Chronic Thromboembolic Pulmonary Hypertension With Cold Agglutinins Needing Pulmonary Thromboendarterectomy: The Use of Therapeutic Plasma Exchange

ABSTRACT

Cold agglutinins can be detected in patients with chronic thromboembolic pulmonary hypertension (CTEPH) during pulmonary thromboendarterectomy (PTE) pre‐operative testing. Peri‐operative management of these patients in anticipation of deep hypothermic circulatory arrest can be challenging and has not been standardized. We describe our relevant experience and suggest a potential protocolized pre‐operative approach with this observational, retrospective cohort study. A chart review of all patients undergoing PTE surgery for CTEPH (1107 patients) at UC San Diego between 2019 and 2025 was performed. An Institutional Review Board approved quality improvement database on all patients undergoing PTE surgery was used. Twenty‐one patients (1.9%) screened positive for cold agglutinins pre‐PTE. A high co‐prevalence of antiphospholipid syndrome and cold agglutinins was noted (17/21; 81%). Thermal amplitude testing (when possible) was positive for nine patients between 15°C and 18°C. Fifteen patients underwent therapeutic plasma exchange (median of two sessions) with albumin and plasma replacement fluid followed by PTE surgery with standard cooling protocol. There were no incidents of agglutination or hemolysis peri‐ or post‐operatively. Three patients had post‐operative airway hemorrhage, two of which developed heparin‐induced thrombocytopenia (HIT). There was one mortality in the setting of HIT with recurrent thrombosis and bleeding. Median intensive care unit and hospital length of stays were 3 and 12.5 days, respectively. We suggest a protocolized approach for the identification and management of high‐risk patients with cold agglutinins, which may include therapeutic plasma exchange pre‐operatively. This can successfully mitigate the potential risk of hypothermic circulatory arrest causing agglutination during surgery.