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Ken Okumura

Bio: Ken Okumura is an academic researcher from Hirosaki University. The author has contributed to research in topics: Atrial fibrillation & Warfarin. The author has an hindex of 65, co-authored 561 publications receiving 18237 citations. Previous affiliations of Ken Okumura include Harvard University & Kumamoto University.


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Journal ArticleDOI
TL;DR: Examination of the sources and mechanisms of the secretion of BNP in comparison with those of ANP in control subjects and in patients with heart failure concludes that BNP is secreted mainly from the left ventricle in normal adult humans as well as in Patients with left ventricular dysfunction.
Abstract: BACKGROUNDB-type or brain natriuretic peptide (BNP) is a novel natriuretic peptide secreted from the heart that forms a peptide family with A-type or atrial natriuretic peptide (ANP), and its plasma level has been shown to be increased in patients with congestive heart failure. This study was designed to examine the sources and mechanisms of the secretion of BNP in comparison with those of ANP in control subjects and in patients with heart failure.METHODS AND RESULTSWe measured the plasma levels of BNP as well as ANP in 16 patients with dilated cardiomyopathy (11 men and 5 women; mean age, 59 years) and 18 control subjects (9 men and 9 women; mean age, 54 years) by sampling blood from the femoral vein, the aortic root, the anterior interventricular vein (AIV), and the coronary sinus using the newly developed immunoradiometric assay systems. In the control subjects, there was no significant difference in the plasma ANP level between the aortic root and the AIV (24.0 +/- 5.2 pg/mL versus 32.2 +/- 17.0 pg/mL...

1,348 citations

Journal ArticleDOI
TL;DR: It is concluded that plasma levels of BNP mainly reflect the degree of ventricular overload and that the secretion patterns of ANP and BNP vary with underlying cardiac disorders of CHF with different degrees of overload in atria and ventricles.
Abstract: BACKGROUNDThe plasma levels of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) are increased in relation to the severity of congestive heart failure (CHF). This study was designed to examine whether the secretion patterns of ANP and BNP vary with underlying cardiac disorders of CHF with different degrees of overload in atria and ventricles.METHODS AND RESULTSWe measured plasma levels of ANP and BNP in the aorta in 20 patients with mitral stenosis (MS) in whom atria are mainly overloaded, 30 patients with dilated cardiomyopathy (DCM) in whom both atria and ventricles are overloaded, and 20 control subjects during cardiac catheterization. Pulmonary capillary wedge pressure (PCWP) was significantly higher in the MS and DCM groups (16.7 +/- 4.7 mm Hg and 15.1 +/- 7.7 mm Hg, respectively) than in the control group (7.2 +/- 1.1 mm Hg, p < 0.01), whereas there was no significant difference between the MS and DCM groups. Left ventricular end-diastolic pressure (LVEDP) was significantly higher...

