Gender Differences and Predictors of Mortality in Spontaneous Coronary Artery Dissection: A Review of Reported Cases

Spontaneous coronary artery dissection (SCAD) is a rare but potentially lethal event.^1,2 It is a separation between the intimal and medial wall of the coronary vessel. The potential result of the dissection is obstruction of the vessel lumen and subsequent myocardial ischemia. Prior to the widespread use of coronary angiography, diagnosis was made at autopsy.² From reported cases, some trends have been identified. There are reported associations with female sex,^2,3 exercise,^4–7 pregnancy and postpartum state,^8–12 coronary artery disease,^{2, 13, 14} and connective tissue disorders.^9,15,16 The left anterior descending artery is more affected in women; the right coronary artery is more often affected in men.² Most cases have no identifiable risk factor.^17,18 There is little information on etiology, management and outcomes for SCAD. We report two patients with SCAD that highlight the uncertainties surrounding the treatment and diagnosis of this disease. Consequently, we undertook a comprehensive literature review to identify risk factors, treatment strategies and outcomes for this disorder. Methods. We reviewed the literature to gather all reported cases of SCAD. We searched Medline from 1966 through January 2000 for “spontaneous coronary dissection” and “coronary dissection.” Additionally, we reviewed the bibliography of each retrieved article to ensure that all referenced cases were obtained (n = 284). A total of 222 cases were found in the published literature with information concerning history, treatment and outcome. Cases in which complete data were not available were excluded (n = 60). Cases were classified as surviving (alive) if patients survived the initial event and were discharged; patients who were diagnosed at autopsy or died during hospitalization were classified together as dead. Univariate statistical analysis (chi-square or unpaired corrected t-test) was used to classify sex differences in those patients with SCAD. Logistic regression analysis was used to identify risk factors for mortality from SCAD. Case Report 1. A 43-year-old female presented complaining of 24 hours of continuous burning chest pain, radiating into the left arm, associated with dyspnea and diaphoresis. She had no prior medical problems. Cardiac risk factors included tobacco use, family history of premature coronary disease, and hypertension treated with combination losartan/hydrochlorothiazide. Past surgical history included total hysterectomy and salpingoopherectomy for bleeding at age 22 without subsequent estrogen replacement. An electrocardiogram revealed sinus rhythm and 3 mm ST-segment elevation in the inferior leads, consistent with an evolving acute inferior wall myocardial infarction. The patient was treated with tissue plasminogen activator, as well as standard therapy for myocardial infarction. Within one hour of receiving thrombolytics, her chest pain resolved and the ST-segment elevations returned to normal. She was admitted to the coronary care unit. A diagnostic cardiac catheterization was performed to define the coronary anatomy. The left coronary system revealed only luminal irregularities, while the right coronary artery views displayed a significant dissection in the mid-portion, from the acute marginal branch extending into the posterolateral branch (Figure 1). The ejection fraction was calculated at 52%. Continued medical therapy of coronary artery disease was recommended, which included aspirin, heparin, and beta-blockade. The patient remained stable on medical therapy with no recurrence of chest pain until the day following the procedure. She developed sudden onset of chest pain and quickly developed bradycardia and asystole. Attempts at resuscitation were unsuccessful. Autopsy revealed myocardial rupture as the cause of death. Case Report 2. A 47-year-old female presented to the emergency department with sudden onset of chest pain. Past medical history included hypertension treated with acebutolol, hypercholesterolemia treated with fluvastatin, and hypothyroidism treated with levothyroxine. Total creatine phosphokinase was 808, with elevated MB fraction. An electrocardiogram revealed sinus rhythm, with ST-elevation in the antero-lateral leads, depression in the inferior and lateral leads, and a nonspecific intraventricular conduction delay. She was treated with thrombolytics in the emergency department with resolution of chest pain