INCREASED MORTALITY IN ELDERLY INDIVIDUALS RECEIVING DIGOXIN THERAPY - RESULTS FROM THE BRONX LONGITUDINAL AGING STUDY

Background: Digoxin is a common medication used in older people. The e ffects of digoxin consumption on morbidity and mortality in an elderly community-dwelling population, free from terminal disease including a history of congestive heart failure, were assessed in a prospective 8 -year study. Methods: Participants came from the cohort of the Bronx L ongitudinal Aging Study (n=488, mean age 79 years at the time of entry into the study) who were being followed in a non-interventional study designed to assess risk factors for the development of cardiac, cereb rovascular and dementing illnesses. Participants were re-evaluated on an annual basis unless a morbid or mortal event occurred. The use of d igoxin was reported by 14% of the cohort. Rates of development of majo r morbid and mortal cardiovascular events were calculated for those re ceiving and not receiving digoxin. A univariate regression analysis wa s performed using a Cox proportional hazards model. A multivariate ana lysis was then carried out, which controlled for age, sex, average num ber of medications taken, diuretic consumption, average number of card iac rhythm disturbances, and average number of positive responses to c ardiac history questions. Results: The all-cause mortality was 10.2 pe r 100 person-years for participants receiving digoxin compared with 5. 2 per 100 person-years for participants not receiving the drug (P<0.00 1). The results for cardiovascular death were similar. There was no di fference in the rate of non-fatal cardiovascular events. The cumulativ e all-cause mortality was higher among those receiving digoxin through out the study. After adjusting for differences in the baseline charact eristics of the participants, the Cox proportional hazards regression analysis showed that digoxin use may be an independent predictor of mo rtality. Conclusion: in an ambulatory population of elderly participan ts, digoxin should be administered with caution and only when there ar e clear medical indications for treatment.