Prevalence and prognostic impact of left-sided valve thickening in systemic light-chain amyloidosis

Abstract

Background: Left heart valve thickening (LVT) was described in patients with light-chain amyloidosis (AL). This phenomenon reflects likely infiltration of the valve by amyloid proteins. However, the prevalence of LVT and its prognostic value have not been investigated in patients with AL.

Methods and results: Comprehensive transthoracic echocardiography was performed at baseline in 150 patients [median age 68 (33-87) years; 59% male] with confirmed AL. The presence of abnormal mitral and/or aortic valve thickening (>3 mm) was assessed in all included patients. Overall, 42% had LVT at the time of diagnosis. Compared to patients without LVT, those with LVT were older and had a more advanced NYHA functional class (63% in patients with NYHA III-IV vs. 33% in NYHA I-II, p < 0.001). They also had higher left ventricular (LV) wall thickness and mass, larger left atrium, higher mitral annulus E/E' ratio and systolic pulmonary artery pressures, and lower LV ejection fraction (all p < 0.05). Patients with more advanced Mayo Clinic stage had a higher incidence of LVT: 58% in stage III vs. 45% in stage II and 5% in stage I (p < 0.001). During a median follow-up of 2 years, 79 deaths occurred. The presence of LVT was significantly associated with reduced 5-year survival (32 ± 7 vs. 64 ± 6%). In multivariate analysis, after adjusting for age, gender, NYHA functional class, and LV ejection fraction, LVT remained significantly associated with higher all-cause mortality (hazard ratio 1.90, 95% CI 1.10-3.34, p = 0.02).

Conclusion: Left heart valve thickening is common in patients with AL and is associated with worse functional class, LV systolic and diastolic function, and more advanced stage of the disease. In addition, LVT appears to be a powerful marker of all-cause mortality.

Keywords: Amyloidosis; Echocardiography; Light chains; Prognosis; Survival; Valve.