Differences in risk factors, atherosclerosis and cardiovascular disease between ethnic groups in Canada: the study of health assessment and risk in ethnic groups (SHARE)

Cardiovascular disease rates vary greatly between ethnic groups in Canada. To establish whether this variation can be explained by differences in disease risk factors and subclinical atherosclerosis, we undertook a population-based study of three ethnic groups in Canada: South Asians, Chinese and Europeans. A total of 985 participants were recruited from three cities (Hamilton, Toronto and Edmonton) by stratified random sampling. Clinical cardiovascular disease was defined by history or electrocardiographic findings. Carotid atherosclerosis was measured with B-mode ultrasonography. Conventional (smoking, hypertension, diabetes, raised cholesterol) and novel risk factors (markers of a prothrombotic state) were measured. Within each ethnic group and overall, the degree of carotid atherosclerosis was associated with a higher prevalence of cardiovascular disease. South Asians had the highest prevalence of this condition compared with Europeans and Chinese (11%, 5% and 2%, respectively; p=0.0004). Despite this finding, Europeans had more atherosclerosis (mean of the maximum intimal medial thickness 0.75 [0.16] mm) than South Asians (0.72 [0.15] mm) and Chinese (0.69 [0.16] mm). South Asians had an increased prevalence of glucose intolerance, higher total and low-density lipoprotein cholesterol, higher triglycerides and lower high-density lipoprotein cholesterol, and much greater abnormalities in novel risk factors including higher concentrations of fibrinogen, homocysteine, lipoprotein(a), and plasminogen activator inhibitor-1. Although there are differences in conventional and novel risk factors between ethnic groups, this variation and the degree of atherosclerosis only partly explains the higher rates of cardiovascular disease among South Asians compared with Europeans and Chinese. The increased risk of cardiovascular events could be due to factors affecting plaque rupture, the interaction between prothrombotic factors and atherosclerosis, or as yet undiscovered risk factors.

Lysozyme levels for the diagnosis of tuberculous effusions in children

Lysozyme level was measured in the fluid and serum of 42 tuberculous (25 pleural, 11 ascites and 6 pericardial) and 29 non-tuberculous (5 malignant, 9 empyema thoracis, 10 transudative ascites and 5 pyopericardium) effusions. The mean fluid lysozyme level was significantly raised in tuberculous pleural, ascites, and pericardial effusions in comparison to malignant pleural (p <0.001), transudative ascites (p < 0.001), and pyopericardium (p < 0.02) cases, respectively. The mean fluid/serum lysozyme ratio did not differ significantly between tuberculous and their corresponding non-tuberculous effusions. The confirmed tuberculous pleural effusion patients had significantly higher mean fluid lysozyme level and fluid/serum lysozyme ratio when compared with clinical cases (p < 0.05). The cut-off fluid lysozyme level of > or = 50/UI(-1) and fluid/serum lysozyme ratio of > or = 1.1 were considered for the diagnosis of tuberculous effusions; the sensitivity and specificity of fluid lysozyme and fluid/serum lysozyme ratios were 100, 100 per cent, and 97.6, 33.3 per cent, respectively, on excluding the patients with purulent effusions. A significant correlation was observed between the fluid and serum lysozyme levels in tuberculous effusions (r = 0.39,p < 0.01). Thus, fluid lysozyme was found to be a better and reliable test than fluid/serum lysozyme ratio for the diagnosis of tuberculous effusions in children.

Incidence, predictive factors, and prognostic significance of supraventricular tachyarrhythmias in congestive heart failure

BACKGROUND

The incidence, predictive factors, morbidity, and mortality associated with the development of supraventricular tachyarrhythmias (SVTs) in patients with congestive heart failure (CHF) are poorly defined.

METHODS

In the Digitalis Investigation Group trial, patients with CHF who were in sinus rhythm were randomly assigned to digoxin (n = 3,889) or placebo (n = 3,899) and followed up for a mean of 37 months. Baseline factors that predicted the occurrence of SVT and the effects of SVT on total mortality, stroke, and hospitalization for worsening CHF were determined.

