Coronary Heart Disease
- Rosamond WD, Chambless LE, Folsom AR, et al [ Univ of North Carolina, Chapel Hill; Univ of Minnesota; Natl Heart, Lung, and Blood Inst,
Bethseda, Md; et al]
Trends in the Incidence of Myocardial Infarction and in Mortality Due to Coronary Heart Disease, 1987 to 1994
N Engl J Med 339: 861-867, 1998
Although mortality from Coronary heart disease [CHD] is known to have declined steadily in the USA in recent years, there is less information about the incidence of CHD during this period. Accurate measures of the incidence of CHD are needed to distinguish the effects of primary prevention from those of treatment. Researchers studied population based trends in mortality from CHD and in the incidence of myocardial infarction from 1987 to 1994.
Data were obtained from the Atherosclerosis Risk in Communities study, which examined the incidence of CHD in 4 areas of varying size in USA. Included in a surveillance of hospital admissions for myocardial infarction and of in-hospital and out-of-hospital deaths caused by CHD were 35- to 74-year old residents of the 4 communities. For the period between 1987 to 1994, it was estimated that there were 11,869 hospital admissions for myocardial infarction [on the basis of 8,572 admissions sampled] and 3,407 total coronary events [3,023 sampled].
White men showed the largest average annual decrease in CHD mortality [-4.9%], followed by white women [-4.5%], black women [-4.1%], and black men [-2.5%]. In- hospital mortality from CHD fell 5.1% and out-of-hospital mortality by 3.6% per year. The incidence of hospitalization for a first myocardial infarction remained stable overall and increased among black women [7.4% per year] and black men [2.9% per year]. Survival after myocardial infarction improved and recurrence rates decreased. The incidence of hospitalization for myocardial infarction was stable or increased slightly from 1987 to 1994. Mortality from CHD however, decreased significantly each year. Both medical care and secondary prevention have contributed to the decline in CHD mortality.
- Editorial –
Homocysteine : a novel risk factor for coronary heart disease in UK Indian Asians.
Heart 2001; 86: 121-122
Coronary Heart Disease has higher mortality in UK, Indian Asians than in Whites.
Recent studies show that plasma homocysteine concentrations are higher in UK Indian Asians than in European whites. The possibility that homocysteine is a risk factor for coronary heart disease is very real. Homocysteine levels can be reduced by supplementation with vitamin B, especially folic acid. A large scale interventionist study is recommended.
Lewis SJ, Sacks FM, Mitchell JS, et al [ Portland Cardiovascular Inst, Ore; Harvard Med School, Boston;
Baylor Univ, Dallas; et al]
Effects of Pravastatin on Cardiovascular Events in Women After Myocardial Infarction: The Cholesterol and Recurrent Events [CARE] Trial
J Am Coll Cardiol 32: 140-147, 1998
Because most participants in clinical trials of the effect of lipid-lowering treatment on cardiovascular disease have been men, there is little direct evidence of the benefits of this treatment on women. The Cholesterol and Recurrent Events [CARE] trial, which included 576 postmenopausal women, showed that pravastatin reduces the risk of cardiovascular events in women after myocardial infarction [MI].
Women in the CARE trial had a total cholesterol level of less than 240 mg/dL and low density lipoprotein level of 115 to 174 mg/dL. All entered the trial between 3 and 20 months after MI and were randomized to pravastatin [40mg/day] or matching placebo. Patients were followed for a median of 5 years for combined coronary events, coronary death or nonfatal MI, and stroke.
Compared with men in the CARE trial, women were older at randomization [61 vs 58] and had significantly higher prevalence of certain risk factors [including hypertension and diabetes]. Pravastatin had a similar effect on plasma lipids in women and men, with an average decrease of approximately 20% over 5 years. Women had a risk reduction of 43% for coronary death or nonfatal MI, 46% for combined coronary events, and 56% for stroke. The overall risk reduction was 46% for women and 20% for men.
Pravastatin therapy resulted in a strong, early reduction in recurrent coronary events in women with MI and with average cholesterol levels before treatment.
