Delayed presentation of left main coronary artery dissection due to catheter ablation in a patient with bicuspid aortic valve. Coincidence or manifestation of inherent vulnerability?

Abstract

Left main coronary artery (LMCA) injury is an uncommon complication of catheter ablation. Due to the large myocardial area at risk, its presentation is usually acute with a dramatic course and life-threatening sequelae. Increased susceptibility to spontaneous coronary artery dissection has recently been implied in patients with bicuspid aortic valve (BAV). We present the first case of iatrogenic coronary dissection in a BAV patient, with an atypically delayed manifestation. The patient sustained ablation catheter-induced mechanical damage of LMCA due to its inadvertent penetration during the attempts to cross the aortic valve. After three days of recurring chest pain, he was readmitted with anterior myocardial infarction and imminent cardiogenic shock, and underwent emergent coronary stenting.

Literature review suggests that in BAV inherent susceptibility to both spontaneous and iatrogenic coronary dissection may exist. Therefore, we advocate that in BAV extreme caution should be exercised during electrophysiological procedures involving the coronary artery cannulation for tagging or pace mapping, or when the left ventricle is to be entered retrogradely, and likewise in percutaneous coronary interventions. Such patients may be doubly predisposed to iatrogenic injury; firstly, by more difficult catheter manipulation in the malformed aortic cusps, and secondly, by the underlying vulnerability of coronary ostia.

<Learning objective: Arteriopathy in bicuspid aortic valve (BAV) is not limited to the aorta. It is considered a connective tissue disease predisposing to spontaneous coronary artery dissection. This predisposition may also render the patients more vulnerable to iatrogenic dissection.

Ablation in the aortic cusps or with the aortic valve crossing, and percutaneous coronary interventions may require special precautions in the BAV population.

Physicians attending post-ablation patients should be aware of a delayed coronary artery occlusion risk.>

Introduction

Coronary artery damage is rarely observed during catheter ablation of arrhythmia. When the left main coronary artery (LMCA) and the left anterior descending coronary artery (LAD) are injured, the presentation is typically acute/subacute due to the vast myocardial territory supplied by the vessels. It usually manifests as chest pain with life-threatening ventricular arrhythmias, cardiogenic shock, or sudden cardiac arrest [1]. Prompt diagnosis and urgent treatment are required to save the patient.

Recent studies suggest that bicuspid aortic valve (BAV) is a condition predisposing to spontaneous coronary artery dissection [2]. The underlying susceptibility to spontaneous dissection may also render coronary arteries more vulnerable to catheter-induced injury.

With BAV being the most prevalent congenital heart disease (estimated incidence of 1–2%) and the constantly growing number of transaortic electrophysiological procedures and percutaneous coronary interventions, a substantial population may be at inherently increased risk of iatrogenic coronary dissection.

Case report

A 27-year-old man was admitted to our department due to recurrent chest pain with concomitant weakness and vomiting. In the electrocardiogram (ECG), sinus tachycardia with ST segment elevation in anterior precordial leads was found. His blood pressure was 80/50 mmHg and required dopamine infusion. In echocardiography, the ejection fraction was 30–35%, with akinetic interventricular septum and all apical segments, and hypokinetic anterior wall. High-sensitivity troponin T on admission was 6.34 (upper limit of normal: 0.014). Acute myocardial infarction with imminent cardiogenic shock was diagnosed. His medical history included BAV, subarachnoid hemorrhage, Wolff-Parkinson-White syndrome with two attempts of transseptal radiofrequency (RF) ablation (4 and 7 months before admission), and transaortic redo ablation performed 3 days earlier at a tertiary center.

We proceeded with urgent coronary angiography, in which LAD occlusion was found with haziness in its proximal segment, and an extraluminal, round-shaped penetration of dye at the LMCA bifurcation (Fig. 1a, Online Videos 1, 2 in Supplementary material). The left circumflex artery (LCx) and a large intermediate branch (IM) were without obstruction. Intravascular ultrasound (IVUS) examination was performed to confirm and assess the extent of the suspected coronary dissection. The dissection entry site with a moving flap was found at the LMCA bifurcation (Fig. 1b, Online Video 3 in Supplementary material). The dissection extended down to the 1st diagonal branch origin. In IVUS, the collapsed true lumen of LAD with thrombosis of the false lumen was seen (Fig. 2c–d, Online Video 3 in Supplementary material). Fortunately, the dissection did not propagate retrogradely into the aortic root and the ascending aorta, as confirmed later by transesophageal echocardiography.

