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Young women are usually protected against coronary artery disease due to hormonal and risk-factor profile. Previous studies have suggested poorer outcome in women hospitalized with acute coronary syndrome as compared with men. However, when adjusted for age and other risk factors, this difference does not remain significant. We compared the risk profile and outcome between young (≤55 years) women and men admitted with acute coronary syndrome.
Methods
We analyzed clinical characteristics, management strategies, and outcomes of men and women ≤55 years of age enrolled in the biennial Acute Coronary Syndrome Israeli Surveys between 2000 and 2013.
Results
Among 11,536 patients enrolled, 3949 (34%) were ≤55 years old (407 women, 3542 men). Women were slightly older (48.9 ± 5.7 vs 48.3 ± 5.5, P = .007) and suffered more from diabetes (34% vs 24%) and hypertension (47% vs 37%, P <.001 for both). Rates of prior myocardial infarction were high in both sexes (18% vs 21%). Women presented less often with ST-elevation myocardial infarction (50% vs 57%, P = .007) and with typical chest pain (73% vs 80%, P = .004), and had higher rates of Global Registry of Acute Coronary Events (GRACE) score ≥140 (19% vs 12%, P = .007). After adjustment for GRACE score, diabetes, and enrollment year, women had a lower likelihood to undergo coronary angiography during hospitalization (odds ratio 0.6, P = .007). Female sex was independently associated with higher risk of in-hospital mortality (hazard ratio [HR] 4.1; 95% confidence interval [CI], 1.15-14.0), 30-day major adverse cardiac and cerebral events (HR 2.1; 95% CI, 1.31-3.36), and 5-year mortality (HR 1.96; 95% CI, 1.3-2.8).
Conclusions
Young women admitted with acute coronary syndrome are a unique high-risk group that presents a diagnostic challenge for clinicians. Women receive less invasive therapy during hospitalization and have worse in-hospital and long-term outcomes.
In young patients with acute coronary syndrome (ACS), female sex was independently associated with 4.1-fold higher risk of in-hospital mortality, 2.1-fold risk for 30-day major adverse cardiac and cerebrovascular events, and 1.96-fold higher risk for 5-year mortality.
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Young women with ACS are a unique high-risk group that presents a diagnostic challenge for clinicians.
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Women receive less invasive therapy during hospitalization and have worse in-hospital and long-term outcomes.
Premature presentation of ischemic heart disease has become increasingly common. According to recent reports, patients younger than 55 years account for 23% of all patients with acute coronary syndrome.
of cases. Studies have consistently shown that the unadjusted outcome of women following acute coronary syndrome is significantly worse as compared with men. However, this disparity in risk for mortality was greatly attenuated after adjustment for age, comorbidities, and other confounders.
Most of these data predate the era of early invasive approach, modern antiplatelet therapy, and other current standard-of-care medications. Despite some increase in the awareness to acute coronary syndrome in women, many studies still show a tendency toward conservative rather than invasive therapy in women,
Bridging the gender gap: Insights from a contemporary analysis of sex-related differences in the treatment and outcomes of patients with acute coronary syndromes.
a fact that may affect outcome in this population. In addition, most studies examined short-term outcomes. Therefore, we aimed to study sex-related differences in the management and outcome of young (≤55) patients with acute coronary syndrome in an all-comer, contemporary national cohort.
Methods
Acute Coronary Syndrome Israeli Surveys
Acute Coronary Syndrome Israeli Surveys (ACSIS) is a national acute coronary syndrome survey conducted in all 25 cardiology departments in Israel since 1992. Details of these nationwide surveys have been previously reported.
Briefly, ACSIS is a 2-month nationwide survey conducted biennially, which prospectively collects data from all acute coronary syndrome admissions in each of the 25 coronary care units and cardiology wards operating in Israel. Prespecified, standard forms were used to record demographic, clinical data management and outcome during the index hospital stay and subsequent follow-up. Admission and discharge diagnoses were recorded as determined by the attending physicians based on clinical, electrocardiographic, and biochemical (elevated creatine kinase-MB or troponin levels) criteria. Definitions of type of myocardial infarction (ST-elevation myocardial infarction vs non-ST-elevation myocardial infarction) and unstable angina were homogeneous and based on prespecified criteria according to accepted definitions in the specific survey period.
Myocardial infarction redefined–a consensus document of The Joint European Society of Cardiology/American College of Cardiology Committee for the redefinition of myocardial infarction.
