Trends in the incidence of coronary heart disease and stroke and their risk factors in Japan, 1964 to 2003: the Akita-Osaka study

Prospective care of heart failure in Japan: lessons from CHART studies

There are approximately 23 million patients with heart failure (HF) worldwide. The prognosis of patients with HF is still poor and a prospective approach for preventing and treating HF is necessary. The number of HF patients in Japan has been increasing since 1950 mainly because of a rapidly aging population. Furthermore, westernized dietary pattern, reduced physical activity, and obesity have become prominent, particularly in younger Japanese men. There is an increasing trend of diabetes and dyslipidemia, and the prevalence of smoking and hypertension continues to remain high. One of the largest HF cohorts in Japan, the CHART Studies, showed that coronary artery disease (CAD) was the most frequent etiology of HF currently. Thus, prospective strategies including accurate risk stratification, effective prevention of disease progression through evidence-based treatments, optimally personalized treatment particularly in elderly individuals, and life-long control of CAD risk factors are required to manage HF in Japan.

Low incidence of cardiovascular events in Japanese patients with Type 2 diabetes in primary care settings: a prospective cohort study (JDDM 20)

AIMS

To investigate whether a reduced incidence of cardiovascular disease in Type 2 diabetes can be achieved in a newly recruited cohort following the recently advanced concept of multifactorial treatment and followed in primary care settings as compared with earlier cohorts.

METHODS

A prospective study was performed in primary care settings at multiple clinics nationwide in the Japan Diabetes Clinical Data Management (JDDM) study group. Subjects were 2984 patients with Type 2 diabetes without prevalent cardiovascular disease. The main outcome measure was the first event of non-fatal or fatal coronary heart disease, ischaemic stroke or peripheral artery disease, and the incidence was compared with other representative cohorts.

RESULTS

There were 90 cardiovascular events over 10,827 person-years of follow-up with a dropout rate of 6%. The incidences (per 1000 person-years, 95% confidence interval) of composite, coronary heart disease, ischaemic stroke and peripheral artery disease in the JDDM study were 8.3 (6.6-10.0), 4.4 (3.2-5.6), 3.1 (2.1-4.2), and 0.7 (0.2-1.2), respectively. Each incidence was lowest in the JDDM study compared with other cohorts (P < 0.01 vs. each cohort). In the JDDM study, significant variables predictive of the occurrence of a cardiovascular event were age, duration of diabetes, HbA(1c), HDL cholesterol and urinary albumin.

CONCLUSION

The novel finding of low cardiovascular disease occurrence in this study may be conferred by the feasibility at primary care settings for providing patients with Type 2 diabetes with favourable control of blood glucose, blood pressure and lipids, coupled with unique ethnicity/country factors.

Residual lifetime risk of cardiovascular diseases in Japan

Risk assessment of cardiovascular diseases (CVD) is shifting from the relative risk to an absolute risk approach. The residual lifetime risk (LTR), which provides an absolute risk assessment, is an epidemiologic measure that expresses the probability of someone of a given age and sex developing a disease condition during their remaining lifespan. The LTR estimation is important because it could be more easily comprehended by clinicians and patients. The LTR for CVD was not estimated for the Japanese population until recently, when the LTR of stroke and acute myocardial infarction (AMI) was reported. The reported LTR of stroke and AMI for middle-aged adults is substantial. The observed probabilities illustrated that approximately 1 in 5 men and women of middle age will suffer from a stroke in their remaining lifetime. On the other hand, approximately 1 in 6 men and 1 in 9 women of middle age will suffer from AMI in their remaining lifetime. Aaginst the backdrop of the aging population and worsening risk factor scenario, these estimates re-emphasize that CVD is a public health burden that requires preventive interventions. These estimates provide a means to communicate the absolute risk of CVD to the lay population, policy makers, as well as health service providers in predicting the disease burden of CVD. This easily comprehended knowledge can be used as an important index to assist in public health education and planning.

