ORLANDO – Three simple, routinely collected measurements together provide a lot of insight into the risk faced by community-dwelling patients hospitalized for acute decompensated heart failure, according to data collected from 3,628 patients at one U.S. center.
The three measures are blood urea nitrogen (BUN), systolic blood pressure, and serum creatinine. Using dichotomous cutoffs first calculated a decade ago, these three parameters distinguish up to an eightfold range of postdischarge mortality during the 30 or 90 days following an index hospitalization, and up to a fourfold range of risk for rehospitalization for heart failure during the ensuing 30 or 90 days, Dr. Sithu Win said at the American Heart Association scientific sessions.
Dr. Sithu Win
Applying this three-measure assessment to patients hospitalized with acute decompensated heart failure “may guide care-transition planning and promote efficient allocation of limited resources,” said Dr. Win, a cardiologist at the Mayo Clinic in Rochester, Minn. The next step is to try to figure out the best way to use this risk prognostication in routine practice, he added.
Researchers published the original analysis that identified BUN, systolic BP, and serum creatinine as key prognostic measures in 2005 using data taken from more than 65,000 U.S. heart failure patients enrolled in ADHERE (Acute Decompensated Heart Failure National Registry) (JAMA. 2005 Feb 2;293[5]:572-80). Using a classification and regression tree analysis, the 2005 study verified dichotomous cutoffs for these three parameters that identified patients at highest risk for in-hospital mortality.
The 2005 study prioritized the application of these cutoffs to define in-hospital mortality risk: first BUN, then the systolic BP criterion, and lastly the serum creatinine criterion. This resulted in five risk levels: Highest-risk patients had a BUN of at least 43 mg/dL, a systolic BP of less than 115 mm Hg, and a serum creatinine of at least 2.75 mg/dL. Lowest-risk patients had a BUN of less than 43 mg/dL and a systolic BP of more than 115 mm Hg. (In lower-risk patients, serum-creatinine level dropped out as a risk determinant.) The analysis also created three categories of patients with intermediate risk based on various combinations of the three measures.
The new study run by Dr. Win and his associates evaluated how this risk-assessment tool developed to predict in-hospital mortality performed for predicting event rates among community-based heart failure patients who had a total of 5,918 hospitalizations for acute decompensated heart failure at the Mayo Clinic during 2000-2013. They averaged 78 years old, half were women, and 48% had heart failure with preserved ejection fraction.
The risk-level distribution of the 3,628 Mayo patients closely matched the pattern seen in the original ADHERE registry: 63% were low risk, 17% were at intermediate level 3 (the lowest risk level in the intermediate range), 13% were at intermediate level 2, 5% at intermediate level 1, and 2% were categorized as high risk.
For 30-day mortality post hospitalization, patients at the highest risk level had a mortality rate eightfold higher than did the lowest-risk patients, those rated intermediate level 1 had a fivefold higher mortality rate, intermediate level 2 patients had a threefold higher rate, and those at intermediate 3 had a 50% higher rate, Dr. Win reported. During the 90 days after discharge, mortality rates relative to the lowest risk level ranged from a sixfold higher rate among the highest-risk patients to a 50% higher rate among patients with an intermediate 3 designation.
Analysis of rehospitalizations for heart failure showed that, by 30 days after hospitalization, the readmission rate ran threefold higher in the highest-risk patients, compared with those at the lowest risk and fourfold higher among those at intermediate risk level 1. Heart failure readmissions by 90 days following the index hospitalization ran threefold higher for both the highest-risk patients as well as those at intermediate level 1, compared with the patients at lowest risk.
The new analyses also showed that roughly similar risk patterns occurred regardless of whether patients had heart failure with reduced or preserved ejection fraction during their index hospitalization, although the relatively increased rate of 30-day mortality with a worse risk profile was most dramatic among patients with reduced ejection fraction. Age, sex, and comorbidity severity did not have a marked effect on the relationships between event rates and risk levels, Dr. Win said.
Dr. Win had no disclosures.
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