Multimorbidity, polypharmacy, and mortality in older patients with pacemakers.

Background: The prevalence of multimorbidity and polypharmacy and its association with all-cause mortality in older patients with pacemakers are largely unknown. We aimed to clarify the prevalence of multimorbidity and polypharmacy, and its association with all-cause mortality in patients ≥75 years of age with pacemakers.

Methods: We retrospectively investigated 256 patients aged ≥75 years (mean age 84.0 ± 5.3 years; 45.7% male) with newly implanted pacemakers. The study endpoint was all-cause mortality ("with events"). Multimorbidity was defined as a Charlson Comorbidity Index ≥3. Polypharmacy was defined as the use of ≥5 medications.

Results: During the follow-up period (median, 3.1 years), 60 all-cause deaths were reported. The Charlson Comorbidity Index (2.9 ± 1.9 vs. 1.7 ± 1.7, < .001) and prevalence of multimorbidity (56.7% vs. 26.0%, < .001) were significantly higher in deceased patients than in survivors. The number of drugs (6.9 ± 3.0 vs. 5.9 ± 3.3, = .03) and the prevalence of polypharmacy (78.3% vs. 63.8%, = .04) were significantly higher in patients with events than in those without events. The event-free survival rate was significantly higher among patients without multimorbidity than in those with multimorbidity (log-rank, < .001), and was also significantly higher among patients without polypharmacy than in those with polypharmacy (log-rank, < .001). Multimorbidity (hazard ratio [HR]: 3.21; 95% confidence interval [CI]: 1.85-5.58; < .001) and polypharmacy (HR: 1.97; 95% CI: 1.03-3.77; = .04) were independent predictors of all-cause mortality.

Conclusions: Multimorbidity and its associated polypharmacy, which are common in the older population, are prevalent in patients with pacemakers and are independent predictors of poor prognosis.