Compromised Cardiopulmonary Exercise Capacity in Patients Early After Endoscopic Atraumatic Coronary Artery Bypass Graft: Implications for Rehabilitation

Abstract

Objective: The purpose of this work was to test the hypothesis that cardiopulmonary exercise tolerance is better preserved early after endoscopic atraumatic coronary artery bypass graft (endo-ACAB) surgery versus coronary artery bypass graft (CABG) surgery. Design: Twenty endo-ACAB surgery patients, 20 CABG surgery patients, and 15 healthy subjects executed a maximal cardiopulmonary exercise test, with assessment and comparison of cycling power output, O2 uptake, CO2 output, respiratory gas exchange ratio, end-tidal O2 and CO2 pressures, equivalents for O2 uptake and CO2 output, heart rate, O2 pulse, expiratory volume, tidal volume, respiratory rate, at peak exercise and ventilatory threshold. In patients, forced expiratory volume and forced vital capacity were measured. Results: Oxygen uptake, CO2 output, expiratory and tidal volume, equivalents for O2 uptake and CO2 output, end-tidal O2 and CO2 pressures at peak exercise (matched peak respiratory gas exchange ratio between patient groups), and ventilatory threshold were significantly worse in patients versus healthy controls (PG 0.05; observed power, 90.80). All these parameters, and lung function, were, however, comparable between CABG and endo-ACAB surgery patients (P 9 0.10). Conclusions: Exercise tolerance and ventilatory function during exercise seems, in contrast to expectation, equally compromised early after endo-ACAB surgery as opposed to after CABG surgery. These data may signify the need for exercise-based rehabilitation intervention early after endo-ACAB surgery.