Prognostic Significance of Holter Monitor Findings in Patients With Light Chain Amyloidosis

Abstract

ObjectiveTo evaluate the prognostic impact of Holter findings in patients with light chain amyloidosis. Patients and MethodsWe evaluated 239 patients in whom light chain amyloidosis was diagnosed from January 1, 2010, through December 31, 2015, who underwent 24-hour Holter monitoring. ResultsHolter testing was done before stem cell transplant evaluation in 183 of the 239 patients (76.6%) and at diagnosis in 50 (20.9%). Holter findings were nonsustained ventricular tachycardia (NSVT) in 60 patients (25.1%), ventricular couplets in 103 (43.1)%, accelerated idioventricular rhythm in 32 (13.4%), and atrial fibrillation (AF) in 18 (7.5%). Overall survival (OS) at 3 and 6 months after Holter monitoring in patients with AF vs without AF was 78% (95% CI, 54%-91%) vs 96% (95% CI, 92%-98%) (P=.002) and 61% (95% CI, 38%-80%) vs 92% (95% CI, 87%-95%), (P<.001), respectively. In patients with and without NSVT, 3- and 6-month OS after Holter testing was 90% (95% CI, 80%-94%) vs 96% (95% CI, 91%-98%) (P=.12) and 77% (95% CI, 64%-85%) vs 94% (95% CI, 89%-97%) (P<.001), respectively. For patients with and without ventricular couplets, 3- and 6-month OS was 94% (95% CI, 88%-97%) vs 94% (95% CI, 89%-97%) (P=.98) and 84% (95% CI, 75%-89%) vs 94% (95% CI, 89%-97%) (P=.01), respectively. Atrial fibrillation (hazard ratio, 2.5; 95% CI, 1.2-5.0; P=.02) and NSVT (hazard ratio, 2.0; 95% CI, 1.1-3.5; P=.02) were independent predictors for OS after accounting for age and Mayo stage. For patients undergoing routine testing before stem cell transplant, AF (P=.002) and NSVT (P=.02) were associated with inferior OS at 6 months but did not retain statistical significance after adjusting for Mayo stage (P=.10 and P=.54, respectively). ConclusionAtrial fibrillation and NSVT on 24-hour Holter monitoring are associated with inferior short-term OS outcomes but do not impact peritransplant mortality.