Recanalization of thrombosed superficial femoral arteries with a hydraulic thrombectomy catheter in a canine model.

OBJECTIVE: This experiment was conducted to evaluate efficacy and safety of the Oasis thrombectomy catheter on arterial thrombosis in dogs. MATERIALS AND METHODS: Thrombosis was induced in 18 femoral arteries of nine mongrel dogs. Recanalization of the thrombosed femoral artery was performed using a thrombectomy catheter 7-10 days after thrombus induction. Pre- and postprocedural arterial status was documented by angiography. After mechanical thrombectomy, the animals were sacrificed and the femoral arteries were harvested and examined macro- and microscopically. Additionally, in vitro fragmentation was carried out to determine particle size and distribution from the recovered effluent. RESULTS: Subacute thrombosis was successfully created in 15 femoral arteries. Full recanalization was achieved in 80% (12/15) of the thrombosed femoral arteries without any residual thrombus. No significant downstream embolization was documented angiographically. Endothelial denudation was observed in all the treated arteries along with occasional disruption of the internal elastic lamina. No medial injury was seen. Ninety-eight percent of thrombus was liquefied, defined as particles smaller than 15 microm, by the catheter. Particles larger than 400 microm represented 0.27% of the original clot weight. CONCLUSION: Occluded femoral arteries with 7- to 10-day-old thrombus can be efficiently recanalized with the Oasis catheter in dogs without any significant complication. This thrombectomy catheter appears to be highly effective and safe and requires no sophisticated equipment. Blood loss was our major concern regarding use of this catheter but can be minimized by strictly controlling activation time and restricting the inflow into the vascular segment being treated.

Prevalence and extent of atherosclerosis in adolescents and young adults: implications for prevention from the Pathobiological Determinants of Atherosclerosis in Youth Study.

CONTEXT: Atherosclerosis, the underlying cause of coronary heart disease, has been shown to be present even in young adults. OBJECTIVE: To document the extent and severity of atherosclerosis in adolescents and young adults in the United States. DESIGN AND SETTING: The Pathobiological Determinants of Atherosclerosis in Youth Study, a multi-institutional autopsy study conducted in US medical centers. Subjects A total of 2876 study subjects, between 15 and 34 years old, black and white, men and women, who died of external causes and underwent autopsy between June 1, 1987, and August 31, 1994. MAIN OUTCOME MEASURES: Extent, prevalence, and topography of atherosclerotic lesions. RESULTS: Intimal lesions appeared in all the aortas and more than half of the right coronary arteries of the youngest age group (15-19 years) and increased in prevalence and extent with age through the oldest age group (30-34 years). Fatty streaks were more extensive in black subjects than in white subjects, but raised lesions did not differ between blacks and whites. Raised lesions in the aortas of women and men were similar, but raised lesions in the right coronary arteries of women were less than those of men. The prevalence of total lesions was lower in the right coronary artery than in the aorta, but the proportion of raised lesions among total lesions was higher in the right coronary artery than in the aorta. CONCLUSIONS: Atherosclerosis begins in youth. Fatty streaks and clinically significant raised lesions increase rapidly in prevalence and extent during the 15- to 34-year age span. Primary prevention of atherosclerosis, as contrasted with primary prevention of clinically manifest atherosclerotic disease, must begin in childhood or adolescence.

Autopsy diagnoses of malignant neoplasms: how often are clinical diagnoses incorrect?

CONTEXT: Autopsy often reveals new diagnoses of malignant neoplasms, but as technological advances to improve diagnosis during life have improved, autopsy rates have declined dramatically. OBJECTIVE: To determine if there is still a high discordance rate between clinical and autopsy diagnoses of malignant neoplasms despite increasing technological advances in diagnostic methods. DESIGN AND SETTING: A 10-year retrospective study (1986-1995) of all autopsies performed at the Medical Center of Louisiana at New Orleans. PARTICIPANTS: All patients autopsied, excluding preterm fetuses, at the Medical Center of Louisiana at New Orleans, by both Tulane and Louisiana State University Schools of Medicine in which consent was obtained or authorization given from the Orleans Parish Coroner's Office. MAIN OUTCOME MEASURES: Discordance between clinical and autopsy diagnoses of malignant neoplasms. RESULTS: A total of 1625 cases were reviewed of which 520 preterm fetuses were excluded. Of the remaining 1105 cases, 654 were male and 451 were female. The mean age was 48.3 years (range, 1-98 years). A total of 433 neoplasms were diagnosed, 250 of which were malignant. One hundred eleven malignant neoplasms in 100 patients had been either undiagnosed or misdiagnosed, and in 57 patients, the immediate cause of death could be attributed to the malignant neoplasm. The discordance between clinical and autopsy diagnoses of malignant neoplasms in this study is 44%, which is similar to previously reported studies. CONCLUSION: The discordance rate between clinical and autopsy diagnoses of malignant neoplasms is large and confirms the importance of the postmortem examination.

