Heterozygous familial hypercholesterolemia (HeFH) is a genetic disorder that elevates low-density lipoprotein cholesterol and increases the risk of premature atherosclerotic cardiovascular disease (ASCVD). However, despite their atherogenic lipid profiles, the cardiovascular risk of HeFH varies in each individual. Their variety of phenotypic features suggests the need for better risk stratification to optimize their therapeutic management. The current review summarizes three potential approaches, including (1) definition of familial hypercholesterolemia (FH)-related risk scores, (2) genetic analysis, and (3) biomarkers. The International Atherosclerosis Society has recently proposed a definition of severe FH to identify very high-risk HeFH subjects according to their clinical characteristics. Furthermore, published studies have shown the association of FH-related genetic phenotypes with ASCVD, which indicates the genetic analysis’s potential to evaluate individual cardiovascular risks. Biomarkers reflecting disease activity have been considered to predict the formation of atherosclerosis and the occurrence of ASCVD in HeFH subjects. Incorporating these risk stratifications will be expected to allocate adequate intensity of lipid-lowering therapies in HeFH subjects, which ultimately improves cardiovascular outcomes.

Aim: The 2017 Japan Atherosclerosis Society (JAS) familial hypercholesterolemia (FH) criteria adopt a cut-off value of ≥ 9 mm of Achilles tendon thickness (ATT) detected by X-ray as one of the three key items. This threshold was determined based on an old data evaluating the ATT of 36 non-FH individuals that was published in 1977. Although the specificity of these clinical criteria is extremely high due to a strict threshold, there are a significant number of patients with FH whose ATT ＜9 mm. We aimed to determine a cut-off value of ATT detected by X-ray to differentiate FH and non-FH based on genetic diagnosis.

Methods: The individuals (male/female=486/501) with full assessments of genetic analyses for FH-genes (LDLR and PCSK9), serum lipids, and ATT detected by X-ray at the Kanazawa University Hospital and National Cerebral and Cardiovascular Center Research Institute were included in this study. Receiver operating characteristic (ROC) analyses were conducted to determine a better cut-off value of ATT that predicts the pathogenic mutation of FH.

Results: The ROC analyses revealed that the best cut-off values of ATT are 7.6 mm for male and 7.0 mm for female, with the sensitivities/specificities of 0.83/0.83 for male and 0.86/0.85 for female, respectively. If the thresholds of ATT of 8.0/7.5 mm and 7.5/7.0 mm were applied to the diagnosis of male/female FH, the sensitivities/specificities predicting the pathogenic mutation of FH by the 2017 JAS FH clinical criteria would be 0.82/0.90 and 0.85/0.88, respectively.

Conclusions: These results suggest that the cut-off value of ATT detected by X-ray is obviously lower than 9.0 mm, which was adopted by the 2017 JAS FH clinical criteria.

Aim: Atherosclerosis is responsible for high morbidity and mortality rates around the world. Local arterial oxidative stress is involved in all phases of atherosclerosis development. Mitochondria is a relevant source of the oxidants, particularly under certain risky conditions, such as hypercholesterolemia. The aim of this study was to test whether lowering the production of mitochondrial oxidants by induction of a mild uncoupling can reduce atherosclerosis in hypercholesterolemic LDL receptor knockout mice.

Methods: The mice were chronically treated with very low doses of DNP (2,4-dinitrophenol) and metabolic, inflammatory and redox state markers and atherosclerotic lesion sizes were determined.

Results: The DNP treatment did not change the classical atherosclerotic risk markers, such as plasma lipids, glucose homeostasis, and fat mass, as well as systemic inflammatory markers. However, the DNP treatment diminished the production of mitochondrial oxidants, systemic and tissue oxidative damage markers, peritoneal macrophages and aortic rings oxidants generation. Most importantly, development of spontaneous and diet-induced atherosclerosis (lipid and macrophage content) were significantly decreased in the DNP-treated mice. In vitro, DNP treated peritoneal macrophages showed decreased H₂O₂ production, increased anti-inflammatory cytokines gene expression and secretion, increased phagocytic activity, and decreased LDL-cholesterol uptake.