RESULTS

Eight hundred sixty-six patients (11.1%) had SVT during the study period. Older age (odds ratio [OR], 1.029 for each year increase in age; p = 0.0001), male sex (OR, 1.270; p = 0.0075), increasing duration of CHF (OR, 1.003 for each month increase in duration of CHF; p = 0.0021), and a cardiothoracic ratio of > 0.50 (OR, 1.403; p = 0.0001) predicted an increased risk of experiencing SVT. Left ventricular ejection fraction, New York Heart Association functional class, and treatment with digoxin vs placebo were not related to the occurrence of SVT. After adjustment for other risk factors, development of SVT predicted a greater risk of subsequent total mortality (risk ratio [RR] = 2.451; p = 0.0001), stroke (RR = 2.352; p = 0.0001), and hospitalization for worsening CHF (RR = 3. 004; p = 0.0001).

CONCLUSION

In CHF patients in sinus rhythm, older age, male sex, longer duration of CHF, and increased cardiothoracic ratio predict an increased risk for experiencing SVT. Development of SVT is a strong independent predictor of mortality, stroke, and hospitalization for CHF in this population. Prevention of SVT may prolong survival and reduce morbidity in CHF patients.

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.

Current status of safety and efficacy of calcium channel blockers in cardiovascular diseases: a critical analysis based on 100 studies

Recently, serious concerns have been expressed about the long-term safety of the calcium channel blockers (CCBs) as a group. Safety and efficacy are, however, ultimately linked to each other; therefore both must be evaluated especially in the therapy of angina and hypertension, the main clinical indications for CCBs. The structural, functional, and pharmacokinetic heterogeneity of CCBs means that the efficacy and dangers of one subclass, such as the short-acting dihydropyridines (DHPs), in one situation, such as unstable angina, do not necessarily apply in other clinical situations. One hundred studies are reviewed according to their methods of data collection: case series, case control, cohort, randomized controlled trials (RCTs), and meta-analyses. Large, well-designed RCTs and the meta-analyses based on these trials remain the gold standard. Observational studies, though potentially less reliable sources of information because of selection bias, may nevertheless produce hypotheses that must then be tested in RCTs. Regarding safety, both observational studies and RCTs suggest that adverse effects of CCBs may be linked to short-acting agents, specifically short-acting nifedipine. Two good studies favor the safety of verapamil, even in short-acting form. Incomplete but increasing overall evidence favors the safety of longer-acting DHPs. Heart failure remains a class contraindication to the use of all CCBs, with some exceptions. Regarding efficacy, there are positive results of RCTs with CCBs in 2 specific clinical situations, namely, verapamil in postinfarct protection in the absence of pre-existing heart failure, and 2 outcome studies on hypertension with longer acting DHPs. These results cannot automatically be applied to other clinical situations and to other CCBs. For example, there is no evidence for the safety or efficacy of DHPs used without beta blockers in postinfarct patients. In diabetic hypertensives, 2 relatively large RCTs show that the blood pressure can be reduced by DHP-based therapy in diabetics, with a reduction in hard end points. To achieve current blood pressure goals, combination therapy is almost always necessary, and in diabetics there is strong evidence that 1 essential component should be an angiotensin converting enzyme inhibitor. The future aim with CCBs must be to obtain a large database gathered from RCTs, which will give the same certainty about efficacy and safety that already holds for use of the diuretics in hypertension, beta-blockers in postmyocardial infarction patients, and the angiotensin converting enzyme inhibitors in heart failure.

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.

Impact of diabetes on long-term prognosis in patients with unstable angina and non-Q-wave myocardial infarction: results of the OASIS (Organization to Assess Strategies for Ischemic Syndromes) Registry

BACKGROUND

Although unstable coronary artery disease is the most common reason for admission to a coronary care unit, the long-term prognosis of patients with this diagnosis is unknown. This is particularly true for patients with diabetes mellitus, who are known to have a high morbidity and mortality after an acute myocardial infarction.