Confirmed previous infection with Chlamydia pneumoniae (TWAR) and its presence in early coronary atherosclerosis.

BACKGROUND: Chlamydia pneumoniae has been identified in coronary atheroma, but concomitant serum antibody titers have been inconsistently positive and unavailable before the detection of early or advanced atherosclerotic lesions. METHODS AND RESULTS: This retrospective investigation was performed on premortem serum specimens and autopsy tissue from 60 indigenous Alaska Natives at low risk for coronary heart disease, selected by the potential availability of their stored specimens. Serum specimens were drawn a mean of 8.8 years (range, 0.7 to 26.2 years) before death, which occurred at a mean age of 34.1 years (range, 15 to 57 years), primarily from noncardiovascular causes (97%). Coronary artery tissues were independently examined histologically and, for C pneumoniae organism and DNA, by immunocytochemistry (ICC) and polymerase chain reaction (PCR) with species-specific monoclonal antibody and primers. Microimmunofluorescence detected species-specific IgG, IgA, and IgM antibody in stored serum. C pneumoniae, frequently within macrophage foam cells, was identified in coronary fibrolipid atheroma (raised lesions, Stary types II through V) in 15 subjects (25%) and early flat lesions in 7 (11%) either by PCR (14, 23%) or ICC (20, 33%). The OR for C pneumoniae in raised atheroma after a level of IgG antibody > or =1:256 >8 years earlier was 6.1 (95% CI, 1.1 to 36.6) and for all coronary tissues after adjustment for multiple potential confounding variables, including tobacco exposure, was 9.4 (95% CI, 2.6 to 33.8). CONCLUSIONS: Serological evidence for C pneumoniae infection frequently precedes both the earliest and more advanced lesions of coronary atherosclerosis that harbor this intracellular pathogen, suggesting a chronic infection and developmental role in coronary heart disease.

Association between multiple cardiovascular risk factors and atherosclerosis in children and young adults. The Bogalusa Heart Study.

BACKGROUND: In adults, cardiovascular risk factors reinforce each other in their effect on cardiovascular events. However, information is scant on the relation of multiple risk factors to the extent of asymptomatic atherosclerosis in young people. METHODS: We performed autopsies on 204 young persons 2 to 39 years of age, who had died from various causes, principally trauma. Data on antemortem risk factors were available for 93 of these persons, who were the focus of this study. We correlated risk factors with the extent of atherosclerosis in the aorta and coronary arteries. RESULTS: The extent of fatty streaks and fibrous plaques in the aorta and coronary arteries increased with age. The association between fatty streaks and fibrous plaques was much stronger in the coronary arteries (r=0.60, P<0.001) than in the aorta (r=0.23, P=0.03). Among the cardiovascular risk factors, body-mass index, systolic and diastolic blood pressure, and serum concentrations of total cholesterol, triglycerides, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol, as a group, were strongly associated with the extent of lesions in the aorta and coronary arteries (canonical correlation [a measure of the association between groups of variables]: r=0.70; P<0.001). In addition, cigarette smoking increased the percentage of the intimal surface involved with fibrous plaques in the aorta (1.22 percent in smokers vs. 0.12 percent in nonsmokers, P=0.02) and fatty streaks in the coronary vessels (8.27 percent vs. 2.89 percent, P=0.04). The effect of multiple risk factors on the extent of atherosclerosis was quite evident. Subjects with 0, 1, 2, and 3 or 4 risk factors had, respectively, 19.1 percent, 30.3 percent, 37.9 percent, and 35.0 percent of the intimal surface covered with fatty streaks in the aorta (P for trend=0.01). The comparable figures for the coronary arteries were 1.3 percent, 2.5 percent, 7.9 percent, and 11.0 percent, respectively, for fatty streaks (P for trend=0.01) and 0.6 percent, 0.7 percent, 2.4 percent, and 7.2 percent for collagenous fibrous plaques (P for trend=0.003). CONCLUSIONS: These findings indicate that as the number of cardiovascular risk factors increases, so does the severity of asymptomatic coronary and aortic atherosclerosis in young people.