Adiposity and risk of cardiovascular diseases in Japan: secular trend, individual level associations and causal pathway - implications for the prevention of cardiovascular diseases in societies with rapid economic development

In Japan, overweight/obesity in adults defined as a body mass index of 25 kg/m² or over has roughly doubled among middle-aged men over the past few decades. In parallel with a population rightward shift in the degree of obesity, the proportion of hypertension attributed to overweight has increased. There is an indication that the incidence of ischemic stroke and coronary heart disease remains stable or has been increasing among men. These facts indicate that the relative importance of cardiovascular diseases (CVD) risk factors may have changed. Although it was confirmed at an individual level that the degree of obesity was positively associated with CVD incidence, there is a sizeable proportion of individuals who are at an increased CVD risk state without being overweight/obese in today’s Japan. Thus, further implementation and promotion of activities are needed to bring about meaningful changes in the obesity trend in communities that are harmonized with other domains of CVD prevention activities.

A Japanese health success story: trends in cardiovascular diseases, their risk factors, and the contribution of public health and personalized approaches

There has been a substantial decline in mortality from stroke and ischemic heart disease (IHD) in Japan between the 1960s and 2000s, which contributed to placing Japanese at the top of world’s life expectancy rankings. That mortality decline was attributable to reductions of blood pressure and smoking, in spite of increases in dyslipidemia and diabetes mellitus. The combination of public health and personalized treatment activities to enhance sodium reduction, balanced diets, smoking prevention/cessation as well as hypertension detection and treatment have contributed to the reduction of cardiovascular diseases, demonstrated by a community-based stroke prevention program. The health success story, however, contains an underlying concern about future health threats, the plateaued IHD mortality decline and increased IHD incidence among urban middle-aged men, probably due to increased dyslipidemia and diabetes. The IHD incidence and mortality trends need to be monitored because of a potential future problem for predictive, preventive and personalized medicine.

Lifestyle and cardiovascular disease in Japan

The aim was to give on overview of the profile of cardiovascular disease, vascular pathology and the relationships between lifestyle and cardiovascular disease in Japanese. Compared with the United States and Europe, the higher mortality from stroke and lower mortality from coronary heart disease constitute a unique cardiovascular profile for Japan. A selective review of population-based pathology, trend and prospective cohort studies was performed to clarify the characteristics of cardiovascular disease and vascular pathology, trends in the incidence and mortality of cardiovascular disease, and the relationships between lifestyle and cardiovascular disease among Japanese adults. Since the 1970s, mortality from coronary heart disease as well as stroke has declined substantially in Japan, probably due to a major decline in blood pressure levels and for men a more recent decline in smoking, in spite of an increase in body mass index and total cholesterol levels. However, the decline in mortality was smaller and plateaued in middle-aged men aged 30-49 in the metropolitan cities of Tokyo and Osaka. The incidence of coronary heart disease has increased among middle-aged men residing in the suburbs of Osaka. As for the associations between lifestyle and cardiovascular disease, higher sodium, lower calcium and lower animal protein content in the diet and for men higher alcohol consumption may account for the higher prevalence of hypertension and higher risk of stroke for Japanese than for western populations. On the other hand, lower saturated fat (meat) and higher n3 polyunsaturated fat (fish) in the Japanese diet may contribute to the lower prevalence of hypercholesterolemia and lower risk of coronary heart disease among Japanese. Japan is unique among developed countries in that coronary heart disease mortality has been low and has continued to decline, while stroke mortality has declined substantially. However, a recent trend for coronary heart disease incidence to increase among urban men is a cause for concern as a potential source of future problems for public health and clinical practice in Japan.

[Cholesterol controversy: cutoff point of low-density lipoprotein cholesterol level in Guidelines by Japan Atherosclerosis Society]

In 2007, the Japan Atherosclerosis Society published the Guidelines for prevention of atherosclerotic cardiovascular diseases. However, the guidelines have several flaws with regard to the cutoff level of serum low-density lipoprotein cholesterol (LDL-C). First, LDL-C level is used instead of serum total cholesterol (TC) level in the guidelines. In this case, they must show at least some basic data on the relationship between LDL-C level and mortality or morbidity from coronary heart disease (CHD). Second, it was recommended that the LDL-C level be below 140 mg/dL or 3.6 mmol/L (corresponding to a TC level of 220 mg/dL or 5.7 mmol/L, respectively). These levels are unreasonable considering that the TC levels of 240-260 mg/dL are optimal in terms of all-cause mortality for the Japanese population. Third, although there are big differences in mortality and morbidity from CHD between sexes, they discussed the matter without considering these differences. Last but not least, the conflict of interest of the editors of the guidelines has never been disclosed. The Japanese population has a lower CHD mortality and incidence than populations from other industrialized countries despite an increase in serum TC level in the former. In populations with a markedly lower coronary mortality or morbidity such as the Japanese population, it is still important to determine the optimal cutoff level of LDL-C to prevent the development of CHD and other atherosclerotic diseases.

Ten-year evaluation of homogeneous low-density lipoprotein cholesterol methods developed by Japanese manufacturers. Application of the Centers for Disease Control and Prevention/Cholesterol Reference Method Laboratory Network lipid standardization protocol

AIM

The risk index for atherosclerotic cardiovascular diseases in the Japanese metabolic syndrome-focused health checkup program was changed from total cholesterol (TC) to low-density lipoprotein cholesterol (LDL-C). We discuss the validity of this change with respect to standardization.

METHODS

The beta-quantification procedure of the Centers for Disease Control and Prevention (CDC) uses the LDL-C reference value as a target. Clinical laboratories and commercial manufacturers use homogeneous LDL-C methods for standardization. (A) For clinical laboratories, LDL-C in 648 samples requested from 108 hospitals was analyzed. (B) Manufacturers participated in the CDC/Cholesterol Reference Method Laboratory Network LDL-C standardization protocol. The standardization was conducted with a performance follow-up for the 10-year period from 1998 to 2008 at 2-year intervals, 6 times.

RESULTS

(A) In clinical laboratories, acceptable LDL-C levels within ±4% of the CDC's criteria remained 70.4%, 456 of 648 subjects. Negative maximum bias deviating from the LDL-C target value was -35.8%, -52.5 mg/dL, and positive maximum bias was +24.5%, +32.3 mg/dL. (B) For manufacturers, the standardization achievement rate of the analytical reagent/instrument/calibrator system in the last four standardizations from 2002 to 2008 remained on average 66.6%, far lower than the level required.

CONCLUSIONS

The standardization achievement rate of homogeneous LDL-C methods was much low-er than that of TC. TC should still be used as a risk index for atherosclerotic cardiovascular diseases. The standardization achievement rate of homogeneous LDL-C should be maintained at 100%, at least using samples with normal lipoprotein profiles. The accuracy and specificity of LDL-C should be further improved before practical and clinical use.

Body Mass Index and Risk of Stroke and Myocardial Infarction in a Relatively Lean Population

Background–

The association of overweight/obesity with the incidence of cardiovascular diseases, especially stroke, has not been comprehensively examined in relatively lean populations in which stroke is more prevalent than coronary heart disease.

Methods and Results–

Pooled individual data from 16 Japanese cohorts comprising 45 235 participants ages 40 to 89 years without previous history of cardiovascular disease were studied. During follow-up, 1113 incident strokes and 190 myocardial infarctions were identified. At baseline, mean ages of men and women were 55.4 and 56.5 years and mean body mass indices (BMI) were 23.0 and 23.4 kg/m 2 , respectively. Compared with those with BMI <21.0, incidence rates of cerebral infarction in subjects with BMI ≥27.5 were significantly elevated in both men (hazard ratio, 1.81; 95% confidence interval [CI], 1.28 to 2.56) and women (hazard ratio, 1.65; 95% CI, 1.23 to 2.21), adjusted for age, smoking, and drinking habit. Incidence of cerebral hemorrhage was also associated positively with BMI in both men (hazard ratio, 2.51; 95% CI, 1.21 to 5.20) and women (hazard ratio, 1.98; 95% CI, 1.12 to 3.52). Adjustment for systolic blood pressure, a mediating factor, significantly attenuated most BMI association with stroke in both sexes. For myocardial infarction, the hazard ratio was 3.16 (95% CI, 1.66 to 6.01) for BMI 27.5 or greater versus less than 21.0 only in men, which appeared partly mediated by total cholesterol and SBP.