617 citations

Journal ArticleDOI
01 Oct 2017-Europace
TL;DR: This 2017 Consensus Statement is to provide a state-of-the-art review of the field of catheter and surgical ablation of AF and to report the findings of a writing group, convened by these five international societies.
Abstract: During the past three decades, catheter and surgical ablation of atrial fibrillation (AF) have evolved from investigational procedures to their current role as effective treatment options for patients with AF. Surgical ablation of AF, using either standard, minimally invasive, or hybrid techniques, is available in most major hospitals throughout the world. Catheter ablation of AF is even more widely available, and is now the most commonly performed catheter ablation procedure. In 2007, an initial Consensus Statement on Catheter and Surgical AF Ablation was developed as a joint effort of the Heart Rhythm Society (HRS), the European Heart Rhythm Association (EHRA), and the European Cardiac Arrhythmia Society (ECAS).1 The 2007 document was also developed in collaboration with the Society of Thoracic Surgeons (STS) and the American College of Cardiology (ACC). This Consensus Statement on Catheter and Surgical AF Ablation was rewritten in 2012 to reflect the many advances in AF ablation that had occurred in the interim.2 The rate of advancement in the tools, techniques, and outcomes of AF ablation continue to increase as enormous research efforts are focused on the mechanisms, outcomes, and treatment of AF. For this reason, the HRS initiated an effort to rewrite and update this Consensus Statement. Reflecting both the worldwide importance of AF, as well as the worldwide performance of AF ablation, this document is the result of a joint partnership between the HRS, EHRA, ECAS, the Asia Pacific Heart Rhythm Society (APHRS), and the Latin American Society of Cardiac Stimulation and Electrophysiology (Sociedad Latinoamericana de Estimulacion Cardiaca y Electrofisiologia [SOLAECE]). The purpose of this 2017 Consensus Statement is to provide a state-of-the-art review of the field of catheter and surgical ablation of AF and to report the findings of a writing group, convened by these five international societies. The writing group is charged with defining the indications, techniques, and outcomes of AF ablation procedures. Included within this document are recommendations pertinent to the design of clinical trials in the field of AF ablation and the reporting of outcomes, including definitions relevant to this topic. The writing group is composed of 60 experts representing 11 organizations: HRS, EHRA, ECAS, APHRS, SOLAECE, STS, ACC, American Heart Association (AHA), Canadian Heart Rhythm Society (CHRS), Japanese Heart Rhythm Society (JHRS), and Brazilian Society of Cardiac Arrhythmias (Sociedade Brasileira de Arritmias Cardiacas [SOBRAC]). All the members of the writing group, as well as peer reviewers of the document, have provided disclosure statements for all relationships that might be perceived as real or potential conflicts of interest. All author and peer reviewer disclosure information is provided in Appendix A and Appendix B. In writing a consensus document, it is recognized that consensus does not mean that there was complete agreement among all the writing group members. Surveys of the entire writing group were used to identify areas of consensus concerning performance of AF ablation procedures and to develop recommendations concerning the indications for catheter and surgical AF ablation. These recommendations were systematically balloted by the 60 writing group members and were approved by a minimum of 80% of these members. The recommendations were also subject to a 1-month public comment period. Each partnering and collaborating organization then officially reviewed, commented on, edited, and endorsed the final document and recommendations. The grading system for indication of class of evidence level was adapted based on that used by the ACC and the AHA.3,4 It is important to state, however, that this document is not a guideline. The indications for catheter and surgical ablation of AF, as well as recommendations for procedure performance, are presented with a Class and Level of Evidence (LOE) to be consistent with what the reader is familiar with seeing in guideline statements. A Class I recommendation means that the benefits of the AF ablation procedure markedly exceed the risks, and that AF ablation should be performed; a Class IIa recommendation means that the benefits of an AF ablation procedure exceed the risks, and that it is reasonable to perform AF ablation; a Class IIb recommendation means that the benefit of AF ablation is greater or equal to the risks, and that AF ablation may be considered; and a Class III recommendation means that AF ablation is of no proven benefit and is not recommended. The writing group reviewed and ranked evidence supporting current recommendations with the weight of evidence ranked as Level A if the data were derived from high-quality evidence from more than one randomized clinical trial, meta-analyses of high-quality randomized clinical trials, or one or more randomized clinical trials corroborated by high-quality registry studies. The writing group ranked available evidence as Level B-R when there was moderate-quality evidence from one or more randomized clinical trials, or meta-analyses of moderate-quality randomized clinical trials. Level B-NR was used to denote moderate-quality evidence from one or more well-designed, well-executed nonrandomized studies, observational studies, or registry studies. This designation was also used to denote moderate-quality evidence from meta-analyses of such studies. Evidence was ranked as Level C-LD when the primary source of the recommendation was randomized or nonrandomized observational or registry studies with limitations of design or execution, meta-analyses of such studies, or physiological or mechanistic studies of human subjects. Level C-EO was defined as expert opinion based on the clinical experience of the writing group. Despite a large number of authors, the participation of several societies and professional organizations, and the attempts of the group to reflect the current knowledge in the field adequately, this document is not intended as a guideline. Rather, the group would like to refer to the current guidelines on AF management for the purpose of guiding overall AF management strategies.5,6 This consensus document is specifically focused on catheter and surgical ablation of AF, and summarizes the opinion of the writing group members based on an extensive literature review as well as their own experience. It is directed to all health care professionals who are involved in the care of patients with AF, particularly those who are caring for patients who are undergoing, or are being considered for, catheter or surgical ablation procedures for AF, and those involved in research in the field of AF ablation. This statement is not intended to recommend or promote catheter or surgical ablation of AF. Rather, the ultimate judgment regarding care of a particular patient must be made by the health care provider and the patient in light of all the circumstances presented by that patient. The main objective of this document is to improve patient care by providing a foundation of knowledge for those involved with catheter ablation of AF. A second major objective is to provide recommendations for designing clinical trials and reporting outcomes of clinical trials of AF ablation. It is recognized that this field continues to evolve rapidly. As this document was being prepared, further clinical trials of catheter and surgical ablation of AF were under way.