Hulley S, for the Heart and Estrogen/Progestin Replacement Study [HERS] Research Group [Univ of California, San Fransisco, Johns Hopkins Univ, Baltimore, Md; Wake Forest Univ, Winston-Salem, NC; et al]
Randomized Trial of Estrogen Plus Progestin for Secondary Prevention of Coronary Heart Disease in Postmenopausal Women
JAMA 280: 605-613, 1998
Observational studies report that coronary heart disease [CHD] rates are lower in postmenopausal women who take estrogen than in those who do not. However, this potential has not been confirmed in clinical trials. The effect of estrogen plus progestin therapy on risk of CHD events in postmenopausal women with established coronary disease was investigated in a randomized, blinded, placebo-controlled, secondary prevention trial.
A total of 2763 women with CHD seen in outpatient and community settings at 20 U.S. clinical centres were included. All were younger than 80 years, with a mean age of 66.7 years. All were postmenopausal and had an intact uterus. The women were given either daily doses of 0.625 mg of conjugated equine estrogens plus 2.5 mg of medroxyprogesterone acetate or placebo. The mean follow-up was 4.1 years. Eighty-two percent of the women assigned to hormone treatment were still using the therapy at the end of 1 year, and 75% at the end of 3 years.
The occurrence of nonfatal myocardial infarction or death from CHD was comparable in two groups, despite a net 11% lower low-density lipoprotein cholesterol level and 10% higher high-density lipoprotein cholesterol level in he hormone group. There was a significant time trend, with more CHD events occurring in the hormone group than the placebo group within the first year and fewer in years 4 and 5. A greater proportion of the women in the hormone group had venous thromboembolic events and gallbladder disease. Several other end points, for which the statistical power was limited, were also comparable between groups, including fractures, cancer and total mortality. Hormone treatment did not decrease the overall rate of CHD events in postmenopausal women with established coronary disease. However, it did increase the rate of thromboembolic events and gallbladder disease. Based on findings of no overall cardiovascular benefit and a pattern of early increase in the risk of CHD events, this treatment is not recommended for the secondary prevention of CHD. However, continuing this treatment in women already receiving it may be appropriate.
Rupprecht HJ, Darius H, Borkowski U, et al [ Johannes Gutenberg Univ, Mainz, Germany]
Comparison of Antiplatelet Effect of Aspirin, Ticlopidine, or Their Combination After Stent Implantation
Circulation 97: 1046-1052, 1998
With combined antiplatelet therapy using ticlopidine and aspirin to prevent subacute stent thrombosis, stenting has become a widely used interventional cardiology technique. Given the side effects of ticlopidine and aspirin, particularly neutropenia and gastointestinal bleeding respectively, it may be questioned whether these two drugs, alone or in combination, are sufficient to counteract platelet activation and aggregation after stenting. The effect of aspirin and/or ticlopidine on platelet activation and aggregation parameters were compared after stent implantation.
A total of 61 patients with stent implantation were studied. They were randomly assigned to 1 of 3 groups: group A received aspirin, 300 mg/day plus ticlopidine, 2 x 250 mg/day; group B received ticlopidine only and group C received aspirin only. Measurements of platelet activation were assessed on day 1, 7 and 14. Platelet aggregation in response to adenosine 5′ – diphosphate [ADP] and collagen was also evaluated.
From day 1 to day 14, collagen-induced platelet aggregation decreased from 62% to 37% in group A and from 68% to 58% in group B, with no significant change in group C. Platelet aggregation induced by ADP also decreased significantly in groups A and B, but not in group C.
Thus in patients receiving stents, combination of aspirin and ticlopidine has synergistic platelet inhibitory effects, and the combination is clearly superior to monotherapy with either drug alone, and is the treatment of choice.
Bech GJW, De Bruyne B, Bonnier HJRM, et al [ Catharine Hosp, Eindhoven, The Netherlands; Cardiovascular Ctr, Aalst, Belgium]
Long-Term Follow-up After Deferral of Percutaneous Angioplasty of Intermediate Stenosis on the Basis of Coronary Pressure Measurement
J Am Coll Cardiol 31: 841-847, 1998
Patients who have persistent typical or atypical chest pain with angiographically intermediate stenosis but without inducible ischemia pose a clinical challenge. Although these patients are at increased risk of a coronary event, the extent of risk is unknown. Some reliable technique of evaluating the functional significance of intermediate lesions would be useful in making decisions about the need for dilation.
The use of coronary pressure measurement and myocardial fractional flow reserve [FFR myo] in deciding the need for percutaneous transluminal coronary angioplasty [PTCA] in patients with intermediate stenosis was examined retrospectively.