All entries were validated by the Israel Association of Cardiovascular Research by reviewing charts and discharge documents. In-hospital and 30-day outcome data were ascertained by hospital chart review, telephone contact, and clinical follow-up data. Patient management was at the discretion of the attending physicians. Mortality data during hospitalization and at 30 days were determined for all patients from hospital charts and by matching identification numbers of patients with the Israeli National Population Register. Five-year mortality data were ascertained through the use of the Israeli National Population Registry. All parameters captured by the registry were defined by protocol. Data collection was approved at each hospital by the Institutional Ethics Review Committee.
Study Population and Outcome Measures
The current study population was comprised of all patients under the age of 55 years enrolled in 7 consecutive ACSIS surveys from 2000 through 2013. All patients had a discharge diagnosis of ST-elevation myocardial infarction, non-ST-elevation myocardial infarction, or unstable angina. There were no exclusion criteria from the study.
Outcome measures of the present study included in-hospital, 30-day, and 5-year all-cause mortality, as well as 30-day major adverse cardiac and cerebral events defined as recurrent myocardial infarction, stent thrombosis, ischemic stroke, urgent repeat revascularization, or death.
Statistical Analysis
A descriptive analysis was performed by presenting data as mean ± standard deviation, median, and interquartile range or frequency and percentage, when appropriate. All data were compared by sex, using chi-squared analysis for categorical variables, Student's t test, or Wilcoxon rank-sum for continuous variables, as appropriate. The cumulative probabilities of in-hospital mortality, 30-day major adverse cardiac and cerebral events, 30-day mortality, and 5-year mortality were graphically displayed according to the method of Kaplan and Meier, with comparison of cumulative events by the log-rank test. Multivariate analysis for all end points was carried out using Cox proportional hazards regression modeling. All analyses were performed by the Israeli Association for Cardiovascular Trials using SAS statistical software (version 9.3, SAS Institute, Cary, NC). A 2-sided P-value <.05 was used for declaring statistical significance.
Results
Study Population and Baseline Characteristics
The study population was comprised of 3949 young patients (<55 years old) enrolled in 7 consecutive surveys (ACSIS 2000 through 2013), of whom 407 (10.3%) were women and 3542 were men. Interestingly, we found a general trend of a decline in the total proportion of young (<55 years old) patients among the total registry population (P for trend .07), mainly driven by a decline in rates of young men (P for trend .008) presenting with acute coronary syndrome. As expected, the number of men hospitalized each year was more than twofold higher than the number of women (P <.0001).
Baseline characteristics are presented in Table 1. Women had higher rates of diabetes mellitus and hypertension, whereas more men had past history of smoking. Beyond these differences, both groups were well balanced. Predictably, a positive family history of ischemic heart disease was common in both sexes (37% and 41% for women and men, respectively), and the rate of active smoking was strikingly high in both sexes.
Comparisons of clinical presentation and hospital management are summarized in Table 2. Women were more commonly deemed to have atypical chest pain and tended to present with higher rates of acute heart failure as indicated by higher Killip class on admission and higher Global Registry of Acute Coronary Events (GRACE) score (>140). This was despite a lower proportion of ST-elevation acute coronary syndrome among women. Expectedly, women had higher average high-density lipoprotein levels compared with men, but the majority of patients in both groups were found to be below the normal threshold (45 mg/dL for women and 40 mg/dL for men).
