Neuraxial block, death and serious cardiovascular morbidity in the POISE trial

BACKGROUND

This post hoc analysis aimed to determine whether neuraxial block was associated with a composite of cardiovascular death, non-fatal myocardial infarction (MI) and non-fatal cardiac arrest within 30 days of randomization in POISE trial patients.

METHODS

A total of 8351 non-cardiac surgical patients at high risk of cardiovascular complications were randomized to β-blocker or placebo. Neuraxial block was defined as spinal, lumbar or thoracic epidural anaesthesia. Logistic regression, with weighting using estimated propensity scores, was used to determine the association between neuraxial block and primary and secondary outcomes.

RESULTS

Neuraxial block was associated with an increased risk of the primary outcome [287 (7.3%) vs 229 (5.7%); odds ratio (OR), 1.24; 95% confidence interval (CI), 1.02-1.49; P=0.03] and MI [230 (5.9%) vs 177 (4.4%); OR, 1.32; 95% CI, 1.07-1.64; P=0.009] but not stroke [23 (0.6%) vs 32 (0.8%); OR, 0.76; 95% CI, 0.44-1.33; P=0.34], death [96 (2.5%) vs 111 (2.8%); OR, 0.87; 95% CI, 0.65-1.17; P=0.37] or clinically significant hypotension [522 (13.4%) vs 484 (12.1%); OR, 1.13; 95% CI, 0.99-1.30; P=0.08]. Thoracic epidural with general anaesthesia was associated with a worse primary outcome than general anaesthesia alone [86 (12.1%) vs 119 (5.4%); OR, 2.95; 95% CI, 2.00-4.35; P<0.001].

CONCLUSIONS

In patients at high risk of cardiovascular morbidity, neuraxial block was associated with an increased risk of adverse cardiovascular outcomes, which could be causal or because of residual confounding.

Increased cardiovascular risk after pre-eclampsia in women with dysglycaemia

AIMS

Compared with women with uncomplicated pregnancies, women with a history of pre-eclampsia have two to five times the risk of cardiovascular disease. It is not known whether this risk is related to albuminuria, a known cardiovascular risk factor that is part of the definition of pre-eclampsia and that often persists after delivery. Our objective was to determine if the high risk of cardiovascular disease in women with pre-eclampsia is accounted for by known cardiovascular risk factors including albuminuria.

METHODS

We performed a cross-sectional analysis of 4080 dysglycaemic women enrolled in a large randomized controlled trial who provided an obstetric history and had at least one delivery. Blood pressure, height, weight, waist circumference and hip circumference were measured. An oral glucose tolerance test, lipids, an electrocardiogram and an albumin/creatinine ratio from a first morning urine sample were obtained.

RESULTS

There were 3613 women with no history of pre-eclampsia during their pregnancies, 108 with severe pre-eclampsia and 359 with non-severe pre-eclampsia. Women with a history of severe pre-eclampsia had higher rates of previous cardiovascular disease than women with non-severe pre-eclampsia or women without pre-eclampsia (87, 72 and 72%, P = 0.0019). The high risk of previous cardiovascular disease in women with a history of severe pre-eclampsia (odds ratio 2.67, 95% CI 1.52-4.70) persisted after adjustment for albuminuria (odds ratio 2.74, 95% CI 1.55-4.83) and also after adjusting for other covariates including albuminuria (odds ratio 3.03, 95% CI 1.69-5.44).

CONCLUSION

Even after accounting for cardiovascular risk factors including albuminuria, a history of severe pre-eclampsia is independently associated with a threefold higher risk of cardiovascular disease.

Effects of the angiotensin-receptor blocker telmisartan on cardiovascular events in high-risk patients intolerant to angiotensin-converting enzyme inhibitors: a randomised controlled trial

BACKGROUND

Angiotensin-converting enzyme (ACE) inhibitors reduce major cardiovascular events, but are not tolerated by about 20% of patients. We therefore assessed whether the angiotensin-receptor blocker telmisartan would be effective in patients intolerant to ACE inhibitors with cardiovascular disease or diabetes with end-organ damage.

METHODS

After a 3-week run-in period, 5926 patients, many of whom were receiving concomitant proven therapies, were randomised to receive telmisartan 80 mg/day (n=2954) or placebo (n=2972) by use of a central automated randomisation system. Randomisation was stratified by hospital. The primary outcome was the composite of cardiovascular death, myocardial infarction, stroke, or hospitalisation for heart failure. Analyses were done by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00153101.

FINDINGS

The median duration of follow-up was 56 (IQR 51-64) months. All randomised patients were included in the efficacy analyses. Mean blood pressure was lower in the telmisartan group than in the placebo group throughout the study (weighted mean difference between groups 4.0/2.2 [SD 19.6/12.0] mm Hg). 465 (15.7%) patients experienced the primary outcome in the telmisartan group compared with 504 (17.0%) in the placebo group (hazard ratio 0.92, 95% CI 0.81-1.05, p=0.216). One of the secondary outcomes-a composite of cardiovascular death, myocardial infarction, or stroke-occurred in 384 (13.0%) patients on telmisartan compared with 440 (14.8%) on placebo (0.87, 0.76-1.00, p=0.048 unadjusted; p=0.068 after adjustment for multiplicity of comparisons and overlap with primary outcome). 894 (30.3%) patients receiving telmisartan were hospitalised for a cardiovascular reason, compared with 980 (33.0%) on placebo (relative risk 0.92, 95% CI 0.85-0.99; p=0.025). Fewer patients permanently discontinued study medication in the telmisartan group than in the placebo group (639 [21.6%] vs 705 [23.8%]; p=0.055); the most common reason for permanent discontinuation was hypotensive symptoms (29 [0.98%] in the telmisartan group vs 16 [0.54%] in the placebo group).

INTERPRETATION

Telmisartan was well tolerated in patients unable to tolerate ACE inhibitors. Although the drug had no significant effect on the primary outcome of this study, which included hospitalisations for heart failure, it modestly reduced the risk of the composite outcome of cardiovascular death, myocardial infarction, or stroke.

FUNDING

Boehringer Ingelheim.

Effects of ramipril and rosiglitazone on cardiovascular and renal outcomes in people with impaired glucose tolerance or impaired fasting glucose: results of the Diabetes REduction Assessment with ramipril and rosiglitazone Medication (DREAM) trial

OBJECTIVE

Impaired glucose tolerance (IGT) and/or impaired fasting glucose (IFG) are risk factors for diabetes, cardiovascular disease (CVD), and kidney disease. We determined the effects of ramipril and rosiglitazone on combined and individual CVD and renal outcomes in people with IGT and/or IFG in the Diabetes REduction Assessment With ramipril and rosiglitazone Medication (DREAM) trial.

RESEARCH DESIGN AND METHODS

A total of 5,269 people aged >or=30 years, with IGT and/or IFG without known CVD or renal insufficiency, were randomized to 15 mg/day ramipril versus placebo and 8 mg/day rosiglitazone versus placebo. A composite cardiorenal outcome and its CVD and renal components were assessed during the 3-year follow-up.

RESULTS

Compared with placebo, neither ramipril (15.7% [412 of 2,623] vs. 16.0% [424 of 2,646]; hazard ratio [HR] 0.98 [95% CI 0.84-1.13]; P = 0.75) nor rosiglitazone (15.0% [394 of 2,635] vs. 16.8% [442 of 2,634]; 0.87 [0.75-1.01]; P = 0.07) reduced the risk of the cardiorenal composite outcome. Ramipril had no impact on the CVD and renal components. Rosiglitazone increased heart failure (0.53 vs. 0.08%; HR 7.04 [95% CI 1.60-31.0]; P = 0.01) but reduced the risk of the renal component (0.80 [0.68-0.93]; P = 0.005); prevention of diabetes was independently associated with prevention of the renal component (P < 0.001).

CONCLUSIONS

Ramipril did not alter the cardiorenal outcome or its components. Rosiglitazone, which reduced diabetes, also reduced the development of renal disease but not the cardiorenal outcome and increased the risk of heart failure.

Venous thromboembolism in association with features of the metabolic syndrome

BACKGROUND

Central obesity, diabetes mellitus, dyslipidaemia and chronic hypertension--features of the metabolic syndrome--have been individually associated with venous thromboembolism (VTE). However, whether each of these factors additively increases the risk of VTE is uncertain.

AIM

To determine whether features of the metabolic syndrome independently increase the risk of VTE.

DESIGN

Prospective cohort study derived from the Heart Outcomes Prevention Evaluation 2 (HOPE-2) randomized clinical trial.