Fig. 1.

(a) Angiographic image (LAO 7° CAUD 30°) of the left anterior descending artery (LAD) proximal occlusion (horizontal arrow) with a pinhead-shaped extraluminal dye penetration just before the vessel origin (vertical arrow) as a presumed site of the ablation catheter impact. IM, intermediate branch; LCx, left circumflex artery (guiding catheter: EBU 3.5 6 French). (b) Intravascular ultrasound image of the dissection entry site in the left main coronary artery (LMCA), with an intimal flap (arrow). (c) LMCA bifurcation with the intramural hematoma (asterisk) in LAD and the uncompromised LCx. (d) Mid-LAD with the collapsed true lumen (TL) compressed by the thrombosed false lumen (FL).

Fig. 2.

(a) Angiographic image (LAO 0° CRAN 40°) of the final result after stents deployment; IM, the intermediate branch; LAD, left anterior descending artery; LCx, left circumflex artery. (b) Intravascular ultrasound image of self-expanding stent apposition in the 6-mm-wide left main coronary artery. (c) 3-month control angiography (LAO 27° CAUD 20°) showing stents’ patency and the unobstructed LCx and IM ostia.

Due to LMCA large diameter (6 mm), a self-expanding stent Stentys 3.5–4.5/25 mm (Stentys SA, Paris, France) was implanted from LMCA into LAD. The distal part of the dissection was covered with an overlapping drug-eluting stent. Thrombolysis in myocardial infarction 3 flow was achieved, yet with poor myocardial blush (Fig. 2a, Online Video 4 in Supplementary material). LCx and IM ostia were not compromised by the stent. The latter and the adequate stents’ apposition were checked in IVUS (Fig. 2b, Online Video 5 in Supplementary material).

As reported by the electrophysiologist, the left posterolateral accessory pathway had been ablated by retrograde approach, with RF applications performed in the left ventricle near the mitral valve annulus. The EnSite cardiac mapping system (St. Jude Medical, St. Paul, MN, USA) had been utilized. In the preprocedural echocardiography, the aortic root dilatation and valve stenosis were not found (only mild regurgitation) (Fig. 3a, Online Video 6 in Supplementary material). According to the operator, significant difficulties had been encountered while crossing the aortic valve, requiring extensive manipulation, and thus inadvertent LMCA penetration during 7 French Thermocool catheter introduction could be assumed post hoc. However, catheter insertion into LMCA had not been suspected during the procedure. LMCA had not been intentionally entered to tag its position on an electroanatomical map. The catheter position in the left ventricle had been stable and dislodgement into the aorta during energy application had been ruled out. After the procedure, the patient had complained of persistent chest pain. Due to ECG changes (minor ST-segment elevation in leads V4-V6), echocardiographic examination had been performed but had shown normal contractility and no pericardial effusion. In ECG, preexcitation had recurred on the following day.

Fig. 3.

(a) Transthoracic echocardiography of the aortic root in parasternal long-axis view with width measurement at the sinuses of Valsalva (SoV) level. (b) Parasternal short-axis echocardiographic view in diastole, showing the patient’s bicuspid aortic valve (BAV) with nearly equal cusp size and right-left orientation of the commissure. BAV type 1, i.e. with fused right and left coronary cusps without raphe can be seen. (c) Schematic representation of type 1 rapheless BAV. LMCA, left main coronary artery; NCC, non-coronary cusp; RCA, right coronary artery.

After stenting, the patient recovered and was discharged eight days later. Repeat angiography after 3 months confirmed stents’ patency in LMCA-LAD and unobstructed LCx (Fig. 2c, Online Video 7 in Supplementary material). The patient declined implantable cardioverter-defibrillator (ICD). One year later, he was resuscitated due to ventricular fibrillation. In angiography, a good long-term result of LMCA-LAD stenting was found. ICD was eventually implanted. One month later, another episode of ventricular fibrillation occurred with adequate ICD intervention. The patient has been suffering from exertional dyspnea since the infarction.

