Impact of computed tomography on the diagnosis of Takayasu arteritis with acute coronary syndrome: A case series

Abstract

Both the diagnosis and treatment of coronary artery involvement with Takayasu arteritis (TA) are challenging. In this study, we report different clinical scenarios of two TA cases without Typical symptoms of TA that initially presented in the form of acute coronary syndrome (ACS). Patient 1 was a 24-year-old Japanese woman without coronary risk factors who presented with exertional chest pain, dyspnea, and syncope. Invasive coronary angiography (ICA) revealed a considerable lesion of the right coronary artery and the left main trunk. Ventricular fibrillation was observed immediately after the procedure. Despite conventional treatment, she died on day 16. Patient 2 was a 34-year-old Japanese woman without coronary risk factors who developed cardiogenic shock during a treadmill test for exertional chest pain. Coronary computed tomography angiography confirmed severe left main stenosis, presenting as ACS caused by TA. She was started on steroid therapy before coronary artery bypass grafting, resulting in a good postoperative course and no recurrence of chest pain. Therefore, coronary computed tomography angiography likely is useful for the early diagnosis of TA in young women with typical chest symptoms of ACS. It may help in avoiding complications associated with ICA.

Learning objective

When young women with a low pre-test probability of coronary artery disease present with typical anginal symptoms, Takayasu arteritis (TA) should be suspected despite the absence of symptoms such as fever, fatigue, or myalgia. Coronary computed tomography angiography is safe for rapid diagnosis and decision-making when patients suspected of having TA initially manifest an unstable condition such as acute coronary syndrome.

Introduction

Takayasu arteritis (TA) is a rare chronic inflammatory disease of unknown etiology [1], wherein the inflammation primarily affects the aorta and its major branches but may occasionally involve the coronary artery. In TA with coronary artery involvement, acute coronary syndrome (ACS) is the first manifestation, which can potentially result in a misdiagnosis and relatively high mortality. Therefore, an immediate and accurate diagnosis and prompt treatment are essential for improving the outcomes of this condition. Herein, we present two cases of TA with ACS as the initial manifestation, both of which had different outcomes.

Case report

Patient 1

A 24-year-old Japanese woman presented to our hospital (Toho University Omori Medical Center, Tokyo, Japan) with exertional chest pain, dyspnea, and syncope for a few months. No symptoms of fever, fatigue, or myalgia were observed. No disease and family history of sudden cardiac death (SCD) were noted. Her symptoms were stable upon hospitalization. She was afebrile, with a blood pressure of 101/87 mm Hg in the right arm; blood pressure was not measured in the left arm. Heart sounds were normal and without murmurs. Electrocardiography (ECG) revealed sinus rhythm and horizontal ST depression in the II, III, aVF, and V2–6 leads (Fig. 1a). Chest radiography and echocardiography showed no abnormal findings. C-reactive protein (CRP) level was elevated at 2.3 mg/dL (normal range: 0–0.2 mg/dL), whereas the white blood cell (WBC) count, creatine kinase (CK), CK-MB, and troponin-I levels were normal. Coronary artery stenosis by coronary spastic angina or any arteritis was suspected owing to abnormal changes in the ECG despite the low pre-test probability (PTP) of coronary artery disease (CAD). Only one of the American College of Rheumatology (ACR) criteria for TA was met for this patient [1]. On day 2, elevated troponin-I level was noted at 0.62 ng/mL (normal range: <0.014 ng/mL). Invasive coronary angiography (ICA) revealed 99% stenosis in the ostium of the right coronary artery (RCA) and left main trunk (LMT) (Fig. 1b, c; Online data), which resulted in ventricular fibrillation. After defibrillation, extracorporeal membrane oxygenation (ECMO) and intra-aortic balloon pumping were initiated owing to pulseless electrical activity and severe pulmonary edema. Intravascular ultrasound revealed extravascular fibrous structures that were found to be compressing the LMT (Fig. 1d). Emergent percutaneous coronary intervention (PCI) was performed on both ostial stenoses of the RCA and LMT. A drug-eluting stent was implanted in both the lesions. After PCI, non-ECG-gated, non-contrast chest computed tomography (CT) showed a 10.8-mm thickening of the ascending aorta (Fig. 1e). Coronary artery stenosis was additionally identified since admission, but the diagnostic criteria for TA were not met. TA was however suspected based on the thickening of the aortic wall, and further examinations were performed. Erythrocyte sedimentation rate (ESR) showed elevation, and the patient was HLA-B52-positive. Possibilities of other vasculitis syndromes were ruled out by physical examination and age. A final diagnosis of TA was made because she had no other organ disease and was HLA-B52-positive. ECMO could not be discontinued for the patient because of the severe pulmonary edema. She subsequently developed pneumonia, which eventually led to sepsis. The infection could not be controlled, and she died on day 16.

Fig. 1.

Findings of patient 1. (a) Electrocardiography (ECG) at admission revealed sinus rhythm and horizontal ST depression in the II, III, aVF, and V2–6 leads. There were no subjective symptoms, including chest pain or palpitations, during ECG recording. Coronary angiography images show (b) right coronary artery ostium stenosis (red arrows) and (c) left coronary artery ostium stenosis (red arrows). (d) Intravascular ultrasound shows the presence of circumferential fibrous structures outside the vessel. (e) A non-ECG-gated, non-contrast computed tomography (CT) after ventricular fibrillation image demonstrates thickening of the aortic wall (yellow arrows).

Patient 2

A 34-year-old Japanese woman presented to a different hospital with exertional chest pain and dyspnea for the past few months. After a treadmill test, she was referred to our hospital because of cardiogenic shock, which showed horizontal ST depression in I, II, III, aVL, aVF, V3–6 leads and ST elevation in aVR (Fig. 2a). The treadmill test was stopped at the previous hospital for her to rest, after which her vital signs gradually recovered. On arrival at our hospital, her condition and vitals were stable. She had no disease and family history of SCD. She was found to be afebrile, and her brachial systolic blood pressure was higher in the left arm than in the right arm (90 mm Hg vs. 70 mm Hg). A diminished pulse was noted in the right radial artery. Heart sounds were normal and without murmurs. ECG revealed sinus rhythm and ST depression in the I, aVL, and V3–6 leads (Fig. 2b). Chest radiography and echocardiography showed no abnormal findings. Elevated levels of CRP and WBC were observed at 8.6 mg/dL and 9100/μL (normal range: 3300–8600/μL), respectively. Although the CK, CK-MB, and troponin-I levels were normal at arrival, a repeat assessment of troponin-I a few hours later showed its level to have increased (0.12 ng/mL). Three of the ACR diagnostic criteria for TA were positive, and TA was strongly suspected. Because of our experience with patient 1, coronary computed tomography angiography (CTA) was first performed to evaluate the ostium of the coronary arteries and the thickness of the aortic wall. Coronary CTA demonstrated severe stenosis in the ostium of the LMT and moderate stenosis in the ostium of the RCA (Fig. 2c–e). Circumferential thickening of the ascending aortic wall was noted on contrast and non-contrast CT (Fig. 3a, b). Moreover, coronary CTA confirmed stenosis of the bilateral common carotid arteries and the right subclavian artery (Fig. 2f). Because of the life-threatening shock secondary to new-onset atrial fibrillation and the ongoing severe myocardial ischemia during clinical assessment, prednisolone (PSL) 50 mg/day (1 mg/kg/day) was immediately administered and emergency coronary artery bypass grafting (CABG) was performed without conducting an ICA. Although the great saphenous vein was selected as the bypass graft, it could not be used because of laser treatment for cosmetic purpose in the past. Examining the artery that could be used for the graft was not possible because of the emergency surgery. However, given the findings of intact internal thoracic arteries on coronary CTA, the left internal thoracic artery was selected as the bypass graft for the left anterior descending artery. After surgery, the patient had no complications, including infection, and the chest pain disappeared. The double ring sign, a typical TA finding, was observed in the delayed-phase CTA after surgery (Fig. 3c). Furthermore, HLA-B52 was positive and IgG4 levels were normal; therefore, a diagnosis of TA was made. Possibilities of other arteritis diseases were ruled out based on physical examination and age. The PSL dose was reduced by 5 mg/day every week from 2 weeks after the initial administration. Since the time when the PSL dose was reduced to 30 mg/day, tocilizumab at 162 mg was subcutaneously administered every week. Although the coronary CTA on day 32 showed no change in stenosis in the coronary artery ostium, there was a considerable reduction in the ascending aortic wall thickening (Fig. 3d). The inflammation was considered to be under control because no increase in the CRP and ESR levels was observed at the same time. On day 47, she was discharged with her PSL dose reduced to 17 mg/day.

