Impact of Age on Comorbidities and Outcomes in Heart Failure With Reduced Ejection Fraction.

OBJECTIVES:This study sought to determine whether age modifies the impact of key comorbidities on clinical outcomes for patients with heart failure with reduced ejection fraction (HFrEF). BACKGROUND:Comorbidities impact outcomes in HFrEF. However, the effect of age on the impact of comorbidities on prognosis is not clearly understood. METHODS:Cox proportional hazards models were used assessed interactions between age and comorbidities on the primary composite endpoint (all-cause mortality or hospitalization) and secondary endpoints in the HF-ACTION (Heart Failure: A Controlled Trial Investigating Outcomes of Exercise Training) multicenter trial of 2,331 patients with HFrEF. RESULTS:Age did not significantly modify the effect of any comorbidity on the primary endpoint. However, age significantly modified the effect of body mass index (BMI) on all-cause mortality (interaction p = 0.02). Among patients ≥70 years of age, there was a U-shaped relationship between BMI and 1-year mortality, where BMI of 20 kg/m2 corresponded to 17.6%; a BMI of 30 kg/m2 corresponded to 7.0%; and a BMI of 40 kg/m2 corresponded to 11%. For patients <60 years of age, mortality increased nonsignificantly from 3.2% to 3.7% with increasing BMI. Age also modified the effect of depressive symptoms on all-cause mortality (interaction p = 0.03). Among patients ≥70 years of age, a 1-year mortality rate significantly increased from 7.8% for a Beck Depression Inventory (BDI) score of 5% to 15.6% for BDI of 20. For patients <60 years of age, mortality was nonsignificantly related to BDI. Cumulative comorbidity scores were stronger predictors than age for mortality/hospitalization. CONCLUSIONS:In chronic HFrEF, age markedly altered the impact of BMI and depressive symptoms on all-cause mortality, with much higher risk in older patients, but was not as strong a predictor of mortality/hospitalizations as cumulative comorbidity score. (Heart Failure: A Controlled Trial Investigating Outcomes of Exercise Training [HF-ACTION]; NCT00047437).