Ryo Nakamaru

Dr. Ryo Nakamaru

orcid

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

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

Representative Publications

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3 January 2025 in Circulation Research
Verified
Journal Article
Open access
SYShota Yoshida
Shota Yoshida
HHHiroki Hayashi
Hiroki Hayashi
TKTakuro Kawahara
Takuro Kawahara
SKShunsuke Katsuki
Shunsuke Katsuki
MKMitsukuni Kimura
Mitsukuni Kimura
HNHironori Nakagami
Hironori Nakagami
BACKGROUND: Myofibroblasts are primary cells involved in chronic response-induced cardiac fibrosis. Fibroblast activation protein (FAP) is a relatively specific marker of activated myofibroblasts and a potential target molecule. This study aimed to clarify whether a vaccine targeting FAP could eliminate myofibroblasts in chronic cardiac stress model mice and reduce cardiac fibrosis. METHODS: We coadministered a FAP peptide vaccine with a cytosine-phosphate-guanine (CpG) K3 oligonucleotide adjuvant to male C57/BL6J mice and confirmed an elevation in the anti-FAP antibody titer. After continuous angiotensin II and phenylephrine administration for 28 days, we evaluated the degree of cardiac fibrosis and the number of myofibroblasts in cardiac tissues. RESULTS: We found that cardiac fibrosis was significantly decreased in the FAP-vaccinated mice compared with the angiotensin II and phenylephrine control mice (3.45±1.11% versus 8.62±4.79%; P =4.59×10 −3 ) and that the accumulation of FAP-positive cells was also significantly decreased, as indicated by FAP immunohistochemical staining (4077±1746 versus 7327±1741 cells/mm 2 ; FAP vaccine versus angiotensin II and phenylephrine control; P =6.67×10 −3 ). No systemic or organ-specific inflammation due to antibody-dependent cell cytotoxicity induced by the FAP vaccine was observed. Although the transient activation of myofibroblasts has an important role in maintaining the structural robustness in the process of tissue repair, the FAP vaccine showed no adverse effects in myocardial infarction and skin injury models. CONCLUSIONS: Our study demonstrates the FAP vaccine can be a therapeutic tool for cardiac fibrosis.

27 November 2022 in ESC Heart Failure
Verified
Journal Article
Open access
RNRyo Nakamaru
Ryo Nakamaru
YSYasuyuki Shiraishi
Yasuyuki Shiraishi
ASAlexander T. Sandhu
Alexander T. Sandhu
PHPaul Heidenreich
Paul Heidenreich
SSSatoshi Shoji
Satoshi Shoji
TYTsutomu Yoshikawa
Tsutomu Yoshikawa
Aims: The long-term outcome in patients with heart failure (HF) after hospitalization may vary substantially depending on their age and left ventricular ejection fraction (LVEF). We aimed to assess the relative rates of cardiovascular death (CVD) and non-CVD based on the age and how the rates differ under the updated LVEF classification system. Methods and results: Consecutively registered hospitalized patients with HF (N = 3558; 39.7% women with a mean age of 73.9 ± 13.3 years) were followed for a median of 2 (interquartile range, 0.8–3.1) years. The CVDs and non-CVDs were evaluated based on age [young (<65 years), older (65–84 years), and very old (≥85 years)] and LVEF classification [HF with preserved EF (HFpEF; LVEF ≥50%) and non-HFpEF (LVEF <50%)]. The adverse clinical events were adjudicated independently by a central committee. Overall, 1505 (42.3%) had HFpEF [young: n = 182 (12.1%), older: n = 894 (59.4%), very old: n = 429 (28.5%)], and 2053 (57.7%) had non-HFpEF [young: n = 575 (28.0%), older: n = 1159 (56.5%), very old: n = 319 (15.5%)]. During the follow-up, the crude incidence of all-cause death was higher in non-HFpEF than in HFpEF across all age groups (non-HFpEF vs. HFpEF, young: 10.4% vs. 5.5%, log-rank P = 0.10; older: 26.6% vs. 20.9%, log-rank P = 0.002; very old: 36.7% vs. 31.7%, log-rank P = 0.043). CVDs accounted for more than half of all deaths in non-HFpEF (young 65.0%, older 64.2%, and very old 55.6%), whereas the proportion of CVDs remained less than half in HFpEF (young 50.0%, older 41.2%, very old 38.2%). HF readmission was associated with subsequent all-cause death in non-HFpEF [hazard ratio (HR): 1.72, 95% confidence interval (CI): 1.41–2.09, P < 0.001], but not in HFpEF (HR: 1.12, 95% CI: 0.87–1.43, P = 0.39). Conclusions: The probability of a non-CVD increases in both LVEF categories with advancing age, but that it is greater in the HFpEF category. The findings indicate that mitigating CV-related outcomes alone may be insufficient for treating HF in older population, particularly in the HFpEF category.

