Effect of intraoperative dexmedetomidine on long-term survival in older patients after major noncardiac surgery: 3-year follow-up of a randomized trial

Abstract

Study objectiveTo assess the impact of intraoperative dexmedetomidine on long-term outcomes of older patients following major noncardiac surgery mainly for cancer. DesignA long-term follow-up of patients enrolled in a randomized trial. SettingThe initial trial was performed in a tertiary care hospital in Beijing, China. ParticipantsPatients aged 60 years or older who were scheduled for major noncardiac surgery. InterventionParticipants were randomized to receive either dexmedetomidine (a loading dose of 0.6 μg/kg over 10 min, followed by a continuous infusion of 0.5 μg/kg/h until 1 h before end of surgery) or placebo during anesthesia. MeasurementsThe primary endpoint was overall survival. Secondary endpoints included recurrence-free survival and event-free survival. Cox proportional hazard models were used to adjust for predefined confounding factors. Propensity score matching was employed for sensitive analysis. ResultsAmong 620 patients who were randomized in the initial trial, 619 were included in the long-term analysis (mean age 69 years, 40% female, 77% oncological surgery). The median follow-up duration was 42 months (interquartile range 41 to 45). Overall survival did not differ between the two groups: there were 49/309 (15.9%) deaths with dexmedetomidine versus 63/310 (20.3%) with placebo (adjusted hazard ratio [HR] 0.78, 95% CI 0.53–1.13, P = 0.187). Recurrence-free survival was improved with dexmedetomidine (68/309 [22.0%] events with dexmedetomidine versus 98/310 [31.6%] with placebo; adjusted HR 0.67, 95% CI 0.49–0.92, P = 0.012). Event-free survival was also improved with dexmedetomidine (120/309 [38.8%] events with dexmedetomidine versus 145/310 [46.8%] with placebo; adjusted HR 0.78, 95% CI 0.61–1.00, P = 0.047). Results were similar after propensity-score matching and in the subgroup of cancer patients. ConclusionsIn older patients having major noncardiac surgery mainly for cancer, intraoperative dexmedetomidine did not improve overall survival but was associated with improved recurrence-free and event-free survivals.