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Background: Spontaneous coronary artery dissection (SCAD) is an important cause of myocardial infarction (MI) in young to middle-aged women.Objectives: We aim to define the long-term natural history of SCAD.Methods: We performed a multicenter, prospective, observational study of patients with nonatherosclerotic SCAD presenting acutely from 22 North American centers. We recorded baseline demographics, in-hospital characteristics, precipitating and predisposing conditions, angiographic features (adjudicated), in-hospital and 3-year major adverse cardiovascular events (MACE). Cox regression multivariable analysis was performed.Results: We prospectively enrolled 750 consecutive patients with SCAD from June 2014 to June 2018. Mean age was 51.7 ± 10.5 years, 88.5% were women (55.0% postmenopausal); 31.3% presented with ST-segment elevation myocardial infarction, and 68.3% with non-ST-segment elevation myocardial infarction. Precipitating emotional stressor was reported in 50.3%, and physical stressor in 28.9%. Predisposing conditions included fibromuscular dysplasia in 42.9% (56.4% in those with complete screening), peripartum state 4.5%, and genetic disorders 1.6%. Most patients were treated conservatively (84.3%); 14.1% underwent percutaneous coronary intervention (PCI), 0.7% coronary artery bypass graft. At 3.0-year median follow-up, mortality was 0.8%, recurrent MI 9.9% (extension of previous SCAD 3.5%, de novo recurrent SCAD 2.4%, iatrogenic dissection 1.9%), with overall MACE 14.0%. Presence of genetic disorders, peripartum SCAD, and extracoronary fibromuscular dysplasia were independent predictors of 3-year MACE. Patients who underwent PCI at index hospitalization had similar postdischarge MACE compared with no PCI. At 3 years, 80.0% remained on aspirin and 73.5% on beta-blockade.Conclusions: Long-term mortality and de novo recurrent SCAD was low in our contemporary large SCAD cohort that included low revascularization rate and high use of beta-blockade and aspirin. Genetic disorders, extracoronary fibromuscular dysplasia, and peripartum SCAD were independent predictors of long-term MACE. [ABSTRACT FROM AUTHOR]

Spontaneous coronary artery dissection (SCAD) is an increasingly recognized cause of myocardial infarction (MI) that most frequently affects women. The characteristics of men with SCAD are less well described. The aim of this study was to describe the characteristics of men with SCAD. We compared baseline demographics, clinical presentation, angiographic findings and cardiovascular outcomes of men and women in the Canadian SCAD Study. Major adverse cardiovascular events (MACE) were composite of death, MI, stroke or transient ischemic attack, heart failure hospitalization, and revascularization. Of 1,173 patients with SCAD, 123 (10.5%) were men. Men with SCAD were younger than women (mean age 49.4 ± 9.6 years vs 52.0 ± 10.6 years; P = 0.01). Men had lower rate of prior MI than women (0.8% vs 7.0%; P = 0.005). Men were less likely to have fibromuscular dysplasia (FMD) (27.8% vs 52.7%; P = 0.001), depression (9.8% vs 20.2%; P = 0.005), emotional stress (35.0% vs 59.3%; P < 0.001), or high score on the Perceived Stress Scale (3.5% vs 11.0%; P = 0.025) but were more likely to report isometric physical stress (40.2% vs 24.0%; P = 0.007). There was no difference in angiographic types of SCAD, but men had more circumflex artery (44.4% vs 30.9%; P = 0.001) and fewer right coronary artery (11.8% vs 21.7%; P = 0.0054) dissections. At median follow-up of 3.0 (IQR: 2.0-3.8) years, men had fewer hospital presentations with chest pain (10.6% vs 24.8%; P < 0.001). There were no differences in in-hospital events or follow-up MACE (7.3% vs 12.7%; P = 0.106). Ten percent of SCAD patients were men. Men were younger and more likely to have a physical trigger but were less likely to have FMD, depression, or an emotional trigger. Men had less recurrent chest pain but no significant difference in MACE. [Display omitted] [ABSTRACT FROM AUTHOR]

