65. Case Report: Spontaneous Coronary Artery Dissection (SCAD) Requiring Heart Transplantation – UCLA

CardioNerds (Amit Goyal & Daniel Ambinder) join join UCLA cardiology fellows (Jay Patel, Hillary Shapiro, and Ruth Hsiao) for some beach bonfire in Santa Monica! They discuss a challenging case of Spontaneous Coronary Artery Dissection (SCAD) requiring heart transplantation. Dr. Jonathan Tobis provides the E-CPR and program director Dr. Karol Watson provides a message for applicants. Episode notes were developed by Johns Hopkins internal medicine resident Evelyn Song with mentorship from University of Maryland cardiology fellow Karan Desai. Jump to: Patient summary - Case media - Case teaching - References Episode graphic by Dr. Carine Hamo The CardioNerds Cardiology Case Reports series shines light on the hidden curriculum of medical storytelling. We learn together while discussing fascinating cases in this fun, engaging, and educational format. Each episode ends with an “Expert CardioNerd Perspectives & Review” (E-CPR) for a nuanced teaching from a content expert. We truly believe that hearing about a patient is the singular theme that unifies everyone at every level, from the student to the professor emeritus. We are teaming up with the ACC FIT Section to use the #CNCR episodes to showcase CV education across the country in the era of virtual recruitment. As part of the recruitment series, each episode features fellows from a given program discussing and teaching about an interesting case as well as sharing what makes their hearts flutter about their fellowship training. The case discussion is followed by both an E-CPR segment and a message from the program director. CardioNerds Case Reports PageCardioNerds Episode PageCardioNerds AcademySubscribe to our newsletter- The HeartbeatSupport our educational mission by becoming a Patron!Cardiology Programs Twitter Group created by Dr. Nosheen Reza Patient Summary A woman in her late 40s presented with a one day history of intermittent chest pain. EKG showed anteroseptal and lateral STE with reciprocal ST depressions in the inferior leads. High-sensitivity troponin was elevated at 333 ng/mL. Emergent LHC showed a long and narrow left main with areas of additional contrast filling into a false lumen with no flow in the LAD. RCA and LCx were normal appearing (make sure you check out the angiogram videos below!). IVUS showed dissection and heavy thrombus burden in the left main artery. Shortly after the diagnostic angiogram, the patient went into V-fib arrest and received one shock with ROSC. Amiodarone was started and an Impella CP was placed for additional left ventricular support. ECMO and emergent CABG were not readily available at this time so the interventional team attempted revascularization with PCI to the left main given patient's hemodynamic instability from ongoing ischemia. However, even after PCI to left main, flow to LAD remained poor and the LCx now also appeared occluded. The decision was made to cease further attempts at revascularization. Unfortunately, post-procedure TTE showed a reduced EF of 22% with anterior and anterolateral hypokinesis. She was transferred to CCU on maximal Impella support. Patient eventually developed acute renal and liver failure secondary to cardiogenic shock and suffered an additional V-fib arrest with ROSC. Eventually, Ronald Reagan UCLA was contacted for transfer and the mobile ECMO team was dispatched. They placed the patient on VA-ECMO in the outside facility and transferred her to Ronald Reagan UCLA. At Ronald Reagan, revascularization was attempted given persistent cardiogenic shock and 3 stents were successfully deployed in the LAD. She was eventually weaned off of both Impella and ECMO after successful PCIs to LAD. However, TTE showed persistently low EF and patient eventually underwent successful heart-kidney transplantation. Case Media ABCDClick to Enlarge A. ECG: Anterior STE, STE in I/aVL but depressedions in V4-V6, inferior reciprocal ST depressionB. X-ray of explanted heart shows stents extending from LM -> dLADC. Cross-section of explanted heart from apex to base showing infarct in the anteroseptal areaD. Histological cross section of the explanted LAD. This film shows slit like LM with no LAD. High OM/RI and LCx look ok. BMW wire used to cross distal LM into high OM/RIArrested after diagnostic, got ROSC and then Impella CP inserted L femoral Attempting wiring the true lumen, stuck in mLAD after 1st septal comes off IVUS from RI to LM. Shows dissection plane and lots of thrombusLM IVUS details: 4.57 x 5.0mm proximally, 4.52mm distally Unable to pass a wire into mid LAD PCI of LM: Synergy 4.0 x 16mm DES deployed in LM and post-dilated with Emerge NC 4.5 x 8mm balloon Flow remained poor at mLAD even after PCI to LM LCx system closed after LM PCI, so no further attempts TTE: Apical 