Effect of risk factors on the mechanism of acute thrombosis and sudden coronary death in women

Impact of plaque rupture on infarct size in ST-segment elevation anterior acute myocardial infarction

OBJECTIVES

We sought to assess whether coronary plaque rupture at culprit lesions is associated with infarct size in patients with anterior acute myocardial infarction (AMI).

BACKGROUND

Some patients with AMI have large infarcts despite early reperfusion. Whether culprit plaque morphology impacts infarct size or not remains unknown.

METHODS

Patients who had a first anterior AMI with reperfusion within 6 hours after onset were enrolled and divided into 2 groups according to the presence or absence of plaque rupture at the culprit lesion as defined by preintervention intravascular ultrasound (IVUS): patients with rupture (n = 54) and without rupture (n = 37).

RESULTS

Patients with plaque rupture had a higher incidence of no-reflow phenomenon (15% vs. 3%; p = 0.08) and a lower myocardial blush grade (1.5 vs. 2.3; p < 0.05) after percutaneous coronary intervention. The IVUS analysis showed that patients with plaque rupture had a higher incidence of soft plaque and positive remodeling. Peak creatine kinase levels were higher (4,707 vs. 2,309 IU/l; p < 0.0001) and left ventricular ejection fraction in the chronic phase was lower (54% vs. 63%; p < 0.01) in patients with plaque rupture. A multivariate logistic regression analysis revealed that plaque rupture and the proximal lesion site correlated with a left ventricular ejection fraction of <50% in the chronic phase (odds ratios 6.5 and 17.5, respectively; p < 0.05).

CONCLUSIONS

Plaque rupture is associated with morphologic characteristics of vulnerable lesions, as well as with larger infarcts and a higher incidence of no-reflow phenomenon, suggesting that plaque embolism contributes to the progression of myocardial damage in patients with anterior AMI.

Myocardial infarction in the young: a sex-based comparison

A relative paucity of information concerns the natural history, clinical features and coronary anatomy in young patients with acute myocardial infarction. In particular, there is a dearth of data relating to sex differences in young patients. The objective was to evaluate whether or not there are correlations between the clinical characteristics and the extent and localization of coronary artery lesions in young men compared with young women. The study population consisted of 1646 young patients (87% men, 13% women; mean age 39+/-5 years) with a first acute myocardial infarction admitted to one of the 125 coronary care units of Italy in a period of 3 years. Clinical data were collected. All patients underwent coronary angiography during hospitalization. Smoking, hypercholesterolemia and obesity were significantly more prevalent in men than in women; physical inactivity was significantly more prevalent among women. Hemodynamically significant coronary stenosis occurred in 82% of patients and were more frequent in men than in women (P<0.05). Women more frequently had single-vessel disease and no coronary lesions at all (58 vs. 47% and 24 vs. 9% women vs. men respectively, both P<0.05). Men more frequently had multivessel disease (38 vs. 13%, P<0.05). Significant stenosis mainly affected the left anterior descending artery (52%) with no gender-related difference; men more likely had lesions of the left circumflex or right coronary artery (P<0.05). In conclusion, young patients with a first acute myocardial infarction risk factors profile and extent of coronary artery lesions were significantly different between sexes.

Interaction between cytokines and sCD40L in patients with stable and unstable coronary syndromes

BACKGROUND

Evidence suggests that soluble CD40-ligand (sCD40L) is elevated in coronary artery disease (CAD) and is released from activated platelets during the acute myocardial infarction (AMI). Although sCD40L is part of immune response, the mechanisms regulating its release in different disease states remain unknown.

MATERIALS AND METHODS

This study enrolled 596 subjects: 201 patients with stable CAD, 109 patients with AMI and 286 healthy controls. Circulating levels of sCD40L, interleukin-6 (IL-6), soluble vascular cell adhesion molecule-a (sVCAM-1) and soluble intercellular adhesion molecule-1 (sICAM-1) were determined by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Patients with AMI (n = 109) had higher levels of sCD40L and IL-6 compared to both CAD (n = 201) (P < 0.01) and controls (n = 286) (P < 0.01), while CAD also had higher levels of sCD40L and IL-6 compared to controls (P < 0.01). Similarly, sICAM-1 and sVCAM-1 levels were higher in CAD and AMI compared to controls (P < 0.05). IL-6 was the only parameter independently associated with sCD40L in healthy individuals [beta (SE):0.491(0.096), P = 0.0001]. However, in CAD or AMI, only diabetes mellitus [beta (SE): 2.689 (1.082), P = 0.044 and beta (SE): 10.406 (3.215), P = 0.002, respectively] and smoking [beta (SE): 3.470 (1.111), P = 0.002 and beta (SE): 9.694 (2.478), P = 0.0001, respectively] (but not IL-6), were independently associated with sCD40L levels.

CONCLUSIONS

Both CAD and AMI are accompanied by increased levels of sCD40L in parallel with an elevation of proinflammatory cytokine IL-6 and adhesion molecules sVCAM-1 and sICAM-1. Diabetes mellitus and smoking (but not IL-6 or adhesion molecules) were the only factors independently associated with sCD40L levels in CAD and AMI patients.

Increase of scavenger receptor A-positive monocytes in patients with acute coronary syndromes

To evaluate the utility of the scavenger receptor A (SRA) index (no. SRA(+) monocytes observed in 10 high-power fields of peripheral blood (PB) smear samples, normal upper limit <30) as the indication of disrupted, fissured, or eroded plaque, 225 patients with acute myocardial infarction (AMI), 79 with unstable angina (UA) and 91 with stable angina (SA) were examined. Thrombus was gathered from 95 of 205 sequential AMI patients (46.3%), and classified into platelets, mixed, and two kinds of residual mural thrombus (RMT). RMT was observed in 56 of 169 (33.1%) AMI patients with SRA index > or =30 at hospitalization. The SRA index of 82.4% of AMI, and 75.9% of UA, and 70.3% of SA patients was > or =30 at hospitalization. For 36 AMI patients who initially had an SRA index of <30 at hospitalization, it exceeded 30 within 2 days, and the SRA index rapidly increased in most AMI patients after hospitalization. SRA(+) monocytes were considered to differentiate from SRA(-) monocytes in PB. An abnormally high SRA index is considered to be a useful indication of disrupted or fissured or eroded plaque.

