Background Heart failure with preserved ejection fraction (HFpEF) is a prevalent syndrome, with exercise intolerance being one of its hallmarks, contributing to worse quality of life and mortality. High-intensity interval training is an emerging training option, but its efficacy in HFpEF patients is still unknown. Design Single-blinded randomized clinical trial. Methods Single-blinded randomized clinical trial with exercise training 3 days per week for 12 weeks. HFpEF patients were randomly assigned to high-intensity interval training or moderate continuous training. At baseline and after 12 week follow-up, patients underwent clinical assessment, echocardiography and cardiopulmonary exercise testing (CPET). Results Mean age was 60 ± 9 years and 63% were women. Both groups ( N = 19) showed improved peak oxygen consumption (VO2), but high-intensity interval training patients ( n = 10) had a significantly higher increase, of 22%, compared with 11% in the moderate continuous training ( n = 9) individuals (3.5 (3.1 to 4.0) vs. 1.9 (1.2 to 2.5) mL·kg−1·min−1, p < 0.001). Ventilatory efficiency and other CPET measures, as well as quality of life score, increased equally in the two groups. Left ventricular diastolic function also improved with training, reflected by a significant reduction in E/e′ ratio by echocardiography (−2.6 (−4.3 to −1.0) vs. −2.2 (−3.6 to −0.9) for high-intensity interval training and moderate continuous training, respectively; p < 0.01). There were no exercise-related adverse events. Conclusions This randomized clinical trial provided evidence that high-intensity interval training is a potential exercise modality for HFpEF patients, being more effective than moderate continuous training in improving peak VO2. However, the two strategies were equally effective in improving ventilatory efficiency and other CPET parameters, quality of life score and diastolic function after 3 months of training.

Purpose: Patients undergoing coronary artery bypass graft (CABG) surgery typically experience loss of cardiopulmonary capacity in the post-operative period. The purpose of this study was to evaluate the effects of different rehabilitation protocols used in inpatient cardiac rehabilitation on functional capacity and pulmonary function in patient status post-CABG surgery. Methods: This was a single-blind randomized controlled trial. The primary endpoint of functional capacity and secondary endpoints of lung capacity and respiratory muscle function were assessed in patients scheduled to undergo CABG. After surgery, 40 patients were randomly assigned across 1 of 4 inpatient cardiac rehabilitation groups: G1, inspiratory muscle training, active upper limb and lower limb exercise training, and early ambulation; G2, same protocol as G1 without inspiratory muscle training; G3, inspiratory muscle training alone; and G4, control. All groups received chest physical therapy and expiratory positive airway pressure. Patients were reassessed on post-operative day 6 and post-discharge day 30 (including cardiopulmonary exercise testing). Results: The 6-min walk distance on post-operative day 6 was significantly higher in groups that included exercise training (G1 and G2), remaining higher at 30 d post-discharge (P < .001 between groups). Peak oxygen uptake on day 30 was also higher in G1 and G2 (P = .005). All groups achieved similar recovery of lung function. Conclusion: Protocols G1 and G2, which included a systematic plan for early ambulation and upper and lower limb exercise, attenuated fitness losses while in the hospital and significantly enhanced recovery 1 mo after CABG.

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