Masafumi Shibata, MD, PhD

All Publications

• The Circulatory Arrest Recovery Ammonia Problem (CARAP) Hypothesis: a 1H-MRS study of brain metabolism during neonatal cardiopulmonary bypass surgery. The Journal of thoracic and cardiovascular surgery Spielman, D., Gu, M., Liu, H., Liu, S. C., Hurd, R., Riemer, K., Okamura, K., Shibata, M., Shuttleworth, P., Kleiman, Z., Epperson, K., Epperson, K., Hanley, F. 2025

  Abstract

  Congenital heart disease affects 1% of US births, with many babies requiring major cardiothoracic surgery under cardiopulmonary bypass (CPB), exposing the more critical patients to neurodevelopmental impairment. Optimal surgical parameters to minimize neuronal injury are unknown. We used 1H MRS and blood ammonia assays in a neonatal pig model of CPB to compare two approaches, complete circulatory arrest (CA) versus antegrade cerebral perfusion (ACP).Two-week old piglets (N=17) were put on a CPB pump and placed in a 3T MRI to study brain metabolism during CPB. Dynamic single-voxel 1H MRS brain data were acquired while animals underwent one of four CPB protocols: ∼50 min CA at 18ºC and 28ºC or ACP at 18ºC and 28ºC, followed by a ∼1-hr recovery period. Based on 1H MRS findings suggesting the presence of brain ammonia upon reperfusion, a second cohort of piglets (N=22) underwent the same CPB conditions without MRS to allow regular venous blood sampling with ammonia assays.All animals showed a transitory temperature-dependent rise in blood ammonia (p < .001) immediately following restart of whole-body perfusion . In contrast, metabolic processing of brain ammonia, as detected by an increased 1H MRS glutamine/glutamate ratio, was also temperature dependent (p =.002) but only significantly observed in the CA studies (p =.009).Serial 1H-MRS and blood ammonia assays in this preclinical CPB model identified a previously unreported build-up of ammonia, hypothesized to arise from gut bacterial production, following reperfusion, that may contribute to brain injury in these pediatric surgeries.

  View details for DOI 10.1016/j.jtcvs.2025.01.016

  View details for PubMedID 39855339

• A Low-Cost, Open-Source 3D Printer for Multimaterial and High-Throughput Direct Ink Writing of Soft and Living Materials. Advanced materials (Deerfield Beach, Fla.) Weiss, J. D., Mermin-Bunnell, A., Solberg, F. S., Tam, T., Rosalia, L., Sharir, A., Rütsche, D., Sinha, S., Choi, P. S., Shibata, M., Palagani, Y., Nilkant, R., Paulvannan, K., Ma, M., Skylar-Scott, M. A. 2025: e2414971

  Abstract

  Direct ink writing is a 3D printing method that is compatible with a wide range of structural, elastomeric, electronic, and living materials, and it continues to expand its uses into physics, engineering, and biology laboratories. However, the large footprint, closed hardware and software ecosystems, and expense of commercial systems often hamper widespread adoption. This work introduces a compact, low-cost, multimaterial, and high-throughput direct ink writing 3D printer platform with detailed assembly files and instructions provided freely online. In contrast to existing low-cost 3D printers and bioprinters, which typically modify off-the-shelf plastic 3D printers, this system is built from scratch, offering a lower cost and full customizability. Active mixing of cell-laden bioinks, high-throughput production of auxetic lattices using multimaterial multinozzle 3D (MM3D) printing methods, and a high-toughness, photocurable hydrogel for fabrication of heart valves are introduced. Finally, hardware for embedded multinozzle and 3D gradient nozzle printing is developed for producing high-throughput and graded 3D parts. This powerful, simple-to-build, and customizable printing platform can help stimulate a vibrant biomaker community of engineers, biologists, and educators.

