Kunihiko Matsui

A dipeptidyl peptidase-4 inhibitor, des-fluoro-sitagliptin, improves endothelial function and reduces atherosclerotic lesion formation in apolipoprotein E-deficient mice.

OBJECTIVES The aim of this study was to investigate the antiatherogenic effects of the dipeptidyl peptidase-4 inhibitor, des-fluoro-sitagliptin (DFS). BACKGROUND The new class of anti-type 2 diabetes drugs, dipeptidyl peptidase-4 inhibitors, improves glucose metabolism by increasing levels of active glucagon-like peptide (GLP)-1. METHODS Endothelial function was examined by acetylcholine-induced endothelium-dependent vasorelaxation using aortic rings and atherosclerotic lesion development in the entire aorta in apolipoprotein E-deficient mice fed a high-fat diet with or without DFS, and the antiatherogenic effects of DFS were investigated in cultured human macrophages and endothelial cells. Plasma levels of active GLP-1 were measured in patients with or without coronary artery disease. RESULTS DFS significantly improved endothelial dysfunction (89.9 ± 3.9% vs. 79.2 ± 4.3% relaxation at 10(-4) mol/l acetylcholine, p < 0.05) associated with increased endothelial nitric oxide synthase phosphorylation and reduced atherosclerotic lesion area (17.7% [15.6% to 25.8%] vs. 24.6% [19.3% to 34.6%], p < 0.01) compared with vehicle treatment. In cultured human macrophages, DFS significantly increased GLP-1-induced cytosolic levels of cyclic adenosine monophosphate compared with GLP-1 alone, resulted in inhibiting phosphorylation of c-jun N-terminal kinase and extracellular signal-regulated kinase 1/2 and nuclear factor-kappa B p65 nuclear translocation through the cyclic adenosine monophosphate/protein kinase A pathway, and suppressed proinflammatory cytokines (i.e., interleukin-1-beta, interleukin-6, and tumor necrosis factor-alpha) and monocyte chemoattractant protein-1 production in response to lipopolysaccharide. DFS-enhanced GLP-1 activity sustained endothelial nitric oxide synthase phosphorylation and decreased endothelial senescence and apoptosis compared with GLP-1 alone. In the human study, fasting levels of active GLP-1 were significantly lower in patients with coronary artery disease than those without (3.10 pmol/l [2.40 to 3.62 pmol/l] vs. 4.00 pmol/l [3.10 to 5.90 pmol/l], p < 0.001). CONCLUSIONS A DPP-4 inhibitor, DFS, exhibited antiatherogenic effects through augmenting GLP-1 activity in macrophages and endothelium.

Significance of a Multiple Biomarkers Strategy Including Endothelial Dysfunction to Improve Risk Stratification for Cardiovascular Events in Patients at High Risk for Coronary Heart Disease

OBJECTIVES We investigated whether a multiple biomarkers strategy that includes plasma levels of endothelium-derived microparticles (EMP), reflecting endothelial dysfunction, can improve prediction of future cardiovascular events in patients at high risk for coronary heart disease (CHD). BACKGROUND Detailed risk stratification using multiple biomarkers can provide clinical benefits in high-risk patients. Endothelial dysfunction has been described as a predictor of cardiovascular complications. METHODS We measured 3 biomarkers in 488 consecutive patients with various CHD risks: B-type natriuretic peptide (BNP), high-sensitivity C-reactive protein (hsCRP), and EMP. We followed 387 stable patients at high risk for CHD and examined future cardiovascular events. RESULTS During a mean follow-up of 36 months, 55 patients developed cardiovascular events. Multivariate Cox proportional hazards analysis adjusted for established risk factors identified age, BNP, hsCRP, and EMP as significant and independent predictors of future cardiovascular events (age: hazard ratio [HR]: 1.042, 95% confidence interval [CI]: 1.007 to 1.080, p = 0.02; BNP: HR: 1.242, 95% CI: 1.004 to 1.536, p = 0.046; hsCRP: HR: 1.468, 95% CI: 1.150 to 1.875, p = 0.002; EMP: HR: 1.345, 95% CI: 1.094 to 1.652, p = 0.005). The C statistics for cardiovascular events increased when each biomarker or combinations of biomarkers were added to the Framingham risk model (C statistics: Framingham risk model alone 0.636, Framingham risk + BNP 0.695, Framingham risk + hsCRP 0.696, Framingham risk + EMP 0.682, and Framingham risk + BNP + hsCRP + EMP 0.763). CONCLUSIONS The assessment of endothelial dysfunction by plasma levels of EMP can independently predict future cardiovascular events in patients at high risk for CHD. A multiple biomarkers strategy that includes endothelial dysfunction assessed by EMP can identify patients vulnerable to cardiovascular disease. (University Hospital Medical Information Network number: UMIN000000876).

