Patient Management and Follow-up

All baseline clinical measurements were made just prior to EMB. Patients underwent echocardiography, including color Doppler examination; coronary angiography; and routine laboratory testing. EMB was indicated for pathologic diagnosis only when chronic heart failure was stable and medically controlled. We followed patients for 12 months after EMB or the occurrence of a cardiac event, whichever came first. We collected follow-up data from the medical records for routine outpatient clinic visits.

In this study, we defined cardiac event as VAD implantation or death from heart failure. Indications for VAD implantation were based on Japan Circulation Society guidelines [19]. In short, they included irreversible end-stage heart failure with NYHA class IV disease by symptoms and imminent or already existing end-organ dysfunction despite optimal medical therapy, including dependent of inotropic agents. Hemodynamic criteria for VAD implantation included cardiac index ≤2.0 L/min/m², systolic blood pressure ≤80 mmHg, and left or right atrium pressure ≥20 mmHg.