  View details for DOI 10.1002/adma.202414971

  View details for PubMedID 39748617

• Simplified prediction of the right-left cusp overlap view for transcatheter aortic valve replacement: The rule of 22 JTCVS Structural and Endovascular Shibata, M., Abdelhafez, A., Fitzgerald, S., Trejo-Velasco, B., Kitamura, M., Jobs, A., Wilde, J., Desch, S., Thiele, H., Abdel-Wahab, M. 2025; 5

  View details for DOI 10.1016/j.xjse.2024.100036

• Detection of elevated succinate in brain during circulatory arrest in a piglet model: A 3T 1H MR spectroscopy study. Magnetic resonance in medicine Hurd, R. E., Gu, M., Okamura, K., Shibata, M., Ono, Y., Haidar, M., Riemer, R. K., Hanley, F. L., Spielman, D. M. 2024

  Abstract

  To measure and validate elevated succinate in brain during circulatory arrest in a piglet model of cardiopulmonary bypass.Using data from an archive of 3T 1H MR spectra acquired in previous in-magnet studies, dynamic plots of succinate, spectral simulations and difference spectra were generated for analysis and validation.Elevation of succinate during circulatory arrest was observed and validated. Fitting bias was evaluated as a function of the line-widths and signal-to-noise ratios of the archived data. Succinate increases were independent of bypass temperature. Succinate elevation was also not observed with antegrade cerebral perfusion.Although spectrally overlapped and at sub-millimolar levels, elevated brain succinate can be reliably measured by dynamic MR spectroscopy at 3T. Noise dependent bias of the stronger overlapping signals did not impact the succinate measurement. Elevated succinate during circulatory arrest and its recovery after reperfusion was observed. This finding is consistent with earlier reports that correlate elevated succinate with ischemic-reperfusion injury.

  View details for DOI 10.1002/mrm.30414

  View details for PubMedID 39737693

• Combined simulation and ex vivo assessment of free-edge length in bicuspidization repair for congenital aortic valve disease. JTCVS open Choi, P. S., Sharir, A., Ono, Y., Shibata, M., Kaiser, A. D., Palagani, Y., Marsden, A. L., Ma, M. R. 2024; 22: 395-404

  Abstract

  The study objective was to investigate the effect of free-edge length on valve performance in bicuspidization repair of congenitally diseased aortic valves.In addition to a constructed unicuspid aortic valve disease model, 3 representative groups-free-edge length to aortic diameter ratio 1.2, 1.57, and 1.8-were replicated in explanted porcine aortic roots (n = 3) by adjusting native free-edge length with bovine pericardium. Each group was run on a validated ex vivo univentricular system under physiological parameters for 20 cycles. All groups were tested within the same aortic root to minimize inter-root differences. Outcomes included transvalvular gradient, regurgitation fraction, and orifice area. Linear mixed effects model and pairwise comparisons were used to compare outcomes across groups.The diseased control group had a mean transvalvular gradient of 28.3 ± 5.5 mm Hg, regurgitation fraction of 29.6% ± 8.0%, and orifice area of 1.03 ± 0.15 cm2. In ex vivo analysis, all repair groups had improved regurgitation and transvalvular gradient compared with the diseased control group (P < .001). Free-edge length to aortic diameter of 1.8 had the highest amount of regurgitation among the repair groups (P < .001) and 1.57 the least (P < .001). Free-edge length to aortic diameter of 1.57 also exhibited the lowest mean gradient (P < .001) and the largest orifice area (P < .001).Free-edge length to aortic diameter ratio significantly impacts valve function in bicuspidization repair of congenitally diseased aortic valves. As the ratio departs from 1.57 in either direction, effective orifice area decreases and both transvalvular gradient and regurgitation fraction increase.

