The HEART Camp Exercise Intervention Improves Exercise Adherence, Physical Function, and Patient-Reported Outcomes in Adults With Preserved Ejection Fraction Heart Failure

Abstract

Background: Despite exercise being one of few strategies to improve outcomes for individuals with heart failure with preserved ejection fraction (HFpEF), exercise clinical trials in HFpEF are plagued by poor interventional adherence. Over the last 2 decades, our research team has developed, tested, and refined Heart failure Exercise And Resistance Training (HEART) Camp, a multicomponent behavioral intervention to promote adherence to exercise in HF. We evaluated the effects of this intervention designed to promote adherence to exercise in HF focusing on subgroups of participants with HFpEF and heart failure with reduced ejection fraction (HFrEF).

Methods and results: This randomized controlled trial included 204 adults with stable, chronic HF. Of those enrolled, 59 had HFpEF and 145 had HFrEF. We tested adherence to exercise (defined as ≥120 minutes of moderate-intensity [40%-80% of heart rate reserve] exercise per week validated with a heart rate monitor) at 6, 12, and 18 months. We also tested intervention effects on symptoms (Patient-Reported Outcomes Measurement Information System-29 and dyspnea-fatigue index), HF-related health status (Kansas City Cardiomyopathy Questionnaire), and physical function (6-minute walk test). Participants with HFpEF (n = 59) were a mean of 64.6 ± 9.3 years old, 54% male, and 46% non-White with a mean ejection fraction of 55 ± 6%. Participants with HFpEF in the HEART Camp intervention group had significantly greater adherence compared with enhanced usual care at both 12 (43% vs 14%, phi = 0.32, medium effect) and 18 months (56% vs 0%, phi = 0.67, large effect). HEART Camp significantly improved walking distance on the 6-minute walk test (η² = 0.13, large effect) and the Kansas City Cardiomyopathy Questionnaire overall (η² = 0.09, medium effect), clinical summary (η² = 0.16, large effect), and total symptom (η² = 0.14, large effect) scores. In the HFrEF subgroup, only patient-reported anxiety improved significantly in the intervention group.

Conclusions: A multicomponent, behavioral intervention is associated with improvements in long-term adherence to exercise, physical function, and patient-reported outcomes in adults with HFpEF and anxiety in HFrEF. Our results provide a strong rationale for a large HFpEF clinical trial to validate these findings and examine interventional mechanisms and delivery modes that may further promote adherence and improve clinical outcomes in this population.

Clinical trial registration: URL: https://clinicaltrials.gov/. Unique identifier: NCT01658670.

Keywords: Heart failure; adherence; exercise; heart failure with preserved ejection fraction; heart failure with reduced ejection fraction.

Figure 1a.. Longitudinal adherence to exercise in adults with HFpEF from the HEART Camp clinical trial using all available data.

This figure demonstrates adherence for participants that completed data collection at each time point in the HFpEF subgroup. In the HEART Camp group, at 6 months, 9/21 (42%) were adherent to exercise, at 12 months, 9/21 (42%) were adherent, and at 18 months 9/16 (56%) were adherent to exercise. In the EUC group, at 6 months, 6/31 (19%) were adherent to exercise, at 12 months, 4/28 (14%) were adherent, and at 18 months 0/28 (0%) were adherent to exercise. * statistically significant, α=.05

Figure 1b.. Longitudinal adherence to exercise in adults with HFrEF from the HEART Camp clinical trial using all available data.

This figure demonstrates adherence for participants that completed data collection at each time point in the HFrEF subgroup. In the HEART Camp group, at 6 months, 26/73(36%) were adherent to exercise, at 12 months, 28/67 (42%) were adherent, and at 18 months 16/55 (29%) were adherent to exercise. In the EUC group, at 6 months, 24/64 (38%) were adherent to exercise, at 12 months, 21/62 (34%) were adherent, and at 18 months 17/60 (29%) were adherent to exercise. Note: Adherence based on 120 minutes of moderate intensity or above exercise per week EUC = Enhanced usual care – received paid access to exercise facility

Figure 2a.. Kansas City Cardiomyopathy Questionnaire (KCCQ) Overall Summary Score.

This figure shows mean KCCQ overall summary scores in the HFpEF subgroup from baseline to 18 months. ANOVA indicated a statistically significant change by group over time. (F(3,96)=3.4,p=.02)

Figure 2b.. Kansas City Cardiomyopathy Questionnaire (KCCQ) Clinical Summary Score.

This figure shows mean KCCQ clinical summary scores in the HFpEF subgroup from baseline to 18 months. ANOVA indicated a statistically significant change by group over time. (F(3,95)=6.2,p=.01)

Figure 2c.. Kansas City Cardiomyopathy Questionnaire (KCCQ) Clinical Summary Score.

This figure shows mean KCCQ clinical summary scores in the HFpEF subgroup from baseline to 18 months. ANOVA indicated a statistically significant change by group over time. (F(3,95)=6.2,p=.01)