Intravascular ultrasonic study of gender differences in ruptured coronary plaque morphology and its associated clinical presentation

Coronary plaque rupture is a phenomenon underlying most acute coronary events. Although gender is an important determinant of the incidence and clinical course of coronary atherosclerosis, its relation to plaque rupture is unknown. Therefore, we assessed gender differences in native artery plaque rupture characteristics and their related clinical presentations. There were 468 intravascular ultrasound (IVUS) preintervention images of ruptured plaques retrospectively identified. There were 328 men (81.6%) with 387 plaque ruptures and 74 women (18.4%) with 81 plaque ruptures. Patient demographics, angiographic characteristics, and qualitative and quantitative IVUS analyses of ruptured plaques were assessed. On average women were older than men (67.6 +/- 11.8 vs 62.6 +/- 11.4 years, p = 0.001) and more often presented with an acute coronary syndrome (89.2% vs 72.9%, p = 0.003). Older women had smaller vessel areas at the rupture site (p = 0.001), minimum lumen site (p = 0.002), and reference segments (p = 0.002) and smaller lumen areas at the rupture site (p = 0.026) and reference segments (p = 0.03). Ruptured plaques in older women were more often associated with IVUS-evident thrombus (48.1% vs 34.6%, p = 0.022). Independent predictors of acute clinical presentation were female gender (p = 0.006), smoking (p = 0.013), and presence of thrombus (p = 0.049). Independent predictors of the presence of thrombus were female gender (p = 0.025), smaller lumen area (p = 0.023) and larger plaque area (p = 0.008) at the rupture site, longer plaque ruptures (p = 0.016), and smoking (p = 0.045). In conclusion, coronary plaque ruptures are more often associated with thrombus and acute presentations in women than in men.

Relationship between a systemic inflammatory marker, plaque inflammation, and plaque characteristics determined by intravascular optical coherence tomography

OBJECTIVE

The purpose of this study was to evaluate the relationships between the peripheral white blood cell (WBC) count, local plaque fibrous cap macrophage density, and the morphological features and presence of thin-cap fibroatheromas (TCFA) identified by optical coherence tomography (OCT).

METHODS AND RESULTS

OCT was performed in patients undergoing catheterization. Images were analyzed using validated criteria for plaque characteristics. Baseline WBC count correlated with macrophage density (r=0.483, P<0.001). Both parameters were associated with lipid-rich plaque and correlated inversely with plaque fibrous cap thickness (r=-0.547 for macrophage density and -0.423 for WBC count, P<0.015). Plaques classified as TCFA had a higher median macrophage density than non-TCFA plaques (7.4 versus 4.99, P<0.001). Patients with TCFA had a higher WBC count compared with those without TCFA (11.0 versus 7.9, P=0.007). Receiver operator curves for WBC count, macrophage density, and these combined parameters for prediction of TCFA showed the area under the curves were 0.88, 0.91, and 0.97 (P<0.001), respectively.

CONCLUSION

This study provides the first in vivo data linking the peripheral WBC count, plaque fibrous cap macrophage density, and the characteristics and presence of TCFA. Macrophage density correlated with the WBC count, and both parameters independently and particularly in combination predict the presence of TCFA.

Hemodynamic factors and atheromatic plaque rupture in the coronary arteries: from vulnerable plaque to vulnerable coronary segment

Coronary plaque disruption with superimposed thrombosis is the underlying pathology in the acute coronary syndromes and sudden death. Coronary plaques are constantly stressed by a variety of mechanical and hemodynamic forces that may precipitate or 'trigger' disruption of vulnerable or, at extreme conditions, even stable plaques. This paper reviews the exciting new evidence on the hemodynamic factors that may play a role in this process and provides the rationale for the introduction of the concept of the vulnerable coronary segment in the study of acute coronary syndromes.

Cardiovascular risk in women: the impact of hormone replacement therapy and prospects for new therapeutic approaches

Cardiovascular disease (CVD) is the main cause of death in women. Observational studies of hormone replacement therapy (HT) and data from women with premature ovarian failure have provided support for the principle that estrogen confers protection against the development of CVD in premenopausal women. However, randomised, controlled trials investigating HT in postmenopausal women have failed to demonstrate a benefit of HT in the primary or secondary prevention of CVD. Nevertheless, HT may be effective if targeted at younger perimenopausal women. Research aimed at investigation of the cellular mechanisms of estrogen may result in the discovery of new therapeutic targets that may be able to harness the potential beneficial effects of estrogens in the cardiovascular system. An improved understanding of the distinct processes in the clinical presentation and progress of CVD in women will help develop new targets and enhance the use of current established drugs.

Smoking is associated with urinary albumin excretion: an evaluation of premenopausal patients with type 2 diabetes mellitus

Cigarette smoking and an increase in urinary albumin excretion are associated with high mortality in patients with type 2 diabetes mellitus. We tested the hypothesis that the presence of a smoking habit correlates with increased urinary albumin excretion in premenopausal Japanese women with type 2 diabetes mellitus. The study consisted of 20 premenopausal Japanese patients with type 2 diabetes mellitus in the current-smokers group (age, 45 +/- 4 years, mean +/- SD). The control group consisted of 35 age-matched never-smoker patients (age, 45 +/- 5 years). Serum triglyceride levels were higher and high-density lipoprotein cholesterol levels were lower in the current-smokers group than in the never-smokers group (P < .05 and P < .01, respectively). Furthermore, fasting plasma insulin concentrations and the homeostasis model assessment index were higher in the current-smokers group than in the never-smokers group (P < .005 and P < .001, respectively). Urinary albumin excretion also was higher in the current-smokers group than in the never-smokers group (P < .0001). Multivariate logistic analysis revealed that urinary albumin excretion is independently associated with current smoking in Japanese premenopausal with type 2 diabetes mellitus (odds ratio, 1.79; 95% confidence interval, 1.08-3.87; P < .01). The results of this study show that current smoking is associated with an increased level of urinary albumin excretion, suggesting that smoking was a risk factor in the development of increased urinary albumin excretion in these patients.