Table 2Presentation and Hospitalization Characteristics According to Sex
Men n = 3542
Women n = 407
P Value
Presentation
Atypical angina, %
19
23
.05
STE on first ECG, %
56
47
<.001
Dyspnea, %
8
14
<.001
Killip class ≥II, %
6
11
<.001
GRACE score >140
11.8
18.8
.003
Heart rate, beats per minute, mean ± SD
80.4 ± 18.6
84.3 ± 20.2
<.001
Time intervals (all ACS)
Symptom onset to ED arrival, min, median (IQR)
149 (77-401)
172 (90-502)
.079
Symptom onset to first ECG, min, median (IQR)
140 (70-410)
180 (90-530)
.031
Time intervals (STEMI)
Symptom onset to ED arrival, min, median (IQR)
118 (118-240)
129 (70-302)
.076
Door to balloon time, min, median (IQR)
61 (34-96)
69 (40-100)
.796
Door to balloon time <90 min, %
72.8
77.1
.573
Ejection fraction, %, median (IQR)
50 (42-60)
50 (40-60)
.540
Laboratory findings during hospitalization
Hemoglobin gr/dL, mean ± SD
14.7 ± 5.7
13.2 ± 6.9
<.001
LDL, mg/dL, mean ± SD
43.2 ± 11.9
43.2 ± 11.9
.180
HDL, mg/dL, mean ± SD
37.4 ± 10.9
43.2 ± 11.8
<.001
Low HDL (<45), %
83.9
47.7
<.001
GFR, ml/min, mean ± SD
89 ± 23
84 ± 23
.003
GFR ≤60 (%)
7.0
15.8
<.001
Treatment during hospitalization
Coronary angiography
87
83
.024
Total PCI
71
61
<.001
PCI among patients undergoing coronary angiography
There were no differences between sexes in the pharmacologic management during hospitalization. However, women received less invasive therapy; fewer women underwent invasive coronary angiography as compared with men. This finding remained significant after adjustment for relevant confounders (odds ratio for women to undergo coronary angiography 0.68; 95% confidence interval, 0.48-0.97; Table 3). Subsequently, rates of percutaneous coronary intervention were also significantly lower in women, which may be partially explained by differences in the performance of coronary angiography. We observed a higher proportion of angiographically normal or nonsignificant coronary disease in women, while rates of multivessel disease were higher in men. Indeed, the likelihood of women undergoing percutaneous coronary intervention after adjustment for relevant clinical and angiographic confounders was similar to men (odds ratio 0.95; 95% confidence interval, 0.65-1.39; Table 3).
Table 3Predictors for Undergoing Coronary Angiography During Index Hospitalization
During the study period, rates of ST-elevation myocardial infarction decreased in both groups (P value for trend <.05). There was a trend toward lower rates of primary reperfusion in women presenting with ST-elevation acute coronary syndrome. There were no differences between sexes in patient-related delay or door-to-balloon time among patients presenting with ST-elevation acute coronary syndrome. Specifically, rates of door-to-balloon time <90 minutes were similar in both sexes. In this subset of patients, the left anterior descending artery was the most common infarct-related artery in both sexes, but the left main coronary artery was more frequently the culprit in women.
In-Hospital Complications and Outcome
A greater proportion of women had a higher Killip class (>1) on admission, and a higher proportion of women developed cardiogenic shock during the index hospitalization. Rates of other in-hospital complications were relatively low and similar in both sexes (Table 4).
Table 4Unadjusted Outcomes According to Sex
Male n = 3542
Female n = 407
Log-Rank P-Value
In-hospital mortality, %
1.0
2.7
.004
30-day outcomes, %
Mortality, %
1.4
3.1
.01
MACCE, %
2.3
5.5
.005
Recurrent MI, %
1.2
1.4
.650
Stroke, %
0.3
0.7
.119
1-year mortality, %
2.2
5.5
<.001
5-year mortality, %
6.6
13.7
<.001
In-hospital complications
Cardiogenic shock, %
1.5
3.2
.012
Major bleeding, %
0.5
1.2
.141
Acute renal failure, %
1.6
2.3
.322
High degree AV block, %
1.6
2.6
.184
AV = atrioventricular; MACCE = major adverse cardiac and cerebrovascular events; MI = myocardial infarction.
Over an average follow-up of 4.8 ± 0.86 years, 13.7% of the women and 6.6% of the man in our cohort died (P <.001, Table 4). Kaplan-Meier survival analysis showed significantly higher rates of in-hospital and 5-year all-cause mortality (Figure 1), and 30-day major adverse cardiac and cerebral events in women (data not shown). These findings persisted after adjustments in a series of multivariate analysis models (Table 5). Additional independent predictors of 5-year mortality were GRACE score >140, diabetes mellitus, and previous history of myocardial infarction (Table 6). Importantly, recruitment during the more recent ACSIS surveys (2008-2013) was independently associated with decreased mortality in a multivariate model, indicating an improvement in outcomes over the passing decade.
Figure 1Cumulative probability of 5-year all-cause mortality by sex.