SETTING

One hundred and forty-five clinical centres in 13 countries.

METHODS

We studied 5522 adults aged > or =55 years with cardiovascular disease or diabetes mellitus. At enrollment, 35% had 0-1 features of the metabolic syndrome, 30% had two, 24% had three and 11% had four. We defined symptomatic VTE as an objectively confirmed new episode of deep-vein thrombosis or pulmonary embolism.

RESULTS

VTE occurred in 88 individuals during a median 5.0 years of follow-up. The incidence rate of VTE (per 100 person-years) was 0.30 with 0-1 features, 0.36 with two features, 0.38 with three features and 0.40 with four features of the metabolic syndrome (trend p = 0.43). Relative to the presence of 0-1 features of the metabolic syndrome, the adjusted hazard ratio (95%CI) for VTE was 1.22 (0.71-2.08) with two features, 1.25 (0.70-2.24) with three features, and 1.26 (0.59-2.69) with four features.

DISCUSSION

The number of features of the metabolic syndrome present was not a clinically important risk factor for VTE in older adults with vascular arterial disease.

Effect of rosiglitazone on the frequency of diabetes in patients with impaired glucose tolerance or impaired fasting glucose: a randomised controlled trial

BACKGROUND

Rosiglitazone is a thiazolidinedione that reduces insulin resistance and might preserve insulin secretion. The aim of this study was to assess prospectively the drug's ability to prevent type 2 diabetes in individuals at high risk of developing the condition.

METHODS

5269 adults aged 30 years or more with impaired fasting glucose or impaired glucose tolerance, or both, and no previous cardiovascular disease were recruited from 191 sites in 21 countries and randomly assigned to receive rosiglitazone (8 mg daily; n=2365) or placebo (2634) and followed for a median of 3 years. The primary outcome was a composite of incident diabetes or death. Analyses were done by intention to treat. This trial is registered at ClinicalTrials.gov, number NCT00095654.

FINDINGS

At the end of study, 59 individuals had dropped out from the rosiglitazone group and 46 from the placebo group. 306 (11.6%) individuals given rosiglitazone and 686 (26.0%) given placebo developed the composite primary outcome (hazard ratio 0.40, 95% CI 0.35-0.46; p<0.0001); 1330 (50.5%) individuals in the rosiglitazone group and 798 (30.3%) in the placebo group became normoglycaemic (1.71, 1.57-1.87; p<0.0001). Cardiovascular event rates were much the same in both groups, although 14 (0.5%) participants in the rosiglitazone group and two (0.1%) in the placebo group developed heart failure (p=0.01).

INTERPRETATION

Rosiglitazone at 8 mg daily for 3 years substantially reduces incident type 2 diabetes and increases the likelihood of regression to normoglycaemia in adults with impaired fasting glucose or impaired glucose tolerance, or both.

Clopidogrel plus aspirin versus oral anticoagulation for atrial fibrillation in the Atrial fibrillation Clopidogrel Trial with Irbesartan for prevention of Vascular Events (ACTIVE W): a randomised controlled trial

BACKGROUND

Oral anticoagulation therapy reduces risk of vascular events in patients with atrial fibrillation. However, long-term monitoring is necessary and many patients cannot achieve optimum anticoagulation. We assessed whether clopidogrel plus aspirin was non-inferior to oral anticoagulation therapy for prevention of vascular events.

METHODS

Patients were enrolled if they had atrial fibrillation plus one or more risk factor for stroke, and were randomly allocated to receive oral anticoagulation therapy (target international normalised ratio of 2.0-3.0; n=3371) or clopidogrel (75 mg per day) plus aspirin (75-100 mg per day recommended; n=3335). Outcome events were adjudicated by a blinded committee. Primary outcome was first occurrence of stroke, non-CNS systemic embolus, myocardial infarction, or vascular death. Analyses were by intention-to-treat. This study is registered with ClinicalTrials.gov, number NCT00243178.

RESULTS

The study was stopped early because of clear evidence of superiority of oral anticoagulation therapy. There were 165 primary events in patients on oral anticoagulation therapy (annual risk 3.93%) and 234 in those on clopidogrel plus aspirin (annual risk 5.60%; relative risk 1.44 (1.18-1.76; p=0.0003). Patients on oral anticoagulation therapy who were already receiving this treatment at study entry had a trend towards a greater reduction in vascular events (relative risk 1.50, 95% CI 1.19-1.89) and a significantly (p=0.03 for interaction) lower risk of major bleeding with oral anticoagulation therapy (1.30; 0.94-1.79) than patients not on this treatment at study entry (1.27, 0.85-1.89 and 0.59, 0.32-1.08, respectively).

CONCLUSION

Oral anticoagulation therapy is superior to clopidogrel plus aspirin for prevention of vascular events in patients with atrial fibrillation at high risk of stroke, especially in those already taking oral anticoagulation therapy.

Rationale, design and baseline characteristics of a large, simple, randomized trial of combined folic acid and vitamins B6 and B12 in high-risk patients: the Heart Outcomes Prevention Evaluation (HOPE)-2 trial

BACKGROUND

Epidemiological studies suggest that mild to moderate elevation in plasma homocysteine concentration is associated with increased risk of atherothrombotic cardiovascular (CV) disease. Simple, inexpensive and nontoxic therapy with folic acid and vitamins B6 and B12 reduces plasma homocysteine levels by approximately 25% to 30% and may reduce CV events. Therefore, a large, randomized clinical trial--the Heart Outcomes Prevention Evaluation (HOPE)-2 study--is being conducted to evaluate this therapy in patients at high risk for CV events.

OBJECTIVES

To evaluate whether long-term therapy with folic acid and vitamins B6 and B12 reduces the risk of major CV events in a high-risk population. The primary study outcome is the composite of death from CV causes, myocardial infarction and stroke.

METHODS

A total of 5522 patients aged 55 years or older with pre-existing CV disease or with diabetes and additional risk factor(s) at 145 centres in 13 countries were randomly assigned to daily therapy with combined folic acid 2.5 mg, vitamin B6 50 mg and vitamin B12 1 mg, or to placebo. Follow-up will average five years, to be completed by the end of 2005.

RESULTS

The patients' baseline characteristics confirmed their high-risk status. Baseline homocysteine levels varied between countries and regions. HOPE-2 is one of the largest trials of folate and vitamins B6 and B12 and is expected to significantly contribute to the evaluation of the role of homocysteine lowering in CV prevention.

The relationship between dysglycaemia and cardiovascular and renal risk in diabetic and non-diabetic participants in the HOPE study: a prospective epidemiological analysis

AIMS/HYPOTHESIS

Emerging data suggest that different indices of glycaemia are risk factors for clinical events. The aim of this analysis was to investigate the relationship between fasting plasma glucose or glycated haemoglobin (GHb) levels and incident cardiovascular (CV) outcomes, death, heart failure and overt nephropathy in diabetic and non-diabetic individuals enrolled in the Heart Outcomes Prevention Evaluation (HOPE) study.

MATERIALS AND METHODS

The adjusted 4.5-year risk of CV events (myocardial infarction or stroke or CV death), heart failure, death and overt nephropathy was analysed in relation to baseline and updated GHb levels (in 3,529 diabetic HOPE study participants) and baseline fasting plasma glucose levels (in 1,937 non-diabetic and 1,013 diabetic participants).

RESULTS

In diabetic participants, a 1% absolute rise in the updated GHb predicted future CV events (relative risk [RR]=1.07, 95% CI 1.01-1.13; p=0.014), death (RR=1.12, 95% CI 1.05-1.19; p=0.0004), heart failure (RR=1.20, 95% CI 1.08-1.33; p=0.0008) and overt nephropathy (RR=1.26, 95% CI 1.17-1.36; p<0.0001) after adjusting for age, sex, diabetes duration, blood pressure, WHR, hyperlipidaemia and ramipril. Similarly, a 1 mmol/l rise in fasting plasma glucose was related to an increased risk of CV outcomes (RR=1.09, 95% CI 1.05-1.13; p<0.0001), death (RR=1.06, 95% CI 1.01-1.12; p=0.017), heart failure (RR=1.16, 95% CI 1.06-1.13; p=0.0007) and overt nephropathy (RR=1.34, 95% CI 1.23-1.45; p<0.0001) in the group composed of diabetic and non-diabetic individuals. The significant relationship between fasting plasma glucose and CV outcomes persisted after adjustment for diabetes status (RR=1.06, 95% CI 1.00-1.12; p=0.043).