Comparison of atherosclerosis in alaska Natives and nonnatives.

OBJECTIVE: To test the hypothesis that Alaska Natives have fewer atherosclerotic lesions in the coronary arteries and aorta than nonnative Alaska residents. DESIGN: Systematic standardized collection and evaluation of coronary arteries and aortas collected at autopsy. SETTING: Forensic autopsy service in Alaska. SUBJECTS: One hundred thirty Alaska Natives and 115 Alaska nonnatives who underwent forensic autopsy between February 1989 and December 1993. INTERVENTION: None. MAIN OUTCOME MEASURES: Prevalence and extent of atherosclerotic lesions in the aortas and coronary arteries in both populations studied. RESULTS: Alaska Natives had significantly lower prevalence and extent of raised atherosclerotic lesions in the abdominal aorta and coronary arteries than nonnative Alaska residents. CONCLUSIONS: Differences in coronary heart disease mortality between Alaska Natives and nonnatives are, at least in part, the result of fewer atherosclerotic lesions in Alaska Natives.

Blood pressure in people in Greenland assessed by measuring renovasculopathies of hypertension at autopsy.

Surveys taken of blood pressure in Greenland indicated prevailing levels similar to those in the USA. Morphometrically measured renovasculopathies in 88 autopsies confirmed blood pressure levels comparable to the survey findings. At clinic visits, the recorded blood pressures in 48 of the autopsies verified the morphometric conclusions (r = 0.559). By all three approaches, similar levels of blood pressure were determined for the population of Greenland. The agreements in outcome from these approaches serve to substantiate the validity of all three methods. The overall outcome verifies a previous report placing Greenland among the nations which experience rapid rise of blood pressure with age and high prevalence rates for hypertension.

Renovasculopathies of nephrosclerosis in relation to atherosclerosis at ages 25 to 54 years.

Renovasculopathies of hypertension include arteriolar hyalinization and arterial intimal fibroplasia. Atherosclerotic features of coronary arteries and aorta include fatty streaks and raised lesions. Data were obtained from a series of 573 autopsies of black and Caucasian males and females aged 25 to 54 years, who died of violent and natural causes unrelated to atherosclerosis. Analysis showed positive correlations of coronary and aortic raised lesions with arteriolar hyalinization. Arterial intimal fibroplasia correlated positively with raised lesions in the aorta but only weakly and inconsistently in the coronary arteries. The extent of fatty streaks in the coronaries, as in the aorta, did not correlate with either form of renovasculopathy. These results provide evidence that hyalinization of renal arterioles may be a marker for young people who have the most advanced coronary atherosclerosis, and who therefore have an early start upon a course toward coronary heart disease later in life.

The Inuit diet. Fatty acids and antioxidants, their role in ischemic heart disease, and exposure to organochlorines and heavy metals. An international study.

Traditional food is culturally, economically and nutritionally important for the Greenlandic Inuit people. In the 1970s the preventive effect of marine fat on cardiovascular disease, thrombosis and atherosclerosis was described. The low incidence of ischemic heart disease among Greenlanders has been related to the high intake of marine food. Since 1990 routine autopsies have taken place in two towns in Greenland, Nuuk and Ilulissat. The autopsies represent 26% of the total number of deaths in these two towns. Samples have been collected from 104 autopsies. International cooperative studies have analysed specimens in relation to ischemic heart disease as a benefit related to diet, as well as the level of heavy metals and organochlorine in organs as a risk related to diet. High amounts of mono-unsaturated and Omega-3 poly-unsaturated fatty acid were found in adipose tissue. Liver analyses of selenium have confirmed the expected high intake among Greenlanders. Reduced atherosclerotic lesions were found in the coronary arteries. Blood pressure levels calculated from renovascholopathia of hypertension indicate prevailing levels similar to those in industrialized countries. Some factors in Greenland may be protecting the coronary arteries, thereby of setting the expected effect of hypertension. The level of methyl mercury in organs is generally high. PCB concentrations found in organs of Greenlanders are higher than among other populations. Health and risk effects of the traditional foods need further investigation.

