Impact of maximum phonation time on postoperative dysphagia and prognosis after cardiac surgery

Objective: The incidence of postoperative complications, including dysphagia, increases as the population undergoing cardiovascular surgery ages. This study aimed to explore the potential of maximum phonation time (MPT) as a simple tool for predicting postextubation dysphagia (PED) and major adverse cardiac and cerebrovascular events (MACCEs). Methods: This retrospective study included 442 patients who underwent elective cardiac surgery at a university hospital. MPT was measured before surgery, and patients were stratified into 2 groups based on normal and abnormal MPTs. Postoperative complications, including PED and MACCEs, were also investigated. Swallowing status was assessed using the Food Intake Level Scale. Results: MPT predicted PED with prevalence of 11.0% and 18.0% in the normal and abnormal MPT groups, respectively (P = .01). During the follow-up period, MACCEs developed in 17.0% of patients. Frailty, European System for Cardiac Operative Risk Evaluation II score, PED, and MPT were markedly associated with MACCEs (adjusted hazard ratios: 2.25, 1.08, 1.96, and 0.96, respectively). Mediation analysis revealed that MPT positively influenced PED and MACCEs, whereas PED positively influenced MACCEs. The trend in restricted cubic spline analysis indicated that the hazard ratio for MACCEs increased sharply when MPT was <10 seconds. Conclusions: These findings underscore the potential of MPT as a valuable tool in the preoperative assessment and management of patients undergoing cardiac surgery. By incorporating MPT into routine preoperative evaluations, clinicians can identify patients at a higher risk of PED and MACCEs, allowing for targeted interventions and closer postoperative monitoring. This may improve patient outcomes and reduce the health care costs associated with these complications.