Coronary angiographic manifestations of fibromuscular dysplasia and clinical outcomes in patients with spontaneous coronary artery dissection

Background Fibromuscular dysplasia (FMD) is a common predisposing condition for spontaneous coronary artery dissection (SCAD), which is an important cause of myocardial infarction (MI) in young to middle-aged women. However, its impact on clinical presentation, coronary anatomies, and outcomes have not been reported. Purpose To evaluate coronary angiographic characteristics and clinical outcomes in SCAD patients with or without underlying extracoronary FMD. Methods We retrospectively analyzed patients enrolled in our Vancouver SCAD registries who were screened for extracoronary FMD. Extracoronary FMD was defined as the presence of multifocal FMD on catheter or noninvasive angiography (computed tomographic or magnetic resonance imaging) in ≥1 extracoronary vascular beds. We reviewed coronary angiograms for manifestations of coronary FMD that were previously described (i.e. irregular stenosis, smooth stenosis, dilatation/ectasia, and tortuosity). Severe tortuosity was defined as ≥2 consecutive bends ≥180° at any cardiac cycle or 360° loop in ≥1 epicardial artery that was ≥2 mm in diameter. Clinical outcomes of major adverse cardiovascular event (MACE), a composite of all-cause death, MI, and stroke, were evaluated. Results We included 346 SCAD patients, 250 (72.3%) had extracoronary FMD. Patients with FMD were older (54.6±9.5 vs. 51.7±9.8 years) and more likely to have prior history of MI (7.2% vs. 1.0%, p=0.047) and stroke (4.4% vs. 0%, p=0.081) compared with non-FMD patients. The proportion of multivessel SCAD and TIMI flow was not different between groups, but type 3 SCAD was more commonly observed in FMD group (11.6% vs. 3.1%, p=0.026). On coronary angiography, severe tortuosity was more prevalent in patients with extracoronary FMD (58.4% vs. 36.5%, p<0.001), whereas rates of irregular stenosis, smooth stenosis, and dilatation/ectasia were not significantly different (Figure). Percutaneous coronary intervention was performed in 13.2% of FMD and 15.6% of non-FMD group, with similar success rates (75.8% vs. 69.2%, p=0.65). In-hospital and long-term MACE rate at median follow-up of 1032 (IQR 453–1096) days were not different between FMD and non-FMD groups (in-hospital: 5.6% vs. 8.3%, p=0.492; long-term: 19.6% vs. 15.6%, p=0.185). Conclusion In SCAD patients, severe coronary tortuosity was more prevalent in patients with FMD than those without. Despite the complex coronary anatomy, FMD was not associated with worse outcomes. Differences in coronary manifestations Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): Canadian Institutes of Health Research

Spontaneous Mirror Dissections of Cervicocephalic Arteries

While so-called twin or mirror aneurysms constitute an established subgroup of multiple aneurysms, simultaneous spontaneous mirror dissections of cervicocephalic artery have not yet been reported as a particular entity. Among the patients treated at our institution since 1989, we identified 74 patients with spontaneous, non-traumatic dissections. Six of these cases presented with simultaneous bilateral dissections and four of the six patients had mirror dissections. Acute or chronic headache was present in all four cases. Additional clinical presentations consisted of impaired consciousness, cranial nerve palsy, and tinnitus. Angiography revealed irregular stenosis, dilatation or aneurysms located in the cervical ICA (internal carotid artery), VA (vertebral artery), or MCA (middle cerebral artery) without evident location bias. Although mirror dissections seems to be an exceptional finding, they may shed light on the vulnerability of different arterial segments to specific diseases. Similar to arterial aneurysm formation, pathogenesis of mirror dissection may involve an underlying “shared defect” in the endothelial cells, since these cells demonstrate a bilateral distribution during embryological development. This particular distribution therefore also provides a chronicle trail of the first trigger striking during embryonic development and demonstrates the segmental vulnerability to highly specific triggers.