What are the most useful and trustworthy noninvasive anatomic markers of existing vascular disease?

Cardiovascular disease is the leading cause of mortality and morbidity in developed countries. Evidence challenges the notion that the severity of lesions on angiography is a predictor of future cardiac events. With the recognition that subclinical coronary artery stenoses are responsible for myocardial infarcts and sudden death, it may be important to identify patients with plaque characteristics that may place them at increased risk. Intravascular ultrasound, though invasive, remains the current imaging gold standard. Computed tomography, cardiac magnetic resonance, and single-photon emission CT positron emission tomography are evolving and promising modalities. Functional studies reflecting plaque temperature and molecular imaging reflecting plaque constituents are being developed. We review the pathology of the vulnerable atherosclerotic plaque and recent innovations in imaging modalities to assess plaque complication risk.

Does diabetes mellitus explain the higher hospital mortality of women with acute myocardial infarction? Results from the Berlin Myocardial Infarction Registry

BACKGROUND

Women with acute myocardial infarction (AMI) exhibit greater hospital mortality than do men. In general, diabetes mellitus is one of the major factors influencing the outcome of patients with AMI. The aim of this study was to analyze the interaction between diabetes and gender, specifically with regard to the higher hospital mortality of female AMI patients aged < or = 75 years.

METHODS

We prospectively collected data from 3,715 patients aged < or = 75 (2,794 men, 921 women) with acute myocardial infarction who were treated in 25 hospitals in Berlin, Germany, from 1999 to 2002. In a multivariate analysis, we specifically studied the interaction between the factors diabetes mellitus and gender in their effects on hospital mortality.

RESULTS

After adjustment in multivariate analysis, the interaction between gender and diabetes was statistically significant, and the estimated odds ratios were as follows: female diabetic patients compared with male diabetic patients, odds ratio (OR) = 2.28 (95% confidence interval [CI] 1.42-3.68); female diabetic patients compared with male nondiabetic patients, OR = 2.90 (95% CI 1.90-4.42); and female diabetic patients compared with female nondiabetic patients, OR = 2.92 (95% CI 1.75-4.87). There was no statistically significant difference between the risk of dying for female nondiabetic patients or for male diabetic patients when compared with male nondiabetic patients.

CONCLUSIONS

In AMI patients aged < or = 75 years, female gender alone is not an independent predictor of hospital mortality. Detailed, multivariate analysis reveals that specifically diabetic women demonstrate higher hospital mortality than do men. Special attention should be provided to these female diabetic patients.

Retinal vascular calibre and the risk of coronary heart disease-related death

OBJECTIVE

To examine whether retinal vascular calibre independently predicts risk of coronary heart disease (CHD) -related death.

METHODS

In a population-based cohort study of 3654 Australians aged > or = 49 years, retinal arteriolar and venular calibres were measured from baseline retinal photographs and the arteriole to venule ratio (AVR) was calculated. CHD-related death was confirmed from the Australian National Death Index.

RESULTS

Over nine years, 78 women (4.1%) and 114 men (7.8%) had incident CHD-related deaths. In people aged 49-75 years, wider venules were associated with CHD death, with relative risk (RR) 1.8 (95% confidence interval (CI) 1.1 to 2.7) and RR 2.0 (95% CI 1.1 to 3.6) per standard deviation (SD) increase in venular calibre for men and women, respectively, after adjustment for traditional risk factors. Additionally, in women aged 49-75 years, smaller AVR and narrower arterioles were associated with CHD death (RR 1.5, 95% CI 1.1 to 2.2, and RR 1.9, 95% CI 1.0 to 3.5 per SD decrease in AVR and arteriolar calibre, respectively, after adjustment). These associations were not observed in people aged > 75 years.

CONCLUSIONS

These findings suggest that microvascular disease processes may have a role in CHD development in middle-aged people, particularly in women. Retinal photography may be useful in cardiovascular risk prediction.

Pathology of the Vulnerable Plaque

The majority of patients with acute coronary syndromes (ACS) present with unstable angina, acute myocardial infarction, and sudden coronary death. The most common cause of coronary thrombosis is plaque rupture followed by plaque erosion, whereas calcified nodule is infrequent. If advances in coronary disease are to occur, it is important to recognize the precursor lesion of ACS. Of the three types of coronary thrombosis, a precursor lesion for acute rupture has been postulated. The non-thrombosed lesion that most resembles the acute plaque rupture is the thin cap fibroatheroma (TCFA), which is characterized by a necrotic core with an overlying fibrous cap measuring <65 microm, containing rare smooth muscle cells but numerous macrophages. Thin cap fibroatheromas are most frequently observed in patients dying with acute myocardial infarction and least common in plaque erosion. They are most frequently observed in proximal coronary arteries, followed by mid and distal major coronary arteries. Vessels demonstrating TCFA do not usually show severe narrowing but show positive remodeling. In TCFAs the necrotic core length is approximately 2 to 17 mm (mean 8 mm) and the underlying cross-sectional area narrowing in over 75% of cases is <75% (diameter stenosis <50%). The area of the necrotic core in at least 75% of cases is < or =3 mm2. These lesions have lesser degree of calcification than plaque ruptures. Thin cap fibroatheromas are common in patients with high total cholesterol (TC) and high TC/high-density lipoprotein cholesterol ratio, in women >50 years, and in those patients with elevated high levels of high sensitivity C-reactive protein. It has only recently been recognized that their identification in living patients might help reduce the incidence of sudden coronary death.