  View details for DOI 10.1016/j.xjon.2024.09.008

  View details for PubMedID 39780804

  View details for PubMedCentralID PMC11704580

• Harnessing the Power of ChatGPT in Cardiovascular Medicine: Innovations, Challenges, and Future Directions. Journal of clinical medicine Leon, M., Ruaengsri, C., Pelletier, G., Bethencourt, D., Shibata, M., Flores, M. Q., Shudo, Y. 2024; 13 (21)

  Abstract

  Cardiovascular diseases remain the leading cause of morbidity and mortality globally, posing significant challenges to public health. The rapid evolution of artificial intelligence (AI), particularly with large language models such as ChatGPT, has introduced transformative possibilities in cardiovascular medicine. This review examines ChatGPT's broad applications in enhancing clinical decision-making-covering symptom analysis, risk assessment, and differential diagnosis; advancing medical education for both healthcare professionals and patients; and supporting research and academic communication. Key challenges associated with ChatGPT, including potential inaccuracies, ethical considerations, data privacy concerns, and inherent biases, are discussed. Future directions emphasize improving training data quality, developing specialized models, refining AI technology, and establishing regulatory frameworks to enhance ChatGPT's clinical utility and mitigate associated risks. As cardiovascular medicine embraces AI, ChatGPT stands out as a powerful tool with substantial potential to improve therapeutic outcomes, elevate care quality, and advance research innovation. Fully understanding and harnessing this potential is essential for the future of cardiovascular health.

  View details for DOI 10.3390/jcm13216543

  View details for PubMedID 39518681

• Effect of graft sizing in valve-sparing aortic root replacement for bicuspid aortic valve: The Goldilocks ratio. JTCVS techniques Choi, P. S., Sharir, A., Ono, Y., Shibata, M., Kaiser, A. D., Zhu, Y., Marsden, A. L., Woo, Y. J., Ma, M. R., Kim, J. B. 2024; 25: 1-7

  Abstract

  To investigate the effect of graft sizing on valve performance in valve-sparing aortic root replacement for bicuspid aortic valve.In addition to a diseased control model, 3 representative groups-free-edge length to aortic/graft diameter (FELAD) ratio <1.3, 1.5 to 1.64, and >1.7-were replicated in explanted porcine aortic roots (n = 3) using straight grafts sized respective to the native free-edge length. They were run on a validated ex vivo univentricular system under physiological parameters for 20 cycles. All groups were tested within the same aortic root to minimize inter-root differences. Outcomes included transvalvular gradient, regurgitation fraction, and orifice area. Linear mixed effects model and pairwise comparisons were employed to compare outcomes across groups.The diseased control had mean transvalvular gradient 10.9 ± 6.30 mm Hg, regurgitation fraction 32.5 ± 4.91%, and orifice area 1.52 ± 0.12 cm2. In ex vivo analysis, all repair groups had improved regurgitation compared with control (P < .001). FELAD <1.3 had the greatest amount of regurgitation among the repair groups (P < .001) and 1.5-1.64 the least (P < .001). FELAD <1.3 and >1.7 exhibited greater mean gradient compared with both control and 1.5 to 1.64 (P < .001). Among the repair groups, 1.5 to 1.64 had the largest orifice area, and >1.7 the smallest (P < .001).For a symmetric bicuspid aortic valve, performance after valve-sparing aortic root replacement shows a bimodal distribution across graft size. As the FELAD ratio departs from 1.5 to 1.64 in either direction, significant increases in transvalvular gradient are observed. FELAD <1.3 may also result in suboptimal improvement of baseline regurgitation.

  View details for DOI 10.1016/j.xjtc.2024.03.025

  View details for PubMedID 38899072

  View details for PubMedCentralID PMC11184666

• Femoral Arterial Calcification and Plug- vs. Suture-Based Closure Device Strategies Post-Transcatheter Aortic Valve Implantation: Insights From CHOICE-CLOSURE. Structural heart : the journal of the Heart Team Fitzgerald, S., Dumpies, O., Shibata, M., Hartung, P., Obradovic, D., Boekstegers, P., Vorpahl, M., Rotta Detto Loria, J., Kiefer, P., Desch, S., Thiele, H., Abdel-Wahab, M. 2024; 8 (2): 100236

