A total of 4,534 men and women from the Worcester metropolitan area with independently confirmed decompensated HF requiring hospital admission comprised the study population. The mean age of our study sample was 76 years and the majority (56.9%) were women; among all patients studied, 1,153 (25.4%) experienced a first (incident) episode of HF.
Ejection fraction (EF) data were available in only 37% of hospitalized study patients. Compared to patients without EF data, those with available EF data were younger, had a lower body mass index (BMI), were less likely to have a medical history of coronary heart disease, chronic obstructive pulmonary disease (COPD), diabetes, cancer, renal disease, stroke and congestive heart failure (all p’s <0.05). Patients with EF data were more likely to report chest pain, edema, orthopnea and weight gain, were more likely to be treated with ACE inhibitors, ARBs, digoxin, β blockers, lipid lowering agents and nitrates, and were more likely to survive the index hospitalization (all p’s <.05). In a multivariable regression analysis, patients with EF assessments were younger and had a lower prevalence of several comorbidities, including coronary heart disease, COPD, diabetes or stroke (all p’s <0.05), compared to patients without EF measurements. Patients in the 1995 cohort were more likely to have EF data compared to patients in the 2000 cohort.
Baseline Characteristics According to Age
Older patients hospitalized with decompensated HF were more likely to be female, Caucasian and to have a lower BMI compared to patients who were less than 65 years (). Older patients had lower serum creatinine and higher blood urea nitrogen levels, higher systolic and lower diastolic blood pressure findings, a lower heart rate, and were less likely to smoke and to have preserved renal function, as represented by an estimated glomerular filtration fate (eGFR) ≥60. Compared to younger patients, older patients were more likely to have a medical history of coronary heart disease, stroke, cancer, and heart failure, and less likely to have a history of chronic obstructive pulmonary disease, diabetes, peripheral vascular disease, and renal disease. Older patients were also more likely to have had multiple comorbidities previously diagnosed than younger patients (). Older patients with decompensated HF were more likely to have a do not resuscitate order (DNR) in their clinical charts, have a shorter average hospital stay, and were more likely to die during the index hospitalization as compared to younger patients hospitalized with acute HF.
Characteristics of patients with acute heart failure according to age (Worcester Heart Failure Study)
Compared to patients <65 years, older patients were less likely to exhibit all signs and symptoms of acute HF with the exception of generalized weakness. Because symptoms may differ by level of EF, we examined association of age and acute symptomatology in patients with data on EF and according to preserved (EF≥50%) vs. impaired EF and found that age related differences in the reporting of chest pain, nausea, orthopnea, and weight gain were observed only in patients with impaired EF.
Treatment Practices According to Age
Older patients were less likely to have been prescribed the majority of effective cardiac therapies examined during hospitalization for decompensated HF including ACE inhibitors, β blockers, and ARBs (). Older patients were more likely than younger patients to have received diuretics during their index hospitalization. Older adults were also significantly less likely to have been recommended to adopt various non-pharmacologic interventions, such as low fat or low salt diets, fluid restriction, and cardiac rehabilitation by their physicians as compared to younger patients.
Treatment practices in patients with acute heart failure according to age (Worcester Heart Failure Study)
Because treatment practices evolved considerably over the period under study, we examined age differences in treatment practices separately by study year and found that disease modifying medications were prescribed significantly more often in 2000 compared to 1995, particularly in patients <65 years and in those 75–84 years old (p=<.01).
Factors associated with pharmacologic interventions according to age
In a series of regression analyses, we examined the association between age and the failure to receive symptom modifying medications (diuretics and digoxin) and disease modifying medications (ACE inhibitors, ARBs and β blockers) while controlling for a variety of demographic and clinical factors that may affect the prescribing of these medications (). The crude odds of receiving symptom modifying medications was significantly higher in older, compared to younger, patients. While older patients were still more likely than younger patients to receive symptom modifying medications, the association between age and receipt of symptom modifying medications was somewhat attenuated, however, in multivariable adjusted models. In contrast, older patients were significantly less likely than younger patients to receive disease modifying medications in both crude and multivariable adjusted models. When regression analyses were stratified by study year (1995 and 2000) findings did not vary significantly.
When we carried out a series of regression analyses among patients in whom EF data were available (n=1,509), the failure to receive symptom modifying medications according to patient’s age was similar to those found in the total study sample. The crude and multivariable adjusted odds of receiving symptom modifying medications was higher in older, as compared to younger, participants, although the adjusted odds ratios were not statistically significant, possibly due to the smaller sample size (adjusted ORs compared to those <65 years: OR 65–74 years = 0.91, 95% CI = 0.19, 4.21; OR 75–84 years = 0.29, 95% CI = 0.05, 1.45; OR ≥85 years = 0.54 95% CI = 0.09, 3.27). In contrast to findings in the total sample, receipt of disease modifying medications did not vary according to age in patients with EF data (adjusted ORs of failure to receive disease modifying medications compared to those <65 years: OR 65–74 years = 0.76, 95% CI = 0.52, 1.10; OR 75–84 years = 1.11, 95% CI = 0.78, 1.57; OR ≥85 years = 0.92 95% CI = 0.61, 1.38).
