Women at greater risk of post-ablation VT recurrence
medwireNews: Women are more likely than men to have recurrent ventricular tachycardia (VT) following ablation, despite having more favourable baseline characteristics, research shows.
The study of 2062 patients (12.9% women) with structural heart disease undergoing ablation at 12 high-volume centres showed that women had a 1-year VT recurrence rate of 30.5%, compared with 25.3% among men, a difference that was statistically significant.
This was in spite of the fact that, on average, women were younger then men and had higher left ventricular ejection fraction, less VT storm and a lower prevalence of comorbidity including atrial fibrillation, diabetes and hypertension.
David Frankel (University of Pennsylvania, Philadelphia, USA) and co-authors of the study say that difference was only partially explained by a higher prevalence of nonischaemic cardiomyopathy (NICM) in women than men (69.2% vs 43.7%).
In unadjusted analyses, women had a significant 30% increased risk of recurrence within 1 year compared with men, which increased to 46% after adjustment for left ventricular ejection fraction and prevalence of VT storm. Further adjustment for NICM along with inducibility of clinical VT at the end of ablation, which was also higher in women, attenuated the risk to 32%, but this was still statistically significant.
Frankel and team also point out that the greatest difference in VT recurrence was between women and men with ischemic cardiomyopathy, at 31.7% versus 22.8%.
“Thus, it is possible that the arrhythmia substrate in women is more challenging to ablate for reasons not yet understood”, they write in JAMA Cardiology.
The rate of death and transplant did not differ between then women and men (21.4 vs 24.1%) throughout an average 2.1 years of follow-up.
The researchers note that, consistent with other reports, only a small proportion of the VT ablation patients were women. “While women did not seem to be referred at a more advanced stage of disease, it is possible that women perceived to be at highest risk may not be referred for ablation at all but rather treated medically, leading to both underrepresentation of women and the healthier baseline characteristics we observed,” they remark.
The team concludes: “Whether the worse outcome observed in women is owing to referral bias, more challenging arrhythmia substrate or undertreatment requires further study.”
By Laura Cowen
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