Lymphopenia in the Adult Population With Fontan Physiology: A Potential New Marker for Disease Assessment

• Published in: CJC open (Online) 2024-06, Vol.6 (6), p.773-780
• Main Authors: Scandinaro, Anna L., McCann, Michael D., Chaudhry, Anisa, Kunselman, Allen, Bradley, Elisa A., Davidson, William R.
• Format: Article
• Language: English
• Subjects: Congenital Heart Disease
• ISSN: 2589-790X; 2589-790X
• DOI: 10.1016/j.cjco.2024.01.012

Patients with complex congenital heart disease and Fontan palliation frequently develop extracardiac disease, including hematologic abnormalities, such as lymphopenia. However, the clinical implications of this finding are poorly understood and are therefore the topic of this investigation. Patients with Fontan physiology in our centre (1999-2018) were evaluated for the presence and impact of lymphopenia. The cohort was divided into a group with lymphopenia (L) (2 consecutive absolute lymphocyte counts ≤ 1∗103 K/ μL) and a group who had never had lymphopenia (NL). Clinical characteristics and hospital admissions (762 patient-years) were evaluated. In 62 adult patients with Fontan physiology (aged 34 ± 9 years; 32 women [52%]), the patients who developed lymphopenia earliest did so 8 years after Fontan completion, with up to 60% of patients developing lymphopenia by 30 years. Lymphopenia was found to be associated with portal hypertension (varices, ascites, splenomegaly, and thrombocytopenia [VAST] score)—NL: 0 (0-2) vs L: 2 (0-4), P < 0.0001). A total of 76 heart failure and 81 arrhythmia-associated admissions occurred per 1000 patient-years. At 40 years post-Fontan, the probability of a heart failure admission was higher in the L group (L: 51 [86%] vs NL: 8 [14%], P < 0.01). Adult patients with Fontan physiology and lymphopenia demonstrated portal hypertension and lymphatic dysfunction more commonly, perhaps suggesting that this may be a marker of Fontan congestion and early Fontan failure. Further investigation into the relationship between lymphopenia, clinical outcomes, and Fontan function is needed. Chez les patients atteints d’une cardiopathie congénitale complexe ayant subi une intervention de Fontan, il est fréquent de voir apparaître des maladies extracardiaques, dont des anomalies hématologiques, comme la lymphopénie. Cependant, les implications cliniques de cette observation sont mal comprises et font donc l’objet de cette étude. La présence et l’impact d’une lymphopénie ont été évalués chez des patients présentant une physiologie de Fontan dans notre centre (1999-2018). La cohorte a été divisée en un groupe composé de sujets atteints de lymphopénie (L) (2 mesures consécutives du nombre absolu de lymphocytes ≤ 1 x 103 K/μL) et un groupe de sujets n’ayant jamais présenté de lymphopénie (NL). Les caractéristiques initiales et les hospitalisations (762 années-patients) ont été évaluées. Chez 62 adultes présentant une physiologie de Fontan (âgés de