A 55-year-old man with a 12-year history of type 2 diabetes and hypertension presents to the emergency department with progressive dyspnea on exertion over 3 months. He reports orthopnea and paroxysmal nocturnal dyspnea for 2 weeks. Physical examination reveals blood pressure 168/98 mmHg, heart rate 108/min, respiratory rate 24/min, and oxygen saturation 91% on room air. Jugular venous pressure is elevated at 8 cm H₂O. Cardiac auscultation demonstrates an S3 gallop and bilateral basilar crackles. Lower extremity examination shows 2+ pitting edema bilaterally with intact dorsalis pedis and posterior tibial pulses. Laboratory studies show BNP 520 pg/mL (normal <100), troponin I 0.02 ng/mL (normal <0.04), and creatinine 1.4 mg/dL. Chest X-ray demonstrates pulmonary edema with normal cardiac silhouette borders. Transthoracic echocardiography reveals a dilated left ventricle (end-diastolic dimension 62 mm), global hypokinesis, and left ventricular ejection fraction of 32%. Coronary angiography shows patent coronary arteries without significant stenosis. Which of the following is the most likely diagnosis?

1. A)Acute myocardial infarction with mechanical complication
2. B)Restrictive cardiomyopathy secondary to amyloidosis
3. C)Dilated cardiomyopathyGABARITO
4. D)Hypertrophic cardiomyopathy with apical involvement
5. E)Constrictive pericarditis