Post-Exercise Heart Rate Recovery Independently Predicts Clinical Outcome in Patients with Acute Decompensated Heart Failure

Heart Rate Recovery: Up to Date in Heart Failure-A Literature Review

The rising prevalence of cardiovascular disease underscores the growing significance of heart failure (HF). Pathophysiological insights into HF highlight the dysregulation of the autonomic nervous system (ANS), characterized by sympathetic overactivity and diminished vagal tone, impacting cardiovascular function. Heart rate recovery (HRR), a metric measuring the heart's ability to return to its baseline rate post-exertion, plays a crucial role in assessing cardiovascular health. Widely applied across various cardiovascular conditions including HF, coronary artery disease (CAD), and arterial hypertension (HTN), HRR quantifies the difference between peak and recovery heart rates. Given its association with elevated sympathetic tone and exercise, HRR provides valuable insights into the perspective of HF, beyond effort tolerance, reaching toward prognostic and mortality indicators. Incorporating HRR into cardiovascular evaluations enhances our understanding of autonomic regulation in HF, offering potential implications for prognostication and patient management. This review addresses the significance of HRR in HF assessment, analyzing recently conducted studies, and providing a foundation for further research and clinical application.

Early cardiac rehabilitation for acute decompensated heart failure safely improves physical function (PEARL study): a randomized controlled trial

BACKGROUND

Improvements in the Short Physical Performance Battery (SPPB) rather than exercise tolerance reportedly lead to favorable prognosis in elderly patients with acute decompensated heart failure (ADHF). However, about 50% of heart failure shows heart failure with preserved ejection fraction, safe and effective interventions to improve SPPB for these types remain unclear. In addition, although a standard cardiac rehabilitation (CR) program for heart failure is widely used in Japan, whether this is sufficient to improve SPPB in elderly patients with ADHF remains unclear.

AIM

This study was to evaluate whether the addition of multidisciplinary physical interventions to the standard CR program would prove effective for improving SPPB among elderly patients with ADHF regardless types of heart failure.

DESING

Randomized, prospective study.

SETTING

Patients admitted to our hospital due to ADHF in Japan.

POPULATION

Elderly patients with ADHF between March 2019 and March 2020 were randomized to two groups, an Intervention group and a Control group.

METHODS

The Control group performed standard CR. The Intervention group received balance training and resistance training and used a cycling ergometer in addition to the standard CR program. The primary outcome was the improvement in SPPB after CR.

RESULTS

Seventy-five patients with ADHF were divided into the two groups (Intervention group, n=36; Control group, n=39). At baseline, both groups showed low physical performance and a high prevalence of frailty. Intervention size effect was an improvement in SPPB score of +2.2 (+3.7±1.1 vs. +1.5±1.7; p<0.001). Of the 3 components of SPPB, both gait speed and timed repeated chair rise were significantly improved in the Intervention group compared to the Control group, with intervention size effect of +0.76 and +0.94, respectively (p<0.001). Subgroup analysis of heart failure with preserved ejection fraction showed significant improvement in SPPB score in the Intervention group compared to the Control group (p<0.001).No adverse events were observed during the study period.

CONCLUSIONS

A multi-faceted intervention in addition to standard CR improved physical performance among elderly patients with ADHF regardless types of heart failure.

CLINICAL REHABILITATION IMPACT

We believe that use of a cycling ergometer and loadspecific resistance training provide specific CR for patients with ADHF during acute hospitalization and highlight the need for active intervention.

Prognostic Value of Leg Muscle Strength in Acute Heart Failure Syndrome

INTRODUCTION

Leg muscle strength (LMS) may be useful as a frailty index in patients with heart failure. However, LMS, until recently, has been indirectly estimated, and its prognostic value in acute heart failure syndrome (AHFS) is unclear. Therefore, we evaluated the prognostic value of direct LMS assessment and its relationship with proinflammatory mediators in patients with AHFS.

