Characteristics and outcomes of cardiac amyloid disease after heart transplantation: A systematic review and meta-analysis

Abstract

Purpose

Patients with systemic amyloidosis with cardiac involvement require careful selection for heart transplantation (HTx) due to the associated poor outcomes. Large databases do not provide sufficient granularity to allow for differentiation between its major subtypes [light-chain (AL) and transthyretin (ATTR) amyloidosis]. We sought to pool the existing data on amyloidosis patients undergoing HTx, and perform stratified analysis based on its major subtypes.

Methods

Electronic search identified adult patients with amyloidosis undergoing HTx. Cohort-level data for 340 patients from 19 studies were extracted and analyzed. Patients were categorized based on amyloid subtype into AL and ATTR groups.

Results

AL amyloidosis was diagnosed at an earlier age compared to ATTR [53 (95 % CI 48; 57) years vs. 63 (55; 71) years, p = 0.03], with greater incidence in the Caucasian population [75 % (60; 87) vs. 39 % (21; 59), p ≤0.01]. Females comprised 33 % (25; 41) of the patients with greater preponderance in AL group [41 % (33; 48) vs. 21 % (8; 36), p = 0.02]. AL patients also had higher involvement of ≥two organs [50 % (29; 70) vs. 15 % (3; 32), p = 0.01]. GI involvement [25 % (6; 50) vs. 0 % (0; 8), p = 0.02], and renal involvement [20 % (8; 34) vs. 0 % (0; 2), p < 0.01] were virtually limited to AL, while ATTR patients had more implantable cardioverter defibrillators placed [64 % (34; 90) vs. 15 % (6; 28), p < 0.01] and trended towards greater incidence of neuropathy [24 % (9; 42) vs. 9 % (2; 19), p = 0.07]. The AL group had a significantly higher incidence of recurrent amyloidosis [16 % (7; 27) vs. 0 % (0; 0), p ≤0.01]. Pooled Kaplan-Meier survival analysis showed worse long-term survival in the AL group (p = 0.02).

Conclusion

Patients with AL amyloidosis showed more widespread systemic involvement and worse long-term survival after HTx compared to patients with ATTR amyloidosis. Protocols for mitigating the recurrence of AL amyloidosis are needed to improve survival in this high-risk subtype.