Forget Mars and Venus, Men and Women Are From the Same Planet After All

With over 1 million percutaneous coronary interventions (PCI) performed in the United States annually, nearly one-third of these procedures are performed in women.¹ Female patients with cardiovascular disease (CVD) tend to have a higher risk profile by the time they are referred for PCI. They are often older with more comorbidities, including diabetes and hypertension.^2-4 Earlier studies examining gender-specific outcomes following PCI demonstrated higher rates of mortality in women,^5,6 thought to be related to their smaller coronary vessel diameters and higher rates of coronary artery dissection and access-site vascular complications.^7,8 This gender gap has narrowed with time since the stenting era, and more recent studies have failed to show any differences in post-PCI outcomes between both genders.^2,8-11

In the current issue of the Journal of Invasive Cardiology, Shammas et al¹² examined the differences in long-term target vessel failure (TVF) rates between men and women undergoing PCI with a zotarolimus-eluting stent (ZES). The authors performed a retrospective analysis of a cohort of 197 consecutive patients (133 male and 64 female) who had been treated with a ZES and demonstrated no statistically significant difference in TVF (the combined endpoint of  cardiac death, non-fatal myocardial infarction and target vessel revascularization) rates at 2 years between men and women (22.6% vs 32.8%; P=.684); cardiac death and target vessel revascularization rates were also numerically higher in female patients, but were not statistically significant. In the cohort of 122 patients whose angiographic films were independently reviewed, no significant gender-related difference was demonstrated in lesion severity and procedural characteristics. Multivariate analysis failed to demonstrate female gender as an independent predictor of TVF (odds ratio, 2.21 [OR]; 95% confidence interval [CI], 0.89-5.47). Despite the small sample size, the study appears to be consistent with prior studies examining gender-specific differences following drug-eluting stent (DES) placement in PCI.

A recently published meta-analysis by Stefanini and colleagues evaluated gender differences in a population pooled from three large randomized trials using DES for coronary artery revascularization (sirolimus-eluting versus paclitaxel-eluting stents for coronary revascularization [SIRTAX]; biolimus-eluting stent with biodegradable polymer versus sirolimus-eluting stent with durable polymer for coronary revascularization [LEADERS]; zotarolimus-eluting versus everolimus-eluting coronary stents [RESOLUTE All-Comers]).³ In this pooled analysis of more than 5000 patients, the authors found that women undergoing PCI are usually older and have more cardiovascular risk factors but a lower degree of angiographic complexity. At 2-year follow-up and after controlling for baseline differences, women undergoing PCI with DES had similar outcomes compared to male patients (Figure 1). There was no difference in rates of cardiac death, myocardial infarction, target lesion revascularization, target vessel revascularization, stent thrombosis, in-stent late loss, or in-segment binary restenosis (Figure 2).³ Prior to this study, the “TAXUS Woman” analysis, which included more than 3000 female patients, showed that women have similar benefits from paclitaxel-eluting stents compared to men, except in high-risk patients, in which women had slightly higher TLR rates.⁴ This was clearly exemplified in other studies that looked at high-risk populations undergoing PCI. In patients with ST-elevation myocardial infarction undergoing primary PCI, female patients had a 2-fold higher rate of mortality than men.¹³ In dialysis-dependent patients undergoing PCI, female gender was independently associated with significantly higher rates of in-hospital mortality (OR, 13.23; 95% CI, 1.55-113.25) and adverse cardiac events (OR, 7.41; 95% CI, 1.81-30.27).¹⁴

Moreover, gender discrepancies in referral for coronary angiography seen in earlier studies of acute coronary syndrome (ACS) patients¹⁵ still exist, with recent data from the Minnesota Heart Survey demonstrating that women with a myocardial infarction (MI) were 27% less likely to undergo cardiac catheterization than their male counterparts (OR, 0.73; 95% CI, 0.57-0.94).¹⁶ Despite lower angiography referral rates in women, revascularization rates are not significantly different between genders. Men, however, are more often referred for surgical revascularization while women, who are more prone to single-vessel disease, are more likely to undergo PCI.^16,17

Examination of gender-related disparities among cardiovascular patients is difficult as women continue to be underrepresented in clinical trials. The majority of these analyses have shown that women usually present at a more advanced age, with a greater prevalence of high-risk features such as diabetes and hypertension which are usually responsible for a worse outcome. However, after adjustment for these differences in baseline characteristics, outcomes for male and female patients have proven to be similar, albeit the limitations that these statistical analyses may have. While recent literature has suggested closure of the gender gap, high-risk female patients undergoing PCI still suffer worse outcomes than their male counterparts. Randomized cardiovascular trials designed to study sex-specific differences in outcomes are warranted.

References

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17. Khawaja FJ, Rihal CS, Lennon RJ, Holmes DR, Prasad A. Temporal trends (over 30 years), clinical characteristics, outcomes, and gender in patients ≤50 years of age having percutaneous coronary intervention. Am J Cardiol. 2011;107(5):668-674.

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From the Department of Medicine, Division of Cardiovascular Diseases, Stony Brook University Medical Center, Stony Brook, New York.
Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. The authors report no conflicts of interest regarding the content herein.
Address for correspondence: Luis Gruberg, MD, FACC, Department of Medicine, Division of Cardiovascular Diseases, Health Sciences Center, T16-080, Stony Brook, NY 11794-8160. Email: luis.gruberg@stonybrook.edu