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Dive into the research topics where Sari Imamura is active.

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Featured researches published by Sari Imamura.


Journal of Atherosclerosis and Thrombosis | 2015

Unexpectedly High Prevalence of Acquired von Willebrand Syndrome in Patients with Severe Aortic Stenosis as Evaluated with a Novel Large Multimer Index

Toshihiro Tamura; Hisanori Horiuchi; Masao Imai; Tomohisa Tada; Hiroki Shiomi; Maiko Kuroda; Shunsuke Nishimura; Yusuke Takahashi; Yusuke Yoshikawa; Akira Tsujimura; Masashi Amano; Yukiko Hayama; Sari Imamura; Naoaki Onishi; Yodo Tamaki; Soichiro Enomoto; Makoto Miyake; Hirokazu Kondo; Kazuaki Kaitani; Chisato Izumi; Takeshi Kimura; Yoshihisa Nakagawa

AIMnSevere gastrointestinal bleeding sometimes occurs in patients with aortic stenosis (AS), known as Heydes syndrome. This syndrome is thought to be caused by acquired von Willebrand syndrome and is characterized by reduced large von Willebrand factor (vWF) multimers. However, the relationship between the severity of AS and loss of large vWF multimers is unclear.nnnMETHODSnWe examined 31 consecutive patients with severe AS. Quantitative evaluation for loss of large vWF multimers was performed using the conventional large vWF ratio and novel large vWF multimer index. This novel index was defined as the ratio of large multimers of patients to those of controls.nnnRESULTSnLoss of large vWF multimers, defined as the large vWF multimer index <80%, was detected in 21 patients (67.7%). The large vWF multimer ratio and the large vWF multimer index were inversely correlated with the peak aortic gradient (R = -0.58, p=0.0007, and R=-0.64, p<0.0001, respectively). Anemia defined as hemoglobin <9.0 g/dl was observed in 12 patients (38.7%), who were regarded as Heydes syndrome. Aortic valve replacement was performed in 7 of these patients, resulting in the improvement of anemia in all patients from a hemoglobin concentration of 7.5±1.0 g/dl preoperatively to 12.4±1.3 g/dl postoperatively (p<0.0001).nnnCONCLUSIONSnAcquired von Willebrand syndrome may be a differential diagnosis in patients with AS with anemia. The prevalence of AS-associated acquired von Willebrand syndrome is higher than anticipated.


Circulation | 2016

Predictors of Rapid Progression and Clinical Outcome of Asymptomatic Severe Aortic Stenosis.

Shunsuke Nishimura; Chisato Izumi; Masataka Nishiga; Masashi Amano; Sari Imamura; Naoaki Onishi; Yodo Tamaki; Soichiro Enomoto; Makoto Miyake; Toshihiro Tamura; Hirokazu Kondo; Kazuaki Kaitani; Yoshihisa Nakagawa

BACKGROUNDnThe optimal timing of aortic valve replacement (AVR) is controversial in patients with asymptomatic severe aortic stenosis (AS) except when very severe. Prediction of progression of severe AS is helpful in deciding on the timing of AVR. The purpose of this study was to clarify the predictors of progression rate and clinical outcomes of severe AS.nnnMETHODSANDRESULTSnWe retrospectively investigated 140 consecutive patients with asymptomatic severe AS (aortic valve area [AVA], 0.75-1.0 cm(2)). First-year progression rate and annual progression rate of AVA and of aortic jet velocity (AV-Vel) were calculated. Cardiac events were examined and the predictors of rapid progression and cardiac events were analyzed. The median follow-up period was 36 months. The median annual progression rate was -0.05 cm(2)/year for AVA and 0.22 m/s/year for AV-Vel. Dyslipidemia, moderate-severe calcification, and first-year AV-Vel progression ≥0.22 m/s/year were independent predictors of cardiac events. Cardiac event-free rate was lower in patients with AV-Vel first-year progression rate ≥0.22 m/s/year than in those with a lower rate. Diabetes and moderate-severe calcification were related to first-year rapid progression.nnnCONCLUSIONSnThe annual progression rate of severe AS was -0.05 cm(2)/year for AVA and 0.22 m/s/year for AV-Vel. Patients with first-year rapid progression or severely calcified aortic valve should be carefully observed while considering an early operation. (Circ J 2016; 80: 1863-1869).


