Cardiac transplantation outcomes in patients with amyloid cardiomyopathy

Amyloid cardiomyopathy (ACM) is a progressive and life-threatening disease caused by abnormal protein deposits within cardiac tissue. The most common forms of ACM are caused by immunoglobulin derived light chains (AL) and transthyretin (TTR). Orthotopic heart transplantation (OHT) remains the definitive treatment for patients with end stage heart failure. In this study, we perform a contemporary multicenter analysis evaluating post OHT survival in patients with ACM.

We conducted a multicenter analysis of 40,044 adult OHT recipients captured in the United Network for Organ Sharing (UNOS) registry from 1987-2018. Patients were characterized as ACM or non-ACM. Baseline characteristics were obtained, and summary characteristics were calculated. Outcomes of interest included post-transplant survival, infection, treated rejection, and the ability to return to work. Racial differences in OHT survival were also analyzed. Unadjusted associations between ACM and non-ACM survival were determined using the Kaplan-Meier estimations and confounding was addressed using multivariable Cox proportional hazards models.

Three hundred ninety-eight patients with a diagnosis of ACM were identified of which 313 underwent heart only OHT. ACM patients were older (61 vs 53; P < .0001) and had a higher proportion of African Americans (30.7% vs 17.6%; P < .0001). Median survival for ACM was 10.2 years vs 12.5 years in non-ACM (P = .01). After adjusting for confounding, ACM patients had a higher likelihood of death post-OHT (HR 1.39 CI: 1.14, 1.70; P = .001). African American ACM patients had a higher likelihood of survival compared to White ACM patients (HR 0.51 CI 0.31-0.85; P = .01). No difference was observed in episodes of treated rejection (OR 0.63 CI 0.23, 1.78; P = .39), hospitalizations for infections (OR 1.24 CI: 0.85, 1.81; P = .26), or likelihood of returning to work for income (OR 1.23 CI: 0.84, 1.80; P = .30).

In this analysis of OHT in ACM, ACM was associated with a higher likelihood of post-OHT mortality. Racial differences in post-OHT were observed with African American patients with ACM having higher likelihood of survival compared to White patients with ACM. No differences were observed in episodes of treated rejection, hospitalization for infection, or likelihood to return to work for income.