Conclusions–

Overweight/obesity was associated with an increased risk of cerebral infarction and hemorrhage in men and women and myocardial infarction in men. Weight control may have the potential to prevent both stroke and myocardial infarction in Japan.

Iron intake and associated factors in general Japanese population: NIPPON DATA80, NIPPON DATA90 and national nutrition monitoring

OBJECTIVE

The purpose of this study was to investigate the dietary iron intake and associated other dietary factors and clinical characteristics among a representative sample cohort of Japanese population.

METHODS

We obtained data from NIPPON DATA80 and 90 that were conducted with the National Nutrition Surveys in 1980 and in 1990. Then we estimated nutrient and food intakes of individuals in the National Nutrition Survey of 1980 and that of 1990, which were adjusted on the basis of data of the National Nutrition Survey of 1995. Finally, we analyzed data for the 10,422 participants (4585 men and 5837 women) in NIPPON DATA80 and 8342 participants (3488 men and 4854 women) in NIPPON DATA90 having dietary iron intake information.

RESULTS

In NIPPON DATA80 and 90, there was a significant relationship between the dietary iron intake and age for both men and women. Dietary protein intake was associated with iron intake where as dietary fat intake did not show any association. Regarding the minerals, significant relationships were observed between the different minerals and dietary iron intake. Apart from the food group of milk and dairy products, there were significant differences in other food groups according to quintiles of iron intakes for men and women.

CONCLUSIONS

We described the mean dietary iron intake and its relation with other dietary factors and clinical characteristics in Japanese adults as the baseline data in NIPPON DATA80 and in NIPPON DATA90.

Psychological distress and cardiovascular disease: the Circulatory Risk in Communities Study (CIRCS)

Although a number of epidemiological studies have reported that psychological factors are associated with increased risk of cardiovascular morbidity and mortality, the relevant epidemiological data are mostly limited to Western populations. The present study sought to examine associations of depressive symptoms, anger expression, and tension with the incidence of cardiovascular disease in the Circulatory Risk in Communities Study (CIRCS). Depressive symptoms were measured in 901 men and women by using the Zung Self-Rating Depression Scale (SDS); anger expression and tension were measured in 6292 men and women by using the Anger Expression Scale and Framingham Tension Scale. As compared with the participants with SDS scores in the lowest tertile, those with scores in the highest tertile had twice the age- and sex-adjusted hazard ratio of total stroke. However, this excess risk was present only for ischemic stroke. Participants in the highest tertile also had a 7-fold adjusted hazard ratio of coronary heart disease, as compared with those in the lowest tertile. These associations were virtually unchanged after further adjustment for covariates. Men with “anger-in” scores in the highest tertile had a 1.5-fold age-adjusted relative risk of hypertension as compared with those in the lowest tertile; anger-in score was not associated with hypertension in women. In men and women, there were no associations between hypertension and either “anger-out” or tension scores. These findings generally support the hypothesis that—as is the case in Western populations—anger suppression and depression increase the risk of cardiovascular disease among Japanese.

Polyunsaturated fatty acid levels of serum and red blood cells in apparently healthy Japanese subjects living in an urban area

AIM

We assessed levels of polyunsaturated fatty acid (PUFA) in serum and red blood cells (RBCs) among groups stratified by generation and its clinical significance in Japanese subjects living in an urban area.

