Abstract 16603: Appropriate Timing of Pacemaker Implantation in Patients With Wild-Type and Variant Amyloidogenic Transthyretin Cardiac Amyloidosis

Abstract

Background and Objectives: It has been shown that cardiac conduction disorders can be seen in patients with wild-type amyloidogenic transthyretin (ATTRwt) and variant ATTR (ATTRv) cardiac amyloidosis. However, its appropriate timing of pacemaker implantation has not been clarified yet. Methods and Results: The consecutive 100 patients with ATTRwt cardiac amyloidosis who diagnosed by myocardium biopsy and/or technetium-99m-pyrophosphate scintigraphy and 62 patients with ATTRv cardiac amyloidosis who diagnosed by means of genetic screening were included in this study. In patients with ATTRwt cardiac amyloidosis, 21 patients have normal conduction at the time of diagnosis. However, conduction disorder had seen in only 5 patient (first degree atrioventricular block (AVB); 4 patients, complete AVB; 1 patients) and only one patient underwent cardiac implantable electric device (CIED) implantation during follow-up period. On the other hand, in patients with ATTRv cardiac amyloidosis, 36 patients have normal conduction at the time of diagnosis. However, conduction disorder had seen in 13 patient (first degree AVB; 8 patients, second degree AVB; 3 patients, trifascicular block; 1 patients, complete AVB; 1 patients) (5/21 vs 13/36, p=0.335) and 6 patients underwent CIED implantation during follow-up period (1/21 vs 6/36, p=0.186). Furthermore, in ATTRwt cardiac amyloidosis, 10 patients (first degree AVB; 2 patients, second degree AVB; 1 patient, trifascicular block; 7 patients) had underwent CIED implantation because of cardiac conduction disorders and/or prevention of sudden cardiac death. However, only 4 patients with trifascicular block progressed to complete AVB.On the other hand, In ATTRv cardiac amyloidosis, 14 patients (first degree AVB; 2 patients, second degree AVB; 4 patient, trifascicular block; 8 patients) had underwent CIED implantation for same reason. However, only 3 patients with trifascicular block progressed to complete AVB. Conclusions: Patients with ATTRv cardiac amyloidosis were more likely to progress conduction disorders than those with ATTRwt cardiac amyloidosis. However, prophylactic pacemaker implantation might had not need in both ATTRwt and ATTRv patients with first or second degree AVB.