During a 4-year period, guide wire-based coronary pressure measurements of FFRmyo were obtained in more than 600 patients. Of these, 100 patients were referred for PTCA of an intermediate stenosis in the middle or proximal part of native coronary artery but had the procedure deferred because of a pressure derived FFRmyo of 0.75 or greater. This level was regarded as showing that myocardial perfusion was adequate, and that the lesion could not be causing the patient’s chest pain. Subsequent management decisions were left to the referring physician. Follow-up clinical data were available in all patients; mean follow-up was 18 months.
Mean percent stenosis diameter in these patients was 47%. Two patients died of noncardiac causes during follow-up. Only 4 patients had an event related to the target vessel; one had a myocardial infarction related to the target vessel at 26 months. At 42 months, estimated survival was 97%, survival without target vessel-related events was 84%, and survival without any coronary event was 78%.
PTCA can be safely deferred in patients with intermediate stenosis if the FFRmyo is 0.75 or higher. The clinical event rate with deferral of PTCA is much lower than expected with PTCA.
Hennekens CH [Harvard Medical School, Boston]
Increasing Burden of Cardiovascular Disease: Directions for Research on Risk Factors
Circulation 97: 1095-1102, 1998
Heart disease is the leading cause of death for men aged 45 years and more, and women aged 65 years and more. One in 3 deaths results from heart disease, and there is evidence that cardiovascular disease mortality may be rising. Evidence on the burden of cardiovascular disease is reviewed, along with the direction of current and future research regarding risk factors.
Mortality from coronary heart disease [CHD] is higher in blacks than in whites [2.64/1000 vs 1.90/1000 for men and 1.62/1000 vs 0.98/1000 for women respectively]. Though mortality from CHD is declining, the decline is more among the whites. For U.S. adolescents, the rates of smoking and obesity are increasing, as the rate of physical activity declines. These trends will have long-standing consequences for overall CHD morbidity and mortality. These trends emphasize the need to intensify policy and research efforts in CHD treatment and prevention.
Though genetic factors make their contribution, environmental factors clearly play their role in CHD risk. There is proof that CHD risk can be reduced by control of smoking, high cholesterol and hypertension. Other risk factors are also proven, though possibility of modification is unclear. About half of the patients with CHD have no known risk factors. Studies of the multi-factorial causes of CHD have identified potential new disease markers, including the primary atherogenic marker hymocysteine, the primary thrombotic marker fibrinogen, and primary inflammatory markers such as C-reactive protein. Public education is an essential part of the CHD control. One in 3 women will die of CHD as against 1 in 25 who will die of breast cancer, and yet women perceive breast cancer as a major health risk. More intensive efforts and money would be needed in the future to help prevent CHD.
Wharton TP Jr, McNamara NS, Fedele FA, et al (Exeter Hosp, NH; Portsmouth Regional Hosp, NH)
Primary Angioplasty for the Treatment of Acute Myocardial Infarction Experience at Two Community Hospitals Without Cardiac Surgery
J Am Coll Cardiol 33: 1257-1265, 1999
Primary angioplasty in acute myocardial infarction (MI) decreases rates of death, stroke, recurrent ischaemia and infarction, but the question whether it is safe and effective in hospitals without cardiac surgery, has not been investigated. Experience with primary angioplasty when appropriate, at 2 hospitals without cardiac surgery, in 506 patients, over a 74 month period was analyzed.
Three experienced operators and 2 experienced catheterization laboratory teams performed 506 consecutive coronary angiograms with primary angioplasty in 489 patients with acute MI.
In 272 (53.7%) procedures, there were high-risk predictors (age over 75 years, anterior MI, out of hospital ventricular fibrillation); and in 246 (48.6%) procedures, there were angiographic high-risk predictors (50% stenosis of left main coronary artery, 70% stenosis of all 3 major epicardial coronary arteries, or ejection fraction less than 45%).
Primary immediate angioplasty was performed in 335 (66.2%) procedures and was successful in 94.3% at a median time of 94 minutes. The overall hospital mortality was 5.3% and the complication rate 7.1% (reinfarction 3%, stroke 1% and death 4%). The 6-month mortality was 1.4%.
Thus immediate coronary angiography with primary angioplasty in patients with acute MI is safe and effective.
Bauters C, Delomez M, Van Belle E, et al (Hopital Cardiologique, Lille, France)
Angiographically Documented Late Reocclusion After Successful Coronary Angioplasty of an Infarct-Related Lesion Is a Powerful Predictor of Long-Term Mortality
Circulation 99: 2243-2250, 1999
Three-month occlusion rates after successful thrombolytic therapy for an infarct-related artery (IRA) are as high as 30%. Six-month reocclusion rates after transluminal coronary angioplasty are also high. The long-term survival of patients with reocclusion were compared with those with no reocclusion of IRA at 6 months.
