Takahiro Nishihara

Dr. Takahiro Nishihara

Okayama University, Okayama, Japan

Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 February 2023 in Nutrients
Verified
Journal Article
Open access
PDF file
MNMitsutaka Nakashima
Mitsutaka Nakashima
Kazufumi NakamuraKazufumi Nakamura
Kazufumi Nakamura
TNTakahiro Nishihara
Takahiro Nishihara
KIKeishi Ichikawa
Keishi Ichikawa
RNRie Nakayama
Rie Nakayama
HIHiroshi Ito
Hiroshi Ito
Cardiovascular diseases and liver diseases are closely related. Non-alcoholic fatty liver disease has the same risk factors as those for atherosclerotic cardiovascular disease and may also be a risk factor for atherosclerotic cardiovascular disease on its own. Heart failure causes liver fibrosis, and liver fibrosis results in worsened cardiac preload and congestion. Although some previous reports regard the association between cardiovascular diseases and liver disease, the management strategy for liver disease in patients with cardiovascular diseases is not still established. This review summarized the association between cardiovascular diseases and liver disease. In patients with non-alcoholic fatty liver disease, the degree of liver fibrosis progresses with worsening cardiovascular prognosis. In patients with heart failure, liver fibrosis could be a prognostic marker. Liver stiffness assessed with shear wave elastography, the fibrosis-4 index, and non-alcoholic fatty liver disease fibrosis score is associated with both liver fibrosis in patients with liver diseases and worse prognosis in patients with heart failure. With the current population ageing, the importance of management for cardiovascular diseases and liver disease has been increasing. However, whether management and interventions for liver disease improve the prognosis of cardiovascular diseases has not been fully understood. Future investigations are needed.

Verified
Journal Article
Open access
PDF file
YKYuji Koide
Yuji Koide
TMToru Miyoshi
Toru Miyoshi
TNTakahiro Nishihara
Takahiro Nishihara
MNMitsutaka Nakashima
Mitsutaka Nakashima
KIKeishi Ichikawa
Keishi Ichikawa
HIHiroshi Ito
Hiroshi Ito
The triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) ratio is an independent risk index for cardiovascular events. This study aimed to evaluate the association between TG/HDL-C ratio and coronary plaque characteristics as seen on coronary computed tomography angiography (CCTA) and the corresponding increase in the likelihood of cardiovascular events. A total of 935 patients who underwent CCTA for suspected coronary artery disease (CAD) were included. High-risk plaques (HRP) were defined based on three characteristics: positive remodeling, low-density plaques, and spotty calcification. Significant stenosis was defined as luminal narrowing of >70%. Patients with a higher TG/HDL-C ratio showed significantly greater prevalence of HRP and significant stenosis than patients with low TG/HDL-C ratios (p < 0.01). Multivariate logistic analysis demonstrated that the TG/HDL-C ratio was significantly associated with the presence of HRP (p < 0.01) but not with significant coronary stenosis (p = 0.24). During the median follow-up period of 4.1 years, 26 cardiovascular events including cardiovascular death and acute coronary syndrome occurred. The highest TG/HDL-C tertile was associated with cardiovascular events, with the lowest TG/HDL-C tertile as the reference (hazard ratio, 3.75; 95% confidence interval, 1.04–13.50). A high TG/HDL-C ratio is associated with the presence of CCTA-verified HRP, which can lead to cardiovascular events in patients with suspected CAD.

Verified
Journal Article
Open access
PDF file
TNTakahiro Nishihara
Takahiro Nishihara
TMToru Miyoshi
Toru Miyoshi
KIKeishi Ichikawa
Keishi Ichikawa
KOKazuhiro Osawa
Kazuhiro Osawa
MNMitsutaka Nakashima
Mitsutaka Nakashima
HIHiroshi Ito
Hiroshi Ito
Nonalcoholic fatty liver disease (NAFLD) is a risk factor for the development of atherosclerotic cardiovascular diseases (CVDs), and oxidative stress has been proposed as a shared pathophysiological condition. This study examined whether oxidized low-density lipoprotein (LDL) is involved in the underlying mechanism that links coronary atherosclerosis and NAFLD. This study included 631 patients who underwent coronary computed tomography angiography (CTA) for suspected coronary artery disease. NAFLD was defined on CT images as a liver-to-spleen attenuation ratio of <1.0. Serum-malondialdehyde-modified LDL (MDA-LDL) and coronary CTA findings were analyzed in a propensity-score-matched cohort of patients with NAFLD (n = 150) and those without NAFLD (n = 150). This study analyzed 300 patients (median age, 65 years; 64% men). Patients with NAFLD had higher MDA-LDL levels and a greater presence of CTA-verified high-risk plaques than those without NAFLD. In the multivariate linear regression analysis, MDA-LDL was independently associated with NAFLD (β = 11.337, p = 0.005) and high-risk plaques (β = 12.487, p = 0.007). Increased MDA-LDL may be a mediator between NAFLD and high-risk coronary plaque on coronary CTA. Increased oxidative stress in NAFLD, as assessed using MDA-LDL, may be involved in the development of CVDs.

26 August 2025 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
MNMitsutaka Nakashima
Mitsutaka Nakashima
TMToru Miyoshi
Toru Miyoshi
SHShohei Hara
Shohei Hara
RMRyosuke Miyagi
Ryosuke Miyagi
TNTakahiro Nishihara
Takahiro Nishihara
SYShinsuke Yuasa
Shinsuke Yuasa
Background/Objectives: Coronary CT angiography (CCTA) is a cornerstone in evaluating stable coronary artery disease (CAD), but conventional energy-integrating detector CT (EID-CT) has limitations, including calcium blooming and limited spatial resolution. Photon-counting detector CT (PCD-CT) may overcome these drawbacks through enhanced spatial resolution and improved tissue characterization. Methods: In this retrospective, propensity score–matched study, we compared CCTA findings from 820 patients (410 per group) who underwent either EID-CT or PCD-CT for suspected stable CAD. Primary outcomes included stenosis severity, high-risk plaque features, and downstream invasive coronary angiography (ICA) referral and yield. Results: The matched cohorts were balanced in demographics and cardiovascular risk factors (mean age 67 years, 63% male). PCD-CT showed a favorable shift in stenosis severity distribution (p = 0.03). High-risk plaques were detected less frequently with PCD-CT (22.7% vs. 30.5%, p = 0.01). Median coronary calcium scores did not differ (p = 0.60). Among patients referred for ICA, those initially evaluated with PCD-CT were more likely to undergo revascularization (62.5% vs. 44.1%), and fewer underwent potentially unnecessary ICA without revascularization (3.7% vs. 8.0%, p = 0.001). The specificity in diagnosing significant stenosis requiring revascularization was 0.74 with EID-CT and 0.81 with PCD-CT (p = 0.04). Conclusions: PCD-CT improved diagnostic specificity for CAD, reducing unnecessary ICA referrals while maintaining detection of clinically significant disease. This advanced CT technology holds promise for more accurate, efficient, and patient-centered CAD evaluation.