BACKGROUND Long-term survival after heart transplantation (HTx) is compromised by cardiac allograft vasculopathy (CAV) characterized by coronary macro- and microvascular disease. The pathogenesis of CAV is unclear and may involve coronary thrombosis. We investigated whether HTx patients with CAV had higher platelet aggregation and turnover than HTx patients without CAV and healthy controls. Furthermore, we investigated the anti-platelet effect of low-dose aspirin in HTx patients. METHODS We included 57 patients who had undergone HTx (median 8.3 years from HTx) and 57 healthy controls. Platelet aggregation was measured on-aspirin and off-aspirin using impedance aggregometry with adenosine diphosphate (ADP) and arachidonic acid (AA). We evaluated platelet turnover by flow cytometry, CAV burden by coronary angiography and echocardiography, and microvascular function by echocardiographic coronary flow velocity reserve (CFVR). RESULTS Off-aspirin, HTx patients with CAV (n = 21) had higher ADP-induced platelet aggregation than healthy controls (p < 0.01) and HTx patients without CAV (n = 36) (p < 0.05). Aspirin treatment reduced AA-induced platelet aggregation in both HTx groups, but HTx patients with CAV had higher platelet aggregation on-aspirin than HTx patients without CAV (p < 0.05). Platelet turnover did not differ between HTx patients with CAV and HTx patients without CAV (p > 0.34). HTx patients with lower CFVR values had higher platelet aggregation than HTx patients with higher CFVR values (p < 0.05). CONCLUSIONS Off-aspirin, platelet aggregation was higher in HTx patients with CAV than in HTx patients without CAV and healthy controls. On-aspirin, platelet aggregation was higher in HTx patients with CAV than in HTx patients without CAV. Aspirin monotherapy may not provide sufficient platelet inhibition in HTx patients with CAV.

中文翻译：

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心脏同种异体血管病的血小板聚集和对阿司匹林治疗的反应。

背景技术心脏移植（HTx）后的长期存活受到以心脏大血管和微血管疾病为特征的心脏同种异体移植血管病（CAV）的损害。CAV的发病机制尚不清楚，可能涉及冠状动脉血栓形成。我们调查了具有CAV的HTx患者是否比没有CAV和健康对照的HTx患者具有更高的血小板凝集和更新率。此外，我们研究了小剂量阿司匹林对HTx患者的抗血小板作用。方法我们纳入了57例接受过HTx治疗的患者（中位距HTx 8.3年）和57例健康对照者。使用二磷酸腺苷（ADP）和花生四烯酸（AA）的阻抗聚集法测定阿司匹林和非阿司匹林的血小板聚集。我们通过流式细胞术评估了血小板更新，通过冠状动脉造影和超声心动图评估了CAV负担，超声心动图冠状动脉血流速度储备（CFVR）监测微血管功能 结果非阿司匹林，HTx合并CAV的患者（n = 21）比健康对照组（p <0.01）和非CAV HTx患者（n = 36）更高的ADP诱导的血小板凝集（p <0.05）。在两个HTx组中，阿司匹林治疗均减少了AA诱导的血小板凝集，但具有CAV的HTx患者的阿斯匹林血小板聚集率高于没有CAV的HTx患者（p <0.05）。有CAV的HTx患者和没有CAV的HTx患者之间的血小板更新率没有差异（p> 0.34）。CFVR值较低的HTx患者的血小板凝集性高于CFVR值较高的HTx患者（p <0.05）。结论带有CAV的HTx患者的非阿司匹林血小板聚集高于没有CAV和健康对照的HTx患者。阿司匹林 患有CAV的HTx患者的血小板聚集高于没有CAV的HTx患者。阿司匹林单一疗法可能不会在CAx的HTx患者中提供足够的血小板抑制作用。