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.

Oral anticoagulant therapy in patients with coronary artery disease: a meta-analysis

CONTEXT

Despite years of use in coronary artery disease (CAD) and several studies of its effectiveness, the role of oral anticoagulants (OAs) remains controversial.

OBJECTIVE

To determine the effects of long-term OA therapy, stratified by the intensities of anticoagulation and aspirin therapy, on outcomes in patients with CAD.

DATA SOURCES

Studies were identified by MEDLINE, EMBASE, and CURRENT CONTENTS searches (1960-July 1999) and by reviewing reference lists and inquiring with experts and pharmaceutical companies.

STUDY SELECTION

Studies were included if they were published between 1960 and July 1999, were randomized, had recruited patients with CAD, who had used OA therapy for at least 3 months. Of 43 articles identified, 30 articles (31 trials) were analyzed.

DATA EXTRACTION

Information on type, duration, and method of monitoring OA therapy, as well as rates of death, myocardial infarction (MI), thromboembolic complications, stroke, and bleeding were abstracted by 2 independent observers.

DATA SYNTHESIS

With high-intensity (international normalized ratio [INR], 2.8-4.8) OAs vs control (16 trials, 10056 patients), clear reductions in mortality (odds reduction [ORed], 22%; 95% confidence interval [CI], 13%-31%), MIs (ORed, 42%; 95% CI, 34%-48%), and thromboembolic complications including stroke (ORed, 63%; 95% CI, 53-71%) were observed, but were associated with a 6.0-fold (95% CI, 4.4- to 8.2-fold) increase in major bleeding. For moderate OAs (INR, 2-3) vs control (4 trials, 1365 patients) the ORed for death was 18% (95% CI, -6% to 37%); for MI, 52% (95% CI, 37%-64%); and for stroke, 53% (95% CI, 19%-73%), but it increased bleeding by 7.7-fold (95% CI, 3.3- to 18-fold). For moderate- to high-intensity OAs (INR, > or =2) vs aspirin (7 trials, 3457 patients), no reduction in death, MI, or stroke was observed, and it was associated with a 2.4-fold (95% CI, 1.6- to 3.6-fold) increase in major bleeding. For moderate- to high-intensity OAs and aspirin vs aspirin alone (3 trials, 480 patients), the ORed for death, MI, or stroke was 56% (95% CI, 17%-77%) and major bleeding increased by 1.9-fold (0.6- to 6.0-fold). For low-intensity OAs (INR, <2.0) and aspirin vs aspirin alone (3 trials, 8435 patients), no significant reduction in death, MI, or stroke was observed, and major bleeding increased by 1.3-fold (95% CI, 1.0- to 1.8-fold).

CONCLUSIONS

Among patients with CAD, high-intensity and moderate-intensity OA are effective in reducing MI and stroke but increase the risk of bleeding. In the presence of aspirin, low-intensity OA does not appear to be superior to aspirin alone, while moderate- to high-intensity OA and aspirin vs aspirin alone appears promising and the bleeding risk is modest, but this requires confirmation from ongoing trials.

Low rates of preventive practices in patients with peripheral vascular disease

BACKGROUND

Patients with peripheral vascular disease (PVD) have a three-fold increased risk of myocardial infarction, stroke and death. Recently, a number of therapies have been demonstrated to prevent morbidity or mortality in patients with PVD or other arterial disease. Given the scarcity of data on the preventive practice patterns of this high risk patient group, the in-hospital management of patients admitted to hospital for a peripheral vascular intervention was reviewed.

PATIENTS AND METHODS

Charts of 195 patients with a diagnosis of peripheral arteriosclerotic disease (International Classification of Diseases, 9th revision, code 440.2) who were hospitalized at a tertiary care hospital in Ontario between June 1996 and June 1998 were reviewed.

