Muscle wasting after coronary artery bypass graft surgery : impact on post-operative clinical status and effect of exercise-based rehabilitation

Background: Coronary artery bypass graft (CABG) surgery is known to induce significant muscle wasting. It remains to be investigated whether muscle wasting after CABG surgery relates to a worse clinical status at entry of rehabilitation and exercise-based rehabilitation remediates such muscle wasting. Design: Prospective observational study. Methods: In 21 males, changes in lean tissue mass (LTM) after CABG surgery were assessed and during a 12-week endurance exercise-based rehabilitation intervention. Changes in blood parameters and cardiopulmonary exercise capacity were assessed, and relations with changes in LTM were analysed. Results: LTM decreased by −1.9 ± 2.5 kg (p r = 0.58–0.61, p p  Conclusion: In males, CABG-induced LTM reduction was associated with a worse aerobic exercise tolerance at entry of rehabilitation, but this LTM reduction was fully remediated by endurance exercise-based rehabilitation.</p

The effect of minimally invasive surgical aortic valve replacement on postoperative pulmonary and skeletal muscle function

NEW FINDINGS: What is the central question of this study? How does surgical aortic valve replacement affect cardiopulmonary and muscle function during exercise? What is the main finding and its importance? Early after the surgical replacement of the aortic valve a significant decline in pulmonary function was observed, which was followed by a decline in skeletal muscle function in the subsequent weeks of recovery. These date reiterate, despite restoration of aortic valve function, the need for a tailored rehabilitation programme for the respiratory and peripheral muscular system. ABSTRACT: Suboptimal post-operative improvements in functional capacity are often observed after minimally invasive aortic valve replacement (mini-AVR). It remains to be studied how AVR affects the cardiopulmonary and skeletal muscle function during exercise to explain these clinical observations and to provide a basis for improved/tailored post-operative rehabilitation. Twenty-two patients with severe aortic stenosis (AS) (aortic valve area (AVA) <1.0 cm²) were pre-operatively compared to 22 healthy controls during submaximal constant-workload endurance-type exercise for oxygen uptake ( V ̇ O 2 ), carbon dioxide output ( V ̇ C O 2 ), respiratory gas exchange ratio, expiratory volume ( V ̇ E ), ventilatory equivalents for O2 ( V ̇ E / V ̇ O 2 ) and CO2 ( V ̇ E / V ̇ C O 2 ), respiratory rate (RR), tidal volume (Vt ), heart rate (HR), oxygen pulse ( V ̇ O 2 /HR), blood lactate, Borg ratings of perceived exertion (RPE) and exercise-onset V ̇ O 2 kinetics. These exercise tests were repeated at 5 and 21 days after AVR surgery (n = 14), along with echocardiographic examinations. Respiratory exchange ratio and ventilatory equivalents ( V ̇ E / V ̇ O 2 and V ̇ E / V ̇ C O 2 ) were significantly elevated, V ̇ O 2 and V ̇ O 2 /HR were significantly lowered, and exercise-onset V ̇ O 2 kinetics were significantly slower in AS patients vs. healthy controls (P < 0.05). Although the AVA was restored by mini-AVR in AS patients, V ̇ E / V ̇ O 2 and V ̇ E / V ̇ C O 2 further worsened significantly within 5 days after surgery, accompanied by elevations in Borg RPE, V ̇ E and RR, and lowered Vt . At 21 days after mini-AVR, exercise-onset V ̇ O 2 kinetics further slowed significantly (P < 0.05). A decline in pulmonary function was observed early after mini-AVR surgery, which was followed by a decline in skeletal muscle function in the subsequent weeks of recovery. Therefore, a tailored rehabilitation programme should include training modalities for the respiratory and peripheral muscular system.status: publishe

The effect of minimally invasive surgical aortic valve replacement on postoperative pulmonary and skeletal muscle function

Suboptimal post-operative improvements in functional capacity are often observed after minimally invasive aortic valve replacement (mini-AVR). It remains to be studied how AVR affects the cardiopulmonary and skeletal muscle function during exercise to explain these clinical observations and to provide a basis for improved/tailored post-operative rehabilitation. Twentytwo patients with severe aortic stenosis (AS) (aortic valve area (AVA) <1.0 cm2) were preoperatively compared to 22 healthy controls during submaximal constant-workload endurancetype exercise for oxygen uptake (V̇ O2 ), carbon dioxide output (V̇ CO2 ), respiratory gas exchange ratio, expiratory volume (V̇ E), ventilatory equivalents for O2 (V̇ E/V̇ O2 ) and CO2 (V̇ E/V̇ CO2 ), respiratory rate (RR), tidal volume (Vt), heart rate (HR), oxygen pulse (V̇ O2 /HR), blood lactate, Borg ratings of perceived exertion (RPE) and exercise-onset V̇ O2 kinetics. These exercise tests were repeated at 5 and 21 days after AVR surgery (n = 14), along with echocardiographic examinations. Respiratory exchange ratio and ventilatory equivalents (V̇ E/V̇ O2 and V̇ E/V̇ CO2 ) were significantly elevated, V̇ O2 and V̇ O2 /HR were significantly lowered, and exercise-onset V̇ O2 kinetics were significantly slower in AS patients vs. healthy controls (P < 0.05). Although the AVA was restored by mini-AVR in AS patients, V̇ E/V̇ O2 and V̇E/V̇ CO2 further worsened significantly within 5 days after surgery, accompanied by elevations in Borg RPE, V̇ E and RR, and lowered Vt. At 21 days after mini-AVR, exercise-onset V̇ O2 kinetics further slowed significantly (P < 0.05). A decline in pulmonary function was observed early after mini-AVR surgery, which was followed by a decline in skeletal muscle function in the subsequent weeks of recovery. Therefore, a tailored rehabilitation programme should include training modalities for the respiratory and peripheral muscular system