Fasting hypertriglyceridemia is positively associated with the morbidity of coronary heart disease (CHD), and postprandial (non-fasting) hypertriglyceridemia is also correlated with the risk status for CHD, which is related to the increase in chylomicron (CM) remnant lipoproteins produced from the intestine. CM remnant particles, as well as oxidized low density lipoprotein (LDL) or very low density lipoprotein (VLDL) remnants, are highly atherogenic and act by enhancing systemic inflammation, platelet activation, coagulation, thrombus formation, and macrophage foam cell formation. The cholesterol levels of remnant lipoproteins significantly correlate with small, dense LDL; impaired glucose tolerance (IGT) and CHD prevalence. We have developed an assay of apolipoprotein (apo)B-48 levels to evaluate the accumulation of CM remnants. Fasting apoB-48 levels correlate with the morbidity of postprandial hypertriglyceridemia, obesity, type III hyperlipoproteinemia, the metabolic syndrome, hypothyroidism, chronic kidney disease, and IGT. Fasting apoB-48 levels also correlate with carotid intima-media thickening and CHD prevalence, and a high apoB-48 level is a significant predictor of CHD risk, independent of the fasting TG level. Diet interventions, such as dietary fibers, polyphenols, medium-chain fatty acids, diacylglycerol, and long-chain n-3 polyunsaturated fatty acids (PUFA), ameliorate postprandial hypertriglyceridemia, moreover, drugs for dyslipidemia (n-3 PUFA, statins, fibrates or ezetimibe) and diabetes concerning incretins (dipeptidyl-peptidase IV inhibitor or glucagon like peptide-1 analogue) may improve postprandial hypertriglyceridemia. Since the accumulation of CM remnants correlates to impaired lipid and glucose metabolism and atherosclerotic cardiovascular events, further studies are required to investigate the characteristics, physiological activities, and functions of CM remnants for the development of new interventions to reduce atherogenicity.

Atherosclerosis is a chronic inflammatory disease. Interventions targeting the inflammatory process could provide new strategies for preventing atherosclerotic cardiovascular diseases (CVD). Previously, we have reported that oral administration of anti-CD3 antibodies, or active vitamin D₃, reduced atherosclerosis in mice via recruiting regulatory T cells and tolerogenic dendritic cells to the gut-associated lymphoid tissues. From this, it is reasonable to propose that the intestine could be a novel therapeutic target for prevention of atherosclerotic CVD. Recently, the association between cardio-metabolic diseases and gut microbiota has attracted increased attention. Gut microbiota, reported to be highly associated with intestinal immunity and metabolism, were shown to aggravate CVD by contributing to the production of trimethylamine-N-oxide (TMAO), a pro-atherogenic compound. We have also previously investigated the relationship between patient susceptibility to coronary artery disease (CAD) and gut microbiota. We found that the order Lactobacillales was significantly increased and the phylum Bacteroidetes was decreased in CAD patients compared with control patients. In this review article, we discuss the evidence for the relationship between the gut microbiota and cardio-metabolic diseases, and consider the gut microbiota as new potential diagnostic and therapeutic tool for treating CVD.

Aim: Clinical trials suggest that residual risks remain for coronary artery disease (CAD) during low-density lipoprotein cholesterol (LDL-C) lowering therapy. We aimed to investigate the role of exogenous lipids in the prognosis of CAD after percutaneous coronary intervention (PCI).

Methods: A total of 145 patients with CAD, who underwent elective PCI, and 82 non-CAD (control) patients were enrolled in this study. CAD patients underwent follow-up coronary angiography 6–9 months after PCI, and were classified into three groups: 1) patients who showed in-stent restenosis (ISR) in the original stented segment, 2) patients with other non-target coronary atherosclerotic lesions (de novo), and 3) patients with neither ISR nor a de novo lesion. Biochemical analyses were performed on fasting serum samples at the time of follow-up coronary angiography.

Results: Despite the controlled serum LDL-C levels, CAD patients with statin showed elevated cholesterol absorption marker campesterol/total cholesterol (TC), synthesis marker lathosterol/TC, campesterol/lathosterol ratio, and apolipoprotein B48 (apoB48) concentration compared with non-CAD patients. The high campesterol/TC, campesterol/lathosterol ratio, and apoB48 concentration were associated with de novo lesion progression after PCI. In stepwise multivariate logistic regression analysis, campesterol/TC and apoB48 concentrations were independent risk factors for de novo lesion progression in statin-treated CAD patients after PCI.

