Relation between mode of pacing and long-term survival in the very elderly

OBJECTIVES This study analyzes the relationship between pacing mode and lon g-term survival in a large group of very elderly patients (greater than or equal to 80 years old). BACKGROUND The relationship between pacing mode and long-term survival is n ot clear. Because the number of very elderly who are candidates for pacing is increasing, issues related to pacemaker (PM) use in the elderly have imp ortant clinical and economic implications. METHODS We retrospectively reviewed 432 patients (mean age, 84.5 +/- 3.9 ye ars) who received their initial PM (ventricular in 310 and dual chamber in 122) between 1980 and 1992. Follow-up was complete (3.5 +/- 2.6 years). Obs erved survival was estimated by the Kaplan-Meier method. Age- and gender-ma tched cohorts from the Minnesota population were used for expected survival . Log-rank test and Cox regression hazard model were used for univariate an d multivariate analyses. RESULTS Patients with ventricular PMs appeared to have poor overall surviva l compared with those with dual-chamber PMs. Observed survival after PM imp lantation in high grade atrioventricular block (AVB) patients was significa ntly worse than expected survival of the age- and gender-matched population (p < 0.0001), whereas observed survival of patients with sinus node dysfun ction was not significantly different from expected survival of the matched population (p = 0.413). By univariate analysis, ventricular pacing in pati ents with AVE appeared to be associated with poor survival compared with du al-chamber pacing (hazard ratio [HR] 2.08; 95% cofidence interval [CI] 1.33 to 3.33). After multivariate analysis, this difference was no longer signi ficant (HR 1.41; 95% CI 0.88 to 2.27). Independent predictors of all-cause mortality were number of comorbid illnesses, New York Heart Association fun ctional class, left ventricular depression and older age at implant. Pacing mode was not an independent predictor of overall survival. Older age at im plantation, diabetes mellitus, dementia, history of paroxysmal atrial fibri llation and earlier year of implantation were independent predictors of ven tricular pacemaker selection. CONCLUSIONS After PM implantation, long-term survival among very elderly pa tients was not affected by pacing mode after correction of baseline differe nces. Selection bias was present in pacing mode in the very elderly, with v entricular pacing selected for sicker and older patients, perhaps partly ex plaining the apparent "beneficial impact on survival" observed with dual-ch amber pacing. (C) 1999 by the American College of Cardiology.