521 citations

Journal ArticleDOI
TL;DR: Long-term prognosis for patients with variant angina is relatively good and that use of calcium antagonists improves it, and multivariate analysis using the Cox proportional hazards model showed that intake of calcium antagonist, extent and severity of coronary artery disease, and ST segment elevation in both the anterior and inferior leads were significant independent predictors of survival without myocardial infarction.
Abstract: Two hundred forty-five patients with variant angina were followed for an average of 80.5 months (range, 36-184 months). Survival rate at 1, 3, 5, and 10 years was 98%, 97%, 97%, and 93%, respectively. Survival rate without myocardial infarction at 1, 3, 5, and 10 years was 86%, 85%, 83%, and 81%, respectively. By univarite analysis, ST segment elevation in both the anterior and inferior electrocardiographic leads was the most important factor influencing survival, followed by use of calcium antagonists, left ventricular function, smoking, and alcohol intake. The variables that significantly correlated with survival without myocardial infarction were use of calcium antagonists, left ventricular function, extent and severity of coronary artery disease, coronary artery bypass surgery, and disease activity. Multivariate analysis using the Cox proportional hazards model showed that intake of calcium antagonists, extent and severity of coronary artery disease, and ST segment elevation in both the anterior and inferior leads were significant independent predictors of survival without myocardial infarction. We conclude that long-term prognosis for patients with variant angina is relatively good and that use of calcium antagonists improves it.

415 citations

Journal ArticleDOI
TL;DR: This English language document is a revised digest version of Guidelines for the Diagnosis and Treatment of Acute and Chronic Heart Failure (JCS 2017/JHFS 2017) reported at the Japanese Circulation Society Joint Working Groups performed in 2017.
Abstract: J-STAGE Advance Publication released online September 10, 2019 Mailing address: Scientific Committee of the Japanese Circulation Society, 18F Imperial Hotel Tower, 1-1-1 Uchisaiwai-cho, Chiyoda-ku, Tokyo 100-0011, Japan. E-mail: meeting@j-circ.or.jp This English language document is a revised digest version of Guidelines for the Diagnosis and Treatment of Acute and Chronic Heart Failure (JCS 2017/JHFS 2017) reported at the Japanese Circulation Society Joint Working Groups performed in 2017 (Website: http://www.j-circ.or.jp/guideline/pdf/JCS2017_tsutsui_d.pdf). Joint Working Groups: The Japanese Circulation Society; the Japanese Heart Failure Society; the Japanese Association for Thoracic Surgery; the Japanese Society of Hypertension; the Japanese Society of Echocardiography; the Japanese Society for Cardiovascular Surgery; the Japanese College of Cardiology; the Japanese Association of Cardiac Rehabilitation; the Japan Society of Ultrasonics in Medicine; the Japan Diabetes Society; the Japanese Heart Rhythm Society; “the Study Group on Idiopathic Cardiomyopathy” supported by the Health and Labor Sciences Research Grant on Intractable Diseases; and “the Study Group on the Multi-center Observational Study of Dilatedphase Hypertrophic Cardiomyopathy”, supported by the “Practical Research Project for Rare/ intractable Diseases by the Japan Agency for Medical Research and Development”. ISSN-1346-9843 All rights are reserved to the Japanese Circulation Society. For permissions, please e-mail: cj@j-circ.or.jp JCS 2017/JHFS 2017 Guideline on Diagnosis and Treatment of Acute and Chronic Heart Failure ― Digest Version ―

