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 ((Formula presented.)), carbon dioxide output ((Formula presented.)), respiratory gas exchange ratio, expiratory volume ((Formula presented.)), ventilatory equivalents for O 2 ((Formula presented.)) and CO 2 ((Formula presented.)), respiratory rate (RR), tidal volume (V t), heart rate (HR), oxygen pulse ((Formula presented.) /HR), blood lactate, Borg ratings of perceived exertion (RPE) and exercise-onset (Formula presented.) 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 (Formula presented.) and (Formula presented.) were significantly elevated, (Formula presented.) and (Formula presented.) /HR were significantly lowered, and exercise-onset (Formula presented.) kinetics were significantly slower in AS patients vs. healthy controls (P < 0.05). Although the AVA was restored by mini-AVR in AS patients, (Formula presented.) and (Formula presented.) further worsened significantly within 5 days after surgery, accompanied by elevations in Borg RPE, (Formula presented.) and RR, and lowered V t. At 21 days after mini-AVR, exercise-onset (Formula presented.) 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.