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.

This is the peer reviewed version of the following article: Boujemaa, H, Yilmaz, A, Robic, B, et al. The effect of minimally invasive surgical aortic valve replacement on postoperative pulmonary and skeletal muscle function. Experimental Physiology. 2019; 104: 855– 865. https://doi.org/10.1113/EP087407 , which has been published in final form at https://doi.org/10.1113/EP087407 . This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.