Background: Spontaneous coronary artery dissection (SCAD) is an important cause of myocardial infarction (MI) in young to middle-age women. Ventricular tachycardia/ventricular fibrillation (VT/VF) may complicate acute SCAD presentations, and the long-term outcomes are unknown.Objective: The purpose of this study was to report the outcomes of SCAD patients presenting with VT/VF.Methods: We analyzed our prospective Canadian SCAD registries for patients presenting with VT/VF during index hospitalization. Long-term outcomes including VT/VF and cardiac arrest were collected. Univariate and multivariable analyses were performed to identify predictors of VT/VF at follow-up.Results: Among 1056 consecutive SCAD patients, 84 (8.0%) presented with VT/VF, and 8 underwent implantable cardioverter-defibrillator (ICD) insertion. Patients with VT/VF during index hospitalization were younger (49.3 vs 52.0 years; P = .019) and were more likely to have ST-elevation MI, lower left ventricular ejection fraction (LVEF), and left main dissection (all P <.001). Initial VT/VF was associated with in-hospital events, including recurrent MI, unplanned revascularization, heart failure, ICD insertion, and in-hospital death (all P <.05). At mean follow-up of 4.8 ± 3.3 years, 8 patients suffered VT/VF (time to event 5.2 ± 6.2 years); 5 of 8 patients had VT/VF on initial SCAD presentation, and 1 of 8 had undergone ICD insertion. Predictors of VT/VF during follow-up included LVEF <50%, LVEF <35%, peripartum SCAD, unplanned revascularization, repeat MI, heart failure, and initial VT/VF. Multivariable analysis showed initial VT/VF (odds ratio [OR] 9.5; 95% confidence interval [CI] 2.0-44; P = .004) and LVEF <50% (OR 12.9; 95% CI 1.5-111; P = .019) were independent predictors of VT/VF at follow-up.Conclusion: SCAD patients presenting with VT/VF were at greater risk for in-hospital events and recurrent VF/VT at follow-up. Both VT/VF and LVEF <50% were independent predictors of subsequent VT/VF. [ABSTRACT FROM AUTHOR]

Abstract Objectives Given the uncertainty regarding the degree and prevalence of spontaneous healing following spontaneous coronary artery dissection (SCAD), the aim of this study was to assess the angiographic characteristics of the dissected segments in a large cohort of patients with SCAD who underwent subsequent repeat coronary angiography. Background SCAD is an uncommon yet important cause of myocardial infarction in women. Very little is known about the characteristics of healing of dissected arteries. Methods Patients with nonatherosclerotic SCAD followed prospectively at Vancouver General Hospital who underwent repeat angiography were included in this study. Those who underwent percutaneous coronary intervention for SCAD were excluded. Baseline patient demographics and in-hospital and long-term cardiovascular events were recorded. Angiographic characteristics of the SCAD artery at index and repeat angiography were assessed by 2 experienced angiographers. Criteria for angiographic healing were as follows: 1) improvement of stenosis severity from index event; 2) residual stenosis <50%; and 3) TIMI (Thrombolysis In Myocardial Infarction) flow grade 3. Results One hundred fifty-six patients with 182 noncontiguous SCAD lesions were included. The mean age was 51.5 ± 8.7 years, 88.5% were women, 83.3% were Caucasian, and 75.6% had fibromuscular dysplasia. All patients presented with myocardial infarction. At index angiography, type 2 SCAD was most commonly observed, in 126 of 182 lesions (69.2%); TIMI flow grade <3 was present in 85 of 182 (46.7%); and median lesion stenosis was 79.0% (interquartile range: 56.0% to 100%). Median time to repeat angiography was 154 days (interquartile range: 70 to 604 days), with median residual lesion stenosis improving to 25.5% (interquartile range: 12.0 to 38.8 days), and TIMI flow grade <3 observed in 10 of 182 lesions (5.5%). Angiographic healing occurred in 157 of 182 lesions (86.3%). Of repeat angiography performed ≥30 days post-SCAD, 152 of 160 (95%) showed spontaneous angiographic healing. Conclusions The majority of coronary arteries affected by SCAD heal spontaneously on repeat angiography, with apparent time dependency, with the vast majority having complete healing after 30 days from the SCAD event. Central Illustration [ABSTRACT FROM AUTHOR]

