補助人工心臓治療における最適な患者選択方法の多面的な検討 : 新たなスコアリング構築の試み

学位の種別:課程博士University of Tokyo(東京大学

Ischemic Etiology and Clinical Outcomes Following Cardiac Resynchronization Therapy

Optimal patient selection for cardiac resynchronization therapy is crucial. There are several concerns that allow to better clarify the association between the ischemic etiology of heart failure and the response to cardiac resynchronization therapy. The type of ischemic coronary disease has an impact on the responses to cardiac resynchronization therapy. The prognostic impact of cardiac resynchronization therapy on cardiac death including heart transplantation and durable ventricular assist device implantation is another concern

Association between Lung Fluid Levels Estimated by Remote Dielectric Sensing Values and Invasive Hemodynamic Measurements

Background: Remote dielectric sensing (ReDS™) is an electromagnetic-based technology used to noninvasively measure lung fluid levels. The association between ReDS values and invasively measured hemodynamics, particularly among those with small physics, remains unknown. Methods: Consecutive patients with chronic heart failure who were admitted to our institute and underwent invasive right heart catheterization as well as simultaneous ReDS measurement at clinically stable conditions between September and November 2021 were prospectively included. The colinearity between ReDS values and pulmonary capillary wedge pressure was studied. Results: In total, 30 patients (median 79 (73, 84) years old, 13 men) were included. Median ReDS value was 26% (22%, 28%). ReDS values had a moderate collinearity with pulmonary capillary wedge pressure (r = 0.698, p < 0.001), even among those with a body height < 155 cm. ReDS values with a cutoff of 28% predicted a pulmonary capillary wedge pressure > 15 mmHg with sensitivity 0.70 and specificity 0.75. Conclusions: An electromagnetic-based engineering ReDS might be a potential tool to estimate cardiac pressure in patients with heart failure, including those with small physics

Clinical Implications of Ivabradine in the Contemporary Era

Ivabradine is a recently introduced inhibitor of the If ion channel, which exhibits the capacity to reduce heart rate while preserving hemodynamic stability. At present, ivabradine finds its clinical indication in patients suffering from heart failure with reduced ejection fraction and maintaining a relative sinus rhythm refractory to beta-blockers. To optimize heart rate control, it is recommended to pursue an aggressive up-titration of ivabradine. This approach may ameliorate tachycardia-induced hypotension by incrementally enhancing cardiac output and allow further up-titration of agents aimed at ameliorating heart failure, such as beta-blockers. Both the modulation of heart rate itself and the up-titration of agents targeting heart failure lead to cardiac reverse remodeling, consequently culminating in a subsequent reduction in mortality and morbidity. A novel overlap theory that our team proposed recently has emerged in recent times. Under trans-mitral Doppler echocardiography, the E-wave and A-wave closely juxtapose one another without any overlapping at the optimal heart rate. Employing echocardiography-guided ivabradine for heart-rate modulation to minimize the overlap between the E-wave and A-wave appears to confer substantial benefits to patients with heart failure. This approach facilitates superior cardiac reverse remodeling and yields more favorable clinical outcomes when compared to those patients who do not receive echocardiography-guided care. The next pertinent issue revolves around the potential expansion of ivabradine’s clinical indications to encompass a broader spectrum of diseases. It is imperative to acknowledge that ivabradine may not yield clinically significant benefits in patients afflicted by heart failure with preserved ejection fraction, acute heart failure, sepsis, or stable angina. An important fact yet to be explored is the clinical applicability of ivabradine in patients with atrial fibrillation, a concern that beckons future investigation. In this review, the concept of overlap theory it introduced, along with its application to expand the indication of ivabradine and the overlap theory-guided optimal ivabradine therapy

Change in Lung Fluid Volume during Exercise in Patients with Exercise-Induced Mitral Regurgitation

Exercise-induced mitral regurgitation (MR) can be diagnosed during stress echocardiography testing. Remote dielectric sensing (ReDSTM) is a noninvasive electromagnetic-based modality to measure lung fluid levels. The change in lung fluid levels in patients with MR during stress echocardiography remains unknown. Patients with symptomatic MR at baseline and suspected worsening exercise-induced MR underwent stress echocardiography. ReDS values were measured before and after the tests. A total of four patients (ages ranging between 74 and 84 years old, three women) underwent stress echocardiography testing using a bicycle ergometer. In patient A, MR effective regurgitant orifice area (EROA) remained unchanged and ReDS values decreased. EROA increased significantly with a small incremental change in ReDS values in patient B and patient C, who underwent valve repair with MitraClip later. Patient D had a mild increase in MR EROA but a considerable increase in ReDS values (from 22% to 32%), and eventually received valve repair with MitraClip. The ReDS system may be a complementary tool to conventional stress echocardiography in the evaluation of clinically significant MR and considering mitral valve intervention