[Prevention of coronary heart disease: smoking]

Smoking is the leading preventable cause of illness and premature death in Germany, claiming over 110,000 lives a year because it directly increases the risk of dying from heart disease, stroke, emphysema and a variety of cancers. The overwhelming majority of smokers begin tobacco use before they reach adulthood. Among those young people who smoke, the average age is now 13-14. In Germany, about 39% of male and 31% of female adults (age 18-60 years) continue to smoke, despite information about the unequivocally negative health consequences of smoking. The exact mechanisms of smoking-related vascular disease are not yet known. Smoking causes acute hemodynamic alterations such as increase in heart rate, systematic and coronary vascular resistance, myocardial contractility, and myocardial oxygen demand. These short-term effects could lower the ischemic threshold in smokers with coronary artery disease and contribute to the increased risk for acute cardiovascular events. Endothelial damage is thought to be an initiating event in atherosclerosis and early studies have demonstrated that long-term smoking has direct toxic effects with structural changes of human endothelial cells. Recent research has shown the importance of the functional role of the endothelium in regulating vascular tone, platelet-endothelial interactions, leukocyte adhesion and smooth muscle cell proliferation via synthesis and release of a variety of substances such as nitric oxide. There is strong evidence that smoking leads to endothelial dysfunction mainly by increased inactivation of nitric oxide by oxygen-derived free radicals. Smoking also increases oxidative modification of LDL and is associated with lower HDL plasma levels. Smoking induces a systemic inflammatory response with increased leukocyte count and elevation of the C-reactive protein level. Importantly, the prothrombotic effects of smoking have been repeatedly demonstrated to cause alterations in platelet function, imbalance of antithrombotic vs prothrombotic factors, and decrease of fibrinolytic activity. Given the enormous health hazard of tobacco use, complete abstinence from smoking should be achieved. Smoking cessation counselling should be given to healthy subjects and even more vigorously to patients with manifested disease. Every effort should be undertaken to prevent children and adolescents from starting to smoke. Brief tobacco dependence treatment is effective, and every smoker should be offered at least brief treatment at every office visit. More intensive treatment is more effective in producing long-term abstinence from tobacco. Nicotine replacement therapy (nicotine patches or gum), clinician-delivered social support, and skills training are the three most effective components of smoking cessation treatment. A framework for tobacco control measures is necessary to reduce tobacco consumption and exposure to tobacco smoke. Recommendations on specific tobacco control interventions are: 1. increase in tobacco taxes; 2. comprehensive tobacco advertising bans; 3. legislation prohibiting smoking in work and public places; 4. prohibiting the sales of tobacco products to persons under 18; 5. comprehensive disclosure of the physical, chemical and design characteristics of all tobacco products; 6. training of health professionals to promote smoking prevention and cessation interventions; and 7. development of a national network of smoking cessation treatment services.

Acute myocardial infarction: clinical characteristics and plaque morphology between expansive remodeling and constrictive remodeling by intravascular ultrasound

BACKGROUND

According to recent intravascular ultrasound (IVUS) studies, expansive remodeling (ER) at the culprit lesion has been observed in almost 50% of patients with acute coronary syndrome and constrictive remodeling (CR) in 30%. The purpose of this study is to investigate the difference between ER and CR at the culprit lesion in patients with acute myocardial infarction (AMI).

METHODS AND RESULTS

Preinterventional IVUS images of 73 patients with AMI were identified. The remodeling index (RI) was defined as the ratio of the external elastic membrane (EEM) areas at the culprit lesion to the EEM areas at the proximal reference site. Expansive remodeling was defined as an RI > 1.05; CR, as an RI < 0.95. In patients with AMI, 40 patients (55%) showed ER on IVUS, whereas CR was observed in 18 patients (25%). Patients with ER were significantly older than those with CR (P < .005). The frequency of the presence of calcifications was higher in patients with ER than in those with CR (P < .0005). In patients with AMI with ER, soft plaque with small calcium was the most frequent (58%). Multivariate analysis revealed that age and the presence of calcifications remained as independent predictors of ER.

CONCLUSIONS

These findings suggest that ER relates to old age and calcification, and CR may contribute to early plaque progression than ER in patients with AMI.

Nicotine induces tissue factor expression in cultured endothelial and smooth muscle cells

BACKGROUND AND OBJECTIVES

Cigarette smoking is associated with an increased risk to develop myocardial infarction and ischemic stroke. However, the mechanisms responsible for these effects are still poorly understood.

AIM

To investigate whether nicotine, the major component of cigarette smoking, and its main metabolite, cotinine, might induce a pro-thrombotic state via stimulation of tissue factor (TF) expression in two cell population widely represented in the arterial wall such as endothelial cells (ECs), and smooth muscle cells (SMCs).

METHODS AND RESULTS

Incubation of ECs and SMCs with nicotine and cotinine induced TF expression in both cell types in a dose-dependent fashion, exerting its effect at the transcriptional level, as demonstrated by semiquantitative and by real-time PCR. Nicotine- and cotinine-induced TF expression was mediated by the activation of the transcription factor, nuclear factor-kappa B (NF-kappaB), as demonstrated by electrophoretic mobility shift assay and by the suppression of TF expression by the NF-kappaB inhibitor, pyrrolidine dithio carbamate ammonium.

CONCLUSIONS

These data indicate that nicotine and cotinine exert direct effects on ECs and SMCs, shifting them toward a pro-thrombotic state via induction of TF expression. These effects on cells of the vessel wall might explain, at least in part, the deleterious cardiovascular consequences of cigarette smoking.

Prognostic value of coronary artery calcium screening in asymptomatic smokers and non-smokers

AIMS

To determine the extent and prognostic significance of coronary artery calcium in asymptomatic smokers and non-smokers. Population data are available on the prognostic impact of smoking on atherosclerotic imaging measurements of the carotid and peripheral arteries. Limited data are available on the impact of cigarette smoking on the prognostic value of coronary calcium.

