Role of cardiopulmonary exercise testing in people with heart failure with preserved ejection fraction

Abstract

Background: Heart failure with preserved ejection fraction accounts for approximately half of all heart failure cases, yet it remains difficult to diagnose and poorly characterised at the individual patient level. The defining symptom is exercise intolerance, but standard evaluation relies on resting investigations that underperform in this population. Cardiopulmonary exercise testing measures the integrated physiological response of multiple body systems. The European Society of Cardiology recommended its integration into the HFpEF pathway, but its clinical utility across key domains remains incompletely explored.

Aim: To evaluate the clinical utility of cardiopulmonary exercise testing in people with Heart failure with Preserved Ejection Fraction.

Methods: This cross-sectional study evaluated CPET in 40 patients referred from primary care with suspected HFpEF. Participants underwent individualised ramp cycle ergometry with breath-by-breath gas exchange analysis, alongside echocardiography, NT-proBNP and the Minnesota Living with Heart Failure Questionnaire. CPET reports, SPSSv29 and R software were used for analyses.

Results: Forty participants completed the CPET with no major adverse events. After standard assessment, 72.5% of participants were categorized into intermediate (grey) zone. CPET-derived VO2peak cutoffs reclassified 51.7% of these out of diagnostic uncertainty. Mean VO2peak was 16.11 mL/kg/min, with 55% in Weber Class C. Quality of life scores showed near-complete dissociation from objective exercise capacity. Exercise limitation phenotyping showed 55% participants with multi-domain limitation. Chronotropic incompetence was associated with lower exercise capacity, particularly on beta-blockers. Mean maximal fat oxidation was found to be 0.32 g/min and Fatmax heart rate was 103 bpm. The oxygen uptake efficiency slope remained stable across exercise duration, with OUES at 75% explaining 80% of variance in VO2peak.

Conclusion: CPET proved to be a feasible, safe and clinically informative tool in patients with suspected HFpEF. It resolved diagnostic uncertainty, revealed significant hidden exercise limitations, enabled multi-parameter risk stratification model and provided data for individualized management not achievable through resting investigations alone.

Date of Award	Jun 2026
Original language	English
Sponsors	Department for the Economy
Supervisor	Chris Bleakley (Supervisor), George Kernohan (Supervisor) & Rachel Savage (Supervisor)