Study examines comparative effectiveness of rhythm control vs. rate control drug treatment

An observational study that examined the comparative effectiveness of rhythm control vs. rate control drug treatment on mortality in patients with atrial fibrillation (a rapid, irregular heart beat) suggests there was little difference in mortality within four years of treatment, but rhythm control may be associated with more effective long-term outcomes, according to a report published Online First by Archives of Internal Medicine.

AF affects approximately 2.3 million Americans and 250,000 Canadians, and the condition has a complex therapy that may involve rate control agents, antiarrhythmic drugs, anticoagulant drugs and/or ablative techniques (use of a to eliminate the anatomic source of the ), according to study background.

"Controversy continues concerning the choice of rhythm control vs. rate control for atrial fibrillation (AF). A recent clinical trial showed no difference in five-year mortality between the two treatments. We aimed to determine whether the two strategies have similar effectiveness when applied to a general population of patients with AF with longer follow-up," the authors write as background.

Raluca Ionescu-Ittu, Ph.D., of the Harvard School of Public Health, Boston, and colleagues used population-based databases from Quebec, Canada, from 1999 to 2007 to select patients 66 years or older hospitalized with AF who did not have AF-related drug prescriptions in the year before they were hospitalized but received one within seven days of discharge.

"We found that with increasing follow-up time the mortality among the patients who newly initiated rhythm control therapy gradually decreased relative to those who initiated rate control drugs, reaching 23 percent reduction after eight years of follow-up," the authors comment.

The researchers note that recent clinical trials comparing the two treatments "concluded that there are no differences in mortality between the two treatment strategies."

"For the first four years after treatment initiation, our results in a population-based sample are similar to the results from the recent . In addition, we found a tendency toward a long-term protective effect for rhythm control drugs. The long-term benefits of rhythm control drugs in AF found in this study need to be assessed in future studies," the researchers conclude.

In an editorial, Thomas A. Dewland, M.D., and Gregory M. Marcus, M.D., M.A.S., of the University of California, San Francisco, write: "How do we best interpret this unexpected result given contrary evidence from prior randomized trials?"

"Although the findings of Ionescu-Ittu et al are provocative, they are insufficient to recommend a universal rhythm control strategy for all patients with AF. Randomization is a powerful tool that unfortunately cannot be reliably reproduced with statistical modeling," the authors conclude.

More information: Arch Intern Med. Published online June 4, 2012. doi:10.1001/archinternmed.2012.2266
Arch Intern Med. Published online June 4, 2012. doi:10.1001/archinternmed.2012.2332

Related Stories

The Medical Minute: Atrial Fibrillation -- What is It?

Oct 06, 2011

Atrial fibrillation (AF) is the most common heart rhythm disturbance in the United States and affects 2 to 4 million Americans. It is usually a disease of aging, however it can affect people of all ages -- 1 percent of people ...

The big risk factor for stroke that you may not know you have

Sep 15, 2011

A cardiac condition called atrial fibrillation, the most common cardiac arrhythmia, can increase your risk of stroke by 500 percent. That's why Anne B. Curtis, MD, Charles and Mary Bauer Professor and Chair of the University ...

Recommended for you

ASHG: MI without substantial CAD is minimally heritable

10 hours ago

(HealthDay)—The presence of myocardial infarction (MI) without substantial coronary artery disease (CAD) is not familial, according to a study presented at the annual meeting of the American Society of ...

New treatment for inherited cholesterol

15 hours ago

At the London Olympics in 2012, South African swimmer Cameron van den Burgh dedicated his world record-breaking win in the 100m breast stroke to one of his biggest rivals and closest friends, Alexander Dale ...

Alternate approach to traditional CPR saves lives

22 hours ago

A new study shows that survival and neurological outcomes for patients in cardiac arrest can be improved by adding extracorporeal membrane oxygenation (ECMO) when performing cardiopulmonary resuscitation (CPR). The study ...

User comments