Predictors of survival to orthotopic heart transplant in patients with light chain amyloidosis

Abstract

Background: Orthotopic heart transplant (OHT), followed by myeloablative chemotherapy and autologous stem cell transplant (ASCT), has been successful in the treatment of amyloid light-chain (AL) cardiac amyloidosis. The purpose of this study was to identify predictors of survival to OHT in patients with end-stage heart failure due to AL amyloidosis and compare post-OHT survival of cardiac amyloid patients with survival of other cardiomyopathy patients undergoing OHT.

Methods: From January 2000 to June 2011, 31 patients with end-stage heart failure secondary to AL amyloidosis were listed for OHT at Massachusetts General Hospital. Univariate and multivariate regression analyses identified predictors of survival to OHT. Kaplan-Meier analysis compared survival between the Massachusetts General Hospital amyloidosis patients and non-amyloid cardiomyopathy patients from the Scientific Registry of Transplant Recipients (SRTR).

Results: Low body mass index was the only predictor of survival to OHT in patients with end-stage heart failure caused by cardiac amyloidosis. Survival of cardiac amyloid patients who died before receiving a donor heart was only 63 ± 45 days after listing. Patients who survived to OHT received a donor organ at 53 ± 48 days after listing. Survival of AL amyloidosis patients on the waiting list was less than patients on the waiting list for all other non-amyloid diagnoses. The long-term survival of amyloid patients who underwent OHT was no different than the survival of non-amyloid, restrictive (p = 0.34), non-amyloid dilated (p = 0.34), or all non-amyloid cardiomyopathy patients (p = 0.22) in the SRTR database.

Conclusions: Amyloid patients who survive to OHT, followed by ASCT, have a survival rate similar to other cardiomyopathy patients undergoing OHT; however, 35% of the patients died awaiting OHT. The only predictor of survival to OHT in AL amyloidosis patients was a low body mass index, which correlated with a shorter time on the waiting list. To optimize the survival of these patients, access to donor organs must be improved.

Keywords: autologous stem cell transplant; body mass index; light-chain cardiac amyloidosis; orthotopic heart transplantation; survival.

Figure 1

Flow chart of all AL amyloidosis patients listed for OHT at Massachusetts General Hospital between 2000 and 2011. Eighteen of the thirty-one listed underwent transplant. Of those 18, 14 went on to ASCT, 1 died prior to ASCT and 3 were awaiting ASCT at the end of the study. Of the 14 that underwent both heart and stem cell transplant, 11 were alive at follow-up and 3 died after both procedures. Eleven patients listed for heart transplant did not survive to transplant. Two patients remain listed for transplant at the time of this analysis.

Figure 2

Kaplan-Meier survival curves for AL amyloidosis patients and non-amyloid patients waitlisted for heart transplantation at Massachusetts General Hospital from 2000–2011. The cumulative probability of survival on the transplant waitlist was lower for patients with AL amyloidosis than for patients with other diagnoses listed for transplant during the same time period (p<0.001).

Figure 3

Kaplan-Meier survival curves for amyloidosis patients who underwent heart transplant and a contemporaneous age-matched control group of patients from the Scientific Registry of Transplant Recipients (SRTR) database. There was no difference in survival between amyloidosis patients and non-amyloid restrictive cardiomyopathy patients (p=0.34), dilated cardiomyopathy patients (p=0.34), or all non-amyloid patients who underwent heart transplant (p=0.22).