Permanent cardiac pacing after a cardiac operation: Predicting the use of permanent pacemakers

Background. The need for permanent cardiac pacing after cardiac operations is infrequent but associated with increased morbidity and resource utilizat ion. We identified patient risk factors for pacemaker insertion to enable d evelopment of a predictive model. Methods. Data were collected prospectively for 10,421 consecutive patients who had cardiac operations between January 1990 and December 1995. Two hund red fifty-five patients (2.4%) were identified as having received a permane nt pacemaker during the same hospitalization. Logistic regression analysis was performed to determine the independent, multivariate predictors of perm anent pacing. The predictive accuracy and precision of the logistic regress ion model was evaluated in the 1996 database of 2,236 consecutive patients by the calculation of Brier scores. Results. Light independent predictors of permanent pacemaker requirement we re identified. The factor-adjusted odds ratios (OR) with 95% confidence int erval (CI) associated with each predictor are as follows: (1) valve replace ment surgery (aortic: OR 5.8, CI 3.9-8.7; mitral: OR 4.9, CI 3.1-7.8; tricu spid: OR 8.0, CI 5.5-11.9; double: OR 8.9, CI 5.5-14.6; and triple: OR 7.5, CI 2.9-19.3); (2) repeat operation: OR 2.4, CI 1.8-3.3; (3) age 75 years o r older: OR 3.0, CI 2.0-4.4; (4) ablative arrhythmia operation: OR 4.2, CI 1.9-9.5; (5) mitral valve annular reconstruction: OR 2.4, CI 1.4-4.2; (6) u se of cold blood cardioplegia: OR 2.0, CI 1.2-3.6; (7) preoperative renal f ailure: OR 1.6, CI 1.0-2.6; and (8) active endocarditis: OR 1.7, CI 0.9-3.0 . A model for postoperative permanent pacemaker requirement using the eight predictors was formulated and tested (Brier score = 0.017 +/- 0.003; Z = 0 .18). Conclusions. The proposed predictive model correlated highly with actual pa cemaker use, which suggests that the requirement for pacing results from ei ther operative trauma or increased ischemic burden. Preoperative identifica tion of patients at increased risk of conduction disturbances may allow for earlier detection and improved treatment. Patients requiring postoperative pacing had increased morbidity and length of stay. (C) 1998 by The Society of Thoracic Surgeons.