Mortality varies by gender in those with heart failure, ICD

0 Comments | Family Practice News, Oct 1, 2009 | by Mary Ann Moon

Implantable cardioverter defibrillators do not reduce all-cause mortality in women who have advanced heart failure, unlike in men, according to a meta-analysis.

"In other words, ICDs are being implanted in hundreds of thousands of women without substantial evidence of benefit, apparently based on the assumption that, to paraphrase the old saying, "What's good for the gander is good for the goose,'" Dr. Rita F. Redberg said in an editorial comment accompanying the report.

This finding is particularly concerning because a "recent analysis of the National Cardiovascular Data Registry found that women have a 70% higher risk of major adverse events after ICD implantation than do men," noted Dr. Redberg, editor of the journal and director of women's cardiovascular services at the University of California, San Francisco.

Dr. Hamid Ghanbari and his associates at Providence Hospital Heart Institute and Medical Center, Southfield, Mich., performed the meta-analysis because most of the patients in clinical trials of ICDs have been male. It has never been established whether women with advanced heart failure receive the same benefit from ICD placement for the primary prevention of sudden cardiac death.

The investigators pooled data from five randomized, controlled clinical trials that compared ICD implantation with medical therapy and included 934 women along with 3,810 men. Men who had heart failure with reduced left ventricular ejection fraction showed a significant decrease in all-cause mortality when they were given an ICD rather than medical therapy to prevent sudden cardiac death.

In contrast, women did not show a mortality benefit, either in the combined data or in any of the five individual trials, Dr. Ghanbari and his colleagues said (Arch. Intern. Med. 2009;169:1500-6).

The reason for this discrepancy is not yet known, and further study of the issue is warranted. One possible explanation is that women who receive ICDs are known to have more severe comorbidities than men who receive them, and thus may have more competing causes of death compared with men, the researchers said.

In her editorial comment, Dr. Redberg concurred that further study of this surprising finding is warranted (Arch. Intern. Med.2009;169:1460-1).

Neither Dr. Ghanbari nor Dr. Redberg reported any financial conflicts of interest.