N-3 polyunsaturated fatty acids in heart failure: mechanisms and recent clinical evidence.

Over the past 20 years, there has been significant progress in our knowledge of the pathophysiology of heart failure (HF) with consequent considerable development of both pharmacological and non pharmacological approaches. Despite improved therapeutic strategies, HF still remains burdensome in terms of mortality, quality of life, and hospitalization costs. A new and promising medical treatment to improve survival in HF patients stems from the recent results of the Italian study, Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto Miocardico-Heart Failure (GISSI-HF). GISSI-HF was a randomized, large scale, double-blind, placebo-controlled trial showing that n-3 PUFA (850-882 mg/d) reduced mortality and admission to the hospital for cardiovascular reasons in patients with chronic heart failure (HF) who were already receiving recommended therapies. The clinical benefit observed in GISSI-HF seemed to be mediated prominently by the antiarrhythmic effects of n-3 PUFA, though an effect on mechanisms related to HF progression cannot be excluded. This article presents the results of GISSI-HF study and reviews the previous clinical evidence on n-3 PUFA and risk of heart failure and discusses in depth the potential mechanisms through which n-3 PUFA treatment can improve clinical outcome in HF patients.

Systematically missing confounders in individual participant data meta-analysis of observational cohort studies.

One difficulty in performing meta-analyses of observational cohort studies is that the availability of confounders may vary between cohorts, so that some cohorts provide fully adjusted analyses while others only provide partially adjusted analyses. Commonly, analyses of the association between an exposure and disease either are restricted to cohorts with full confounder information, or use all cohorts but do not fully adjust for confounding. We propose using a bivariate random-effects meta-analysis model to use information from all available cohorts while still adjusting for all the potential confounders. Our method uses both the fully adjusted and the partially adjusted estimated effects in the cohorts with full confounder information, together with an estimate of their within-cohort correlation. The method is applied to estimate the association between fibrinogen level and coronary heart disease incidence using data from 154,012 participants in 31 cohorts

Plasma fibrinogen level and the risk of major cardiovascular diseases and nonvascular mortality: an individual participant meta-analysis.

CONTEXT: Plasma fibrinogen levels may be associated with the risk of coronary heart disease (CHD) and stroke. OBJECTIVE: To assess the relationships of fibrinogen levels with risk of major vascular and with risk of nonvascular outcomes based on individual participant data. DATA SOURCES: Relevant studies were identified by computer-assisted searches, hand searches of reference lists, and personal communication with relevant investigators. STUDY SELECTION: All identified prospective studies were included with information available on baseline fibrinogen levels and details of subsequent major vascular morbidity and/or cause-specific mortality during at least 1 year of follow-up. Studies were excluded if they recruited participants on the basis of having had a previous history of cardiovascular disease; participants with known preexisting CHD or stroke were excluded. DATA EXTRACTION: Individual records were provided on each of 154,211 participants in 31 prospective studies. During 1.38 million person-years of follow-up, there were 6944 first nonfatal myocardial infarctions or stroke events and 13,210 deaths. Cause-specific mortality was generally available. Analyses involved proportional hazards modeling with adjustment for confounding by known cardiovascular risk factors and for regression dilution bias. DATA SYNTHESIS: Within each age group considered (40-59, 60-69, and > or =70 years), there was an approximately log-linear association with usual fibrinogen level for the risk of any CHD, any stroke, other vascular (eg, non-CHD, nonstroke) mortality, and nonvascular mortality. There was no evidence of a threshold within the range of usual fibrinogen level studied at any age. The age- and sex- adjusted hazard ratio per 1-g/L increase in usual fibrinogen level for CHD was 2.42 (95% confidence interval [CI], 2.24-2.60); stroke, 2.06 (95% CI, 1.83-2.33); other vascular mortality, 2.76 (95% CI, 2.28-3.35); and nonvascular mortality, 2.03 (95% CI, 1.90-2.18). The hazard ratios for CHD and stroke were reduced to about 1.8 after further adjustment for measured values of several established vascular risk factors. In a subset of 7011 participants with available C-reactive protein values, the findings for CHD were essentially unchanged following additional adjustment for C-reactive protein. The associations of fibrinogen level with CHD or stroke did not differ substantially according to sex, smoking, blood pressure, blood lipid levels, or several features of study design. CONCLUSIONS: In this large individual participant meta-analysis, moderately strong associations were found between usual plasma fibrinogen level and the risks of CHD, stroke, other vascular mortality, and nonvascular mortality in a wide range of circumstances in healthy middle-aged adults. Assessment of any causal relevance of elevated fibrinogen levels to disease requires additional research.

