Cardiac resynchronization therapy with defibrillator (CRT-D) is a class of implantable medical devices that help the heart in maintaining its rhythm. 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. A recent study revealed that CRT-D therapy is two fold more effective in women as compared to men in preventing heart failure.
CRT-D device provides cardiac resynchronization therapy by generating small electrical impulses that coordinate the action of the right and left heart ventricles so that they work together more effectively. The defibrillator function senses dangerous heart rhythm abnormalities and provides an electrical shock to restore the heart back to a normal rhythm.
About the study
The study was conducted by Dr. Arthur J. Moss, a professor of medicine at the University of Rochester Medical Center and his colleagues. The researchers evaluated the effectiveness of CRT-D in 1,820 patients in Canada, Europe and the United States. Boston Scientific, developer of CRT-D, partnered in the study. The study was published in Feb. 7 issue of the Journal of the American College of Cardiology.
The study revealed that CRT-D led to:
- 70% reduction in heart failure in women as compared to 35% in men
- 72% reduction in death in women
The most striking fact about the study is that it establishes greater benefit in heart treatment of women for the very first time. Dr. Moss added that “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.”
src="http://www.knowabouthealth.com/wp-content/uploads/2011/02/ht_health_reform_doctor_helping_elderly_patient_0210_01.jpg" alt="" width="241" height="200" />Why would women show better response to CRT-D therapy?
We know there are some physiological and biological differences between men and women. The researchers attributed the effectiveness difference between in men and women to type of heart disease. The leading hypothesis is that the women in the study were more likely to have non-ischemic heart disease, where as men more likely to have ischemic heart disease. The non-ischemic disease is characterized by inflammatory scarring of the heart muscle, where as ischemic disease is characterized by presence of narrowed arteries that restrict the flow of blood and oxygen to the heart.
Also, it has been observed that a condition called left bundle branch block was more prevalent in women. This condition causes disorganized electrical activity throughout the heart, which can be taken care of by using CRT-D.
I think this is a good finding for women and the medical device industry. The device industry has fought hard to prove that CRT-D is beneficial for type I, Type II (mild heart diseases) and Type III and Type IV (severe heart diseases) heart failure patients. This study would enhance acceptance of CRT-D therapy. Happy Heart awareness month!