(1) Background: To evaluate the predictive value of Holter monitoring for overall survival (OS) of patients with light chain amyloidosis (AL amyloidosis). (2) Methods: 137 patients with newly diagnosed AL amyloidosis who underwent Holter monitoring within 6 months of diagnosis were included. The primary outcome was OS. Landmark analysis was conducted at one-year follow-up. Independent predictors were determined using the log-rank test and multivariate Cox regression analysis. (3) Results: 131 (95.6%) patients received non-transplant therapy, and 32 (23.4%) underwent daratumumab-based chemotherapy. After a median follow-up of 20.3 months, 47 deaths occurred. Atrial tachycardia (AT), conduction delay, and non-sustained ventricular tachycardia (NSVT) were associated with poor OS one year beyond diagnosis in univariate analyses (patients with vs. without AT: 57.3% [95% confidence interval (CI): 47.2-67.4] vs. 81.0% (95% CI: 74.8-87.2), p = 0.039; patients with vs. without NSVT: 33.3% (95% CI: 8.5-58.1) vs. 75.3% (95% CI: 69.8-80.8), p = 0.024; patients with vs. without conduction delay: 41.7% (95% CI: 24.4-59.0) vs. 75.4% (95% CI: 69.7-81.1), p = 0.003]. AT [hazard ratio (HR): 2.6; 95% CI: 1.0-6.5; p = 0.049) and conduction delay (HR: 4.3; 95% CI: 1.3-14.3; p = 0.016) were independent predictors of OS after accounting for age and 2012 Mayo stage. (4) Conclusion: AT and conduction delay in Holter monitoring are independent predictors of poor OS one year beyond diagnosis in AL amyloidosis.
Keywords: Holter monitoring; atrial tachycardia; conduction delay; prognosis; systemic light chain amyloidosis.