METHODS AND RESULTS

Prospectively collected data from 6 different countries in the Organization to Assess Strategies for Ischemic Syndromes (OASIS) registry were analyzed to determine the 2-year prognosis of diabetic and nondiabetic patients who were hospitalized with unstable angina or non-Q-wave myocardial infarction. Overall, 1718 of 8013 registry patients (21%) had diabetes. Diabetic patients had a higher rate of coronary bypass surgery than nondiabetic patients (23% versus 20%, P:<0.001) but had similar rates of catheterization and angioplasty. Diabetes independently predicted mortality (relative risk [RR], 1.57; 95% CI, 1.38 to 1.81; P:<0.001), as well as cardiovascular death, new myocardial infarction, stroke, and new congestive heart failure. Moreover, compared with their nondiabetic counterparts, women had a significantly higher risk than men (RR, 1.98; 95% CI, 1.60 to 2.44; and RR, 1.28; 95% CI, 1.06 to 1.56, respectively). Interestingly, diabetic patients without prior cardiovascular disease had the same event rates for all outcomes as nondiabetic patients with previous vascular disease.

CONCLUSIONS

Hospitalization for unstable angina or non-Q-wave myocardial infarction predicts a high 2-year morbidity and mortality; this is especially evident for patients with diabetes. Diabetic patients with no previous cardiovascular disease have the same long-term morbidity and mortality as nondiabetic patients with established cardiovascular disease after hospitalization for unstable coronary artery disease.

Risk of intracranial haemorrhage with bolus versus infusion thrombolytic therapy: a meta-analysis

BACKGROUND

Although thrombolytic therapy given by bolus injection seems to be as effective as infusion over 60-90 min, no single trial has been adequately powered to detect clinically important safety differences between the two strategies. We did a meta-analysis to find out whether bolus administration of thrombolytics is associated with an increased frequency of intracranial haemorrhage.

METHODS

We identified randomised trials comparing bolus with infusion thrombolytic therapy by a search of electronic databases, reference lists, and conference proceedings. Odds ratios for primary intracranial haemorrhage, non-haemorrhagic stroke, mortality, and reinfarction were calculated for each trial and were combined in a fixed-effects model.

FINDINGS

Seven trials, involving a total of 103,972 patients, met our inclusion criteria. Bolus treatment was associated with an increased risk of intracranial haemorrhage compared with infusion (0.8 vs 0.6%; odds ratio 1.25 [95% CI 1.08-1.45]; p=0.003). The increased risk was most striking in trials comparing bolus with infusion administration of the same agent (1.75 [1.32-2.33], p=0.0001), but was also evident in trials comparing a newer-generation bolus agent with standard infusion therapy (1.25 [1.03-1.50]; p=0.02). The rates of non-haemorrhagic stroke (0.94 [0.81-1.09]), 30-day mortality (1.01 [0.97-1.06]), or reinfarction (1.04 [0.97-1.11]) did not differ between the two strategies.

INTERPRETATION

The increased risk of bolus thrombolytic treatment seems to be primarily associated with the method of administration rather than properties of the agents. Although the increased risk of intracranial haemorrhage is small, physicians should balance this risk against the putative benefits of easier administration with no difference in mortality or reinfarction.

The impact of time to thrombolytic treatment on outcome in patients with acute myocardial infarction. For the CORE investigators (Collaborative Organisation for RheothRx Evaluation)

OBJECTIVES

To examine the impact of time to thrombolytic treatment on multiple acute outcome variables in a single trial of thrombolysis in acute myocardial infarction.

DESIGN AND PATIENTS

Mortality and reinfarction rate were measured in 2770 patients with acute myocardial infarction who received thrombolysis within 12 hours in CORE, an international, dose ranging trial of poloxamer 188. Tc-99m sestamibi infarct size and radionuclide angiographic ejection fraction substudies included 1099 and 1074 patients, respectively.

