Coronary Artery Dissections






  • Key Points


  • ▪

    The conventional test of choice to identify coronary artery dissections is standard coronary angiography.


  • ▪

    Cardiac CT angiography shows some early ability to depict coronary artery dissection; validation is limited.


Although coronary artery dissections are rare overall (0.1–0.3% incidence in angiographic series), when they do occur it is usually within the settings of the pregnant or peripartum state, blunt chest trauma, iatrogenesis, or severe exertion or stress, or associated with one of several medical conditions (see Etiologies and Associations).


Coronary artery dissections may be single or multiple and may involve all three coronary arteries and the left main stem coronary artery.


Repeated angiography may reveal regression or healing, although progression has been described, as has recurrence, and conventional catheter-based angiography may initiate coronary artery dissection.


Some coronary artery dissections, usually iatrogenic ones, may propagate retrograde back into the aortic root. Most spontaneous coronary artery dissections remain within the coronary tree.




Etiologies and Associations




  • □

    Hormone-associated



    • •

      Oral contraception–related


    • •

      Pregnancy-associated



      • •

        Mid-term


      • •

        Third trimester


      • •

        Twin pregnancy



    • •

      Peri-/postpartum–associated


    • •

      Post-abortion


    • •

      Menstruation-associated


    • •

      Postmenopausal



  • □

    Nonhormone-associated



    • •

      Iatrogenic



      • •

        Coronary angiography


      • •

        Percutaneous coronary intervention



        • •

          Plain old balloon angioplasty (POBA)


        • •

          Coronary artery stenting (bare metal; drug-eluting)


        • •

          Cutting balloon


        • •

          Intracoronary radiation


        • •

          Intravascular ultrasound (IVUS)



      • •

        Cryoablation for atrial fibrillation


      • •

        Coronary artery bypass grafting



    • •

      Drug abuse–associated



      • •

        Cocaine abuse


      • •

        Ergotamine abuse



    • •

      Drug-associated



      • •

        Fenfluramine


      • •

        5-FU



    • •

      Hypertension-associated



      • •

        Retching-associated


      • •

        Weight-lifting–associated



    • •

      Acute aortic dissection (type A)


    • •

      Acute aortic dissection, despite repair of the dissected aorta


    • •

      Supravalvular aortic stenosis


    • •

      Disease-associated



      • •

        Active inflammatory bowel disease


      • •

        Systemic lupus erythematosus


      • •

        Polycystic kidney disease


      • •

        Renal transplantation–associated


      • •

        Anti-phospholipid antibody


      • •

        Alpha-1 antitrypsin–associated


      • •

        Pulmonary embolism



    • •

      Vascular disease–associated



      • •

        Eosinophilic monoarteritis


      • •

        Fibromuscular dysplasia


      • •

        Coronary ectasia



    • •

      Inheritable connective tissue disorder



      • •

        Marfan syndrome


      • •

        Cystic medial necrosis



    • •

      Exertion



      • •

        Skiing at altitude


      • •

        Wrestling


      • •

        Exercise/athleticism/strenuous workouts



    • •

      Neurofibromatosis (type 1—vasculopathy-associated)


    • •

      Stress-associated



      • •

        Sleep deprivation (72 hours)


      • •

        Depression


      • •

        Emotional stress



    • •

      Sexual intercourse


    • •

      Blunt chest trauma






Clinical Presentations of Spontaneous Dissections




  • □

    Chest pain


  • □

    Stable angina (likely due to organization/evolution of dissection into a coronary artery stenosis or occlusion)


  • □

    Acute coronary syndrome


  • □

    Myocardial infarction (MI)



    • •

      ST-elevation myocardial infarction (STEMI)


    • •

      Non-STEMI



  • □

    Transient ST elevation


  • □

    Sudden death


  • □

    Atrial fibrillation and tamponade due to rupture of the dissected artery


  • □

    Tamponade due to rupture of the dissected artery


  • □

    Aortic dissection–like


  • □

    Stroke (due to coronary dissection resulting in MI)



Ischemic presentations dominate. It has been suggested that inadvertent use of thrombolytics for STEMI due to spontaneous coronary dissection may predispose the coronary dissection to extension. Arrhythmic presentations and sudden death are relatively common for this diagnosis. Rupture of the artery with tamponade has been described, as have other indirect complications or presentations. Multivascular occurrences (e.g., stroke, renovascular disease) should prompt consideration of vasculitides, including the inheritable variants and fibromuscular dysplasia.