Conclusion: The increase of cholesterol absorption marker and apoB48 concentration may lead to the progression of de novo lesions, and these markers may represent a residual risk during statin treatment after PCI.

Aim: Atherosclerosis-prone apolipoprotein E (apoE) or low-density lipoprotein receptor (LDL-R) knockout (KO) mice are generally resistant to developing coronary atherosclerosis (CA) and ischemic heart disease (IHD). However, studies have demonstrated the occurrence of spontaneous CA and IHD in scavenger receptor class B type 1 (SR-BI)/apoE double KO (dKO) mice, which suggests that SR-BI could be a potential target for the prevention and therapy of CA and IHD. This possibility was later investigated in SR-BI/LDL-R dKO mice, but no signs of CA or IHD was identified when mice were fed a normal western-type diet. Here we explored whether SR-BI deletion could result in CA and IHD in LDL-R KO mice when fed a modified western-type diet containing higher (0.5%) cholesterol.

Methods: Cardiac functions were detected by electrocardiography, single photon emission computed tomography (SPECT), echocardiography (Echo) and 2,3,5-triphenyltetrazolium chloride staining. CA was visualized by hematoxylin-eosin staining.

Results: After 12 weeks on the modified diet, SR-BI/LDL-R dKO mice developed cardiac ischemia/infarction, together with systolic dysfunction and left ventricular dilatation. CA was most severe at the aortic sinus level to an extent that no dKO mice survived to 20 weeks on the modified diet. None of control mice, however, developed CA or IHD.

Conclusions: SR-BI deletion led to CA and IHD in LDL-R KO mice when fed the modified western-type diet. We established SR-BI/LDL-R dKO mice as a diet-induced murine model of human IHD and developed detection methods, using a combination of SPECT and Echo, for effective in vivo evaluation of cardiac functions.

Aim: Patients with orthostatic hypotension (OH) have high arterial stiffness. Patients with diabetes mellitus (DM) often have cardiac autonomic neuropathy that leads to OH; however, whether OH is an indicator of arterial stiffness progression is unclear. We aimed to investigate whether the cardio-ankle vascular index (CAVI) varies between DM patients with and without OH using the sit-to-stand test (STST).

Methods: One hundred and fifty-nine patients with DM underwent CAVI assessment and blood pressure (BP) and heart rate change evaluation during the STST. OH was defined as a decline in systolic BP (SBP) and/or diastolic BP of at least 20 mmHg or 10 mmHg, respectively, in the initial and late upright positions compared with that in the sitting position.

Results: OH was diagnosed in 42 patients (26.4%). DM patients with OH had significantly higher CAVI (9.36±1.15 versus 8.89±1.18, p=0.026) than those without OH. CAVI was significantly inversely correlated with systolic and diastolic BP changes (R=－0.347, p＜0.001 and R=－0.314, p＜0.001, respectively) in the initial upright position. Multivariate regression analysis revealed that age, SBP changes, and low frequency component in the initial upright position were independent determinants of CAVI.

Conclusion: Patients with DM having large BP drops occurring when moving from sitting to standing have high arterial stiffness. A significant BP drop during the STST necessitates careful evaluation of advanced arterial stiffness in patient with DM.

Aim: Glucagon-like peptide-1 can reduce both postprandial plasma glucose (PG) and chylomicron (CM) levels in patients with type 2 diabetes. However, there have been no reports regarding the relationship between the postprandial metabolism of PG and CM.

Methods: Patients with type 2 diabetes who were admitted for glycemic control were randomized to insulin alone (Ins; n=16) or insulin plus vildagliptin 100 mg (InsV; n=16) groups. The insulin dose was adjusted to maintain normal blood glucose levels. The daily profiles of serum TG, remnant lipoprotein cholesterol (RemL-C), and apolipoprotein B48 (ApoB48) were estimated by frequent blood collection on admission and before discharge, and the daily glucose fluctuation profile was also estimated using continuous glucose monitoring (CGM) before discharge.

