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Dive into the research topics where Akihiro Komasa is active.

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Featured researches published by Akihiro Komasa.


Journal of the American College of Cardiology | 2015

Initial Surgical Versus Conservative Strategies in Patients With Asymptomatic Severe Aortic Stenosis.

Tomohiko Taniguchi; Takeshi Morimoto; Hiroki Shiomi; Kenji Ando; Norio Kanamori; Koichiro Murata; Takeshi Kitai; Yuichi Kawase; Chisato Izumi; Makoto Miyake; Hirokazu Mitsuoka; Masashi Kato; Yutaka Hirano; Shintaro Matsuda; Kazuya Nagao; Tsukasa Inada; Tomoyuki Murakami; Yasuyo Takeuchi; Keiichiro Yamane; Mamoru Toyofuku; Mitsuru Ishii; Eri Minamino-Muta; Takao Kato; Moriaki Inoko; Tomoyuki Ikeda; Akihiro Komasa; Katsuhisa Ishii; Kozo Hotta; Nobuya Higashitani; Yoshihiro Kato

BACKGROUND Current guidelines generally recommend watchful waiting until symptoms emerge for aortic valve replacement (AVR) in asymptomatic patients with severe aortic stenosis (AS). OBJECTIVES The study sought to compare the long-term outcomes of initial AVR versus conservative strategies following the diagnosis of asymptomatic severe AS. METHODS We used data from a large multicenter registry enrolling 3,815 consecutive patients with severe AS (peak aortic jet velocity >4.0 m/s, or mean aortic pressure gradient >40 mm Hg, or aortic valve area <1.0 cm(2)) between January 2003 and December 2011. Among 1,808 asymptomatic patients, the initial AVR and conservative strategies were chosen in 291 patients, and 1,517 patients, respectively. Median follow-up was 1,361 days with 90% follow-up rate at 2 years. The propensity score-matched cohort of 582 patients (n = 291 in each group) was developed as the main analysis set for the current report. RESULTS Baseline characteristics of the propensity score-matched cohort were largely comparable, except for the slightly younger age and the greater AS severity in the initial AVR group. In the conservative group, AVR was performed in 41% of patients during follow-up. The cumulative 5-year incidences of all-cause death and heart failure hospitalization were significantly lower in the initial AVR group than in the conservative group (15.4% vs. 26.4%, p = 0.009; 3.8% vs. 19.9%, p < 0.001, respectively). CONCLUSIONS The long-term outcome of asymptomatic patients with severe AS was dismal when managed conservatively in this real-world analysis and might be substantially improved by an initial AVR strategy. (Contemporary Outcomes After Surgery and Medical Treatment in Patients With Severe Aortic Stenosis Registry; UMIN000012140).


Scientific Reports | 2017

Causes of Death in Patients with Severe Aortic Stenosis: An Observational study

Eri Minamino-Muta; Takao Kato; Takeshi Morimoto; Tomohiko Taniguchi; Hiroki Shiomi; Kenji Nakatsuma; Shinichi Shirai; Kenji Ando; Norio Kanamori; Koichiro Murata; Takeshi Kitai; Yuichi Kawase; Makoto Miyake; Chisato Izumi; Hirokazu Mitsuoka; Masashi Kato; Yutaka Hirano; Shintaro Matsuda; Kazuya Nagao; Tsukasa Inada; Tomoyuki Murakami; Yasuyo Takeuchi; Keiichiro Yamane; Mamoru Toyofuku; Mitsuru Ishii; Moriaki Inoko; Tomoyuki Ikeda; Akihiro Komasa; Eiji Tada; Katsuhisa Ishii