A randomized clinical trial of high-intensity warfarin vs. conventional antithrombotic therapy for the prevention of recurrent thrombosis in patients with the antiphospholipid syndrome (WAPS).

BACKGROUND: The optimal intensity of oral anticoagulation for the prevention of recurrent thrombosis in patients with antiphospholipid antibody syndrome is uncertain. Retrospective studies show that only high-intensity oral anticoagulation [target international normalized ratio (INR) >3.0] is effective but a recent randomized clinical trial comparing high (INR range 3.0-4.0) vs. moderate (INR 2.0-3.0) intensities of anticoagulation failed to confirm this assumption. METHODS: We conducted a randomized trial in which 109 patients with antiphospholipid syndrome (APS) and previous thrombosis were given either high-intensity warfarin (INR range 3.0-4.5, 54 patients) or standard antithrombotic therapy (warfarin, INR range 2.0-3.0 in 52 patients or aspirin alone, 100 mg day(-1) in three patients) to determine whether intensive anticoagulation is superior to standard treatment in preventing symptomatic thromboembolism without increasing the bleeding risk. RESULTS: The 109 patients enrolled in the trial were followed up for a median time of 3.6 years. Mean INR during follow-up was 3.2 (SD 0.6) in the high-intensity warfarin group and 2.5 (SD 0.3) (P < 0.0001) in the conventional treatment patients given warfarin. Recurrent thrombosis was observed in six of 54 patients (11.1%) assigned to receive high-intensity warfarin and in three of 55 patients (5.5%) assigned to receive conventional treatment [hazard ratio for the high intensity group, 1.97; 95% confidence interval (CI) 0.49-7.89]. Major and minor bleeding occurred in 15 patients (two major) (27.8%) assigned to receive high-intensity warfarin and eight (three major) (14.6%) assigned to receive conventional treatment (hazard ratio 2.18; 95% CI 0.92-5.15). CONCLUSIONS: High-intensity warfarin was not superior to standard treatment in preventing recurrent thrombosis in patients with APS and was associated with an increased rate of minor hemorrhagic complications.

Antiarrhythmic mechanisms of n-3 PUFA and the results of the GISSI-Prevenzione trial.

The purpose of this paper is twofold: on the one hand, to confirm the positive results on n-3 PUFA from the overall results Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto Miocardico (GlSSI)-Prevenzione trial; on the other, to summarize and describe how the results of an important trial can help generate hypotheses either on mechanisms of action or on differential results in particular subgroups of patients, as well as test the pathophysiological hypotheses that have accompanied in the years the story of the hypothesized mechanisms of action of a drug. GISSI-Prevenzione was conceived as a pragmatic population trial on patients with recent myocardial infarction and it was conducted in the framework of the Italian public health system. In GISSI-Prevenzione, 11,323 patients were enrolled in a clinical trial aimed at testing the effectiveness of n-3 polyunsaturated fatty acids (PUFA) and vitamin E. Patients were invited to follow Mediterranean dietary habits, and were treated with up-to-date preventive pharmacological interventions. Long-term n-3 PUFA at 1 g daily, but not vitamin E at 300 mg daily, was beneficial for death and for combined death, non-fatal myocardial infarction, and stroke. All the benefit, however, was attributable to the decrease in risk for overall (-20%), cardiovascular (-30%), and sudden death (-45%). At variance from the orientation of a scientific scenario largely dominated by the "cholesterol-heart hypothesis", GISSI-Prevenzione results indicate n-3 PUFA (virtually devoid of any cholesterol-lowering effect) as a relevant pharmacological treatment for secondary prevention after myocardial infarction.

[Omega-3 polyunsaturated fatty acids and cardiovascular diseases]. / Gli acidi grassi polinsaturi omega-3 e le malattie cardiovascolari.