RESULTS

Time to thrombolysis, subgrouped by intervals (< 2, 2-4, > or = 4-6, and > or = 6 hours), was significantly associated with infarct size (median 15.0%, 18.5%, 22.0%, 18.5% of left ventricle; p = 0.033), mean (SD) ejection fraction (51.5 (12.0)%, 48. 3 (13.9)%, 48.2 (13.3)%, 48.2 (15.0)%; p = 0.006), 35 day mortality (5.7%, 7.1%, 7.9%, 12.5%; p = 0.0004), six month mortality (7.3%, 8. 6%, 10.4%, 15.5%; p < 0.0001), and 35 day reinfarction rate (6.1%, 3. 2%, 4.0%, 0.9%; p = 0.0001).

CONCLUSIONS

In this single large trial, the beneficial effect of time to thrombolysis on infarct size and ejection fraction was restricted to treatment given within two hours of symptom onset, while the effect on mortality was evident over all time intervals. Reinfarction rate was higher in patients treated with earlier thrombolysis.

Glucose and insulin abnormalities relate to functional capacity in patients with congestive heart failure

AIMS

In addition to diabetes mellitus, less severe abnormalities of glucose and insulin metabolism may be related to functional status in patients with heart failure. We examined the relationship of hyperglycaemia (> or =6.1 mmol. l(-1)) and hyperinsulinaemia (> or =11.2 mU. l(-1)) to functional status and cardiac function in patients with heart failure.

METHODS AND RESULTS

Fasting plasma glucose and insulin levels were obtained in 663 heart failure patients. The average left ventricular ejection fraction was 0.28+/-0.07, 63% were in New York Heart Association Functional Class (NYHA-FC) I/II and 37% were in NYHA-FC III/IV. Twenty seven percent had diabetes mellitus, but an additional 8% had undiagnosed diabetes mellitus (glucose > or =7 mmol. l(-1)) and 9% had glucose levels between 6.1 and 7 mmol. l(-1), so that a total of 43% (287) of patients had elevated glucose levels (> or =6.1 mmol. l(-1)). In general, more diabetic patients had NYHA-FC III/IV symptoms, shorter 6 min walk distances, but similar left ventricular ejection fractions compared to non-diabetic patients. The non-diabetic patients in NYHA-FC III/IV had higher glucose and insulin levels than patients in NYHA-FC I/II (6.3+/-0.2 vs 5.6+/-0.1 mmol. l(-1), P<0.001 and 19.6+/-2.3 vs 10. 2+/-0.6 mU. l(-1), P<0.001). Non-diabetic patients with elevated glucose levels had shorter 6 min walk distances compared to those with normal glucose levels (368.2+/-8 m vs 389.+/-4 m, P=0.02), however, left ventricular ejection fraction was similar.

CONCLUSION

Glucose abnormalities are extremely common in heart failure patients (43% of patients). Diabetes mellitus and hyperglycaemia or hyperlinsulinaemia in non-diabetic patients were related to worse symptomatic status but not worsening left ventricular ejection fraction compared to patients with normal glucose and insulin levels.

Differences in risk factors, atherosclerosis, and cardiovascular disease between ethnic groups in Canada: the Study of Health Assessment and Risk in Ethnic groups (SHARE)

BACKGROUND

Cardiovascular disease rates vary greatly between ethnic groups in Canada. To establish whether this variation can be explained by differences in disease risk factors and subclinical atherosclerosis, we undertook a population-based study of three ethnic groups in Canada: South Asians, Chinese, and Europeans.

METHODS

985 participants were recruited from three cities (Hamilton, Toronto, and Edmonton) by stratified random sampling. Clinical cardiovascular disease was defined by history or electrocardiographic findings. Carotid atherosclerosis was measured with B-mode ultrasonography. Conventional (smoking, hypertension, diabetes, raised cholesterol) and novel risk factors (markers of a prothrombotic state) were measured.

