Preoperative cardiopulmonary exercise testing for risk assessment before elective coronary artery bypass grafting surgery

Abstract

Objective: To evaluate the feasibility and results of performing cardiopulmonary exercise test (CPET) in coronary artery disease (CAD) patients before elective coronary artery bypass grafting surgery (CABG). CPET has been increasingly employed in the evaluation of preoperative risk before noncardiac surgeries, but is still underutilized before cardiac surgery and may be useful, as clinical risk scores for preoperative assessment before cardiac surgeries have several limitations. Methods: Patients with CAD underwent CPET within 1 week before CABG. Oxygen consumption, oxygen pulse, oxygen consumption at the anaerobic threshold, minute ventilation/carbon dioxide relationship slope (VE/VCO2 slope), oxygen uptake efficiency slope (OUES) and heart rate recovery (HRR) were analyzed. The occurrence of complications during the test was recorded. Results: Twenty-eight patients (75% men), aged 61 (8) years, underwent preoperative CPET. There were no complications during CPET, even though 71.4% were interrupted by signs or symptoms of ischemia, and only 57% of the patients reached the anaerobic threshold.  Conclusions: Preoperative CPET before elective CABG was feasible and safe. However, a large proportion of patients did not achieve the anaerobic threshold. Therefore, VE/VCO2 slope, OUES and HRR may be the most useful CPET variables in the preoperative period. Key words: coronary artery disease, coronary artery bypass grafting, cardiopulmonary exercise test, preoperative assessment