Population studies indicate omega-3 that a high fish intake, such as reported in the early Eskimo and Japanese studies, is associated with a low mortality from coronary heart disease (CHD). These effects have been associated with measurable effects on a series of established and possible risk factors. In most of the later population studies much lower daily intake of fish has been observed, such intake having only small or not even measurable effects on established risk factors. Still, their association with reduced CHD mortality, particularly sudden cardiac death seem to be reasonably well established. Beneficial effects are found at a level of consumption of about 30 g per day or 1 fish meal per week compared with populations rarely or never consuming fish. Such findings are also reflected in studies including analysis of fatty acid composition in adipose tissue and cell membranes. Fish consumption may be a marker for a healthier lifestyle or, alternatively, fish consumers may be at higher self-perceived risk for CHD and are therefore eating fish to reduce their high baseline risk. Despite all these limitations, the population studies seem to indicate that a high fish intake is associated with a low mortality from CHD. GISSI-Prevenzione was conceived as a population, pragmatic trial on patients with recent myocardial infarction and it was conducted in the framework of the Italian public health system. In GISSI-Prevenzione, 11,323 patients were enrolled in a clinical trial aimed at testing the effectiveness of omega-3 PUFA and vitamin E. Patients were invited to follow Mediterranean dietary habits, and were treated with up-to-date preventive pharmacological interventions. Long-term omega-3 PUFA 1 g daily, but not vitamin E 300 mg daily, was beneficial for death and for combined death, non-fatal myocardial infarction, and stroke. All the benefit, however, was attributable to the decrease in risk for overall, cardiovascular, cardiac, coronary, and sudden death. In GISSI-Prevenzione, long-term administration of omega-3 PUFA (1 g daily) significantly decreased the risk of overall (-20%), cardiovascular (-30%), and sudden death (-45%). At variance from the orientation of a scientific scenario largely dominated by the "cholesterol-heart hypothesis", GISSI-Prevenzione results indicate omega-3 PUFA (virtually devoid of any cholesterol-lowering effect) as a relevant pharmacological treatment for secondary prevention after myocardial infarction.

Mediterranean diet and all-causes mortality after myocardial infarction: results from the GISSI-Prevenzione trial.

OBJECTIVE: To ascertain whether simple dietary advice to increase the consumption of Mediterranean foods, given in a clinical setting, leads to reduced mortality after a myocardial infarction. DESIGN: Data were used from the GISSI-Prevenzione clinical trial, analysed as a cohort study with adjustment for treatment allocation. SETTING: A total of 172 centres in Italy. SUBJECTS: A total of 11323 men and women with myocardial infarction. All subjects received advice to increase their consumption of fish, fruit, raw and cooked vegetables and olive oil. MEASUREMENTS: The intakes of the five foods were assessed at baseline, 6, 18 and 42 months. Associations of food intakes, a combined dietary score, and the risk of death over 6.5 y were estimated adjusting for several non-dietary variables, using pooled logistic regression. RESULTS: Subjects generally improved their diet according to the advice given. All foods were associated with a significant reduction in risk of death. Compared with people in the worst dietary score quarter, the odds ratio for those in the best score quarter was 0.51 (95% CI 0.44-0.59). A good diet had a protective effect in sub-groups defined by age, sex, smoking, randomized treatment and concomitant drug therapy. CONCLUSIONS: Myocardial infarction patients can respond positively to simple dietary advice, and this can be expected to lead to a substantial reduction in the risk of early death. Regardless of any drug treatment prescribed, clinicians should routinely advise patients with myocardial infarction to increase their frequency of consumption of Mediterranean foods.

Assessment of absolute risk of death after myocardial infarction by use of multiple-risk-factor assessment equations: GISSI-Prevenzione mortality risk chart.

