An analysis from the US Get with the guidelines for heart failure (GWTG-HF) registry has found that women and men with heart failure and reduced left ventricular ejection fraction benefit similarly from implantable cardioverter defibrillators (ICDs).
“Despite current guidelines recommending that health care practitioners consider adding these devices to standard heart failure treatments in both women and men, women with heart failure have been less likely to receive defibrillators. These new data reinforce the existing gender-neutral guidelines,” says Emily Zeitler from Duke Clinical Research Institute in Durham, USA, and lead author of the study recently published in Circulation: Heart Failure.
Randomised controlled trials have shown that patients with heart failure live significantly longer if they have an ICD implanted for primary prevention. However, because the trials enrolled relatively few women, whether women benefited from ICDs was still an open question. In the analysis, Zeitler et al comment that “ethical challenges make it unlikely that there will ever be a trial of primary prevention ICDs in women”; however, they add, two meta-analyses have assessed the impact of primary prevention ICDs on survival in women, only one of those demonstrated benefit and some other post-hoc and observational analyses have shown mixed results. Therefore, in this propensity score-matched analysis, the authors sought to examine clinical practice data to compare survival rates among women with heart failure with or without a primary prevention ICD.
Using data submitted to Medicare from 264 US hospitals included in the GWTG-HF registry, the researchers compared survival in 430 heart failure women with reduced left ventricular ejection fraction who received preventive ICDs versus 430 matched women with very similar characteristics but no ICDs. Then, the authors compared women with similar matched analyses among 859 men who received an ICD and 859 who did not.
Zeitler et al found that after a median follow-up of 3.4 and three years, respectively, for the propensity-matched groups of women with and without and ICD, the overall risk of mortality was significantly lower in women with the device (40.2%) compared with 48.7% of women without an ICD. They note that a similar survival benefit was observed after a median follow-up of 3.9 and three years, respectively, among the propensity-matched groups of men with an ICD (42.9%) compared with 52.9% of men without it.
The authors also found that, in both men and women with an ICD, the risk of death was more than 20% lower after about three years.
In conclusion, Zeitler et al write: “Both women and men implanted with a primary prevention ICD during or after a heart failure hospitalisation had significantly longer survival than their counterparts who did not receive and ICD, and there were no significant sex-based interactions for the survival benefits associated with ICD placement…These data support current guideline recommendations for the implantation of a primary prevention ICD in eligible women and men with heart failure and reduced left ventricular ejection fraction.”
They also note that although this analysis and others demonstrate a mortality benefit for women from a primary prevention ICD, this benefit must be weighed against potential risks. “This is particularly important for women because complication rates associated with primary prevention ICD implantation tend to be higher than men. Future research is needed to identify ways to reduce complication rates to maximise the net benefit from primary prevention of ICDs in women,” they write.
The Agency for Healthcare Research and Quality funded the study.