Impact of Cardiac Disease on Prognosis in Patients with Systemic AL Amyloidosis

Abstract

AIM. To assess the clinical features as well as the factors affecting prognosis and long-term treatment outcomes in systemic AL amyloidosis patients with cardiac involvement.

MATERIALS & METHODS. The trial enrolled 123 systemic AL amyloidosis patients with cardiac involvement who were treated at the RM Gorbacheva Scientific Research Institute in 2004–2023. The patients were 34–85 years of age (median 61 years); there were 61 women (49.6 %) and 62 men (50.4 %).

RESULTS. Cardiac disease grades 1, 2, 3a, and 3b were identified in 13.8 %, 50.4 %, 17.9 %, and 17.9 % of AL amyloidosis patients, respectively. Chronic cardiac failure (CCF) developed in 65.9 % (n = 81), and severe cardiac failure was detected in 25.4 % (n = 31) of patients. Most of them (90,2 %), despite CCF, preserved left ventricular ejection fraction (> 40 %) with the mean value of 59.6 % (range 33–78 %). The left ventricular stroke volume index (SVI) was below the normal values (< 41 mL/m²) in 92.7 % of patients. The mean SVI value was 26.1 mL/m² (range 8.3–49.5 mL/m²). The lower SVI was associated with cardiac disease grades. This parameter appeared to be 30.9 mL/m², 26.8 mL/m², 24.8 mL/m², and 21.4 mL/m² in grades 1, 2, 3a, and 3b (p = 0.006), respectively. Total global strain (TGS) in the left ventricle myocardium was decreased (< 20 %) in 94.6 % of patients. The mean TGS value was 13.8 % (range 4.4–34.8 %). TGS was diminishing with increasing cardiac disease grade (grade 1 with 17.8 %, grade 2 with 14.6 %, grade 3a with 13.1 %, and grade 3b with 9.6 %) (p = 0.007). Atrial fibrillation was reported in 23 % of patients, supraventricular tachycardia was observed in 31.9 %, and supraventricular extrasystoles were registered in 39.7 %. Ventricular extrasystoles were found in 73.7 % of patients, and ventricular tachycardia was seen in 13.2 %. Sinoatrial block was reported in 6.6 % of patients, and atrioventricular block was identified in 19.8 %. Syncope occurred in 12.3 % of patients. An artificial cardiac pacemaker was implanted in 8 patients. The thromboembolism rate was 13 %: the myocardial infarction rate was 11.4 %, and the rate of acute cerebrovascular accidents was 5.7 %. Atrial clots were detected in 2 (1.6 %) patients. The cumulative incidence of hematologic response for 2 years was 57 % and did not depend on cardiac disease grade, the 2-year rate of cardiac response was 39.1 %. Before achieving hematologic and cardiac responses, mortality was 26.5 % and 29.9 %, respectively. The overall 5-year survival was 62.6 %, and the 5-year hematologic progression-free and major organ impairment-free survival was 39.3 %. Cox regression model confirmed 3 independent predictors of poor prognosis: the level of NT-proBNP ≥ 2500 pg/mL (p = 0.004), SVI < 25 mL/m² (p = 0.0174), and prior syncope (p = 0.0191). The achievement of hematologic response had a positive effect on survival rates (p < 0.0001).

CONCLUSION. A comprehensive assessment of cardiac damage by the time of primary AL amyloidosis diagnosis as well as appropriate treatment of this disease can reduce the risk of early cardiac mortality and enhance chances of not only achieving hematologic response but also improving survival rates.