Treatment




  • □

    Observation and medical treatment, without or with repeat imaging


  • □

    Stenting


  • □

    Surgical bypass or repair





Diagnostic Testing for Coronary Dissections


Conventional angiography has been and remains the standard diagnostic test to diagnose coronary artery dissections, although, unfortunately, it may also cause coronary dissection. IVUS, performed at the time of angiography, is able to visualize a subset of coronary dissection cases that are ambiguously represented on angiography. Transesophageal echocardiography (TEE) has detected spontaneous coronary dissection, but would be expected to have very limited ability to interrogate the coronary tree. TEE would be able to image dissection of the aorta extending into a coronary artery, or coronary dissection extending into the aortic root.


Coronary CT angiography (CTA) has been used to image coronary artery dissections (see Figures 12-1 through 12-10 ).




Figure 12-1


A 44-year-old woman presents with an acute coronary syndrome (ACS). Conventional coronary angiography demonstrates a normal left main and left anterior descending (LAD) coronary arteries ( A ), but with faint collateralization to the posterior descending coronary artery (PDA), primarily via septal perforators ( B ). C and D, Poor opacification of the right coronary artery (RCA) with an RCA dissection involving the proximal to mid-RCA. See Figure 12-2 .



Figure 12-2


Same case as Figure 12-1 . A – D, Multiple curved reformations from a cardiac CT confirm a normal left anterior descending artery and right coronary artery dissection with contrast in both lumens well demonstrated. Additionally, multifocal “beaded” stenoses in the posterior descending coronary artery are seen. These are not associated with any soft or calcified plaque and are suspicious for coronary artery involvement with fibromuscular dysplasia, and its basis or cause of the coronary dissection. E – F, Maximum intensity projection images from renal gadolinium-enhanced magnetic resonance angiography demonstrate mild beaded irregularity of the right renal artery consistent with fibromuscular dysplasia.



Figure 12-3


A 32-year-old woman 4 weeks postpartum presents with chest pain, toponin elevation, and an abnormal ECG. Apical akinesis was identified on echocardiography. The first and second ECGs on the first and second days in the hospital reveal evolution from extensive mild repolarization abnormalities to obviously biphasic T waves. Conventional angiographic images demonstrate a small localized mid- to distal left anterior descending artery dissection with akinesis of the left ventricular apex.



Figure 12-4


A 39-year-old woman with a bicuspid aortic valve, chest pain, and left main coronary artery dissection seen at conventional coronary angiography. Follow-up cardiac CT demonstrates a localized left main coronary artery dissection with a small associated false aneurysm. The false aneurysm has a small amount of thrombus within it. The patient went on to coronary artery bypass grafting (CABG). LAD, left anterior descending artery. See Figure 12-5 .



Figure 12-5


Same case as Figure 12-4 . Ongoing intermittent chest pain associated with evolving ECG repolarization changes and rising troponin levels led to CT angiography evaluation 2 days later to rule out proximal extension of the dissection, or dissection of another vessel. Axial source images windowed differently demonstrate two contrast-filled lumina within the mid distal left anterior descending artery. Curved reformats demonstrate the focal dissection with no evidence of proximal or distal extension. Note how the dissection is “sandwiched” between two regions of superficial myocardial bridging.



Figure 12-6


A 5-mm dissection is present in the proximal right coronary artery, seen on these curved multiplanar images and an intravascular ultrasound image.

Tags:
Apr 10, 2019 | Posted by in COMPUTERIZED TOMOGRAPHY | Comments Off on Coronary Artery Dissections

Full access? Get Clinical Tree
Get Clinical Tree app for offline access