A 60-year-old man visits the physician because of worsening cough and orthopnea. On physical examination, he has dullness to percussion at the lung bases and diffuse crackles in the upper lung fields. He is afebrile. Echocardiography shows marked left ventricular hypertrophy and severe aortic stenosis. The remaining cardiac valves are normal. A coronary angiogram shows no significant coronary arterial narrowing. Which of the following conditions best accounts for these findings? (A) Diabetes mellitus (B) Marfan syndrome (C) Bicuspid aortic valve (D) Systemic hypertension (E) Infective endocarditis