RESULTS

The average age of patients admitted was 70.6 years, and 39% of patients were women. The main reason for admission was peripheral artery bypass graft surgery in 88% (172 of 195). Fifty-four per cent (106 of 195) of patients had clinically apparent coronary or cerebrovascular disease, and 92% (180 of 195) of patients had at least one cardiovascular disease risk factor. Fewer than half of all patients (49%) were discharged on any antithrombotic therapy (antiplatelet agent or anticoagulant), and a small proportion of patients were treated with a beta-blocker (20%) and cholesterol-lowering medications (16%).

CONCLUSIONS

The leading cause of morbidity and mortality in PVD patients is coronary and cerebrovascular disease. Despite this, the use of proven antithrombotic agents and other cardiac medications is suboptimal. Health professionals need to be aware of the high risk nature of the PVD population and to develop strategies to ensure that patient care is optimized.

Clinical Evidence: Emerging approaches in preventing cardiovascular disease

Images

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.

Homocyst(e)ine and cardiovascular disease: a critical review of the epidemiologic evidence

PURPOSE

To review epidemiologic studies on the association between homocyst(e)ine level and risk for cardiovascular disease and the potential benefits of homocysteine-decreasing therapies.

DATA SOURCES

Computerized and manual searches of the literature on total homocysteine levels and cardiovascular disease.

STUDY SELECTION

Prospective studies and major retrospective epidemiologic studies evaluating the association between homocyst(e)ine levels and cardiovascular disease and the association between blood levels or dietary intake of folate, vitamin B6, and vitamin B12 and cardiovascular disease.

DATA EXTRACTION

Relevant data on patient population, plasma homocyst(e)ine levels, duration of follow-up, and main results were extracted from studies that met the inclusion criteria.

DATA SYNTHESIS

The designs and results of studies included in this review are summarized. A formal meta-analysis was not performed because the studies were heterogeneous in method and design.

CONCLUSIONS

Results of epidemiologic studies suggest that moderately elevated plasma or serum homocyst(e)ine levels are prevalent in the general population and are associated with an increased risk for cardiovascular disease, independent of classic cardiovascular risk factors. Simple, inexpensive, nontoxic therapy with folic acid, vitamin B6, and vitamin B12 reduces plasma homocyst(e)ine levels. Although the association between homocyst(e)ine levels and cardiovascular disease is generally strong and biologically plausible, the data from the prospective studies are less consistent. In addition, epidemiologic observations of an association between hyperhomocyst(e)inemia and cardiovascular risk do not prove the existence of a causal relation. Therefore, the effectiveness of folate, vitamin B6, and vitamin B12 in reducing cardiovascular morbidity and mortality requires rigorous testing in randomized clinical trials. Several such trials are under way; their results may greatly affect cardiovascular morbidity and mortality, given the simplicity and low cost of vitamin therapy.

Design, baseline characteristics, and preliminary clinical results of the Organization to Assess Strategies for Ischemic Syndromes-2 (OASIS-2) trial

