Impact of high titre of antiphospholipid antibodies on postoperative outcome following pulmonary endarterectomy

Objective: Antiphospholipid (a-PL) antibodies, especially IgG isotype, have been associated with a variety of neurological manifestations related to thrombotic mechanism and reactivity against nervous tissues. Furthermore, high titre of a-PL antibodies has been also correlated to chronic thromboembolic pulmonary hypertension (CTEPH) and, therefore, is frequently reported in patients undergoing pulmonary endarterectomy (PEA). The impact of a-PL antibodies in postoperative outcome following PEA, however, has not been clearly evaluated yet. In this paper, we investigated the impact of a high a-PL IgG titre (HAPT) on postoperative outcome following PEA. Methods: From April 1994 to October 2008, out of 204 patients undergoing PEA at our centre, 184 were prospectively screened for a-PL antibodies. According to the preoperative IgG titre, patients were divided into two groups: Group A (high a-PL antibodies titre – HAPT) with a-PL IgG titre >10 U/ml and Group B (low a-PL antibodies titre – LAPT) with a-PL IgG titre ≤10 U/ml. Early outcomes were compared between the two groups. Results: Twenty-eight patients (15%) were included in Group A, whereas 156 (85%) patients were included in Group B. HAPT influenced preoperative parameters as patients of Group A were younger compared to those of Group B (42±16 and 52±16 for Group A and B, respectively, P=0.001) and presented more frequently a previous history of deep venous thrombosis (DVT) (96% and 62% for Group A and B, respectively, P=0.001). The two groups were homogeneous for all other operative parameters. As far as postoperative outcome, in terms of mortality and major complications, there were no differences between the two groups. Incidence of transient neurological complications, however, was significantly different (32% and 10% for Group A and B, respectively, P=0.023). Conclusions: The presence of high titre of IgG isotype a-PL antibodies significantly influences preoperative characteristics of patients undergoing PEA. Furthermore, despite that no significant differences were shown in major end points, the presence of high titre of a-PL did interfere with postoperative course as caused by an increased rate of minor and transient neurological impairment (TNI). An accurate monitoring especially during hypothermic circulatory arrest (CA) period seems, therefore, mandatory in this subgroup of patients undergoing PEA.