By Trevor Stokes
NEW YORK (Reuters Health) - A significant number of U.S. patients with irregular heart rhythms do not receive adequate therapy, according to a new study of treatment practices for atrial fibrillation.
"Many patients out there that aren't treated probably should be treated," said lead author Dr. Benjamin Steinberg, a fellow at Duke University Medical Center's Duke Clinical Research Institute.
Atrial fibrillation is the most common form of irregular heartbeat, affecting an estimated 2.7 million people in the U.S., according to the Centers for Disease and Control and Prevention.
Symptoms include shortness of breath, fatigue, heart racing and chest pains. Because atrial fibrillation causes irregular blood flow, the disease can also lead to clots that increase the risk of stroke.
If the heartbeat is likened to a drum beat, doctors typically take care of either the quality of the rhythm or its tempo.
"In general, physicians are left to their own devices whether they think the patient will benefit by being put into normal rhythm as opposed simply treating the heart rate," Steinberg told Reuters Health.
Doctors also use blood thinners to reduce the longer-term risk of stroke.
Steinberg's team used a registry of 10,061 U.S. patients treated for atrial fibrillation between 2010 and 2011 and concluded that patients were being under-treated for heart rhythm and stroke.
Two out of three patients received therapies meant to help control their heart rate (6,859 patients or 68 percent). But just one in three patients received treatments meant to control their heart rhythm (3,202 patients or 32 percent).
The patients whose heart rate was controlled tended to be older and sicker, researchers found. Patients who received rhythm control tended to show more symptoms, though other patients might have benefited from the treatment, the researchers said.
The study was published in the American Heart Journal.
"This shows that we are probably underutilizing rhythm control," said Dr. Rod Passman, cardiology professor at Northwestern University's Feinberg School of Medicine, who was not involved in the research.
Controlling a patient's heart rate is relatively simple and includes well-known drugs such as beta-blockers, but may not resolve the irregular heart beat in the long term.
However, controlling a heart's rhythm is trickier since it requires more sophisticated heart monitoring and drugs that can cause severe side effects.
"Rhythm control is very challenging," Passman told Reuters Health. "Many internists and cardiologists are scared of these (rhythm control) medications as well they maybe should be."
Even more troubling for experts: one in four atrial fibrillation patients did not receive blood thinners meant to lower the long-term risk of strokes caused by blood clots.
"This was sobering news; it shows us that in general that anti-coagulation is not being used as much as it should be," Passman said.
For decades, doctors used warfarin, a blood thinner that is affected by certain foods and requires close monitoring of patients. Over the last three years, new blood thinners entered the market that do not require as much monitoring.
Patients at risk for stroke may not receive blood thinners for a variety of reasons, experts said.
Atrial fibrillation can be transient, so patients may not show symptoms during a visit to the doctor's office, which is another potential reason why a doctor might not prescribe blood thinners, experts said.
In addition, frail patients at risk for falls, for example, may not receive blood thinners. Steinberg said in these cases, the risk of bleeding was significantly over-estimated whereas the risk of stroke was significant.
"Perhaps we as providers are over estimating bleeding risk in general and under estimating stroke risk," Steinberg said.
SOURCE: bit.ly/16e9yuk American Heart Journal online February 22, 2013.