CONCLUSIONS/INTERPRETATION

There is an independent progressive relationship between indices of glycaemia and incident CV events, renal disease and death. Clinical trials of glucose lowering to prevent these outcomes in diabetic and non-diabetic individuals are indicated.

Rationale, design and recruitment characteristics of a large, simple international trial of diabetes prevention: the DREAM trial

AIMS/HYPOTHESIS

Diabetes is a rapidly rising independent risk factor for atherosclerosis and serious illness. This risk can be reduced by lifestyle changes and/or various drugs. Novel therapies to prevent diabetes, as well as new risk factors for diabetes, atherosclerosis and obesity require testing and identification.

METHODS

People with impaired fasting glucose or impaired glucose tolerance were randomised to ramipril (15 mg/day) or placebo and rosiglitazone (8 mg/day) or placebo with a 2x2 factorial design. They are assessed semi-annually for the primary outcome (diabetes or death). Diabetes is diagnosed if two consecutive plasma glucose levels exceed diagnostic thresholds (i.e. fasting >/=7.0 mmol/l or 2-h >/=11.1 mmol/l) within a 3-month period. Assuming an annual primary outcome incidence of 5%, there is more than 90% power to detect a 22% reduction. Approximately 20% of participants are having annual carotid ultrasounds to assess the effects on atherosclerosis. Patients screened but not randomised are being followed prospectively to identify determinants of obesity, diabetes and related disorders.

RESULTS

A total of 24,872 individuals in 21 countries were screened over 2 years and are eligible for follow-up. Of these, 5269 were randomised: 1835 (35%) had isolated impaired glucose tolerance, 739 (14%) had isolated impaired fasting glucose, and 2692 (51%) had both disorders. Annual carotid ultrasounds are currently being performed in 1406 randomised individuals.

CONCLUSIONS/INTERPRETATION

The DREAM trial and related studies will determine if ramipril or rosiglitazone reduces the number of cases of diabetes and atherosclerosis, and will identify novel risk factors for diabetes.

Efficacy of hirudin in reducing cardiovascular events in patients with acute coronary syndrome undergoing early percutaneous coronary intervention

AIMS

Although hirudin is superior to unfractionated heparin for prevention of death, myocardial infarction, or refractory ischaemia in patients with non-ST-elevation acute coronary syndrome, it is not clear whether hirudin is also of benefit in acute coronary syndrome patients undergoing early percutaneous coronary intervention.

METHODS AND RESULTS

In the OASIS 2 trial, 10 141 patients with non-ST-elevation acute coronary syndrome were randomized to 72 h of intravenous hirudin or unfractionated heparin. Percutaneous coronary intervention was performed at the discretion of the investigator. One hundred and seventeen patients underwent percutaneous coronary intervention within the first 72 h ("early percutaneous coronary intervention"). In patients undergoing early percutaneous coronary intervention, hirudin compared with unfractionated heparin was associated with a significantly lower incidence of death or myocardial infarction at 96 h (6.4% vs 21.4%, OR 0.30; 95% CI: 0.10-0.88) and 35 days (6.4% vs 22.9%, OR 0.25; 95% CI: 0.07-0.86). In the unfractionated heparin group, death or myocardial infarction was significantly higher at 35 days in patients undergoing early percutaneous coronary intervention compared with those managed conservatively (22.9% vs 7.3%, OR 3.14, P<0.001) but this early percutaneous coronary intervention-related hazard was not observed in hirudin-treated patients (6.4% vs 6.8%, OR 0.94 P=1.0). A time-dependent covariate for percutaneous coronary intervention was not significant in a Cox regression model, suggesting a similar treatment benefit with hirudin before and after percutaneous coronary intervention. After adjustment for percutaneous coronary intervention propensity, the benefits of hirudin remained significant. There were three major bleeds in patients undergoing early percutaneous coronary intervention, all in patients randomized to hirudin.

CONCLUSION

In patients with non-ST-elevation acute coronary syndrome undergoing early percutaneous coronary intervention, a direct thrombin inhibitor such as hirudin may be more effective than heparin in reducing the incidence of ischaemic complications.

Blood-pressure reduction and cardiovascular risk in HOPE study

In the Heart Outcomes Prevention Evaluation (HOPE) study, use of the angiotensin-converting-enzyme inhibitor ramipril was associated with a 22% relative risk reduction in cardiovascular death, myocardial infarction, or stroke, despite only a modest reduction in blood pressure (23.3 mm Hg systolic). To test the hypothesis that the benefits seen were not due to reduced blood pressure alone, we calculated blood-pressure-related risk estimates from the placebo group of the HOPE trial, and from earlier studies. We found that the benefits seen in HOPE were around three times greater than predicted from these calculations. In this well treated and largely normotensive population with coronary disease, but good left-ventricular function, the benefits from ramipril were additive to other proven therapies in normotensive patients and in those with higher baseline blood pressure.

Ramipril and the development of diabetes

CONTEXT

Type 2 diabetes is a growing clinical and public health problem. Preventive efforts related to lifestyle modification are not always successful; therefore, alternative prevention strategies need to be studied.

OBJECTIVE

To investigate the effectiveness of ramipril, an angiotensin-converting enzyme inhibitor, in preventing diabetes among high-risk persons.

DESIGN, SETTING, AND PARTICIPANTS

The randomized, controlled Heart Outcomes Prevention Evaluation trial of 5720 patients older than 55 years without known diabetes but with vascular disease who were followed up for a mean of 4.5 years. The study included 267 hospitals in 19 countries and was conducted between 1994 and 1999.

INTERVENTION

Patients were randomly assigned to receive ramipril, up to 10 mg/d (n = 2837), or placebo (n = 2883).

MAIN OUTCOME MEASURE

Diagnosis of diabetes determined from self-report at follow-up visits every 6 months, compared between the 2 groups.

RESULTS

One hundred and two individuals (3.6%) in the ramipril group developed diabetes compared with 155 (5.4%) in the placebo group (relative risk [RR], 0.66; 95% confidence interval [CI], 0.51-0.85, P<.001). Similar results were noted when different diagnostic criteria were used; in the ramipril group, the RR for diagnosis of diabetes and hemoglobin A(1c) greater than 110% was 0.60 (95% CI, 0.43-0.85), for initiation of glucose-lowering therapy, 0.56 (95% CI, 0.41-0.77), and for both, 0.51 (95% CI, 0.34-0.76). These effects were also consistently seen in several subgroups examined.

CONCLUSIONS

Ramipril is associated with lower rates of new diagnosis of diabetes in high-risk individuals. Because these results have important clinical and public health implications, this hypothesis requires prospective confirmation.

Reduction of cardiovascular risk by regression of electrocardiographic markers of left ventricular hypertrophy by the angiotensin-converting enzyme inhibitor ramipril

BACKGROUND

Electrocardiographic markers of left ventricular hypertrophy (LVH) predict poor prognosis. We determined whether the ACE inhibitor ramipril prevents the development and causes regression of ECG-LVH and whether these changes are associated with improved prognosis independent of blood pressure reduction.

METHODS AND RESULTS

In the Heart Outcomes Prevention Evaluation (HOPE) study, patients at high risk were randomly assigned to ramipril or placebo and followed for 4.5years. ECGs were recorded at baseline and at study end. We compared prevention/regression and development/persistence of ECG-LVH in the two groups and related these changes to outcomes. At baseline, 676 patients had LVH (321 in the ramipril group and 355 in the placebo group) and 7605 patients did not have LVH (3814 in the ramipril group and 3791 in the placebo group). By study end, 336 patients in the ramipril group (8.1%) compared with 406 in the placebo group (9.8%) had development/persistence of LVH; in contrast, 3799 patients in the ramipril group (91.9%) compared with 3740 in the placebo group (90.2%) had regression/prevention of LVH (P=0.007). The effect of ramipril on LVH was independent of blood pressure changes. Patients who had regression/prevention of LVH had a lower risk of the predefined primary outcome (cardiovascular death, myocardial infarction, or stroke) compared with those who had development/persistence of LVH (12.3% versus 15.8%, P=0.006) and of congestive heart failure (9.3% versus 15.4%, P<0.0001).

CONCLUSIONS

The ACE inhibitor ramipril decreases the development and causes regression of ECG-LVH independent of blood pressure reduction, and these changes are associated with reduced risk of death, myocardial infarction, stroke, and congestive heart failure.

Stroke in relation to cardiac procedures in patients with non-ST-elevation acute coronary syndrome: a study involving >18 000 patients

BACKGROUND

There are few published data on risk factors for stroke in patients with non-ST-elevation acute coronary syndrome (ACS). We investigated prognostic factors for stroke in 2 large cohorts of patients from the Organization to Assess Strategies for Ischemic Syndromes (OASIS) registry (8010) and the OASIS-2 trial (10 141).

