Predictive value of hemostatic factors for sudden death in patients with stable angina pectoris

In-hospital and long-term prognostic value of fibrinogen, CRP, and IL-6 levels in patients with acute myocardial infarction treated with thrombolysis

Plasma fibrinogen, C-reactive protein (CRP), and interleukin-6 (IL-6) levels in patients with acute myocardial infarction (AMI) receiving thrombolysis have been related to prognosis. The aim of this study was to investigate the time course of plasma fibrinogen, CRP, and IL-6 levels during the in-hospital phase in patients with AMI receiving thrombolysis, and their relationship to in-hospital and prognosis after 12-months follow-up. In 40 patients presenting with AMI within 6 hours of symptom onset and treated with thrombolysis, plasma fibrinogen, CRP, and IL-6 levels were measured on admission and after 6, 12, 24, 48, and 72 hours; 7 days; and 6 months. Patients with other diseases that can alter fibrinogen, CRP, or IL-6 levels were excluded. Patients had a clinical follow-up at 6 and 12 months, and the following cardiac events were recorded: cardiac death, recurrent angina, recurrent AMI, and heart failure. Plasma fibrinogen concentrations decreased significantly (p <0.01 vs admission levels) at 12 hours (425 +/-94 vs 322 +/-132 mg/dL), started to increase at 24 hours, reached peak value at 72 hours (602 +/-209 mg/dL), remained elevated at 7 days, and were back to admission levels at 6 months (375 +/-79 mg/dL). CRP levels increased significantly at 12 hours (0.73 +/-0.43 vs 0.23 +/-0.11 mg/dL, p <0.01), reached peak value at 72 hours (7.66 +/-3.28 mg/dL), decreased significantly on day 7 (2.32 +/-1.17 mg/dL), and at 6 months were within normal limits (0.49 +/-0.29 mg/dL). IL-6 levels increased significantly at 6 hours (14.03 +/-8.13 vs 6.37 +/-3.88 pg/mL, p <0.05), reached peak value at 24 hours (59.49 +/-23.57 pg/mL), started to decrease at 48 hours, and at 6 months were within normal limits (2.25 +/-1.24 pg/mL). During the in-hospital phase 33 patients had an uneventful course and 7 patients had complications (3 post-AMI angina; 4 heart failure). During the 12-month follow-up period 28 patients had an uneventful course, and 12 patients had complications (1 cardiac death, 5 recurrent angina, 2 recurrent AMI, and 4 heart failure). Regarding the in-hospital prognosis, fibrinogen, CRP, and IL-6 levels were significantly higher (p <0.05) in patients with complications from 48 to 72 hours, from 12 hours until day 7, and from 6 hours until day 7, respectively. During the 12-month follow-up period fibrinogen, CRP, and IL-6 levels were significantly higher in patients with complications (at 48, 24, and 24 hours, respectively) only in the subgroup of patients who had complications within the first 6 months following AMI. Multivariate analysis showed that CRP at 48 hours was the most important factor related to in-hospital prognosis (p = 0.02), and ejection fraction followed by CRP at 24 hours (p = 0.02) to 6-month prognosis (p = 0.018). Fibrinogen, CRP, and IL-6 levels alter in patients with AMI receiving thrombolysis, and are related both to in-hospital and to 6-month follow-up prognosis.

Short- and long-term risk factors for sudden death in patients with stable angina

Sudden death is most common and often the first manifestation of coronary heart disease although its risk is difficult to predict. It has been studied mainly in patients with severe ventricular arrhythmia or recent myocardial infarction, but little is known about the different risk factors for short- and long-term risk of sudden death in patients with stable angina. To assess risk factors for sudden death in patients with stable angina and angiographically proven coronary artery disease, 319 consecutive patients were recruited prospectively and followed-up. Patients with clinical heart failure or recent myocardial infarction were excluded. Clinical, angiographic and biological variables were recorded. The association between each variable and the risk of sudden death was assessed in univariate and logistic multivariate analysis. There were 25 sudden deaths during the follow-up period (97+/-29 months). The univariate predictors in the short-term (2 years) were: peripheral arterial disease, left ventricular hypertrophy, low density lipoprotein cholesterol and ejection fraction. The independent predictors were: peripheral arterial disease (relative risk: 6.3), ejection fraction (relative risk 1.05) and low density lipoprotein (relative risk: 1.8). In the long-term (8-10 years), body mass index, coronary score, ejection fraction and fibrinogen were univariate predictors. Only body mass index (relative risk: 1. 2), ejection fraction (relative risk: 1.06) and fibrinogen (relative risk: 2) remained independent predictors. The risk factors for sudden death in stable angina were time-dependent, peripheral arterial disease appeared as the best predictor with LDL for short time, and body mass index (obesity: index >27) and fibrinogen for long time. Ejection fraction was the only time-independent predictor.

