Spontaneous Coronary Artery Dissection Involving the Left Main with Extension to Left Anterior Descending Artery and Left Circumflex Artery: Diagnostic and Management Challenges

Figure 1. The ECG of a 43-year-old female patient presenting to the Emergency Department (ED) with recurrent retrosternal chest pain at rest, radiating to the back, lasting approximately 10 minutes, showing no significant ST-T changes. Physical exam didn’t reveal any pathological signs, blood pressure was 120/60 mmHg bilaterally, heart rate 60 beats per minute. Echocardiography revealed akinesia of one third of the anterior, inferior, lateral walls and septum, with an estimated ejection fraction of 45%. There was no pericardial effusion noted and the aorta had normal dimensions and no intimal flap. Serological results showed normal cardiac necrosis markers. Of note, the patient denied significant medical family history. She was being treated for chronic anxiety.

Figure 2. Seeing as the patient had a low suspicion for atherosclerotic disease, we firstly performed a CT coronary angiography (CTCA) which revealed a significant stenosis of the left anterior descending artery (LAD).

Figure 3. The patient later experienced another episode of resting chest pain. An ECG performed at that time revealed deep, diffuse negative T waves in V1-V6, DI, DII, aVL and aVF.

Figure 4. Subsequent ECGs demonstrated evolution of the ST-T segment, consistent with a Wellens syndrome pattern. Cardiac necrosis markers increased.

Figure 5. We performed urgent coronarography which, surprisingly, revealed mild, smooth stenoses located in the proximal segments of the LAD and Cx coronary arteries (solid arrows) along with distal occlusions in LAD and diagonal branch (dashed arrows).

Figure 6. Given the striking discrepancies between the patient’s symptoms, ECG and CTCA results, we decided to further investigate and an intravascular ultrasound (IVUS) was performed. It revealed spontaneous coronary artery dissection in the distal left main artery, with extensions in the LAD and proximal circumflex arteries, with hematomas present, classified as a type 2a. Given that the hematomas were most likely favorized by parenteral anticoagulation, we withdrew this medication, maintaining dual antiplatelet therapy with aspirin and clopidogrel. Conservative management was chosen for this patient because she was hemodynamically stable and angina free at the moment of coronarography. She was discharged in good health with minimal cardiac medication (aspirin, clopidogrel, beta-blocker, ACE inhibitor and statin) and scheduled for a follow-up coronarography at the 3-month mark (which have not elapsed at the moment of writing this article). The true incidence of spontaneous coronary artery dissection (SCAD) remains uncertain, but it is increasingly recognized as a cause of acute coronary syndrome (ACS) particularly in young to middle-aged women [1,2]. There are several known predisposing factors for SCAD: systemic inflammatory conditions, hormonal therapy, fibromuscular dysplasia, postpartum status, multiparity (≥4 births), connective tissue disorders [3]. Beside these predisposing factors, certain triggers can precede the anginal episode, such as emotional stress, exercise or hormonal changes (in vitro fertilization [4], hormonal replacement therapy [5], hormonal therapy in transgender individuals [6], oral contraception [7]) [8]. Management of spontaneous coronary dissection isn’t completely clarified. Both the European Society of Cardiology (ESC) and the American Heart Association (AHA) have published reports with recommendations. Both reports highlight conservative management as the preferred strategy [2,9]. The ESC states high healing rates over time (73%-100%), and the AHA emphasizes some cases need repeat angiography to confirm healing, typically after 35 days. Revascularization may be challenging due to fragile coronary vessel wall and angioplasty may have worse outcomes compared to atherosclerotic coronary disease. Close monitoring after the index event is recommended by both associations [2,9], with the AHA preferring extended inpatient monitoring for up to 7 days [9]. According to the ESC, 3.3% of conservatively managed patients may require revascularization during follow-up [2]. AHA states that the first 7 days are critical as patients may experience recurrent MI and need emergency revascularization [9]. In regards to percutaneous coronary intervention (PCI), both reports state that angioplasty is associates with significant complications (false lumen propagation, iatrogenic dissection) and procedural failure (stent restenosis and thrombosis) which may need emergent coronary artery by-pass graft (CABG) [2,9]. In general, angioplasty should only be attempted if strictly necessary. Both ESC and AHA agree that CABG is reserved as a bail-out strategy when PCI fails, especially in cases of ongoing ischaemia, infarction, or technical failure (e.g., inability to wire the true lumen). Left main coronary artery involvement or multiple dissections could require CABG [2,9]. CABG complications are graft failure which can occur due to competitive flow due to the healing of the native coronary artery. CABG does not prevent recurrent SCAD. When performing CABG one of the main concerns is anastomosis to the true lumen. AHA emphasizes conservative strategy when it comes to stable patients [9]. Given that SCAD involve bleeding and hematoma formation, the use of traditional acute coronary syndrome drugs such as antiaggregant and anticoagulation is controversial. In regards to antiplatelet therapy, aspiring and clopidogrel are preferred. While the ESC endorses dual antiplatelet therapy (DAPT) [2], the AHA is reserved due to lack of evidence and recommends single antiplatelet therapy (SAPT) in patients not undergoing PCI [9]. Both guidelines raise concerns about anticoagulation due to increased bleeding risk [2,9]. The AHA recommends discontinuation of anticoagulation therapy unless it is necessary for other comorbidities [9]. Statins are not particularly useful in SCAD due to its non-atherosclerotic pathophysiology. Statins can be recommended if the patient has dyslipidemia or diabetes. Hormonal contraception and hormone replacement therapy carry a potential risk for SCAD, especially since SCAD occurs often in young women, including during pregnancy or postpartum. Evidence in this direction is inconclusive and a causal link has not been established. Ischemia relief can be obtained using traditional antianginal medication (nitrates, calcium channel blockers).