulmonary exercise testing (CPET) may offer a non-invasive and cost-effective alternative for differential dyspnea diagnosis. Purpose To evaluate the role of CPET in the diagnostic algorithm of unexplained dyspnea/suspected HFpEF. Methods This single-center retrospective study analyzed patients with a left ventricular ejection fraction (LVEF) ≥ 50% who underwent CPET for unexplained dyspnea from 2016 to 2020. We assessed HFpEF probability using the H2FPEF score and the HFA-PEFF algorithm. We hypothesized that specific CPET parameters (VO2 peak< 80% of predicted and/or VE/VCO2 slope > 35) might provide complementary information to the HFpEF probability scores. Additionally, we hypothesized that CPET could help identifying HFpEF in patients with intermediate probability in a subcohort of patients who underwent exercise RHC. Results Out of 103 patients, 61 (59%) were categorized as intermediate probability of HFpEF according to the HFA-PEFF score, and 59 (57%) according to the H2FPEF score. CPET results (VO2 peak and VE/VCO2 slope) were not associated with the pre-test probability of HFpEF as defined by either of the two scores. Exercise RHC was performed in 26 (43%) and in 27 (46%) patients with intermediate HFA-PEFF score and intermediate H2FPEF score, respectively. Among these patients with intermediate HFpEF probability, VO2 peak < 80% and/or VE/VCO2 slope > 35 had a good specificity and positive predictive value for HFpEF, as compared with exercise RHC (Table). Conclusions CPET provides complementary information to HFA-PEFF and H2FPEF scores. In particular, our results suggest that CPET may reclassify as HFpEF over 25% of patients with an intermediate HFpEF probability according to either the HFA-PEFF score or the H2FPEF score, potentially obviating the need for RHC. Thus, CPET might be incorporated into the HFpEF diagnostic algorithms.Table