Table 5Multivariate Analysis: Risk of Major Outcomes in Women vs Men
Hazard Ratio
95% CI
P Value
In-hospital mortality
4.01
1.15-14.03
.033
30-day MACCE
2.1
1.31-3.36
.002
30-day mortality
5.63
1.75-18.04
.004
1-year mortality
2.51
1.08-5.83
.032
5-year mortality
1.96
1.35-2.84
<.001
Adjusted for: age, history of prior myocardial infarction, GRACE score >140, diabetes mellitus, hypertension, year of survey, percutaneous coronary intervention during the index hospitalization and low high-density lipoprotein.
CI = confidence interval; GRACE = Global Registry of Acute Coronary Events; MACCE= major adverse cardiac and cerebrovascular events.
Prespecified subgroup analysis showed a strong interaction between women and smoking, indicating an increased risk of mortality in female smokers compared with male smokers (Figure 2). No additional significant interactions were found.
Figure 2Hazard ratios for 1-year all-cause mortality in women as compared with men in subgroups. CI = confidence interval; GRACE = Global Registry of Acute Coronary Events; PCI = percutaneous coronary intervention; PMI = prior myocardial infarction.
Unlike the pharmacologic treatment during the hospital stay, women were discharged with a much less intensive, less evidence-based treatment regimen (Table 2). The prescription rates were lower for all guideline-recommended secondary prevention medications, including aspirin, dual antiplatelet therapy, beta-blockers, angiotensin-converting enzyme (ACE) inhibitors, and statins. This disparity is further emphasized by the fact that women had a higher proportion of hypertension at baseline and were more commonly chronically treated with statins prior to admission.
Discussion
Our analysis of sex-related differences in outcomes of younger patients admitted with acute coronary syndrome is based on real-world, contemporary Israeli national surveys over a 13-year period, and shows several notable findings. First, in contrast to men, there is no decrease in the rates of young women presenting with acute coronary syndrome over the passing decade. Second, women delayed longer prior to seeking medical attention and had a higher-risk profile upon admission, as depicted by worse GRACE score and Killip class, despite a lower proportion of ST-elevation myocardial infarction. Next, we found disparities in the acute management of women with lower rates of coronary angiography and subsequent percutaneous coronary intervention during the index hospitalization. While medical treatment during hospitalization was similar, we found major differences in the intensity of the recommended pharmacologic treatment upon discharge. Most importantly, we have shown that younger women have significantly poorer short- and long-term outcome as compared with men, and higher rates of adverse events at 30 days. These differences remained highly significant also after adjustment for GRACE score and other covariants and were evident in all sub-groups analyzed. The additional risk was further accentuated in women who smoke.
Several previous studies have shown higher rates of in-hospital mortality among young woman with acute coronary syndrome.
based on 42,518 men and women under 65 years of age discharged with a diagnosis of acute myocardial infarction found higher rates of all-cause readmission within 30 days among women. Poorer long-term outcomes in young women have been previously shown by Vaccarino et al
however, both studies predate the routine use of primary percutaneous coronary intervention in ST-elevation myocardial infarction, the early invasive approach to non-ST-elevation acute coronary syndrome and other current management strategies. Our results support previous findings, but strikingly, show that in the modern era of advanced therapy of acute coronary syndrome, female sex in younger patients remains independently associated with worse long-term survival at 5 years, and higher rates of major adverse cardiac and cerebral events at 30 days. Furthermore, over 13 years, no improvement has been seen in the outcomes of women. A recent review of studies reporting on sex-related differences in outcomes of myocardial infarction also suggested that age may be an effect modifier, as studies examining stratified analyses by age tended to show higher mortality for younger women but lower mortality for older women compared with men of the same age. Standard age adjustment in the older studies may not be sensitive to increased risk of adverse outcomes in this subgroup of younger women, due to the higher mean age of presentation in women.
based on a large American registry of patients with acute myocardial infarction, has shown an opposite trend, with a decline in crude in-hospital mortality in women from 2001 to 2010. This discrepancy may result from differences in study population and inclusion criteria, specifically, the fact that their study did not cover the entire acute coronary syndrome spectrum.