Digital assessment of endothelial function and ischemic heart disease in women.

OBJECTIVES We investigated the utility of digital reactive hyperemia peripheral arterial tonometry (RH-PAT) in predicting ischemic heart disease (IHD), including obstructive coronary artery disease (CAD) and nonobstructive coronary artery disease (NOCAD), in women. BACKGROUND IHD is the leading cause of mortality, and its pathogenesis is diverse in women. Fingertip RH-PAT is a new device that provides noninvasive, automatic, and quantitative evaluation of endothelial dysfunction. METHODS RH-PAT was measured using Endo-PAT2000 (Itamar Medical, Caesarea, Israel) before cardiac catheterization in 140 stable women scheduled for hospitalization to examine chest pain. NOCAD was diagnosed by angiography with measurement of coronary blood flow and cardiac lactate production during intracoronary acetylcholine provocation test and cardiac scintigraphy with stress tests. RESULTS Sixty-eight women (49%) had obstructive CAD and 42 women (30%) had NOCAD. RH-PAT indexes were significantly attenuated in both obstructive CAD and NOCAD as compared with non-IHD (n = 30) (obstructive CAD: median 1.57, interquartile range [IQR] 1.42 to 1.76; NOCAD: median 1.58, IQR 1.41 to 1.78; non-IHD: median 2.15, IQR 1.85 to 2.48, p < 0.001). By multivariate logistic regression analysis, only RH-PAT index was significantly associated with IHD, including obstructive CAD and NOCAD (odds ratio 0.51; 95% confidence interval: 0.38 to 0.68; p < 0.001). In receiver-operating characteristic analysis, RH-PAT index was a significant predictor of IHD (area under the curve 0.86; p < 0.001). Furthermore, only RH-PAT was useful for the prediction of NOCAD after excluding obstructive CAD (area under the curve 0.85; p < 0.001; RH-PAT index of <1.82 had 81% sensitivity and 80% specificity). CONCLUSIONS RH-PAT indexes were significantly attenuated in women with IHD. Digital RH-PAT can predict patients with IHD, especially NOCAD before angiography. RH-PAT is potentially useful for identifying high-risk women for IHD. (Endothelial Dysfunction and Coronary Artery Spasm; NCT00619294).

Peripheral Endothelial Function and Cardiovascular Events in High-Risk Patients

Background Endothelial dysfunction is a key component of vascular vulnerability. Reactive hyperemia index (RHI), as assessed by the peripheral arterial tonometry, can noninvasively evaluate endothelial function. This study was designed to determine the additional prognostic value of endothelial function to the Synergy Between PCI With Taxus and Cardiac Surgery Score (SYNTAXsc) and the Framingham Risk Score (FRS) in predicting cardiovascular events in high‐risk patients. Methods and Results We undertook a two‐center prospective study in 528 stable patients at high‐risk for cardiovascular events from the years 2006–2011. The RHI was measured before coronary angiography and coronary complexity was assessed by SYNTAXsc. After optimal therapies including coronary revascularization, there was follow‐up with patients until August 2012. Cardiovascular events consist of cardiovascular death, myocardial infarction, unstable angina, ischemic stroke, coronary revascularization, heart failure‐induced hospitalization, aortic disease, and peripheral arterial disease. During 1468 person‐years of follow‐up, 105 patients developed cardiovascular events. Multivariate Cox proportional hazards analysis identified B‐type natriuretic peptide (BNP), SYNTAXsc, and RHI as independent cardiovascular event predictors (hazard ratio [95% confidence interval]: natural logarithm of BNP per 0.1: 1.019 [1.002 to 1.037]; P=0.023, SYNTAXsc per tertile: 2.426 [1.825 to 3.225]; P<0.0001, RHI per 0.1: 0.761 [0.673 to 0.859]; P<0.0001). When RHI was added to the FRS, BNP, and SYNTAXsc, net reclassification index was significantly improved (27.5%; P<0.0001), with a significant increase in the C‐statistic (from 0.728 [0.679 to 0.778] to 0.766 [0.726 to 0.806]; P=0.031). Conclusions Advanced endothelial dysfunction significantly correlated with near future cardiovascular events in high‐risk patients. This physiological vascular measurement improved risk discrimination when added to the FRS, BNP, and SYNTAXsc. Clinical Trial Registration URL: clinicaltrials.gov (http://www.clinicaltrials.gov). Unique identifier: NCT00737945.

