Abstract
Spontaneous coronary artery dissection (SCAD) is becoming widely recognized as an important cause of myocardial infarction, particularly in younger women. Tendency toward conservative management has been primarily based on observational data. Intervention is recommended when coronary blood flow is compromised and high risk features such as left main involvement, ongoing ischemia, or hemodynamic or electrical instability are present. Unlike the atherosclerotic process where the superiority of stenting compared with plain old balloon angioplasty has been established in the acute setting, randomized studies for revascularization strategies for spontaneous coronary dissection are currently lacking. We highlight 4 cases of SCAD from our institution, review the literature with regard to percutaneous revascularization in this population, and propose a step-wise algorithm for percutaneous intervention strategies in managing higher-risk SCAD.
Highlights
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Intervention is recommended in spontaneous coronary artery dissection (SCAD) in the presence of high risk features such as ongoing ischemia, left main involvement, or hemodynamic or electrical instability.
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Revascularization success in spontaneous coronary artery dissection is highly variable and fraught with technical challenges.
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Randomized data with regard to revascularization methods in higher risk SCAD is currently lacking.
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Spontaneous coronary dissections have a tendency to heal on their own, and placement of drug eluting stents puts patients at increased risks of stent thrombosis, stenosis, and long-term antiplatelet therapy.
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We propose a step-wise algorithm that starts with plain old balloon angioplasty to restore coronary blood flow, and only escalating to careful use of a cutting balloon and then to placement of drug eluting stent should coronary blood flow remain compromised in these higher risk SCAD patients.
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Introduction
Spontaneous coronary artery dissection (SCAD) is becoming widely recognized as an important cause of myocardial infarction in younger women. Observational studies have reported a prevalence of SCAD ranging between 22 and 43% in young women presenting with acute coronary syndrome . Management has been primarily based on expert opinions from observational data. These studies have shown that SCAD tend to heal spontaneously in many instances and because revascularization success is highly variable, a conservative approach is recommended .
Intervention is recommended when blood flow is compromised and in the presence of high risk features such as left main dissection, ongoing ischemia or chest pain, or hemodynamic or electrical instability are present. However, there is no consensus on the method of revascularization. There are no randomized data comparing differing revascularization strategies, for instance, comparing outcomes of balloon angioplasty vs. drug eluting stents. Observational studies have demonstrated lower success rates with percutaneous intervention (PCI) in this patient population, ranging from 47 to 80% . We highlight 4 cases of higher risk SCAD from our institution, review current literature with regard to revascularization methods, and propose an algorithm for PCI strategies in the management of SCAD.
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Case 1
A 38-year-old African American woman with a history of asthma and gestational hypertension presented with acute, sudden onset chest pain with radiation to her left shoulder. Electrocardiogram (ECG) showed non-specific ST and T wave changes with an elevated troponin-I level of 2.4 ng/mL. With progressive and worsening chest pain, coronary angiogram was urgently pursued, which showed a 90% stenosis in the mid left anterior descending (LAD) segment followed by a distal, smaller-caliber vessel with TIMI-3 flow ( Fig. 1 ). A 2.75 × 18 mm drug eluting stent was deployed to the mid LAD segment, and the patient was admitted to the coronary care unit. The patient returned to the catheterization lab the following day for recurrent chest pain. Angiogram showed propagation of the dissection both proximal and distal to the stent. A second drug eluting stent was placed proximal to the first with improvement in TIMI flow to the distal LAD. The patient continued to have recurring chest pain, and underwent a third coronary angiogram on hospital day #3; a spiral dissection of the LAD distal to the first stent was seen. The stents themselves were widely patent and there was no evidence of dissection propagation proximal to the stents. After extensive discussion with cardiothoracic surgery team, as she was more than 24 h post infarct, no further intervention was pursued and patient was medically managed with eventual resolution of her chest pain. On discharge, echocardiogram demonstrated an ejection fraction of 34–50% with apical akinesis.
2
Case 1
A 38-year-old African American woman with a history of asthma and gestational hypertension presented with acute, sudden onset chest pain with radiation to her left shoulder. Electrocardiogram (ECG) showed non-specific ST and T wave changes with an elevated troponin-I level of 2.4 ng/mL. With progressive and worsening chest pain, coronary angiogram was urgently pursued, which showed a 90% stenosis in the mid left anterior descending (LAD) segment followed by a distal, smaller-caliber vessel with TIMI-3 flow ( Fig. 1 ). A 2.75 × 18 mm drug eluting stent was deployed to the mid LAD segment, and the patient was admitted to the coronary care unit. The patient returned to the catheterization lab the following day for recurrent chest pain. Angiogram showed propagation of the dissection both proximal and distal to the stent. A second drug eluting stent was placed proximal to the first with improvement in TIMI flow to the distal LAD. The patient continued to have recurring chest pain, and underwent a third coronary angiogram on hospital day #3; a spiral dissection of the LAD distal to the first stent was seen. The stents themselves were widely patent and there was no evidence of dissection propagation proximal to the stents. After extensive discussion with cardiothoracic surgery team, as she was more than 24 h post infarct, no further intervention was pursued and patient was medically managed with eventual resolution of her chest pain. On discharge, echocardiogram demonstrated an ejection fraction of 34–50% with apical akinesis.
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Case 2
A 39-year-old African American, post-partum woman presented with acute onset substernal chest pain. She recently underwent caesarian section delivery 1 week prior to presentation. ECG showed 2 mm ST segment elevations in the inferior leads and reciprocal ST depressions in the precordial leads. Troponin-I level was elevated to 16.2 ng/mL. Emergent coronary angiogram demonstrated an extensive coronary dissection from the ostial right coronary artery (RCA) to the distal segment. A dissection flap with multiple radiolucent lumens was visualized in the proximal and mid RCA, followed by a high grade diffuse narrowing in the mid to distal segments. Multiple, prolonged inflations with a 3.50 × 30 mm balloon were performed throughout the RCA. TIMI-3 flow was achieved and the final angiographic result as shown in Fig. 2 . The patient was discharged home on day 7.