Morphological Change of Unruptured Vertebral Artery Dissection on Serial MR Examinations

Basi-parallel anatomical scanning (BPAS)-MRI is a simple MRI technique to reveal the surface contour of the intracranial vertebrobasilar artery. The purpose of this study was to investigate the usefulness of BPAS-MRI for observing the temporal course of unruptured vertebral artery (VA) dissection in patients by means of serial MR examinations. Since April 2003, we performed serial MR examinations in four patients with unruptured acute vertebral artery dissection. The frequency of the MR examinations during the follow-up period in each patient varied from twice within seven months to five times within 19 months. Both MRA and BPAS-MRI were obtained in each MR examination. We investigated the course of morphological changes within the dissected artery on BPAS-MRI (outer contour) and on MRA (inner lumen). Although the initial MRA showed fusiform dilatation, irregular stenosis or normal caliber at the dissected lesion, the initial BPAS-MRI disclosed fusiform dilatation in all of the four patients. In two patients, MRA finding of the VA lesion had changed, though the fusiform appearance had been stationary on BPAS-MRI. Then both dissolution of the fusiform dilatation on BPAS-MRI and normalization of the inner luminal caliber on MRA were confirmed within nine months. In one patient, fusiform dilatation on both BPAS-MRI and MRA resolved simultaneously on the MR examination at eight months after the initial symptom. In another patient, fusiform dilatation of the outer contour was still enlarging on BPAS-MRI ten months after the onset, though the fusiform dilatation on MRA had been stationary since the eighth week. We performed endovascular coil embolization in this patient eleven months after the initial symptom. Resolution of the fusiform dilatation on BPAS-MRI should be a healing sign of VA dissection. Persisting the fusiform dilatation or progressively enlarging outer contour on BPAS-MRI may be an unstable sign. BPAS-MRI provides more information about the instability of the dissected lesion. We should obtain not only MRA but also BPAS-MRI for the course observation of unruptured VA dissection.

Pulsatile tinnitus as a symptom of cervicocephalic arterial dissection

The aim of this study was to investigate pulsatile tinnitus as a presenting symptom in cervicocephalic arterial dissection (CCAD). Of the 136 consecutive patients with confirmed CCAD, 16 presented with pulsatile tinnitus. On admission 10 patients presented with subjective tinnitus and five with objective tinnitus, tinnitus being the only presenting symptom in one case. In one further case with bilateral ICA dissection (ICAD) subjective tinnitus appeared three months after the initial symptoms of arterial dissection, despite a contralateral cervical bruit being evident on admission. Thirteen patients presented with headache or neck pain. Ischaemic symptoms were detected in six and Horner’s syndrome in four patients. Vertigo and dysgeusia were reported in two patients each. Arterial dissection involved unilateral ICA in 11, bilateral ICA in two, unilateral vertebral artery (VA) in two and bilateral ICA and bilateral VA in one patient. In angiography the most common finding was irregular stenosis, and the majority of these abnormalities normalized during follow-up. To avoid delay in diagnosis a high index of suspicion and early angiography (digital subtraction or magnetic resonance angiography) are warranted.

Spontaneous Mirror Dissections of Cervicocephalic Arteries

While so-called twin or mirror aneurysms constitute an established subgroup of multiple aneurysms, simultaneous spontaneous mirror dissections of cervicocephalic artery have not yet been reported as a particular entity. Among the patients treated at our institution since 1989, we identified 74 patients with spontaneous, non-traumatic dissections. Six of these cases presented with simultaneous bilateral dissections and four of the six patients had mirror dissections. Acute or chronic headache was present in all four cases. Additional clinical presentations consisted of impaired consciousness, cranial nerve palsy, and tinnitus. Angiography revealed irregular stenosis, dilatation or aneurysms located in the cervical ICA (internal carotid artery), VA (vertebral artery), or MCA (middle cerebral artery) without evident location bias. Although mirror dissections seems to be an exceptional finding, they may shed light on the vulnerability of different arterial segments to specific diseases. Similar to arterial aneurysm formation, pathogenesis of mirror dissection may involve an underlying “shared defect” in the endothelial cells, since these cells demonstrate a bilateral distribution during embryological development. This particular distribution therefore also provides a chronicle trail of the first trigger striking during embryonic development and demonstrates the segmental vulnerability to highly specific triggers.