A hospital perspective on the cost-effectiveness of β-blockade for prophylaxis of atrial fibrillation after cardiothoracic surgery

Background: Prophylactic beta-blockade is the recommended strategy for suppressing atrial fibrillation after cardiothoracic surgery (CTS). However, P-blockade's impact on the hospital length of stay (LOS) and other economic end points has not been adequately assessed. Objective: The present evaluation sought to determine whether beta-blocker use after CTS is a cost-effective strategy for the prevention of postoperative atrial fibrillation (POAF). Methods: This was a piggyback cost-effectiveness analysis of a prospective cohort evaluation comprising 1660 patients undergoing CTS at an urban academic hospital from October 1999 to October 2003. Patients receiving beta-blocker prophylaxis were matched 1:1 with control patients not receiving prophylaxis based on age > 70 years, valvular surgery, history of atrial fibrillation, male sex, and use of preoperative digoxin or beta-blockers. The incidence of POAF, total hospital costs, and LOS were compared in each group. Nonparametric bootstrapping analysis was performed to examine the study results as part of a quadrant analysis and to calculate CIs for the incremental cost-effectiveness ratio. LOS and total costs were also compared in patients with and without POAF, regardless of beta-blockcr use. Results: Use of prophylactic beta-blockade was associated with a 17.3% reduction in the incidence of POAF (P = 0.02) and a 2.2-day reduction in LOS (P = 0.001) compared with nonuse. It also was associated with a 25.7% reduction in total hospital costs compared with nonuse (mean [SD], $30,978 [$33,108] vs $41,700 [$67,369], respectively; P < 0.001), possibly due to a 27.6% reduction in room and board costs ($11,144 [$15,398] vs $14,920 [$22,132]; P < 0.001). In the bootstrapping analysis, 99.0% of the time prophylactic beta-blockade fell into quadrant IV, which indicated superior effectiveness and lower total costs. Regardless of beta-blocker use, patients who developed POAF had a significantly longer LOS compared with those who did not develop POAF (14.7 [19.1] days vs 10.1 [11.1] days, respectively; P < 0.001) and higher total costs ($47,240 [$85,941] vs $32,516 [$34,644]; P < 0.001). Conclusions: At the institution studied, beta-blocker prophylaxis against POAF after CTS was associated with significantly reduced total costs compared with nonuse of beta-blocker prophylaxis. Patients who developed POAF had significantly increased LOS and total costs compared with those who did not develop POAF. An adequately powered prospective, randomized, placebo-controlled trial is necessary to confirm the results of this evaluation.