Discussion

Along with cardiac tamponade and atrioesophageal fistula, coronary artery injury is among the most dire and potentially lethal complications of catheter ablation. In cases of LMCA trauma with acute/subacute presentation, in-hospital mortality has been assessed as 32% [1]. Due to the large area of myocardium at risk, LMCA and LAD injury causing flow deterioration typically manifests during an ablation procedure or shortly after its termination. The unusually late presentation in our patient may have been the result of gradual propagation and thrombosis of intramural hematoma after the intraprocedural LMCA bifurcation’s spot damage. Seven French ablation catheter would have been easily accommodated by the 6-mm LMCA of our patient. The extraluminal cap of dye visible just before LAD origin had most likely been the impact site. As observed during complicated by dissection coronary interventions and retrograde ablation procedures, the cranial surface of LMCA is the place of catheter tip impact, as catheters are naturally pointed in this direction by their curves and the aortic cusp backup [1]. In a retrospective analysis of 26 cases of LMCA injury during ablation, unintended catheter insertion was inferred in 73%, with 95% of the latter having involved the aortic valve crossing (only in 18% LMCA penetration had been realized before symptoms/ECG changes developed) [1]. Moreover, spontaneous coronary artery dissections (SCAD) predominantly affect mid-to-distal segments [2]. Although we cannot unequivocally exclude stress-induced spontaneous dissection in this patient, the course of events, high proximal location of dissection entry, and the extraluminal outpouching strongly suggest iatrogenic etiology.

The delayed presentation raises some important issues. Patients after electrophysiological procedures usually stay overnight in hospital with next-day discharge, as was the case in our patient. Chest pain or discomfort are typical complaints after ablation procedures and are not specific to ischemia in this population. In patients with ablation performed near a coronary artery ostium or its anatomic course, prolonged monitoring and follow-up with a low threshold for ischemia diagnostic tests should be considered.

Another important aspect of our case is the coincidence of BAV and iatrogenic coronary artery dissection. BAV is regarded as a heritable disorder of connective tissue and is associated with cystic medial degeneration that can lead to the progressive dilation of the aortic root as well as aneurysm and dissection of the ascending aorta. Arteriopathy in BAV is not limited to the aorta; intracranial aneurysms and spontaneous dissections of the cervical and intracranial arteries have been described in this population [3]. During retrograde electrophysiological studies, LMCA is sometimes intentionally entered to mark and tag its location on a three-dimensional electroanatomical map, or to perform pace-mapping. Even with its inadvertent and uncontrolled penetration, LMCA damage is not an inevitable consequence, particularly in young patients without atherosclerotic lesions. However, a malformed bicuspid aortic valve may prove more difficult to cross, increasing the risk of forceful LMCA intubation with a rather stiff ablation catheter. Moreover, recent studies suggest that coronary arteries may be more dissection-prone in patients with BAV. In the 2018 American Heart Association statement on SCAD, BAV was included in the screening list among other connective tissue disorders such as Marfan and Ehlers-Danlos syndrome, association of which with SCAD is well established [2]. However, only few cases of SCAD afflicting patients with BAV have been published so far [4], [5], [6]. As recently found, patients with SCAD, admittedly a heterogenous group, have also >17-fold higher incidence of catheter-induced coronary artery dissections [7].

As mentioned by Andreou, there may exist a common underlying defect in patients with BAV, as the aortic cusps, musculoconnective tissue of the ascending aorta, and the aortic arch all derive from the neural crest cells (NCCs), whose malfunction is a proposed pathogenetic factor in the most prevalent BAV type 1, i.e. with fused right and left coronary leaflets (found in our patient) (Fig. 3b, c) [8], [9]. The NCCs also directly contribute to the formation of vascular smooth muscle cells of the ostial regions of coronary arteries and play a regulatory role in the whole coronary artery development, with some coronary variants and anomalies more prevalent in BAV populations [2], [10].

Patients with BAV may thus be doubly predisposed to iatrogenic coronary artery injury: firstly, by more difficult catheter manipulation in the malformed aortic cusps with their distorted geometry, and secondly, by the inherent susceptibility to coronary dissection. As BAV is the most prevalent congenital heart disease, our observation suggests that during electrophysiological procedures requiring the aortic valve crossing, or performed near the coronary ostia, and in percutaneous coronary interventions, particular caution should be employed to prevent potentially fatal complications.

The reported case should also warn physicians attending post-ablation patients of the risk of a delayed coronary artery occlusion. In patients with recurring or protracted chest pain, prolonged monitoring and repeated check-up should be mandatory after procedures with an increased risk of a major coronary artery damage.

Conflict of interest statement

The authors declare that there is no conflict of interest.

Appendix A. Supplementary data

The following are Supplementary data to this article: