Prevalence of Cardiac Thrombi in Cardiac Amyloidosis

Cardiac amyloidosis (CA) is an infiltrative disease characterized by deposits of amyloid proteins of genetic or acquired origin (often in elderly patients), leading to heart failure and arrhythmias. More than 98% of currently diagnosed cases of cardiac amyloidosis result from fibrils composed of monoclonal immunoglobulin light chains (AL) or transthyretin (ATTR), in its hereditary (ATTRv) or acquired (ATTRwt) form.

Its prevalence is rising sharply due to an aging population and improved diagnostic techniques. Atrial fibrillation is responsible, in particular, for heart failure, arrhythmias, conduction disorders, and ischemic strokes, and is associated with significant morbidity and mortality. These patients have a much higher-than-normal risk of stroke because they are in a procoagulant state in the left atrium, even in the absence of atrial fibrillation. Intracardiac thrombi (ICTs) are present in 28% of patients with AC requiring cardioversion, compared with 2.5% of patients without AC, 50% of whom are on anticoagulants.

It has also been shown that the CHA2DS2-VASc score is not effective in predicting thromboembolic risk, and that direct oral anticoagulants (DOACs) are as effective as vitamin K antagonists (VKAs) in preventing embolisms.

The prevalence and factors associated with the development of intracardiac thrombi in patients with cardiac amyloidosis are unknown, as the available retrospective studies focused only on selected high-risk patients. Furthermore, tafamidis is now available to stabilize the course of cardiac amyloidosis and improve prognosis, but its effect on thromboembolic risk remains unknown.