Angioplasty was performed immediately and successfully after myocardial infarction (MI) in 625 (92%) of 677 consecutive patients (71 women) over a 5 year period between 1988 to 1992.
At 6 months, 10 patients had died, 2 had undergone coronary by-pass surgery, 528 underwent repeat angiography and 83 refused angiography. Ninety patients (17%) (14 women) had reocclusion. Most (61%) of those with reocclusion had no symptoms, 27% had stable angina, 9% had unstable angina and 3% had a recurrent MI.
At a median follow-up of 5.7 years, 10% had died; 8% in the group without reocclusion and 20% in the group with reocclusion. Among patients with reocclusion, those with anterior MI had a higher mortality than the others.
Thus patients with late reocclusion of IRA, specially those with an anterior MI, have a significantly higher mortality than those with no reocclusion after angioplasty.
Muntwyler J, Hennekens CH, Buring JE, et al (Harvard Med School, Boston Veterans Affairs Med Ctr, Brockton / West Roxbury, Mass)
Mortality and Light to Moderate Alcohol Consumption After Myocardial Infarction
Lancet 352: 1882-1885, 1998
Light to moderate alcohol consumption is associated with decreased rates of cardiovascular and all-cause mortality. Patients with a history of myocardial infarction (MI) are at a increased risk of mortality from reinfarction and sudden death. They may benefit from light to moderate alcohol intake.
In a cohort of 90,105 men who provided information on alcohol intake and who had no medical history of cancer, stroke or liver disease, 5,358 had had an MI.
In a mean follow-up of 5 years, 920 participants had died. Compared with men who rarely or never drank, those who had 1 to 4 drinks a month had a relative risk of total mortality of 0.85; for those with 2 to 4 drinks per week the relative risk was 0.72; for those with 1 drink per day the risk rose to 0.79 and for those with 2 or more drinks per day the risk figure rose further to 0.84.
Thus heavy alcohol intake definitely increases the risk of death in all segments of the population. For patients with MI light to moderate alcohol intake (2 to 4 drinks per week) correlates with a lower risk of cardiovascular and total mortality rates.
Zijlstra F, Hoorntje JCA, de Boer MJ, et al (Hosp De Weezenlanden, Zwolle, The Netherlands)
Long-term Benefit of Primary Angioplasty Compared With Thrombolytic Therapy for Acute Myocardial Infarction
N Engl J Med 341: 1413-1419, 1999
Early restoration of blood flow after myocardial infarction reduced mortality by 20% to 30%. Primary coronary angioplasty results in higher rate of patency, lower stroke, and reinfarction rates, higher survival rates. Long-term morbidity and survival rates for patients randomly assigned to receive primary coronary angioplasty or intravenous streptokinase were compared.
Patients with acute myocardial infarction were randomly assigned to undergo primary angioplasty (n=194, 82% men) or to receive intravenous streptokinase (1.5 million units in 1 hour) (n=201, 79% men). Left ventricular ejection fractions were measured between 4 to 10 days after treatment. Patients were followed up for an average of 5 years, at which time patency was assessed by angiography.
At follow-up angiography there were 191 angioplasty patients and 196 streptokinase patients. Significantly more of the former had patent infarct-related vessel (90% vs. 65%); ejection fractions higher than 40%; lower death rates (13% vs. 24%); lower nonfatal reinfarction rates (6% vs. 22%). Rates of readmission for heart failure and ischaemia were also significantly lower for the angioplasty group (101 vs. 180 patients) as also were medical charges ($18,664 vs. $21,772).
Thus long-term clinical outcomes and costs are significantly improved for patients with myocardial infarction after primary coronary angioplasty as compared to intravenous streptokinase.
Ornish D, Scherwitz LW, Billings JH, et al (California Pacific Med Ctr, San Francisco; Univ of California, San Francisco; Univ of Texas, Houston; et al)
Intensive Lifestyle Changes for Reversal of Coronary Heart Disease
JAMA 280: 2001-2007, 1998
The Lifestyle Heart Trial tested whether patients with atherosclerosis could make and sustain comprehensive lifestyle changes that would reverse coronary heart disease.
