Source: Jamanetwork

Women may benefit more from CRT-D therapy than men


Women may benefit more from CRT-D therapy than men

Cardiac resynchronization therapy (CRT) which uses pacemakers to improve coordination of heartbeats, are more likely to benefit women than men, according to new data published in the New England Journal of Medicine.

The analysis included patients with left bundle-branch block and saw a 60 % reduction in women’s risk of heart failure or death. Risk of death was reduced by 55 percent.

“Overall, this study highlights the importance of sex-specific analysis in medical device clinical studies and the public health value of combining individual-patient data from clinical trials submitted to the FDA,” said the authors.


  • Women benefitted more than men and the main difference came in patients with LBBB and a QRS of 130 to 149 milliseconds. In this group, women had a 76 percent reduction in heart failure (absolute difference 23%) or death and a 76 percent reduction in death alone (absolute difference 9%), but there was no significant benefit in men.
  • Neither sex benefitted from CRT-D at QRS shorter than 130 milliseconds and both sexes benefitted at QRS of 150 milliseconds or longer.
  • The finding is important because recent guidelines limit the class I indication for CRT-D to patients with LBBB and QRS of 150 milliseconds or longer.


In an invited commentary, C. Noel Bairey Merz, MD, of the Cedars Sinai Heart Institute, Los Angeles, California and Vera Regitz-Zagrosek, MD, of Charite University Medicine, Berlin said: “These results also shed light on a major contributor to the misdiagnosis and suboptimal treatment of CVD in women: guidelines are typically based on a male standard and do not address important differences in women. … Women remain the minority of research subjects but the majority of persons dying from CVD.”


For more information on the story visit:

Bairey Merz CN. JAMA Intern Med.2014;doi:10.1001/jamainternmed.2014.320.   

Zusterzeel R. JAMA Intern Med.2014;doi:10.1001/jamainternmed.2014.2717.