METHODS AND RESULTS

A total of 18 151 patients with non-ST-elevation ACS were enrolled in the OASIS program. Data from these 2 studies were pooled (a test for heterogeneity was nonsignificant, P=0.34). Overall, 238 patients (1.3%) had a stroke over a 6-month follow-up. Those who experienced stroke had a 4-fold increase in 6-month mortality (27.0% versus 6.3%, P<0.001). A Cox multivariate regression analysis identified CABG surgery as the most important predictor of stroke (hazard ratio [HR], 4.6), followed by history of stroke (HR, 2.3), diabetes mellitus (HR, 1.7), older age (HR, 1.6 per 10-year increase), higher heart rate (HR, 1.1 per 10-bpm increase), and on-site catheterization facility (HR, 1.4). There was no significant excess in stroke in patients undergoing percutaneous coronary intervention (P=0.21). Patients who underwent early CABG surgery were at a substantially increased risk compared with those who had later CABG (3.3% versus 1.6%; HR, 2.1; P=0.003) or who had no surgery (3.3% versus 1.1%; HR, 3.95; P=0.0001).

CONCLUSIONS

In this large cohort of patients with ACS, stroke was an uncommon but serious event associated with high mortality. The performance of early CABG surgery was a powerful independent predictor of stroke.

Renal insufficiency as a predictor of cardiovascular outcomes and the impact of ramipril: the HOPE randomized trial

BACKGROUND

The cardiovascular risk associated with early renal insufficiency is unknown. Clinicians are often reluctant to use angiotensin-converting enzyme inhibitors in patients with renal insufficiency.

OBJECTIVE

To determine whether mild renal insufficiency increases cardiovascular risk and whether ramipril decreases that risk.

DESIGN

Post hoc analysis.

SETTING

The Heart Outcomes and Prevention Evaluation (HOPE) study, a randomized, double-blind, multinational trial involving 267 study centers.

PATIENTS

980 patients with mild renal insufficiency (serum creatinine concentration >/= 124 micromol/L [>/=1.4 mg/dL]) and 8307 patients with normal renal function (serum creatinine concentration < 124 micromol/L [<1.4 mg/dL]) Patients with a baseline serum creatinine concentration greater than 200 micromol/L (2.3 mg/dL) were excluded.

MEASUREMENTS

The primary outcome measure was incidence of cardiovascular death, myocardial infarction, or stroke.

RESULTS

Cumulative incidence of the primary outcome was higher in patients with renal insufficiency than in those without (22.2% vs. 15.1%; P < 0.001) and increased with serum creatinine concentration. Patients with renal insufficiency had a substantially increased risk for cardiovascular death (11.4% vs. 6.6%) and total mortality (17.8% vs. 10.6%) (P < 0.001 for both comparisons). The effect of renal insufficiency on the primary outcome (adjusted hazard ratio, 1.40 [95% CI, 1.16 to 1.69]) was independent of known cardiovascular risks and treatment. Ramipril reduced the incidence of the primary outcome in patients with and those without renal insufficiency (hazard ratio, 0.80 vs. 0.79; P > 0.2 for the difference).

CONCLUSIONS

In patients who had preexisting vascular disease or diabetes combined with an additional cardiovascular risk factor, mild renal insufficiency significantly increased the risk for subsequent cardiovascular events. Ramipril reduced cardiovascular risk without increasing adverse effects.

Safety outcomes in meta-analyses of phase 2 vs phase 3 randomized trials: Intracranial hemorrhage in trials of bolus thrombolytic therapy

CONTEXT

Recent studies have reported disagreement between meta-analysis of small trials and subsequent large trials addressing the same question. However, disagreement for uncommon but serious adverse safety outcomes has not been examined.

OBJECTIVE

To explore disagreement for serious adverse safety (intracranial hemorrhage [ICH]) and efficacy outcomes between meta-analysis of phase 2 (small) vs meta-analysis of phase 3 (large) randomized controlled trials comparing the efficacy of bolus thrombolytic therapy with infusion for acute myocardial infarction (AMI).

DATA SOURCES

Electronic databases (MEDLINE, Cochrane Database of Clinical Trials) between January 1980 and December 1999 using the search terms thrombolysis, thrombolytic therapy, and myocardial infarction; conference proceedings; and reference lists.

STUDY SELECTION

Fifteen randomized trials comparing thrombolytic agents administered by bolus injection with standard infusion therapy in patients with AMI.

DATA EXTRACTION

Data on ICH, other causes of stroke, total mortality, and reinfarction were independently extracted from each study by 2 observers.

DATA SYNTHESIS

Meta-analysis of 9 phase 2 trials (n = 3956) revealed a lower risk of ICH with bolus thrombolytic therapy (odds ratio [OR], 0.53; 95% confidence interval [CI], 0.27-1.01), which was not statistically significant. Meta-analysis of 6 phase 3 trials (n = 62 673) indicated a significant increase in risk of ICH (OR, 1.25; 95% CI, 1.06-1.49). These results were significantly different (P =.01). There was no disagreement for efficacy outcomes. Phase 2 trials included younger and heavier patients with lower baseline blood pressures, and were more often open-label. Subgroup analyses suggested that each of these factors was associated with a lower estimate of risk of ICH with bolus agents.

CONCLUSIONS

Our results suggest that when therapeutic interventions are associated with a potential for uncommon but serious adverse safety outcomes, there may be differences between small phase 2 and large phase 3 trials that result in their disagreement for safety but not necessarily efficacy outcomes. Further investigation of the frequency and causes of disagreement between small and large trials for safety outcomes is warranted.

Functional capacity in patients with congestive heart failure

BACKGROUND

Six-minute walk distance (6MWd) is related to activities of daily living and is also an independent predictor of prognosis in patients with congestive heart failure (CHF). Therefore, it is important to determine factors that contribute to the variability of this test.

METHODS AND RESULTS

We assessed the relationship between 6MWd and peak aerobic capacity (VO2) and dynamic muscle strength in 180 patients with CHF (age, 66+/-10 years; 146 men, 34 women; ejection fraction, .29+/-0.08). We also hypothesized that a measure of work performed during the walk test (6MWw) would be a better indicator of exercise capacity than 6MWd. The 6MWd had weak to moderate correlations with dynamic muscle strength (r = 0.33 to 0.41) and peak VO2 (r = 0.48). However, 6MWw was strongly related to dynamic muscle strength (r = 0.63 to 0.70) and peak VO2 (r = 0.77). Multivariate analysis indicated that a model combining dynamic muscle strength and peak VO2 explained 69% of the variance in 6MWw, more than with peak VO2 alone (R2 = 0.59).

CONCLUSIONS

Compared with 6MWd, 6MWw correlates significantly better with peak VO2 and dynamic muscle strength, suggesting that 6MWw may be a better reflection of a patient's exercise capacity. Furthermore, these results suggest that an exercise program combining both aerobic and strength training in patients with CHF may improve 6MWw and therefore 6MWd.

Reactivation of coagulation after stopping infusions of recombinant hirudin and unfractionated heparin in unstable angina and myocardial infarction without ST elevation: results of a randomized trial. OASIS Pilot Study Investigators. Organization to Assess Strategies for Ischemic++ Syndromes

AIMS

To compare effects of heparin and hirudin on biochemical markers of coagulation.

METHODS AND RESULTS

Patients (n=395) with unstable angina or myocardial infarction without ST elevation were randomized to a 72-h infusion of one of three regimens: unfractionated heparin (bolus of 5000 IU followed by an infusion of 1200 IU. h(-1)), low-dose hirudin (HBW 023; 0.2 mg. kg(-1)bolus followed by 0.10 mg. kg(-1). h(-1)) or medium-dose hirudin (0.4 mg. kg(-1)bolus followed by 0.15 mg. kg(-1). h(-1)). Infusions were adjusted to maintain an activated partial thromboplastin time of between 60-100 s. Activated partial thromboplastin time, prothrombin fragment 1.2 (F1.2), thrombin antithrombin III complex and D-dimer were measured before, during and after the infusion. Median activated partial thromboplastin time was similar in the two groups early on, but was significantly lower in the heparin group than in the combined hirudin group 48 h after starting the infusion (53 s and 75 s, respectively;P<0.001), and 6 h after stopping (31 s and 46 s, respectively;P<0.001). Median F1.2 levels were not significantly different between the groups during the infusion. Median thrombin antithrombin III levels in the heparin and hirudin groups were 2.8 microg. l(-1)and 2.3 microg. l(-1), respectively, at 6 h (P<0.001), and 3.0 microg. l(-1)and 2.3 microg. l(-1), respectively, at 48 h (P<0.001). Median D-dimer levels were 320 ng. ml(-1)and 260 ng. ml(-1)48 h after starting the infusion in the heparin and hirudin groups, respectively (P<0.001), and 415 ng. ml(-1)and 280 ng. ml(-1), respectively (P<0.001) 6 h after stopping. D-dimer levels were significantly elevated above baseline values in both groups 24-48 h after stopping the infusions.