METHODS

We enrolled 200 apparently healthy Japanese (126 males, mean age: 50.3+/-9.2 years) living in an urban area. Levels of PUFA, including eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), arachidonic acid (AA), and dihomo-gamma-linolenic acid (DGLA) in serum and RBCs were measured for each generation (G1 <35y, G2 35y-<45y, G3 45y-<55y, G4 55y-<65y, G5>or=65y).

RESULTS

No significant differences in EPA, DHA, AA, or EPA/AA were observed between males and females. After dividing into generations, stepwise increases in EPA and DHA, but not DGLA or AA, were observed in serum (all p<0.0001). EPA/AA ratios were stepwisely increased in serum (mean: G1:0.26, G2:0.29, G3:0.43, G4:0.58, G5:0.68, p<0.0001) and RBCs (mean: G1:0.10, G2:0.09, G3:0.15, G4:0.20, G5:0.23, p<0.0001). Positive correlations of EPA (r=0.83), DHA (r=0.55), DGLA (r=0.54), AA (r=0.29), and EPA/AA (r=0.91) were demonstrated between serum and RBCs. In addition, a significant positive correlation between EPA/AA ratios and insulin sensitivity as well as a negative correlation between those ratios and insulin resistance were observed in subjects with metabolic syndrome.

CONCLUSION

Low levels of EPA/AA, which were associated with insulin resistance, were demonstrated in young Japanese adults living in an urban area.

Novel therapeutic concepts: the epidemic of cardiovascular disease in the developing world: global implications

The epidemic of cardiovascular disease (CVD) is a global phenomenon, and the magnitude of its increase in incidence and prevalence in low- and middle-income countries (LIMIC) has potentially major implications for those high-income countries that characterize much of the developed world. Cardiovascular disease remains the leading cause of death in the world and approximately 80% of all cardiovascular-related deaths occur in LIMIC and at a younger age in comparison to high-income countries. The economic impact in regard to loss of productive years of life and the need to divert scarce resources to tertiary care is substantial. The 'epidemiologic transition' provides a useful framework for understanding changes in the patterns of disease as a result of societal and socioeconomic developments in different countries and regions of the world. A burning but as yet unanswered question is whether gains made over the last four decades in reducing cardiovascular mortality in high-income countries will be offset by changes in risk factor profiles, and in particular obesity and diabetes. Much of the population attributable risk of myocardial infarction is accountable on the basis of nine modifiable traditional risk factors, irrespective of geography. Developing societies are faced with a hostile cardiovascular environment, characterized by changes in diet, exercise, the effects of tobacco, socioeconomic stressors, and economic constraints at both the national and personal level in addition to exposure to potential novel risk factors and perhaps a genetic or programmed foetal vulnerability to CVD in later life. There are major challenges for primary and secondary prevention including lack of data, limited national resources, and the lack of prediction models in certain populations. There are two major approaches to prevention: public health/community-based strategies and clinic-based with a targeted approach to high-risk patients and combinations of these. There are concerns that in comparison with communicable diseases, cardiovascular and chronic diseases have a relatively low priority in the global health agenda and that this requires additional emphasis. The human race has had long experience and a fine tradition in surviving adversity, but we now face a task for which we have little experience, the task of surviving prosperity Alan Gregg 1890-1957, Rockefeller Foundation.

Occupational class and incidence rates of cardiovascular events in middle aged men in Japan

We investigated whether occupational class affects the incidence of cardiovascular events in Japanese factory workers. We prospectively evaluated 1,794 male workers aged 40-59, including 632 non-manual and 1,162 manual workers, employed in a metal products factory in Japan. The hazard ratios of stroke, myocardial infarction (MI) and cardiovascular events (combined stroke, MI and sudden cardiac death) for manual workers were compared with non-manual workers as estimated by the Cox proportional hazards regression model. Among the 1,794 workers, there were 60 cardiovascular events (32 cases of stroke, 23 cases of MI and 5 cases of sudden cardiac death) with an incidence rate of 3.14 per 1,000 person-years for cardiovascular events; 1.68 for stroke and 1.20 for MI. Blood pressure and HbA1c significantly increased the risk of stroke. Body mass index and total cholesterol significantly increased the risk of MI. However, occupational class was determined not to be a risk factor for cardiovascular events. The hazard ratios of stroke, MI and cardiovascular events for manual workers compared with non-manual workers were 0.97 (95%CI, 0.45-2.08), 0.73 (95%CI, 0.30-1.79) and 0.92 (95%CI, 0.53-1.61), respectively. Our study did not reveal significant occupational class inequalities in the rate of cardiovascular events. These findings are not in accordance with studies from other industrialized countries.

