Risks of In-Hospital Worsening Heart Failure

The results of a recent study found that in-hospital worsening heart failure was common and associated with higher rates of mortality, all-cause readmission, and Medicare payments [J Am Heart Assoc. 2014;3:e001088. DOI:10.1161/JAHA.114.001088].

Adam D. DeVore, MD, Duke Clinical Research Institute, and colleagues conducted a retrospective, observational study of 63,727 patients using data from ADHERE [Acute Decompensated Heart Failure National Registry], a large,
multicenter registry of patients who were hospitalized with acute heart failure.

“We know from clinical experience and clinical trials that a subset of patients [who] are hospitalized with heart failure will, despite receiving appropriate and aggressive medical treatment, go on to have persistent or worsening signs or symptoms of heart failure, requiring an escalation of care,” said Dr. DeVore in an interview with First Report Managed Care. “We labeled this common scenario as in-hospital worsening heart failure. Our hope is that by studying this group of patients and tailoring treatment strategies for them that we may be able to improve patient outcomes.”

The researchers collected data on demographics, comorbidities, medications, hospital course, laboratory test results, procedures, and discharge disposition. Standard analytic files for fee-for-service Medicare beneficiaries were obtained from the Centers for Medicare & Medicaid Services. Registry hospitalizations that occurred between January 2001 and December 2004 were then linked to Medicare inpatient claims.

Patients were categorized into 3 groups according to their experience during the index hospitalization: (1) patients with a complicated hospital presentation; (2) in-hospital worsening heart failure; or (3) an uncomplicated hospital course.

Outcomes of interest included:
• Mortality, readmission, and postdischarge Medicare payments

• Specifically, adjusted and unadjusted associations between each study group and all-cause mortality
• All-cause readmission
• Heart failure readmission
• Days alive and out of the hospital
• Post-discharge Medicare payments at both 30 days and 1 year

The researchers also analyzed hospital length of stay, in-hospital mortality, and Medicare payments to the hospital for the index hospitalization for each group.

The researchers found 7032 patients (11%) developed in-hospital worsening heart failure, 15,361 (24.1%) had a complicated hospital presentation, and 41,334 (64.9%) had an uncomplicated hospital course. Patients with worsening heart failure were more likely to be male and younger in age. Certain comorbidities were also more common in patients with worsening heart failure, including anemia, chronic kidney disease, diabetes, and peripheral vascular disease. They were also more likely to have a history of reduced left ventricular ejection fraction and a heart failure hospitalization in the prior 6 months.

Results showed patients with worsening heart failure had the poorest outcomes at 30 days and 1 year (Table). Mean hospital length of stay was also the longest for patients with worsening heart failure at 10 days compared with 4.8 days for patients with an uncomplicated hospital course and 6.3 days for patients with a complicated presentation. Median Medicare payment after discharge (in 2010 US dollars) for patients with worsening heart failure was $1045 at 30 days and $19,642 at 1 year compared with $544 at 30 days and $17,379 at 1 year for patients with a complicated presentation and $375 at 30 days and $13,199 at 1 year for patients with an uncomplicated hospital course.

The adjusted hazard ratio (HR) for mortality at 30 days was highest for patients with worsening heart failure compared with patients who had an uncomplicated course (HR, 2.56; 99% confidence interval [CI], 2.34-2.8) and at 1 year (HR, 1.66; 99% CI, 1.58-1.74). HRs for all-cause readmission were 1.24 at 30 days (99% CI, 1.14-1.35) and 1.11 at 1 year (99% CI, 1.05-1.16) for patients with worsening heart failure compared with those who had an uncomplicated course. Patients with worsening heart failure also showed a higher adjusted cost ratio with regard to post-discharge Medicare payments at 30 days (HR, 1.35; 99% CI, 1.24-1.46) and at 1 year (HR, 1.13; 99% CI, 1.08-1.18).

The researchers acknowledged study limitations, including that the study population was limited to patients in the ADHERE registry so the results may not be generalizable to other patient populations. Additionally, the researchers were able to adjust for only those variables that were collected in ADHERE.

In conclusion, Dr. DeVore added, “Our study was the first to examine the prevalence and outcomes of patients with in-hospital worsening heart failure in a real-world setting. We are currently in the process of trying to examine this in more detail to understand the timing of in-hospital worsening heart failure during a hospital course and to see if it can be predicted at the time of hospital admission. In the future, we hope to develop treatment strategies to prevent in-hospital worsening heart failure.”—Mary Mihalovic