Whether patients with severe aortic stenosis (AS) die because of AS-related causes is an important issue for the management of these patients. We used data from CURRENT AS registry, a Japanese multicenter registry, to assess the causes of death in severe AS patients and to identify the factors associated with non-cardiac mortality. We enrolled 3815 consecutive patients with a median follow-up of 1176 days; the 1449 overall deaths comprised 802 (55.3%) from cardiac and 647 (44.7%) from non-cardiac causes. Heart failure (HF) (25.7%) and sudden death (13.0%) caused the most cardiac deaths, whereas infection (13.0%) and malignancy (11.1%) were the main non-cardiac causes. According to treatment strategies, infection was the most common cause of non-cardiac death, followed by malignancy, in both the initial aortic valve replacement (AVR) cohort (N = 1197), and the conservative management cohort (N = 2618). Both non-cardiac factors (age, male, body mass index <22, diabetes, prior history of stroke, dialysis, anemia, and malignancy) and cardiac factors (atrial fibrillation, ejection fraction <68%, and the initial AVR strategy) were associated with non-cardiac death. These findings highlight the importance of close monitoring of non-cardiac comorbidities, as well as HF and sudden death, to improve the mortality rate of severe AS patients.


Heart | 2017

Impact of the left ventricular mass index on the outcomes of severe aortic stenosis

Eri Minamino-Muta; Takao Kato; Takeshi Morimoto; Tomohiko Taniguchi; Moriaki Inoko; Tetsuya Haruna; Toshiaki Izumi; Shoichi Miyamoto; Eisaku Nakane; Kenichi Sasaki; Moritoshi Funasako; Koji Ueyama; Shinichi Shirai; Takeshi Kitai; Chisato Izumi; Kazuya Nagao; Tsukasa Inada; Eiji Tada; Akihiro Komasa; Katsuhisa Ishii; Naritatsu Saito; Ryuzo Sakata; Kenji Minatoya; Takeshi Kimura

Objective To elucidate the factors associated with high left ventricular mass index (LVMI) and to test the hypothesis that high LVMI is associated with worse outcome in severe aortic stenosis (AS). Methods We analysed 3282 patients with LVMI data in a retrospective multicentre registry enrolling consecutive patients with severe AS in Japan. The management strategy, conservative or initial aortic valve replacement (AVR), was decided by the attending physician. High LVMI was defined as LVMI >115 g/m2 for males and >95 g/m2 for females. We compared the risk between normal and high LVMI in the primary outcome measures compromising aortic valve-related death and heart failure hospitalisation. Results Age was mean 77 (SD 9.6) years and peak aortic jet velocity (Vmax) was 4.1 (0.9) m/s. The factors associated with high LVMI (n=2374) included female, body mass index ≥22, absence of dyslipidemia, left ventricular ejection fraction <50%, Vmax ≥4 m/s, regurgitant valvular disease, hypertension, anaemia and end-stage renal disease. In the conservative management cohort (normal LVMI: n=691, high LVMI: n=1480), the excess adjusted 5-year risk of high LVMI was significant (HR: 1.53, 95% CI 1.26 to 1.85, p<0.001). In the initial AVR cohort (normal LVMI: n=217, high LVMI: n=894), the risk did not differ significantly between the two groups (HR: 0.96, 95% CI 0.60 to 1.55, p=0.88). There was a significant interaction between the initial treatment strategy and the risk of high LVMI (p=0.016). Conclusions The deleterious impact of high LVMI on outcome was observed in patients managed conservatively, but not observed in patients managed with initial AVR. Trial registration number UMIN000012140; Post-results.


Circulation-cardiovascular Interventions | 2017

High- Versus Low-Gradient Severe Aortic Stenosis: Demographics, Clinical Outcomes, and Effects of the Initial Aortic Valve Replacement Strategy on Long-Term Prognosis

