Effects of a Supervised Training Program on Functional Capacity in Patients With HFpEF and Chronotropic Incompetence

Heart failure with preserved ejection fraction (HFpEF) is a highly prevalent clinical entity that predominantly affects women >60 years old, whose incidence has increased in the last decade and has a complex and multifactorial pathophysiology. Chronotropic incompetence (CrI) has emerged as a crucial mechanism, particularly in patients older than 60 years, and is associated with more significant functional impairment. Supervised training programs in patients with heart failure and reduced ejection fraction and CrI have improved functional capacity and chronotropic response. However, we do not have evidence about the effects of a supervised training program on patients with HFpEF and CrI. This work aims to evaluate the effect of a supervised exercise program for 12 weeks in patients with HFpEF and CrI on peak oxygen consumption (peakVO2) and chronotropic response.

This is a prospective study, blinded for the evaluator, randomized (1:1:1:1) to receive standard management alone or combined with a program of training (aerobic alone or combined with strength exercises) that will be carried out in a single centre. After randomization, patients will be clinically evaluated. The primary endpoint (peakVO2) will be assessed by cardiopulmonary exercise testing (CPET) at 12 weeks. Patients with HFpEF, functional class NYHA II-III, and CrI criteria will be enrolled. A sample size estimation [alfa: 0.05, power: 80%, a 15% loss rate, and at least a delta change of mean peakVO2: +2,4 mL/kg/min (SD±2)] of 80 patients (20 per arm) would be necessary to test our hypothesis.

Inclusion criteria

• Patients diagnosed with heart failure with preserved ejection fraction according to 2021 ESC guidelines for Heart Failure.
• N-terminal pro-B-type natriuretic peptide (NT-proBNP) >125 pg/mL in the last month
• Stable symptomatic heart failure patients (New York Heart Association functional class II-III/IV) during the last month
• Age ≥ 60 years old.
• Blunted heart rate (HR) response during a maximal cardiopulmonary exercise testing (CPET), defined as a chronotropic index <0.62 if previous treatment with Beta-blockers or chronotropic index <0.80 in patients without beta-blockers. Chronotropic index= [HRpeak exercise - HRrest] / [220 - age - HRrest]

Exclusion criteria

• Inability to perform a valid baseline cardiopulmonary exercise test
• Cardiac pacemaker
• Significant primary moderate-to-severe valve disease
• Effort angina or signs of ischemia during CPET
• Primary cardiomyopathies
• Cardiac transplantation
• Any other comorbidity with a life expectancy of less than one year