Adverse Drug Events and Associated Factors in Heart Failure Therapy Among the Very Elderly

INTRODUCTION: Heart failure (HF) is common in older adults and standard therapy involves the use of multiple medications. We assessed the nature, frequency, and factors associated with adverse drug events (ADEs) associated with standard HF therapy among older adults greater than 75 years of age. The efficacy and predictors of ADEs were assessed in this patient population, as well. METHODS: Systematic review using standardized databases including MEDLINE, Ageline, and CINAHL from January 1st 1988 to January 1st, 2010 and references from published literature. Randomized trials and studies with observational, cohort, and cross-sectional design were included. Two investigators independently selected the studies and extracted the data (kappa = 0.86). RESULTS: Twenty-five studies were identified. ADEs were reported in 13/23 (57%) studies. Syncope, bradycardia, and hypotension as a result of beta blockers occurred in greater frequency compared to younger populations. Spironolactone therapy resulted in increased rates of hyperkalemia, acute renal failure, and medication discontinuation. Factors associated with ADEs included advanced age, poor left ventricular function, and increasing New York Heart Association Class. Efficacy of beta blockers and ACE inhibitors appears to extend to the elderly population, but the magnitude of effect size is unclear. Very few studies reported associations between ADE and patients’ comorbidities (4/13 studies, 31%) or functional status (3/13 studies, 23%). CONCLUSION: ADEs in CHF therapy among the very elderly occurred at a greater frequency, but were generally poorly characterized in the literature despite a relatively common occurrence. Further studies are warranted.