Friday, January 2, 2009

Evidence-based, non-evidence-based β-blockers have similar effect on HF survival
By Maggie De Pano, DCRI Communications

Duke researchers found that the comparative effectiveness of evidence-based β-beta blockers (EBBBs) and non-evidence-based β-beta blockers (non-EBBBs) on the one-year survival of heart failure patients is similar. However, patients receiving EBBBs are more likely to be rehospitalized for heart failure.

The study was published December 2008 in the Archives of Internal Medicine.

Non-EBBBs such as atenolol are generally well tolerated and previous randomized trials have shown that they can improve the survival of patients who have had heart attacks. However, they have not been directly tested in patients with heart failure. EBBBs such as carvedilol, on the other hand, have a proven effect on survival, but they lack a definitive adverse side effect profile.

Physicians who are prescribing non-EBBBs to patients with high blood pressure or ischemic heart disease often face the choice of whether to switch to an EBBB when these patients develop heart failure. The authors acknowledged this clinical dilemma and wrote that studying observational data on heart failure patients who, for various reasons, have continued to use non-EBBBs may provide useful information on the clinical outcomes associated with the use of these drugs.

In their study, the authors analyzed the data of 11,959 North Carolina residents who were 65 years or older, eligible for Medicare and Medicaid with pharmacy benefits, and had had at least one hospitalization for heart failure during the period 2001 through 2004. The participants fell into one of three treatment groups: 7,034 had no β-blockers prescriptions filled in the first 30 days after being discharged from the hospital where they were initially diagnosed with heart failure; 2,757 had EBBB prescriptions filled; and 2,168 had non-EBBB prescriptions filled.

The authors found that patients who were not receiving β-blockers had a one-year death rate of 28.3 percent, patients receiving a non-EBBB 22.8 percent, and patients receiving an EBBB 24.2 percent. This means that either kind of β-blocker is associated with a substantial survival benefit, but the difference between those benefits is not statistically significant.

Meanwhile, the average number of times that patients on EBBBs had to be rehospitalized for heart failure and the cumulative length of days that they stayed in the hospital are higher compared with the other two treatment groups. In contrast, patients using non-EBBBs had shorter hospitals stays and demonstrated a trend toward fewer rehospitalizations overall.

Duke researchers who participated in the study include Judith M. Kramer, MD, MS; Lesley H. Curtis, PhD; Adrian Hernandez, MD; and Kevin J. Anstrom, PhD.

Read the full study here.