AIMS: To present and discuss a comprehensive and ready to use prediction model of risk of death after myocardial infarction based on the very recently concluded follow-up of the large GISSI-Prevenzione cohort and on the integrated evaluation of different categories of risk factors: those that are non-modifiable, and those related to lifestyles, co-morbidity, background, and other conventional clinical complications produced by the index myocardial infarction. METHODS: The 11-324 men and women recruited in the study within 3 months from their index myocardial infarction have been followed-up to 4 years. The following risk factors have been used in a Cox proportional hazards model: non-modifiable risk factors: age and sex; complications after myocardial infarction: indicators of left ventricular dysfunction (signs or symptoms of acute left ventricular failure during hospitalization, ejection fraction, NYHA class and extent of ventricular asynergy at echocardiography), indicators of electrical instability (number of premature ventricular beats per hour, sustained or repetitive arrhythmias during 24-h Holter monitoring), indicators of residual ischaemia (spontaneous angina pectoris after myocardial infarction, Canadian Angina Classification class, and exercise testing results); cardiovascular risk factors: smoking habits, history of diabetes mellitus and arterial hypertension, systolic and diastolic blood pressure, blood total and HDL cholesterol, triglycerides, fibrinogen, leukocytes count, intermittent claudication, and heart rate. Multiple regression modelling was assessed by receiver operating characteristic (ROC) analysis. Generalizability of the models was assessed through cross validation and bootstrapping techniques. POPULATION AND RESULTS: During the 4 years of follow-up, a total of 1071 patients died. Age and left ventricular dysfunction were the most relevant predictors of death. Because of pharmacological treatments, total blood cholesterol, triglycerides, and blood pressure values were not significantly associated with prognosis. Sex-specific prediction equations were formulated to predict risk of death according to age, simple indicators of left ventricular dysfunction, electrical instability, and residual ischaemia along with the following cardiovascular risk factors: smoking habits, history of diabetes mellitus and arterial hypertension, blood HDL cholesterol, fibrinogen, leukocyte count, intermittent claudication, and heart rate. The predictive models produced on the basis of information available in the routine conditions of clinical care after myocardial infarction provide ready to use and highly discriminant criteria to guide secondary prevention strategies. CONCLUSIONS AND IMPLICATIONS: Besides documenting what should be the preferred and practicable focus of clinical attention for today's patients, the experience of GISSI-Prevenzione suggests that periodically and prospectively collected databases on naturalistic' cohorts could be an important option for updating and verifying the impact of guidelines, which should incorporate the different components of the complex profile of cardiovascular risk. The GISSI Prevenzione risk function is a simple tool to predict risk of death and to improve clinical management of subjects with recent myocardial infarction. The use of predictive risk algorithms can favour the shift from medical logic, based on the treatment of single risk factors, to one centred on the patient as a whole as well as the tailoring of medical interventions according to patients' overall risk.

Cost-effectiveness analysis of n-3 polyunsaturated fatty acids (PUFA) after myocardial infarction: results from Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto (GISSI)-Prevenzione Trial.

OBJECTIVE: To estimate the cost effectiveness of treatment with n-3 polyunsaturated fatty acids (PUFA) for secondary prevention after myocardial infarction (MI). DESIGN AND SETTING: The cost-effectiveness analysis of n-3 PUFA treatment after MI was based on morbidity and mortality data and the use of resources obtained prospectively during the 3.5 year follow-up period of the Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto (GISSI)-Prevenzione study. The cost-effectiveness analysis took into account the incremental number of life-years gained and the incremental costs for hospital admissions, diagnostic tests and drugs, applying a 5% discount rate. The value for money of n-3 PUFA treatment was assessed using the cost-effectiveness ratio and the number needed to treat (NNT) approach. PERSPECTIVE: Third-party payer. MAIN OUTCOME MEASURES AND RESULTS: The incremental cost-effectiveness ratio for n-3 PUFA in the basecase scenario was 24,603 euro (EUR, 1999 values) per life-year gained (95% confidence interval: 22,646 to 26,930). Sensitivity analysis included the analysis of extremes, producing estimates varying from EUR15,721 to EUR52,524 per life-year gained. 172 patients would need to be treated per year with n-3 PUFA, at an annual cost of EUR68,000, in order to save 1 patient. This is comparable with the NNT value, and associated annual cost for simvastatin, but less costly than that for pravastatin. CONCLUSIONS: The cost effectiveness of long term treatment with n-3 PUFA is comparable with other drugs recently introduced in the routine care of secondary prevention after MI. Since the clinical benefit provided by n-3 PUFA is additive, this therapy should be added to the established routine practice, with additive costs.

Efficacy of n-3 polyunsaturated fatty acids after myocardial infarction: results of GISSI-Prevenzione trial. Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto Miocardico.

Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto Miocardio (GISSI)-Prevenzione was conceived as a population, pragmatic trial on patients with recent myocardial infarctions conducted in the framework of the Italian public health system. In GISSI-Prevenzione, patients were invited to follow Mediterranean dietary habits, and were treated with up-to-date preventive pharmacological interventions. Long-term n-3 PUFA (1 g daily) but not vitamin E (300 mg daily) was beneficial for death and for combined death, nonfatal myocardial infarction, and stroke. All the benefit, however, was attributable to the decrease in risk for overall, cardiovascular, cardiac, coronary, and sudden death. At variance with the orientation of a scientific scenario largely dominated by the "cholesterol-heart hypothesis," GISSI-Prevenzione results indicate n-3 PUFA (virtually devoid of any cholesterol-lowering effect) as a relevant pharmacological treatment for secondary prevention after myocardial infarction. As to the relevance and comparability of GISSI-Prevenzione results, up to 5.7 lives could be saved every 1000 patients with previous myocardial infarction treated with n-3 PUFA (1 g daily) per year. Such a result is comparable to that observed in the Long-Term Intervention with Pravastatin in Ischaemic Disease (LIPID) trial, where 5.2 lives could be saved per 1000 hypercholesterolemic, coronary heart disease patients treated with pravastatin for 1 yr. The choice of a relatively low-dose regimen (1-g capsule daily) more acceptable for long-term treatment in a population of patients following Mediterranean dietary habits, and the pattern of effects seen in GISSI-Prevenzione (namely, reduction of overall mortality with no decrease in the rate of nonfatal myocardial infarction) all strongly suggest that n-3 PUFA treatment should be considered a recommended new component of secondary prevention. The importance of this combined/additive effect is further suggested by the analyses of the interplay between diet and n-3 PUFA: There is an interesting direct correlation between size of the effect and "correctness" of background diets. It can be anticipated that a conceptual barrier must be overcome: A "dietary drug" should be added to "dietary advice," which remains fundamental to allow this statement to become true in clinical practice.

n-3 polyunsaturated fatty acids and cardiovascular diseases.

An expert round table discussion on the relationship between intake of n-3 polyunsaturated fatty acids (PUFA) mainly of marine sources and coronary heart disease at the 34th Annual Scientific Meeting of European Society for Clinical Investigation came to the following conclusions: 1. Consumption of 1-2 fish meals/wk is associated with reduced coronary heart disease (CHD) mortality. 2. Patients who have experienced myocardial infarction have decreased risk of total, cardiovascular, coronary, and sudden death by drug treatment with 1 g/d of ethylesters of n-3 PUFA, mainly as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The effect is present irrespective of high or low traditional fish intake or simultaneous intake of other drugs for secondary CHD prevention. n-3 PUFA may also be given as fatty fish or triglyceride concentrates. 3. Patients who have experienced coronary artery bypass surgery with venous grafts may reduce graft occlusion rates by administration of 4 g/d of n-3 PUFA. 4. Patients with moderate hypertension may reduce blood pressure by administration of 4 g/d of n-3 PUFA. 5. After heart transplantation, 4 g/d of n-3 PUFA may protect against development of hypertension. 6. Patients with dyslipidemia and or postprandial hyperlipemia may reduce their coronary risk profile by administration of 1-4 g/d of marine n-3 PUFA. The combination with statins seems to be a potent alternative in these patients. 7. There is growing evidence that daily intake of up to 1 energy% of nutrients from plant n-3 PUFA (alpha-linolenic acid) may decrease the risk for myocardial infarction and death in patients with CHD. This paper summarizes the conclusions of an expert panel on the relationship between n-3 PUFA and CHD. The objectives for the experts were to formulate scientifically sound conclusions on the effects of fish in the diet and the administration of marine n-3 PUFA, mainly eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3), and eventually of plant n-3 PUFA, alpha-linolenic acid (ALA, 18:3n-3), on primary and secondary prevention of CHD. Fish in the diet should be considered as part of a healthy diet low in saturated fats for everybody, whereas additional administration of n-3 PUFA concentrates could be given to specific groups of patients. This workshop was organized on the basis of questions sent to the participants beforehand, on brief introductions by the participants, and finally on discussion and analysis by a group of approximately 40 international scientists in the fields of nutrition, cardiology, epidemiology, lipidology, and thrombosis.

