These "precipitating factors" identify patients at higher and lower risk of in-hospital and postdischarge adverse outcomes.

Increased attention to these factors, many of which are avoidable, is important in optimizing the management of heart failure, the authors conclude.

The study, known as Organized Program to Initiate Lifesaving Treatment in Hospitalized Patients With Heart Failure (OPTIMIZE-HF), is published in the April 28, 2008, issue of the Archives of Internal Medicine.

The authors, led by Dr Gregg Fonarow (University of California, Los Angeles), note that a number of factors have been identified that may acutely exacerbate heart failure and contribute to the patient's hospitalization.

These include arrhythmias, myocardial ischemia, respiratory infection, uncontrolled hypertension, and nonadherence to medications and diet.

But few studies have examined the frequency with which these factors are present among patients hospitalized for heart failure or whether there is an association between such factors and subsequent clinical outcomes.

They thus analyzed data on this from OPTIMIZE-HF, a registry and performance-improvement program for patients hospitalized for HF.

They report that from 2003 to 2004, 259 US hospitals in OPTIMIZE-HF submitted data on 48 612 patients (mean age 73.1 years, mean ejection fraction 39.0%), with a prespecified subgroup of at least 10% providing 60- to 90-day follow-up data. Identifiable factors contributing to heart-failure hospitalization were identified at admission.

Results showed that of the 48 612 patients, 29 814 (61.3%) had one or more precipitating factors identified, with pneumonia/respiratory process, ischemia, arrhythmia, and uncontrolled hypertension being most frequent.

Pneumonia, ischemia, and worsening renal function were independently associated with higher in-hospital mortality, and ischemia and worsening renal function were associated with a higher risk of follow-up mortality.

In contrast, uncontrolled hypertension was associated with lower in-hospital mortality and lower postdischarge death/rehospitalization.

Explaining this, Fonarow et al note that these patients can usually be readily stabilized in the hospital with blood-pressure control within a relatively short length of stay and lower risk of adverse near-term outcomes.

Similarly, helping patients to follow a correct diet and resuming correct medication is easier to manage than some other precipitating factors, which would also explain the lower mortality associated with these factors.

Fonarow et al point out that understanding whether and to what extent precipitants of heart-failure hospitalization influence length of stay, mortality, and rehospitalization risk is important because this knowledge may help guide clinicians in designing more effective management strategies for patients.

They note that national heart-failure guidelines recommend that patients hospitalized for heart failure undergo evaluation for precipitating factors and suggest that proper detection and treatment of precipitating factors is an important part of the management of acute decompensated heart failure, but that these recommendations were level of evidence C, expert opinion only.

These OPTIMIZE-HF data lend further support to these recommendations and provide data demonstrating that certain precipitating factors are associated with clinical outcomes independent of other established prognostic factors.

Patients identified as being at higher risk of adverse outcomes may benefit from closer monitoring during hospitalization and more frequent follow-up after discharge," they add.

They also suggest that several of these precipitating factors, such as nonadherence to diet and medications, may be reduced by improving patient education, and others could be reduced by improving disease-management strategies.

"Because pneumonia/respiratory process was the most common precipitating factor and was associated with worse outcomes, every effort should be made to prevent pneumonia in patients with heart failure, including rigorous influenza and pneumococcal vaccination.

Risk of ischemia and ACS may be reduced with antiplatelet agents, statin therapy, and, possibly, revascularization in eligible patients.

Disease-management programs and treatment plans for patients with heart failure should include appropriate strategies for these concomitant conditions, and exacerbation of these conditions should be avoided to the extent possible," they write.

"In future studies we plan to target how specific interventions based on these precipitating factors, such as flu vaccinations, may help this high-risk heart-failure population," Fonarow added

1. Fonarow GC, Abraham WT, Albert NM, et al. Factors identified as precipitating hospital admissions for heart failure and clinical outcomes. Findings from OPTIMIZE-HF. Arch Intern Med 2008; 168:847-854.