Conclusions: These findings are a proof of concept that activation of mild mitochondrial uncoupling is sufficient to delay the development of atherosclerosis under the conditions of hypercholesterolemia and oxidative stress. These results promote future approaches targeting mitochondria for the prevention or treatment of atherosclerosis.

Aim: Familial hypercholesterolemia (FH) is an underdiagnosed autosomal dominant genetic disorder characterized by high levels of plasma low-density lipoprotein cholesterol (LDL-C) from birth. This study aimed to assess the genetic identification of FH in children with high LDL-C levels who are identified in a universal pediatric FH screening in Kagawa, Japan.

Method: In 2018 and 2019, 15,665 children aged 9 or 10 years underwent the universal lipid screening as part of the annual health checkups for the prevention of lifestyle-related diseases in the Kagawa prefecture. After excluding secondary hyper-LDL cholesterolemia at the local medical institutions, 67 children with LDL-C levels of ≥ 140 mg/dL underwent genetic testing to detect FH causative mutations at four designated hospitals.

Results: The LDL-C levels of 140 and 180 mg/dL in 15,665 children corresponded to the 96.3 and 99.7 percentile values, respectively. Among 67 children who underwent genetic testing, 41 had FH causative mutations (36 in the LDL-receptor, 4 in proprotein convertase subtilisin/kexin type 9, and 1 in apolipoprotein B). The area under the curve of receiver operating characteristic curve predicting the presence of FH causative mutation by LDL-C level was 0.705, and FH causative mutations were found in all children with LDL-C levels of ≥ 250 mg/dL.

Conclusion: FH causative mutations were confirmed in almost 60% of the referred children, who were identified through the combination of the lipid universal screening as a part of the health checkup system and the exclusion of secondary hyper-LDL cholesterolemia at the local medical institutions.

Aims: In this study, we integrated two randomized control trials, PROSPECTIVE and IMPACT, to address the effect of probucol on cerebrocardiovascular events and carotid intima-media thickness (IMT) in Japanese, Korean, and Chinese patients with coronary artery disease (CAD).

Methods: A total of 1,025 patients from the PROSPECTIVE and IMPACT studies were enrolled. The time to the first major adverse cerebrocardiovascular event, in addition to carotid IMT and lipid levels, was compared between the control and probucol groups.

Results: In the integrated analysis, the adjusted hazard ratio (HR) and 95% confidence interval (CI) were 0.67 and 0.44–1.03, respectively, indicating a tendency to show the effect of probucol on cerebrocardiovascular events in secondary prevention. We also found no significant differences between the control and probucol groups in the mean IMT of the carotid arteries and its changes. However, we found a significant decrease in cerebrocardiovascular events in patients with reduced levels of HDL cholesterol (HDL-C) (≥ 6.25 mg/dL) compared with those with levels ＜6.25 mg/dL (p=0.024), without any increase in adverse events such as severe ventricular arrhythmias.

Conclusion: We demonstrated a marginal effect of probucol on cerebrocardiovascular events in Asian patients with CAD, with reasonable safety profiles. A larger study may be needed to support the effect of probucol for cardiovascular prevention.

Aim: Maintaining functional status through revascularization is a major goal in patients with chronic limb-threatening ischemia (CLTI). Nevertheless, there is a lack of clarity on the impact of revascularization on mobility over time. This study examined ambulatory status over time after revascularization and predictors of ambulation loss in CLTI patients.

Methods: We used a clinical database established by the Surgical reconstruction versus Peripheral INtervention in pAtients with critical limb isCHemia study, a prospective, multicentre, observational study including patients with CLTI. The primary endpoint was mobility over time.