Antioxidant vitamins and prevention of cardiovascular disease: epidemiological and clinical trial data.

Naturally occurring antioxidants such as vitamin E, beta-carotene, and vitamin C can inhibit the oxidative modification of low density lipoproteins. This action could positively influence the atherosclerotic process and, as a consequence, the progression of coronary heart disease. A wealth of experimental studies provide a sound biological rationale for the mechanisms of action of antioxidants, whereas epidemiologic studies strongly sustain the "antioxidant hypothesis." To date, however, clinical trials with beta-carotene supplements have been disappointing, and their use as a preventive intervention for cancer and coronary heart disease should be discouraged. Only scanty data from clinical trials are available for vitamin C. As to vitamin E, discrepant results have been obtained by the Alpha-Tocopherol, Beta Carotene Cancer Prevention Study with a low-dose vitamin E supplementation (50 mg/d) and the Cambridge Heart Antioxidant Study (400-800 mg/d). The results of the GISSI-Prevenzione (300 mg/d) and HOPE (400 mg/d) trials suggest the absence of relevant clinical effects of vitamin E on the risk of cardiovascular events. Currently ongoing are several large-scale clinical trials that will help in clarifying the role of vitamin E in association with other antioxidants in the prevention of atherosclerotic coronary disease.

Cardiovascular risk changes after lipid lowering medications: are they predictable?

Changes in cardiovascular risk after lipid lowering medications are generally expressed as relative risk reduction (RRR). Comparison of the eight major studies published in this last decade indicates that the RRRs ranged from a minimum (19%) for the LRC Study with cholestyramine, to maximal values of 34-37% for studies such as the HHS, 4S and AFCAPS/TexCAPS. These RRRs were barely related to the drugs' effects on major lipid parameters, e.g. LDL cholesterol. Instead, by using the absolute risk reduction (ARRs), easily calculated by subtracting the percentage end points for the drug treated from these values of the placebo group in all studies, a wide range of values was found, also adding to the series a non pharmacological study such as the Program on the Surgical Control of the Hyperlipidemias (POSCH) trial. Calculated ARRs were directly correlated to the baseline cardiovascular (CV) risk in all studies, thus allowing an easy prediction of a drug's effect in the selected population. Drugs with different mechanisms (statins, fibrates and resins) all fitted into this correlation nomogram. These findings clearly indicate that the CV effects of lipid changes, such as LDL cholesterol and triglyceride reduction or HDL rises, are in the same direction, and can be well predicted. The similar, almost identical behavior of drugs affecting LDL cholesterolemia to a different degree or not at all, indicates that novel approaches should be sought to improve risk reduction and that individual therapy should be ideally pursued, rather than a 'one drug' approach.

Beta-carotene, vitamin C, and vitamin E and cardiovascular diseases.

Observational studies have shown an inverse relationship between consumption of fruits and vegetables high in beta-carotene, vitamins C and E, and ischemic heart disease (IHD) and stroke. In large observational studies, beta- carotene reduced the risk of IHD events in men, particularly in smokers. In contrast, four large randomized trials did not reveal a reduction in cardiovascular events with beta-carotene use, and may, in fact, increase IHD and total mortality in male smokers. There have been only a few large observational studies and one randomized trial with vitamin C, which have shown no beneficial or deleterious impact of this vitamin on cardiovascular events. Most large observational studies have shown an inverse relationship between vitamin E and IHD. However, a meta-analysis of the four randomized trials done in Europe and America involving a total of 51,000 participants allocated to vitamin E or placebo for 1.4 to 6 years, did not demonstrate a reduction in cardiovascular and IHD mortality and nonfatal myocardial infarction. Currently, there are no data to support the use of these vitamins to reduce the risk of cardiovascular events. Trials are in progress to determine whether a longer duration of administration of vitamin E or the association of vitamin E with cofactors may reduce cardiovascular events.

Cholesterol reduction and stroke occurrence: an overview of randomized clinical trials.