The pathophysiology behind these findings of worse outcomes of acute coronary syndrome in young women is likely to be multifactorial and may include biological and environmental factors. Women in our study had a higher burden of diabetes mellitus, which is known to be strongly and independently associated with long-term mortality. However, there was no significant interaction between sex and diabetes, and the excess mortality persisted after adjustment for diabetes and other baseline differences. In concordance with other studies, we found major differences in the clinical presentation of women during the index hospitalization. They were more often described as having atypical chest pain, more often showed signs of acute heart failure, and generally had worse Killip class and GRACE score. Some of the excess mortality may result from the longer delays in reaching medical contact or from other inherent biological differences that lead to susceptibility to adverse events. Alternatively, as was suggested by Vaccarino et al,
it may be the result of selection bias, as women with milder cases of unstable angina and atypical presentation may be missed more often than men with similar low-risk profile. This would artificially increase the proportion of severe cases in women who are admitted and included in any analysis. Nevertheless, female sex in our study remained a significant independent predictor of mortality even after adjustment to GRACE score and Killip class. These findings suggest that women are at increased risk as compared with men, and their increased risk is not related to the conventional risk profile of acute coronary syndrome patients.
The deleterious effect of smoking has been consistently shown across a wide range of medical conditions, and it is considered a major risk factor for the development of ischemic heart disease and myocardial infarction.
studies found a particularly harmful effect on women, showing that the attributable dose-dependent risk of smoking is significantly higher among women. Our results support these findings and highlight the specific importance of education aimed at prevention of smoking and smoking cessation among women.
The acute treatment of women presenting with acute coronary syndrome has been extensively studied and was found to differ from men. Several studies have found a tendency toward less invasive management of women. While we found no difference in the pharmacologic treatment during hospitalization, women were less likely to undergo coronary angiography. Once angiography was performed, the likelihood of percutaneous coronary intervention was affected by the coronary anatomy and not by sex. In agreement with previous studies,
Characterization and outcomes of women and men with non-ST-segment elevation myocardial infarction and nonobstructive coronary artery disease: results from the Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes with Early Implementation of the ACC/AHA Guidelines (CRUSADE) quality improvement initiative.
we have found a significantly higher prevalence of nonobstructive coronary disease in women. This may reflect a greater significance of less common pathophysiological processes leading to acute coronary syndrome in young women. Several possible mechanisms have been implied,
part of which have been shown to occur more commonly in women, mainly plaque disruption with reperfusion, plaque erosion, coronary spasm, embolism, and highly vulnerable eccentric atherosclerotic plaques characterized by high lipid pool and thin fibrous cap. Those are not readily demonstrated by standard angiography but may only be diagnosed using intravascular imaging. Furthermore, Takotsubo syndrome, coronary embolism, myocarditis mimicking myocardial infarction, and coronary microvascular spasm may all partially explain these differences in angiographic findings.
Data about the prognostic implication of nonobstructive coronary artery disease in patients with non-ST-elevation acute coronary syndrome is conflicting.
Characterization and outcomes of women and men with non-ST-segment elevation myocardial infarction and nonobstructive coronary artery disease: results from the Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes with Early Implementation of the ACC/AHA Guidelines (CRUSADE) quality improvement initiative.
Unanswered questions for management of acute coronary syndrome: risk stratification of patients with minimal disease or normal findings on coronary angiography.
Prognostic implications of elevated troponin in patients with suspected acute coronary syndrome but no critical epicardial coronary disease: a TACTICS-TIMI-18 substudy.
Most studies suggest that the prognosis after myocardial infarction in the setting of nonobstructive epicardial coronary artery disease is better than that of obstructive disease, but not benign. However, a recent analysis based on the Acute Catheterization and Urgent Intervention Triage Strategy (ACUITY) trial of patients with non-ST-elevation acute coronary syndrome and elevated troponin levels showed that those with nonobstructive coronary artery disease have higher 1-year mortality rates as compared with those with significant obstruction, albeit for noncardiac reasons.
Prognosis of patients with non-ST-segment-elevation myocardial infarction and nonobstructive coronary artery disease: propensity-matched analysis from the acute catheterization and urgent intervention triage strategy trial.
Inversely, the prognosis of ST-elevation myocardial infarction patients in the presence of nonobstructive coronary artery disease appears to be better than that of patients with an obstructive lesion.
Long-term prognosis of patients presenting with ST-segment elevation myocardial infarction with no significant coronary artery disease (from the HORIZONS-AMI trial).
Another possible explanation is the disparity in long-term medical treatment. Our data show a significant underutilization of dual antiplatelet therapy, statins, and ACE inhibitors in women. Those results are in accordance with previous studies that found a consistently lower utilization rate of secondary prevention medications in women.
Gender disparities in the diagnosis and treatment of non-ST-segment elevation acute coronary syndromes: large-scale observations from the CRUSADE (Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes With Early Implementation of the American College of Cardiology/American Heart Association Guidelines) National Quality Improvement Initiative.