In a randomized controlled trial between 1986 and 1992, 48 patients with moderate to severe coronary heart disease were randomly allocated to an intensive lifestyle change (experimental) or a usual care (control) group, and 35 underwent the 5-year follow-up coronary angiography. The intensive lifestyle-change program included a 10%-fat vegetarian diet, moderate aerobic exercise, stress management training, cessation of smoking, and psychosocial support.
During the study period, fat intake in the experimental group declined from 30% to 8.5%, cholesterol from 211 to 18.6 mg/dL, energy from 8,159 to 7,724 KJ, and protein from 17% to 15%; carbohydrates increased from 53% to 76.5%. In the control group fat intake decreased from 30% to 25%, cholesterol from 212.5 to 138.7 mg/dL, energy from 5.49 to 3.59 KJ, and protein from 19% to 18%; carbohydrate increased from 51% to 52%.
Patients in the experimental group lost 10.9 Kg in the first year and sustained a weight loss of 5.8 Kg in year 5, but the body mass of the control group did not change. At 5 years the low density lipoprotein levels in both groups were about 20% below baseline. Frequency of angina was reduced by 91% in the experimental group and by 72% in the control group. At 5 years the average percent stenosis declined by 3.1% in the experimental group and increased by 11.8% in the control group. During the trial, 25 cardiac events occurred in the experimental group as against 45 in the control group.
Sesso HD, Gaziano JM, Buring JE, et al (Harvard Med School, Boston; Veterans Affairs Med Ctr, Brockton/West Roxbury, Mass)
Coffee and Tea Intake and the Risk of Myocardial Infarction
Am J Epidemiol 149: 162-167, 1999
Reports vary regarding associations between caffeinated and decaffeinated coffee, tea, and myocardial infarction (MI). Black tea may be associated with a decreased incidence of MI, due to the flavinoids (compounds with antioxidant effect) which may retard atherosclerosis.
Three hundred and forty patients (340), aged 75 years and younger, with no history of MI or symptoms of MI less than 24 hours, were extensively interviewed.
The heaviest caffeinated coffee drinkers tended to be younger and male, to smoke cigarettes and to have type A personality. There was an association between drinking 2 or more cups of caffeinated coffee daily and higher rates of treatment for blood pressure and diabetes. Persons who consumed the most tea were older, smoked less and had more favorable high density lipoprotein cholesterol levels. Persons who drank 1 or more cups of tea daily had significantly lower risk of MI than those who did not drink tea.
Thus there was no association between caffeinated or decaffeinated coffee and risk of MI in this cohort. But there was significant reduction of MI in those who drank 1 or more cups of tea per day, independent of lipid and non-lipid coronary risk factors.
Rubins HB, for the Veterans Affairs High-Density Lipoprotein Cholesterol Intervention Trial Study Group (Veterans Affairs Med Ctr, Minneapolis)
Gemfibrozil for the Secondary Prevention of Coronary Heart Disease in Men with Low Levels of High-Density Lipoprotein Cholesterol
N Engl J Med 341: 410-418, 1999
Forty percent of patients with coronary heart disease have low-density lipoprotein (LDL) cholesterol levels below 130 mg/dL, and most of them have also low levels of high-density lipoprotein (HDL) cholesterol. Low levels of HDL are associated with higher risk of coronary artery disease. Efforts to raise HDL and lower triglycerides with gemfibrozil were studied in a double-blind trial.
Between September 1991 and June 1995, 2,531 patients with coronary heart disease were randomly assigned to receive 1,200 mgms of gemfibrozil (n=1,264) or placebo (n=1,267).
Compliance was 75% in both groups. During the study 418 patients died. At the end of the first year, gemfibrozil group had 6% higher HDL levels than the placebo group and 4% lower cholesterol and 31% lower triglyceride levels. LDL levels were similar in both groups throughout the study. A primary event, non-fatal myocardial infarction, occurred in 17.3% receiving gemfibrozil and in 21.7% of placebo group. Gemfibrozil reduced death rates from coronary heart disease by 22% and the effects began to be apparent 2 years after randomization.
Hannan EL, Racz MJ, McCallister BD, et al (State Univ of New York, Albany; Mid-American Heart Inst, Kansas City, Miss; Boston Univ, et al)
A Comparison of Three-Year Survival After Coronary Artery Bypass Graft Surgery and Percutaneous Transluminal Coronary Angioplasty
J Am Coll Cardiol 33: 63-72, 1999
Three-year risk adjusted survival rates for patients undergoing coronary artery bypass grafting (CABG) and percutaneous transluminal coronary angioplasty (PTCA) were prospectively compared, in 29,646 patients who had CABG and 29,930 who had PTCA between January 1993 and December 1995.
