The Good, the Bad and the Unknown: The Current State of CV Interventions in Women

Issue: July/August 2016

In the past decade, there have been tremendous advancements in the field of interventional cardiology. Newer-generation coronary stents have reduced rates of stent thrombosis and restenosis. Structural interventions have offered therapy to patients who were once deemed too high risk for surgical intervention.

As the field has advanced, it has become apparent that differences in indications, technique and outcomes for certain interventions may be influenced by gender. This is in line with known differences in cardiac risk factors and presentation of ACS in women compared with men. As technologies continue to rapidly advance, it is important to understand potential differences based on sex. This new column aims to highlight a few of the known differences as well as areas for future study.

TAVR

As the number of transcatheter aortic valve replacement procedures has rapidly increased during the past few years, recent analysis from the PARTNER trial has shown that although immediate postprocedure bleeding complications appear to be higher in women, mortality at 1 year is lower compared with men, regardless of transfemoral or transradial access. This is in contrast to historical literature noting increased mortality risk for women in open surgical AVR. These differences may be attributable to smaller annular size with less residual paravalvular leak. What does this mean for women with aortic stenosis? The data for at least equivalency and possible superiority of TAVR to open AVR in intermediate-risk patients with the newest Sapien 3 device (Edwards Lifesciences) continue to emerge. It may be that the threshold to perform TAVR vs. open AVR in women should be lower; however, further sex-specific analyses are needed to assess potential differences in indication by sex.

PCI

Since the introduction of coronary stent technology in the modern era of interventional cardiology, advancements in stent design and drug elution have made PCI increasingly safe. Although rates of restenosis and stent thrombosis have decreased significantly, the introduction of bioresorbable scaffolds (BRS) holds the potential promise of further reducing long-term complications. The first fully bioresorbable scaffold received FDA approval in July.

Studies have shown that BRS made of poly-L-lactic acid are fully degraded after 3 years, leaving the vessel in its native state. However, the enthusiasm for these new stents has been somewhat tempered by concerns over increased difficulty in stent delivery due to thicker struts, as well as concern for potential increase in stent thrombosis. An intriguing question is whether indications and long-term outcomes with BRS may differ by sex. Women tend to have smaller coronary vessel diameter, which may preclude implantation of these devices because stent diameter sizing is limited. However, an advantage of this type of stent is that once the scaffold is gone, there is return of native vasomotor function. This characteristic is particularly interesting in women, who can often have endothelial dysfunction. Additionally, there have been limited case reports of use of BRS to treat spontaneous coronary artery dissection. Although not a major indication for PCI, spontaneous dissection tends to occur more in young women who may benefit from absorption of the scaffold and avoid the potential long-term complications from residual metallic scaffold left behind by traditional drug-eluting stents. Whether BRS technology overall may be beneficial in women is unknown; however, it deserves further study.

ACS

Despite advancement in technologies, inherent differences in recognition and timely treatment of women presenting with ACS remain. The recently published VIRGO study assessed outcomes in patients presenting with STEMI. The results demonstrated that young women were more likely to have delays in treatment compared with young men. Similar findings were noted in a meta-analysis of STEMI data from more than 20 countries. It has been thought that these delays are attributable to multiple factors, including delay in initial presentation after onset of symptoms, as well as underappreciation of atypical symptoms as angina equivalents in women. These studies highlight the need for further education such that the differences in ACS presentation between men and women are more widely recognized.

References:
D’Onofrio G, et al. Circulation. 2015;doi:10.1161/CIRCULATIONAHA.114.012293.
Haimi I, et al. Gender disparities in ST-elevation myocardial infarction care and outcomes: A global systematic meta-analysis of 731,213 patients. Presented at: Cardiovascular Research Technologies; Feb. 20-23, 2016; Washington, D.C.
Kodali S, et al. Ann Intern Med. 2016;doi:10.7326/M15-0121.
Thourani VH, et al. Lancet. 2016;doi:10.1016/S0140-6736(16)30073-3.

For more information:
Ki Park, MD, MS, FSCAI, is an assistant professor in interventional cardiology at University of Florida and Malcom Randall VA Medical Center, Gainesville. She can be reached at ki.park@medicine.ufl.edu.

Disclosure: Park reports no relevant financial disclosures.