Results: Of the 381 patients, the ambulatory proportion at baseline was 71%. The proportion gradually decreased, finally reaching 40% at 36 months. In non-ambulatory patients at revasacularisation, approximately 20-40% of patients achieved ambulation. Multivariate analysis confirmed that age, impaired mobility before CLTI onset and at revascularization, renal failure on dialysis, and WIfI clinical stage 4 were positively associated with ambulation loss at either specific or all time points, whereas male sex and surgical reconstruction were inversely associated with the outcomes at specific time points.

Conclusion: Mobility in the overall population gradually decreased, whereas the number of deceased patients increased. Advanced age, impaired mobility before CLTI onset and at revascularization, renal failure on dialysis, and WIfI stage 4 were associated with ambulation loss at almost all points after revascularization.

Aim: Improving cholesterol efflux capacity (CEC) of high-density lipoprotein (HDL) has been regarded as a novel target for preventing cardiovascular disease. HDL reportedly has antioxidant properties which may contribute to its functions. We investigated changes in CEC with intake of the Japan Diet (JD) recommended by the Japan Atherosclerosis Society and the relationship of these changes to serum antioxidant concentrations.

Methods: A randomized parallel controlled clinical trial on JD intake was performed in Japanese patients with dyslipidemia. Ninety-eight participants were randomly divided into the JD (n=49) or the partial JD (PJD) (n=49) group. Nutrition education, based on each diet at baseline and at 3 months, was provided and the participants were followed up for 6 months.

Results: Mean CEC was 1.05 in total and correlated positively with HDL-cholesterol (p＜0.001) at baseline. CEC did not change while oxygen radical absorbance capacity (ORAC) was decreased in both groups (p＜0.001). Although serum total carotenoid increased in both groups, serum α-tocopherol decreased in the JD group as compared to the PJD group (p＜0.05). CEC correlated positively with HDL ORAC at baseline (p=0.021) and with serum total carotenoid at 3 and 6 months (p=0.005, 0.035). Changes in CEC correlated positively with changes in HDL ORAC at 3 months and serum total tocopherol at 3 and 6 months (p＜0.001).

Conclusion: CEC was not changed by JD education in Japanese patients with dyslipidemia who already had normal CEC at baseline. CEC was suggested to be positively associated with serum α- and γ-tocopherol and HDL ORAC.

Aim: In this study, we aim to examine the clinical meaning of low-density lipoprotein cholesterol (LDL-C) ＜70 mg/dL as assessed by Friedewald equation [LDL-C (F)] and Martin method [LDL-C (M)] and non-high-density lipoprotein cholesterol (HDL-C) ＜100 mg/dL on the occurrence of new lesions among Japanese patients with stable angina who underwent percutaneous coronary intervention (PCI) and were prescribed with strong statins.

Methods: Among the 537 consecutive stable angina patients who had underwent PCI and had been prescribed with strong statins, the association between the occurrence of new lesions with myocardial ischemia at the 9-month follow-up coronary angiography and ≤ 2 years after PCI and baseline characteristics were assessed.

Results: New lesions appeared 9 months and ≤ 2 years after PCI in 31 and 90 patients, respectively. Multivariate logistic regression analysis revealed diabetes mellitus (DM) was significantly associated with the occurrence of new lesions ≤ 2 years after PCI [odds ratio (OR) 1.71, 95 % confidence interval (CI) 1.06–2.83, p=0.031], and only non-HDL-C ≥ 100 mg/dL was associated with the occurrence of new lesions both at 9 months and ≤ 2 years after PCI [OR 1.80, 95 % CI 1.10–3.00, p=0.021 and OR 1.85, 95 % CI 1.13–3.07, p=0.016].

Conclusions: Non-HDL-C ≥ 100 mg/dL was determined to be the independent risk factor for the occurrence of new lesions 9 months and ≤ 2 years after PCI among stable angina patients with strong statins. Residual risk after PCI should be considered by assessing not only DM but also non-HDL-C beyond the scope of LDL-C-lowering therapy with strong statins.