METHODS

We directly measured LMS at predischarge using a dynamometer in 110 prospectively and consecutively enrolled patients with AHFS (75 male; 60 ± 14 yr; mean ejection fraction, 29.9% ± 14.6%). The primary end point was cardiovascular (CV) events, defined as CV mortality, cardiac transplantation, or rehospitalization due to heart failure aggravation. Patients were divided into impaired and preserved LMS groups according to Contal and O'Quigley's method.

RESULTS

CV events occurred in 28 patients (25.5%) (including 5 CV deaths and 6 cardiac transplantations) during follow-up (median, 246 d; range = 11-888 d). Impaired LMS was associated with significantly higher levels of serum monokine induced by gamma interferon and poor clinical outcomes (P < 0.001). Multivariable Cox proportional hazard analysis (controlling for age, sex, body mass index, heart failure type, hemoglobin level, N-terminal pro-b-type natriuretic peptide level, and beta-blocker use) revealed LMS as an independent predictor of CV events (P = 0.017).

CONCLUSION

Impaired LMS, which might be used as a marker of frailty, is associated with increased levels of a proinflammatory chemokine and independently predicts clinical outcomes in patients with AHFS. The direct measurement of LMS is simple and feasible and might have important implications for the risk stratification of patients with AHFS.

Increased frequency of CD4+CD57+ senescent T cells in patients with newly diagnosed acute heart failure: exploring new pathogenic mechanisms with clinical relevance

Recent animal studies showed T cells have a direct pathogenic role in the development of heart failure (HF). However, which subsets of T cells contribute to human HF pathogenesis and progression remains unclear. We characterized immunologic properties of various subsets of T cells and their clinical implications in human HF. Thirty-eight consecutive patients with newly diagnosed acute HF (21 males, mean age 66 ± 16 years) and 38 healthy control subjects (21 males, mean age 62 ± 12 years) were enrolled. We found that pro-inflammatory mediators, including CRP, IL-6 and IP-10 and the frequencies of CD57⁺ T cells in the CD4⁺ T cell population were significantly elevated in patients with acute HF compared to control subjects. A functional analysis of T cells from patients with acute HF revealed that the CD4⁺CD57⁺ T cell population exhibited a higher frequency of IFN-γ- and TNF-α- producing cells compared to the CD4⁺CD57⁻ T cell population. Furthermore, the frequency of CD4⁺CD57⁺ T cells at baseline and its elevation at the six-month follow-up were significantly related with the development of cardiovascular (CV) events, which were defined as CV mortality, cardiac transplantation, or rehospitalization due to HF exacerbation. In conclusion, CD4⁺CD57⁺ senescent T cells showed more inflammatory features and polyfunctionality and were associated with clinical outcome in patients with acute HF. More detailed study for senescent T cells might offer new opportunities for the prevention and treatment of human HF.

The prognostic value of heart rate recovery in patients with coronary artery disease: A systematic review and meta-analysis

BACKGROUND

Routine outpatient care of patients with coronary artery disease (CAD) lacks a simple measure of physical fitness and risk of mortality. Heart rate recovery (HRR) is noninvasive and easily obtainable in outpatient settings. Prior studies have suggested that delayed postexercise HRR in the first minutes is associated with mortality in several types of populations. However, a comprehensive overview of the prognostic value of delayed HRR for time to mortality specifically in CAD patients is not available. The purpose of the current meta-analysis is to evaluate the prognostic value of delayed HRR in CAD patients.

METHODS

We conducted a systematic search in OVID MEDLINE and OVID EMBASE to identify studies reporting on HRR and risk of incident cardiovascular events or mortality in CAD patients. Hazard ratios for delayed versus nondelayed HRR were pooled using random-effects meta-analysis.

RESULTS

Four studies were included, comprising 2,428 CAD patients. The study quality of the included studies was rated moderate (n = 2) to high (n = 2). Delayed HRR was defined by ≤12 to ≤21 beat/min in the recovery period. During follow-up (range 2.0-9.8 years), 151 patients died (6.2% [range 2.5%-19.5%]). Only data on mortality could be pooled. Heterogeneity was limited (I² = 32%; P = .23); pooled unadjusted hazard ratio for mortality, based on 3 studies, was 5.8 (95% CI 3.2-10.4).

