Chronic heart failure–related myopathy and exercise training: a developing therapy for heart failure symptoms

Development of a complex exercise rehabilitation intervention for people with pulmonary hypertension: the supervised pulmonary hypertension exercise rehabilitation (SPHERe) trial

BACKGROUND

People with pulmonary hypertension (PH) are not routinely referred for exercise rehabilitation despite the potential for reducing breathlessness and improving quality of life. We describe the development of a supervised pulmonary hypertension exercise rehabilitation (SPHERe) programme for people with PH.

METHODS

Development was completed in three phases: (1) systematic review, (2) stakeholder engagement with consensus from patients and experts and (3) prepilot intervention acceptability testing. We completed systematic reviews to identify international cardiopulmonary rehabilitation guidance and trials of exercise-based interventions for people with PH. Evidence from systematic reviews and stakeholder consensus shaped the SPHERe intervention, including addition of individual behavioural support sessions to promote exercise adherence. The draft SPHERe intervention was ratified through discussions with multidisciplinary professionals and people living with PH. We acceptability tested the centre-based intervention with eight participants in a prepilot development phase which identified a number of condition-specific issues relating to safety and fear avoidance of activity. Comprehensive intervention practitioner training manuals were produced to ensure standardised delivery. Participant workbooks were developed and piloted. Trial recruitment began in January 2020 but was subsequently suspended in March 2020 further to COVID-19 pandemic 'lockdowns'. In response to the pandemic, we undertook further development work to redesign the intervention to be suitable for exclusively home-based online delivery. Recruitment to the revised protocol began in June 2021.

DISCUSSION

The final SPHERe intervention incorporated weekly home-based online group exercise and behavioural support 'coaching' sessions supervised by trained practitioners, with a personalised home exercise plan and the optional loan of a stationary exercise bike. The intervention was fully manualised with clear pathways for assessment and individualised exercise prescription. The clinical and cost-effectiveness of the SPHERe online rehabilitation intervention is currently being tested in a UK multicentre randomised controlled trial.

TRIAL REGISTRATION NUMBER

ISCRTN10608766.

Cardiac resynchronization therapy reduces metaboreflex contribution to the ventilatory response in heart failure population

Background. Metaboreflex overactivation has been proprosed to explain exaggerated hyperventilation in heart failure population. We investigated the metaboreflex activation after cardiac resynchronization therapy (CRT). Methods. 10 heart failure patients (mean left ventricular ejection fraction (LVEF) 27 ± 4%) schedulded for CRT implantation were prospectively studied. At baseline and after 6 month follow up two maximal cardiopulmonary exercise tests with and without regional circulatory occlusion (RCO) during recovery were performed. RCO was achieved by inflation of bilateral upper thigh tourniquets 30 mmHg above peak systolic blood pressure during 3 minutes after peak exercise. Metaboreflex contribution to the ventilatory response was assessed as the difference in ventilatory data at the third minute during recovery between the two tests (Δ). Results. Patients had enhanced VE/VCO(2) slope (40 ± 9) and an evident metaboreflex contribution to the high ventilatory response (ΔVE: 3 ± 4 L/min; P = 0.05, ΔRR: 4.5 ± 4/min; P = 0.003 and ΔVE/VCO(2): 5.5 ± 4; P = 0.007). 6 months after CRT implantation, NYHA class, LVEF, peak VO(2) and VE/VCO(2) were significantly improved (1.4 ± 0.5; P < 0.001, 42 ± 7%; P < 0.001, 16.5 ± 3 mL/kg/min; P = 0.003; 33 ± 10; P = 0.01). Metaboreflex contribution to VE, RR, and VE/VCO(2) was reduced compared with baseline (P = 0.08, P = 0.01 and P = 0.4 resp.). Conclusion. 6 months after CRT metaboreflex contribution to the ventilatory response is reduced.

[The ventilatory response in chronic heart failure population]

Symptom-limited exercise test with peak oxygen consumption measurement possesses a strong prognostic value in chronic heart failure. This parameter allowing notably the selection of patients for heart transplant. Nevertheless, sub maximal effort and beta blocker therapy tend to limit its prognostic value. The ventilatory response evaluated by the minute ventilation - carbon dioxide production (VE/VCO2) linear regression slope during effort is generally considered to be a significant predictor of mortality and hospitalizations in HF population. An enhanced ventilatory response is correlated with a poorer prognostic. In addition, this parameter is not influenced by the intensity of the effort neither by the betablocker therapy. But, physiological determinants are not clear yet. Aim of our study is to confirm the important place of the (VE/VCO2) slope in HF patient's evaluation.

Physical training in patients with chronic heart failure of ischemic origin: effect on exercise capacity and left ventricular remodeling

BACKGROUND

Physical training is a well-known complementary treatment for chronic heart failure (CHF); however, many aspects require further studies. One of them is the impact on remodeling of the left ventricle (LV). The purpose of this study was to evaluate the effect of 6 months of training on LV, exercise capacity and safety issues in patients with ischemic CHF.

METHODS

Fifty patients (mean age 60.1+/-9.2 years) with ischemic CHF, New York Heart Association (NYHA) classification class II and III and left ventricular ejection fraction (LVEF) <or=35% were randomized into groups: undergoing 6-month training (25 patients) and not trained (25 patients). In both groups at baseline and at 6 months a cardiopulmonary exercise test and magnetic resonance imaging (MRI) with evaluation of LV were performed. Training was limited by the achievement of 80% of the predicted heart rate at VO2peak achieved at the baseline cardiopulmonary exercise test.

RESULTS

All patients completed the 6-month observation. No serious adverse events were found in either group. Exercise capacity improved only in the trained group (VO2peak increased by 31%). At 6 months in the trained group there was a tendency towards an improvement in some LV parameters: ejection fraction, end-diastolic volume and wall motion score index (WMSI), whereas an opposite trend was seen in the controls (P<0.05, P<0.05 and P<0.01 for comparison of LVEFs, end-diastolic volumes and WMSIs, respectively).

CONCLUSIONS

Six-month training in ischemic CHF patients is a safe modality. Training improves exercise capacity. There was no negative impact on LV morphology, and a trend towards improvement of functional parameters on MRI may suggest an anti-remodeling effect of training in patients with ischemic CHF.