Myocardial CT perfusion imaging with dual energy (DE-CTP) can produce myocardial iodine perfusion maps. This study evaluated the accuracy of first pass myocardial iodine concentration in DE-CTP compared to CT derived dynamic myocardial blood flow (MBF) to determine regional myocardial ischemia in an animal model of coronary stenosis using invasive Fractional Flow Reserve (FFR). Seven anaesthetised pigs (mean weight 51 ± 4 kg) had a graded coronary artery stenosis produced in six vessels (plus one control animal) using a methacrylate plug with FFR recorded in the target artery (ischemia = FFR<0.80). During adenosine vasodilation, dynamic myocardial CTP and DE-CTP imaging was performed. Using vendor supplied applications, matching regions of interest (ROIs) were drawn in myocardial segments supplied by the target coronary artery to compare the two techniques. FFR correlated strongly to MBF (r = 0.81) and modestly to myocardial iodine concentration (r = 0.65) and myocardial CT attenuation (r = 0.62) (p < 0.0001 each). The correlation to FFR was stronger using relative ratios (absolute value/reference value of normal segments) than absolute values for MBF (r = 0.86), myocardial iodine concentration (r = 0.80) and CT number (r = 0.79) (p < 0.0001 each). Comparing normal and ischaemic territories there were significant differences in MBF (96 ± 14 vs. 27 ± 18 ml/100 ml of tissue/min, p < 0.0001), myocardial iodine concentration (3.5 ± 1 vs. 1.0 ± 0.7 mg/ml, p < 0.0001) and myocardial CT number (89 ± 9 vs. 73 ± 14 HU, p = 0.002). Myocardial iodine concentration had 91% sensitivity and 98% specificity for detecting FFR <0.8. Quantified myocardial iodine content from first pass DE-CTP correlates with CT derived myocardial blood flow and FFR and accurately discriminates ischemic territories in a porcine model. The accuracy and utility of myocardial iodine content in DE-CTP warrants further investigation in a clinical population with FFR as a reference standard. In this study a porcine model of coronary artery disease with invasive fractional flow reserve was used to validate myocardial iodine content derived from dual energy imaging to other measures of myocardial perfusion including dynamic myocardial CT perfusion. FFR correlated strongly to MBF and modestly to myocardial iodine concentration and myocardial CT number. Myocardial iodine content was significantly different in normal and ischemic territories. [ABSTRACT FROM AUTHOR]

Objectives: We sought to evaluate the prevalence of fibromuscular dysplasia (FMD) and other predisposing conditions among spontaneous coronary artery dissection (SCAD) patients. Background: Spontaneous coronary artery dissection is considered rare. However, we observed many young women with SCAD and concomitant FMD. Methods: Spontaneous coronary artery dissection patients were identified prospectively and retrospectively at Vancouver General Hospital over the past 6 years. Coronary angiograms were meticulously reviewed by 2 senior interventional cardiologists. Identified patients were contacted for prospective evaluation at our SCAD clinic, and screening for FMD of renal, iliac, and cerebrovascular arteries was performed with computed tomography angiography or magnetic resonance angiography, if not already screened during the index angiogram. Potential predisposing and precipitating conditions for SCAD were extracted from clinical history. Results: We identified 50 patients with nonatherosclerotic SCAD from April 2006 to March 2012. Average age was 51.0 years, and almost all were women (98.0%). All presented with myocardial infarction (MI), 30.0% had ST-segment elevation, and 70.0% had non–ST-segment elevation MI. Only 1 was postpartum, and 2 were involved in intense isometric exercises. Emotional stress was reported in 26.0% before the MI. Twelve percent had >1 dissected coronary artery. Most SCAD patients had FMD of ≥1 noncoronary territory (86.0%): 25 of 43 (58.1%) renal, 21 of 43 (48.8%) iliac, and 20 of 43 (46.5%) cerebrovascular (6 of 43, 14.0% had intracranial aneurysm). Five had incomplete FMD screening. Conclusions: Nonatherosclerotic SCAD predominantly affects women, and most have concomitant FMD. We suspect these patients have underlying coronary FMD that predisposed them to SCAD, but this requires proof from histology or intracoronary imaging of the affected coronary arteries. [ABSTRACT FROM AUTHOR]