Tomohiko Taniguchi; Takeshi Morimoto; Hiroki Shiomi; Kenji Ando; Norio Kanamori; Koichiro Murata; Takeshi Kitai; Yuichi Kawase; Chisato Izumi; Makoto Miyake; Hirokazu Mitsuoka; Masashi Kato; Yutaka Hirano; Shintaro Matsuda; Tsukasa Inada; Kazuya Nagao; Tomoyuki Murakami; Yasuyo Takeuchi; Keiichiro Yamane; Mamoru Toyofuku; Mitsuru Ishii; Eri Minamino-Muta; Takao Kato; Moriaki Inoko; Tomoyuki Ikeda; Akihiro Komasa; Katsuhisa Ishii; Kozo Hotta; Nobuya Higashitani; Yoshihiro Kato

Background— There is considerable debate on the management of patients with low-gradient severe aortic stenosis (LG-AS), defined as aortic valve area <1 cm2 with peak aortic jet velocity ⩽4.0 m/s, and mean aortic pressure gradient ⩽40 mm Hg. Methods and Results— In the CURRENT AS registry (Contemporary Outcomes After Surgery and Medical Treatment in Patients With Severe Aortic Stenosis), there were 2097 patients (initial aortic valve replacement [AVR] strategy: n=977, and conservative strategy: n=1120) with high-gradient severe aortic stenosis (HG-AS) and 1712 patients (initial AVR strategy: n=219, and conservative strategy: n=1493) with LG-AS. AVR was more frequently performed in HG-AS patients than in LG-AS patients (60% versus 28%) during the entire follow-up. In the comparison between the initial AVR and conservative groups, the propensity score–matched cohorts were developed in both HG-AS (n=887 for each group) and LG-AS (n=218 for each group) strata. The initial AVR strategy when compared with the conservative strategy was associated with markedly lower risk for a composite of aortic valve–related death or heart failure hospitalization in both HG-AS and LG-AS strata (hazard ratio, 0.30; 95% confidence interval, 0.25–0.37; P<0.001 and hazard ratio, 0.46; 95% confidence interval, 0.32–0.67; P<0.001, respectively). Among 1358 patients with LG-AS with preserved left ventricular ejection fraction, the initial AVR strategy was associated with a better outcome than the conservative strategy (adjusted hazard ratio, 0.37; 95% confidence interval, 0.23–0.59; P<0.001). Conclusions— The initial AVR strategy was associated with better outcomes than the conservative strategy in both HG-AS and LG-AS patients, although AVR was less frequently performed in LG-AS patients than in HG-AS patients. The favorable effect of initial AVR strategy was also seen in patients with LG-AS with preserved left ventricular ejection fraction. Clinical Trial Registration— URL: http://www.umin.ac.jp/ctr/index.htm. Unique identifier: UMIN000012140.


Circulation | 2017

Sex Differences in Severe Aortic Stenosis ― Clinical Presentation and Mortality ―

Mamoru Toyofuku; Tomohiko Taniguchi; Takeshi Morimoto; Kyohei Yamaji; Yutaka Furukawa; Kosuke Takahashi; Takashi Tamura; Hiroki Shiomi; Kenji Ando; Norio Kanamori; Koichiro Murata; Takeshi Kitai; Yuichi Kawase; Chisato Izumi; Makoto Miyake; Hirokazu Mitsuoka; Masashi Kato; Yutaka Hirano; Shintaro Matsuda; Tsukasa Inada; Tomoyuki Murakami; Yasuyo Takeuchi; Keiichiro Yamane; Mitsuru Ishii; Eri Minamino-Muta; Takao Kato; Moriaki Inoko; Tomoyuki Ikeda; Akihiro Komasa; Katsuhisa Ishii