CONCLUSIONS

The greater reduction of thrombin antithrombin III and D-dimer during the hirudin infusion supports the hypothesis that hirudin is a more potent antithrombin agent than heparin. Increased D-dimer levels after stopping heparin or hirudin suggest that there is an ongoing pro-coagulant state. These results point to the greater efficacy of hirudin in preventing early clinical events (death, myocardial infarction and refractory ischaemia) compared with heparin that have been observed in large randomized trials. Persistent activation of coagulation afterstopping infusions in our study suggests that a longer course of antithrombotic treatment may be needed to pacify the thrombus.

Long-term ACE-inhibitor therapy in patients with heart failure or left-ventricular dysfunction: a systematic overview of data from individual patients. ACE-Inhibitor Myocardial Infarction Collaborative Group

BACKGROUND

We undertook a prospective systematic overview based on data from individual patients from five long-term randomised trials that assessed inhibitors of angiotensin-converting enzyme (ACE) in patients with left-ventricular dysfunction or heart failure.

METHODS

Three of the trials enrolled patients within a week after acute myocardial infarction. Data were combined by use of the Peto-Yusuf method.

FINDINGS

Overall 12,763 patients were randomly assigned treatment or placebo and followed up for an average of 35 months. In the three post-infarction trials (n=5,966), mortality was lower with ACE inhibitors than with placebo (702/2995 [23.4%] vs 866/2971 [29.1%]; odds ratio 0.74 [95% CI 0.66-0-83]), as were the rates of readmission for heart failure (355 [11.9%] vs 460 [15.5%]; 0.73 [0.63-0.85]), reinfarction (324 [10.8%] vs 391 [13.2%]; 0.80 [0.69-0.94]), or the composite of these events (1049 [35.0%] vs 1244 [41.9%]; 0.75 [0.67-0.83]; all p<O.001). For all five trials the ACE inhibitor group had lower rates of death than the placebo group (1,467/6,391 [23.0%] vs 1,710/6,372 [26.8%]; 0.80 [0.74-0.87]) and lower rates of reinfarction (571 [8.9%] vs 703 [11.0%]; 0.79 [0.70-0.89]), readmission for heart failure (876 [13.7%] vs 1202 [18.9%]; 0.67 [0.61-0.74]), and the composite of these events (2161 [33.8%] vs 2610 [41.0%]; 0.72 [0.67-0.78]; all p<0.0001). The benefits were observed early after the start of therapy and persisted long term. The benefits of treatment on all outcomes were independent of age, sex, and baseline use of diuretics, aspirin, and beta-blockers. Although there was a trend towards greater reduction in risk of death or readmission for heart failure in patients with lower ejection fractions, benefit was apparent over the range examined.

Prevalence and determinants of microalbuminuria in high-risk diabetic and nondiabetic patients in the Heart Outcomes Prevention Evaluation Study. The HOPE Study Investigators

OBJECTIVE

To describe the characteristics of diabetic and nondiabetic participants in the Heart Outcomes Prevention Evaluation (HOPE) Study who are at high risk of developing cardiovascular (CV) disease and who have microalbuminuria (MA), and to identify the key determinants of MA in these two groups.

RESEARCH DESIGN AND METHODS

Albuminuria was measured in 97% of patients enrolled in the HOPE Study as part of the MICRO-HOPE (MA, CV, and Renal Outcomes in HOPE) substudy. Baseline clinical characteristics of diabetic and nondiabetic participants with MA were recorded, and the univariate and multivariate relationship between these characteristics and the presence of MA was estimated for both groups.

RESULTS

Baseline urinary albumin determinations were available in 3,574 (97.8%) diabetic participants and 5,708 (97.0%) nondiabetic participants. MA was detected in 1,151 (32.2%) diabetic participants and 837 (14.7%) nondiabetic participants. Age, waist-to-hip ratio, diabetes, smoking, hypertension, vascular disease, and left ventricular hypertrophy were independent determinants of MA in all participants. In diabetic participants, the odds of MA increased 16% for every 10.4 years of diabetes duration, and increased 8% for every 0.9% increase in glycated hemoglobin (assuming a GHb assay with an upper limit of 6% in the nondiabetic range).

CONCLUSIONS

MA is independently associated with several risk factors for CV and renal disease in both diabetic and nondiabetic individuals at high risk for CV disease.

Vitamin E supplementation and cardiovascular events in high-risk patients

BACKGROUND

Observational and experimental studies suggest that the amount of vitamin E ingested in food and in supplements is associated with a lower risk of coronary heart disease and atherosclerosis.

METHODS

We enrolled a total of 2545 women and 6996 men 55 years of age or older who were at high risk for cardiovascular events because they had cardiovascular disease or diabetes in addition to one other risk factor. These patients were randomly assigned according to a two-by-two factorial design to receive either 400 IU of vitamin E daily from natural sources or matching placebo and either an angiotensin-converting-enzyme inhibitor (ramipril) or matching placebo for a mean of 4.5 years (the results of the comparison of ramipril and placebo are reported in a companion article). The primary outcome was a composite of myocardial infarction, stroke, and death from cardiovascular causes. The secondary outcomes included unstable angina, congestive heart failure, revascularization or amputation, death from any cause, complications of diabetes, and cancer.

RESULTS

A total of 772 of the 4761 patients assigned to vitamin E (16.2 percent) and 739 of the 4780 assigned to placebo (15.5 percent) had a primary outcome event (relative risk, 1.05; 95 percent confidence interval, 0.95 to 1.16; P=0.33). There were no significant differences in the numbers of deaths from cardiovascular causes (342 of those assigned to vitamin E vs. 328 of those assigned to placebo; relative risk, 1.05; 95 percent confidence interval, 0.90 to 1.22), myocardial infarction (532 vs. 524; relative risk, 1.02; 95 percent confidence interval, 0.90 to 1.15), or stroke (209 vs. 180; relative risk, 1.17; 95 percent confidence interval, 0.95 to 1.42). There were also no significant differences in the incidence of secondary cardiovascular outcomes or in death from any cause. There were no significant adverse effects of vitamin E.

CONCLUSIONS

In patients at high risk for cardiovascular events, treatment with vitamin E for a mean of 4.5 years had no apparent effect on cardiovascular outcomes.

Effects of an angiotensin-converting-enzyme inhibitor, ramipril, on cardiovascular events in high-risk patients

BACKGROUND

Angiotensin-converting-enzyme inhibitors improve the outcome among patients with left ventricular dysfunction, whether or not they have heart failure. We assessed the role of an angiotensin-converting-enzyme inhibitor, ramipril, in patients who were at high risk for cardiovascular events but who did not have left ventricular dysfunction or heart failure.

METHODS

A total of 9297 high-risk patients (55 years of age or older) who had evidence of vascular disease or diabetes plus one other cardiovascular risk factor and who were not known to have a low ejection fraction or heart failure were randomly assigned to receive ramipril (10 mg once per day orally) or matching placebo for a mean of five years. The primary outcome was a composite of myocardial infarction, stroke, or death from cardiovascular causes. The trial was a two-by-two factorial study evaluating both ramipril and vitamin E. The effects of vitamin E are reported in a companion paper.

RESULTS

A total of 651 patients who were assigned to receive ramipril (14.0 percent) reached the primary end point, as compared with 826 patients who were assigned to receive placebo (17.8 percent) (relative risk, 0.78; 95 percent confidence interval, 0.70 to 0.86; P<0.001). Treatment with ramipril reduced the rates of death from cardiovascular causes (6.1 percent, as compared with 8.1 percent in the placebo group; relative risk, 0.74; P<0.001), myocardial infarction (9.9 percent vs. 12.3 percent; relative risk, 0.80; P<0.001), stroke (3.4 percent vs. 4.9 percent; relative risk, 0.68; P<0.001), death from any cause (10.4 percent vs. 12.2 percent; relative risk, 0.84; P=0.005), revascularization procedures (16.3 percent vs. 18.8 percent; relative risk, 0.85; P<0.001), cardiac arrest (0.8 percent vs. 1.3 percent; relative risk, 0.62; P=0.02), [corrected] heart failure (9.1 percent vs. 11.6 percent; relative risk, 0.77; P<0.001), and complications related to diabetes (6.4 percent vs. 7.6 percent; relative risk, 0.84; P=0.03).