METHODS AND RESULTS

A referred patient registry of 10,377 asymptomatic individuals (40% were current smokers) was followed for death from all-causes at 5 years. Univariable and multivariable Cox proportional hazard models were calculated to estimate time to all-cause mortality. Cumulative 5-year survival was 96.9 and 98.4% for smokers when compared with non-smokers (P < 0.0001). Using a stratified Cox proportional hazards survival analysis, survival for non-smokers ranged from 99.7 to 89.6% with calcium score of 0-10 and >1000 (P < 0.0001). In comparison, smokers had survival rates ranging from 99.5 to 81.4% for calcium score of 0-10 to >1000 (P < 0.0001). When further evaluating the effect of age on prognosis by coronary calcium, there was an additive relationship between age and calcium that was exacerbated with smoking, resulting in higher relative risk ratios for older smokers with coronary calcium (P < 0.0001). For smokers <50 years of age, a calcium score >1000 was associated with a relative risk ratio that was elevated 8.9-fold (P = 0.029). Thus, resulting in an expected reduction in life expectancy of 4.8 years for smokers <50 years of age with a calcium score >400 (P < 0.0001).

CONCLUSION

The prognostic value of coronary artery calcium scoring was accurate in identifying a high-risk cohort of asymptomatic smokers and non-smokers. Young smokers with high-risk calcium scores have a four- to nine-fold increased risk of dying when compared with similarly aged non-smokers. When prospectively applied, evidence of a high-risk calcium score may be useful in educating patients as to their expected risk of dying over the next 5 years.

Coronary Artery Calcification Revisited

Calcification is a common finding in human coronary arteries. However, there is conflicting evidence for a link between calcification and plaque instability. Current intravascular ultrasound (IVUS) technology allows a definitive detection of the calcification and measurement of the vessel wall. Using preinterventional IVUS images, we clarified that in patients with acute myocardial infarction, small "spotty" calcifications prevailed, associated with a fibrofatty plaque and positive remodeling. Conversely, in patients with stable angina pectoris, extensive calcification was frequent. IVUS allows the detection of vulnerable plaques in coronary arteries, by identifying not only a large lipid core and positive remodeling, but also a spotty pattern of calcification.

Co-localization of von Willebrand factor with platelet thrombi, tissue factor and platelets with fibrin, and consistent presence of inflammatory cells in coronary thrombi obtained by an aspiration device from patients with acute myocardial infarction

BACKGROUND

Detailed histochemical analysis of coronary thrombi obtained freshly from acute phase of myocardial infarction patients may provide information necessary to understand the mechanism of coronary occlusive thrombus formation.

METHODS AND RESULTS

Coronary thrombi causing myocardial infarction were obtained from 10 consecutive patients of myocardial infarction in the acute phase, using a newly developed aspiration catheter. All the fixed specimens of coronary thrombi, by hematoxylin and eosin staining, were found to contain three major constituents, namely, platelets, densely packed fibrin and inflammatory cells, including polymorphonuclear and mononuclear cells, although their distribution in each specimen is totally heterogeneous. Immunohistochemical staining revealed the prominent presence of von Willebrand factor (VWF) at the sites of platelet accumulation, presence of tissue factor and platelets at the sites of deposition of fibrin fibrils. It also revealed the presence of CD16-, CD45- and CD34-positive cells, yet the functional roles of these cells have still to be elucidated. There are weak positive correlation between the number of inflammatory cells involved in the unit area of coronary thrombi specimen and the time of collection of the specimens after the onset of chest pain.

CONCLUSIONS

In spite of various limitations, our results contain information suggesting the possible role of VWF in platelet-thrombus formation, possible important role played by tissue factor and activated platelets in the formation of fibrin fibrils, and the positive relationship between inflammatory cells migration and the formation of occlusive thrombi in human coronary arteries.

Perspectives on Dyslipidemia and Coronary Heart Disease in Women

Coronary heart disease (CHD) remains the leading cause of death among American women. Numerous differences exist between younger and older women and between women and men with respect to the pathology of CHD and its incidence and prevalence over the life cycle. Differences in lipoprotein levels and lipid fractions play an important role in CHD risk. Hormonal influences on lipoprotein levels in women are complex, change throughout the life span, and are influenced by the administration of oral contraceptives and hormone replacement therapy. Women with obesity, metabolic syndrome, or diabetes have lipid profiles that adversely affect CHD risk. To date, no randomized trials testing the impact of lifestyle changes on lipoprotein levels and subsequent CHD events in non-institutionalized women have been performed, and women have not been well represented in clinical end point trials of pharmacologic lipid-lowering therapy. Available evidence suggests that lipid-lowering therapy with statins does provide benefit in reducing the risk of coronary events in women; however, women remain undertreated, and more data are needed to determine optimal cardiovascular prevention and treatment in this population.

Influence of gender on treatment and short-term mortality of patients with acute myocardial infarction in Berlin

AIMS

Previous studies have shown higher hospital mortality rates in women, especially younger women, than in men. In light of the fact that myocardial infarction therapy is rapidly developing, and since gender-specific aspects have been discussed in detail during recent years, it was our goal to re-evaluate factors influencing hospital mortality rate, especially those involving gender-specific differences, in the city of Berlin, Germany.

METHODS

We prospectively collected data from 5133 patients (3330 men and 1803 women) with acute myocardial infarction who were treated in 25 hospitals in Berlin during the years 1999 to 2002.

RESULTS

During hospitalization the overall mortality rate was 18.6% among women and 8.4% among men. Women were older (mean age for men 62 years; women 73 years) and less likely to be married (men 74.6%; women 36.9%) than men. Women generally took longer to arrive at the hospital after infarction than did men (median time: men 2.0 h; women 2.6 h). Women furthermore demonstrated a higher proportion of diabetes (men 22.8%; women 36.5%) and hypertension (men 58.0%; women 69.3%). Reperfusion therapy (men 68.8%; women 49.7%) and administration of beta-blockers (men 76.0%; women 66.0%) took place less often for women than for men. A multivariate analysis revealed the following factors to be independent predictors of hospital mortality: age, gender, diabetes mellitus, hypercholesterolemia, pre-existing heart failure, pre-hospital cardiopulmonary resuscitation, cardiogenic shock and pulmonary congestion on admission, admission to a hospital with >600 beds, ST-elevation in the initial ECG, reperfusion therapy, as well as beta-blocker and ACE inhibitor treatment within 48 h of hospitalization.