Age-specific differences in hospital and long-term mortality
We examined the association between age and in-hospital death adjusting for several demographic, medical history and clinical characteristics as well as time period of hospitalization (). In-hospital death rates increased markedly with advancing age from 3% in patients <65 years to 8.2% in those ≥75 years. In multivariable adjusted analyses, the odds of dying during hospitalization remained considerably higher in older, compared to younger, patients. When we restricted this analysis to patients with EF data, results were similar with the odds of dying during hospitalization significantly higher in older, as compared to younger, patients (adjusted ORs compared to those <65 years: OR 65–74 years = 1.58, 95% CI = 0.55, 4.56; OR 75–84 years = 3.03, 95% CI = 1.13, 8.11; OR ≥85 years = 3.36 95% CI = 1.15, 9.88).
In a similar manner, we examined the relation between age and the risk of dying at 30-days post hospital admission, and 1-year after hospital discharge, adjusting for several demographic, medical history, and clinical characteristics (). Thirty-day crude mortality rates increased with age from 5.5% in patients <65 years to 17.6% in patients ≥85 years. In the multivariable adjusted analyses, the odds of dying during the first 30-days after hospital admission increased with advancing age. Results were similar when the analysis was restricted to patients with available EF data (adjusted ORs compared to those <65 years: OR 65–74 years = 1.45, 95% CI = 0.68, 3.10; OR 75–84 years = 2.68, 95% CI = 1.33, 5.42; OR ≥85 years = 3.58 95% CI = 1.68, 7.00).
Because DNR orders may impact that association between age and mortality, we also stratified this analysis according to the presence of DNR orders during hospitalization and found that the odds of 30-day mortality increased with advancing age in those without a DNR (OR 65–74 years = 1.79; 95% CI = 0.96, 3.34; OR ≥85 years = 2.46; 95% CI = 1.27, 4.77) but were nonsignificantly associated with age among those with a DNR order present in their hospital charts (OR 65–74 years = 1.50; 95% CI = 0.78, 2.87; OR ≥85 years = 0.86; 95% CI = 0.46, 1.61).
One-year crude death rates increased with advancing age from 26.9% in patients <65 years to 47.7% in patients ≥85 years (). In the multivariable adjusted models, the odds of dying during the first year after hospital discharge increased with advancing age. The results were similar when we carried out this analysis only in patients with EF data available (adjusted ORs compared to those <65 years: OR 65–74 years = 1.08, 95% CI = 0.69, 1.69; OR 75–84 years = 1.83, 95% CI = 1.21, 2.79; OR ≥85 years = 2.84 95% CI = 1.78, 4.54). Similar results were also obtained with regards to the association between advancing age and the risk of dying during the first year after hospital discharge, as were observed with regards to the 30 day death rates after hospital admission, when we carried out separate multivariable adjusted analyses in those who did or did not have a DNR order during their index hospitalization for HF.
Advanced patient age was also negatively associated with more extended long-term survival. The five year post hospital discharge survival rates were approximately 50% in patients <55 years, 35% in those 55–65 years, 27% in those 65–74 years, 21% in those 75–84 years, and 12% in patients ≥85 years (). A proportional hazards regression analysis was carried out to control for previously described potentially confounding prognostic factors in examining the association of age with long-term survival. Consistent with our univariate findings, post-discharge mortality was directly related to advancing age (adjusted OR compared to patients <65 years: 65–74 years = 1.48, 95% CI 1.32, 1.65; 75–84 years = 1.84, 95% CI 1.67, 2.04; ≥85 years = 2.23, 95% CI 2.00, 2.49).
Long-term Survival According to Age (Worcester Heart Failure Study)
Among patients with EF data, we stratified the proportional hazards regression analysis according to EF findings [preserved left ventricular function (EF≥50%; n=652) compared with impaired ventricular function (EF<50%; n=857)] and controlled for the same potentially confounding factors described above. In both groups, post-discharge mortality was directly associated with advancing age (adjusted ORs compared to those <65 years: preserved function: OR 65–74 years = 1.23, 95% CI = 0.87, 1.74; OR 75–84 years = 1.75, 95% CI = 1.26, 2.43; OR ≥85 years = 2.75, 95% CI = 1.92, 3.94; impaired function: OR 65–74 years = 1.37, 95% CI = 1.06, 1.77; OR 75–84 years = 1.74, 95% CI = 1.37, 2.23; OR ≥85 years = 2.34, 95% CI = 1.74, 3.14).