Chronic Heart Failure in Ambulatory Outpatients and the Impact of Multiple Co-Morbidities on Survival

Abstract:

Heart failure (HF) is associated with premature mortality. 18,307 HF patients were referred to 26 specialized outpatient HF clinics between 1999-2010 and included HF with reduced and preserved cardiac function. During 12 years of follow-up, we determined the impact of different co-morbidities, identified at first data entry, on all cause death. 69% of these HF patients were male, mean age 64.8(14.3) yrs, HF duration was 2.6(4.5) yrs, median number of relevant co-morbidities per patient was 4, and the mean follow-up was 5 years. The total number of individual co-morbidities were 35 and included 17 CV, 12 non-CV, and 6 interventions. Stepwise Cox proportional hazards regression was calculated to describe the impact of co-morbidities on survival. The data are described as a point estimate (95% confidence interval) [p value: 0.001, <0.01, *<0.05] in a multivariate analysis: Stent 0.78 (0.68, 0.9)[ ]; Arthritis 0.82 (0.74, 0.91)[ ]; Dyslipidemia 0.85 (0.78, 0.92)[ ]; Systemic Hypertension 0.87 (0.8, 0.94)[ ]; Diabetes Type II 1.12 (1.01, 1.23)[ ]; Atrial Fibrillation 1.13 (1.04, 1.23)[ ]; Valve Disease 1.14 (1.04, 1.26)[ ]; Bradyarrhythmia 1.22 (1.03, 1.45)[*]; Pulmonary Hypertension 1.24 (1.09, 1.42)[ ]; Cancer 1.28 (1.14, 1.44)[ ]; Smoking Current 1.28 (1.11, 1.47)[ ]; Diabetes Type I 1.39 (1.05, 1.84)[ ]; PVD 1.39 (1.24, 1.55)[ ]; Diabetes Type II - Insulin 1.45 (1.28, 1.64)[ ]; Renal dysfunction1.67 (1.52, 1.82)[ ]; Liver Disease 1.69 (1.29, 2.21)[ ]. To analyze the impact of cumulative co-morbidities adjusted for age, < 3 co-morbidities was chosen as the reference (hazard ration [HR]=1.0). Unadjusted and adjusted HR (95% CI) are presented. For 3-5 co-morbidities the HR's are 1.19 (1.08-1.31) and 1.07 (0.97-1.17); 6-10 co-morbidities 1.80 (1.64-1.97) and 1.45 (1.32-1.59); >10 co-morbidities 2.56 (2.17-3.03) and 2.03 (1.71-2.40). The log-rank test for the groupings of these co-morbidities was significant at p<0.001. In this large prospective cohort, increasing co-morbidities were associated with worse survival in these ambulatory heart failure outpatients. Type I diabetes, peripheral vascular disease, diabetes requiring insulin, renal dysfunction, and liver disease were the five highest risk co-morbidities.