CONCLUSION

Even after adjustment in multivariate analysis, women with acute myocardial infarction still demonstrate a higher risk for in-hospital death than men.

Thrombus of the ascending aorta

We present two cases of a thrombus in the ascending aorta causing an acute myocardial infarction (AMI) and review the 10 other cases previously reported in the literature. This life-threatening condition appears to be more common in female smokers in their fifth decade. Suspicion should be raised in individuals at low risk for atherosclerotic disease with coronary angiographic findings not in keeping with the clinical presentation. The diagnosis may be obtained by transesophageal echocardiography, and we generally recommend surgical thrombectomy.

Smoking is associated with advanced coronary atherosclerosis in youth

Smoking is linked to atherosclerosis and coronary heart disease (CHD) in older adults. However, evidence that smoking affects coronary atherosclerosis in young people is incomplete. The Pathobiological Determinants of Atherosclerosis in Youth (PDAY) Study collected arteries, blood, and other tissues from persons 15 to 34 years of age dying of external causes and autopsied in forensic laboratories. Lesions in the proximal left anterior descending coronary arteries (LAD) from 1127 subjects were graded microscopically according to the American Heart Association criteria. Among individuals with advanced lesions (Grade 4 or 5), smokers had a greater prevalence of Grade 5 lesions than non-smokers (odds ratio 9.61, 95% confidence interval 2.34-39.57), a difference suggesting that smoking accelerates the transition from Grade 4 to Grade 5 lesions. This association occurred among both men and women, and among persons with and without other CHD risk factors. The difference in qualities of advanced lesions suggests that smoking possibly accelerates the transition from Grade 4 to Grade 5 lesions by promoting thrombosis and accretion on the intimal surface of the plaque.

Predictors of type and site of first acute myocardial infarction in men and women

BACKGROUND

The importance of pathophysiological mechanisms involved in onset of acute myocardial infarction (AMI) differs with age, gender, and risk profiles. Diversity in the triggering of cardiovascular events has been observed, particularly between men and women. Therefore, we investigated the relationship between age, gender, and risk factors and location of AMI and the presence of Q waves in ECG.

PATIENTS AND METHODS

Data was obtained from a chart review of 2958 patients with first AMI: 770 (26%) patients with non-Q-wave AMI and 2188 (74%) patients with Q-wave AMI. Four clinical groups were formed by predetermined criteria (anterior Q-wave, anterior non-Q-wave, inferior Q-wave, inferior non-Q-wave). A logistic regression was performed to assess independent predictors of AMI type and site.

RESULTS

Key findings were: 1) inferior non-Q-wave AMI was more frequent in young women (P<0.001); 2) inferior Q-wave AMI was more common in young men (P<0.001); 3) anterior non-Q-wave AMI was more common in older men (P<0.001). Multivariate analysis revealed that independent predictors of anterior non-Q-wave AMI were age over 65 (P=0.002), male gender (P=0.04) and hypercholesterolemia (P=0.0003), and that predictors of inferior Q-wave AMI were male gender (P<0.0001), smoking (P=0.04) and diabetes (P=0.049). In the gender-subgroup analyses, age <45 years (P=0.04), hypecholesterolemia (P=0.02) and smoking (P=0.01) were independent predictors of inferior Q-wave AMI whereas age >65 years (P<0.0001) and smoking (P=0.0003) were predictors of anterior non-Q-wave AMI in men. In women, age <45 years (P<0.0001) and smoking (P=0.02) were independent predictors of non-Q-wave AMI and hypercholesterolemia (P=0.02) was a predictor of inferior Q-wave AMI.

CONCLUSION

The link between particular types and the site of AMI and age, gender and risk factors suggest that the importance of pathophysiological mechanisms for onset of AMI differs according to sex and age subgroup.

Plaque erosion in the culprit lesion is prone to develop a smaller myocardial infarction size compared with plaque rupture

BACKGROUND

Acute myocardial infarction (MI) stems from a disruption of the plaque in the coronary artery. Based on postmortem examinations, such plaque disruption has been classified as either a rupture or an erosion. Unfortunately, it has been difficult to clinically identify plaque ruptures and plaque erosions during the development of acute MI. To elucidate the relationships between clinical features and the morphological characteristics of the infarct-related lesions, we observed the culprit lesions in patients with acute MI by coronary angioscopy and intravascular ultrasound.

METHODS

We examined culprit lesions in 107 patients with acute MI using coronary angioscopy and intravascular ultrasound immediately before performing percutaneous coronary intervention. The lesions were then classified as plaque ruptures or nonruptured erosions, and their clinical features were compared.

RESULTS

Among the lesions studied, 44 were classified as plaque ruptures, 28 were classified as plaque erosions, and 35 were unclassified. Patients with nonruptured eroded plaques had more preinfarction angina before the onset of MI than those with ruptured plaques (53.6% vs 22.7%, P = .0074). They also had less ST-segment elevation MI (71.4% vs 93.2%, P = .0185), lower peak creatine kinase levels (2029 +/- 1517 vs 4033 +/- 2699 IU/L, P = .0009), less distal embolization after percutaneous coronary intervention (3.6% vs 36.4%, P = .0014), and less Q-wave MI 1 month after onset (40.7% vs 88.4%, P < .0001).

CONCLUSION

Patients with eroded plaque lesions have smaller infarctions than those with ruptured plaque lesions, suggesting that an eroded plaque is less potently thrombogenic than a ruptured plaque.

Women and tobacco dependence

Millions of American girls and women have been drawn to smoking by an industry that has been clearly and systematically targeting women of all ages and life circumstances. Tobacco marketing strategies skillfully link cigarette use to typical female values. Biologically speaking, women are especially vulnerable to the legion of health problems of tobacco use. Smoking is a critical hazard for women in their reproductive years, particularly when they are pregnant.

Increased cardiac mortality in women compared with men in patients with acute myocardial infarction

OBJECTIVE

It has been reported that women with acute myocardial infarction (AMI) have a higher short-term mortality rate than men, but the reason is not known. The profile in relation to age, gender and risk factors was evaluated to compare AMI and unstable angina pectoris (UAP).

