De Sciscio Michele, De Sciscio Paul, Vallat Wilson, Kleinig Timothy
Neurology & Stroke, Royal Adelaide Hospital, Adelaide, South Australia, Australia.
Biomedical Engineering, Cambridge University, Cambridge, Cambridgeshire, UK.
BMJ Neurol Open. 2021 Jul 13;3(2):e000166. doi: 10.1136/bmjno-2021-000166. eCollection 2021.
Having anecdotally noted a high frequency of lobar-restricted cerebral microbleeds (CMBs) mimicking cerebral amyloid angiopathy (CAA) in patients with previous cardiac surgery (especially valve replacement) presenting to our transient ischaemic attack (TIA) clinic, we set out to objectively determine the frequency and distribution of microbleeds in this population.
We performed a retrospective comparative cohort study in consecutive patients presenting to two TIA clinics with either: (1) previous coronary artery bypass grafting (CABG) (n=41); (2) previous valve replacement (n=41) or (3) probable CAA (n=41), as per the Modified Boston Criteria, without prior cardiac surgery. Microbleed number and distribution was determined and compared.
At least one lobar-restricted microbleed was found in the majority of cardiac surgery patients (65%) and 32/82 (39%) met diagnostic criteria for CAA. Valve replacement patients had a higher microbleed prevalence (90 vs 51%, p<0.01) and lobar-restricted microbleed count (2.6±2.7 vs 1.0±1.4, p<0.01) than post-CABG patients; lobar-restricted microbleed count in both groups was substantially less than in CAA patients (15.5±20.4, p<0.01). In postcardiac surgery patients, subcortical white matter (SWM) microbleeds were proportionally more frequent compared with CAA patients. Receiver operator curve analysis of a 'location-based' ratio (calculated as SWM/SWM+strictly-cortical CMBs), revealed an optimal ratio of 0.45 in distinguishing cardiac surgery-associated microbleeds from CAA (sensitivity 0.56, specificity 0.93, area under the curve 0.71).
Lobar-restricted microbleeds are common in patients with past cardiac surgery, however a higher proportion of these CMBs involve the SWM than in patients with CAA.
在我们短暂性脑缺血发作（TIA）门诊就诊的既往有心脏手术史（尤其是瓣膜置换术）的患者中，我们偶然注意到有较高频率的叶性局限性脑微出血（CMB），类似于脑淀粉样血管病（CAA），因此我们着手客观地确定该人群中微出血的频率和分布情况。
我们对连续就诊于两家TIA门诊的患者进行了一项回顾性比较队列研究，这些患者分为以下三类：（1）既往有冠状动脉旁路移植术（CABG）（n = 41）；（2）既往有瓣膜置换术（n = 41）；或（3）根据改良波士顿标准诊断为可能的CAA（n = 41），且之前无心脏手术史。确定并比较微出血的数量和分布情况。
大多数心脏手术患者（65%）发现至少一处叶性局限性微出血，82例中有32例（39%）符合CAA的诊断标准。瓣膜置换术患者的微出血患病率（90%对51%，p < 0.01）和叶性局限性微出血计数（2.6±2.7对1.0±1.4，p < 0.01）高于冠状动脉旁路移植术后患者；两组的叶性局限性微出血计数均显著低于CAA患者（15.5±20.4，p < 0.01）。在心脏手术后患者中，与CAA患者相比，皮质下白质（SWM）微出血比例更高。对“基于位置”的比率（计算为SWM / SWM +严格皮质CMB）进行受试者操作特征曲线分析，结果显示区分心脏手术相关微出血与CAA的最佳比率为0.45（敏感性0.56，特异性0.93，曲线下面积0.71）。
叶性局限性微出血在既往有心脏手术史的患者中很常见，然而与CAA患者相比，这些CMB累及SWM的比例更高。
