Fig. 3.1
Cumulative event rates of target lesion revascularization during 3-years of follow-up (From Stefanini et al. [18])
According to the 2012 guidelines of the American College of Cardiology–American Heart Association for percutaneous coronary interventions, use of drug-eluting stents has a class IA recommendation for patients undergoing elective percutaneous revascularization who are able to adhere to a prolonged regimen of dual antiplatelet therapy (DAPT). However, the 2014 ESC guidelines for revascularization recommend DAPT for 6 months after DES implantation (class IB). More details in this regard are given in Chap. 6 of this book. The risk of stent thrombosis has become exceedingly low and no longer represents a limitation to the use of drug-eluting stents [19].
Lesion length remains a predictor of target lesion revascularization and results of long lesion stenting remain poor. The ADVANCE study was the first to demonstrate that stenting in long lesions (>40 mm) was associated with higher MACE rates. Sirolimus-eluting stents (SES) have been shown to yield superior results to paclitaxel-eluting stents in most, but not all studies. At 9-months and 1-year, outcomes of Biolimus biodegradable polymer (BES) and sirolimus permanent polymer stents (SES) in long lesions (>20 mm) appear similar with respect to MACE in long lesions in this “all-comer” patient population (1707 patients) included in the LEADERS sub-study. However, long lesions tended to have a higher rate of binary in-segment restenosis and target lesion revascularization (TLR) following BES than SES treatment. Similar results for BES and SES have been observed in small diameter vessels (<2.75 mm). There were no differences in MACE and TLR rates for both stent types [20].
The Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation (COURAGE) trial published in 2007 and the Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) trial published in 2009 failed to show a benefit of PCI over optimal medical therapy for the prevention of death or MI in patients with SIHD. Data from the COURAGE trial suggest that the benefits of optimal medicament therapy (OMT) alone in comparison with OMT plus PCI were similar for men and women. Moreover, the outcomes of revascularization appeared to be less favorable among women than men although very few women were enrolled in COURAGE (15 % of patients).
3.6 Coronary Artery Bypass Grafting
Women who undergo coronary artery bypass grafting (CABG) are less likely to receive a mammary graft and have more incomplete revascularization, greater bleeding, and mortality compared with men. Regarding endovascular and surgical treatment of CAD, intervention in women has some distinct features. Fisher LD et al. in 1982 published data from the Coronary Artery Surgery Study (CASS). They studied association of sex, physical size, and operative mortality after coronary artery bypass in the Coronary Artery Surgery Study (CASS). The study showed that women after coronary artery bypass surgery (CABG) had a 4.5 % mortality compared with 1.9 % in men with shorter graft durability, lesser degree of symptom improvement in the postoperative period, frequent postoperative myocardial infarction, more frequent heart failure occurrence, and were more likely to require reoperation within 5 years after CABG. The study investigators concluded that physical size of the patient, including coronary artery diameter, helps predict operative mortality even after adjusting for differences in risk predicted by the basic variables and gender. However, patient’s gender is not statistically significantly related to the risk of surgical death given the information available from clinical and angiographic variables and from knowledge of patient size. The explanation for the excess risk associated with coronary artery operations in women in this study was the smaller stature and the smaller diameter of the coronary arteries in this group of patients [21]. Abramov et al. [22] published data showing that women have a higher risk of morbidity and mortality and experience less relief from angina than do men after CABG, despite accounting for less than 30 % of the CABG population. Interestingly, this sex discrepancy appears to be reduced when an off-pump CABG is performed [23].
These first trial results raised the issue of CABG safety in women and initiated the conduction of several newer trials. Studies were carried out to evaluate short- and long-term mortality in women who undergo coronary artery bypass grafting (CABG). Results for these were conflicting. Recently, investigators conducted a meta-analysis of all existing studies to evaluate the impact of female gender on mortality in patients who undergo isolated CABG. A comprehensive search of studies published through May 31, 2012 identified 20 studies comparing men and women who underwent isolated CABG. All-cause mortality was evaluated at short-term (postoperative period and/or at 30 days), midterm (1-year), and long-term (5-year) follow-up. A total of 966,492 patients (688,709 men [71 %] and 277,783 women [29 %]) were included in this meta-analysis. Women were more likely to be older; had significantly greater comorbidities, including hypertension, diabetes mellitus, hyperlipidemia, unstable angina, congestive heart failure, and peripheral vascular disease; and were more likely to undergo urgent CABG (51 vs. 44 %, p <0.01). Short-term mortality (OR 1.77, 95 % CI 1.67–1.88) was significantly higher in women (Fig. 3.2).
Fig. 3.2
Association of female gender with short-term mortality (composite of postoperative or 30-day mortality) (From Alam et al. [24])
At midterm and long-term follow-up, mortality remained high in women compared with men (Figs. 3.3 and 3.4).
Fig. 3.4
Association of female gender with long-term follow-up 5-year mortality after isolated CABG (From Alam et al. [24])
Women remained at increased risk for short-term mortality in two subgroup analyses including prospective studies (n = 41,500, OR 1.83, 95 % CI 1.59–2.12) and propensity score-matched studies (n = 11,522, OR 1.36, 95 % CI 1.04–1.78). In conclusion, investigators observed that women who underwent isolated CABG experienced higher mortality at short-term, midterm, and long-term follow-up compared with men. Mortality remained independently associated with female gender despite propensity score-matched analysis of outcomes [24]. Several explanations for this observation have been proposed such as the delayed reference of women to CABG when CAD extends to a greater degree, the smaller size of women coronary vessels that creates technical issues to the surgeon, or finally the limited use of left internal mammary artery in women [11].
Arterial Revascularization Therapies Study Part I (ARTS I) was one of the studies which compared gender-related differences following coronary revascularization procedures (CABG and PCI with BMS). The study demonstrated that for a total of n = 1205 patients included in time from 1997 to 1998, there was no significant difference in terms of death, stroke, or myocardial infarction between the two genders. However, stenting was associated to a greater need for repeated revascularization. There was a similar early- and long-term outcome between female and male subjects. The only difference observed was an increased risk of bleeding complications in women treated with PCI. In both genders of the ARTS I population, treatment with CABG was associated with a lower incidence of MACCE (death, CVA, MI, CABG, RPCI) compared to PCI at 5 years. Vaina et al. [25] published data of a multicenter nonrandomized open label study, Arterial Revascularization Therapies Study Part II (ARTS II), that was designed to evaluate the outcomes of sirolimus-eluting stent implantation in comparison to BMS implantation and CABG in patients with multivessel CAD from ARTS I. In ARTS II were included a total of n = 605 patients during year 2003. The study showed that the overall MACCE rate at 1 year was similar to that of the ARTS I – CABG arm and significantly reduced when compared to the ARTS I – PCI arm (Fig. 3.5). Additionally, it was observed that both genders had a more favorable clinical outcome with sirolimus-eluting stents compared with BMS but similar to CABG. These results could potentially institute PCI as the first choice treatment in women with multivessel disease.