Internal Medicine | 2016

Multiple Coronary Artery Aneurysms and Thoracic Aortitis Associated with IgG4-related Disease

Shunsuke Nishimura; Masashi Amano; Chisato Izumi; Maiko Kuroda; Yusuke Yoshikawa; Yusuke Takahashi; Sari Imamura; Naoaki Onishi; Yodo Tamaki; Soichiro Enomoto; Makoto Miyake; Toshihiro Tamura; Hirokazu Kondo; Kazuaki Kaitani; Yoshihisa Nakagawa

A 60-year-old man was admitted due to the onset of right coronary artery (RCA) aneurysms. Coronary angiography showed two RCA aneurysms and focal stenosis with limitations in the blood flow. Balloon angioplasty was performed. However, the follow-up coronary angiography showed restenosis, an enlarged proximal aneurysm and a newly formed aneurysm. The serum immunoglobulin G4 level was elevated to 1,350 mg/dL and fluorodeoxyglucose positron emission tomography showed increased uptake in the ascending aorta, so the patient was diagnosed with immunoglobulin G4-related vascular disease. The prevention of further enlargement of the aneurysms and an improvement in the RCA flow were achieved with steroid therapy. Steroid therapy may therefore be effective for immunoglobulin G4-related vascular disease.


International Journal of Cardiology | 2017

Actual management and prognosis of severe isolated tricuspid regurgitation associated with atrial fibrillation without structural heart disease

Yusuke Takahashi; Chisato Izumi; Makoto Miyake; Miyako Imanaka; Maiko Kuroda; Shunsuke Nishimura; Yusuke Yoshikawa; Masashi Amano; Sari Imamura; Naoaki Onishi; Yodo Tamaki; Soichiro Enomoto; Toshihiro Tamura; Hirokazu Kondo; Kazuaki Kaitani; Yoshihisa Nakagawa

BACKGROUNDnPatients with atrial fibrillation (AF) without structural heart diseases can show severe tricuspid regurgitation (TR), especially among aged people. The aim of this study was to clarify the actual management, prognosis, and prognostic factors for severe isolated TR associated with AF without structural heart diseases.nnnMETHODS AND RESULTSnWe retrospectively investigated actual management in 178 consecutive patients with severe isolated TR associated with AF between 1999 and 2011 in our institution. Prognosis and its predictors were also investigated in 115 patients (68 persistent TR and 47 transient TR) who were followed-up for >1year. During the follow-up period (mean: 5.9years), event free rate from death due to right-sided heart failure (RHF) was 97% at 5years. Persistent TR was associated with higher risk of hospitalization due to RHF than transient TR (log-rank P=0.048) and death due to RHF were all seen in patients with persistent TR who experienced hospitalization due to RHF. Among patients with persistent TR, right ventricular outflow tract dimension >35.3mm, right atrial area >40.3cm2, and tenting height >2.1mm were associated with higher risk of hospitalization due to RHF (adjusted hazard ratio: 3.32, 3.83, and 2.89, respectively; P=0.003, 0.002, and 0.009, respectively).nnnCONCLUSIONnThe prognosis of severe isolated TR associated with AF was good with a focus on cardiac death. However, the incidence of cardiac death increased among patients who experienced hospitalization due to RHF. Larger right ventricular outflow tract dimension, right atrial area and tenting height were predictors of hospitalization due to RHF.