METHODS

Findings from 984 patients including 580 patients with AMI (129 women, 451 men) and 404 patients with UAP (131 women, 273 men) were analyzed by the South Osaka Acute Coronary Syndrome Study Group (SACS). The primary endpoint of the study was in-hospital death. The primary endpoints of interest (cardiac death) were fatal recurrent myocardial infarction, death from congestive heart failure, and sudden death.

RESULTS

Cardiac death during hospitalization within 30 days in AMI was higher in women than in men (12.4% vs 6.7%, p < 0.05). On the other hand, in UAP there was no significant difference between women and men (1.5% vs 0.7%, NS). The incidence of cardiac death in AMI was significantly higher for patients 75 years old and older (19.0%) than for patients less than 55 years old (4.2%), 55-64 years old (3.5%) and 65-74 years old (4.7%) (p < 0.001, respectively).

CONCLUSIONS

Cardiac death was higher for women compared with men in patients with AMI. The worse prognosis for the AMI women patients was likely to be derived from less performance of percutaneous coronary intervention, and a high incidence of severe myocardial infarction. Further research should be focused on the analysis of various clinical backgrounds.

Gender-based differences in the prognostic value of coronary calcification

PURPOSE

To investigate the use of electron beam tomography (EBT) screening to predict all-cause mortality in a large cohort of asymptomatic women and men.

METHODS AND RESULTS

We obtained mortality information from the National Death Index in 10377 asymptomatic individuals (40% women) referred by primary care physicians for coronary calcification screening. The average follow-up period was 5 +/- 3.5 years. Univariable and multivariable Cox proportional hazard models were developed to predict all-cause mortality. Women had a lower prevalence of coronary calcification and smaller calcification scores than men (p < 0.0001). Death rates were higher among older, diabetic, hypertensive, and currently smoking individuals both in women and in men. In unadjusted (chi-square = 82, p < 0.0001) as well as risk-adjusted (chi-square = 7, p = 0.007) Cox survival models, women had a greater probability of death than men in each strata of calcification. Relative risk (RR) ratios were increased 3.0-fold, 5.5-fold, and 5.5-fold, respectively, for women compared with men with coronary calcification scores of 101-399, 400-1000, and >1000 (p < 0.0001). Using receiver operating characteristics (ROC) curve analyses to assess coronary calcification added incremental prognostic value to Framingham risk scores (p < 0.0001).

CONCLUSIONS

In this cohort of asymptomatic women, coronary calcification screening provided incremental prognostic information after adjustment for traditional risk factors. EBT may be a useful tool for risk stratification in women, where the early diagnosis of coronary heart disease (CHD) remains a strong challenge.

Sudden cardiac death in patients with diabetes

Sudden cardiac death (SCD) affects over 450,000 people in the United States annually. The mechanisms involved are poorly understood. The predictors currently known include traditional coronary heart disease risk factors, electrocardiographic abnormalities, cardiac autonomic neuropathy, left ventricular hypertrophy, cardiomyopathy, and conduction abnormalities. Diabetes mellitus and impaired glucose tolerance are of special importance due to their increased prevalence reaching epidemic proportions and the elevated risk of SCD in people with these disorders. This article reviews the current predictors of SCD with a focus on people with diabetes, hoping to offer physicians and researchers a better understanding of and a solid ground for further needed research on this important cause of premature death.

The pathophysiology of cigarette smoking and cardiovascular disease: an update

Cigarette smoking (CS) continues to be a major health hazard, and it contributes significantly to cardiovascular morbidity and mortality. Cigarette smoking impacts all phases of atherosclerosis from endothelial dysfunction to acute clinical events, the latter being largely thrombotic. Both active and passive (environmental) cigarette smoke exposure predispose to cardiovascular events. Whether there is a distinct direct dose-dependent correlation between cigarette smoke exposure and risk is debatable, as some recent experimental clinical studies have shown a non-linear relation to cigarette smoke exposure. The exact toxic components of cigarette smoke and the mechanisms involved in CS-related cardiovascular dysfunction are largely unknown, but CS increases inflammation, thrombosis, and oxidation of low-density lipoprotein cholesterol. Recent experimental and clinical data support the hypothesis that cigarette smoke exposure increases oxidative stress as a potential mechanism for initiating cardiovascular dysfunction.

Coronary heart disease: the female heart is vulnerable

During the past decade, an overall theme has emerged, validating the exploration of gender-based differences in coronary heart disease (CHD) as a basis for clinical strategies to improve outcomes for women. Underrepresentation of women in most of CHD and lack of gender-specific reporting in many clinical trials continue to limit the available knowledge and evidence-based medicine needed to devise optimal managements for women with CHD. Control of conventional coronary risk factors provides comparable cardioprotection for men and women. Current evidence fails to show cardiac protection from menopausal hormone therapy. Clinical presentations of coronary heart disease (CHD) and management strategies differ between the sexes. Underutilization of proven beneficial therapies is a contributor to less-favorable outcomes in women. The contemporary increased application of appropriate diagnostic, therapeutic, and interventional managements has favorably altered the prognosis for women, particularly when the data are adjusted for baseline characteristics. Better education of women during office visits, earlier and more aggressive control of coronary risk factors, and a greater index of suspicion regarding chest pain and its appropriate evaluation may help to reverse the trend of late referral and late intervention. Research indicates that behavioral changes on the part of women and reshaping of practice patterns by their health care providers may dramatically reduce the number of women disabled and killed by CHD each year.

