Peak O2 -pulse predicts exercise training-induced changes in peak V̇O2 in heart failure with preserved ejection fraction

Comparison of exercise training modalities and change in peak oxygen consumption in heart failure with preserved ejection fraction: a secondary analysis of the OptimEx-Clin trial

AIMS

Exercise training (ET) is an effective therapy in heart failure with preserved ejection fraction (HFpEF), but the influence of different ET characteristics is unclear. We aimed to evaluate the associations between ET frequency, duration, intensity [% heart rate reserve (%HRR)] and estimated energy expenditure (EEE) with the change in peak oxygen consumption (V̇O2) over 3 months of moderate continuous training (MCT, 5×/week) or high-intensity interval training (HIIT, 3×/week) in HFpEF.

METHODS AND RESULTS

ET duration and heart rate (HR) were recorded with a smartphone application. EEE was calculated using the HR data during ET and the individual HR-V̇O2 relationships during cardiopulmonary exercise testing. Differences between groups and associations between ET characteristics and peak V̇O2 change were assessed with linear regression analyses. Peak V̇O2 improved by 9.2 ± 13.2% after MCT and 8.7 ± 15.9% after HIIT (P = 0.67). The average EEE of 1 HIIT session was equivalent to ∼1.42 MCT sessions and when adjusted for EEE, the mean difference between MCT and HIIT was -0.1% (P = 0.98). For both MCT and HIIT, peak V̇O2 change was positively associated with ET frequency (MCT: R2 = 0.103; HIIT: R2 = 0.149) and duration/week (MCT: R2 = 0.120; HIIT: R2 = 0.125; all P < 0.05). Average %HRR was negatively associated with peak V̇O2 change in MCT (R2 = 0.101; P = 0.034), whereas no significant association was found in HIIT (P = 0.234). Multiple regression analyses explained ∼1/3 of the variance in peak V̇O2 change.

CONCLUSION

In HFpEF, isocaloric HIIT and MCT seem to be equally effective over 3 months. Within each mode, increasing ET frequency or duration/week may be more effective to improve peak V̇O2 than increasing ET intensity.

Novel techniques for quantifying oxygen pulse curve characteristics during cardiopulmonary exercise testing in tetralogy of fallot

Background

Cardiopulmonary exercise testing (CPET) is used in evaluation of repaired tetralogy of Fallot (rTOF), particularly for pulmonary valve replacement need. Oxygen pulse (O2P) is the CPET surrogate for stroke volume and peripheral oxygen extraction.

Objectives

This study assessed O2P curve properties against non-invasive cardiac output monitoring (NICOM) and clinical testing.

Methods

This cross-sectional study included 44 rTOF patients and 10 controls. Three new evaluations for O2P curve analysis during CPET were developed. Best fit early and late regression slopes of the O2P curve were used to calculate: 1) the early to late ratio, or "O2 pulse response ratio" (O2PRR); 2) the portion of exercise until slope inflection, or "flattening fraction" (FF); 3) the area under the O2P response curve, or "O2P curve area".

Results

rTOF patients (median age 35.2 (27.6-39.4); 61% female) had a lower VO2 max (23.4 vs 45.6 ml/kg/min; p < 0.001) and O2P max (11.5 vs 19.1 ml/beat; p < 0.001) compared to controls. Those with a FF occurring <50% through exercise had a lower peak cardiac index and stroke volume, but not VO2 max, compared to those >50%. FF and O2P curve area significantly correlated with peak cardiac index, stroke volume, left and right ventricular ejection fraction, and right ventricular systolic pressure.

Conclusion

CPET remains an integral part in the evaluation of rTOF. We introduce three non-invasive methods to assess exercise hemodynamics using the O2P curve data. These evaluations demonstrated significant correlations with stroke volume, cardiac output, and right ventricular pressure.