A study based on a large Canadian registry found that women had a lower likelihood of receiving ACE inhibitors and lipid-lowering agents even after adjustment for all relevant variables.
Similar results with lower rates of treatment with aspirin and statins were reported in a study based on the American College of Cardiology-National Cardiovascular Data Registry.
Gender differences among patients with acute coronary syndromes undergoing percutaneous coronary intervention in the American College of Cardiology-National Cardiovascular Data Registry (ACC-NCDR).
While underutilization of antiplatelet therapy may be theoretically explained by lower rates of percutaneous coronary intervention in women, this finding remains even in an analysis of a post-percutaneous coronary intervention population.
An alternative explanation may be the higher rates of nonobstructive coronary artery disease found in women. This notion is supported by a previous study based on the 2004-2010 ACSIS surveys that showed underutilization of evidence-based medications in patients with nonobstructive coronary artery disease.
Characteristics and management of patients with acute coronary syndrome and normal or non-significant coronary artery disease: results from Acute Coronary Syndrome Israeli Survey (ACSIS) 2004-2010.
Our study has several limitations: results are derived from the ACSIS registry, which is comprised of a population admitted to cardiology wards and intensive cardiac care units nationwide with the diagnosis of acute coronary syndrome. Less typical cases of chest pain, although ultimately diagnosed as acute coronary syndrome, may have been managed in the internal medicine wards and therefore are not represented in the current study. As noted earlier, this may result in a selection bias for higher-risk patients that may be more significant in women. Of note, the ACSIS registry has limited follow-up data beyond the index hospitalization with respect to long-term medical treatment, adherence to treatment, and additional interventions. Therefore, the long-term outcomes may be significantly influenced by these and other postdischarge intervening factors, as well as some other unidentifiable parameters not included in our analysis.
Conclusion
In this contemporary registry of young acute coronary syndrome patients, we found that in patients under 55 years of age, female sex is independently and significantly associated with increased hospital mortality, increased 30-day major adverse cardiac and cerebral events and mortality, and increased 5-year mortality. There were major differences in the baseline characteristics and clinical presentation of women as compared with men. We show a gap in the quality of treatment of women with less invasive management and lower intensity of secondary prevention medications. Further studies are needed to clarify the underlying mechanisms explaining this observation and to establish a better therapeutic strategy for younger women with acute coronary syndrome.
References
Rosengren A.
Wallentin L.
Simoons M.
et al.
Age, clinical presentation, and outcome of acute coronary syndromes in the Euroheart acute coronary syndrome survey.
Bridging the gender gap: Insights from a contemporary analysis of sex-related differences in the treatment and outcomes of patients with acute coronary syndromes.
Myocardial infarction redefined–a consensus document of The Joint European Society of Cardiology/American College of Cardiology Committee for the redefinition of myocardial infarction.
Characterization and outcomes of women and men with non-ST-segment elevation myocardial infarction and nonobstructive coronary artery disease: results from the Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes with Early Implementation of the ACC/AHA Guidelines (CRUSADE) quality improvement initiative.
Unanswered questions for management of acute coronary syndrome: risk stratification of patients with minimal disease or normal findings on coronary angiography.
Prognostic implications of elevated troponin in patients with suspected acute coronary syndrome but no critical epicardial coronary disease: a TACTICS-TIMI-18 substudy.
Prognosis of patients with non-ST-segment-elevation myocardial infarction and nonobstructive coronary artery disease: propensity-matched analysis from the acute catheterization and urgent intervention triage strategy trial.
Long-term prognosis of patients presenting with ST-segment elevation myocardial infarction with no significant coronary artery disease (from the HORIZONS-AMI trial).
Gender disparities in the diagnosis and treatment of non-ST-segment elevation acute coronary syndromes: large-scale observations from the CRUSADE (Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes With Early Implementation of the American College of Cardiology/American Heart Association Guidelines) National Quality Improvement Initiative.
Gender differences among patients with acute coronary syndromes undergoing percutaneous coronary intervention in the American College of Cardiology-National Cardiovascular Data Registry (ACC-NCDR).
Characteristics and management of patients with acute coronary syndrome and normal or non-significant coronary artery disease: results from Acute Coronary Syndrome Israeli Survey (ACSIS) 2004-2010.
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