A new algorithm for optimization of rate-adaptive pacing improves exercise tolerance in patients with HFpEF.

AIM: To develop an algorithm for optimization of rate-adaptive pacing settings in heart failure patients with preserved ejection fraction (HFpEF) and permanent cardiac pacing. METHODS: This is a prospective randomized controlled study. A total of 54 patients with HFpEF, permanent atrial fibrillation (AF), and VVIR pacing were randomized to an intervention group with optimization of rate-adaptation parameters by using cardiopulmonary exercise testing (CPET) and pacemaker stress echocardiography (PASE), and to a control group with conventional programming. CPET, 6-min walk test (6-mwt), echocardiography (echo), Duke Activity Status Index (DASI), and Minnesota questionnaire (MLHFQ) were performed at baseline and after 3 months. PASE was used to exclude exercise-induced ischemia and to determine safe upper sensor rate. Pacing parameters were corrected to achieve optimal heart rate increments of 3-6 bpm for 1 mL/min/kg of VO2 (oxygen uptake). RESULTS: After 3 months, the intervention group demonstrated significant improvement of VO2 peak by 1.64 ± 1.6 mL/min/kg, anaerobic threshold by 1.33 ± 1.3 mL/min/kg, exercise time by 170 ± 98 s, 6-mwt distance by 75 ± 63 m (P < .0001 for all), DASI by 5.23 points (P = .009), MLHFQ-score (reduction by 9 points, P < .0001), and echo parameters (decrease in LA volume from 108 (84; 132) to 95 (85; 130) mL, P = .026; E/e' from 11.7 ± 3.2 to 10.4 ± 2.9, P = .025; systolic pulmonary artery pressure (SPAP) from 44 ± 14 to 39 ± 12 mm Hg, P = .001) compared to the control group. CONCLUSION: An algorithm incorporating CPET and PASE for optimal programming of rate-adaptation parameters is a valuable tool to improve exercise capacity in HFpEF patients with permanent AF and VVIR pacing who remain exercise intolerant after conventional programming.

Interval training early after heart failure decompensation is safe and improves exercise tolerance and quality of life in selected patients.

Aims To evaluate safety and efficacy of moderate intensity interval exercise training early after heart failure decompensation on exercise tolerance and health-related quality of life (HRQoL). Methods and results This is a prospective randomized controlled study. We screened 234 consecutive patients admitted with decompensated heart failure; 46 patients (42 men/4 women; 61 ± 12 years of age) were randomized to a moderate intensity aerobic interval training ( n = 24) or to a control group ( n = 22). Patients underwent cardiopulmonary exercise testing, echocardiography and Minnesota Living with Heart Failure questionnaire (MLHFQ) at baseline, after three weeks and after three months. After three weeks, peak-VO2 increased by 17% in the training group ( p = 0.003) with further increase by 10% after three months ( p < 0.001) but did not change significantly in controls. MLHFQ score improved after three weeks, with better results in the training group (from 64.6 ± 15.6 to 30.8 ± 12.9, p < 0.001). After three months, MLHFQ further improved in the exercise training group, but not in controls. Left ventricular ejection fraction was not significantly different between the two groups at baseline and after three months. No serious adverse events related to exercise testing or training were observed. Conclusions Interval exercise training early after an episode of heart failure decompensation is safe and effective in improving exercise tolerance and health-related quality of life in selected patients after achievement of clinical stability. Positive effects remained sustained after three months. Further studies are needed to define role and indications for interval exercise training early after heart failure decompensation.