7 November 2023 in Journal of the American Heart Association
Verified
Journal Article
Open access
RNRyo Nakamaru
Ryo Nakamaru
SKShun Kohsaka
Shun Kohsaka
YSYasuyuki Shiraishi
Yasuyuki Shiraishi
TKTakashi Kohno
Takashi Kohno
AGAyumi Goda
Ayumi Goda
TYTsutomu Yoshikawa
Tsutomu Yoshikawa
Background: The management of heart failure (HF) has markedly changed, due to changes in demographics and the emergence of novel pharmacotherapies. However, detailed analyses on the temporal trends in characteristics and outcomes among patients with HF are scarcely available. This study aimed to assess the temporal trends over 11 years in clinical management and outcomes in patients with HF. Methods and Results: We analyzed data from a multicenter registry of hospitalized patients with acute HF, including 6877 patients registered from 2011 to 2021. Age‐adjusted mortality was calculated using standardized mortality ratios. During the study period, mean age increased from 75.2 years in 2011 to 2012 to 76.4 years in 2020 to 2021 ( P for trend <0.001). The proportion of HF with reduced ejection fraction (HFrEF, left ventricular ejection fraction <40%) remained constant (from 43.4% to 42.7%, P for trend=0.38). The median duration of hospital stays (from 15 to 17 days, P for trend<0.001) had increased. As for the implementation of guideline‐directed medical therapy, the use of mineralocorticoid receptor antagonist at discharge increased in patients with HFrEF (from 44.3% to 60.2%, P for trend<0.001). There was also an increase in the use of sodium‐glucose cotransporter‐2 inhibitors following their approval for use. The age‐adjusted 1‐year mortality decreased in patients with HFrEF (from 18.0% to 9.3%, P for trend<0.001) but not in patients with non‐HFrEF (left ventricular ejection fraction ≥40%; from 9.2% to 9.5%, P for trend=0.79). Conclusions: Hospitalized patients with HF have been aging over the past decade. Their long‐term outcomes after discharge have improved predominantly because of decreased mortality in patients with HFrEF.

7 February 2023 in Journal of the American Heart Association
Verified
Journal Article
Closed access
RNRyo Nakamaru
Ryo Nakamaru
YSYasuyuki Shiraishi
Yasuyuki Shiraishi
NNNozomi Niimi
Nozomi Niimi
TKTakashi Kohno
Takashi Kohno
Yuji NagatomoYuji Nagatomo
Yuji Nagatomo
TYTsutomu Yoshikawa
Tsutomu Yoshikawa
Background: The burden of noncardiovascular conditions is becoming increasingly prevalent in patients with heart failure (HF). We aimed to identify novel phenogroups incorporating noncardiovascular conditions to facilitate understanding and risk stratification in elderly patients with HF. Methods and Results: Data from a total of 1881 (61.2%) patients aged ≥65 years were extracted from a prospective multicenter registry of patients hospitalized for acute HF (N=3072). We constructed subgroups of patients with HF with preserved ejection fraction (HFpEF; N=826, 43.9%) and those with non‐HFpEF (N=1055, 56.1%). Latent class analysis was performed in each subgroup using 17 variables focused on noncardiovascular conditions (including comorbidities, Clinical Frailty Scale, and Geriatric Nutritional Risk Index). The latent class analysis revealed 3 distinct clinical phenogroups in both HFpEF and non‐HFpEF subgroups: (1) robust physical and nutritional status (Group 1: HFpEF, 41.2%; non‐HFpEF, 46.0%); (2) multimorbid patients with renal impairment (Group 2: HFpEF, 40.8%; non‐HFpEF, 41.9%); and (3) malnourished patients (Group 3: HFpEF, 18.0%; non‐HFpEF, 12.1%). After multivariable adjustment, compared with Group 1, patients in Groups 2 and 3 had a higher risk for all‐cause death over the 1‐year postdischarge period (hazard ratio [HR], 2.79 [95% CI, 1.64–4.81] and HR, 2.73 [95% CI, 1.39–5.35] in HFpEF; HR, 1.96 [95% CI, 1.22–3.14] and HR, 2.97 [95% CI, 1.64–5.38] in non‐HFpEF; respectively). Conclusions: In elderly patients with HF, the phenomapping focused on incorporating noncardiovascular conditions identified 3 phenogroups, each representing distinct clinical outcomes, and the discrimination pattern was similar for both patients with HFpEF and non‐HFpEF. This classification provides novel risk stratification and may aid in clinical decision making.

