Beta blockers, the cornerstone therapy for left-side heart failure, can improve pulmonary arterial hypertension, a small study indicates.
The results suggested that the therapy could help prevent right-side heart failure, the leading cause of death among PAH patients.
The study, “Pulmonary arterial hypertension treatment with carvedilol for heart failure: a randomized controlled trial,” was published in the Journal of Clinical Investigation (JCI).
Dysfunction of the right ventricle, or heart chamber, is the underlying cause of right-side heart failure. The dysfunction can progress independently of increases in patients’ blood pressure, which remains the target of most PAH therapies. This means that the underlying cause of heart failure is unaddressed in most PAH patients.
“In contrast to the lack of RV-targeted [right-ventricular-targeted] therapy for the heart failure of PAH, left ventricular–targeted (LV-targeted) therapy has been the foundation of left-sided or global heart failure for nearly 40 years,” the researchers wrote. The left-side heart treatment approach is called beta-adrenergic receptor blockade, and the therapies are commonly known as beta blockers.
While beta blockade is an approved therapy for left ventricle dysfunction and heart failure, its ability to address right ventricle dysfunction had not been thoroughly tested until an Ohio research team decided to do it. Some previous studies had actually suggested that it decreased lung function.
The team randomly assigned patients to carvedilol or a placebo for six months. Carvedilol was administered either as a low fixed dose or as escalating doses.
Carvedilol led to drops in patients’ heart rate and blood pressure. It also improved their heart rate recovery from exercise, and did not lead to airflow deterioration or worsen their heart condition.
The results suggested that carvedilol improves heart function, an indication that it could prevent right-side heart failure.
“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,” Dr. Serpil C. Erzurum, chair of Cleveland Clinic’s Lerner Research Institute, said in a press release. “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,” said Erzurum, the study’s lead author.
Dr. W. H. Wilson Tang, an advanced heart failure and transplant cardiologist at Cleveland Clinic and a study co-author, added: “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.”