Survival after heart failure

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Cardiology Review® Online, August 2007, Volume 24, Issue 8

We conducted a multi-hospital population-based study of 2445 residents of a large New England metropolitan area hospitalized with acute heart failure and found that the long-term prognosis for these patients remains poor. More than one third of patients died in the first year after hospital discharge,and nearly 4 of 5 patients died over the 5-year follow-up period. Several demographic and clinical factors were associated with an adverse prognosis. It is important to know the factors that negatively affect long-term survival after hospital discharge for decompensated heart failure so that treatment can be directed toward specific high-risk groups.

Heart failure is a major health problem in the United States, and its incidence has increased steadily in recent years.1,2 Although much progress has been made in the treatment of patients with heart failure, some studies indicate that long-term survival remains poor.3-5 In the Worcester Heart Failure Study, we evaluated the long-term prognosis of patients hospitalized with decompensated heart failure.6,7

Patients and methods

In 2000, trained nurse and physician reviewers examined the medical records of patients who were discharged from 11 Worcester, Massachusetts, hospitals with a possible diagnosis of heart failure.6,7 We excluded patients who died during hospitalization for acute heart failure (approximately 5% of the study sample).

Data regarding the patients' laboratory test results and demographic, clinical, history, and treatment characteristics were extracted from the medical records.6,7 Subsequent hospital medical records and death certificates were examined through the end of 2005 to obtain data about patients' long-term survival after discharge from all greater Worcester hospitals.

Results

The study sample included 2445 patients discharged from the 11 central Massachusetts hospitals after an episode of decompensated heart failure. About 75% of the study population had been previously diagnosed with heart failure, 43% of the subjects were men, and the mean age of the study sample was 76 years. All-cause death rates were 37% at 1 year after hospital discharge, 53% at 2 years, and 79% at 5 years after hospital discharge. These rates were slightly lower in patients with an incident episode of acute heart failure.

As shown in Table 1, subjects who died after discharge were older and were more likely to be white, to have lower levels of hemoglobin and blood pressure, and to have a body mass index below 25 kg/m2 at the time they entered the hospital, compared with survivors. They were also more likely to have higher levels of blood urea nitrogen and serum creatinine and to have been previously diagnosed with heart failure, stroke, renal disease, peripheral vascular disease, chronic lung disease, coronary heart disease, and anemia. They were less likely to have been treated with each of the cardiac medications evaluated in the study, except for digoxin, and were more likely to have presented to greater Worcester hospitals with edema and generalized weakness. They were less likely to have presented with orthopnea, nausea/vomiting, and chest pain. When analyses were limited to those who died or survived the first, high-risk year after hospitalization, similar factors were associated with an adverse long-term survival.

As shown in Table 2, white race, older age, having higher serum levels of blood urea nitrogen, having a lower blood pressure, having a body mass index below 25 kg/m2, having a higher heart rate, having edema, and having a history of heart failure, peripheral vascular disease, chronic lung disease, or stroke were shown on multivariate-adjusted regressional analysis to be associated with an increased risk of dying over the follow-up period. Patients with an initial episode of decompensated heart failure or those who had an episode during the first year after hospital discharge also had an increased risk of dying.

Discussion

Our results indicate that among the greater Worcester residents included in our study, patients who survived hospitalization for decompensated heart failure had a poor long-term prognosis. Only a few studies have assessed long-term survival in a community-based setting.5,8-10 One study showed unchanged incidence rates for new-onset heart failure during the period 1979-1984 to 1996-2000.9 The 5-year survival rates, however, were associated with significantly improved heart failure over that period. Another study, which included more than 1000 Framingham, Massachusetts, residents with new-onset heart failure, showed improvements in survival among men and women over a period of approximately 5 decades.11 A Scottish study showed improving trends in 3-year survival rates after new-onset heart failure over a study period of 8 years.12

The long-term prognosis for patients with heart failure may be improving, as shown by these and other studies. These improvements are probably the result of following published guidelines for the treatment of heart failure, expansion and effectiveness of outpatient clinics to treat ambulatory patients with heart failure, advances in medical treatment, and increased use of effective treatment regimens for hospital survivors of heart failure.13 Our data suggest, however, that heart failure in an elderly population is still a significant condition associated with a poor prognosis for the majority of hospitalized patients and needs to be more aggressively monitored and managed. Older patients, patients with lower body weight and blood pressure, increased heart rate and increased levels of blood urea nitrogen, patients with a prior history of selected comorbidities, and patients with certain presenting symptoms were at increased risk for an adverse outcome.

Investigators in a Scottish study of more than 31,000 patients who presented to the hospital with myocardial infarction, the 4 most common types of cancers, or a first admission for heart failure suggested that heart failure was more "malignant" than cancer.14 The results of our study indicate that this, in fact, may be the case. Although much progress in the treatment of patients with acute and chronic forms of heart failure has been made, it is important to know the factors that negatively affect long-term survival so that treatment can be directed toward specific high-risk groups. The effect of comorbid conditions on long-term prognosis must also be taken into account when making decisions about the use of more aggressive treatments, such as coronary revascularization procedures and automatic implantable defibrillators.

Findings from the Rochester Epidemiology Project indicated that among Olmsted County, Minnesota, residents with heart failure, the use of angiotensin-converting enzyme (ACE) inhibitors has increased substantially over time, whereas the use of beta blockers increased from 10% in 1979-1984 to 31% in 1996-2000.9 These data show that there is a trend toward observance of current guidelines regarding the use of effective cardiac treatments in patients with heart failure.1,14 The results of our study suggest that because postdischarge survivors were more likely to be prescribed beta blockers and ACE inhibitors than were decedents, these medications may help to improve the long-term prognosis of patients with heart failure.

Conclusions

Data regarding the long-term prognosis of patients hospitalized for decompensated heart failure are limited. Our community-wide study evaluating long-term survival in these patients showed that the prognosis is poor. We identified several demographic and clinical factors associated with a poor long-term prognosis, some of which can be effectively managed. These results emphasize the need to improve the treatment of patients with heart failure and to develop long-term approaches to improve survival.