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Featured researches published by Ryota Kakizaki.


International Heart Journal | 2018

Endothelial Dysfunction Is Associated with Cognitive Impairment of Elderly Cardiovascular Disease Patients: A Reactive Hyperemia-Peripheral Arterial Tonometry Study

Kazuhiro Fujiyoshi; Minako Yamaoka-Tojo; Yoshiyasu Minami; Toshiki Kutsuna; Shinichi Obara; Ryota Kakizaki; Teruyoshi Nemoto; Takuya Hashimoto; Sayaka Namba; Takao Shimohama; Taiki Tojo; Junya Ako

Cognitive impairment is frequently represented in elderly patients with cardiovascular disease (CVD); yet, the mechanism is uncertain. Recent studies have suggested the association between the vascular endothelial dysfunction and cognitive impairment. The aim of this study was to clarify the association between endothelial dysfunction and cognitive impairment in elderly patients with CVD.A total of 80 elderly patients (> 70 years old) with CVD were included. Patients who had already pharmacologically intervened for cognitive impairment were excluded. The endothelial dysfunction was assessed by the reactive hyperemia-peripheral arterial tonometry (RH-PAT). Cognitive impairment was diagnosed by the Mini-mental state examination.The RH-PAT index was significantly lower in cognitive impairment (median 1.60 [interquartile range (IQR) 1.34 to 1.89], n = 51) as compared with non-cognitive impairment (median 1.75 [IQR 1.55 to 2.30], n = 29, P = 0.005). By a multivariate analysis, the RH-PAT index was independently associated with cognitive impairment (odds ratio: 0.89; 95% confidence interval: 0.81 to 0.97; per 0.1, P = 0.044). In the receiver-operating characteristic analysis, the best cut-off of the RH-PAT index to identify cognitive impairment was 1.65 (area under the curve 0.67; P = 0.011) with limited the sensitivity (63%) and specificity (66%).A lower RH-PAT index was significantly associated with the presence of cognitive impairment in elderly CVD patients. Further studies are required to clarify the mechanism and the causal relationship between the endothelial dysfunction and cognitive impairment in patients with CVD.


Heart Surgery Forum | 2018

Early Safety and Efficacy of Sapien 3 20 mm Transcatheter Heart Valve Implantation in Small Japanese Body Size

Kentaro Meguro; Ryota Kakizaki; Takuya Hashimoto; Tomoyoshi Yanagisawa; Toshimi Koitabashi; Tadashi Kitamura; Junya Ako

BACKGROUND Transcatheter aortic valve implantation (TAVI) is effective in treating severe aortic stenosis in inoperable or high-risk surgical patients, however, the little is known about outcomes after Sapien 3 20 mm transcatheter heart valve (THV) implantation. The purpose of this study was to investigate the short term outcomes of Sapien 3 20 mm THV implantation in Japanese people with a small body size. METHODS We retrospectively collected the hospital records of consecutive patients who underwent TAVI using the Sapien 3 20 mm THV between October 2016 and March 2017. Clinical and echocardiographic data from before and one week after TAVI were collected. RESULTS Six Japanese patients (all female, mean age 89 ± 5 years, body surface area [BSA] 1.29 ± 0.16m2) received a Sapien 3 20 mm THV. All the procedures were feasible and successful, and the 30-day mortality rate was 0%. The functional class and the echocardiographic findings significantly improved (aortic valve area, 0.5 ± 0.1 cm2 to 0.8 ± 0.1cm2; mean pressure gradient, 55 ± 15 mmHg to 19 ± 7 mmHg; P = .043, respectively). However, the values of the indexed effective orifice area in all patients after Sapien 3 20 mm THV implantation were less than 0.85 cm2/m2, suggesting prosthesis-patient mismatch (PPM). CONCLUSIONS The implantation of a Sapien 3 20 mm THV was safe and effective in high surgical risk elderly Japanese patients with a small body size. PPM after Sapien 3 20mm THV may be prevalent among Asians with small body sizes. Careful clinical follow-up will be necessary after Sapien 3 20 mm THV implantation.


Journal of Cardiology Cases | 2017

Untreated cardiac sarcoidosis with active inflammation: Severe left ventricular dysfunction and ventricular wall thinning in three years

Ryota Kakizaki; Toshimi Koitabashi; Yoshiyasu Minami; Takeru Nabeta; Toyoji Kaida; Shunsuke Ishii; Emi Maekawa; Takayuki Inomata; Junya Ako

A 74-year-old female was admitted for the treatment of complete atrioventricular block. Echocardiography showed thickening of interventricular septum and a slight thinning in the basal region with normal left ventricular (LV) function. She was clinically diagnosed with cardiac sarcoidosis accompanied by active inflammation from the findings of blood test, nuclear scanning, and magnetic resonance imaging. After pacemaker implantation, we recommended corticosteroid therapy, which she refused for the fear of side effects. Three years later, she was re-admitted to our hospital due to heart failure. Echocardiography showed severe LV systolic dysfunction and dilatation with wall thinning. Even though we started corticosteroid therapy and continued it for one year, LV function was not improved. In patients with cardiac sarcoidosis accompanied by active inflammation, LV dysfunction, and dilatation may rapidly progress. Early diagnosis and treatment with corticosteroid may be important to preserve cardiac function. <Learning objective: Left ventricular (LV) dysfunction in patients with cardiac sarcoidosis accompanied by active inflammation may rapidly progress in a short period. Corticosteroid therapy is demonstrated to improve the long-term clinical outcome, however, it may not be effective once LV function is worsened with wall thinning. Early diagnosis and treatment with corticosteroid may be important to preserve cardiac function in patients with cardiac sarcoidosis accompanied by active inflammation.>.


