Harutoshi Tamura

Dr. Harutoshi Tamura

orcid

Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

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

Representative Publications

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25 July 2019 in Circulation Journal
Verified
Journal Article
Open access
PDF file
MSMike Saji
Mike Saji
TTTetsuya Tobaru
Tetsuya Tobaru
RHRyosuke Higuchi
Ryosuke Higuchi
KMKeitaro Mahara
Keitaro Mahara
ITItaru Takamisawa
Itaru Takamisawa
MIMitsuaki Isobe
Mitsuaki Isobe
Background:The purpose of this study was to investigate if the transcatheter aortic valve replacement (TAVR) risk score can independently predict outcomes following TAVR, and to evaluate its predictive performance.Methods and Results:This retrospective multicenter study comprised 682 patients with severe aortic stenosis who underwent TAVR. The primary endpoint was all-cause death following TAVR. The clinical model was established using variables identified as independent predictors in the multivariate analysis. Incremental values were assessed after adding atrial fibrillation, body mass index (BMI), and serum albumin to the TAVR risk score in receiver-operating characteristic analysis. The median TAVR risk score was 2.1% with a mean follow-up of 505 days. On Kaplan-Meier analysis, a TAVR risk score >4% had lowest survival rate, whereas TAVR risk score ≤2% had the highest survival rate at 3 years (log-rank P<0.001). The multivariate Cox regression analysis found the TAVR risk score was independently associated with all-cause death, and demonstrated moderate predictive performance for predicting all-cause death at 3 years. However, if each independent predictor is added to the model, it significantly increased discriminatory performance, particularly with BMI and serum albumin level.Conclusions:We demonstrated that the TAVR risk score could independently predict mid-term death following TAVR, and had greater predictive performance for predicting all-cause death at 3 years with BMI and serum albumin level.

1 July 2012 in Journal of Cardiac Failure
Verified
Journal Article
Closed access
HDHyuma Daidoji
Hyuma Daidoji
TATakanori Arimoto
Takanori Arimoto
JNJoji Nitobe
Joji Nitobe
HTHarutoshi Tamura
Harutoshi Tamura
DKDaisuke Kutsuzawa
Daisuke Kutsuzawa
IKIsao Kubota
Isao Kubota

26 November 2021 in Journal of Clinical Medicine
Verified
Journal Article
Open access
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KWKen Watanabe
Ken Watanabe
TWTetsu Watanabe
Tetsu Watanabe
YOYoichiro Otaki
Yoichiro Otaki
TMTakayo Murase
Takayo Murase
TNTakashi Nakamura
Takashi Nakamura
MWMasafumi Watanabe
Masafumi Watanabe
Xanthine oxidoreductase (XOR) is the rate-limiting enzyme in uric acid (UA) production that plays a pivotal role in generating oxidative stress. Gender differences in the impact of plasma XOR activity on coronary artery spasm (CAS) remain unclear. We investigated plasma XOR activity in 132 patients suspected of having CAS (male, n = 78; female, n = 54) and who underwent an intracoronary acetylcholine provocation test. Plasma XOR activity was significantly lower in female patients compared with male patients. CAS was provoked in 36 male patients and 17 female patients, and both had significantly higher plasma XOR activity than those without. Multivariate logistic regression analysis showed that this activity was independently associated with the incidence of CAS in both sexes after adjusting for confounding factors. The optimal cut-off values for predicting CAS were lower in female patients than in male patients. Multivariate analysis demonstrated that female patients with high XOR activity exhibited a higher incidence of CAS than male patients. Plasma XOR activity was an independent predictor of the incidence of CAS in both sexes. The impact of plasma XOR activity on CAS was stronger in female patients than in male patients.

19 August 2023 in IJC Heart & Vasculature
Verified
Journal Article
Open access
KNKota Nishida
Kota Nishida
MSMike Saji
Mike Saji
RHRyosuke Higuchi
Ryosuke Higuchi
ITItaru Takamisawa
Itaru Takamisawa
MNMamoru Nanasato
Mamoru Nanasato
MIMitsuaki Isobe
Mitsuaki Isobe
Information regarding the outcomes of transcatheter aortic valve replacement (TAVR) in men is limited. This study aimed to investigate short- to mid-term outcomes and prognostic predictors in this population. The data of 519 men were analyzed from 1,693 consecutive patients with symptomatic severe aortic stenosis who underwent TAVR at six hospitals between April 2010 and July 2020. The primary endpoint was all-cause mortality at 30 days after TAVR. The mean age and Society of Thoracic Surgeons (STS) score were 83.7 ± 5.9 years and 6.3 ± 4.7%, respectively. Overall, 23.5% of patients consumed alcohol with a frequency of > 1 drinks/week, and 12.1% consumed alcohol with a frequency of > 8 drinks/week, while 66.1% were former smokers and 4.2% were current smokers. Mortality at 30 days was 0.8%. During the median follow-up period of 448 days, the estimated survival rates at 1 year post-TAVR was 90.7 ± 1.4%. In multivariate analysis, the serum albumin level [hazard ratio (HR): 2.20, 95% confidence interval (CI):1.36–3.62, p = 0.001], atrial fibrillation (HR: 1.79, 95% CI: 1.13–2.82, p = 0.012), and STS score (HR: 1.33, 95% CI: 1.06–1.67, p = 0.015) were independently associated with all-cause mortality following TAVR. Adjusted hazard ratios of current smoking, heavy drinking, and presence of cancer were 1.05 (95% CI: 0.36–2.98),1.37 (95% CI: 0.75–2.48), and 1.13 (95% CI: 0.75–2.48), respectively. Our study demonstrated that serum albumin levels, atrial fibrillation, and STS score were independently associated with all-cause mortality following TAVR in men.