Despite use of heparin and aspirin, 5-10% of patients with unstable angina develop myocardial infarction (MI) or refractory angina in the hospital. We tested the hypothesis that recombinant hirudin (lepirudin), a direct thrombin inhibitor, is superior to heparin, an indirect thrombin inhibitor, in patients with acute ischemic syndromes who were receiving aspirin. Patients (n = 10,141) with unstable angina or suspected acute MI without ST-segment elevation were randomly assigned heparin (5,000-U bolus, then 15-U/kg per hour infusion; n = 5,058) or hirudin (0.4-mg/kg bolus, then 0.15-mg/kg per hour infusion; n = 5,083) for 72 hours in a double-blind trial. The primary outcome measure was cardiovascular death or new MI at 7 days. Analysis was by intention to treat. At 7 days, 213 patients (4.2%) in the heparin group and 182 (3.6%) in the hirudin group had experienced cardiovascular death or new MI (relative risk = 0.84; 95% CI = 0.69-1.02; p = 0.077). The number of patients with cardiovascular death, new MI, or refractory angina at 7 days was 340 (6.7%) with heparin and 284 (5.6%) with hirudin (relative risk = 0.82; 95% CI = 0.70-0.96; p = 0.0125). These differences were primarily observed during the 72-hour treatment period (cardiovascular death or MI relative risk = 0.76; 95% CI = 0.59-0.99; p = 0.039; cardiovascular death, MI, or refractory angina relative risk = 0.78; 95% CI = 0.63-0.96; p = 0.019). Although there was an excess of major bleeding with hirudin requiring transfusion (59 [1.2%] vs 34 [0.7%] with heparin; p = 0.01), there was no excess in life-threatening episodes (20 in each group) or strokes (14 in each group). Data from the Organization to Assess Strategies for Ischemic Syndromes (OASIS)-2 trial suggest that a direct thrombin inhibitor, recombinant hirudin, is more effective than an indirect thrombin inhibitor, heparin, in preventing cardiovascular death, MI, or refractory angina. Recombinant hirudin also has an acceptable safety profile in patients with unstable angina or acute MI without ST-segment elevation.

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.

Candesartan in heart failure--assessment of reduction in mortality and morbidity (CHARM): rationale and design. Charm-Programme Investigators

BACKGROUND

Chronic heart failure (CHF) is an increasing burden to health care. Pharmacological treatment with angiotensin-converting enzyme (ACE) inhibitors and beta blockers improve survival and reduce hospitalizations in patients with low left ventricular ejection fraction (LVEF). Despite these therapies, morbidity and mortality remains problematic. Furthermore, 30% to 50% of patients with CHF have a preserved LVEF. It is not known if treatments are of benefit in this group.

DESIGN

Candesartan in Heart Failure-Assessment of Reduction in Mortality and Morbidity (CHARM) is a program designed to investigate the clinical usefulness of the long-acting angiotensin II type 1 receptor blocker, candesartan cilexetil, in a broad spectrum of patients with symptomatic heart failure. Patients with systolic dysfunction, tolerant or intolerant to an ACE-inhibitor, and patients with preserved systolic function are included. Specifically, the CHARM program consists of 3 independent, parallel, placebo-controlled studies in patients with (1) LVEF less than or equal to 40%, ACE-inhibitor treated (n = 2,300); (2) LVEF less than or equal to 40%, ACE-inhibitor intolerant (n = 1,700); (3) LVEF greater than 40%, not treated with ACE inhibitors (n = 2,500). The 3 studies will be combined to evaluate the effect of candesartan cilexetil on all-cause mortality in the broad spectrum of symptomatic heart failure. The primary objective in each trial is to evaluate the effects on the combined endpoint of cardiovascular mortality or CHF hospitalization. Other endpoints include the effects on myocardial infarction, all-cause hospitalization, and resource utilization. CHARM is intended to randomize 6,500 patients with symptomatic heart failure from 26 countries in Europe, the United States, Canada, South Africa, and Australia. The CHARM program started to enroll patients in March 1999. The follow-up period is a minimum of 2 years. The study is expected to end in the third quarter of 2002.

The role of digitalis in the treatment of heart failure

Over the past 200 years, digoxin has been commonly used to treat patients with congestive heart failure. Clinical trials have demonstrated the benefits of the use of digoxin on exercise tolerance, ejection fraction, and neurohormone production. The Digoxin Investigators Group trial has recently provided strong evidence for the long-term benefits of digoxin on morbidity for patients with heart failure. This article will review the evidence of the benefits of digoxin and its current role in the treatment of patients with congestive heart failure.

Contemporary management of patients with left ventricular systolic dysfunction. Results from the Study of Patients Intolerant of Converting Enzyme Inhibitors (SPICE) Registry

AIMS

The reported prevalence of angiotensin-converting enzyme (ACE) inhibitor use in patients with heart failure varies considerably. Recent reports suggest that many patients who could benefit from such therapy are not receiving ACE inhibitors. The Study of Patients Intolerant of Converting Enzyme Inhibitors (SPICE) Registry was established to understand better the demographics, characteristics, and contemporary use of ACE inhibitors in an international registry.