BACKGROUND There is a paucity of data on the sex differences in the prevalence, clinical presentation, and prognosis of aortic stenosis (AS).Methods and Results:A total of 3,815 consecutive patients with severe AS were enrolled in the multicenter CURRENT AS registry between January 2003 and December 2011. The registry included 1,443 men (38%) and 2,372 women (62%). Women were much older than men (79±10 vs. 75±10 years, P<0.0001), and the ratio of women to men increased with age. The cumulative 5-year incidence of all-cause death was significantly higher in men than in women (47% vs. 41%, P=0.003), although women were more symptomatic and much older. The 5-year mortality was similar between men and women at age <65 years (16% vs. 15%, P=0.99), whereas it was significantly higher in men than in women at age ≥65 years (65-74 years, 38% vs. 19%, P<0.0001; 75-84 years, 55% vs. 34%, P<0.0001; ≥85 years: 82% vs. 72%, P=0.03). CONCLUSIONS A large Japanese multicenter registry of consecutive patients with severe AS included a much higher proportion of women than men, with the female:male sex ratio increasing with age. The 5-year mortality rate of women was lower than that of men. Lower 5-year mortality rates in women were consistently seen across all age groups >65 years.


Circulation | 2017

Acute Heart Failure in Patients With Severe Aortic Stenosis ― Insights From the CURRENT AS Registry ―

Kazuya Nagao; Tomohiko Taniguchi; Takeshi Morimoto; Hiroki Shiomi; Kenji Ando; Norio Kanamori; Koichiro Murata; Takeshi Kitai; Yuichi Kawase; Chisato Izumi; Makoto Miyake; Hirokazu Mitsuoka; Masashi Kato; Yutaka Hirano; Shintaro Matsuda; Tsukasa Inada; Tomoyuki Murakami; Yasuyo Takeuchi; Keiichiro Yamane; Mamoru Toyofuku; Mitsuru Ishii; Eri Minamino-Muta; Takao Kato; Moriaki Inoko; Tomoyuki Ikeda; Akihiro Komasa; Katsuhisa Ishii; Kozo Hotta; Nobuya Higashitani; Yoshihiro Kato

BACKGROUND Clinical profiles of acute heart failure (AHF) complicating severe aortic stenosis (AS) remain unclear.Methods and Results:From a Japanese multicenter registry enrolling consecutive patients with severe AS, 3,813 patients were categorized into the 3 groups according to the symptom of heart failure (HF); No HF (n=2,210), chronic HF (CHF) (n=813) and AHF defined as hospitalized HF at enrolment (n=790). Median follow-up was 1,123 days with 93% follow-up rate at 2 years. Risk factors for developing AHF included age, female sex, lower body mass index, untreated coronary artery stenosis, anemia, history of HF, left ventricular ejection fraction <50%, presence of any combined valvular disease, peak aortic jet velocity ≥5 m/s and tricuspid regurgitation pressure gradient ≥40 mmHg, and negative risk factors included dyslipidemia, history of percutaneous coronary intervention and hemodialysis. Respective cumulative 5-year incidences of all-cause death and HF hospitalization in No HF, CHF and AHF groups were 37.1%, 41.8% and 61.8% (P<0.001) and 20.7%, 33.8% and 52.3% (P<0.001). Even in the initial aortic valve replacement (AVR) stratum, AHF was associated with excess 5-year mortality risk relative to No HF and CHF (adjusted hazard ratio [HR] 1.64; 95% confidence interval [CI]: 1.14-2.36, P=0.008; adjusted HR 1.47; 95% CI: 1.03-2.11, P=0.03, respectively). CONCLUSIONS AHF complicating severe AS was associated with an extremely dismal prognosis, which could not be fully resolved by AVR. Careful management to avoid the development of AHF is crucial.


Esc Heart Failure | 2017

Kyoto Congestive Heart Failure (KCHF) Study: Rationale and Design.

Erika Yamamoto; Takao Kato; Neiko Ozasa; Hidenori Yaku; Yasutaka Inuzuka; Yodo Tamaki; Takeshi Kitai; Takeshi Morimoto; Ryoji Taniguchi; Moritake Iguchi; Masashi Kato; Mamoru Takahashi; Toshikazu Jinnai; Tomoyuki Ikeda; Kazuya Nagao; Takafumi Kawai; Akihiro Komasa; Ryusuke Nishikawa; Yuichi Kawase; Takashi Morinaga; Tsuneaki Kawashima; Yasuyo Motohashi; Mitsunori Kawato; Mamoru Toyofuku; Yukihito Sato; Koichiro Kuwahara; Tetsuo Shioi; Takeshi Kimura

Over the last decade, major developments in medicine have led to significant changes in the clinical management of heart failure patients. This study was designed to evaluate the recent trends in clinical characteristics, management, and short‐term and long‐term prognosis of patients with acute decompensated heart failure (ADHF) in Japan.


