Heartbeat tracking task performance, an indicator of interoceptive accuracy, is associated with improvement of exercise tolerance in patients undergoing home-based cardiac rehabilitation

Aims

Interoception is the sensing function of physiological conditions and is crucial in self-regulation and decision-making. We examined the association of heartbeat tracking task performance, an indicator of interoceptive accuracy, with the degree of improvement in exercise tolerance in patients undergoing home-based cardiac rehabilitation.

Methods and results

Participants underwent baseline peak oxygen uptake (VO₂) measurements and a heartbeat tracking task. The heartbeat tracking task score varies between 0 and 1, with higher scores indicating a better heartbeat perception. After 6 months of home-based exercise training, peak VO₂ was measured again, and the percentage change (%Δ peak VO₂) relative to the peak VO₂ at baseline was calculated. Univariate regression analysis was performed to examine the association between %Δ peak VO₂ and the heartbeat tracking task score. Multiple regression analysis was performed to determine the predictors of %Δ peak VO₂. Of 120 participants, 100 patients (age 65.9 ± 11.9 years; 86% male) were included. There was a significant positive association between %Δ peak VO₂ and the heartbeat tracking task score at baseline (R ² = 0.236, P < 0.001). In multiple regression analysis, the percentage of measured peak VO₂ to the predicted value (%predicted peak VO₂) (β = -0.248, P = 0.002), exercise adherence (β = 0.364, P < 0.001), and heartbeat tracking task score at baseline (β = 0.372, P < 0.001) were significantly associated with %Δ peak VO₂.

Conclusions

Heartbeat tracking task performance, an indicator of interoceptive accuracy, at baseline is associated with the degree of improvement in exercise tolerance.

Multidisciplinary Cardiac Rehabilitation and Long-Term Prognosis in Patients With Heart Failure

Background:

Exercise-based cardiac rehabilitation (CR) improves health-related quality of life and exercise capacity in patients with heart failure (HF). However, CR efficacy in patients with HF who are elderly, frail, or have HF with preserved ejection fraction remains unclear. We examined whether participation in multidisciplinary outpatient CR is associated with long-term survival and rehospitalization in patients with HF, with subgroup analysis by age, sex, comorbidities, frailty, and HF with preserved ejection fraction.

Methods:

This multicenter retrospective cohort study was performed in patients hospitalized for acute HF at 15 hospitals in Japan, 2007 to 2016. The primary outcome (composite of all-cause mortality and HF rehospitalization after discharge) and secondary outcomes (all-cause mortality and HF rehospitalization) were analyzed in outpatient CR program participants versus nonparticipants.

Results:

Of the 3277 patients, 26% (862) participated in outpatient CR. After propensity matching for potential confounders, 1592 patients were included (n=796 pairs), of which 511 had composite outcomes (223 [14%] all-cause deaths and 392 [25%] HF rehospitalizations, median 2.4-year follow-up). Hazard ratios associated with CR participation were 0.77 (95% CI, 0.65–0.92) for composite outcome, 0.67 (95% CI, 0.51–0.87) for all-cause mortality, and 0.82 (95% CI, 0.67–0.99) for HF-related rehospitalization. CR participation was also associated with numerically lower rates of composite outcome in patients with HF with preserved ejection fraction or frail patients.

Conclusions:

Outpatient CR participation was associated with substantial prognostic benefit in a large HF cohort regardless of age, sex, comorbidities, frailty, and HF with preserved ejection fraction.

Efficacy of Cardiac Rehabilitation in Heart Failure Patients With Low Body Mass Index

BACKGROUND

Low body mass index (BMI) is a relevant prognostic factor for heart failure (HF), but HF patients with low BMI are reported to be at risk of not receiving optimal drug treatment. We sought to evaluate the efficacy of cardiac rehabilitation (CR) in patients with low vs. normal BMI. Methods and Results: We studied 152 consecutive patients (low BMI, n=32; normal BMI, n=119) who participated in a 3-month CR program. Low BMI was defined as <18.5 kg/m²and normal BMI, as 18.5≤BMI<25 kg/m². All patients underwent cardiopulmonary exercise testing and muscle strength testing at the beginning and end of the 3-month CR program. After CR, a significantly greater proportion of HF patients with low BMI had a positive change in peak V̇O₂than in the normal BMI group (91% vs. 70%; P=0.010). Average percent change in peak V̇O₂was significantly greater in patients with low vs. normal BMI (17.1±2.8% vs. 7.8±1.5%; P<0.001). In addition, on multivariable logistic regression, low BMI was an independent predictor of a positive change in peak V̇O₂after CR (OR, 3.97; 95% CI: 1.10-14.31; P=0.035).

CONCLUSIONS

CR has a greater effect in patients with low than normal BMI, and low BMI is an independent predictor of a positive change in peak V̇O₂. Thus, CR should be strongly recommended for HF patients with low BMI.

Circulating Biomarkers in Heart Failure

Biological markers have served for diagnosis, risk stratification and guided therapy of heart failure (HF). Our knowledge regarding abilities of biomarkers to relate to several pathways of HF pathogenesis and reflect clinical worsening or improvement in the disease is steadily expanding. Although there are numerous clinical guidelines, which clearly diagnosis, prevention and evidence-based treatment of HF, a strategy regarding exclusion of HF, as well as risk stratification of HF, nature evolution of disease is not well established and requires more development. The aim of the chapter is to discuss a role of biomarker-based approaches for more accurate diagnosis, in-depth risk stratification and individual targeting in treatment of patients with HF.