CONCLUSIONS

Ramipril significantly reduces the rates of death, myocardial infarction, and stroke in a broad range of high-risk patients who are not known to have a low ejection fraction or heart failure.

Comparison of candesartan, enalapril, and their combination in congestive heart failure: randomized evaluation of strategies for left ventricular dysfunction (RESOLVD) pilot study. The RESOLVD Pilot Study Investigators

BACKGROUND

We investigated the effects of candesartan (an angiotensin II antagonist) alone, enalapril alone, and their combination on exercise tolerance, ventricular function, quality of life (QOL), neurohormone levels, and tolerability in congestive heart failure (CHF).

METHODS AND RESULTS

Seven hundred sixty-eight patients in New York Heart Association functional class (NYHA-FC) II to IV with ejection fraction (EF) <0.40 and a 6-minute walk distance (6MWD) <500 m received either candesartan (4, 8, or 16 mg), candesartan (4 or 8 mg) plus 20 mg of enalapril, or 20 mg of enalapril for 43 weeks. There were no differences among groups with regard to 6MWD, NYHA-FC, or QOL. EF increased (P=NS) more with candesartan-plus-enalapril therapy (0.025+/-0.004) than with candesartan alone (0.015+/-0.004) or enalapril alone(0.015+/-0.005). End-diastolic (EDV) and end-systolic (ESV) volumes increased less with combination therapy (EDV 8+/-4 mL; ESV 1+/-4 mL; P<0.01) than with candesartan alone (EDV 27+/-4 mL; ESV 18+/-3 mL) or enalapril alone (EDV 23+/-7 mL; ESV 14+/-6 mL). Blood pressure decreased with combination therapy (6+/-1/4+/-1 mm Hg) compared with candesartan or enalapril alone (P<0.05). Aldosterone decreased (P<0.05) with combination therapy (23.2+/-5.3 pg/mL) at 17 but not 43 weeks compared with candesartan (0.7+/-7.8 pg/mL) or enalapril (-0.8+/-11. 3 pg/mL). Brain natriuretic peptide decreased with combination therapy (5.8+/-2.7 pmol/L; P<0.01) compared with candesartan (4. 4+/-3.8 pmol/L) and enalapril alone (4.0+/-5.0 pmol/L).

CONCLUSIONS

Candesartan alone was as effective, safe, and tolerable as enalapril. The combination of candesartan and enalapril was more beneficial for preventing left ventricular remodeling than either candesartan or enalapril alone.

The Organization to Assess Strategies for Ischemic Syndromes (OASIS) registry in patients with unstable angina

Clinical approaches to the prevention of the potentially catastrophic consequences of coronary ischemic phenomena such as unstable angina and suspected non-Q-wave myocardial infarction (MI) differ across the world. In addition to prevailing physician beliefs in different societies, the level of access to catheterization laboratories largely determines whether an interventionist or conservative strategy is adopted. The Organization to Assess Strategies for Ischemic Syndromes (OASIS)--a prospective registry of approximately 8,000 patients with acute myocardial ischemia with no ST elevation, treated in 95 hospitals across 6 countries--furnished a unique window into regional differences in clinical management and the frequency and timing of invasive procedures (i.e., angiography, percutaneous transluminal coronary angioplasty [PTCA], and coronary artery bypass graft [CABG] surgery), as well as the outcomes of these trends. At 6 months after symptom onset, patients in the United States and Brazil, where the catheterization laboratory facilities are more accessible, underwent significantly (p <0.001) more angiography (69.4%), PTCA (23.6%), and CABG (25.2%) than in Canada and Australia, where the corresponding rates were 48.4%, 17.0%, and 16.8% (p <0.001), respectively; and in Hungary and Poland, where the respective rates were 23.5%, 5.8%, and 10.9% (p <0.001). This relatively aggressive approach led at 6 months to a more substantial decrease in refractory angina in the United States and Brazil than in Canada and Australia (20.4% vs 13.9%; p <0.001), but no improvement in rates of cardiovascular mortality and MI (10.5% versus 10.5%; p = 0.36). There was a significant (p < or = 0.012) increase in stroke, (1.9% vs 1.3%; p = 0.010) and major bleeding (1.9% vs 1.1%; p = 0.009) events. Furthermore, an inverse correlation emerged between baseline cardiovascular risk status and frequency of angiography and PTCA interventions preferentially for low-risk compared with high-risk patients. In concert with findings from other recent randomized trials, the OASIS Registry data suggest that although there are fewer hospital readmissions for unstable angina, there is a trend toward increased rates of death, MI, and stroke. These data urge a cautious approach to the use of invasive procedures in patients with unstable angina unless future trials demonstrate a clear benefit with an aggressive approach.

Relationship of glucose and insulin levels to the risk of myocardial infarction: a case-control study

OBJECTIVE

To assess the relationship between dysglycemia and myocardial infarction in nondiabetic individuals.

BACKGROUND

Nondiabetic hyperglycemia may be an important cardiac risk factor. The relationship between myocardial infarction and glucose, insulin, abdominal obesity, lipids and hypertension was therefore studied in South Asians-a group at high risk for coronary heart disease and diabetes.

METHODS

Demographics, waist/hip ratio, fasting blood glucose (FBG), insulin, lipids and glucose tolerance were measured in 300 consecutive patients with a first myocardial infarction and 300 matched controls.

RESULTS

Cases were more likely to have diabetes (OR 5.49; 95% CI 3.34, 9.01), impaired glucose tolerance (OR 4.08; 95% CI 2.31, 7.20) or impaired fasting glucose (OR 3.22; 95% CI 1.51, 6.85) than controls. Cases were 3.4 (95% CI 1.9, 5.8) and 6.0 (95% CI 3.3, 10.9) times more likely to have an FBG in the third and fourth quartile (5.2-6.3 and >6.3 mmol/1); after removing subjects with diabetes, impaired glucose tolerance and impaired fasting glucose, cases were 2.7 times (95% CI 1.5-4.8) more likely to have an FBG >5.2 mmol/l. A fasting glucose of 4.9 mmol/l best distinguished cases from controls (OR 3.42; 95% CI 2.42, 4.83). Glucose, abdominal obesity, lipids, hypertension and smoking were independent multivariate risk factors for myocardial infarction. In subjects without glucose intolerance, a 1.2 mmol/l (21 mg/dl) increase in postprandial glucose was independently associated with an increase in the odds of a myocardial infarction of 1.58 (95% CI 1.18, 2.12).

CONCLUSIONS

A moderately elevated glucose level is a continuous risk factor for MI in nondiabetic South Asians with either normal or impaired glucose tolerance.

Long-term oral anticoagulant therapy in patients with unstable angina or suspected non-Q-wave myocardial infarction: organization to assess strategies for ischemic syndromes (OASIS) pilot study results

BACKGROUND

Patients with acute ischemic syndromes (AIS) suffer high rates of recurrent ischemic events despite aspirin treatment. Long-term therapy with oral anticoagulants in addition to aspirin may reduce this risk. We studied the effects of long-term warfarin at 2 intensities in patients with AIS without ST elevation in 2 consecutive randomized controlled studies.