Occlusive vascular diseases in oral contraceptive users. Epidemiology, pathology and mechanisms

Despite being an unprecedented departure from normal physiology, the combined oral contraceptive is not only highly effective, but it also has a remarkably good safety record. Concerns over safety persist, though, particularly with regard to venous thromboembolism (VTE), stroke and myocardial infarction (MI). Epidemiological studies consistently show an increase in risk of VTE, but the results are more contentious with regard to arterial diseases. Despite 40 years of research, the mechanisms behind these adverse effects are not understood. In this review, we integrate information from published studies of the epidemiology and pathology of the occlusive vascular diseases and their risk factors to identify likely explanations for pathogenesis in oral contraceptive users. Oral contraceptives induce both prothrombotic and fibrinolytic changes in haemostatic factors and an imbalance in haemostasis is likely to be important in oral contraceptive-induced VTE. The complexity of the changes involved and the difficulty of ascribing clinical significance has meant that uncertainty persists. A seriously under-researched area concerns vascular changes in oral contraceptive users. Histologically, endothelial and intimal proliferation have been identified in women exposed to high plasma estrogen concentrations and these lesions are associated with thrombotic occlusion. Other structural changes may result in increased vascular permeability, loss of vascular tone and venous stasis. With regard to arterial disease risk, epidemiological information relating to dose effects and joint effects with other risk factors, and studies of pathology and changes in risk factors, suggests that oral contraceptive use per se does not cause arterial disease. It can, nevertheless, synergise very powerfully with subclinical endothelial damage to promote arterial occlusion. Accordingly, the prothrombotic effects of the oral contraceptive estrogen intervene in a cycle of endothelial damage and repair which would otherwise remain clinically silent or would ultimately progress - in, for example, the presence of cigarette smoking or hypertension - to atherosclerosis. Future work in this area should focus on modification of the effects of established risk factors by oral contraceptive use rather than modification of the supposed risk of oral contraceptive use by established risk factors. Attempts to understand vascular occlusion in oral contraceptive users in terms of the general features of VTE or with reference to atherosclerosis may be limiting, and future work needs to acknowledge that such occlusions may have unique features. Unequivocal identification of the mechanisms involved would contribute considerably to the alleviation of fears over vascular disease and to the development of even safer formulations.

Serum C-reactive protein and fibrinogen concentrations and self-reported angina pectoris and myocardial infarction: findings from National Health and Nutrition Examination Survey III

C-reactive protein may predict the risk of cardiovascular disease, but its association with angina pectoris in the general population has not been clearly established, however. We used data from National Health and Nutrition Examination Survey III conducted from 1988-1994 to examine the associations between serum C-reactive protein and plasma fibrinogen concentrations and self-reported angina pectoris and myocardial infarction among 7,948 U.S. men and women aged 40 years and older. C-reactive protein and fibrinogen concentrations were moderately correlated (r = 0.43). After adjustment for age, sex, race or ethnicity, education, smoking status, systolic blood pressure, serum cholesterol, high-density lipoprotein cholesterol, history of diabetes mellitus, body mass index, and physical activity, fibrinogen (but not C-reactive protein) concentration was significantly associated with self-reported angina pectoris. Neither fibrinogen or C-reactive protein concentrations were significantly associated with angina pectoris when entered in the model simultaneously. C-reactive protein and fibrinogen concentrations were positively associated with myocardial infarction when entered separately into models, but only C-reactive protein concentration was significantly associated with myocardial infarction when both variables were entered simultaneously. These cross-sectional data showed a significant positive association between C-reactive protein concentration and myocardial infarction but not self-reported angina pectoris in the U.S. population.

Fibrinogen and cardiovascular risk

The hypothesis that fibrinogen is closely related to cardiovascular risk has been strengthened through the results of various lines of research, which this review will aim to unravel. Several prospective epidemiological studies convincingly show elevated fibrinogen to represent a major, independent cardiovascular risk factor. Cross-sectional studies strongly associate fibrinogen and conventional cardiovascular risk factors. Clinical cohort studies demonstrate that increased fibrinogen is also a risk factor for the sequelae of cardiovascular disease. Our knowledge about the determinants of the variable plasma level of fibrinogen in health and disease is incomplete. Understanding of the mechanisms that might be involved in the atherothrombogenic action of fibrinogen is also fragmentary. Fibrinogen strongly affects blood coagulation, blood rheology and platelet aggregation. In addition, it has direct effects on the vascular wall and is a prominent acute phase reactant. All of these phenomena might constitute pathophysiological mechanisms involved in the association between fibrinogen and cardiovascular events. Their relative importance is unclear at present. Even though many crucial questions await conclusive answers, little doubt exists that fibrinogen represents a major, independent risk factor.

Fibrinolytic variables and cardiovascular prognosis in patients with stable angina pectoris treated with verapamil or metoprolol. Results from the Angina Prognosis study in Stockholm

BACKGROUND

Disturbed fibrinolytic function may influence the progression of coronary atherosclerosis and contribute to thrombotic cardiovascular (CV) events.

METHODS AND RESULTS

In the Angina Prognosis Study in Stockholm (APSIS), patients with stable angina pectoris were studied prospectively during double-blind treatment with metoprolol or verapamil. Various measures of fibrinolytic function were studied in 631 (of 809) patients. During a median follow-up time of 3.2 years (2132 patient-years), 32 patients suffered a CV death, 21 had a nonfatal myocardial infarction (MI), and 77 underwent revascularization. Plasma levels of tissue plasminogen activator (TPA) activity and antigen (ag), plasminogen activator inhibitor (PAI-1) activity at test, and TPA responses to exercise were determined at baseline and after 1 month's treatment and were related to subsequent fatal and nonfatal CV events. Univariate Cox regression analysis revealed that elevated levels of TPA-ag at rest (P < .05), high PAI-1 activity (P < .05), and low TPA-ag responses to exercise (P < .05) were associated with increased risk of subsequent CV death. After adjustment for baseline risk factors, TPA-ag independently predicted CV death or MI. In addition, PAI-1 activity independently predicted CV death or MI in male patients. Verapamil treatment was associated with a 10% decrease of TPA-ag levels and metoprolol treatment with a 2% increase (P < .001 for treatment difference).

CONCLUSIONS

Plasma TPA-ag levels at rest, and among male patients PAI-1 activity as well, independently predict subsequent CV death or MI in patients with stable angina pectoris.