We performed a meta-analysis of randomized clinical trials of more than 6 months duration to describe how fatal and nonfatal strokes are related to cholesterol lowering and to the type of intervention. A total of 41 individual trials including approximately 80,000 subjects and followed for an average of about 4 years were included in the overview. There was a 16% (95% CI, 7-25%) reduction in risk of stroke among treated patients compared to control patients (test for heterogeneity, p = 0.76). When trials that used different interventions were separately examined, a significant reduction in stroke occurrence was observed only for those using statins as active treatment (risk reduction 23%; 95% CI 13-33%). A variance-weighted regression analysis of the logarithmic odds ratios for stroke incidence against the percentage of cholesterol reduction indicated that a reduction of fatal and nonfatal stroke can be obtained for a cholesterol reduction of 9% (95% CI 6.8-13.6%). The combined data of primary and secondary prevention trials indicate that a large reduction of blood cholesterol, achievable with statin drugs, can reduce the incidence of stroke.

Antioxidant vitamins and prevention of cardiovascular disease: laboratory, epidemiological and clinical trial data.

Naturally occurring antioxidants like vitamin E, beta-carotene, and vitamin C can inhibit the oxidative modification of low-density lipoproteins. This action could positively influence the atherosclerotic process and, as a consequence, the progression of coronary heart disease. A wealth of experimental studies provide a sound biological rationale for the mechanisms of action of antioxidants, whereas epidemiological studies strongly sustain the 'antioxidant hypothesis'. To data, however, clinical trials with beta-carotene supplements have been disappointing and their use as a preventive intervention for cancer and coronary heart disease should be discouraged. Only scant data from clinical trials are available for vitamin C. As for vitamin E, discrepant results have been obtained by the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study with a low-dose vitamin E supplementation (50 mg daily) and the Cambridge Heart Antioxidant Study (400-800 mg daily). Currently ongoing are several large-scale clinical trials that will help in clarifying the role of vitamin E in the prevention of atherosclerotic coronary disease.

The risk of thrombosis in patients with lupus anticoagulants is predicted by their specific coagulation profile.

Lupus anticoagulants belong to the family of antiphospholipid antibodies. They include two phospholipid-dependent inhibitors of coagulation that may be distinguished on the basis of specific coagulation profiles generated from the comparison of the ratios of the Kaolin Clotting Time (KCT) and the dilute Russell's Viper Venom Time (dRVVT): when the ratio of the KCT exceeds that of the dRVVT, the plasma is allocated to the "KCT" coagulation profile, when the opposite occurs, the plasma is defined to belong to the "dRVVT" coagulation profile group. We prospectively followed-up a historical cohort of 100 consecutive patients with lupus anticoagulants referred to our Institution between January 1988 and October 1997 to investigate the relationship between their coagulation profile at diagnosis and the development of thrombosis during a median follow-up time of 37.5 months (range 1-115 months). Fifty-six patients were allocated to the "dRVVT" coagulation profile, whereas the other 44 displayed the "KCT" profile. Lupus anticoagulants were transient in 17 patients, without differences between the two groups. None of these patients developed clinical events before disappearance of the phospholipid-dependent inhibitors of coagulation. The 83 cases with persistent lupus anticoagulants consistently displayed the same coagulation profile they had been allocated to at entry. Fourteen patients developed 18 thromboembolic events during the follow-up, with an overall rate of thrombosis of 4.2% patients-year. Twelve of them belonged to the "dRVVT" coagulation profile, whereas the other 2 to the "KCT" profile (p = 0.03). The "dRVVT" coagulation profile gave an odds ratio of thrombosis of 5.25 (95% confidence interval [C.I]: 1.17-23.50). Ten of the 14 patients who developed thrombosis during follow-up had already experienced thrombosis: a previous thrombotic event caused an odds ratio of recurrency of 2.72 (95% C.I.: 0.85-8.73) (p = 0.09). By multivariate analysis, the "dRVVT" coagulation profile was still associated with a trend to a higher risk of thrombosis, but the difference did not reach statistical significance. Increased levels of anticardiolipin antibodies (> 40 GPL and/or MPL units) were found in all the 14 patients (p = 0.0064). The "KCT" coagulation profile was significantly associated (p = 0.005) with moderate thrombocytopenia (platelets 50-150 X 10(9)/l). Neither profile was found to represent a risk factor for the development of recurrent miscarriages, neoplastic diseases and death. In conclusion, the "dRVVT" profile appears to have predictive value with respect to the thrombotic complications suffered by patients with antiphospholipid antibodies.