Journal of Atherosclerosis and Thrombosis | 2017

Lower Level of Low Density Lipoprotein Cholesterol is Associated with a Higher Increase in the Fractional Flow Reserve in Patients with Fixed-dose Rosuvastatin

Takehiro Hashikata; Taiki Tojo; Yusuke Muramatsu; Toshimitsu Sato; Ryota Kakizaki; Teruyoshi Nemoto; Kazuhiro Fujiyoshi; Sayaka Namba; Lisa Kitasato; Takuya Hashimoto; Ryo Kameda; Takao Shimohama; Minako Yamaoka-Tojo; Junya Ako

Aim: Fractional flow reserve (FFR) reflects on the diffuse atherosclerosis per coronary artery. It is unknown whether the statin therapy affects long term FFR after stenting. The aim of this study was to evaluate the long term FFR after stent implantation in patients who are intaking fixed-dose rosuvastatin. Methods: A total of 22 patients with stable angina pectoris were enrolled. The values of FFR were measured before, immediately after, and 18 months after (follow-up day) the implantation of everolimus eluting stent (EES; Promus Element™ or Promus Element Plus™). A fixed dose of rosuvastatin at 5 mg/day was administrated to all patients. Results: Of the 22 patients, 2 were excluded because of adverse effect of rosuvastatin and in-stent total occlusion after EES implantation. Overall, the values of FFR immediately after and 18 months after EES implantation did not show significant change (from 0.90 ± 0.05 to 0.88 ± 0.06, p = 0.16). However, there was a significant negative correlation between low density lipoprotein (LDL) cholesterol level at follow-up day and changes in the value of FFR (p = 0.01, r = −0.74). There was an increase in the FFR value after stenting in 8 out of 9 patients with LDL cholesterol level below 75 mg/dl (area under the curve 0.92, p = 0.0005). Conclusions: LDL cholesterol level was associated with the change in the FFR value in patients following stent implantation. Lower LDL cholesterol tended to improve in the long-term FFR, underscoring the importance of lowering LDL cholesterol to prevent the progression of coronary atherosclerosis.


Clinical Case Reports | 2017

Myocardial ischemia induced by major aortopulmonary collateral arteries treated with transcatheter coil embolization

Ryota Kakizaki; Taiki Tojo; Yoshiyasu Minami; Toshimi Koitabashi; Reiko Woodhams; Takao Shimohama; Masahiro Ishii; Junya Ako

Major aortopulmonary collateral arteries branching from coronary arteries may cause coronary steal. The careful follow‐up is needed irrespective of symptoms because increasing physical activities and oxygen demand along with the age may induce myocardial ischemia. Transcatheter intervention by well‐trained physician would be a treatment option in patients with myocardial ischemia.


Circulation | 2017

Localized Inflammation and Aneurysm Formation 10 Years After Sirolimus-Eluting Stent Implantation

Takeru Nabeta; Takehiro Hashikata; Taiki Tojo; Ryota Kakizaki; Yoshiyasu Minami; Kentaro Meguro; Takao Shimohama; Shigeru Suzuki; Yusuke Inoue; Junya Ako

and cilostazol at 200 mg/day for 10 years. As part of thorough examination of atrioventricular block, 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) was performed to rule out cardiac sarcoidosis. There was no myocardial FDG uptake, but there was a significant uptake around the SES in the LAD (Figure 1). Coronary CT angiography showed aneurysmal dilatation (18×28 mm) with a low-density area surrounding the SES (Figure 2A). Coronary angiography A 63-year-old woman was admitted for the treatment of sick sinus syndrome and atrioventricular block. She had received sirolimus-eluting stent (SES; 2.5×18 mm) in the left anterior descending artery (LAD) 10 years previously. Routine coronary angiography had indicated no stent restenosis 1 year after SES implantation. The patient had a history of hyperlipidemia and hypertension, and coronary risk factors were well controlled after the stenting. She continued taking aspirin at 100 mg/day


Heart and Vessels | 2016

Teneligliptin improves left ventricular diastolic function and endothelial function in patients with diabetes

Takehiro Hashikata; Minako Yamaoka-Tojo; Ryota Kakizaki; Teruyoshi Nemoto; Kazuhiro Fujiyoshi; Sayaka Namba; Lisa Kitasato; Takuya Hashimoto; Ryo Kameda; Emi Maekawa; Takao Shimohama; Taiki Tojo; Junya Ako


Heart and Vessels | 2017

Erratum to: Effects on bone metabolism markers and arterial stiffness by switching to rivaroxaban from warfarin in patients with atrial fibrillation

Sayaka Namba; Minako Yamaoka-Tojo; Ryota Kakizaki; Teruyoshi Nemoto; Kazuhiro Fujiyoshi; Takehiro Hashikata; Lisa Kitasato; Takuya Hashimoto; Ryo Kameda; Kentaro Meguro; Takao Shimohama; Taiki Tojo; Junya Ako


Heart and Vessels | 2017

Ezetimibe enhances and stabilizes anticoagulant effect of warfarin

Takehiro Hashikata; Minako Yamaoka-Tojo; Ryota Kakizaki; Teruyoshi Nemoto; Kazuhiro Fujiyoshi; Sayaka Namba; Lisa Kitasato; Takuya Hashimoto; Shunsuke Ishii; Ryo Kameda; Takao Shimohama; Taiki Tojo; Junya Ako


International Journal of Cardiology | 2016

Cardiac resynchronization therapy reduces left ventricular energy loss

Ryota Kakizaki; Takeru Nabeta; Shunsuke Ishii; Toshimi Koitabashi; Keiichi Itatani; Takayuki Inomata; Junya Ako

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