Aims: Familial hypercholesterolemia (FH) is characterized by high low-density lipoprotein (LDL) cholesterol levels, xanthomas including Achilles tendon thickening, and premature coronary artery disease (CAD). Carotid intima-media thickness (IMT) is a well-established surrogate marker for CAD in FH and Achilles tendon thickening is a specific physical finding in patients with FH. The objective of the present study was to identify factors associated with carotid IMT and Achilles tendon thickness in FH heterozygotes on lipid-lowering therapy. This study also aimed to examine the follow-up changes in carotid IMT and Achilles tendon thickness among them in the current real-world FH practice.

Methods: The current study is a subanalysis of the Familial Hypercholesterolemia Expert Forum (FAME) Study. The severity of carotid atherosclerosis was assessed with the maximal and mean IMT using ultrasonography, and Achilles tendon thickness was measured using X-rays. The present study used 571 patients under medical treatment for heterozygous FH who had baseline measurements for maximal IMT (n=511), mean IMT (n=459), or Achilles tendon thickness (n=486). The IMT was measured annually, and Achilles tendon thickness was evaluated every two years.

Results: Higher LDL cholesterol (LDL-C) level and lower HDL cholesterol (HDL-C) level were associated with greater maximal and mean IMT as well as greater Achilles tendon thickness. Achilles tendon thickness tended to be greater in patients who had a smoking history than in never-smokers. Maximal IMT and Achilles tendon thickness were significantly greater in patients with CAD than in those without. Additionally, lower HDL-C level and hypertension were associated with higher values of maximal and mean IMT, suggesting the importance of comprehensive risk management including reduced HDL-C and blood pressure control in FH care. In longitudinal observations, percentage changes in maximal IMT and mean IMT gradually increased during the observation period. In contrast, percentage changes in Achilles tendon thickness became progressively thinner throughout the observation period.

Conclusions: We found a positive association between LDL-C levels and severity of carotid atherosclerosis in heterozygous FH patients on treatment. This observation suggests the insufficiency of lipid-lowering therapy and the presence of therapeutic inertia among clinicians in the real-world FH practice.

Aim: Elevated serum alkaline phosphatase (ALP) levels have been associated with increased risks of all-cause and cardiovascular mortality in patients receiving hemodialysis. However, little is known about the impact of serum ALP levels on the development of stroke, such as brain hemorrhage and infarction.

Methods: A total of 3,497 patients receiving maintenance hemodialysis registered in the multicenter observational Q-Cohort Study were analyzed. The primary outcomes were the incidences of brain hemorrhage and infarction. The covariate of interest was serum ALP levels. Patients were divided into tertiles based on their serum ALP levels (U/L) at baseline (T1, ＜69.3; T2, 69.3–98.4; T3, ＞98.4). The risks of brain hemorrhage, brain infarction, and composite stroke were estimated using Cox proportional hazards models and competing risk models with all-cause death as a competing risk.

Results: A total of 89 patients developed brain hemorrhage and 195 patients developed brain infarction during the 4-year follow-up period. The risk of brain hemorrhage in the highest tertile (T3) was significantly higher than that in the lowest tertile (T1) (multivariable-adjusted hazard ratio [95% confidence interval], 1.93 [1.12–3.35], subdistribution hazard ratio, 1.91 [1.10–3.30]). However, there was no significant association between serum ALP levels and the risk of brain infarction or composite stroke.

Conclusions: Higher serum ALP levels are associated with an increased risk of brain hemorrhage, but not brain infarction, in patients receiving maintenance hemodialysis. High serum ALP level is thus an important risk factor for brain hemorrhage in hemodialysis patients.

Aim: To identify the association between serum beta-2-microglobulin (B2M) or cystatin C (CysC) and asymptomatic carotid atherosclerosis in patients with primary aldosteronism (PA).

