Takahiro Okumura

Dr. Takahiro Okumura

orcid

Research Focus & Metrics

Academic Career Length

24Years (2003-Present)

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

Representative Publications

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29 June 2022 in European Heart Journal
Verified
Journal Article
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TNTakeru Nabeta
Takeru Nabeta
TKTakeshi Kitai
Takeshi Kitai
YNYoshihisa Naruse
Yoshihisa Naruse
TTTatsunori Taniguchi
Tatsunori Taniguchi
KYKenji Yoshioka
Kenji Yoshioka
YMYuya Matsue
Yuya Matsue
This study evaluated the prognosis and prognostic factors of patients with cardiac sarcoidosis (CS), an underdiagnosed disease. Patients from a retrospective multicentre registry, diagnosed with CS between 2001 and 2017 based on the 2016 Japanese Circulation Society or 2014 Heart Rhythm Society criteria, were included. The primary endpoint was a composite of all-cause death, hospitalization for heart failure, and documented fatal ventricular arrhythmia events (FVAE), each constituting exploratory endpoints. Among 512 registered patients, 148 combined events (56 heart failure hospitalizations, 99 documented FVAE, and 49 all-cause deaths) were observed during a median follow-up of 1042 (interquartile range: 518–1917) days. The 10-year estimated event rates for the primary endpoint, all-cause death, heart failure hospitalizations, and FVAE were 48.1, 18.0, 21.1, and 31.9%, respectively. On multivariable Cox regression, a history of ventricular tachycardia (VT) or fibrillation [hazard ratio (HR) 2.53, 95% confidence interval (CI) 1.59–4.00, P < 0.001], log-transformed brain natriuretic peptide (BNP) levels (HR 1.28, 95% CI 1.07–1.53, P = 0.008), left ventricular ejection fraction (LVEF) (HR 0.94 per 5% increase, 95% CI 0.88–1.00, P = 0.046), and post-diagnosis radiofrequency ablation for VT (HR 2.65, 95% CI 1.02–6.86, P = 0.045) independently predicted the primary endpoint. Although mortality is relatively low in CS, adverse events are common, mainly due to FVAE. Patients with low LVEF, with high BNP levels, with VT/fibrillation history, and requiring ablation to treat VT are at high risk. Clinical characteristics, findings on cardiovascular imaging, prognosis, and prognostic factors in patients with cardiac sarcoidosis: summary results of ILLUMINATE-CS.

1 June 2018 in Canadian Journal of Cardiology
Verified
Journal Article
Closed access
SYShogo Yamaguchi
Shogo Yamaguchi
RMRyota Morimoto
Ryota Morimoto
TOTakahiro Okumura
Takahiro Okumura
YYYuta Yamashita
Yuta Yamashita
THTomoaki Haga
Tomoaki Haga
TMToyoaki Murohara
Toyoaki Murohara

15 February 2022 in Journal of the American Heart Association
Verified
Journal Article
Open access
PDF file
TKToru Kondo
Toru Kondo
TOTakahiro Okumura
Takahiro Okumura
NSNaoki Shibata
Naoki Shibata
TITakahiro Imaizumi
Takahiro Imaizumi
KDKaoru Dohi
Kaoru Dohi
TMToyoaki Murohara
Toyoaki Murohara
Background: Prognoses and long‐term cardiac function of patients with fulminant myocarditis have not been fully elucidated. Therefore, we clarified the prognoses and long‐term cardiac function according to required percutaneous mechanical circulatory support and histological findings among patients with fulminant myocarditis. Methods and Results: We conducted a multicenter retrospective medical record review of 216 patients with fulminant myocarditis requiring percutaneous mechanical circulatory support. Sixty‐one patients were treated with intra‐aortic balloon pump or Impella alone, and 155 patients received veno‐arterial extracorporeal membrane oxygenation and were treated with or without intra‐aortic balloon pump or Impella. Histologically, 107 patients had lymphocytic myocarditis; 34, eosinophilic myocarditis; and 4, giant cell myocarditis. Freedom from composite end point (death, durable left ventricular assist device implantation, and heart transplantation) was 66% at 90 days, 62% at 1 year, and 57% at 6 years. Veno‐arterial extracorporeal membrane oxygenation use was associated with poor prognosis in the multivariable analysis (hazard ratio [HR], 5.27; 95% CI, 1.60–17.36). The eosinophilic myocarditis subgroup showed better prognosis (HR, 0.28; 95% CI, 0.10–0.80) compared with the lymphocytic myocarditis subgroup but not in the multivariable analysis. Ventricular tachycardia/ventricular fibrillation rhythm at admission, high C‐reactive protein level, and no endomyocardial biopsy were also associated with poor prognosis. The left ventricular ejection fraction at 1 year was ≤50% in 16% of patients and was lower in patients with eosinophilic myocarditis (median: 57.9% [48.8–65.0%]) than in those with lymphocytic myocarditis (65.0% [58.6–68.7%]) ( P =0.036). Conclusions: Patients with fulminant myocarditis who received veno‐arterial extracorporeal membrane oxygenation had a poor prognosis. Long‐term cardiac function was impaired in some patients, especially those with eosinophilic myocarditis.