METHODS AND RESULTS

In phase 1, after the cessation of 3 days of intravenous antithrombotic therapy, 309 patients were randomized to receive fixed low-dose (3 mg/d) warfarin for 6 months that produced a mean international normalized ratio (INR) of 1.5+/-0.6 or to standard therapy. Eighty-seven percent of patients received aspirin in both groups. The rates of cardiovascular (CV) death, new myocardial infarction (MI), and refractory angina at 6 months were 6.5% in the warfarin group and 3.9% in the standard therapy group (relative risk [RR], 1. 66; 95% CI, 0.62 to 4.44; P=0.31). The rates of death, new MI, and stroke were 6.5% in the warfarin group and 2.6% in the standard therapy group (RR, 2.48; 95% CI, 0.80 to 7.75; P=0.10). The overall rate of rehospitalization for unstable angina was 21% and did not differ significantly between the groups. Four patients in the warfarin group (2.6%) and none in the control group experienced a major bleed (RR, 2.48; 95% CI, 0.80 to 7.75), and there was a significant excess of minor bleeds in the warfarin group (14.2% versus 2.6%; RR, 5.46; 95% CI, 1.93 to 15.5; P=0.001). In phase 2, the protocol was modified, and 197 patients were randomized <48 hours from the onset of symptoms to receive warfarin at an adjusted dose that produced a mean INR of 2.3+/-0.6 or standard therapy for 3 months. Eighty-five percent received aspirin in both groups. The rates of CV death, new MI, and refractory angina at 3 months were 5. 1% in the warfarin group and 12.1% in the standard group (RR, 0.42; 95% CI, 0.15 to 1.15; P=0.08). The rates of all death, new MI, and stroke were 5.1% in the warfarin group and 13.1% in the standard therapy group (RR, 0.39; 95% CI, 0.14 to 1.05; P=0.05). Significantly fewer patients were rehospitalized for unstable angina in the warfarin group than in the control group (7.1% and 17.2%, respectively; RR, 0.42; 95% CI, 0.18 to 0.96; P=0.03). Two patients in the warfarin group and 1 in the control group experienced a major bleed, and there was a significant excess of minor bleeds in the warfarin group (28.6% versus 12.1%; RR, 2.36; 95% CI, 1.37 to 4.36; P=0.004).

CONCLUSIONS

Long-term treatment with moderate-intensity warfarin (INR, 2.0 to 2.5) plus aspirin but not low-intensity warfarin (INR, 1.5) plus aspirin appears to reduce the rate of recurrent ischemic events in patients with AIS without ST elevation.

Variations between countries in invasive cardiac procedures and outcomes in patients with suspected unstable angina or myocardial infarction without initial ST elevation. OASIS (Organisation to Assess Strategies for Ischaemic Syndromes) Registry Investigators

BACKGROUND

There are wide variations between countries in the use of invasive cardiac catheterisation and revascularisation procedures for patients with acute ischaemic syndromes. We studied the relation between rates of such procedures and rates of cardiovascular death, myocardial infarction, stroke, refractory angina, and major bleeding in a prospective, registry-based study in six countries with widely varying intervention rates.

METHODS

7987 consecutive patients presenting with unstable angina or suspected myocardial infarction without ST-segment elevation were recruited prospectively from 95 hospitals in six countries and followed up for 6 months.

FINDINGS

The rates of all procedures were highest in patients in Brazil and the USA, intermediate in Canada and Australia, and lowest in Hungary and Poland. There were no significant differences in rates of cardiovascular death or myocardial infarction among these countries (4.7% overall [range 3.7-5.6] at 7 days; 11% overall [9-12] at 6 months). For the countries with the highest rates of invasive procedures (59%) versus the rest (21%) there was no difference in rate of cardiovascular death or myocardial infarction (adjusted odds ratio 0.88 at 7 days and 1.0 at 6 months). Rates of stroke were higher in Brazil and the USA than in the countries with lower intervention rates (adjusted odds ratio at 7 days 3.0, p=0.012; at 6 months 1.8, p=0.004) but rates of refractory angina at 7 days (0.7, p<0.001) and readmission for unstable angina at 6 months were lower (0.70, 0.63; both p<0.001). Comparison of results for hospitals without cardiac-catheterisation facilities and for those with such facilities gave adjusted odds ratios for cardiovascular death, myocardial infarction, or stroke at 6 months of 0.83 (10.6% vs 12.5%, p=0.05) and for refractory angina of 1.25 (19.3% vs 16.1%, p=0.09).

INTERPRETATION

Higher rates of invasive and revascularisation procedures were associated with lower rates of refractory angina or readmission for unstable angina, no apparent reduction in cardiovascular death or myocardial infarction, but with higher rates of stroke. Randomised trials should assess the relative impact of conservative and more aggressive approaches to invasive cardiac procedures and revascularisations in patients with unstable angina.

Beta-blocker therapy for congestive heart failure: a systemic overview and critical appraisal of the published trials

OBJECTIVE

To evaluate the effect of beta-blockers on mortality and morbidity, and to provide an appraisal of the reliability of the available data.

DATA SOURCES

MEDLINE search for trials of beta-blockers for congestive heart failure (CHF).

STUDY SELECTION

All randomized trials of beta-blockers versus placebo, or greater than one month's duration, in patients with CHF. Eighteen published trials involving 2986 patients were selected.

DATA EXTRACTION

Independently by two authors.

DATA SYNTHESIS

The Yusuf-Peto method for combining data was used. Data were available on mortality in 2841 patients (95%), on hospitalization for heart failure in 1514 (51%) and on heart transplantation in 2330 (79%). There was a lower rate of death in the active treatment group (131 of 1606) [8.2] versus 155 of 1235 [12.6%]; OR = 72; 99% CI 0.51 to 1.00), a lower rate of hospitalization for heart failure (137 of 756 [18.1%] versus 218 of 758 [28.7%]; OR = 0.54; 99% CI 0.39 to 0.74) and a trend towards a lower proportion of patients receiving heart transplantation (15 of 1354 [l.1%] versus 26 of 976 [2.7%]; OR = 0.45; 99% CI 0.20 to 1.03). Ventricular function improved; however, there was no effect on exercise duration. Although the effects on mortality were nominally statistically significant, the use of formal methods of interim monitoring adapted for meta-analyses suggests that substantially more patients still need to be studied in large scales trials to provide reliable and conclusive evidence.

CONCLUSIONS

While the available data on the use of beta-blockers in CHF appear to be promising, they are neither complete nor robust. The routine use of beta-blockers in patients with heart failure should wait the results of ongoing studies.

Elevated lipoprotein(a) levels in South Asians in North America

This report demonstrates that South Asians living in North America have elevated levels of Lp(a) compared with North American whites. Elevated Lp(a) levels may account, in part, for the tendency of South Asians to develop premature coronary heart disease (CHD).

Overcoming the limitations of current meta-analysis of randomised controlled trials

For a meta-analysis to give definitive information, it should meet at least the minimum standards that would be expected of a well-designed, adequately powered, and carefully conducted randomised controlled trial. These minimum standards include both qualitative characteristics--a prospective protocol, comparable definitions of key outcomes, quality control of data, and inclusion of all patients from all trials in the final analysis--and quantitative standards--an assessment of whether the total sample is large enough to provide reliable results and the use of appropriate statistical monitoring guidelines to indicate when the results of the accumulating data of a meta-analysis are conclusive. We believe that rigorous meta-analyses undertaken according to these principles will lead to more reliable evidence about the efficacy and safety of interventions than either retrospective meta-analysis or individual trials.

Combination neurohormonal blockade with ACE inhibitors, angiotensin II antagonists and beta-blockers in patients with congestive heart failure: design of the Randomized Evaluation of Strategies for Left Ventricular Dysfunction (RESOLVD) Pilot Study

BACKGROUND

The Randomized Evaluation of Strategies for Left Ventricular Dysfunction (RESOLVD) Pilot Study is a trial of combination neurohormonal blockade using an angiotensin II antagonist (candesartan), an angiotensin-converting enzyme inhibitor (enalapril) and a beta-blocker (metoprolol) in patients with congestive heart failure (CHF).

OBJECTIVES

Primary objectives of stage I are to determine the efficacy (via the 6 min walk test) and safety of candesartan alone, and in combination with enalapril, versus enalapril alone. Secondary objectives are to determine the effect of the above combinations on neurohormones, ventricular function, quality of life and symptoms. Stage II objectives are similar, evaluating the effect of the addition of metoprolol or placebo to the above medication(s).

DESIGN

Randomized, two-stage trial consisting of a three-way comparison (stage I), followed by a 3 x 2 partial factorial design (stage II).

SETTING

Sixty out-patient clinics in five countries.

PATIENTS

Patients with symptoms of CHF (New York Heart Association functional classes II to IV), ejection fraction less than 40% and 6 min walk distance of 500 m or less.

INTERVENTIONS

In stage I, 770 patients are randomized to receive candesartan alone, enalapril alone, or candesartan plus enalapril. After five months (end of stage I), patients are assessed for eligibility to be randomized in stage II. Those who are not candidates for randomization to beta-blocker or placebo are followed on their stage I medications until the end of the study. In stage II, patients are randomized to receive metoprolol or placebo for a further six months in addition to their stage I medications. Endpoints are measured at baseline, end of stage I (week 20) and end of stage II (week 46). STUDY STATUS: The study has recently completed follow-up in both stages. The findings from this study will be used to design a large scale mortality study that will help further define the role of neurohormonal blockade in patients with CHF.