In-hospital mortality rates were 1.9% for CABG and 0.4% for PTCA and respective 3-year survival rates were 91.4% and 94.6%. CABG patients were significantly older, more likely to be men and to have lower ejection fractions.
During the follow-up 10.4% of PTCA patients underwent CABG surgery whereas 0.5% of CABG patients had repeat surgery and 2.8% had subsequent PTCA.
Both procedures have comparable results depending on the extent of lesions and site of the disease.
Buller CE, for the TOSCA Investigators (Vancouver Gen Hosp, BC, Canada; et al)
Primary Stenting Versus Balloon Angioplasty in Occluded Coronary Arteries: The Total Occlusion Study of Canada (TOSCA)
Circulation 100: 236-242, 1999
Long-term results after percutaneous transluminal coronary angioplasty (PTCA) for coronary occlusion are poor. Stenting of selected patients has not been tested. In a multi-center, controlled, randomized, prospective Total Occlusion Study of Canada (TOSCA) trial of heparin-coated Palmaz-Schatz stents in a diverse population of patients was analyzed.
A total of 410 patients with non-active coronary occlusions were randomly assigned to receive PTCA (n=208) or primary stenting with the heparin coated Palmaz-Schatz stent (n=202).
At 6 months follow-up, there were adverse cardiac events in 23.6% of PTCA patients and 23.3% of stent patients. In-hospital reintervention was necessary in 5 PTCA patients and 1 stent patient. Myocardial infarction occurred in 4 PTCA patients and 16 stent patients. No death occurred in either group. The procedure was completely successful in 68.8% of PTCA patients and 83.7% of stent patients. At angiographic follow-up in 392 patients, patency failure occurred in 21 (10.9%) of 191 stent patients and in 39 (19.5%) of 201 PTCA patients.
Primary stent placement reduces restenosis rates and improves 6-month patency rate compared with PTCA.
Domanski MJ, Exner DV, Borkowf CB, et al (Natl Heart, Lung and Blood Inst, Bethseda, Md; Harvard Med School, Boston)
Effect of Angiotensin Converting Enzyme Inhibition on Sudden Cardiac Death in Patients Following Acute Myocardial Infarction: A Meta-analysis of Randomized Clinical Trials
J Am Coll Cardiol 33: 598-604, 1999
Angiotensis Converting Enzyme (ACE) inhibitors have been known to reduce mortality after acute myocardial infarction but it is not known whether these drugs also decrease mortality from sudden cardiac death (SCD), which accounts for about one half of post-infarction deaths.
This study included 15 randomized controlled trials of administration of ACE inhibitors after myocardial infarction to 15,014 patients, all of whom were assigned either to ace-inhibitors or placebo within 14 days after myocardial infarction. All studies included at least 6 weeks blinded follow-up.
There were 2356 deaths (16%); 87% of deaths were from cardio-vascular causes and 38% were from SCD.
Studies with at least 500 patients showed significant reduction in the risk of SCD.
The risk of death overall was significantly reduced in patients receiving ace-inhibitors.
Ace-inhibitors appear to reduce the incidence of SCD by 20% and overall mortality after myocardial infarction.
Anand SS, for the SHARE Investigators (McMaster Univ, Hamilton, Ont, Canada)
Differences in Risk Factors, Atherosclerosis, and Cardiovascular Disease Between Ethnic Groups in Canada: The Study of Health Assessment and Risk in Ethnic Groups (SHARE)
Lancet 356: 279-284, 2000
Canadian studies have established significant ethnic variations in rates of cardiovascular disease. Canadians of South Asian origin have the highest incidence, those of European origin have intermediate incidence and those of Chinese origin have the lowest incidence. These differences are not explained by conventional risk factors. Other possible risk factors were explored.
The study included a random sample of 985 subjects; 342 of South Asian origin, 326 of European origin and 317 of Chinese origin. All were between 35 to 75 years of age and had lived in Canada for at least 5 years. Risk factors assessed included not only conventional ones of smoking, hypertension, diabetes, and cholesterol level but also prothrombofic markers fibrinogen, plasminogen activator inhibitor-1, lipoprotein (a), and homocysteine.
