Validation of Exercise Capacity as a Surrogate Endpoint in Exercise-Based Rehabilitation for Heart Failure: A Meta-Analysis of Randomized Controlled Trials.

OBJECTIVES: This study sought to validate exercise capacity (EC) as a surrogate for mortality, hospitalization, and health-related quality of life (HRQOL). BACKGROUND: EC is often used as a primary outcome in exercise-based cardiac rehabilitation (CR) trials of heart failure (HF) via direct cardiorespiratory assessment of maximum oxygen uptake (Vo2peak) or through submaximal tests, such as the 6-min walk test (6MWT). METHODS: After a systematic review, 31 randomized trials of exercise-based CR compared with no exercise control (4,784 HF patients) were included. Outcomes were pooled using random effects meta-analyses, and inverse variance weighted linear regression equations were fitted to estimate the relationship between the CR on EC and all-cause mortality, hospitalization, and HRQOL. Spearman correlation coefficient (ρ), R2 at trial level, and surrogate threshold effect (STE) were calculated. STE represents the intercept of the prediction band of the regression line with null effect on the final outcome. RESULTS: Exercise-based CR is associated with positive effects on EC measured through Vo2peak (+3.10 ml/kg/min; 95% confidence interval [CI]: 2.01 to 4.20) or 6MWT (+41.15 m; 95% CI: 16.68 to 65.63) compared to control. The analyses showed a low level of association between improvements in EC (Vo2peak or 6MWT) and mortality and hospitalization. Moderate levels of correlation between EC with HRQOL were seen (e.g., R2 <52%; |ρ| < 0.72). Estimated STE was an increase of 5 ml/kg/min for Vo2peak and 80 m for 6MWT to predict a significant improvement in HRQOL. CONCLUSIONS: The study results indicate that EC is a poor surrogate endpoint for mortality and hospitalization but has moderate validity as a surrogate for HRQOL. Further research is needed to confirm these findings across other HF interventions.

Patient perceptions of experience with cardiac rehabilitation after isolated heart valve surgery.

BACKGROUND: Little evidence exists on whether cardiac rehabilitation is effective for patients after heart valve surgery. Yet, accepted recommendations for patients with ischaemic heart disease continue to support it. To date, no studies have determined what heart valve surgery patients prefer in a cardiac rehabilitation programme, and none have analysed their experiences with it. AIMS: The purpose of this qualitative analysis was to gain insight into patients' experiences in cardiac rehabilitation, the CopenHeartVR trial. This trial specifically assesses patients undergoing isolated heart valve surgery. METHODS: Semi-structured interviews were conducted with nine patients recruited from the intervention arm of the trial. The intervention consisted of a physical training programme and a psycho-educational intervention. Participants were interviewed three times: 2-3 weeks, 3-4 months and 8-9 months after surgery between April 2013 and October 2014. Data were analysed using qualitative thematic analysis. RESULTS: Participants had diverse needs and preferences. Two overall themes emerged: cardiac rehabilitation played an important role in (i) reducing insecurity and (ii) helping participants to take active personal responsibility for their health. Despite these benefits, participants experienced existential and psychological challenges and musculoskeletal problems. Participants also sought additional advice from healthcare professionals both inside and outside the healthcare system. CONCLUSIONS: Even though the cardiac rehabilitation programme reduced insecurity and helped participants take active personal responsibility for their health, they experienced existential, psychological and physical challenges during recovery. The cardiac rehabilitation programme had several limitations, having implications for designing future programmes.

Availability of, referral to and participation in exercise-based cardiac rehabilitation after heart valve surgery: Results from the national CopenHeart survey.

BACKGROUND: As with ischaemic heart disease, cardiac rehabilitation (CR) is recommended for patients undergoing heart valve surgery; recommendations are based on limited evidence. The organization of CR programmes and factors associated with uptake among patients undergoing heart valve surgery have not been studied. This study investigated CR programmes for these patients and factors associated with referral and participation. DESIGN AND METHODS: We distributed two nationwide surveys: one to 37 hospitals and 98 municipalities and one to 742 consecutive patients undergoing heart valve surgery. Data were linked to nationwide registries. We analysed the provision and content of programmes using descriptive statistics, and factors associated with referral and participation using logistic regression analysis. RESULTS: Coverage of CR programmes for these patients was high, with national programme variation. The overall uptake rate was 52%. Simultaneous CABG was associated with a higher probability of referral to CR (OR 2.02 (95%CI 1.12-3.65)); being unmarried (0.44 (0.27-0.72)) and having TAVI with a lower probability (0.26; 0.13-0.52). The referral pattern varied across administrative regions, with patients in the capital region less likely to be referred (0.22 (0.08-0.57)). Patients with TAVI were less likely to participate (0.29 (0.12-0.70)). CONCLUSIONS: Despite high national programme coverage, only half the patients post heart valve surgery received CR. Both factors identified at provider- and patient-level influenced uptake and included significant regional variation in referral pattern. Further research into the effect and organization of CR post heart valve surgery is needed.