Risk factors and atherosclerosis in youth autopsy findings of the Bogalusa Heart Study.

The Collaborative Pathology Study is one of the most impressive programs of the Bogalusa Heart Study. Attempts are made to obtain complete and uniform necropsy coverage of all decreased young people who may have been examined in the Bogalusa Heart Study. Since 1978, autopsy specimens have been collected from 190 deaths, representing 65% of all known deaths in the study age category. The relation of antemortem risk factors for cardiovascular disease to early atherosclerotic lesions in the aorta and coronary arteries was assessed in those individuals previously examined in the Bogalusa Heart Study (N = 59). Aortic fatty streaks were strongly related to both total and low-density lipoprotein (LDL) cholesterol (r = 0.62, P < 0.0001 for each association), and were inversely correlated with the ratio of high-density lipoprotein (HDL) cholesterol to LDL plus very-low-density lipoprotein (VLDL) cholesterol (r = -0.29, P < 0.01). Coronary artery fatty streaks were associated with elevated total cholesterol, LDL cholesterol, VLDL cholesterol, and systolic blood pressure. Higher levels of LDL and VLDL cholesterol, triglycerides, systolic and diastolic blood pressure, and a lower ratio of HDL to LDL plus VLDL were found in those people with coronary artery fibrous plaques. Microscopy offered additional information about the characteristics of the aortic and coronary arterial intimal disease. Histologic observations have confirmed some of the relationships indicated with gross observations and show the complexity of this disease process. These findings emphasize the importance of an approach to preventive cardiology early in life.

Histologic features of atherosclerosis and hypertension from autopsies of young individuals in a defined geographic population: the Bogalusa Heart Study.

Histologic features of arterial intima have been quantified at autopsy by morphometric methods in 66 individuals aged 6-30 years, in whom cardiovascular risk factors had been measured prospectively prior to death. Measures of serum cholesterol were found to correlate significantly with the extent of foam cell infiltration seen in paraffin sections and the intensity of lipid staining in frozen sections of the abdominal and thoracic segments of the aorta. A similar correlation in the coronary arteries was weak and inconsistent. Blood pressure was significantly correlated with foam cells and stainable lipid in the abdominal but not the thoracic segment of the aorta. A similar correlation in the coronary arteries was significant, but only in males, and most consistently in the black males. Intimal thickness of the coronary arteries showed sporadic and weak correlations with blood pressure and lipids; however, a strong and consistent correlation was seen between coronary intimal thickness and hyalinization of renal arterioles. With many statistical tests carried out on a limited data set, some particular details are, no doubt, spuriously significant; however, some persistent patterns are beginning to emerge. The reproducible findings support the concept that prospective measurements of blood pressure and serum lipids are associated with a degree of structural characteristics present in children and young adults. Moreover, the observed structural characteristics, specifically the deposition of lipids in the intima of coronary arteries and aorta, are likely to reflect variations in the rates of progression of atherosclerosis.

Long-term induction and regression of diet-induced atherosclerotic lesions in rhesus monkeys. II. Morphometric evaluation of lesions by light microscopy in coronary and carotid arteries.

Atherosclerotic lesions were induced in rhesus monkeys (Macaca mulatta) by feeding them a high-saturated fatty acid and high-cholesterol diet. After 5.4 years the extent of lesions in three major coronary arteries and the right carotid artery was evaluated morphometrically by light microscopy in one group of animals (group P). The remaining animals were switched to a low-cholesterol diet that remained high in saturated fatty acids and provided the same percentage of total calories as did the atherogenic diet. Lesion regression was then evaluated in one group of monkeys 1.9 years (group R4) and in another group of monkeys 3.7 years (group R5) after withdrawal of cholesterol alone from the diet. In group P, the mean intimal thickness varied between 26 and 47 microns, maximum intimal thickness between 70 and 92 microns, and luminal reduction between 9% and 12% in the three major coronary arteries. Luminal reduction varied between 1% and 11% in right carotid artery segments. After 1.9 years of consuming the basal diet, group R4 animals were no different from group P animals with respect to morphometric measures. Total intimal and medial areas of the left anterior descending (LAD) coronary artery in groups P and R4 were also similar. In contrast, after 3.7 years of consuming the basal diet, group R5 animals showed consistently although not statistically significantly lower values than those in group P for the morphometric measures in coronary arteries and total intimal area in the LAD. Similar results were obtained for the common carotid and external carotid arteries. Thus, our study shows that long-term diet-induced lesions in coronary arteries and in common and external segments of the right carotid artery regressed only when the animals were fed the basal diet for 3.7 years. We conclude that atherosclerotic lesions induced in coronary and carotid arteries can regress toward normal to a certain extent, but they require a longer time for regression than do other arterial segments. These findings support the results of clinical trials in human subjects.

