Recent improvements in survival in primary systemic amyloidosis and the importance of an early mortality risk score

Objective: To examine whether the outcome of patients with primary systemic amyloidosis (AL) has improved over time and to identify predictors of early mortality in patients with AL. Patients and Methods: We studied 2 separate cohorts of patients. The first cohort, consisting of 1998 patients with AL seen at Mayo Clinic between January 1977 and August 2006, was used to examine the trends in overall survival (OS) from diagnosis during this 30-year period. The second cohort, consisting of 313 patients seen between September 2006 and August 2009, was used to validate a model for predicting early mortality. Results: The 4-year OS from diagnosis improved during each decade of follow-up: 21%, 24%, and 33%, respectively, for the periods 1977-1986, 1987-1996, and 1997-2006 (P<001). Within the last group (1997-2006), 4-year OS during 1997-1999, 2000-2002, and 2003-2006 was 28%, 30%, and 42%, respectively (P=.02). However, the 1-year mortality remained high during the 30-year period. A risk stratification score using cardiac troponin T, N-terminal probrain natriuretic peptide, and uric acid identified patients at risk of early mortality. The 1-year mortality with 0, 1, 2, or 3 risk factors was 19%, 37%, 61%, and 80%, respectively, in this training cohort of 459 patients. This was confirmed in a validation cohort of 313 patients. Conclusion: Survival in AL has improved over time, with maximum improvement occurring in the past decade. However, early mortality remains high, and prospective identification of patients at risk of early mortality may allow development of risk-adapted strategies.