METHODS AND RESULTS

Between August 1996 and April 1997, each of 105 study centres from eight countries in North America and Europe was invited to review retrospectively the medical records of 100 consecutive patients with left ventricular ejection fractions </=35%. The median age of the 9580 Registry patients was 66 years, 26% were women, the median ejection fraction was 27%, and the primary aetiology of left ventricular dysfunction was ischaemic (63%). Eighty percent of patients were receiving ACE inhibitors. The most common reason for non-use of ACE inhibitors was intolerance (9%).

CONCLUSION

The SPICE Registry provides a contemporary description of the demographics and management of patients with documented left ventricular systolic dysfunction. The contemporary use of ACE inhibitors (80%) appears to be higher than previously reported and the main reason for non-use is perceived intolerance (9%).

Cardiovascular and cancer mortality among Canadians of European, south Asian and Chinese origin from 1979 to 1993: an analysis of 1.2 million deaths

BACKGROUND

Cardiovascular disease and cancer are important health problems worldwide, yet our knowledge of these conditions is derived principally from populations of European descent. To investigate ethnic variations in major causes of death in Canada, the authors examined total and cause-specific mortality among European, south Asian, and Chinese Canadians.

METHODS

Canadians of European, south Asian and Chinese origin were identified in the Canadian Mortality Database by last name and country of birth and in the population census by self-reported ethnicity. Age-standardized death rates by cause, per 100,000 population, were calculated for ages 35 to 74 years from 1979 to 1993 and in 5-year intervals grouped around census years (1979/83, 1984/88 and 1989/93).

RESULTS

Rates of death from ischemic heart disease were highest among Canadians of south Asian origin (men 320.2, women 144.5) and European origin (men 319.6, women 109.9) and were markedly lower among Canadians of Chinese origin (men 107.0, women 40.0); the rates declined significantly in all 3 groups over the study period. Rates of death from cerebrovascular disease were relatively low and showed less ethnic variation (Canadian men of European, south Asian and Chinese origin 49.5, 47.0 and 45.8 respectively; Canadian women of European, south Asian and Chinese origin 34.8, 39.0 and 42.2 respectively) and declined similarly in all groups over time. Rates of death from cancer were highest among Canadians of European origin (men 343.6, women 236.2), intermediate among those of Chinese origin (men 258.1, women 161.6) and lowest among those of south Asian origin (men 122.3, women 131.3). Over time, cancer mortality increased in Canadians of European origin but remained constant or declined in those of south Asian and Chinese origin.

INTERPRETATION

Substantial differences exist in rates of death from ischemic heart disease and cancer among European, south Asian and Chinese Canadians.

Summary of randomized trials of angiotensin converting enzyme inhibitors

Angiotensin converting enzyme (ACE) inhibitors have been shown to reduce the risk of death, worsening heart failure and recurrent infarction in patients with left ventricular dysfunction and heart failure. They have also been shown to reduce mortality in the acute phase of myocardial infarction. They have been demonstrated to reduce major vascular events and progression of renal disease in diabetes with hypertension, compared to placebo and to calcium channel blockers. Current trials are evaluating their role in preventing major vascular events in patients with coronary artery disease, strokes and Type II diabetes who are normotensive.

Recurrent events in meta-analysis of multiple clinical trials

AIM

To study the efficacy and safety of drug or therapy with recurrent events in meta-analysis of multiple clinical trials.

METHODS

A nonparametric approach is proposed to estimate the rates of recurrent events for meta-analysis of trials. The method was used in meta-analysis of angiotensin-converting enzyme (ACE) inhibitor clinical trials to analyze the relative rates and the excess rates between ACE inhibitor and placebo treatment groups for endpoints of hospitalizations for CHF, hospitalizations for CHF or cardiac death, and hospitalizations for CHF or any death, respectively.

