◆ 12/18/16 Disclosures Spontaneous Coronary Artery I have nothing to disclose Dissection Jeffrey Zimmet, MD, PhD Associate Professor of Medicine, UCSF Director, Cardiac Catheterization Laboratory, SFVAMC SCAD: Major points SCAD: Major Points ■ It’s not just related to pregnancy ■ Invasive coronary angiography is still the ■ It is an under-recognized cause of mainstay of diagnosis acute coronary syndrome ■ Intravascular imaging with ■ If you don’t suspect it, you can IVUS or OCT is an important easily miss it adjunct in equivocal cases ■ The “classic” angiographic ■ CT can be helpful but often appearance represents only a misses the diagnosis, fraction of cases – need to know especially in smaller vessels the alternative types ◆ 1
◆ 12/18/16 SCAD: Major points SCAD – What is it? ■ Many cardiologists won’t recognize ■ The non-traumatic and non-iatrogenic separation of the coronary arterial walls, the non-pathognomonic forms on creating a false lumen coronary angio ■ It is an under-recognized and often- ■ The principles of management are missed cause of acute coronary primarily a product of expert syndrome opinion ■ It is uncommon, but not as rare as once thought. Intimal tear vs Medial How does it occur? hemorrhage Two primary theories: ■ Intimal tear ◆ The primary event is a tear or rupture of the intima, allowing pressurized blood to enter the subintimal space ■ Medial hemorrhage ◆ The primary event is the rupture of vasa vasorum ◆ Leads to “classic” appearance ◆ 2
◆ 12/18/16 SCAD: Epidemiology Predisposing factors Female preponderance: recent series estimate 92- Strong association with fibromuscular dysplasia ■ ■ 95% of cases when atherosclerotic causes were (FMD) – present in >70% of SCAD patients who excluded are screened Association with pregnancy and the peripartum ■ period Recent series estimate that SCAD accounts for ■ between 1 and 4% of acute coronary syndromes Should be strongly considered in younger women ■ without CAD RFs presenting with ACS However, older women not excluded. In recent ■ case series, over half of patients were > 50 years old and 62% were post-menopausal SCAD - Precipitating Predisposing factors factors Intense emotional stress Pregnancy (once thought to comprise a large ■ ■ Weight lifting and isometric exercises proportion of cases; now ~5%) ■ Valsalva-like activities: childbirth, coughing, ■ vomiting, bowel movement Sympathomimetic drugs, including cocaine and Hormonal therapy ■ ■ methamphetamines Connective tissue disorders: ■ Note that the same stresses can precipitate classic ■ o Marfan syndrome atherosclerotic MI/plaque rupture o Loeys-Dietz syndrome o Ehler-Danlos syndrome o cystic medial necrosis o alpha-1 antitrypsin deficiency o polycystic kidney disease ◆ 3
◆ 12/18/16 Clinical Presentation Most present with chest pain and positive cardiac ■ enzymes (96% of the largest published series of 196 pts) Long period from symptom-onset to presentation is ■ the norm -- average of 1.1 days in the same series 1/3 of patients had unstable symptoms (ongoing ■ pain or stuttering/recurrent pain) prior to cardiac cath A significant proportion present as STEMI ■ A small proportion present with ventricular ■ arrhythmia, cardiogenic shock, or SCD Diagnosis by angiography Diagnosis by angiography ■ Type I: classic angiographic appearance (pathognomonic) of multiple lumens ■ Classification proposed by J Saw in Catheter Cardiovasc Interv in 2014 ◆ Type I: classic angiographic appearance (pathognomonic) of multiple lumens ◆ Type II: diffuse narrowing in the absence of atherosclerosis. Often long and smooth, affecting mid to distal segments of arteries ◆ Type III: mimicks atherosclerotic disease ◆ 4
◆ 12/18/16 ■ Type II: diffuse narrowing in the absence of ■ Type I: classic angiographic appearance atherosclerosis. Often long and smooth, (pathognomonic) of multiple lumens affecting mid to distal segments of arteries ◆ Saw J, et al J Am Coll Cardiol. 2016 Jul 19;68(3):297-312 ■ Type III: mimicks atherosclerotic disease Diagnosis by angiography Screening for renal and iliac FMD at the time of ■ coronary angiography may be useful, due to strong association of FMD with SCAD Acute plaque rupture (in arteriosclerotic coronary ■ disease) may appear angiographically identical ◆ 5
