Beta Blocker Shows Promise in Treatment of Pulmonary Arterial Hypertension
A common beta blocker appears safe to use in pulmonary arterial hypertension patients with evidence of improved outcomes that could prevent right-sided heart failure. A study said carvedilol should no signs of decreasing function lung capacity. Here are more details.
CLEVELAND -- Pulmonary arterial hypertension (PAH) is a progressive disease which usually leads to right-sided heart failure and death within five to seven years of diagnosis.
A new study has found that a common drug, already in the heart disease arsenal, shows promise for treating the serious condition.
published in the journal JCK Insight points out that right ventricular dysfunction occurs separately from increased blood pressure but that currently approved PAH treatments focus on pulmonary vessels rather than cardiovascular dysfunction.
At the same time, Cleveland Clinic-led researchers emphasize that left-sided heart failure therapy has targeted left ventricular dysfunction for decades, often using beta-adrenergic receptor blockade, better known as beta blockers, to improve left ventricular function.
"There is a critical need for new therapies to support right ventricular function in pulmonary hypertension," explained lead author Serpil C. Erzurum, MD, chair of Cleveland Clinic Lerner Research Institute. "While treatments with beta blockers such as carvedilol are standard therapy in patients with left-sided heart failure, successful therapies in right-sided heart failure and PAH have lagged behind. Longer-term studies are needed but our initial analysis shows that carvedilol may also benefit patients with PAH, who currently have few available treatment options."
In a small double-blind, randomized study, the researchers assessed carvedilol use in 30 PAH patients, with participants receiving either placebo, low fixed-dose, or escalating doses of carvedilol over a six-month period.
Results indicate that the beta blocker lowered heart rate in sync with dosage and improved heart rate recovery from exercise without worsening heart failure or leading to airflow deterioration.
The result, according to study authors, is that carvedilol appears safe to use in PAH patients for six months with evidence of improved outcomes that could prevent right-sided heart failure. Concerns about decreased functional lung capacity limited studies of the use of beta blockers in PAH patients, they add.
"There is good reason to consider beta blockers for the right ventricular failure in PAH," noted co-author W. H. Wilson Tang, MD, advanced heart failure/transplant cardiologist at Cleveland Clinic. "The fact that beta blockers were well-tolerated and effective in lowering heart rates thereby improving the heart efficiency is unto itself a key observation, since doctors have been cautioned against using them in this setting for safety concerns. This study provides important new data that advances our knowledge of using this class of drugs in this chronic and life-threatening lung-associated vascular disease."