The Impact of Ivabradine on Left Ventricular Reverse Remodeling in Nonischemic Dilated Cardiomyopathy (NIDCM) on Current Medical Therapy Era

Inclusion Criteria: 1. Diagnosed with non-ischemic dilated cardiomyopathy (NIDCM) by performing coronary artery imaging (coronary angiography, CT angiography, or SPECT scan) at the time of diagnosis of HFrEF 2. Sinus rhythm 3. Baseline LVEF of 40% or less (LVEF≤40%) 4. Patients containing baseline heart rate (HR) * In the Ivabradine group, baseline HR must be \>75 bpm at the time of ivabradine dosing. Exclusion Criteria: 1. Patients with confirmed ischemic cardiomyopathy (when stenosis of 75% or more of major coronary arteries is confirmed on coronary artery imaging or ischemic cardiomyopathy findings such as transmural LGE on cardiac MRI) 2. Heart failure with other etiologies (e.g., valvular heart disease, endocrine disease). 3. Previous recovery history of left ventricular systolic function (LVEF) 4. Cardiac resynchronization therapy (CRT) implantation 5. Persistent/permanent atrial fibrillation 7\) Contraindication to the administration of ivabradine according to the Summary of Product Characteristics (SmPC) * Hypersensitivity reactions * Symptomatic bradycardia or resting heart rate \< 75 bpm prior to treatment * Cardiogenic shock, acute myocardial infarction, severe hypotension (\< 90/50 mmHg), severe hepatic failure, sinus syndrome, atrial block, unstable or acute heart failure, pacemaker dependence (with pacing dominance), unstable angina, third degree atrioventricular block * Cytochrome P450 3A4 inhibitors: Azole class antifungals (ketoconazole,itraconazole), Macrolide class antibiotics (clarithromycin, erythromycin per os, josamycin, telithromycin), HIV protease inhibitors (nelfinavir, ritonavir), nefazodone or any concomitant use with verapamil or diltiazem (moderate CYP3A4 inhibitors with heart rate reducing properties).