Six-Minute Walk Test Predicts Postoperative Delirium After Transcatheter Aortic Valve Replacement

Abstract

Objective: This study investigated the incidence and risk factors of postoperative delirium (POD) after transcatheter aortic valve replacement (TAVR) and to evaluate the association between preoperative conditions, particularly frailty, and POD.

Design: Observational, case-control study.

Setting: Single-center university hospital.

Participants: The study comprised 124 patients who underwent TAVR and were divided into the following two groups: group D (patients diagnosed with POD) and group C (patients without POD).

Interventions: None.

Measurements and main results: Twenty-seven patients (21.7%) developed POD (95% confidence interval 14.9%-30.1%). POD was defined as a diagnosis of delirium using the Confusion Assessment Method for Intensive Care Unit scale during the patients' intensive care unit stay. Preoperative and postoperative data of patient characteristics were obtained from their medical records. A multivariate logistic regression analysis was performed using variables associated with POD incidence. Frailty scores were significantly higher in group D than in group C. The distance covered in the six-minute walk test (6MD) was significantly shorter in group D than in group C. The risk of developing POD was significantly higher in patients with a 6MD shorter than 220 m. Multivariate logistic regression analysis showed that a shorter 6MD was an independent risk factor for POD (odds ratio 5.66; p = 0.004).

Conclusion: In the present study, POD was seen in 21.7% of the patients who underwent TAVR. A 6MD shorter than 220 m was an independent preoperative risk factor for POD. For patients at high risk of POD, more careful management in the perioperative period may reduce POD.

Keywords: Clinical Frailty Scale; postoperative delirium; six-minute walk test; transcatheter aortic valve replacement.