Abstract
Spontaneous coronary artery dissection (SCAD) is a rare cause of acute coronary syndrome. Treatment for SCAD includes conservative approaches, percutaneous coronary intervention (PCI), and coronary artery bypass graft surgery. Although the success rate of PCI is low, conservative treatment often leads to a good clinical course. Three patients with SCAD who were conservatively treated with intra-aortic balloon pumping without coronary intervention are presented. All three patients continue to do well.
< Learning objective: The treatment for spontaneous coronary artery dissection (SCAD) has not yet been established. Intra-aortic balloon pumping (IABP) is a potential conservative treatment for SCAD that increases coronary blood flow. However, IABP could worsen the dissection. In this report, IABP was safely used for SCAD and patients had a good clinical course without worsening the dissection.>
Introduction
Percutaneous coronary intervention (PCI) is an established treatment for acute myocardial infarction (AMI). Spontaneous coronary artery dissection (SCAD) is rare, accounting for 0.1–0.4% of all instances of acute coronary syndrome (ACS) . Since PCI is difficult for patients with SCAD and the success rate is relatively low , patients are often treated conservatively. Intra-aortic balloon pumping (IABP) can increase aortic diastolic pressure, accelerating coronary blood flow and improving myocardial ischemia . However, whether IABP is safe for SCAD has not been established. Three patients whose clinical course was good after conservative treatment using IABP to treat ACS caused by SCAD are presented.
Case 1
A 39-year-old woman was admitted with chest pain. Her blood pressure was 91/47 mmHg, heart rate was 77 beats/min (bpm). Chest examination was unremarkable. Electrocardiography (ECG) showed sinus rhythm with ST elevation in leads I and aV L , an abnormal Q wave and T wave inversion in V 1–4 , and ST depression in leads II, III, and aV F . Her creatine kinase (CK) and CK-MB values were 532 and 218 IU/L. She had been treated with estrogen and progesterone for infertility, and she had no coronary risk factors. Transthoracic echocardiography (TTE) showed reduced contraction of anterior septum. Emergency coronary angiography (CAG) showed diffuse stenosis from the left main trunk (LMT) to the proximal left anterior descending artery (LAD), and severe stenosis with thrombolysis in myocardial infarction (TIMI)-1 flow in the first diagonal branch ( Fig. 1 A). Intravascular ultrasound (IVUS) of the LAD-LMT verified the absence of atherosclerosis, but detected an intramural hematoma with a narrow true lumen ( Fig. 1 B), indicating type 2 SCAD. IABP was started to increase blood pressure in the true lumen. The diameter of the mid-segment of the LMT was measured using IVUS when IABP was switched on and off. The true lumen diameter was 3.5 × 2.0 and 2.9 × 1.5 mm when the IABP was on and off, respectively ( Fig. 1 C, D). Thus, IABP increased the true lumen pressure, and it was decided to treat this patient conservatively with IABP. The peak CK value was 2337 IU/L. The CAG and IVUS studies were repeated on day 9; the dissection was partially improved, and the true lumen of the LMT was expanded on IVUS ( Fig. 1 E, F). She was discharged without any symptoms on day 33. Three months after admission, CAG showed complete resolution of the LMT-LAD lesion. Coronary artery spasm was not provoked with ergonovine at one-year admission. The patient continues to have good clinical status.
Case 2
A 37-year-old woman with chest pain was admitted with suspected AMI. Physical and laboratory findings were unremarkable. ECG showed sinus rhythm of 65 bpm, with ST elevation in leads II, III, and aV F , and ST depression in V 2–4 . TTE showed normal left ventricular wall motion. She had delivered her second child nine months before admission. She was not under medication and had no coronary risk factors. Emergency CAG showed severe stenosis of the first marginal branch with extramural contrast filling in the vessel wall with contrast delay ( Fig. 2 A), indicating type 1 SCAD. Left ventriculography (LVG) demonstrated mild hypokinesis in the posterolateral segment. IVUS suggested that the hematoma narrowed the true lumen ( Fig. 2 B). IABP was inserted, and conservative therapy proceeded. Blood flow in the first marginal branch increased partially after the IABP started to work. The true lumen diameter in the proximal edge of the dissection in the first marginal branch was 1.9 × 1.7 and 1.9 × 1.7 mm when IABP was on and off, respectively ( Fig. 2 C-E). When IABP was on and off, there was almost no change in lumen and vessel diameters. However, only the proximal edge of SCAD could be shown by IVUS because of the accordion phenomenon. Therefore, the effect of IABP was unclear. The CK level peaked at 809 IU/L. The next day, CAG showed that flow in the first marginal branch increased and she remained asymptomatic. Cardiac catheterization on day 19 showed TIMI-3 flow in the first marginal branch and normalized left ventricular function. She was discharged home on day 21. A fourth CAG 110 days after admission showed partial resolution of the dissection ( Fig. 2 F). Computed tomography (CT) was performed on day 98 and a year later. A year later, the dissociation cavity had further improved, but remained slightly ( Fig. 2 G-J). She has remained event-free at three-year follow-up.