◆ 12/18/16 Diagnosis by OCT and IVUS Diagnosis by OCT and IVUS Definitive diagnosis of SCAD ■ Risks of placing wire in false lumen, or propagating ■ ◆ normal the dissection. ◆ dissection Diagnosis by OCT Diagnosis by OCT ◆ Antoniucci D, et al, Eur Heart 11(12):1130-1134. ◆ 6
◆ 12/18/16 Increased suspicion for SCAD Management SCAD in: Myocardial infarction in young women (especially ■ age ≤ 50) ■ All based on expert opinion from Absence of traditional cardiovascular risk factors case series ■ Little or no evidence of typical atherosclerotic ■ ■ No randomized trials lesions in coronary arteries Peripartum state ■ History of fibromuscular dysplasia ■ History of relevant connective tissue disorder or ■ systemic inflammatory condition (e.g. Marfan’s, SLE, cystic medial necrosis, etc, etc). Recent intensive exercise or emotional stress ■ SCAD Management – SCAD Management Antiplatelet therapy Beta blockers Reduction of false lumen thrombus burden ◆ Probably beneficial ■ Treatment of prothrombotic environment when ◆ Almost universally recommended ■ intimal tear is present (not all SCAD) ◆ Reduce shear stress ◆ Beneficial in tolerating ischemia Aspirin : generally considered important in both ◆ Reduce ventricular arrhythmia ■ short- and long-term treatment Clopidogrel : Controversial ■ ◆ Often given in combination with ASA for 1-12 months after presentation ◆ 7
◆ 12/18/16 SCAD – gpIIb/llla inhibitors Glycoprotein IIb/IIIa inhibitors (abciximab, ■ eptifibatide, tirofiban) ◆ generally not recommended . Greater propensity for bleeding, and potential to extend the dissection SCAD - Thrombolytics SCAD - Anticoagulants Generally considered to be contraindicated ■ Heparin/LMWH is generally given up to the ■ point of angiography for ACS management Multiple reports of clinical worsening, extension of ■ intramural hematoma and dissection ■ Risk of extending the dissection In one retrospective series of 87 patients with ■ Risk is balanced by potential benefit of ■ SCAD who received thrombolytics, 52 had clinical improving flow in the true lumen, and worsening improving compression by false lumen Multiple individual case reports of benefit of thrombus ■ thrombolytics, due to lysis of false lumen thrombi ■ Most recommend discontinuation of heparin and improvement in true lumen compression once the diagnosis is made; however, there is Balance of evidence suggests they should be ■ not general agreement on this point avoided ■ Contrast with carotid dissection ◆ 8
◆ 12/18/16 SCAD – adjunctive SCAD – adjunctive pharmacology pharmacology ■ Statins ■ ACE inhibitors ◆ No good data ◆ No data ◆ tend to be given post MI, regardless of etiology ◆ Generally given when there are other ◆ one small retrospective study suggested high rate of recurrence of SCAD with statin use indications, such as LV dysfunction or ◆ another study reported high statin use with low hypertension recurrence rate ◆ bottom line: give them to patients with hyperlipidemia. Use in others is just a guess SCAD – Conservative SCAD - Revascularization therapy Conservative therapy is generally recommended In published case series, patients who were initially ■ treated conservatively had a small likelihood of if possible progression requiring revascularization: 3.5% in Conservatively-treated patients often heal the Vancouver series, and 10% in the Mayo clinic ■ Multiple prospective series with planned repeat series. ■ angiography Most recurrence occurs in the first several days. ■ have demonstrated that spontaneous dissections most Patients treated conservatively should be ■ often heal with conservative management: 73% (43 of 59 monitored for 3-5 days in the hospital. cases); 90% (79 of 88); and 97% (29 of 30) almost all repeat imaging performed more than 1 month ■ after presentation shows healing, although multiple individual cases show residual dissection on repeat late angio ◆ 9
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