Heart and Vessels | 2016

Relationship between diastolic ventricular dysfunction and subclinical sleep-disordered breathing in atrial fibrillation ablation candidates

Kazuaki Kaitani; Hirokazu Kondo; Koji Hanazawa; Naoaki Onishi; Yukiko Hayama; Akira Tsujimura; Maiko Kuroda; Shunsuke Nishimura; Yusuke Yoshikawa; Yusuke Takahashi; Masashi Amano; Sari Imamura; Yodo Tamaki; Soichiro Enomoto; Makoto Miyake; Toshihiro Tamura; Makoto Motooka; Chisato Izumi; Yoshihisa Nakagawa

Sleep-disordered breathing (SDB) is recognized as a primary factor or mediator of atrial fibrillation (AF). We hypothesized that the severity of SDB among AF ablation candidates would be associated with left ventricular diastolic dysfunction (LVDD) even for subclinical SDB. A total of 246 patients hospitalized for initial pulmonary vein isolation (PVI) were analyzed. Known SDB cases were excluded. We measured the oxygen desaturation index (ODI) by pulse oximetry overnight as an indicator of SDB, and classified SDB severity by 3xa0% ODI as normal (ODIxa0<xa05 events/h), mild (ODIxa0≤xa05 to <15 events/h), or moderate-to-severe (ODIxa0≥15 events/h). The LVDD was assessed by echocardiography using combined categories with tissue Doppler imaging and left atrial (LA) volume measurement. Among the participants, 42 patients (17.1xa0%) had LVDD. The prevalence of LVDD increased with the SDB severity from 8.6xa0% (normal) to 12.7xa0% (mild) to 40.0xa0% (moderate-to-severe SDB) (pxa0<xa00.0001). In the multivariate logistic regression analysis, the odds ratio of having LVDD in the moderate-to-severe SDB group (ODIxa0≥xa015) vs. normal group (ODIxa0<xa05) was 5.96 (95xa0% CI, 2.10–19.00, Pxa0=xa00.006). The presence of moderate-to-severe SDB in AF ablation candidates adversely affected LV diastolic function even during a subclinical state of SDB.


Journal of Cardiology | 2017

Diagnostic accuracy of the Embolic Risk French Calculator for symptomatic embolism with infective endocarditis among Japanese population

Yusuke Takahashi; Chisato Izumi; Makoto Miyake; Miyako Imanaka; Maiko Kuroda; Shunsuke Nishimura; Yusuke Yoshikawa; Masashi Amano; Sari Imamura; Naoaki Onishi; Yodo Tamaki; Soichiro Enomoto; Toshihiro Tamura; Hirokazu Kondo; Kazuaki Kaitani; Kazuo Yamanaka; Yoshihisa Nakagawa

BACKGROUNDnRecently, the Embolic Risk French Calculator (ER-Calculator) was designed to predict symptomatic embolism (SE) associated with infective endocarditis (IE), but external validation has not been reported. This study aimed to determine predictors of SE and the diagnostic accuracy of the ER-Calculator in left-sided active IE among a Japanese population.nnnMETHODSnThis retrospective cohort study included 166 consecutive patients with a definite diagnosis of left-sided IE from 1994 to 2015 in our institution. SE during the period after initiation of antibiotic therapy was defined as new SE and embolism during the period before initiation of antibiotic therapy was defined as previous embolism. The primary endpoint was new SE.nnnRESULTSnThe mean age of patients was 63±17 years. New SE occurred in 23 (14%) patients at a median of 6 days (interquartile range: 2.5-12.5 days) after initiation of antibiotic therapy. The cumulative incidence of new SE at 12 weeks was 18.2%. The 2-week probability by the ER-Calculator as well as previously reported predictors, such as previous embolism, vegetation length (>10mm), and their combination, were associated with a high risk of new SE. By receiver operating characteristic analysis, the area under the curve of the 2-week probability by the ER-Calculator for prediction of new SE was 0.75 and the optimal cut-off value was 8%. A 2-week probability >8% by the ER-Calculator was the most useful predictor of new SE (hazard ratio 3.63, 95% confidence interval 1.50-8.37; p=0.006), which was more remarkable for fatal embolic events (hazard ratio 13.9, 95% confidence interval 3.19-95.4; p=0.004).nnnCONCLUSIONSnThe ER-Calculator is a useful predictor of new SE. Predictive ability is more remarkable for critical embolic events.