Results: The daily profiles of serum TG and RemL-C indicated a significant decrease before discharge compared with on admission; however, no significant changes in serum ApoB48 levels were observed in either group. At discharge, daily glucose fluctuation profile and the change in the serum ApoB48 level from fasting to the peak of the daily profile was significantly smaller in the InsV group than in the Ins group. The increment of serum ApoB48 level was significantly correlated with the mean amplitude of glycemic excursions calculated using CGM data only in the Ins group (R²= 0.5242,P＜0.001).

Conclusions: Short-term glycemic control decreased serum TG and RemL-C levels, but not ApoB48 levels, and the postprandial metabolism of PG and CM might be regulated by the same mechanism except GLP-1 effect.

Aim: Recently, much attention has been focused on partial thrombosis of the false lumen in patients with acute aortic dissection. However, its effect on clinical outcomes in these patients, especially in case of acute type A aortic dissection, has not been clearly elucidated. This study evaluated the influence of the false lumen status, including partial thrombosis, on short-term clinical outcomes in acute type A aortic dissection patients without urgent surgical treatment.

Methods: Sixty-two patients (29 males, mean age 73±13 years) with acute type A aortic dissection who did not receive urgent surgical treatment at four hospitals were enrolled. Patients were divided into three groups based on the false lumen status on enhanced computed tomography image (complete thrombosis, n=28; partial thrombosis, n=27; patent, n=7). Patients with partial thrombosis were further divided into two groups (thrombus-dominant, n=15; flow-dominant, n=12).

Results: The short-term mortality rate (in-hospital and 30-day) was significantly higher in patients with a patent false lumen, while no significant difference was seen between the other two groups. Patients with flow-dominant partial thrombosis had significantly higher short-term mortality rate than those with thrombus-dominant partial thrombosis (in-hospital, p=0.001 and 30-day, p＜0.001).

Conclusions: The short-term mortality rate in acute type A aortic dissection patients without urgent surgical treatment was lower in patients with partial thrombosis of the false lumen than in those with a patent false lumen. Furthermore, patients with flow-dominant partial thrombosis had higher mortality rate than those with thrombus-dominant partial thrombosis.

Aim: To evaluate the role of CHADS₂ and CHA₂DS₂-VASc scores in predicting the risk of ischemic stroke or transient ischemic attack (TIA) outcomes in patients with interatrial block (IAB) without a history of atrial fibrillation (AF).

Methods: A retrospective study was conducted, including 1,046 non-anticoagulated inpatients (612 males, 434 females; mean age: 63±10 years) with IAB and without AF. IAB was defined as P-wave duration ＞120 ms using a 12-lead electrocardiogram. CHADS₂ and CHA₂DS₂-VASc scores were retrospectively calculated. The primary outcomes evaluated were ischemic stroke or TIA.

Results: During the mean follow-up period of 4.9±0.7 years, 55 (5.3%) patients had an ischemic stroke or TIA. Receiver operating characteristic (ROC) curve analysis showed that the CHADS₂ score [area under the curve (AUC), 0.638; 95% confidence interval (CI), 0.562–0.715; P=0.001] and the CHA₂DS₂-VASc score (AUC, 0.671; 95% CI, 0.599–0.744; P＜0.001) were predictive of ischemic strokes or TIA. Cut-off point analysis showed that a CHADS₂ score ≥3 (sensitivity=0.455 and specificity=0.747) and a CHA₂DS₂-VASc score ≥4 (sensitivity=0.564 and specificity=0.700) provided the highest predictive value for ischemic stroke or TIA. The multivariate Cox regression analysis showed that CHADS₂ [hazard ratio (HR), 1.442; 95% CI, 1.171–1.774; P=0.001] and CHA₂DS₂-VASc (HR, 1.420; 95% CI, 1.203–1.677; P＜0.001) scores were independently associated with ischemic stroke or TIA following adjustment for smoking, left atrial diameter, antiplatelet agents, angiotensin inhibitors, and statins.

Conclusions: CHADS₂ and CHA₂DS₂-VASc scores may be predictors of risk of ischemic stroke or TIA in patients with IAB without AF.