Missed opportunity for anticoagulation in a patient with AL cardiac amyloidosis and rapidly progressive heart failure.

A previously healthy 65-year-old woman presented with progressive symptoms of heart failure. Low-voltage ECG and findings on echocardiography were concerning for infiltrative cardiomyopathy. Cardiac MRI showed biventricular late gadolinium enhancement, and endomyocardial biopsy confirmed monoclonal immunoglobulin light-chain (AL) amyloidosis. Bortezomib-based chemotherapy was initiated, but the patient continued to clinically deteriorate. She required hospital readmission after resuscitated out-of-hospital cardiac arrest attributed to progressive conduction disease, and a permanent pacemaker was implanted. Chest CT angiography showed a small subsegmental pulmonary embolism (PE), but anticoagulation was withheld as her lower extremity Doppler was negative. One month later, another pulseless electrical arrest occurred, due to massive PE. Thereafter, she had refractory class IV congestive heart failure with severe right ventricular dysfunction, and was deemed unsuitable for stem-cell or heart transplantation. This case highlights the predilection for thromboembolism in AL cardiac amyloidosis.