CONCLUSIONS

In CAD patients, delayed HRR is significantly associated with all-cause mortality. As exercise testing is performed routinely in CAD patients, HRR can be considered in monitoring exercise; still, further research must investigate the addition of HRR in current risk scores.

Penumbral role of beta blockade on heart rate recovery in heart failure

We would agree that Heart Rate Variability (HRR) is a measure of parasympathetic activity, which may need to be augmented in chronic management of Heart Failure (HF). A viable next step would be the determination of the relative strength of the sympathetic response versus the decrease of parasympathetic tone in HF, while taking into consideration the suppression of the sympathetic nervous system by virtue of Beta Blockade, which constitutes standard therapy.

Relationship Between Post-exercise Heart Rate Recovery and Changing Ratio of Cardiopulmonary Exercise Capacity

Objective

To determine whether heart rate recovery (HRR) following an exercise tolerance test (ETT) is correlated with a changing ratio of peak oxygen consumption (VO₂) and maximal metabolic equivalents (MET_max).

Methods

A total of 60 acute myocardial infarction (AMI) patients who underwent ETT at both assessment points - 3 weeks (T0) after the AMI attack and 3 months after T0 (T1) were included. After achieving a peak workload, the treadmill was stopped with a 5-minute cooldown period, and the patients recovered in a comfortable and relaxed seated position. HRR was defined as the difference between the maximal heart rate (HR_max) and the HR measured at specific time intervals - immediately after the cool down period (HRR-0) and 3 minutes after the completion of the ETT (HRR-3).

Results

HRR-0 and HRR-3 increased over time, whereas VO_2max and MET_max did not show significant changes. There was a positive correlation between HRR at T0 and the exercise capacity at T0. HRR at T0 also showed a positive correlation with the exercise capacity at T1. There was no significant correlation between HRR measured at T0 and the change in the ratio of VO_2max and MET_max, as calculated by subtracting VO_2max and MET_max obtained at T0 from those obtained at T1, divided by VO_2max at T0 and multiplied by 100.

Conclusion

Post-exercise HRR measured at 3 weeks after the AMI onset can reflect the exercise capacity 3 months after the first ETT. However, it may be difficult to correlate post-exercise HRR at T0 with the degree of increase in cardiopulmonary exercise capacity in patients with AMI.

Effects of high-intensity interval versus continuous exercise training on post-exercise heart rate recovery in coronary heart-disease patients

BACKGROUND

Heart rate recovery (HRR) has been considered a prognostic and mortality indicator in both healthy and coronary patients. Physical exercise prescription has shown improvements in VO₂peak and HRR, but most of the studies have been carried out applying continuous training at a moderate intensity, being very limited the use of protocols of high intensity interval training in coronary patients. We aimed to compare the effects of a moderate continuous training (MCT) versus a high intensity interval training (HIIT) programme on VO₂peak and HRR.

METHODS

Seventy three coronary patients were assigned to either HIIT or MCT groups for 8weeks. Incremental exercise tests in a cycloergometer were performed to obtain VO₂peak data and heart rate was monitored during and after the exercise test to obtain heart rate recovery data.

RESULTS

Both exercise programmes significantly increase VO₂peak with a higher increase in the HIIT group (HIIT: 4.5±4.46ml/kg/min vs MCT: 2.46±3.57ml/kg/min; p=0.039). High intensity interval training resulted in a significantly increase in HRR at the first and second minute of the recovery phase (15,44±7,04 vs 21,22±6,62, p<0,0001 and 23,73±9,64 vs 31,52±8,02, p<0,0001, respectively).

CONCLUSIONS

The results of our research show that the application of HIIT to patients with chronic ischemic heart disease of low risk resulted in an improvement in VO₂peak, and also improvements in post-exercise heart-rate recovery, compared with continuous training.