Abstract：
BACKGROUND: The pathophysiology of Takotsubo syndrome (TTS) remains incompletely understood. While coronary microvascular dysfunction (CMD) is a potential pathophysiologic mechanism, evidence is limited.
OBJECTIVE: We sought to evaluate CMD in patients with TTS.
METHODS: Consecutive patients diagnosed with TTS were included and underwent coronary angiography with invasive microvascular function evaluation, including fractional flow reserve, Coronary Flow Reserve (CFR), Index of Microcirculatory Resistance (IMR), and Resistive Reserve Ratio (RRR). Patients had an echocardiography evaluation during their index admission and at approximately 6 weeks.
RESULTS: Thirty patients were included (mean age 74 ±9, 90 % female). Twenty-five patients (83 %) had at least one abnormal coronary microvascular function parameter. Abnormal parameters included CFR<2.5 in 20 patients (67 %), IMR>25 in 18 patients (60 %), and RRR<3.5 in 25 (83 %). Longer time from symptoms to angiography correlated with a higher CFR (r = 0.51, P<0.01), and had an area under the receiver operating characteristic curve of 0.793 (95 % CI 0.60-0.98) for pathologic CFR. Patients with emotional trigger had a lower rate of pathologic IMR compared with non-emotional trigger (36 % vs 81 %, p = 0.01). Follow up echocardiography performed at a median of 1.5 months (IQR 1.15-6) showed an improvement in left ventricular ejection fraction for all patients (from mean of 40 % to 57 %).
CONCLUSIONS: CMD was present in most patients with TTS. The role of microvascular function in TTS may vary according to the clinical presentation and RRR may be more sensitive for the diagnosis of CMD in TTS.
OBJECTIVE: We sought to evaluate CMD in patients with TTS.
METHODS: Consecutive patients diagnosed with TTS were included and underwent coronary angiography with invasive microvascular function evaluation, including fractional flow reserve, Coronary Flow Reserve (CFR), Index of Microcirculatory Resistance (IMR), and Resistive Reserve Ratio (RRR). Patients had an echocardiography evaluation during their index admission and at approximately 6 weeks.
RESULTS: Thirty patients were included (mean age 74 ±9, 90 % female). Twenty-five patients (83 %) had at least one abnormal coronary microvascular function parameter. Abnormal parameters included CFR<2.5 in 20 patients (67 %), IMR>25 in 18 patients (60 %), and RRR<3.5 in 25 (83 %). Longer time from symptoms to angiography correlated with a higher CFR (r = 0.51, P<0.01), and had an area under the receiver operating characteristic curve of 0.793 (95 % CI 0.60-0.98) for pathologic CFR. Patients with emotional trigger had a lower rate of pathologic IMR compared with non-emotional trigger (36 % vs 81 %, p = 0.01). Follow up echocardiography performed at a median of 1.5 months (IQR 1.15-6) showed an improvement in left ventricular ejection fraction for all patients (from mean of 40 % to 57 %).
CONCLUSIONS: CMD was present in most patients with TTS. The role of microvascular function in TTS may vary according to the clinical presentation and RRR may be more sensitive for the diagnosis of CMD in TTS.
摘要：
背景：Takotsubo综合征（TTS）的病理生理学仍未完全了解。冠状动脉微血管功能障碍（CMD）是一种潜在的病理生理机制，证据有限。
目的：我们试图评估TTS患者的CMD。
方法：连续纳入诊断为TTS的患者，行冠状动脉造影并进行有创微血管功能评估，包括血流储备分数,冠状动脉血流储备(CFR),微循环阻力指数(IMR)和电阻储备率(RRR)。患者在入院期间和大约6周时进行了超声心动图评估。
结果：纳入30例患者（平均年龄74±9岁，90%为女性）。25例患者（83％）至少有一个异常的冠状动脉微血管功能参数。异常参数包括20例患者的CFR<2.5（67%），18例患者（60%）IMR>25，25％的RRR<3.5（83％）。从症状到血管造影的时间越长，CFR越高（r=0.51，P<0.01）。病理性CFR的受试者工作特征曲线下面积为0.793(95%CI0.60-0.98)。与非情绪触发相比，有情绪触发的患者的病理性IMR发生率较低（36％vs81％，p=0.01)。中位时间为1.5个月（IQR1.15-6）的随访超声心动图显示，所有患者的左心室射血分数均有改善（平均值为40％至57％）。
结论：CMD存在于大多数TTS患者中。微血管功能在TTS中的作用可能因临床表现而异，RRR可能对TTS中CMD的诊断更敏感。
目的：我们试图评估TTS患者的CMD。
方法：连续纳入诊断为TTS的患者，行冠状动脉造影并进行有创微血管功能评估，包括血流储备分数,冠状动脉血流储备(CFR),微循环阻力指数(IMR)和电阻储备率(RRR)。患者在入院期间和大约6周时进行了超声心动图评估。
结果：纳入30例患者（平均年龄74±9岁，90%为女性）。25例患者（83％）至少有一个异常的冠状动脉微血管功能参数。异常参数包括20例患者的CFR<2.5（67%），18例患者（60%）IMR>25，25％的RRR<3.5（83％）。从症状到血管造影的时间越长，CFR越高（r=0.51，P<0.01）。病理性CFR的受试者工作特征曲线下面积为0.793(95%CI0.60-0.98)。与非情绪触发相比，有情绪触发的患者的病理性IMR发生率较低（36％vs81％，p=0.01)。中位时间为1.5个月（IQR1.15-6）的随访超声心动图显示，所有患者的左心室射血分数均有改善（平均值为40％至57％）。
结论：CMD存在于大多数TTS患者中。微血管功能在TTS中的作用可能因临床表现而异，RRR可能对TTS中CMD的诊断更敏感。