Relations between protein intake and blood pressure in Japanese men and women: the Circulatory Risk in Communities Study (CIRCS)

BACKGROUND

An inverse association between protein intake and blood pressure has been reported in Western countries. However, the evidence is limited for Asians, whose protein sources are different from those in Western populations.

OBJECTIVES

The objective was to examine the association between protein intake and blood pressure in Japanese adults.

METHODS

We conducted a population-based, cross-sectional study of 7585 subjects (3499 men and 4086 women) from 40 to 69 y of age living in 5 communities in Japan. Dietary intakes of total, animal, and plant protein were estimated by a single 24-h dietary recall. We then examined the associations between dietary intake of those proteins and blood pressure after adjustment for age, sex, community, body mass index, antihypertensive medication use, ethanol intake, smoking, and dietary intakes of sodium, potassium, and calcium.

RESULTS

After adjustment for cardiovascular disease risk factors, a 25.5-g/d increment in total protein intake was associated with a decrease in systolic blood pressure of 1.14 mm Hg (P < 0.001) and in diastolic blood pressure of 0.65 mm Hg (P < 0.001), and a 19.9-g/d increment in animal protein intake was associated with a decrease in systolic blood pressure of 1.09 mm Hg (P < 0.001) and in diastolic blood pressure of 0.41 mm Hg (P = 0.003). A 13.1-g/d increment in plant protein intake was associated with a decrease in diastolic blood pressure of 0.57 mm Hg (P < 0.001). Further adjustment for nutritional factors weakened these associations, but the inverse associations of total protein intake with diastolic blood pressure and of animal protein intake with systolic blood pressure remained statistically significant.

CONCLUSION

Total and animal protein intakes were inversely associated with blood pressure in Japanese adults.

High-normal blood pressure and the risk of cardiovascular disease

The guidelines of the Joint National Committee 7 from the USA on hypertension have unified the normal and high-normal blood pressure categories into a single entity termed ;prehypertension'. In contrast, The European Guidelines for the management of hypertension in 2007 considered ;prehypertensive' to be divided into normal and high-normal blood pressure. These patients with high-normal blood pressure or prehypertension might progress to hypertension over time. Previous studies have shown that high-normal blood pressure is a risk factor for cardiovascular disease (CVD) in Western countries and Japan. The combination of high-normal blood pressure and other cardiovascular risk factors increases the risks of CVD. Recently, metabolic syndrome has also been shown to be a risk factor for CVD. In Japan, the association between metabolic syndrome and CVD was also found to be significant. The risks for CVD incidence were similar among participants who had the same number of components, regardless of the presence of abdominal obesity. In the Japanese guidelines for the management of hypertension published in 2009, patients are considered to be in a high-risk group if they have diabetes, chronic kidney disease, 3 or more risk factors, target organ damage or CVD, even if they have only high-normal blood pressure, and appropriate antihypertensive therapy should be initiated.

Prevalence and causes of early-onset dementia in Japan: a population-based study

BACKGROUND AND PURPOSE

Few studies are available that have addressed the prevalence of early-onset dementia (EOD), including early-onset Alzheimer disease and other forms of dementia in Japan.

METHODS

A 2-step postal survey was sent to all of the 2475 institutions providing medical or care services for individuals with dementia in Japan's Ibaraki prefecture (population, 2 966 000) requesting information on EOD cases. Data were then reviewed and collated.