Fig. 2.

Findings of patient 2. (a) Electrocardiography (ECG) after a treadmill test showed horizontal ST depression in the I, II, III, aVL, aVF, V3–6 leads and ST elevation in aVR. ST changes returned spontaneously with rest. (b) ECG at admission revealed sinus rhythm and slight ST depression in the I, aVL, and V3–6 leads. Coronary computed tomography angiography (CTA) images at admission show (c, d) severe stenosis in the left main trunk (white arrows) and (e) mild stenosis in the ostium of the right coronary artery. (f) The three-dimensional reconstruction from coronary CTA shows slight stenosis of the bilateral common carotid arteries (yellow arrows). The right subclavian artery shows an abnormal origin and severe stenosis (red arrows). They are consistent with the absence of bruits in the bilateral common carotid arteries and the presence of blood pressure differences in the brachial arteries.

Fig. 3.

Thickening of the aortic wall in patient 2. Computed tomography (CT) at admission (a) without contrast and (b) with contrast shows thickening of the aortic wall (yellow arrows). (c) After surgery, delayed-phase contrast-enhanced CT shows a double ring sign (white arrows). (d) Contrast-enhanced CT at discharge (40 days after the start of steroid therapy) shows improvement in the thickening of the aortic wall (red arrow). However, the stenoses of the right and left coronary ostia, bilateral common carotid arteries, and right subclavian artery show no changes.

Discussion

We report two cases of TA that presented as ACS but had different clinical courses. Coronary artery involvement was observed in approximately 10%–30% of patients with TA, with 87.5% of the coronary artery lesions leading to hemodynamically significant CAD in the coronary ostium [2] and high mortality [3]. As shown in the cases in this present report, chest symptoms can be isolated signs of TA, without the typical clinical complaints, such as fever, fatigue, and myalgia [4]. Despite the low PTP of CAD and young age, an abnormal change in the ECG with typical chest symptoms of ACS, including dyspnea, which was recently included in the updated PTP classification of the European Society of Cardiology guideline for chronic coronary syndrome [5], should be particularly suspected of being indicative of CAD. Another important clinical point that we learned from the two cases was that ICA may not always be the first diagnostic strategy for ACS, especially when it is secondary to TA, because improper manipulation during ICA can result in ventricular fibrillation and SCD [6]. Coronary CTA is an excellent noninvasive modality for the evaluation of coronary artery ostium lesions [7], but it is not recommended for patients with ACS as per the current guidelines [8]. Nevertheless, coronary CTA may be the first choice to identify ostial coronary stenosis and aortic wall thickness among patients suspected of having TA. Coronary CTA can detect aortic wall thickening that could not be detected by echocardiography, as observed in these cases. Furthermore, because CABG is recommended for the revascularization of CAD in TA [9], coronary CTA can be a substitute for ICA for the assessment of arteries for bypass grafting. A previous case report has also shown that CT is useful in managing arteritis [10]. Therefore, coronary CTA may aid in the detection of aortic wall inflammation for rapid decision making among patients suspected of having TA presenting as ACS. It might help avoid serious complications associated with coronary artery manipulation. We suggest that coronary CTA can be performed first in patients with ACS who present with typical symptoms and ECG changes but have a low PTP of CAD, even if they do not meet the diagnostic criteria for TA.

Declaration of competing interest

The authors declare that there is no conflict of interest.

Appendix A. Supplementary data

Supplementary Video 1

Initial right coronary artery angiography of patient 1.

Supplementary Video 2

Significant stenosis of the right coronary artery ostium in patient 1.

Supplementary Video 3

Left coronary artery angiography of patient 1 wtihout catheter engagement of the left coronary artery ostium.

Supplementary Video 4

Left coronary artery angiography of patient 1 wtih catheter engagement of the left coronary artery ostium.