White Blood Cell Count Is Associated With Hospitalisation for Heart Failure in Patients With ATTR Cardiac Amyloidosis

AIMS AND BACKGROUND: Transthyretin amyloid cardiomyopathy (ATTR-CM) is the most common form of cardiac amyloidosis leading to restrictive cardiomyopathy and progressive heart failure. The prognostic relevance of inflammatory biomarkers is unknown so far. This study aims to evaluate an association of white blood cell (WBC) count and clinical outcome in form of hospitalisation for heart failure in ATTR-CM patients. METHODS AND RESULTS: WBC count was assessed in 150 patients (median age 80 [76-82] years; 13.3% female) with ATTR-CM from the West German Amyloidosis Center. Most patients (95.3%) received transthyretin stabilizer therapy. The cohort was divided into patients with low and high WBC count by median split. Hospitalisation for heart failure was defined as primary endpoint. The median follow-up time was 825 (728-932) days. ATTR-CM patients with high WBC count showed higher prevalence of heart failure with reduced ejection fraction (HFrEF) at baseline assessment. High WBC count was mainly driven by a relative increase in neutrophils. During follow-up incidence of hospitalisation for heart failure was higher in patients with high WBC count (log-rank p = 0.035). Cox regression confirmed an association between WBC count and occurrence of hospitalisation due to heart failure (hazard ratio [HR]: 1.130; 95% confidence interval [CI]: 1.015-1.257; p = 0.025), which was unaffected after adjustment for further confounders. CONCLUSIONS: Increased WBC count was associated with incidence of hospitalisation for heart failure in ATTR-CM patients, indicating a potential for inflammatory biomarkers in disease monitoring.