Scientific Reports | 2018

Asymptomatic versus Symptomatic Patients with Severe Aortic Stenosis

Norio Kanamori; Tomohiko Taniguchi; Takeshi Morimoto; Hiroki Shiomi; Kenji Ando; Koichiro Murata; Takeshi Kitai; Yuichi Kawase; Chisato Izumi; Makoto Miyake; Hirokazu Mitsuoka; Masashi Kato; Yutaka Hirano; Shintaro Matsuda; Kazuya Nagao; Tsukasa Inada; Hiroshi Mabuchi; Yasuyo Takeuchi; Keiichiro Yamane; Mamoru Toyofuku; Mitsuru Ishii; Eri Minamino-Muta; Takao Kato; Moriaki Inoko; Tomoyuki Ikeda; Akihiro Komasa; Katsuhisa Ishii; Kozo Hotta; Nobuya Higashitani; Yoshihiro Kato

It is unknown how much different are the clinical outcomes between asymptomatic and symptomatic patients with severe aortic stenosis (AS). In the CURRENT AS registry enrolling 3,815 consecutive patients with severe AS, we compared the long-term outcomes between 1808 asymptomatic and 1215 symptomatic patients (exertional dyspnea: N = 813, syncope: N = 136, and angina: N = 266) without heart failure (HF) hospitalization. Symptomatic patients had greater AS severity, and more depressed left ventricular function than asymptomatic patients without much difference in other baseline characteristics. During a median follow-up of 3.2 years, aortic valve replacement (AVR) was performed in 62% of symptomatic patients, and 38% of asymptomatic patients. The cumulative 5-year incidences for the primary outcome measure (a composite of aortic valve-related death or HF hospitalization) was higher in symptomatic patients than in asymptomatic patients (32.3% versus 27.6%, P < 0.001). After adjusting for AVR and other variables, the greater risk of symptomatic relative to asymptomatic patients for the primary outcome measure was significant (hazard ratio 1.64, 95% confidence interval 1.41–1.96, P < 0.001). In conclusions, the excess risk of symptomatic relative to asymptomatic patients with severe AS for the aortic valve-related event was significant. However, the prevalence of AVR in symptomatic patients was not optimal.


European Heart Journal - Quality of Care and Clinical Outcomes | 2018

Malignant disease as a comorbidity in patients with severe aortic stenosis: clinical presentation, outcomes, and management

Eri Minamino-Muta; Takao Kato; Takeshi Morimoto; Tomohiko Taniguchi; Kenji Nakatsuma; Yuki Kimura; Moriaki Inoko; Shinichi Shirai; Norio Kanamori; Koichiro Murata; Takeshi Kitai; Yuichi Kawase; Makoto Miyake; Chisato Izumi; Hirokazu Mitsuoka; Yutaka Hirano; Tomoki Sasa; Kazuya Nagao; Tsukasa Inada; Ryusuke Nishikawa; Yasuyo Takeuchi; Shintaro Yamagami; Keiichiro Yamane; Kanae Su; Akihiro Komasa; Katsuhisa Ishii; Yugo Yamashita; Yoshihiro Kato; Kensuke Takabayashi; Naritatsu Saito