A comparison of practice patterns for acute myocardial infarction between hospitals in Canada and India

The increasing burden of cardiovascular disease in India, and the established efficacy of mortality-reducing therapies in acute myocardial infarction (AMI) served as the impetus to compare the management practices of AMI in an Indian hospital and a similar hospital in Canada. A retrospective chart review in each hospital was conducted to identify differences in risk factors, presentation, and acute in-hospital management in patients with AMI. Indian patients were younger (47 +/- 9 years versus 54 +/- 8 years), more likely to have a history of diabetes (21/87 versus 6/69) and less likely to have a previous history of angina (5/87 versus 22/69) compared to Canadian patients (all p < 0.001). The delay from symptom onset to hospital arrival was greater in Bangalore, India (median time 330 min versus 101 min, p < 0.001), yet the in-hospital delay in receiving thrombolytic therapy was greater in Hamilton, Canada (70.5 min in Hamilton versus 30 min in Bangalore, p < 0.0001). There was similarity and appropriate use of thrombolytic therapy, aspirin, beta-blockers and angiotensin-converting enzyme (ACE) inhibitors in both centres. The pattern of presentation and risk factors differ in Indian and Canadian patients. However, once patients present, the patterns of practice appear to be similar.

Rationale and design of a large study to evaluate the renal and cardiovascular effects of an ACE inhibitor and vitamin E in high-risk patients with diabetes. The MICRO-HOPE Study. Microalbuminuria, cardiovascular, and renal outcomes. Heart Outcomes Prevention Evaluation

OBJECTIVE

To describe the rationale and design of a large international study (microalbuminuria, cardiovascular, and renal outcomes [MICRO] in the HOPE [Heart Outcomes Prevention Evaluation] study) of an ACE inhibitor and vitamin E for the prevention of diabetic nephropathy (DN) and cardiovascular disease (CVD) in patients with diabetes and microalbuminuria (MA).

RESEARCH DESIGN AND METHODS

A total of 3,657 diabetic subjects, including 1,129 with MA, are randomly allocated to receive the ACE inhibitor ramipril (or placebo) and vitamin E (or placebo) for 4 years in a two-by-two factorial design. Diabetic subjects are a subset of the 9,541 subjects enrolled in the HOPE study.

RESULTS

The development of DN in microalbuminuric diabetic subjects and the development of MA in normoalbuminuric subjects, as well as cardiovascular death, myocardial infarction, and storke, are the main outcomes. The correlation of changes in albuminuria with changes in carotid atherosclerosis documented in a subset of subjects will also be analyzed.

CONCLUSIONS

The effect of both an ACE inhibitor and vitamin E on the progression of renal and CVD in patients with diabetes is being assessed in the MICRO-HOPE study.

Study design and baseline characteristics of the study to evaluate carotid ultrasound changes in patients treated with ramipril and vitamin E: SECURE

Atherosclerotic cardiovascular disease remains a major cause of mortality and morbidity in most developed countries. Experimental and clinical evidence suggests that angiotensin-converting enzyme inhibitors and vitamin E therapy may retard the atherosclerotic process; however, definitive proof in humans is lacking. The Study to Evaluate Carotid Ultrasound Changes in Patients Treated with Ramipril and Vitamin E (SECURE) is designed to assess the effects of ramipril--an angiotensin-converting enzyme inhibitor, at 2 doses: 2.5 mg daily (which has little effect on lowering blood pressure) and 10 mg daily--and the antioxidant vitamin E, 400 IU daily, on atherosclerosis progression in 732 patients using a factorial 3 x 2 study design. High-risk patients with a documented history of significant cardiovascular disease or with diabetes and additional risk factors were enrolled and will be followed for 4 years. The extent and progression of atherosclerosis are assessed noninvasively by B-mode carotid ultrasonography. The SECURE trial is a substudy of the larger Heart Outcomes Prevention Evaluation (HOPE) study of 9,541 high-risk patients evaluating the effects of ramipril and vitamin E on major cardiovascular events (cardiovascular death, myocardial infarction, and stroke). The 2 studies are complementary. Whereas HOPE is expected to provide information on major clinical outcomes, SECURE will shed light on the mechanisms by which these effects may be mediated.

Risk factors for acute myocardial infarction in Indians: a case-control study

BACKGROUND

South Asians who have settled overseas and those in urban India have an increased risk of ischaemic heart disease (IHD). Reasons for this increased risk are unclear. Most studies have been based on migrants to western nations, so their findings may not apply to most south Asians, who live in their own countries. Therefore, we assessed the relative importance of risk factors for IHD among South Asians in Bangalore, India.

METHODS

We conducted a prospective hospital-based case-control study of 200 Indian patients with a first acute myocardial infarction (AMI) and 200 age and sex matched controls. We recorded prevalence of the following risk factors for IHD: diet, smoking, alcohol use, socioeconomic status, waist to hip ratio (WHR), blood glucose, serum insulin, oral glucose tolerance test, and lipid profile.

FINDINGS

The most important predictor of AMI was current smoking (odds ratio [OR] 3.6, p < 0.001) of cigarettes or beedis (a local form of tobacco), with individuals who currently smoked 10 or more per day having an OR of 6.7 (p < 0.001). History of hypertension and of overt diabetes mellitus were also independent risk factors (OR 2.69 [p = 0.001] and 2.64 [p = 0.004], respectively). Among all individuals, fasting blood glucose was a strong predictor of risk over the entire range, including at values usually regarded as normal (OR adjusted for smoking, hypertension, and WHR 1.62 for 1 SD increase, p < 0.001). Abdominal obesity (as measured by WHR) was also a strong independent predictor across the entire range of measures (OR adjusted for smoking, hypertension, and blood glucose 2.24 for 1 SD increase; p < 0.001). Compared with individuals with no risk factors, individuals with multiple risk factors had greatly increased risk of AMI (eg, OR of 10.6 for the group with smoking and elevated glucose). Lipid profile was not associated with AMI. In univariate analyses, higher socioeconomic (income) status (OR 0.32, p = 0.005 highest vs lowest; OR 0.75 middle vs lowest) and vegetarianism (OR = 0.55, p = 0.006), seemed to be protective. The impact of vegetarianism was closely correlated with blood glucose and WHR.

INTERPRETATION

Smoking cessation, treatment of hypertension, and reduction in blood glucose and central obesity (perhaps through dietary modification) may be important in preventing IHD in Asian Indians.

The usefulness of CT scanning in diagnosing dementia of the Alzheimer type

In order to determine the usefulness of Computerized Tomography (CT) scanning in making a diagnosis of dementia of the Alzheimer type, a group of patients diagnosed by NINCDS-ADRDA criteria (n = 22) were compared to a group of normal subjects (n = 49) using certain defined linear CT scan measurements. These measurements included specific measurements of the temporal lobes (temporal horns). Subjects were classified correctly 91.5% of the time with a high degree of probability. A diagnostic equation is presented which will allow testing of these methods in a prospective fashion.

The slowing of visual processing by hypoxia

An additive factors method (AFM) experiment was undertaken to determine whether the preprocessing and identification stages of information processing are implicated in the slowing of reaction time (RT) by hypoxia. The subjects (n = 14) responded at two levels of light intensity to pairs of lines that differed in length while breathing a low oxygen mixture that produced arterial oxyhaemoglobin saturations ranging between 64%-66%. The results showed a relatively large interaction between light intensity and hypoxia that was interpreted as evidence for slowing of the preprocessing stage. Differences in line length were plotted in terms of Crossman's confusion function and relatively small interactions with both hypoxia and light intensity were found, reflecting increases in slope. The light intensity x confusion level interaction was interpreted as evidence that AFM assumptions may not have been met completely in this experiment. This leads to the possibility that hypoxia slowed the identification stage indirectly rather than directly, although the latter hypothesis cannot be ruled out entirely at present. It is argued that visual slowing probably plays an important role in the disruption of perceptual-motor tasks by hypoxia.

P300 latency indexes nitrogen narcosis

This experiment investigated the effects of nitrogen narcosis on reaction time (RT) and P300 latency and amplitude. Ten subjects breathed either air or a non-narcotic 20% oxygen-80% helium (heliox) mixture in a hyperbaric chamber at 6.5, 8.3 and 10 atmospheres absolute (ATA). The subjects responded under controlled accuracy conditions to visually presented male or female names in an oddball paradigm. Single-trial analysis revealed a strong relationship between RT and P300 latency, both of which were slowed in a dose-related manner by hyperbaric air but not by heliox. A clear-cut dose-response relationship could not be established for P300 amplitude. These results indicate that P300 latency indexes nitrogen narcosis and are interpreted as support for the slowed processing model of inert gas narcosis.