Previous studies have shown a relation between female gender and adverse outcomes after percutaneous coronary intervention (PCI). The aim of this study was to determine whether there are differences in correlates between genders for these long-term adverse outcomes in patients with acute coronary syndromes. Gender differences were evaluated in the clinical outcomes of 6,929 consecutive patients with acute coronary syndromes from a large, contemporary PCI registry. Rates of major adverse cardiovascular events, defined as all-cause mortality, myocardial infarction, and target lesion revascularization at 1-year follow-up, are reported. Independent correlates of adverse outcomes were identified using multivariate proportional-hazards regression analysis. Women were older (p <0.001); had a higher prevalence of diabetes mellitus (p <0.001), systemic hypertension (p <0.001), chronic renal insufficiency (p = 0.02), peripheral arterial disease (p <0.001), and congestive heart failure (p <0.001); had lower body surface areas (p <0.001); and had higher body mass indexes (p <0.001). Acute coronary syndrome presentation in women tended to be unstable angina pectoris with Canadian Cardiovascular Society class III and IV symptoms, whereas men had more acute myocardial infarctions. At 1 year, the unadjusted rates of all-cause mortality (10.7% vs 7.5%, p <0.001) and major adverse cardiovascular events (16.4% vs 12.7%, p <0.001) were higher in women. There was a stark difference between the genders in independent correlates of mortality and major adverse cardiovascular events at 1 year. Moreover, the traditional correlates did not have the same impact in women as in men. In conclusion, although there are differences in clinical outcomes after PCI for women compared with men, there are different correlates for these adverse outcomes. These gender-based differences should be taken into account when women undergo contemporary PCI.
An estimated 43 million women have coronary artery disease, the leading cause of death in women, with about 400,000 deaths annually. Nearly 43% of patients with acute coronary syndromes (ACS) are women; about 360,000 women underwent percutaneous coronary intervention (PCI) in 2007 per American Heart Association statistics. Early studies showed that women who undergo PCI are known to have a higher incidence of adverse outcomes than men. Evaluating clinical outcomes of women after PCI has been challenging. Historically, female gender has been associated with increased complications during and after PCI. Women who undergo PCI usually present with more co-morbid conditions, including systemic hypertension, older age, elevated cholesterol, more complex and diffuse coronary disease, and longer referral times. In the current PCI era, with the use of drug-eluting stents and newer antiplatelet and anticoagulant medications, the gender gap has narrowed with respect to adverse clinical outcomes; however, women with ACS have an increased mortality risk at younger ages compared with men of the same age. European data have shown that over the past 40 years, age-adjusted mortality for cardiovascular deaths in Western countries has decreased, but at the same time, the decrease among women is more modest than among men. Although some studies have identified age, systemic hypertension, diabetes mellitus, renal failure, and peripheral arterial disease (PAD) as independent predictors of 1-year mortality, no study has systemically studied gender-based correlates of long-term cardiovascular outcomes. In the present study, we aimed to evaluate the predictors of 1-year mortality and major adverse cardiovascular events (MACEs) in both genders in a large PCI database and to identify gender-based variables that may help better define the long-term risk in patients with ACS.
To evaluate gender-based differences in clinical outcomes in a large, contemporary PCI registry, we retrospectively analyzed 6,929 consecutive patients presenting with ACS to a single, large, tertiary center from January 2000 to November 2010. The study was approved by the institutional review boards of MedStar Washington Hospital Center and the MedStar Health Research Institute (Washington, District of Columbia). A dedicated data coordinating center performed all data management and analyses. Prespecified clinical and laboratory data during hospitalization periods were obtained from hospital charts reviewed by independent research personnel blinded to the study objectives. Clinical follow-up at 30 days, 6 months, and 1 year was conducted by telephone contact or office visits. The occurrence of major late clinical events was recorded, including death (all-cause), myocardial infarction, revascularization, and stent thrombosis. All clinical events were adjudicated by source documentation by independent cardiologists not involved in the procedures. No imputation method was used to address missing data.
PCI was performed according to guidelines current at the time of the procedure. All patients received aspirin 325 mg and clopidogrel 300 to 600 mg (at the operator’s discretion) before or just after the procedure. Anticoagulation regimens were chosen at the operator’s discretion and included unfractionated heparin targeted to achieve an activated clotting time of 250 to 300 seconds, with or without glycoprotein IIb/IIIa inhibitors, or bivalirudin 0.75 mg/kg followed by an infusion of 1.75 mg/kg/hour for the duration of the procedure. After the procedure, aspirin 81 to 325 mg/day was continued indefinitely, and dual-antiplatelet therapy was recommended for ≥12 months in all patients. All patients routinely underwent 12-lead electrocardiography before and after PCI to detect procedure-related ischemic changes and/or the presence of new pathologic Q waves. Blood samples at 6 and 24 hours before and after PCI were drawn to assess creatine kinase-MB.
Q-wave myocardial infarction was defined as an elevation of creatine kinase-MB ≥2 times the upper normal value in the presence of new pathologic Q waves (>0.4 seconds) in ≥2 contiguous leads on electrocardiography. Non-Q-wave myocardial infarction was defined as typical ischemic chest pain and/or ST-segment and/or T-wave abnormalities with a creatine kinase-MB increase ≥2 times the reference values without any new pathologic Q waves. Target lesion revascularization was defined as clinically driven revascularization of the index lesion. Target vessel revascularization was defined as revascularization occurring in any area along the previously treated vessel. Academic Research Consortium definitions for stent thrombosis were used. PCI angiographic success was defined as a residual stenosis of <30% with Thrombolysis In Myocardial Infarction (TIMI) grade 3 flow. Clinical success was defined as angiographic success in the absence of target lesion revascularization, Q-wave myocardial infarction, or death before hospital discharge. Major bleeding was defined according to the TIMI Study Group definition and consisted of intracranial hemorrhage or clinically overt bleeding with a decrease in hemoglobin ≥5 g/dl or in hematocrit ≥15%. MACEs were defined as death, Q-wave myocardial infarction, and target lesion revascularization. Chronic renal insufficiency (CRI) was defined as medical therapy or dialysis for chronic renal failure or a creatinine level ≥2.0 mg/dl on admission. Procedure-related renal insufficiency was defined as an in-hospital increase in creatinine of ≥0.5mg/dl after the procedure.
Continuous variables are presented as mean ± SD and categorical variables as percentages. Differences in continuous variables between groups were compared using Student’s t test. Proportions were compared using chi-square or Fisher’s exact tests as appropriate. A p value <0.05 was considered statistically significant. Independent correlates of adverse outcomes were identified using multivariate proportional-hazards regression analysis. Statistical analyses were performed using SAS version 9.1 (SAS Institute Inc., Cary, North Carolina).