Objectives: The purpose of this study was to evaluate the effects of aspirin and clopidogrel response on myonecrosis after percutaneous coronary intervention (PCI) with glycoprotein (GP) IIb/IIIa blockade. Background: Aspirin and clopidogrel resistance is increasingly recognized, but its effects on PCI outcomes with GP IIb/IIIa blockade are unknown. Methods: This was a prospective, pre-specified substudy of the BRIEF-PCI (Brief Infusion of Intravenous Eptifibatide Following Successful Percutaneous Coronary Intervention) trial, which randomized 624 patients to 18-h or <2-h eptifibatide infusion after uncomplicated PCI. To be eligible, patients must have been pre-treated with aspirin (≥5 days) and clopidogrel (75 mg/day ≥5 days, 300 mg loading ≥6 h, or 600 mg loading ≥2 h) and must not have received GP IIb/IIIa inhibitors within 48 h. Verify-Now Aspirin and Clopidogrel (P2Y12) assays were performed at baseline before PCI. Patients with aspirin reaction unit (ARU) ≥550 were labeled as aspirin resistant. Clopidogrel low-responders were defined as those in the lowest quartile of platelet inhibition. The primary end point was the prevalence of myonecrosis within 24 h after PCI. Results: We enrolled 209 patients into our substudy, of which 185 had aspirin response assessed, 198 had clopidogrel response assessed, and 174 had both assessed. There were 4.9% who were aspirin resistant. Clopidogrel low-responders were defined as those in the lowest quartile with platelet inhibition <19%. Only 1.1% had both aspirin resistance and low clopidogrel response. There was no difference in myonecrosis prevalence among aspirin-resistant compared with aspirin-sensitive patients (11.1% vs. 27.8%, p = 0.259) or among clopidogrel low-responders compared with clopidogrel responders (23.5% vs. 29.3%, p = 0.433). Conclusions: Aspirin and clopidogrel response did not affect myonecrosis prevalence amongst patients who received eptifibatide for PCI. [Copyright &y& Elsevier]

Objectives: The purpose of this study was to assess whether the early discontinuation of eptifibatide infusion in nonemergent percutaneous coronary intervention (PCI) is associated with a higher frequency of periprocedural ischemic myonecrosis. Background: The recommended regimen for eptifibatide is a double bolus followed by an infusion for 18 h. It is not known whether the infusion can be shortened if the PCI is uncomplicated. Methods: We enrolled 624 patients with stable angina, acute coronary syndrome, or recent ST-segment elevation myocardial infarction (>48 h) who underwent successful coronary stenting and received eptifibatide. Patients were randomly assigned to receive either an 18-h infusion or an abbreviated infusion of <2 h. The primary end point was the incidence of periprocedural myonecrosis defined as troponin-I elevation >0.26 μg/l. Secondary end points included death, myocardial infarction, urgent target vessel revascularization at 30 days, and in-hospital major bleeding using the REPLACE-2 (Randomized Evaluation in PCI Linking Angiomax to Reduced Clinical Events) trial criteria. Results: The incidence of periprocedural myonecrosis was 30.1% in the <2-h group versus 28.3% in the 18-h group (mean difference: 1.8%; upper bound of 95% confidence interval: 7.8%; p < 0.012 for noninferiority). The 30-day incidence of myocardial infarction, death, and target vessel revascularization was similar in both groups (p = NS). Major bleeding was less frequent in the <2-h group (1.0% vs. 4.2%, p = 0.02). Conclusions: After uncomplicated PCI, eptifibatide infusion can be abbreviated safely to <2 h. It is not inferior to the standard 18-h infusion in preventing ischemic outcome, and it may be associated with less major bleeding. (Brief Infusion of Eptifibatide Following Percutaneous Coronary Intervention [BRIEF PCI]; NCT00111566) [Copyright &y& Elsevier]