7 December 2020 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
YCYuichi Chikata
Yuichi Chikata
HIHiroshi Iwata
Hiroshi Iwata
SDShinichiro Doi
Shinichiro Doi
TFTakehiro Funamizu
Takehiro Funamizu
SOShinya Okazaki
Shinya Okazaki
TMTohru Minamino
Tohru Minamino
Accurate outcome prediction following transcatheter aortic valve implantation (TAVI) has gained further importance along with expanding its indication to patients with a lower surgical risk. Although previous studies have evaluated the prognostic impacts of gender and atrial fibrillation (AF) in TAVI patients, these two factors have rarely been addressed simultaneously. This retrospective observational study based on a multicenter TAVI registry involved 1088 patients who underwent TAVI between May, 2010 and February, 2020 at 3 hospitals in Japan. Participants were divided into 4 groups by gender and pre-existing AF, such as Female AF (−) (n = 559), Male AF (−) (n = 266), Female AF (+) (n = 187) and Male AF (+) (n = 76). Primary and secondary endpoints were death due to any and cardiovascular cause, and the composite of all-cause death and heart failure hospitalization, respectively. The median follow-up period was 538 days. Cumulative incidences of primary and secondary endpoints were lower in the Female AF (−) group compared to the other 3 groups. Adjusted multivariate Cox proportional hazard analyses showed an independent association of either or both of male gender and AF with adverse outcomes, when compared to the group with none of these (hazard ratios and 95% confidence intervals vs. Female AF (−) (reference) for all-cause death of Male AF (−): 2.7, 1.6–4.6, p < 0.001, Female AF (+): 3.5, 2.1–6.0, p < 0.001, and Male AF (+): 3.9, 1.9–7.8, p < 0.001), while there was no evidence of their synergistic prognostic impact. Male gender and being complicated by AF independently, but not synergistically, predicted poor long-term outcomes in patients undergoing TAVI.

16 January 2023 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
TKTakuma Koike
Takuma Koike
HIHiroshi Iwata
Hiroshi Iwata
YCYuichi Chikata
Yuichi Chikata
SDShinichiro Doi
Shinichiro Doi
RNRyo Naito
Ryo Naito
TMTohru Minamino
Tohru Minamino
Pulmonary hypertension (PH) is a common complication of aortic stenosis (AS). Despite the established association between PH and poor outcomes in patients with AS, the prognostic implication of a change in PH after transcatheter aortic valve implantation (TAVI) has been rarely evaluated. This study analyzed a prospective multi-center TAVI registry database involving six Japanese centers and used the transtricuspid pressure gradient (TRPG) obtained by echocardiography to estimate pulmonary artery systolic pressure. The participants (n = 2056) were first divided into two groups by TRPG before TAVI, a PH (−) group (TRPG < 30 mmHg) (n = 1407, 61.9%) and a PH (+) group (TRPG ≥ 30 mmHg) (n = 649, 28.6%). Next, by TRPG after (4.1 ± 5.3 days) TAVI, the PH (+) group was further subdivided into two groups, Recovered PH (TRPG < 30 mmHg, n = 253) and Persistent PH (TRPG after TAVI ≥ 30 mmHg, n = 396). The median follow-up duration was 1.8 years. The primary and secondary endpoints were the composite and each of cardiovascular (CV) death and heart failure hospitalization, respectively. Unadjusted Kaplan-Meier estimates with log-rank comparisons showed significantly higher cumulative incidences of primary and secondary endpoints in the Persistent PH group compared to other groups. Moreover, adjusted multivariate Cox-proportional hazard analyses showed that a decreased (−10 mmHg) TRPG after TAVI was linearly associated with a reduced risk of the primary endpoint (hazard ratio (HR): 0.76, 95% confidence interval (CI): 0.64–0.90, p = 0.0020). The findings in the present study indicate that the recovery of PH may partly contributes to the prognostic benefit of TAVI procedure in patients with AS and elevated pulmonary artery systolic pressure.