and EKG changes. The patient was treated with standard medical therapy for coronary disease and had no complications. Catheterization on hospital day-four revealed spontaneous dissection of the first obtuse marginal. She had no other significant disease. Medical therapy was continued, and the patient was discharged in stable condition. Five years later the patient developed another episode of severe midsternal chest pain. An electrocardiogram revealed that she had ST-elevation in the anterior leads with intermittent left bundle branch block. Urgent coronary angiography revealed a dissection of the proximal left anterior descending artery. An attempt was made at percutaneous intervention, however, the lesion could not be crossed. An intra-aortic balloon pump was placed, and minimally invasive coronary bypass was performed emergently. The left internal mammary artery was used to bypass the distal left anterior descending artery. The patient tolerated the procedure well and had an uneventful recovery. She continues to do well after two years of follow-up. Results. Of 224 cases of SCAD with complete data, 161 (71.9%) were women and 63 (28.1%) were men (Table 1). The number of reported cases of SCAD increased over time. Mortality was 42.9% (n = 96) and improved over time (Figure 2). The majority of reported cases had no risk factor for SCAD identified (61.2%, n = 137). Of the risk factors identified, the most frequent were pregnancy or postpartum state, coronary artery disease, and exercise. Less common risk factors included Marfan’s syndrome (n = 2), hypersensitivity vasculitis (n = 1), oral contraceptives (n = 1), and hypertension (n = 3). Most patients received no treatment (62.5%, n = 140); however, by the last decade, 63.5% received some form of therapy. Operative repair was the most common therapeutic modality used (n = 40). More women died of SCAD than men (50.0 versus 24.6%; p

1. Basso C, Morgagni GL, Thiene G. Spontaneous coronary artery dissection: A neglected cause of acute myocardial ischaemia and sudden death. Heart 1996;75:451–454. 2. DeMaio SJ, Jr., Kinsella SH, Silverman ME. Clinical course and long-term prognosis of spontaneous coronary artery dissection. Am J Cardiol 1989;64:471–474. 3. Kearney P, Singh H, Hutter J, et al. Spontaneous coronary artery dissection: A report of three cases and review of the literature. Postgrad Med J 1993;69:940–945. 4. Thayer JO, Healy RW, Maggs PR. Spontaneous coronary artery dissection. Ann Thorac Surg 1987;44:97–102. 5. Almahmeed WA, Haykowski M, Boone J, et al. Spontaneous coronary artery dissection in young women. Cathet Cardiovasc Diagn 1996;37:201–205. 6. Sherrid MV, Mieres J, Mogtader A, et al. Onset during exercise of spontaneous coronary artery dissection and sudden death. Occurrence in a trained athlete: Case report and review of prior cases. Chest 1995;108:284–287. 7. Fronc HC, MacMillan RM, Kimbiris D. Coronary artery dissection – A case report. Angiology 1990;41:884–887. 8. Klutstein MW, Tzivoni D, Bitran D, et al. Treatment of spontaneous coronary artery dissection: Report of three cases. Cathet Cardiovasc Diagn 1997;40:372–376. 9. Engelman DT, Thayer J, Derossi J, et al. Pregnancy related coronary artery dissection: A case report and collective review. Conn Med 1993;57:135–139. 10. Elming H, Kober L. Spontaneous coronary artery dissection. Case report and literature review. Scand Cardiovasc J 1999;33:175–179. 11. Bac DJ, Lotgering FK, Verkaaik AP, Deckers JW. Spontaneous coronary artery dissection during pregnancy and postpartum. Eur Heart J 1995;16:136–138. 12. Wells AL. Dissecting aneurysm of coronary artery in the puerperium. J Pathol 1960;79:404–405. 13. Pasalodos PJ, Vazquez GN, Perez AL, et al. Spontaneous coronary artery dissection. Cathet Cardiovasc Diagn 1994;32:27–32. 14. Iskandrian AS, Bemis CE, Kimbiris D, et al. Primary coronary artery dissection. Chest 1985;87:227–228. 15. Ehya H, Weitzner S. Postpartum dissecting aneurysm of coronary arteries in a patient with sarcoidosis. South Med J 1980;73:87–88. 16. Bonnet J, Aumailley M, Thomas D, et al. Spontaneous coronary artery dissection: Case report and evidence for a defect in collagen metabolism. Eur Heart J 1986;7:904–909. 17. Jorgensen MB, Aharonian V, Mansukhani P, Mahrer PR. Spontaneous coronary dissection: A cluster of cases with this rare finding. Am Heart J 1994;127:1382–1387. 18. Mahenthiran J, Revankar R, Koka V, et al. Spontaneous coronary artery dissection presenting as acute myocardial infarction. J Natl Med Assoc 2000;92:87–90.