Association of pericardial fat accumulation rather than abdominal obesity with coronary atherosclerotic plaque formation in patients with suspected coronary artery disease

OBJECTIVES The purpose of this study was to examine the association of pericardial fat with the presence of coronary plaques. BACKGROUND Waist circumference, reflecting abdominal obesity, is a risk factor of metabolic syndrome and coronary artery disease (CAD). Adipose tissue secretes many factors implicated in atherogenesis, however, the role of pericardial fat (ectopic visceral fat around coronary arteries) in the pathogenesis of CAD is not clear. METHODS We measured total pericardial fat volume (PFV) and determined presence and characteristics of coronary plaques using 64-slice computed tomography in 171 consecutive patients suspected of CAD (101 men; mean age, 66+/-11 years, +/-SD). RESULTS PFV correlated with age (p<0.05), body mass index (p<0.05), waist circumference (p<0.01), and high-density lipoprotein cholesterol (p<0.01) by multivariate regression analysis. PFV was significantly larger in patients with coronary plaques, even nonstenotic or noncalcified ones, than those without plaques (any plaques, n=123; 201+/-71cm(3), nonstenotic plaques, n=51; 192+/-63, noncalcified plaques, n=32; 196+/-56 vs. no plaque, n=48; 144+/-45, p<0.001, respectively). Multivariate backward logistic regression analysis demonstrated that PFV, but not waist circumference, significantly associated with the presence of any coronary plaques (odds ratio [OR]; 2.876, 95% confidence interval [95% CI]; 1.614-5.125, p<0.001), nonstenotic plaques confirmed by coronary angiography (OR; 3.423, 95% CI; 1.764-6.642, p<0.001), and noncalcified plaques (OR; 3.316, 95% CI; 1.435-7.661, p<0.01). CONCLUSIONS PFV correlated significantly with the presence of nonstenotic and noncalcified coronary plaques assessed by multislice computed tomography. Pericardial fat is more highly associated with early development of CAD than simple anthropometric measures of abdominal obesity.

Prognostic value of endothelial microparticles in patients with heart failure

Heart failure (HF) is associated with endothelial dysfunction. Endothelium‐derived microparticles (EMPs) are a novel quantitative plasma marker of endothelial dysfunction. We investigated whether plasma levels of EMPs can predict future cardiovascular events in patients with HF.

Coronary Vasomotor Response to Intracoronary Acetylcholine Injection, Clinical Features, and Long-term Prognosis in 873 Consecutive Patients With Coronary Spasm: Analysis of a Single-Center Study Over 20 Years

Background The aim of this study was to elucidate the correlation between angiographic coronary vasomotor responses to intracoronary acetylcholine (ACh) injection, clinical features, and long‐term prognosis in patients with vasospastic angina (VSA). Methods and Results This is a retrospective, observational, single‐center study of 1877 consecutive patients who underwent ACh‐provocation test between January 1991 and December 2010. ACh‐provoked coronary spasm was observed in 873 of 1637 patients included in the present analysis. ACh‐positive patients were more likely to be older male smokers with dyslipidemia, to have a family history of ischemic heart disease, and to have a comorbidity of coronary epicardial stenosis than were ACh‐negative patients. ACh‐positive patients were divided into 2 groups: those with focal (total or subtotal obstruction, n=511) and those with diffuse (severe diffuse vasoconstriction, n=362) spasm patterns. Multivariable logistic regression analysis identified female sex and low comorbidity of coronary epicardial stenosis to correlate with the ACh‐provoked diffuse spasm pattern in patients with VSA. Kaplan–Meier survival curve indicated better 5‐year survival rates free from major adverse cardiovascular events in patients with diffuse spasm pattern compared with those with focal spasm pattern (P=0.019). Multivariable Cox hazard regression analysis identified diffuse spasm pattern as a negative predictor of major adverse cardiovascular events in patients with VSA. Conclusions ACh‐induced diffuse coronary spasm was frequently observed in female VSA patients free of severe coronary epicardial stenosis and was associated with better prognosis than focal spasm. These results suggest the need to identify the ACh‐provoked coronary spasm subtypes in patients with VSA.

Comorbidity as a correlate of length of stay for hospitalized patients with acute chest pain

OBJECTIVE: To determine whether comorbid medical conditions as measured with the Charlson Comorbidity Index are independent correlates of length of stay after adjusting for other clinical and socioeconomic data.DESIGN: Prospective cohort study.SETTING: Urban teaching hospital.PATIENTS: All 1,261 patient aged 30 years or more who were admitted to this hospital after coming to the emergency department with acute chest pain between October 1990 and May 1992.MEASUREMENTS AND OUTCOMES: Clinical data including comorbid medical conditions used in the Charlson index were prospectively recorded by the evaluating physician at the time of admission or by a research nurse who was blinded to the subsequent events. History of myocardial infarction was excluded from the calculation of the Charlson index score. Charlson index scores were 0 to 1 for 921 patients (73%), 2 to 3 for 263 (21%), and greater than 3 for 77 (6%). Unadjusted mean (±SD) lengths of stay in these groups were 4.4±5.2, 5.2±5.9, and 7.5±9.3 days, respectively. In multiple linear regression analysis, compared with Charlson index scores of 0 to 1, scores of 2 to 3 and greater than 3 were significant (p<.01) independent correlates of the log transformation of length of stay after adjusting for clinical data from the initial presentation and subsequent course (modelR2=.510). In an analysis restricted to the 795 patients without clinical complications, a Charlson index score greater than 3 was an independent correlate of length of stay compared with scores of 0 to 1 (p<.01). Individual comorbid conditions were not significant correlates of length of stay after controlling for Charlson index score.CONCLUSIONS: In this population of patients with acute chest pain, comorbidity as measured with the Charlson index was independently associated with length of stay after adjustment for other clinical data. After adjusting for the Charlson index, no separate comorbid condition was significantly correlated with length of stay. These findings suggest that the Charlson index can be used to adjust for comorbidities in analyses of length of stay for patients with this condition.

