Beta-blockers can help older patients with heart failure live longer lives, but only if their condition is caused by a poorly-functioning left ventricle, according to a study in the Jan. 13 issue of the Journal of the American College of Cardiology. The researchers believe their findings could lead to clarification of guidelines on beta-blocker drug use among older patients.
Physicians divide patients into two groups, those who have left ventricle systolic dysfunction (LVSD), and those who have preserved systolic function, commonly known as a ‘stiff heart.’ Approximately 75 percent of patients with heart failure are over age 65 and about half of them fall into the stiff heart category.
“We don't really understand the underlying pathophysiology of heart failure among patients in that latter group,” said the study’s lead author Adrian Hernandez, MD, a cardiologist at Duke University Medical Center in Durham, N.C. “We do know, however, that patients with ‘stiff hearts’ tend to be older women who generally have just as poor outcomes as others with compromised ventricular function.”
Current guidelines call for beta-blocker use in patients with weakened left ventricles, but they are silent on the use of the drugs among patients with normal left ventricles.
Professional guidelines are based upon findings from large, clinical trials. But such studies tend to include disproportionate numbers of younger, healthier patients, quite unlike those most commonly encountered in hospital or community practice settings, “so it is not entirely clear that the findings would be the same,” according to Hernandez.
The investigators examined hospital records of 7,154 patients with heart failure in the OPTIMIZE-HF registry. The median age for the patients in the current study 78 (compared to a median age of 65 among heart failure patients enrolled in clinical trials) and a significant number of the study patients had multiple health problems. All were all eligible to undergo beta-blocker therapy.
The researchers divided the patients into two groups, those who had LVSD, and those who had preserved ventricular function and then merged the clinical records with Medicare data so they could track the patients as long as possible.
"We found that there were significantly higher death and re-hospitalization rates after one year among our study population when compared with those found among younger, healthier, study populations,” Hernandez said.
The investigators discovered that upon discharge from the hospital, 60 percent of the patients with weakened ventricles were prescribed beta-blockers, compared with 39 percent of the patients with stiff hearts.
After adjusting for variables that could account for some of the differences between the two groups, the researchers found that those with weakened ventricles who took beta-blockers experienced a 23 percent lower risk of death and an 11 percent lower rate of re-hospitalization, compared with those were not prescribed the drugs.
Among patients with preserved systolic function, beta-blockers appeared to have no significant impact on lowering the risk of death or re-hospitalization.
Hernandez said that the study is valuable because it offers new information about beta-blocker use among elderly, sicker patients with heart failure—the kind of patients physicians are likely to see in their community settings, and specifically for those with preserved systolic function.
GlaxoSmithKline funded the study.