Long-term induction and regression of diet-induced atherosclerotic lesions in rhesus monkeys. I. Morphological and chemical evidence for regression of lesions in the aorta and carotid and peripheral arteries.

Atherosclerotic lesions were induced in rhesus monkeys by feeding a high-saturated fatty acid and high-cholesterol diet. After 5.4 years the extent of fatty streaks and raised lesions was evaluated in one group of animals (group P) by visual estimation in 10 arterial segments and chemically in four arterial segments. The remaining animals were switched to a basal regression diet low in cholesterol but high in saturated fatty acids for up to 3.7 years. Regression of lesions was evaluated in one group for 1.9 years (group R4) and in another for 3.7 years (group R5) after deleting cholesterol from the diet. The atherogenic diet increased serum cholesterol levels in all animals from a mean of 150 mg/dL to a mean of about 430 mg/dL. The atherogenic diet produced lesions in group P in all arterial segments (involving up to 50% of the arterial intimal surface) and increased cholesterol content in four arterial segments (varying between 443 and 506 micrograms/cm2). Switching to the basal regression diet decreased serum cholesterol levels to normal after 12 to 18 weeks. The switch to the basal diet significantly decreased the extent of fatty streaks in most arterial segments in both groups. Although differences in the mean extent of raised lesions among groups were not statistically significant, 7 of 10 arterial segments in group R4 and 9 of 10 segments in group R5 showed a lesser extent of raised lesions than in group P. Cholesterol content was lower (P < .05) in all four arterial segments in group R5 than in group P.(ABSTRACT TRUNCATED AT 250 WORDS)

Community screening for diabetes. Low detection rate in a low-risk population.

OBJECTIVE: To evaluate glucose-based community screening for diabetes with regard to detection rate. RESEARCH DESIGN AND METHODS: A retrospective analysis of a community-screening questionnaire data base that included a screening for blood glucose. Referred subjects had fasting glucose levels > 6.4 mM (115 mg/dl) or postprandial levels > or = 8.9 mM (160 mg/dl). An attempt was made to contact referred subjects and to ascertain whether follow-up was undertaken and current status. A random sample of subjects not meeting the glucose criteria (nonreferred) also was contacted in an analogous fashion to referred subjects. RESULTS: In 2,016 questionnaires, glucose-based referral criteria were exhibited by 148 (7.3%) individuals, and subsequent evaluation data were available for 111. Of those 111 individuals, 37 (33%) knew they had diabetes before the screening, and 39 (36%) did not seek further evaluation. Of the remaining 35 subjects, 6 (13%) were told of their new diagnosis of diabetes, and 29 were told they did not have diabetes. Three of 50 nonreferred subjects knew of their diabetes before screening. Thirty percent (14 out of 47) of nonreferred subjects underwent subsequent evaluation, although they were not told to do so. A single new case of diabetes occurred in the nonreferred group. CONCLUSIONS: Community screening for diabetes that is based on measured glucose is of low yield. The known problems of glucose-based screening, coupled with its low yield, make a glucose-based approach difficult to justify. These results indicate that glucose-based community screening should be done only under the careful supervision of a health professional who is trained both in glucose measurement instrumentation and in screening.

Nephrosclerosis, glycohemoglobin, cholesterol, and smoking in subjects dying of coronary heart disease.