FINDINGS

Within each ethnic group and overall, the degree of carotid atherosclerosis was associated with a higher prevalence of cardiovascular disease. South Asians had the highest prevalence of this condition compared with Europeans and Chinese (11%, 5%, and 2%, respectively, p=0.0004). Despite this finding, Europeans had more atherosclerosis (mean of the maximum intimal medial thickness 0.75 [0.16] mm) than South Asians (0.72 [0.15] mm), and Chinese (0.69 [0.16] mm). South Asians had an increased prevalence of glucose intolerance, higher total and LDL cholesterol, higher triglycerides, and lower HDL cholesterol, and much greater abnormalities in novel risk factors including higher concentrations of fibrinogen, homocysteine, lipoprotein (a), and plasminogen activator inhibitor-1.

INTERPRETATION

Although there are differences in conventional and novel risk factors between ethnic groups, this variation and the degree of atherosclerosis only partly explains the higher rates of cardiovascular disease among South Asians compared with Europeans and Chinese. The increased risk of cardiovascular events could be due to factors affecting plaque rupture, the interaction between prothrombotic factors and atherosclerosis, or as yet undiscovered risk factors.

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

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

Unfractionated heparin and low-molecular-weight heparin in acute coronary syndrome without ST elevation: a meta-analysis

BACKGROUND

In acute coronary syndrome without ST elevation, the role of unfractionated and low-molecular-weight heparin in aspirin-treated patients remains unclear, and there is conflicting evidence regarding the efficacy and safety of low-molecular-weight heparin (LMWH) relative to unfractionated heparin. We did a systematic overview of the randomised trials to assess the effect of unfractionated heparin and LMWH on death, myocardial infarction, and major bleeding.

METHODS

Randomised trials comparing unfractionated heparin or LMWH with placebo or untreated control, or comparing unfractionated heparin with LMWH, for the short-term and long-term management of patients with acute coronary syndrome without ST elevation, were identified by electronic and manual searches and through contact with experts and industry representatives. Odds ratios for death, myocardial infarction, and major bleeding were calculated for each trial, and results for the individual trials were combined by a modification of the Mantel-Haenszel method.

FINDINGS

12 trials, involving a total of 17157 patients, were included. The summary odds ratio (OR) for myocardial infarction or death during short-term (up to 7 days) unfractionated heparin or LMWH compared with placebo or untreated control was 0.53 (95% CI 0.38-0.73; p=0.0001) or 29 events prevented per 1000 patients treated; during short-term LMWH compared with unfractionated heparin was 0.88 (0.69-1.12; p=0.34); and during long-term LMWH (up to 3 months) compared with placebo or untreated control was 0.98 (0.81-1.17; p=0.80). Long-term LMWH was associated with a significantly increased risk of major bleeding (OR 2.26, [95% CI 1.63-3.14], p<0.0001), which is equivalent to 12 major bleeds per 1000 patients treated.

INTERPRETATION

In aspirin-treated patients with acute coronary syndrome without ST elevation, short-term unfractionated heparin or LMWH halves the risk of myocardial infarction or death. There is no convincing difference in efficacy or safety between LMWH and unfractionated heparin. Long-term LMWH has not been proven to confer benefit additional to aspirin and there is no evidence to support its use after the first 7 days.

Clinical effects of early angiotensin-converting enzyme inhibitor treatment for acute myocardial infarction are similar in the presence and absence of aspirin: systematic overview of individual data from 96,712 randomized patients. Angiotensin-converting Enzyme Inhibitor Myocardial Infarction Collaborative Group

OBJECTIVES

We sought to determine whether the clinical effects of early angiotensin-converting enzyme (ACE) inhibitor (ACEi) treatment for acute myocardial infarction (MI) are influenced by the concomitant use of aspirin (ASA).

BACKGROUND

Aspirin and ACEi both reduce mortality when given early after MI. Aspirin inhibits the synthesis of vasodilating prostaglandins, and, in principle, this inhibition might antagonize some of the effects of ACEi. But it is uncertain whether, in practice, this influences the effects of ACEi on mortality and major morbidity after MI.