  Abstract

  The location and severity of vascular calcification may influence closure device success in transfemoral transcatheter aortic valve implantation. The aim of this study was to analyze effects of vascular access-site calcification on vascular and bleeding outcomes post-transcatheter aortic valve implantation.The Randomized Comparison of CatHeter-based Strategies fOr Interventional ACcess SitE CLOSURE during Transfemoral Transcatheter Aortic Valve Implantation (CHOICE-CLOSURE) trial assigned 516 patients to access site closure using a pure plug-based technique (MANTA, Teleflex) or a primary suture-based technique (ProGlide, Abbott Vascular). The principal finding of the overall study was that access-site or access-related complications were more common after the plug-based strategy compared to percutaneous closure with a suture-based strategy. In this predefined subgroup analysis, the overall cohort was split into patients with and without anterior calcification at the access site and divided by degree of calcification severity using the classification system developed in the MANTA vs. suture-based vascular closure after transcatHeter aortic valve replacement (MASH) trial. Differences in bleeding and vascular complications were compared. The primary endpoint consisted of access-site- or access-related major and minor vascular complications.There were more access-site-related major and minor vascular complications for patients with anterior wall vascular calcification and MASH severe calcification. No significant interaction with choice of closure technique in terms of access-site-related major and minor vascular complications was observed (odds ratio 1.70, 95% CI 0.77-3.78, p = 0.19 for the primary endpoint in plug- vs. suture-based strategy in patients with anterior calcification, odds ratio 1.78, 95% CI 0.56-5.65, p = 0.33 for primary endpoint in plug- vs. suture-based strategy with MASH severe calcification, pint = 0.97 for anterior calcification, pint = 0.95 for MASH severe calcification).The total number of vascular complications was found to be greater in the presence of anterior and MASH severe calcification. Overall, the presence of anterior or severe calcification does not significantly modify the efficacy of the suture-based strategy compared to the plug-based strategy.

  View details for DOI 10.1016/j.shj.2023.100236

  View details for PubMedID 38481717

  View details for PubMedCentralID PMC10927440

• Novel strategy to preserve valve morphology for 3-dimensional analysis of rat pulmonary valves JTCVS Structural and Endovascular Ono, Y., Shibata, M., Ma, X., Gil Antunano, M., Sewell, H. L., Frank , H., Riemer, R. K., Abilez, O. J. 2024; 1

  View details for DOI 10.1016/j.xjse.2024.100010

• Commissural Alignment of the ACURATE neo Valve in Transcatheter Aortic Valve Replacement. JACC. Cardiovascular interventions Kitamura, M., Wilde, J., Gohmann, R., Majunke, N., Gutberlet, M., Shibata, M., Kiefer, P., Desch, S., Thiele, H., Holzhey, D., Abdel-Wahab, M. 2021; 14 (15): 1740-1742

  View details for DOI 10.1016/j.jcin.2021.05.037

  View details for PubMedID 34353607

• Patient-Specific Neocommissural Alignment of the Evolut Valve: A Pilot Study in Transcatheter Aortic Valve-in-Valve Replacement. JACC. Cardiovascular interventions Kitamura, M., Wilde, J., Dumpies, O., Gutberlet, M., Gohmann, R., Shibata, M., Noack, T., Thiele, H., Holzhey, D., Abdel-Wahab, M. 2021; 14 (8): 934-936

  View details for DOI 10.1016/j.jcin.2020.12.002

  View details for PubMedID 33640386

• A novel method of vein cuff creation for below-knee femoropopliteal bypass with a prosthetic graft. Journal of vascular surgery cases and innovative techniques Sakamoto, S. I., Shibata, M., Takahashi, K. I., Morishima, M., Hiromoto, A., Nitta, T. 2020; 6 (2): 165-167

  Abstract

  Vein cuff anastomosis is beneficial in cases in which a prosthetic graft is anastomosed to a small and thickened peripheral artery. Various types of vein cuff are currently in use, although their design is insufficient when a size discrepancy exists between the two vessels and the angle of anastomosis requires adjustment. We report a case of a patient who underwent below-knee femoropopliteal bypass using a new design of vein cuff (boat-form vein cuff) that increases the ease of cuff creation and enables surgeons to adjust the anastomotic size and angle.