Across all groups, subjects with more severe carotid atherosclerosis had higher rates of cardiovascular disease which was 11% for South Asians, 5% for Europeans and 2% for Chinese. However, the Europeans had maximum intimal thickness 0.75 mm as against 0.72 mms for South Asians and 0.69 mms for Chinese. South Asians had higher prevalence of conventional and novel risk factors, such as glucose intolerance, high total and low-density lipoprotein cholesterol and triglyceride values; low high-density lipoprotein cholesterol levels; high levels of fibrinogen, homocysteine, lipoprotein (a), and plaminogen activator inhibitor-1.
Further studies are necessary to explain the higher incidence of such risk factors in South Asians.
Iribanen C, Sidney S, Bild DE, et al (Kaiser Permanente Med Care Program, Oakland, Calif; Natl Heart Lung, and Blood Inst, Bethseda, Md; Northwestern Univ, Chicago; et al)
Association of Hostility With Coronary Artery Calcification in Young Adults: The CARDIA Study
JAMA 283: 2546-2551, 2000
The Cook-Medley questionnaire is frequently used to measure hostility, which includes attitudinal, emotional, and behavioral components. The presence of hostility has been noted to predict coronary artery disease; this study sought to correlate hostility with coronary calcification.
Participants were drawn from those in the Coronary Artery Risk Development in Young Adults (CARDIA) study; during which coronary calcium scores were obtained. Hostility was assessed with Cook-Medley questionnaire at baseline and after 5 years. Ten years later, electron-beam CT scans were obtained.
The baseline and 5 year evaluation hostility scores correlation was 0.67, and overall hostility and cynical distrust scores showed a high level of correlation (0.82). Baseline and 5 year hostility score correlated with calcium score with a difference of 1 SD in hostility scores associated with significant possibility that coronary calcification was present. These correlations persisted even when adjustments were made for demographic, lifestyles, and physiologic variables.
Amongst adults with high levels of hostility corresponding degree of coronary artery calcification may be present.
Saito I, Folsom AR, Brancati FL, et al (Oita Med Univ, Japan; Univ of Minnesota, Minneapolis; John Hopkins Med Institutions, Baltimore, Md; et al)
Nontraditional Risk Factors for Coronary Heart Disease Incidence Among Persons with Diabetes: The Atherosclerosis Risk in Communities (ARIC) Study
Ann Intern Med 133: 81-91, 2000
In addition to traditional risk factors for coronary heart disease, type 2 diabetics have an excess risk which can be accounted for by nontraditional risk factors.
In the Atherosclerosis Risk in Communities (ARIC) Study, high-density (HDL) cholesterol lipoprotein, apolipoproteins, and haemostastic factors were investigated in adults with type 2 diabetes, to seek the independent role of these factors in causing coronary artery disease.
Baseline risks were recorded for 1676 patients with diabetes (43% men; 55% white), aged 45 to 64 years, without coronary artery disease. Patients were followed up from 1987 through 1995.
During follow-up, 186 patients developed coronary artery disease. These patients were older and more likely to be male and black. Patients with coronary artery disease were more likely to report less alcohol drinking; less likely to participate in sports; more likely to have hypertension and smoke; had higher levels of total cholesterol, low-density lipoprotein (LDL) cholesterol, and triglycerides and had lower levels of high-density lipoprotein (HDL) cholesterol. Among women who used hormone replacement therapy, 10% developed coronary artery disease but among women who did not have coronary artery disease, only 9.7% had hormone replacement therapy.
Sixteen nontraditional factors were identified: higher waist to hip ratios, and apolipoprotein B levels; lower levels of HDL, total cholesterol and apolipoprotein A, and albumin; higher levels of fibrinogen and non Willebrand factor; greater factor VII and factor VIII activity; and higher leukocyte counts. Patients taking insulin had more severe disease and had lower albumin levels.
Gaziano JM, Gaziano TA, Glynn RJ, et al (Brigham and Women’s Hosp, Boston; Harvard Med School, Boston; VA Boston Healthcare System; et al)
Light-to-Moderate Alcohol Consumption and Mortality in the Physicians’ Health Study Enrollment Cohort
J Am Coll Cardiol 35: 96-105, 2000
The relationship between heavy alcohol intake and increased mortality from a number of diseases – notably liver disease, cancer of oropharynx and esophagus, and non coronary heart disease – is widely accepted. Studies have suggested that there is reduction in total mortality with light to moderate intake of alcohol. The decrease is mainly in the reduction of cardiovascular heart disease (CVD) without any increases in other causes mortality. The relationship between light to moderate intake of alcohol and cause-specific mortality was investigated.
