Oxygen uptake on-kinetics during six-minute walk test predicts short-term outcomes after off-pump coronary artery bypass surgery

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Rocco, Isadora Salvador ; Viceconte, Marcela ; Pauletti, Hayanne Osiro ; Matos-Garcia, Bruna Caroline ; Marcondi, Natasha Oliveira ; Bublitz, Caroline ; Bolzan, Douglas William ; Moreira, Rita Simone Lopes ; Reis, Michel Silva ; Hossne, Nelson Americo, Jr. ; Gomes, Walter Jose ; Arena, Ross ; Guizilini, Solange

• Document type: Journal article
• Source: DISABILITY AND REHABILITATION; v. 41, n. 5, p. 7-pg., 2019-02-27.

Abstract

Purpose: We aimed to investigate the ability of oxygen uptake kinetics to predict short-term outcomes after off-pump coronary artery bypass grafting. Methods: Fifty-two patients aged 60.9 +/- 7.8 years waiting for off-pump coronary artery bypass surgery were evaluated. The 6-min walk test distance was performed pre-operatively, while simultaneously using a portable cardiopulmonary testing device. The transition of oxygen uptake kinetics from rest to exercise was recorded to calculate oxygen uptake kinetics fitting a monoexponential regression model. Oxygen uptake at steady state, constant time, and mean response time corrected by work rate were analysed. Short-term clinical outcomes were evaluated during the early post-operative of off-pump coronary artery bypass surgery. Results: Multivariate analysis showed body mass index, surgery time, and mean response time corrected by work rate as independent predictors for short-term outcomes. The optimal mean response time corrected by work rate cut-off to estimate short-term clinical outcomes was 1.51 x 10(-3) min(2)/ml. Patients with slower mean response time corrected by work rate demonstrated higher rates of hypertension, diabetes, EuroSCOREII, left ventricular dysfunction, and impaired 6-min walk test parameters. The per cent-predicted distance threshold of 66% in the pre-operative was associated with delayed oxygen uptake kinetics. Conclusions: Pre-operative oxygen uptake kinetics during 6-min walk test predicts short-term clinical outcomes after off-pump coronary artery bypass surgery. From a clinically applicable perspective, a threshold of 66% of pre-operative predicted 6-min walk test distance indicated slower kinetics, which leads to longer intensive care unit and post-surgery hospital length of stay. (AU)

• FAPESP's process: 12/50852-0 - Effects of an exercise protocol in hospital fase in pulmonary function, functionalcapacity, and peripheral muscle strength of patients with left ventricular dysfunction after coronary artery bypass graft
• Grantee: Solange Guizilini
• Support Opportunities: Regular Research Grants