A patient with multiple myeloma develops amyloidosis. What is the most serious cardiac complication of cardiac amyloidosis?

Correct answer: C. Heart failure

• A. Incorrect. Hypertension is not a direct complication of cardiac amyloidosis.
• B. Incorrect. Coronary artery disease is atherosclerotic in nature and is not directly caused by amyloid deposition.
• C. CORRECT. Cardiac amyloidosis causes amyloid protein deposits to infiltrate the myocardium, leading to restrictive cardiomyopathy. The heart becomes progressively stiff and loses its ability to fill adequately (diastolic dysfunction), ultimately leading to heart failure — the primary and most serious cardiac complication of amyloidosis.
• D. Incorrect. Mitral valve prolapse is a separate structural cardiac condition unrelated to amyloidosis.