Angiotensin II Receptor Blocker-based Therapy in Japanese Elderly, High-risk, Hypertensive Patients

BACKGROUND It is unknown whether high-dose angiotensin II receptor blocker therapy or angiotensin II receptor blocker + calcium channel blocker combination therapy is better in elderly hypertensive patients with high cardiovascular risk. The objective of the study was to compare the efficacy of these treatments in elderly, high-risk Japanese hypertensive patients. METHODS The OlmeSartan and Calcium Antagonists Randomized (OSCAR) study was a multicenter, prospective, randomized, open-label, blinded-end point study of 1164 hypertensive patients aged 65 to 84 years with type 2 diabetes or cardiovascular disease. Patients with uncontrolled hypertension during treatment with olmesartan 20 mg/d were randomly assigned to receive 40 mg/d olmesartan (high-dose angiotensin II receptor blocker) or a calcium channel blocker + 20 mg/d olmesartan (angiotensin II receptor blocker + calcium channel blocker). The primary end point was a composite of cardiovascular events and noncardiovascular death. RESULTS During a 3-year follow-up, blood pressure was significantly lower in the angiotensin II receptor blocker + calcium channel blocker group than in the high-dose angiotensin II receptor blocker group. Mean blood pressure at 36 months was 135.0/74.3 mm Hg in the high-dose angiotensin II receptor blocker group and 132.6/72.6 mm Hg in the angiotensin II receptor blocker + calcium channel blocker group. More primary end points occurred in the high-dose angiotensin II receptor blocker group than in the angiotensin II receptor blocker + calcium channel blocker group (58 vs 48 events, hazard ratio [HR], 1.31, 95% confidence interval, 0.89-1.92; P=.17). In patients with cardiovascular disease at baseline, more primary events occurred in the high-dose angiotensin II receptor blocker group (HR, 1.63, P=.03); in contrast, fewer events were observed in the subgroup without cardiovascular disease (HR, 0.52, P=.14). This treatment-by-subgroup interaction was significant (P=.02). CONCLUSION The angiotensin II receptor blocker and calcium channel blocker combination lowered blood pressure more than the high-dose angiotensin II receptor blocker and reduced the incidence of primary end points more than the high-dose angiotensin II receptor blocker in patients with cardiovascular disease. The addition of a second antihypertensive agent is more effective at lowering blood pressure than simply doubling the dose of an existing agent.

Quantitative Evaluation of the Diagnostic Thinking Process in Medical Students

OBJECTIVE: To explore the diagnostic thinking process of medical students.SUBJECTS AND METHODS: Two hundred twenty-four medical students were presented with 3 clinical scenarios corresponding to high, low, and intermediate pre-test probability of coronary artery disease. Estimates of test characteristics of the exercise stress test, and pre-test and post-test probability for each scenario were elicited from the students (intuitive estimates) and from the literature (reference estimates). Post-test probabilities were calculated using Bayes’ theorem based upon the intuitive estimates (Bayesian estimates of post-test probability) and upon the reference estimates (reference estimates of post-test probability). The differences between the reference estimates and the intuitive estimates, and between Bayesian estimates and the intuitive estimates were used for assessing knowledge of test characteristics, and ability of estimating pre-test and post-test probability of disease.RESULTS: Medical students could not rule out disease in low or intermediate pre-test probability settings, mainly because of poor pre-test estimates of disease probability. They were also easily confused by test results that differed from their anticipated results, probably because of their inaptitude in applying Bayes’ theorem to real clinical situations. These diagnostic thinking patterns account for medical students or novice physicians repeating unnecessary examinations.CONCLUSIONS: Medical students’ diagnostic ability may be enhanced by the following educational strategies: 1) emphasizing the importance of ruling out disease in clinical practice, 2) training in the estimation of pre-test disease probability based upon history and physical examination, and 3) incorporation of the Bayesian probabilistic thinking and its application to real clinical situations.