A 58-year-old man comes to the physician because of a 3-month history of shortness of breath. He has had orthopnea, paroxysmal nocturnal dyspnea and peripheral edema. He has a history of sarcoidosis. His pulse is 100/min and regular, respirations are 20/min, and blood pressure is 130/75 mm Hg. There are jugular venous pulsations 6 cm above the sternal angle with a prominent y descent. Crackles are heard at both lung bases. Cardiac examination shows an S3. There is 2+ pretibial edema bilaterally. An echocardiogram shows thickening of both ventricles and septum with normal pericardial thickness. Which of the following is the most likely diagnosis?