The prospective cohort included 89,299 male physicians in USA. All the subjects were between 40 and 84 years of age in 1982 and had no history of myocardial infarction, stroke, cancer or liver disease. Physicians filled in questionnaire reporting age, smoking status, cardiovascular risk factors, use of antihypertensive drugs, systolic and diastolic blood pressures, use of drugs to reduce cholesterol, frequency of vigorous exercise, history of angina or diabetes mellitus. Self reported height and weight were used to calculate body mass. Participants also reported on alcohol intake. Death from a variety of causes was used as the endpoint. A group of rarely/never drinkers was used as control.
In the 5.5 years follow-up there were 3216 deaths. Participants who consumed one drink per day or less had significantly lower rates of death than rarely/never drinkers. These who consumed 2 or more drinks per day had the highest reduction in mortality for cardiovascular disease. For cancers there was 28% increase in cancer (non-site specific) in those who had 2 or more drinks per day but this increase was not considered to be significant.
Haffner SM, Mykkanen L, Festa A, et al (Univ of Texas, San Antonio)
Insulin-Resistant Prediabetic Subjects Have More Atherogenic Risk Factors than Insulin-Sensitive Prediabetic Subjects: Implications for Preventing Coronary Heart Disease During the Prediabetic State
Circulation 101: 975-980, 2000
Whether insulin resitance or decreased insulin secretion is responsible for atherogenic prediabetic state and whether the cardiovascular risk factors were similar in the 2 groups of prediabetics was investigated.
Of 1734 subjects, aged 25 to 64 years, followed up for 7 years, type 2 diabetes was diagnosed in 195. Insulin resistance, fasting insulin, triglycerides, cholesterol, insulin secretion and blood pressure were determined at baseline and at follow-up.
Fasting insulin and insulin resistance were higher and insulin secretion was lower, in those who developed type 2 diabetes as compared to the rest. The individuals with insulin resistance had higher body mass index, larger waist circumference, higher blood pressure, triglyceride levels and lower high density lipoprotein cholesterol levels. Those with insulin resistance had higher incidence of cardiovascular disease than those who were insulin sensitive.
Stampfer MJ, Hu FB, Manson JE, et al (Howard Med.School, Boston, Howard School of Public Health, Boston)
Primary Prevention of Coronary Heart Disease in Women Through Diet and Lifestyle.
N.Eng.J.Med. 343; 16-22, 2000
Diet and lifestyle can have a dramatic effect on coronary heart disease. The effect of the combination was evaluated in women participating in the Nurses’ Health Study.
In 1976, a questionnaire was mailed to 121,700 female registered nurses in the USA, aged below 60 years, soliciting demographic information. In 1980 and later information about diet and physical activity were added.
The low risk group was defined as non-smoker, with body mass index less than 25, average daily alcohol intake of at least half a drink, daily moderate to vigorous physical activity for at least 30 minutes per day, a score in the highest 40th percentile of fiber, murine n-3 fatty acids and folate consumption, with high ratio of polyunsaturated to saturated fat consumption and diet low in trans fat and sugar.
During the 14 year follow-up there were 832 nonfatal MIs and 296 deaths from coronary artery disease, and 705 strokes among 84,129 studied. Each of these episodes occurred in women with multiple risk factors present.
Herrmann HC, Chang G, Klugherz BD, et al (Univ of Pennsylvania, Philadelphia)
Haemodynamic Effects of Sildenafil in Men With Severe Coronary Artery Disease
N Engl J Med 342: 1622-1626, 2000
Drugs used to treat erectile dysfunction can pose a hazard in men with severe heart disease. The systemic and coronary hemodynamic effects of sildenafil were measured in men with severe coronary artery disease.
The systemic, pulmonary, and coronary hemodynamic effects of oral sildenafil were measured in 14 men, average age 61 years, with severe stenosis averaging 78% but with stable symptoms.
Oral sildenafil slightly but significantly decreased arterial blood pressure and pulmonary pressure and increased coronary flow reserve over baseline values in diseased arteries. Average peak velocity increased nonsignificantly by 13% over baseline values. None of the men had an adverse event.
Thus oral sildenafil caused no adverse cardiovascular effects in men with severe coronary artery disease.