Subjects dying of coronary heart disease (CHD) were compared with subjects in a control (basal) group in two series of forensic autopsies. Serum cholesterol assessed in postmortem heart blood was significantly greater in the CHD than in the basal group. CHD subjects were smokers more often than basal subjects, as determined from postmortem serum thiocyanate levels, but the statistical significance is ambiguous (P < 0.06). After exclusion of overt diabetics, a stepwise increase in the percentage of subjects with CHD was observed throughout the normal range for glycohemoglobin. Fibroplasia of small renal arteries, the most reliable postmortem proxy for hypertension, did not differ between CHD and basal groups. These results suggest that young (mean age 49.2 yr) black and white men and women classified from autopsy findings as having CHD as cause of death are often not hypertensive, but instead tend to be hyperlipidemic and glucose intolerant. A surprising result was that arteriolar hyalinization and arterial fibroplasia of the renal cortex often failed to parallel each other between groups of subjects. This was true in comparisons between black and white, male and female, blood cholesterol and glycohemoglobin groupings, and between CHD and basal subjects. This outcome suggests that hyalinization of renal arterioles is an especially reliable marker for CHD and that this association may not be mediated entirely through high blood pressure.

Variability of human coronary artery geometry: an angiographic study of the left anterior descending arteries of 30 autopsy hearts.

A computer-based system is described to measure objectively the geometric parameters of arteries from pairs of projection angiograms. This technique, which employs back-projection to define the vessel axes in 3-D space, was used to obtain selected parameters of coronary artery geometry from radiographic images of autopsy hearts. Results of the first 30 cases are presented, focussing on the distribution of the geometric parameters of the left anterior descending coronary artery (LAD) and its first two major branches. The derived parameters include the angle between the left circumflex artery and the LAD; the angles between the LAD and its early diagonal and septal perforator branches; distances between branch points; and tortuosity. The geometric parameters vary considerably, presumably contributing to a corresponding variability in local hemodynamic and mechanical stresses. Most parameters are uncorrelated. One exception is the angle at the origin of the second diagonal branch, which is positively correlated (p < 0.01) with the distance between the ostia of the first two diagonal vessels; this correlation could reflect the existence of "target" perfusion regions. No relation between geometric parameters and age or gender was seen. In this sample, blacks had a larger angle at the left main bifurcation than whites (p < 0.05).

The relation of atherosclerotic lesions to antemortem and postmortem lipid levels: the Bogalusa Heart Study.

Although postmortem lipid levels have been used as surrogates for levels during life, it is uncertain whether atherosclerotic lesions are related similarly to antemortem and postmortem lipid values. In a sample of 23 children and young adults who had been examined for cardiovascular disease risk factors and subsequently died from violent causes, we examined the relation of (a) postmortem lipid levels to values obtained 1 to 14 years earlier, and (b) atherosclerotic lesions to antemortem and postmortem lipid levels. Postmortem levels of triglycerides and very-low-density lipoprotein cholesterol (VLDLC) were higher than levels during life, but postmortem levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDLC) and high-density lipoprotein cholesterol (HDLC) were related to antemortem levels (rs > 0.40). After excluding eight persons who likely received large volumes of intravenous fluids before death, the within-person variability between antemortem and postmortem levels of LDLC and HDLC was similar to the antemortem variability. Furthermore, the relation of atherosclerotic lesions to antemortem and postmortem lipid levels differed only slightly for TC, LDLC and HDLC. In contrast, lesions in the coronary arteries showed the strongest association with antemortem VLDLC levels, but were not associated with postmortem VLDLC levels. Despite the very small number of subjects, our results suggest that if intravenous fluids are not administered before death, postmortem levels of TC, LDLC and HDLC are fairly representative of levels during life. Postmortem levels of VLDLC or triglycerides, however, should not be used as surrogates for antemortem levels.

Atherosclerosis in Alaska Natives and non-natives.

Low mortality from coronary heart disease (CHD) among Eskimos has been attributed to less atherosclerosis in the coronary arteries because of a high dietary intake of omega-3 fatty acids. Other investigators attribute this low mortality to the fact that Eskimos have a high mortality from other causes before middle age, when CHD is common. However, most studies have been epidemiological, either by death-certificate review or risk-factor evaluation. We evaluated the extent of atherosclerotic lesions in the coronary arteries and aortas from Alaska Natives. Standardised comparisons between samples from 103 Native and 101 non-native residents show that the extent of raised lesions increases with age in both groups, but the prevalence of raised lesions in native specimens was consistently lower than in those from non-natives. This difference was statistically significant. The data suggest that the differences in CHD mortality between Alaska Natives and non-natives are, at least in part, the result of less atherosclerosis in natives.