Spontaneous Coronary Artery Dissection and Cardiogenic Shock: Incidence, Etiology, Management, and Outcomes. [Extracted from the article]

Background: Spontaneous coronary artery dissection (SCAD) is underdiagnosed and an important cause of myocardial infarction (MI), especially in young women. Long-term cardiovascular outcomes, including recurrent SCAD, are inadequately reported.Objectives: This study sought to describe the acute and long-term cardiovascular outcomes and assess the predictors of recurrent SCAD.Methods: Nonatherosclerotic SCAD patients were prospectively followed at Vancouver General Hospital systematically to ascertain baseline, predisposing and precipitating stressors, angiographic features, revascularization, use of medication, and in-hospital and long-term cardiovascular events. Clinical predictors for recurrent de novo SCAD were tested using univariate and multivariate Cox regression models.Results: The authors prospectively followed 327 SCAD patients. Average age was 52.5 ± 9.6 years, and 90.5% were women (56.9% postmenopausal). All presented with MI; 25.7% had ST-segment elevation MI, 74.3% had non-ST-segment elevation MI, and 8.9% had ventricular tachycardia/ventricular fibrillation. Precipitating emotional stressors were reported in 48.3% and physical stressors in 28.1%. Fibromuscular dysplasia was present in 62.7%, connective tissue disorder in 4.9%, and systemic inflammatory disease in 11.9%. The majority (83.1%) were initially treated medically, with only 16.5% or 2.2% undergoing in-hospital percutaneous coronary intervention or coronary artery bypass graft surgery, respectively. The majority of SCAD patients were taking aspirin and beta-blocker therapy at discharge and at follow-up. Median hospital stay was 3.0 days, and the overall major adverse event rate was 7.3%. Median long-term follow-up was 3.1 years, and overall major adverse cardiac event rate was 19.9% (death rate: 1.2%; recurrent MI: 16.8%; stroke/transient ischemic attack: 1.2%; revascularization: 5.8%). Recurrent SCAD occurred in 10.4% of patients. In multivariate modeling, only hypertension increased (hazard ratio: 2.46; p = 0.011) and beta-blocker use diminished (hazard ratio: 0.36; p = 0.004) recurrent SCAD.Conclusions: In our large prospectively followed SCAD cohort, long-term cardiovascular events were common. Hypertension increased the risk of recurrent SCAD, whereas beta-blocker therapy appeared to be protective. [ABSTRACT FROM AUTHOR]

Background: Stent thrombosis (ST) is rare, but is associated with significant morbidity and mortality. Methods: We analyzed data from the British Columbia (BC) Registry from April 2011-January 2012. Results: 101 ST cases were reported and verified. Based on timing, ST was considered early (≤30days) in 35.6%, late (>30days-1year) in 17.8% and very late (>1year) in 46.5%. The majority (68.5%) presented with STEMI, and the remaining with non-STEMI (31.5%). Most vessels were functionally occluded (TIM1 flow grade ≤1 in 67.1%). Thrombus burden was high (TIMI thrombus grade ≥4 in 77.2%). Aspiration thrombectomy was performed in 41% of cases. New stents were implanted in 62.4% cases. Intra-coronary imaging was low (11%). At the original stent implantation, STEMI was the clinical presentation in 39.6%, the lesion was complex in 62.1%, and thrombus was visualized in 23.0%. Prognosis after ST was unfavorable with high mortality (11.9% at 30days and 16.8% at one year), and further revascularization (5.0% repeat PCI and 6.9% coronary artery bypass graft surgery). Early ST was associated with worse clinical outcome compared to late/very late ST: 30-day mortality at 22.2% versus 6.2% (p=0.02), and 1-year mortality at 27.8% versus 10.8% (p=0.05). Conclusions: In this prospective registry from BC, all ST presented with myocardial infarction, and the majority was treated with emergency PCI. Additional stents were commonly implanted with infrequent use of intracoronary imaging. Mortality rate was higher for early ST in comparison with late/very late ST. A comprehensive approach should be developed to treat this difficult complication. [ABSTRACT FROM AUTHOR]