METHODS

This overview sought individual patient data from all trials involving more than 1,000 patients randomly allocated to receive ACEi or control starting in the acute phase of MI (0-36 h from onset) and continuing for four to six weeks. Data on concomitant ASA use were available for 96,712 of 98,496 patients in four eligible trials (and for none of 1,556 patients in the one other eligible trial).

RESULTS

Overall 30-day mortality was 7.1% among patients allocated to ACEi and 7.6% among those allocated to control, corresponding to a 7% (standard deviation [SD], 2%) proportional reduction (95% confidence interval 2% to 11%, p = 0.004). Angiotensin-converting enzyme inhibitor was associated with similar proportional reductions in 30-day mortality among the 86,484 patients who were taking ASA (6% [SD, 3%] reduction) and among the 10,228 patients who were not (10% [SD, 5%] reduction: chi-squared test of heterogeneity between these reductions = 0.4; p = 0.5). Angiotensin-converting enzyme inhibitor produced definite increases in the incidence of persistent hypotension (17.9% ACEi vs. 9.4% control) and of renal dysfunction (1.3% ACEi vs. 0.6% control), but there was no good evidence that these effects were different in the presence or absence of ASA (chi-squared for heterogeneity = 0.4 and 0.0, respectively; both not significant). Nor was there good evidence that the effects of ACEi on other clinical outcomes were changed by concomitant ASA use.

CONCLUSIONS

Both ASA and ACEi are beneficial in acute MI. The present results support the early use of ACEi in acute MI, irrespective of whether or not ASA is being given.

Effects of physiologic pacing versus ventricular pacing on the risk of stroke and death due to cardiovascular causes. Canadian Trial of Physiologic Pacing Investigators

BACKGROUND

Evidence suggests that physiologic pacing (dual-chamber or atrial) may be superior to single-chamber (ventricular) pacing because it is associated with lower risks of atrial fibrillation, stroke, and death. These benefits have not been evaluated in a large, randomized, controlled trial.

METHODS

At 32 Canadian centers, patients without chronic atrial fibrillation who were scheduled for a first implantation of a pacemaker to treat symptomatic bradycardia were eligible for enrollment. We randomly assigned patients to receive either a ventricular pacemaker or a physiologic pacemaker and followed them for an average of three years. The primary outcome was stroke or death due to cardiovascular causes. Secondary outcomes were death from any cause, atrial fibrillation, and hospitalization for heart failure.

RESULTS

A total of 1474 patients were randomly assigned to receive a ventricular pacemaker and 1094 to receive a physiologic pacemaker. The annual rate of stroke or death due to cardiovascular causes was 5.5 percent with ventricular pacing, as compared with 4.9 percent with physiologic pacing (reduction in relative risk, 9.4 percent; 95 percent confidence interval, -10.5 to 25.7 percent [the negative value indicates an increase in risk]; P=0.33). The annual rate of atrial fibrillation was significantly lower among the patients in the physiologic-pacing group (5.3 percent) than among those in the ventricular-pacing group (6.6 percent), for a reduction in relative risk of 18.0 percent (95 percent confidence interval, 0.3 to 32.6 percent; P=0.05). The effect on the rate of atrial fibrillation was not apparent until two years after implantation. The observed annual rates of death from all causes and of hospitalization for heart failure were lower among the patients with a physiologic pacemaker than among those with a ventricular pacemaker, but not significantly so (annual rates of death, 6.6 percent with ventricular pacing and 6.3 percent with physiologic pacing; annual rates of hospitalization for heart failure, 3.5 percent and 3.1 percent, respectively). There were significantly more perioperative complications with physiologic pacing than with ventricular pacing (9.0 percent vs. 3.8 percent, P<0.001).

CONCLUSIONS

Physiologic pacing provides little benefit over ventricular pacing for the prevention of stroke or death due to cardiovascular causes.