RESULTS

The estimates of those three endpoints were 69%, 74%, and 76% (P < 0.01). Compared with placebo, ACE inhibitor reduced 30 cases of hospitalizations for CHF per 1000 person-years, or 40 cardiac deaths or hospitalizations for CHF per 1000 person-years (P < 0.01).

CONCLUSION

The method was a simple and efficient approach to conduct meta-analysis of clinical trials with recurrent events.

Increased winter mortality from acute myocardial infarction and stroke: the effect of age

OBJECTIVES

We examined seasonal variations in mortality from acute myocardial infarction (AMI) and stroke by age using 300,000 deaths in the Canadian Mortality Database for the years 1980 to 1982 and 1990 to 1992.

BACKGROUND

The effect of age on environmental determinants of AMI and stroke is not well understood.

METHODS

Seasonal variations were analyzed by month and for the four seasons (winter beginning in December). A chi-square test was used to test for homogeneity at p < 0.01, and relative risk ratios (RRs) for high and low periods were determined in relation to the overall mean. For each of four age subgroups, the magnitude of the seasonal variation was reported as the difference in mortality between the highest and lowest frequency seasons.

RESULTS

By month, AMI deaths were highest in January (RR = 1.090) and lowest in September (RR = 0.904), a relative risk difference of 18.6%. The seasonal mortality variation in AMI deaths (winter vs. summer) increased with increasing age: 5.8% for <65, 8.3% for 65 to 74, 13.4% for 75 to 84 and 15.8% for >85 years (p < 0.005 for trend). Stroke mortality peaked in January (RR = 1.113) and had a trough in September (RR = 0.914), a relative risk difference of 19.9%. The seasonal variation in stroke mortality also increased with age. Seasonal variations were not seen in those aged <65 years, compared with 11.6% for 65 to 74, 15.2% for 75 to 84 and 19.3% for >85 years (p < 0.005 for trend).

CONCLUSIONS

The elderly demonstrate a greater winter increase in AMI and stroke mortality than younger individuals. An understanding of these seasonal patterns may provide novel avenues for research in cardiovascular disease prevention.

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.

The relationship between glucose and incident cardiovascular events. A metaregression analysis of published data from 20 studies of 95,783 individuals followed for 12.4 years

OBJECTIVE

To assess the relationship between nondiabetic glucose levels and cardio vascular risk.

RESEARCH DESIGN AND METHODS

Three independent searches using MEDLINE (1966-1996), followed by a manual search of the references from each retrieved article, were conducted by two physicians and one medical librarian. Data had to be reported in at least three quantiles or intervals so that the nature of the relationship between glucose and cardiovascular events (i.e., linear or nonlinear) could be explored, and to ensure that any incremental cardiovascular risk was consistent across quantiles or intervals.

RESULTS

Analyzed studies comprised 95,783 people (94% male) who had 3,707 cardiovascular events over 12.4 years (1,193,231 person-years). Studies reporting fasting glucose levels (n = 6), 2-h glucose levels (n = 7), 1-h glucose levels (n = 5), and casual glucose levels (n = 4) were included. The glucose load used varied from 50 to 100 g. The highest glucose interval for most studies included glucose values in the diabetic range. The relationship between glucose levels and the risk of a cardiovascular event was modeled for each study and the beta-coefficients were combined. Compared with a glucose level of 4.2 mmol/l (75 mg/dl), a fasting and 2-h glucose level of 6.1 mmol/dl (110 mg/dl) and 7.8 mmol/l (140 mg/dl) was associated with a relative cardiovascular event risk of 1.33 (95% CI 1.06-1.67) and 1.58 (95% CI 1.19-2.10), respectively.

CONCLUSIONS

The progressive relationship between glucose levels and cardiovascular risk extends below the diabetic threshold.