Aim To investigate the effect of malignancy on the outcomes of patients with severe aortic stenosis (AS) and the management strategy for AS with malignancy. Methods and results Using data of 3815 patients with severe AS in a retrospective multicentre registry [CURRENT AS (Contemporary outcomes after sURgery and medical tREatmeNT in patients with severe Aortic Stenosis) registry], we compared 3-year clinical outcomes among three groups based on malignancy status: with malignancy currently under treatment including best supportive care (malignancy group), with a history of malignancy without any current treatment (past history group), or without history of malignancy (no malignancy group). Patients in the malignancy group (n = 124) were more often men and had higher prevalence of low body mass index, recurrence of malignancy, anaemia, and asymptomatic status, despite comparable surgical risks and echocardiographic parameters. The malignancy group or the past history group (n = 389) had significantly higher risk for all-cause death [hazard ratio (HR) 2.49, 95% CI (95% confidence interval) 1.98-3.14; HR 1.23, 95% CI 1.04-1.46] and for malignancy-related death (HR 16.2, 95% CI 10.64-24.54; HR 3.66, 95% CI 2.43-5.52) than that of the no malignancy group (n = 3302). The excess risk for aortic valve-related death was not observed in the malignancy group (HR 0.79, 95% CI 0.48-1.29) and was lower in the past history group (HR 0.72, 95% CI 0.53-0.96). In the malignancy group, the treatment strategy (surgery: n = 16, conservative management: n = 108) was determined based on the clinical status of AS or life expectancy. Conclusions Malignancy had marked effect on all-cause death and malignancy-related death in patients with severe AS. History of malignancy also had a smaller but significant effect on mortality.


Circulation | 2018

Demographics, Management, and In-Hospital Outcome of Hospitalized Acute Heart Failure Syndrome Patients in Contemporary Real Clinical Practice in Japan ― Observations From the Prospective, Multicenter Kyoto Congestive Heart Failure (KCHF) Registry ―

Hidenori Yaku; Neiko Ozasa; Takeshi Morimoto; Yasutaka Inuzuka; Yodo Tamaki; Erika Yamamoto; Yusuke Yoshikawa; Takeshi Kitai; Ryoji Taniguchi; Moritake Iguchi; Masashi Kato; Mamoru Takahashi; Toshikazu Jinnai; Tomoyuki Ikeda; Kazuya Nagao; Takafumi Kawai; Akihiro Komasa; Ryusuke Nishikawa; Yuichi Kawase; Takashi Morinaga; Kanae Su; Mitsunori Kawato; Kenichi Sasaki; Mamoru Toyofuku; Yutaka Furukawa; Yoshihisa Nakagawa; Kenji Ando; Kazushige Kadota; Satoshi Shizuta; Koh Ono

BACKGROUND There is a scarcity of reports on the clinical characteristics and management practice in contemporary all-comer patients with acute decompensated heart failure (ADHF). Methods and Results: The Kyoto Congestive Heart Failure (KCHF) registry is a prospective observational cohort study enrolling 4,056 consecutive patients who had hospital admission due to ADHF without any exclusion criteria between October 2014 and March 2016 in the 19 participating hospitals in Japan. Baseline characteristics, clinical presentations, management, and in-hospital outcomes were compared between heart failure (HF) with reduced left ventricular ejection fraction (LVEF; HFrEF, LVEF <40%), HF with mid-range LVEF (HFmrEF, LVEF 40-49%), and HF with preserved LVEF (HFpEF, LVEF ≥50%). Of the 4,041 patients with documented LVEF, 1,744 (43%) had HFpEF; 746 (19%), HFmrEF; and 1,551 (38%), HFrEF. The median age was 80 years (IQR, 72-86 years) in the entire population, and was higher with increasing LVEF (P<0.001). The in-hospital mortality rate was higher in the HFrEF than in the HFmrEF and HFpEF groups (9.2%, 4.8%, and 5.1%, respectively, P<0.001). CONCLUSIONS This registry elucidated the clinical features and clinically relevant in-hospital outcomes in contemporary consecutive patients with ADHF in real-world clinical practice in Japan. When classified by LVEF, significant differences in characteristics and in-hospital outcomes existed between patients with HFrEF, HFmrEF, and HFpEF.

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