A therapy to prevent heart failure is twice as effective in women as in men. It’s the first time that a heart treatment has been shown to offer greater benefit to women.

The effectiveness of cardiac resynchronization therapy with defibrillator (CRT-D) in 1,820 patients, CRT-D combines the benefits of both an Implantable Cardioverter Defibrillator (ICD) and cardiac resynchronization therapy. ICDs prevent sudden, irregular rhythm-related cardiac death, and resynchronization therapy boosts heart function and reduces the risk of heart failure and related symptoms.

CRT-D is approved in the United States to treat patients with severe heart failure and those with mild heart failure to prevent them from progressing to advanced heart failure. The CRT-D device was developed by Boston Scientific.

Among women, CRT-D led to a 70 percent reduction in heart failure and a 72 percent reduction in death. Among men, the treatment led to a 35 percent reduction in heart failure. It’s not that men did poorly in the trial, but rather, women had really fantastic results, likely due to the type of heart disease we see more commonly in women.

The women in the study were more likely to have non-ischemic heart disease, which is usually characterized by inflammatory scarring of the heart muscle. Men were more likely to have ischemic heart disease, which occurs when narrowed arteries restrict the flow of blood and oxygen to the heart.

In addition, more women had left bundle branch block, a condition that causes disorganized electrical activity throughout the heart. The two types of heart disease that were more common among women are more likely to respond to CRT-D.