Purpose: Obstructive intramural coronary amyloidosis is an unusual complication of systemic amyloidosis.
Subjects and methods: We review the characteristics of 11 patients seen at the Mayo Clinic (Rochester, Minnesota) from January 1, 1960, to June 1, 1999, with intramural cardiac amyloidosis diagnosed at autopsy or after examination of an explanted heart.
Results: Symptomatic ischemic heart disease resulting from obstructive intramural coronary amyloidosis was found in 11 patients (8 men, 3 women). The mean (+/-SD) age at the diagnosis of primary amyloidosis was 62 +/- 12 years. All patients had angina pectoris; angina was the presenting symptom of primary amyloidosis in 6 patients. Unstable coronary syndromes occurred in 7 patients and congestive heart failure in 8. New electrocardiographic abnormalities after the development of angina were common and included ischemic changes, bundle branch block, and dysrhythmias. Low voltage was seen in only 2 patients. All 7 patients who underwent coronary angiography had normal or clinically insignificant findings. Endomyocardial biopsy was performed on 4 patients; amyloid was found in 3 patients, none of whom had obstructive intramural coronary amyloidosis. The diagnosis of obstructive intramural coronary amyloidosis with associated myocardial injury was established only at autopsy or after examination of the explanted heart after cardiac transplantation. The mean time to death or cardiac transplantation after symptoms of cardiac ischemia developed was 18 +/- 20 months.
Conclusions: The diagnosis of ischemic heart disease resulting from obstructive intramural coronary amyloidosis is difficult to establish before death or cardiac transplantation. Although the condition has a poor prognosis, its accurate recognition may have therapeutic implications, because some patients may benefit from treatment, including systemic chemotherapy or cardiac transplantation.