Editorial
Practical Cutoff Values of Brachial–Ankle Pulse Wave Velocity to Predict 10-Year CHD Risk in the Japanese General Population
2023 Volume 30 Issue 5 Pages 437-439
Details
2023 Volume 30 Issue 5 Pages 437-439
See article vol. 30: 481-490
Coronary heart disease (CHD) is one of the major causes of death and disability in developed countries. Early detection of and adequate intervention in individuals with high CHD risk are important to save medical cost and achieve a healthy aging society.
The Framingham risk score (FRS) is one of the major models used for predicting the 10-year risk of developing CHD1). This score uses age, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), blood pressure (BP), diabetes, and smoking status to estimate the risk for CHD over 10 years based on the Framingham data including individuals aged 30–74 years. However, it has been reported that the use of FRS resulted in an overestimation of CHD risk in some populations. This is also true in the Japanese population, which constitutes a unique aspect in terms of cardiovascular disease risk with a markedly lower incidence of CHD and higher incidence of stroke compared with Western populations2). In Japan, the Suita score has been developed as a risk score for predicting the 10-year risk for the development of CHD in Japanese participants aged 35–79 years and derived from a mean follow-up of 11.8 years of the Suita cohort3). The score is calculated based on age, sex, LDL-C, HDL-C, diabetes, BP, smoking habits, and estimated glomerular filtration rate. It has been shown in the Suita cohort that FRS significantly overestimates the actual 10-year risk of cardiac events over the broad risk level3). The poor predictability of FRS for CHD incidence in the Japanese population would be due mainly to the following two reasons. First, the crude incidence rate of CHD in the original Framingham cohort was nearly three times higher than that in the Suita cohort (8.94 per 1000 person-years vs. 2.81 per 1000 person-years). Second, the risk of hypertension, low HDL-C for men, and diabetes and smoking for women were found to be higher in the Suita cohort than the risk in the Framingham cohort3). Therefore, the risk of CHD should be examined using the Suita score instead of the FRS in the Japanese population.
Arterial stiffness assessed using pulse wave velocity (PWV) is now well recognized as an independent predictor of cardiovascular events. Carotid–femoral PWV is a gold standard for PWV but brachial–ankle PWV has been used in general practice in Japan4). Recent meta-analyses that included several Japanese cohorts have shown that the predictability of cardiovascular events using brachial–ankle PWV is never inferior to that using carotid–femoral PWV5, 6). The use of brachial–ankle PWV is now spreading in East Asian countries4). However, the data on whether brachial–ankle PWV could purely predict onset of cardiac events is lacking because in most studies, the primary endpoints comprised brain and heart diseases. Moreover, cardiac events included, in many cases, both onset and death. Thus, it remains unclear whether brachial–ankle PWV can predict CHD onset in the Japanese population. One possible method to address this issue is to compare brachial–ankle PWV with a valid predictive marker of CHD onset. Yamashina et al. examined the relationship between brachial–ankle PWV and FRS in 10,828 subjects who underwent annual health checkup examinations and showed that a brachial–ankle PWV ＞1,400 cm/s is an independent variable for the risk stratification of moderate to high risk categories determined using the FRS7). Until now, however, no study has addressed the relationship between brachial–ankle PWV and the Suita score in the Japanese general population. In this issue of the Journal of Atherosclerosis and Thrombosis, Mori et al. examined for the first time the association between brachial–ankle PWV and the Suita score in a total of 25,602 participants who underwent annual health checkups (57% men) and compared the impact of brachial–ankle PWV using the FRS and Suita score8). Importantly, they tried to obtain the cutoff value of brachial–ankle PWV for CHD risk stratified by sex and age, which is important to apply in daily clinical practice. The Suita score demonstrated better correlations with brachial–ankle PWV than the FRS in both sexes (men, Suita score r=0.613 and FRS r=0.571 and women, Suita score r=0.706 and FRS r=0.557). The better correlation between brachial–ankle PWV and Suita score than the FRS strongly indicates the importance of renal function as a common modulator for arterial stiffness and the onset of CHD in the Japanese population. The ROC curve analysis demonstrated that the cutoff values of brachial–ankle PWV for moderate- and high-risk groups estimated using the Suita score increases with age in men and women with the same value in their 40s and 50s and showed the different values in the 60s and 70s between genders (Fig.1). Thus, the proposal of sex- and age-specific cutoff values is important. The results of this study will help identify individuals at moderate or high risk of CHD during health checkups and will allow early intervention. However, one issue remains to be investigated. The Suita cohort is an urban population, and it remains unclear whether the proposed cutoff values can be broadly applied to the Japanese general population. The crude incidence of AMI in the Japan Morning Surge cohort and the Japan Arteriosclerosis Longitudinal Study cohort, both made up of mainly rural populations, was 0.68 and 0.60 per 1000 person-years, respectively, whereas that in the Suita cohort was 1.40 3). Therefore, further long-term follow-up studies in a global Japanese general population are required to confirm the validity of the proposed cutoff values.
Proposed cutoff values of brachial–ankle PWV for moderate- and high-risk groups by sex and age derived using the Suita score
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