  View details for DOI 10.1016/j.jvscit.2020.02.002

  View details for PubMedID 32322767

  View details for PubMedCentralID PMC7160380

• Enhanced Sternal Healing Through Platelet-Rich Plasma and Biodegradable Gelatin Hydrogel. Tissue engineering. Part A Shibata, M., Takagi, G., Kudo, M., Kurita, J., Kawamoto, Y., Miyagi, Y., Kanazashi, M., Sakatani, T., Naito, Z., Tabata, Y., Miyamoto, M., Nitta, T. 2018; 24 (17-18): 1406-1412

  Abstract

  Platelet-rich plasma (PRP) contains numerous growth factors and promotes bone fracture healing. The aim of this study was to evaluate the effectiveness of the controlled release of PRP from biodegradable gelatin hydrogel for promoting healing in a rabbit ischemic sternal model. PRP was prepared from the whole blood of a Japanese white rabbit. Sixteen rabbits were randomized into four groups (each n = 4) and all underwent median sternotomy and bilateral internal thoracic artery removal. Before the sternum was closed, the following solutions were applied between the sternum incisions in three of the groups: 30 mg of gelatin hydrogel incorporating 300 μL of phosphate-buffered saline, 300 μL of a solution form of PRP, or 30 mg of gelatin hydrogel incorporating 300 μL of PRP (PRP + Gel). The fourth group acted as a control. Sternal healing was evaluated by histology and microcomputed tomography 7 days after the intervention. The PRP + Gel group showed a significantly higher proportion of fibrosis within the fracture area (an indicator of sternal healing) than the other groups and a significantly higher mean intensity of osteocalcin. These results indicate that the controlled release of PRP from locally applied gelatin hydrogel was markedly effective in enhancing sternal healing in the early postoperative period. This novel therapy could potentially help prevent complications, such as deep sternal wound infection and could result in early postoperative ambulation after median sternotomy.

  View details for DOI 10.1089/ten.TEA.2017.0505

  View details for PubMedID 29766749

• Intraoperative cardiac mapping in the treatment of an infant congenital fibroma. The Annals of thoracic surgery Sakamoto, S., Shibata, M., Murata, H., Nitta, T. 2015; 99 (3): 1064-6

  Abstract

  Surgical treatment for ventricular tachycardia associated with congenital cardiac tumors is rare. Intraoperative electroanatomic mapping was performed in a 23-month-old female infant to identify the arrhythmogenic substrate of the epicardium before tumor resection. Verification of the localized abnormal electrocardiogram on the tumor in the treatment of ventricular tachycardia was useful for successful partial resection and cryoablation of the giant fibroma.

  View details for DOI 10.1016/j.athoracsur.2014.04.130

  View details for PubMedID 25742832

• Acute type-A aortic dissection with patent false lumen through to the abdominal aorta: effects of a conventional elephant trunk on malperfusion syndromes and narrowed true lumen. Perfusion Imura, H., Tanoue, M., Shibata, M., Maruyama, Y., Shirakawa, M., Ochi, M. 2014; 29 (5): 417-24

  Abstract

  Narrowed true lumen and patent false lumen through to the terminal aorta is a high-risk condition for malperfusion syndromes (MS) in acute type-A aortic dissection. It is important to ascertain how the true and false lumens behave after surgery.We retrospectively investigated 45 patients with this pathology. The true lumen sizes at the narrowest levels above and below the superior mesenteric artery were followed by computed tomography after surgery (0-36 months).Thirty-seven MS were seen in 23 patients. Hospital mortality was 8.9%. The narrowed true lumen was not enlarged in the first 6 months with a patent false lumen. The elephant trunk procedure did not improve the true lumen size. An extremely narrowed (≤3 mm) true lumen was associated with a significantly high incidence of MS and mortality.High incidences of MS were observed in this particular pathology. An extremely narrowed true lumen was accompanied by a high incidence of MS and mortality.

  View details for DOI 10.1177/0267659113514787

  View details for PubMedID 24317275