Exercise Intolerance Is Associated with Cardiovascular Dysfunction in Long COVID-19 Syndrome

Background/Objectives: Cardiorespiratory complications are commonly reported among patients with long COVID-19 syndrome. However, their effects on exercise capacity remain inconclusive. We investigated the impact of long COVID-19 on exercise tolerance combining cardiopulmonary exercise testing (CPET) with resting echocardiographic data. Methods: Forty-two patients (55 ± 13 years), 149 ± 92 days post-hospital discharge, and ten healthy age-matched participants underwent resting echocardiography and an incremental CPET to the limit of tolerance. Left ventricular global longitudinal strain (LV-GLS) and the left ventricular ejection fraction (LVEF) were calculated to assess left ventricular systolic function. The E/e' ratio was estimated as a surrogate of left ventricular end-diastolic filling pressures. Tricuspid annular systolic velocity (SRV) was used to assess right ventricular systolic performance. Through tricuspid regurgitation velocity and inferior vena cava diameter, end-respiratory variations in systolic pulmonary artery pressure (PASP) were estimated. Peak work rate (WRpeak) and peak oxygen uptake (VO2peak) were measured via a ramp incremental symptom-limited CPET. Results: Compared to healthy participants, patients had a significantly (p < 0.05) lower LVEF (59 ± 4% versus 49 ± 5%) and greater left ventricular end-diastolic diameter (48 ± 2 versus 54 ± 5 cm). In patients, there was a significant association of E/e' with WRpeak (r = -0.325) and VO2peak (r = -0.341). SRV was significantly associated with WRpeak (r = 0.432) and VO2peak (r = 0.556). LV-GLS and PASP were significantly correlated with VO2peak (r = -0.358 and r = -0.345, respectively). Conclusions: In patients with long COVID-19 syndrome, exercise intolerance is associated with left ventricular diastolic performance, left ventricular end-diastolic pressure, PASP and SRV. These findings highlight the interrelationship of exercise intolerance with left and right ventricular performance in long COVID-19 syndrome.

Exercise as Medicine: Evaluation and Prescription for Adults with Congenital Heart Disease

PURPOSE OF REVIEW

Understanding exercise physiology as it relates to adult congenital heart disease (ACHD) can be complex. Here we review fundamental physiologic principles and provide a framework for application to the unique ACHD patient population.

RECENT FINDINGS

ACHD exercise participation has changed dramatically in the last 50 years. A modern approach focuses on exercise principles and individual anatomic and physiologic considerations. With an evolving better understanding of ACHD exercise physiology, we can strategize plans for patients to participate in dynamic and static exercises. Newly developed technologies including wearable devices provide additive information for ACHD providers for further assessment and monitoring. Preparation and assessment for ACHD patients prior to exercise require a thoughtful, personalized approach. Exercise prescriptions can be formulated to adequately meet the needs of our patients.

A year in heart failure: updates of clinical and preclinical findings

We witnessed major advances in the management of heart failure (HF) in 2022. Results of recent clinical and preclinical investigations aid preventive strategies, diagnostic efforts, and therapeutic interventions, and collectively, they hold promises for a more effective HF care for the near future. Accordingly, currently available information extends the 2021 European Society of Cardiology guidelines and provides a solid background for the introduction of improved clinical approaches in the number of HF-related cases. Elaboration on the relationships between epidemiological data and risk factors lead to better understanding of the pathophysiology of HF with reduced ejection fraction and HF with preserved ejection fraction. The clinical consequences of valvular dysfunctions are increasingly interpreted not only in their haemodynamic consequences but also in association with their pathogenetic factors and modern corrective treatment possibilities. The influence of coronavirus disease 2019 pandemic on the clinical care of HF appeared to be less intense in 2022 than before; hence, this period allowed to refine coronavirus disease 2019 management options for HF patients. Moreover, cardio-oncology emerges as a new subdiscipline providing significant improvements in clinical outcomes for oncology patients. Furthermore, the introduction of state-of-the-art molecular biologic methods, multi-omic approaches forecast improved phenotyping and precision medicine for HF. All above aspects are addressed in this article that highlights a selection of papers published in ESC Heart Failure in 2022.