Circulation | 2017

Long-Term Clinical Outcomes and Prognostic Factors After Pericardiectomy for Constrictive Pericarditis in a Japanese Population

Shunsuke Nishimura; Chisato Izumi; Masashi Amano; Sari Imamura; Naoaki Onishi; Yodo Tamaki; Soichiro Enomoto; Makoto Miyake; Toshihiro Tamura; Hirokazu Kondo; Kazuaki Kaitani; Kazuo Yamanaka; Yoshihisa Nakagawa

BACKGROUNDnConstrictive pericarditis (CP) is characterized by impaired diastolic cardiac function leading to heart failure. Pericardiectomy is considered effective treatment for CP, but data on long-term clinical outcomes after pericardiectomy are limited.Methodsu2004andu2004Results:We retrospectively investigated 45 consecutive patients (mean age, 59±14 years) who underwent pericardiectomy for CP. Preoperative clinical factors, parameters of cardiac catheterization, and cardiac events were examined. Cardiac events were defined as hospitalization owing to heart failure or cardiac death.Median follow-up was 5.7 years. CP etiology was idiopathic in 16 patients, post-cardiac surgery (CS) in 21, tuberculosis-related in 4, non-tuberculosis infection-related in 2, infarction-related in 1, and post-radiation in 1. The 5-year event-free survival was 65%. Patients with idiopathic CP and tuberculosis-related CP had favorable outcomes compared with post-CS CP (5-year event-free survival: idiopathic, 80%; tuberculosis, 100%; post-CS, 52%). Higher age (hazard ratio: 2.51), preoperative atrial fibrillation (3.25), advanced New York Heart Association class (3.92), and increased pulmonary artery pressure (1.06) were predictors of cardiac events. Patients with postoperative right-atrial pressure ≥9 mmHg had lower event-free survival than those with right-atrial pressure <9 mmHg (39% vs. 75% at 5 years, P=0.013).nnnCONCLUSIONSnLong-term clinical outcomes after pericardiectomy among a Japanese population were related to the underlying etiology and the patients preoperative clinical condition. Postoperative cardiac catheterization may be helpful in the prediction of prognosis after pericardiectomy.


Heart | 2016

Progression of aortic regurgitation after subpulmonic infundibular ventricular septal defect repair

Masashi Amano; Chisato Izumi; Sari Imamura; Naoaki Onishi; Yodo Tamaki; Soichiro Enomoto; Makoto Miyake; Toshihiro Tamura; Hirokazu Kondo; Kazuaki Kaitani; Kazuo Yamanaka; Yoshihisa Nakagawa

Objective In patients with subpulmonic infundibular ventricular septal defect (VSD), postoperative progression of aortic regurgitation (AR) sometimes occurs despite early operation before the development of AR. The present study was aimed to identify the occurrence rate and predictors of late AR progression after VSD repair alone. Methods We retrospectively investigated 91 consecutive patients who underwent subpulmonic infundibular VSD repair alone and were followed up with echocardiography for >3u2005years postoperatively. The clinical backgrounds and chronological changes in postoperative AR were evaluated. Results The median follow-up period after VSD repair was 13.4u2005years. Among 91 patients, 7 patients showed postoperative AR progression (AR progression group) and 84 patients did not (No AR progression group). No patient in AR progression group revealed more than moderate AR preoperatively. The incidence of postoperative VSD leakage was significantly higher in AR progression group than No AR progression group (43.0% vs 2.4%, respectively; p<0.01). No significant differences were present in sex, age, preoperative AR severity, VSD diameter or rate of cusp herniation. All patients in AR progression group showed deformity of the right coronary cusp or leaflet, resulting in AR progression. Conclusions Among patients with subpulmonic infundibular VSD, the incidence of late AR progression after VSD repair alone was unexpectedly high (7.7%). Postoperative VSD leakage may be a significant risk factor for late AR progression. Long-term follow-up of postoperative AR is needed even for patients who undergo VSD repair alone.