4 Chamber TTE: Apical 2 Chamber TTE: Apical 3 Chamber LCx occluded with large OM1/Ramus still patent Post PCI of the LAD Episode Schematics & Teaching Click to enlarge! The CardioNerds 5! – 5 major takeaways from the #CNCR case What is SCAD and what population is most at risk? SCAD stands for spontaneous coronary artery dissection. It is an acute coronary event and is defined as a spontaneous separation of the coronary artery wall that is not iatrogenic or related to trauma. It is an important cause of acute myocardial infarction. Women comprise 87%-95% of SCAD patients with a mean age of presentation between 44-53 years, just like the patient in this case. The "typical" SCAD patient is a middle-aged female with few traditional cardiovascular risk factors such as hypertension, hyperlipidemia, and tobacco use. However, our understanding of a "typical" SCAD patient is limited as the majority of patients in large series have been white and it is likely that patients of different ethnic and racial backgrounds have been under-represented in most current registries. In some studies, the prevalence of SCAD appears around 4% of all patients presenting with ACS and up to 35% in women 50 years or under presenting with ACS. Pregnancy associated SCAD is an important subset of patients. It can occur at any time during the pregnancy or post-partum, with the majority of cases occurring postpartum. SCAD associated with pregnancy tends to have a more severe clinical presentation, including left main involvement, multi-vessel dissection and cardiogenic shock. Both pregnancy and non-pregnancy associated SCAD tend to occur more frequently in multiparous women and those that report a higher prevalence of pre-eclampsia. What are the two hypotheses that have been proposed to explain the pathophysiology of SCAD? Before reviewing the pathophysiology, let's briefly review the coronary arterial wall structure. The intima is the inner layer in contact with the intraluminal space. In normal vasculature, the intima is only a few cell layers thick and is separated from the media by the internal elastic lamina. The media is the middle layer and is made up of layers of smooth muscle cells which help regulate vascular tone. The media is separated from the adventitia by the external elastic lamina. Finally, the adventitia surrounds the media and through fibrous connective tissue provides support for the epicardial vessel. In SCAD, a hematoma forms within the tunica media separating the intima or intima/media from the vessel and compressing the true lumen leading to ischemia. There are several proposed hypotheses for how this occurs: "Inside-out" hypothesis: an endothelial-intimal disruption or "flap" develops first and then blood enters the sub-intimal space from the true lumen via this "flap" "Outside-in" hypothesis: a hematoma forms within the media, possibly from disruption of traversing micro-vessels, and compresses and occludes the true lumen as the hematoma expands. In both hypotheses, the end result is separation of the layers of coronary artery wall, creating a false vs. true lumen. Currently, the evidence favors the "outside-in" theory because in most SCAD cases, there are no communication between the true and false lumens observed. What are the angiographic appearances of SCAD? Left anterior descending artery is the most commonly affected vessel in SCAD. There are three classifications of SCAD based on angiographic appearance (the Yip-Saw classification). Type 1: Contrast dye staining of the arterial wall demonstrates double or multiple radiolucent lumens separated by a radiolucent flap. There may be dye "hang-up" or slow contrast clearing. Type 2: This is the most common subtype. It is characterized by long, diffuse, and smooth narrowing that can vary from mild stenosis to complete occlusion, often with abrupt changes in lumen diameter. Type 2a SCAD demonstrates normal arterial segments proximal and distal to a dissection and does not extend into a distal vessel. Type 2b does extend into the distal tip of a vessel. Type 3: The angiographic appearance mimics a focal stenosis of atherosclerotic disease and typically requires intracoronary imaging to make a definitive diagnosis. There are other angiographic findings that may clue the cardiology team into a diagnosis of SCAD. SCAD tends to affect more distal segments than atherosclerotic disease. Furthermore, the left anterior descending (LAD) artery is the most commonly affected vessel in SCAD. Patients with SCAD tend to have more tortuous vessels and atherosclerotic lesions are usually absent from vessels not affected by the SCAD. Some reports have indicated the external luminal compression by the intramural hematoma (IMH) gives the appearance of a stick insect. What is the management of SCAD in the acute setting? As Dr. Hayes et al. note in their JACC review,