1 August 2024 in Circulation: Cardiovascular Quality and Outcomes
Verified
Journal Article
Closed access
RNRyo Nakamaru
Ryo Nakamaru
SNShiori Nishimura
Shiori Nishimura
HKHiraku Kumamaru
Hiraku Kumamaru
SSSatoshi Shoji
Satoshi Shoji
ENEiji Nakatani
Eiji Nakatani
SKShun Kohsaka
Shun Kohsaka
BACKGROUND: The increasing prevalence of frailty has gained considerable attention due to its profound influence on clinical outcomes. However, our understanding of the progression of frailty and long-term clinical outcomes in older individuals with atrial fibrillation remains scarce. METHODS: Using data from 2012 to 2018 from a comprehensive claims database incorporating primary and hospital care records in Shizuoka, Japan, we selected patients aged ≥65 years with atrial fibrillation who initiated oral anticoagulant therapy. The trajectory of frailty was plotted using Sankey plots, illustrating the annual changes in their frailty according to the electronic frailty index during a 3-year follow-up after oral anticoagulant initiation, along with the incidence of clinical adverse outcomes. For deceased patients, we assessed their frailty status in the year preceding their death. RESULTS: Of 6247 eligible patients (45.1% women; mean age, 79.3±8.0 years) at oral anticoagulant initiation, 7.7% were categorized as fit (electronic frailty index, 0–0.12), 30.1% as mildly frail (>0.12–0.24), 35.4% as moderately frail (>0.24–0.36), and 25.9% as severely frail (>0.36). Over the 3-year follow-up, 10.4% of initially fit patients transitioned to moderately frail or severely frail. Conversely, 12.5% of severely frail patients improved to fit or mildly frail. Death, stroke, and major bleeding occurred in 23.4%, 4.1%, and 2.2% of patients, respectively. Among the mortality cases, 74.8% (N=1183) and 3.5% (N=55) had experienced moderately or severely frail and either a stroke or major bleeding in the year preceding their death, respectively. CONCLUSIONS: In a contemporary era of atrial fibrillation management, a minor fraction of older patients on oral anticoagulants died following a stroke or major bleeding. However, their frailty demonstrated a dynamic trajectory, and a substantial proportion of death was observed after transitioning to a moderately or severely frail state.

30 August 2022 in Vaccines
Verified
Journal Article
Open access
PDF file
HNHironori Nakagami
Hironori Nakagami
HHHiroki Hayashi
Hiroki Hayashi
JSJiao Sun
Jiao Sun
YYYuka Yanagida
Yuka Yanagida
TOTakako Otera
Takako Otera
HRHiromi Rakugi
Hiromi Rakugi
We conducted a nonrandomized, open-label phase I study to assess the safety and immunogenicity of an intradermal coronavirus disease 2019 (COVID-19) DNA vaccine (AG0302-COVID-19) administered using a pyro-drive jet injector at Osaka University Hospital between Yanagida November 2020 and December 2021. Twenty healthy volunteers, male or female, were enrolled in the low-dose (0.2 mg) or high-dose (0.4 mg) groups and administered AG0302-COVID19 twice at a 2-week interval. There were no adverse events that led to discontinuation of the study drug vaccination schedule. A serious adverse event (disc protrusion) was reported in one patient in the high-dose group, but the individual recovered, and the adverse event was not causally related to the study drug. In the analysis of the humoral immune response, the geometric mean titer (GMT) of serum anti-SARS-CoV-2 spike glycoprotein-specific antibody was low in both the low-dose and high-dose groups (246.2 (95% CI 176.2 to 344.1, 348.2 (95% CI 181.3 to 668.9)) at the 8 weeks after first vaccination. Regarding the analysis of the cellular immune, the number of IFN-γ-producing cells responsive to the SARS-CoV-2 spike glycoprotein increased with individual differences after the first dose and was sustained for several months. Overall, no notable safety issues were observed with the intradermal inoculations of AG0302-COVID19. Regarding immunogenicity, a cellular immune response was observed in some subjects after AG0302-COVID19 intradermal inoculation, but no significant antibody production was observed.