390 citations


Cited by
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Journal ArticleDOI
TL;DR: WRITING GROUP MEMBERS Emelia J. Benjamin, MD, SCM, FAHA Michael J. Reeves, PhD Matthew Ritchey, PT, DPT, OCS, MPH Carlos J. Jiménez, ScD, SM Lori Chaffin Jordan,MD, PhD Suzanne E. Judd, PhD
Abstract: WRITING GROUP MEMBERS Emelia J. Benjamin, MD, SCM, FAHA Michael J. Blaha, MD, MPH Stephanie E. Chiuve, ScD Mary Cushman, MD, MSc, FAHA Sandeep R. Das, MD, MPH, FAHA Rajat Deo, MD, MTR Sarah D. de Ferranti, MD, MPH James Floyd, MD, MS Myriam Fornage, PhD, FAHA Cathleen Gillespie, MS Carmen R. Isasi, MD, PhD, FAHA Monik C. Jiménez, ScD, SM Lori Chaffin Jordan, MD, PhD Suzanne E. Judd, PhD Daniel Lackland, DrPH, FAHA Judith H. Lichtman, PhD, MPH, FAHA Lynda Lisabeth, PhD, MPH, FAHA Simin Liu, MD, ScD, FAHA Chris T. Longenecker, MD Rachel H. Mackey, PhD, MPH, FAHA Kunihiro Matsushita, MD, PhD, FAHA Dariush Mozaffarian, MD, DrPH, FAHA Michael E. Mussolino, PhD, FAHA Khurram Nasir, MD, MPH, FAHA Robert W. Neumar, MD, PhD, FAHA Latha Palaniappan, MD, MS, FAHA Dilip K. Pandey, MBBS, MS, PhD, FAHA Ravi R. Thiagarajan, MD, MPH Mathew J. Reeves, PhD Matthew Ritchey, PT, DPT, OCS, MPH Carlos J. Rodriguez, MD, MPH, FAHA Gregory A. Roth, MD, MPH Wayne D. Rosamond, PhD, FAHA Comilla Sasson, MD, PhD, FAHA Amytis Towfighi, MD Connie W. Tsao, MD, MPH Melanie B. Turner, MPH Salim S. Virani, MD, PhD, FAHA Jenifer H. Voeks, PhD Joshua Z. Willey, MD, MS John T. Wilkins, MD Jason HY. Wu, MSc, PhD, FAHA Heather M. Alger, PhD Sally S. Wong, PhD, RD, CDN, FAHA Paul Muntner, PhD, MHSc On behalf of the American Heart Association Statistics Committee and Stroke Statistics Subcommittee Heart Disease and Stroke Statistics—2017 Update

7,190 citations

Journal ArticleDOI
TL;DR: This document summarizes current research, plans, and recommendations for future research, as well as providing a history of the field and some of the techniques used, currently in use, at the National Institutes of Health.
Abstract: Jeffrey L. Anderson, MD, FACC, FAHA, Chair Jonathan L. Halperin, MD, FACC, FAHA, Chair-Elect Nancy M. Albert, PhD, RN, FAHA Biykem Bozkurt, MD, PhD, FACC, FAHA Ralph G. Brindis, MD, MPH, MACC Mark A. Creager, MD, FACC, FAHA[#][1] Lesley H. Curtis, PhD, FAHA David DeMets, PhD[#][1] Robert A

6,967 citations

Journal ArticleDOI
TL;DR: The current guidelines for the management of acute coronary syndromes in patients presenting without persistent ST-segment elevation are based on the findings of the ESC Task Force on 12 March 2015.
Abstract: ESC Guidelines for the management of acute coronary syndromes in patients presenting without persistent ST-segment elevation : The Task Force for the management of acute coronary syndromes (ACS) in patients presenting without persistent ST-segment elevation of the European Society of Cardiology (ESC).

6,866 citations

Journal ArticleDOI
TL;DR: Author(s): Writing Group Members; Mozaffarian, Dariush; Benjamin, Emelia J; Go, Alan S; Arnett, Donna K; Blaha, Michael J; Cushman, Mary; Das, Sandeep R; de Ferranti, Sarah; Despres, Jean-Pierre; Fullerton, Heather J; Howard, Virginia J; Huffman, Mark D; Isasi, Carmen R; Jimenez, Monik C; Judd, Suzanne
Abstract: Author(s): Writing Group Members; Mozaffarian, Dariush; Benjamin, Emelia J; Go, Alan S; Arnett, Donna K; Blaha, Michael J; Cushman, Mary; Das, Sandeep R; de Ferranti, Sarah; Despres, Jean-Pierre; Fullerton, Heather J; Howard, Virginia J; Huffman, Mark D; Isasi, Carmen R; Jimenez, Monik C; Judd, Suzanne E; Kissela, Brett M; Lichtman, Judith H; Lisabeth, Lynda D; Liu, Simin; Mackey, Rachel H; Magid, David J; McGuire, Darren K; Mohler, Emile R; Moy, Claudia S; Muntner, Paul; Mussolino, Michael E; Nasir, Khurram; Neumar, Robert W; Nichol, Graham; Palaniappan, Latha; Pandey, Dilip K; Reeves, Mathew J; Rodriguez, Carlos J; Rosamond, Wayne; Sorlie, Paul D; Stein, Joel; Towfighi, Amytis; Turan, Tanya N; Virani, Salim S; Woo, Daniel; Yeh, Robert W; Turner, Melanie B; American Heart Association Statistics Committee; Stroke Statistics Subcommittee

6,181 citations