Fondazione Arianna Anticoagulazione, Bologna, Italy.
Centro Emostasi e Trombosi, Laboratorio Analisi Chimico-Cliniche e Microbiologiche, ASST Cremona, Cremona, Italy.
Int J Cardiol. 2024 Dec 1;416:132484. doi: 10.1016/j.ijcard.2024.132484. Epub 2024 Aug 24.
The MAS study (Blood Advances 2024) showed that a high proportion of Italian AF patients treated with direct oral anticoagulants (DOACs) receive reduced doses. This sub-analysis of MAS data aimed to analyze the effects of reduced (appropriate or not)- or standard-dose use on DOAC activity assessed at baseline and the occurrence of thrombotic or bleeding complications during follow-up.
The MAS study design, the methods for DOAC measurement, the results, and the adverse events during follow-up, are described in detail elsewhere.
Seven hundred AF patients (42 % of the total 1657) received a reduced dose (considered inappropriate in 140 [20 %]). They were older, more frequently women, with lower body mass index (BMI), hemoglobin levels, and creatinine clearance. They more often had cerebral or cardiovascular diseases, were taking more medications, with higher scores for thrombotic or bleeding risk. Despite the use of low doses, 133 (19.0 %) patients had high standardized C-trough DOAC levels and experienced a high proportion of bleeding events (8.3 % per year). Conversely, some patients (4.7 %) had very low levels, resulting in a high incidence of thrombotic events (6.7 % per year). No difference was detected if the reduced dose was appropriate or not.
The unpredictable, highly variable inter-individual anticoagulant effect of DOACs may lead to either too low or too high anticoagulant levels, increasing the risk of thrombotic or bleeding events. This is particularly relevant for patients with high-risk conditions, such as those chosen for reduced-dose treatment. Further studies are needed to investigate this important clinical issue.
MAS 研究（Blood Advances 2024）表明，接受直接口服抗凝剂（DOAC）治疗的意大利 AF 患者中有很大一部分接受了降低剂量。对 MAS 数据的这项亚分析旨在分析在基线时评估 DOAC 活性以及在随访期间发生血栓或出血并发症时，使用降低（合适或不合适）剂量或标准剂量对 DOAC 活性的影响。
MAS 研究设计、DOAC 测量方法、结果以及随访期间的不良事件，详见其他地方的描述。
700 例 AF 患者（占 1657 例的 42%）接受了降低剂量（其中 140 例[20%]被认为不合适）。他们年龄更大，更频繁地为女性，体重指数（BMI）、血红蛋白水平和肌酐清除率更低。他们更常患有脑或心血管疾病，服用更多药物，血栓形成或出血风险评分更高。尽管使用了低剂量，但 133 例（19.0%）患者的 DOAC 标准化 C 低谷水平较高，出血事件发生率较高（每年 8.3%）。相反，一些患者（4.7%）的 DOAC 水平非常低，导致血栓事件发生率很高（每年 6.7%）。剂量降低合适与否均未检测到差异。
DOAC 个体间抗凝效果不可预测且高度可变，可能导致抗凝水平过低或过高，增加血栓形成或出血事件的风险。对于高危患者，如选择接受降低剂量治疗的患者，这一点尤为重要。需要进一步研究来探讨这一重要的临床问题。