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.

Randomized trial of candesartan cilexetil in the treatment of patients with congestive heart failure and a history of intolerance to angiotensin-converting enzyme inhibitors

BACKGROUND

Many patients with congestive heart failure do not receive the benefits of angiotensin-converting enzyme (ACE) inhibitors because of intolerance. We sought to determine the tolerability of an angiotensin II receptor blocker, candesartan cilexetil, among patients considered intolerant of ACE inhibitors.

METHODS

Patients with CHF, left ventricular ejection fraction less than 35%, and history of discontinuing an ACE inhibitor because of intolerance underwent double-blind randomization in a 2:1 ratio to receive candesartan (n = 179) or a placebo (n = 91). The initial dosage of candesartan was 4 mg/d; the dosage was increased to 16 mg/d if the drug was tolerated. A history of intolerance of ACE inhibitor was attributed to cough (67% of patients), hypotension (15%), or renal dysfunction (11%).

RESULTS

The study drug was continued for 12 weeks by 82.7% of patients who received candesartan versus 86.8% of patients who received the placebo. This 4.1% greater discontinuation rate with active therapy was not significant; the 95% confidence interval ranged from 4.8% more discontinuation with placebo to 13% more with candesartan. Titration to the 16-mg target dose was possible for 69% of patients who received candesartan versus 84% of those who received the placebo. Frequencies of death and morbidity were not significantly different between the candesartan and placebo groups (death 3.4% and 3.3%, worsening heart failure 8.4% and 13.2%, myocardial infarction 2.8% and 5.5%, all-cause hospitalization 12.8% and 18.7%, and death or hospitalization for heart failure 11.7% and 14.3%).

CONCLUSIONS

Candesartan was well tolerated by this population. The effect of candesartan on major clinical end points, including death, remains to be determined.

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.

Enalapril prevents clinical proteinuria in diabetic patients with low ejection fraction

OBJECTIVE

Clinical proteinuria is a risk factor for both end-stage renal disease and cardiovascular disease. The prevalence of clinical proteinuria, its correlates and predictive value, and the effect of ACE inhibitors in preventing clinical proteinuria in diabetic and nondiabetic patients with left ventricular (LV) dysfunction are unknown.

RESEARCH DESIGN AND METHODS

The Studies of Left Ventricular Dysfunction (SOLVD) trials were analyzed to determine the baseline distribution of clinical proteinuria and related cardiovascular risk factors, the effect of baseline proteinuria on the risk of hospitalization for congestive heart failure (CHF) and mortality, and the effect of enalapril in preventing new clinical proteinuria.

RESULTS

A total of 5,487 out of 6,797 SOLVD participants (81%) were assessed for proteinuria at baseline. A total of 177 patients (3.2%) had baseline proteinuria. These patients had significantly higher systolic (137 vs. 125 mmHg, P < or = 0.001) and diastolic (83 vs. 77 mmHg, P < or = 0.001) blood pressure levels, a higher prevalence of diabetes (41 vs. 18%, P < or = 0.001), a lower ejection fraction (26.2 vs. 27.3%, P < or = 0.05), and greater degree of CHF (New York Heart Association [NYHA] class III/IV in 22 vs. 10%, P < or = 0.001) than patients without baseline proteinuria. Patients with baseline proteinuria also had higher rates of hospitalization for CHF (relative risk 1.81 [95% CI 1.37-2.41], P = 0.0001) and mortality (1.73 [1.34-2.24], P = 0.0001). Enalapril prevented clinical proteinuria in diabetic patients (0.38 [0.17-0.81], P = 0.0123) but not in nondiabetic patients (1.43 [0.77-2.63], P = 0.2622) without baseline proteinuria.

CONCLUSIONS

Clinical proteinuria is an independent predictor of hospitalization for CHF and mortality in diabetic and nondiabetic patients with LV dysfunction. Enalapril significantly reduces the risk of clinical proteinuria in diabetic patients with LV dysfunction.

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.