Heart and Vessels | 2018

Relationship between left ventricular diastolic dysfunction and very late recurrences after multiple procedures for atrial fibrillation ablation.

Naoaki Onishi; Kazuaki Kaitani; Masashi Amano; Sari Imamura; Jiro Sakamoto; Yodo Tamaki; Soichiro Enomoto; Makoto Miyake; Toshihiro Tamura; Hirokazu Kondo; Chisato Izumi; Yoshihisa Nakagawa

Although very late recurrences (VLRs) (first recurrence >12xa0months after the last catheter ablation) of atrial fibrillation (AF) after multiple catheter ablation procedures are rare, it remains a critical issue. The risk factors for VLRs remain largely unclear. From December 2011 to April 2014, 253 patients underwent an initial catheter ablation. Of the 253 patients, 21 had AF recurrences within 1xa0year after the last catheter ablation. The study was conducted in the remaining 232 patients. Left ventricular diastolic dysfunction (LVDD) was assessed by echocardiography using composite categories with tissue Doppler imaging and left atrial volume measurements, i.e., a septal e′xa0<xa08xa0cm/s, lateral e′xa0<xa010xa0cm/s, and left atrium volume index (LAV/body surface area) (LAVI) ≥34xa0mL/m2. LVDD was observed in 40 patients. Sinus rhythm was preserved in 220 patients after multiple catheter procedures, and 12 had VLRs. The clinical factors possibly related to VLRs were examined, and a multivariate regression analysis showed that LVDD was the only independent risk factor for VLRs (hazard ratio: 10.31, 95% confidence interval: 2.78–38.18, Pxa0<xa00.0001). LVDD at baseline is a risk factor for a VLR after multiple catheter ablation procedures for AF.


International Journal of Cardiology | 2016

Late recurrence of left ventricular dysfunction after aortic valve replacement for severe chronic aortic regurgitation

Masashi Amano; Chisato Izumi; Sari Imamura; Naoaki Onishi; Yodo Tamaki; Soichiro Enomoto; Makoto Miyake; Toshihiro Tamura; Hirokazu Kondo; Kazuaki Kaitani; Kazuo Yamanaka; Yoshihisa Nakagawa

BACKGROUNDnAortic valve replacement (AVR) for chronic aortic regurgitation (AR) with a decreased ejection fraction (EF) leads to improvement in left ventricular (LV) function, but there are no reports on late recurrence of LV dysfunction over long-term after AVR. This study aimed to identify frequency and predictors of late recurrent LV dysfunction after AVR.nnnMETHODSnWe retrospectively investigated 58 consecutive patients undergoing AVR for severe chronic AR and with follow-up echocardiography for >5years after AVR. Late recurrence of LV dysfunction was defined as an EF of <50% late after AVR and a 10% reduction in the EF compared with that observed at 1year after AVR.nnnRESULTSnThe mean follow-up period was 10.3±5.2years. The preoperative EF was <50% in 21 (36%) patients, but it was normalized at 1year after AVR in all patients except for one. However, late recurrence of LV dysfunction developed in 7 (12%) of the 58 patients. These patients showed significantly higher LV end-diastolic and end-systolic diameters before and at 1year after AVR, a lower EF and relative wall thickness before AVR, a higher LV mass index at 1year after AVR, and a higher incidence of preoperative and postoperative atrial fibrillation than those without late recurrence.nnnCONCLUSIONSnLate recurrent LV dysfunction may occur after AVR for severe chronic AR despite EF being once normalized. Early surgery proceeding remarkable LV enlargement and maintaining sinus rhythm are important for LV function over the long-term after AVR.

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