12 September 2024 in Nature Communications
Verified
Journal Article
Open access
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SYSatoya Yoshida
Satoya Yoshida
TYTatsuya Yoshida
Tatsuya Yoshida
KIKohei Inukai
Kohei Inukai
KKKatsuhiro Kato
Katsuhiro Kato
YYYoshimitsu Yura
Yoshimitsu Yura
MTMikito Takefuji
Mikito Takefuji
Chronic fibrotic tissue disrupts various organ functions. Despite significant advances in therapies, mortality and morbidity due to heart failure remain high, resulting in poor quality of life. Beyond the cardiomyocyte-centric view of heart failure, it is now accepted that alterations in the interstitial extracellular matrix (ECM) also play a major role in the development of heart failure. Here, we show that protein kinase N (PKN) is expressed in cardiac fibroblasts. Furthermore, PKN mediates the conversion of fibroblasts into myofibroblasts, which plays a central role in secreting large amounts of ECM proteins via p38 phosphorylation signaling. Fibroblast-specific deletion of PKN led to a reduction of myocardial fibrotic changes and cardiac dysfunction in mice models of ischemia-reperfusion or heart failure with preserved ejection fraction. Our results indicate that PKN is a therapeutic target for cardiac fibrosis in heart failure.

26 April 2024 in Medicine
Verified
Journal Article
Open access
HHHiroaki Hiraiwa
Hiroaki Hiraiwa
DKDaisuke Kasugai
Daisuke Kasugai
TOTakahiro Okumura
Takahiro Okumura
TMToyoaki Murohara
Toyoaki Murohara
Sepsis is caused by the body’s dysregulated response to infection, which can lead to multiorgan injury and death. Patients with sepsis may develop acute cardiac dysfunction, termed septic cardiomyopathy, which is a global but reversible dysfunction of both sides of the heart. This narrative review discusses the mechanistic changes in the heart during septic cardiomyopathy, its diagnosis, existing treatment options regarding severity and course, and emerging treatment approaches. Although no standardized definition for septic cardiomyopathy exists, it is described as a reversible myocardial dysfunction that typically resolves within 7 to 10 days. Septic cardiomyopathy is often diagnosed based on electrocardiography, cardiac magnetic resonance imaging, biomarkers, and direct invasive and noninvasive measures of cardiac output. Presently, the treatment of septic cardiomyopathy is similar to that of sepsis, primarily focusing on acute interventions. Treatments for cardiomyopathy often include angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and diuretics. However, because of profound hypotension in sepsis, many cardiomyopathy treatments are contraindicated in patients with septic cardiomyopathy. Substantial efforts have been made to study the pathophysiological mechanisms and diagnostic options; however, the lack of a uniform definition for septic cardiomyopathy is challenging for physicians when considering treatments. Another challenge for physicians is that the treatment for septic cardiomyopathy has only focused on acute intervention, whereas the treatment for other cardiomyopathies has been provided on a long-term basis. A better understanding of the underlying mechanisms of septic cardiomyopathy may contribute to the development of a unified definition of the condition and novel treatment options.

20 January 2021 in ESC Heart Failure
Verified
Journal Article
Open access
PDF file
YKYuki Kimura
Yuki Kimura
TOTakahiro Okumura
Takahiro Okumura
RMRyota Morimoto
Ryota Morimoto
SKShingo Kazama
Shingo Kazama
NSNaoki Shibata
Naoki Shibata
TMToyoaki Murohara
Toyoaki Murohara
Aims Left ventricular reverse remodelling (LVRR) is a well‐established predictor of a good prognosis in patients with dilated cardiomyopathy (DCM). The prediction of LVRR is important when developing a long‐term treatment strategy. This study aimed to assess the clinical predictors of LVRR and establish a scoring system for predicting LVRR in patients with DCM that can be used at any institution. Methods and results We consecutively enrolled 131 patients with DCM and assessed the clinical predictors of LVRR. LVRR was defined as an absolute increase in left ventricular ejection fraction (LVEF) from ≥10% to a final value of >35%, accompanied by a decrease in left ventricular end‐diastolic dimension (LVEDD) ≥ 10% on echocardiography at 1 ± 0.5 years after a diagnosis of DCM. The mean patient age was 50.1 ± 11.9 years. The mean LVEF was 32.2 ± 9.5%, and the mean LVEDD was 64.1 ± 12.5 mm at diagnosis. LVRR was observed in 45 patients (34%) at 1 ± 0.5 years. In a multivariate analysis, hypertension [odds ratio (OR): 6.86; P = 0.002], no family history of DCM (OR: 10.45; P = 0.037), symptom duration <90 days (OR: 6.72; P < 0.001), LVEF <35% (OR: 13.66; P < 0.0001), and QRS duration 5 in receiver‐operating characteristic curve analysis (area under the curve: 0.89; P < 0.0001; sensitivity: 87%; specificity: 78%). An LVRR predicting score of >5 was an independent predictor compared with the presence of late gadolinium enhancement on cardiovascular magnetic resonance or the severity of fibrosis on endomyocardial biopsy (OR: 11.79; 95% confidence interval: 2.40–58.00; P = 0.002). Conclusions The LVRR predicting score using five predictors including hypertension, no family history of DCM, symptom duration <90 days, LVEF <35%, and QRS duration <116 ms can stratify the LVRR rate in patients with DCM. The LVRR predicting score may be a useful clinical tool that can be used easily at any institution.