Methods: In this cross-sectional study, 265 subjects were enrolled, including 83 patients with PA, 91 with essential hypertension (EH), and 91 normotensive (NT) controls. B2M, CysC, plasma renin activity (PRA), and plasma aldosterone concentration (PAC) were measured, and the aldosterone-to-renin ratio (ARR) was calculated. Carotid intima-media thickness (cIMT), increased cIMT, and presence of carotid plaque or carotid stenosis ＜50% in the carotid artery were measured via ultrasonography to evaluate the degree of asymptomatic carotid atherosclerosis.

Results: CIMT increased in the NT, EH, and PA groups (0.60 (0.50, 0.80) mm vs. 0.80 (0.60, 1.00) mm vs. 0.90 (0.70, 1.10) mm, P＜0.01), so as the prevalence of increased cIMT and presence of carotid plaque (both P＜0.05). The B2M and CysC levels exhibited the same trend (B2M: 1.60±0.34 mg/L, 1.80±0.41 mg/L, 1.98±0.64 mg/L, P＜0.05; CysC: 0.76±0.12 mg/L, 0.88±0.17 mg/L, 0.94±0.23 mg/L, P＜0.05). B2M, CysC, PAC, and ARR were all positively associated with cIMT (all P＜0.01) in the PA group. After adjusting for potential confounders, B2M, PAC, but not CysC or ARR were independently associated with increased cIMT and presence of carotid plaque and carotid stenosis ＜50%, respectively. The receiver operating characteristic (ROC) curve analysis revealed that B2M and PAC demonstrated significant predictive ability for increased cIMT and presence of carotid plaque and carotid stenosis ＜50%.

Conclusion: B2M is an independent risk factor for asymptomatic carotid atherosclerosis in patients with PA.

Introduction: Primary dyslipidemias are inherited disorders in plasma lipoprotein metabolism that lead to serious cardiovascular and other complications. The Japanese Ministry of Health, Labor and Welfare (MHLW) covers medical expenses, under the Research Program on Rare and Intractable Diseases, for homozygous familial hypercholesterolemia (FH), familial chylomicronemia, sitosterolemia, cerebrotendinous xanthomatosis, lecithin:cholesterol acyltransferase deficiency, Tangier disease, and abetalipoproteinemia. Apolipoprotein A1 deficiency, heterozygous FH, and type III hyperlipoproteinemia are covered by the MHLW Pediatric Chronic Disease Program. Heterozygous FH and type III hyperlipoproteinemia are also important for their relatively common prevalence and, accordingly, high impact on Japanese public health by significant contribution to the overall prevalence of cardiovascular diseases. Therefore, a systemic survey of these diseases is mandatory to estimate their actual situation, such as prevalence, clinical manifestations, and prognoses among the Japanese population. The impact of these rare and intractable diseases on cardiovascular and other complications will likely be higher among Japanese people than other ethnicities because the general Japanese population has many cardioprotective aspects. The current study intends to conduct a multicenter registry of these diseases to assess their demographics and clinical features comprehensively.

Methods and Analysis: The Prospective Registry Study of Primary Dyslipidemia is a registry-based prospective, observational, multicenter cohort study in Japan, enrolling patients who fulfill the Japanese clinical criteria of the primary dyslipidemias listed above, from 26 participating institutes from August 2015 to March 2023. A total of 1,000 patients will be enrolled in the study and followed for 10 years. Clinical parameters are collected, including physical and laboratory findings, genetic analysis, drugs, lifestyle management, and clinical events, especially cardiovascular events. The primary endpoint of this study is the new onset of cardiovascular disease and acute pancreatitis, and the secondary endpoint is death from any causes.

Ethics and Dissemination: This study complies with the Declaration of Helsinki, the Ethical Guidelines for Medical and Health Research Involving Human Subjects, and all other applicable laws and guidelines in Japan. The institutional review boards have approved this study protocol at all participating institutes. The final results are to be published at appropriate international conferences and in peer-reviewed journals.