Role of coronary calcium screening in preventive cardiology

Over 7 million people in this country have coronary artery disease, and more than 500,000 die from its complications annually. Over 1 million Americans have an acute myocardial infarction each year, and in the majority of cases the event announcing the presence of coronary atherosclerosis is either sudden death or a disabling myocardial infarction. Therefore, the most desirable approach to such an epidemic is prevention rather than delayed treatment. Yet, statistics from primary care and subspecialty practices indicate that the preventive attitude of the majority of physicians is not sufficiently developed and remains limited in most training programs. Though traditional risk factors are very helpful in predicting the development of cardiovascular disease, many individuals suffer events in the absence of established risk factors for atherosclerosis. To meet the challenge of coronary artery disease, several tools have been developed to identify atherosclerotic disease in its preclinical stages in the hope of modifying its natural history. This review deals with the utilization of electron beam tomography for detection of coronary artery calcification as an additional tool available for use by preventive cardiologists and internists.

Pathology of the thin-cap fibroatheroma: a type of vulnerable plaque

Thin cap atheroma is the precursor of plaque rupture, which accounts for a majority of coronary thrombi. The morphologic features of thin cap atheromas that predict rupture are unknown, but we know from studies of ruptured plaques that large necrotic cores, fibrous cap < 65 microns and numerous macrophages within the cap likely indicate instability. There is some evidence that a speckled pattern of calcification is associated with vulnerability to rupture. There are usually multiple thin cap atheroma in the hearts of patients dying with acute plaque rupture, as well as multiple fibroatheromas with intraplaque hemorrhage. Targeted therapy for the purpose of stabilizing coronary lesions that are prone to rupture is a major future goal of the interventionist.

Vulnerable plaque: the pathology of unstable coronary lesions

Vulnerable plaques have been defined as precursors to lesions that rupture. However, coronary thrombosis may occur from other lesions like plaque erosion and calcified nodules, although to a lesser frequency than rupture. Therefore, the definition of vulnerable plaque should be all-inclusive. Using descriptive terminology, the authors define the precursor lesion of plaque rupture as "thin-cap fibroatheroma" (TCFA). Morphologically, TCFAs have a necrotic core with an overlying thin fibrous cap (< 65 mm) consisting of collagen type I, which is infiltrated by macrophages. These lesions are most frequent in the coronary tree of patients dying with acute myocardial infarction and least common in those with plaque erosion. TCFAs are more common in patients with high serum total cholesterol (TC) and a high TC to high density cholesterol ratio, in women > 50 years, and in those patients with elevated levels of high sensitivity C-reactive protein. TCFAs are mostly found in the proximal left anterior descending coronary arteries and less commonly in the proximal right or the proximal left circumflex coronary arteries. In TCFAs, necrotic core length is approximately 2-17 mm (mean 8 mm) and the underlying cross-sectional luminal narrowing in over 75% of cases is < 75% (< 50% diameter stenosis). The area of the necrotic core in at least 75% of cases is < or = 3 mm2. Clinical studies of TCFAs are limited as angiography and intravascular ultrasound (IVUS) catheters cannot precisely identify these lesions. Newer catheters and other techniques are at various stages of development and will play a significant role in the understanding of plaque progression and the development of symptomatic coronary artery disease.

Pathology of the unstable plaque

The term "vulnerable" in the context of human coronary plaques was originally intended to provide a morphological description consistent with lesions prone to rupture. Coronary thrombosis is now recognized as a diverse process arising from plaque rupture, erosion, or calcified nodules. These findings have prompted the search for more definitive terminology to describe the precursor lesion of rupture, now referred to as "thin-cap fibroatheromas." This review provides a focused discussion of the thin-cap fibroatheroma as a specific cause of acute coronary syndromes. The pathology of the unstable plaque is presented in reference to unstable angina, acute myocardial infarction, and sudden coronary death. The influence of risk factors for coronary artery disease on culprit lesion morphology is also discussed. Finally, the value of coronary calcification, as a predictor of unstable plaques in the clinical setting, is explored.

Clustering of traditional risk factors and precocity of coronary disease in women

BACKGROUND

Women usually develop coronary artery disease (CAD) 10 years later than men do. CAD in women is associated with menopausal status and the number and intensity of risk factors. But, when the age gap between men and women narrows, less is known about the influence of risk factors on CAD.

METHODS

We assessed the prevalence of traditional risk factors in 850 men and 468 women with stable CAD who had mean age, 58.3+/-8.6 and 58.8+/-10.3 years (P=NS), respectively.

RESULTS

Univariate analysis of risk factors showed that body mass index (BMI), hypertension (all three stages), diabetes, triglycerides (> or =2.8 mmol/l), cholesterol (> or =6.2 mmol/l) and family history were more prevalent in women. Smoking and previous myocardial infarction (MI) were more prevalent in men. Multivariable analysis disclosed hypertension, diabetes, dyslipidemia and family history as independent risk factors for women with stable CAD and smoking and previous MI as independent risk factors for men.

CONCLUSION

Clustering of traditional risk factors may explain the precocity of CAD in women who are near in age to men.

Differences in thrombolytic treatment and in-hospital mortality between women and men after acute myocardial infarction

There is evidence for gender differences in the treatment and outcome of acute myocardial infarction (AMI). However, little data exist about these differences in patients from the Arab Middle East. Therefore, we studied the influence of patient gender on the presentation, the use of thrombolytic therapy, and in-hospital mortality after AMI in Kuwaiti nationals. This is a retrospective study of all consecutive Kuwaiti patients admitted to the coronary care unit of a university hospital with the diagnosis of AMI between June 1994 and May 1997. A total of 89 women and 267 men were included. Women were older than men and had significantly higher rates of diabetes (72% vs 46%), hypertension (58% vs 33%) and hypercholesterolemia (80% vs 53%). Women were less likely to receive thrombolytic therapy (40% vs 62%, p=0.001). Fewer women were eligible for thrombolytic therapy (50% vs 66%, p<0.05). Of those who were eligible for thrombolysis there was no sex difference in receiving such treatment. The in-hospital mortality among women younger than 70 years was 2.5 times higher than among men in the same age group, while there was no difference in mortality between women and men aged 70 years and older. We conclude that women and men with AMI have different clinical characteristics and outcomes following AMI. There was no gender bias for the use of thrombolytic therapy. The higher in-hospital mortality in younger women, i.e. less than 70 years, compared to younger men, indicates that younger women with AMI should be considered as a high-risk group.