RESULTS

We identified 617 subjects with EOD. The estimated prevalence of EOD in the target population was 42.3 per 100 000 (95% CI, 39.4 to 45.4). Of the illnesses that cause EOD, vascular dementia was the most frequent (42.5%) followed by Alzheimer disease (25.6%), head trauma (7.1%), dementia with Lewy bodies/Parkinson disease with dementia (6.2%), frontotemporal lobar degeneration (2.6%), and other causes (16.0%).

CONCLUSIONS

The prevalence of EOD in Japan appeared to be similar to that in Western countries with the notable exception that vascular dementia was the most frequent cause of EOD in Japan.

Trends for blood pressure and its contribution to stroke incidence in the middle-aged Japanese population: the Circulatory Risk in Communities Study (CIRCS)

BACKGROUND AND PURPOSE

Hypertension is a major risk factor for stroke. However, a substantial decrease in blood pressure levels in Japanese during the past 3 decades may have reduced contributions of hypertension to risk of stroke. The population attributable fraction, the percentage of outcomes attributable to exposure, of blood pressure for the incidence of stroke was investigated during 3 survey periods between 1963 and 1994 by means of a population-based cohort study.

METHODS

We explored 3 cohort data of residents aged 40 to 69 years in 4 Japanese communities in 1963 to 1971 (n=5439), 1975 to 1984 (n=9945), and 1985 to 1994 (n=11 788) baseline surveys. Mean follow-up period for each cohort was 10 years.

RESULTS

Higher blood pressure levels were associated with higher risk of stroke. Positive associations were also observed even within nonhypertension levels. From the first to the third cohorts, the blood pressure category with a majority of stroke incidence shifted from severe or moderate hypertension to mild hypertension. The population attributable fraction of the severe hypertension category in the first, second, and third cohorts were 20%, 14%, and 9%, respectively, and those of the moderate hypertension category were 19%, 24%, and 11%, respectively, whereas those of the mild hypertension category were 17%, 26%, and 23%, respectively. The results were similar when participants on antihypertensive medication were excluded.

CONCLUSIONS

The higher risk of stroke incidence with higher blood pressure levels even in nonhypertension categories and the shift of stroke burden from severe/moderate hypertension to mild hypertension support the early management of hypertension and primary prevention of high blood pressures for the prevention of stroke.

Coronary spasm preferentially occurs at branch points: an angiographic comparison with atherosclerotic plaque

BACKGROUND

Coronary spasm plays an important role in the pathogenesis of ischemic heart disease. However, similarities and differences between coronary spasm and atherosclerosis are not known. We examined the angiographic characteristics of coronary spasm in comparison with those of atherosclerosis.

METHODS AND RESULTS

Thirty-two left anterior descending arteries, 11 left circumflex arteries, and 23 right coronary arteries with spasm and atherosclerotic plaque were analyzed for the localization of spasm in comparison with that of plaque in 47 patients (38 men and 9 women, mean age 66.8+/-10.3 yrs). Spasm predominantly occurred at the branch point as compared with plaque in each of the 3 arteries (76.7% versus 23.3%, P<0.0001; 72.7% versus 9.1%, P<0.039; and 60.0% versus 10.0%, P=0.002, in the left anterior descending, left circumflex, and right coronary arteries, respectively). Spasm involved the proximal segment less frequently as compared with plaque in each of the 3 arteries (56.7% versus 93.3%, P<0.0001; 18.2% versus 81.8%, P=0.016; and 15.0% versus 75.0%, P<0.0001 in the left anterior descending, left circumflex, and right coronary arteries, respectively). Most spasms occurred at the nonplaque site in each of the 3 arteries (73.3%, P=0.018; 100%, P<0.0001; and 75.0%, P=0.041 in the left anterior descending, left circumflex, and right coronary arteries, respectively).

CONCLUSIONS

Coronary spasm preferentially occurred at branch points and nonplaque sites, whereas the atherosclerotic lesion was predominantly localized at the nonbranch points of the curved proximal segments. Coronary spasm may thus be a manifestation of a distinct type of arteriosclerosis different from the lipid-laden coronary atherosclerosis.