Canadian Spontaneous Coronary Artery Dissection Cohort Study: 3-Year Outcomes.

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.

Canadian spontaneous coronary artery dissection cohort study: in-hospital and 30-day outcomes.

AIMS: Spontaneous coronary artery dissection (SCAD) was underdiagnosed and poorly understood for decades. It is increasingly recognized as an important cause of myocardial infarction (MI) in women. We aimed to assess the natural history of SCAD, which has not been adequately explored. METHODS AND RESULTS: We performed a multicentre, prospective, observational study of patients with non-atherosclerotic SCAD presenting acutely from 22 centres in North America. Institutional ethics approval and patient consents were obtained. We recorded baseline demographics, in-hospital characteristics, precipitating/predisposing conditions, angiographic features (assessed by core laboratory), in-hospital major adverse events (MAE), and 30-day major adverse cardiovascular events (MACE). We prospectively enrolled 750 SCAD patients from June 2014 to June 2018. Mean age was 51.8 ± 10.2 years, 88.5% were women (55.0% postmenopausal), 87.7% were Caucasian, and 33.9% had no cardiac risk factors. Emotional stress was reported in 50.3%, and physical stress in 28.9% (9.8% lifting >50 pounds). Predisposing conditions included fibromuscular dysplasia 31.1% (45.2% had no/incomplete screening), systemic inflammatory diseases 4.7%, peripartum 4.5%, and connective tissue disorders 3.6%. Most were treated conservatively (84.3%), but 14.1% underwent percutaneous coronary intervention and 0.7% coronary artery bypass surgery. In-hospital composite MAE was 8.8%; peripartum SCAD patients had higher in-hospital MAE (20.6% vs. 8.2%, P = 0.023). Overall 30-day MACE was 8.8%. Peripartum SCAD and connective tissue disease were independent predictors of 30-day MACE. CONCLUSION: Spontaneous coronary artery dissection predominantly affects women and presents with MI. Despite majority of patients being treated conservatively, survival was good. However, significant cardiovascular complications occurred within 30 days. Long-term follow-up and further investigations on management are warranted.

2010 Canadian Cardiovascular Society/Canadian Association of Interventional Cardiologists Guidelines for Training and Maintenance of Competency in Adult Interventional Cardiology.

Interventional cardiology is a subspecialty of adult cardiology dedicated to the use and application of imaging-based diagnostic techniques and minimally invasive modalities for the treatment of cardiovascular disease. Currently, interventional cardiologists must demonstrate expert knowledge of cardiac imaging, along with cardiovascular anatomy and the pathophysiology of cardiovascular disease. In addition, they must possess the technical skills required for the practice of interventional cardiology and be knowledgeable about new antiplatelet and antithrombotic drugs mandated for optimal patient care. The 2010 Canadian Cardiovascular Society/Canadian Association of Interventional Cardiologists Guidelines for Training and Maintenance of Competency in Adult Interventional Cardiology are the first such guidelines to be published in Canada. These guidelines should allow for more-fluid provision of high-quality interventional cardiology education, along with less geographic variation, resulting in more-widespread high-level services to the population.

A prospective randomized comparison of loop recorders versus Holter monitors in patients with syncope or presyncope.

BACKGROUND: The initial management of syncope or presyncope typically involves short-term cardiac monitoring using a Holter monitor. A loop recorder is used to extend the period of monitoring to increase the probability of obtaining a symptom-rhythm correlation. Loop recorders and Holter monitors are both used commonly, but their utility has not been compared prospectively. METHODS: Patients with syncope or presyncope referred for a Holter monitor or a loop recorder were assigned randomly to receive either a 48-hour Holter monitor or a loop recorder for 1 month as an initial diagnostic strategy. If the initial strategy was unsuccessful, patients were offered crossover to the alternate strategy. RESULTS: One hundred patients (mean [+/- SD] age, 56 +/- 20 years; 44 women) with syncope (n = 21), presyncope (n = 29), or both (n = 50) were enrolled. Of the 49 patients assigned randomly to an external loop recorder first, 31 (63%) had an arrhythmia identified or excluded, versus 12 (24%) of 51 patients assigned to a Holter monitor initially (P <0.0001). Arrhythmia was identified as a cause of syncope in 1 patient with a loop recorder, compared with no patients with a Holter monitor (P = 0.31). Of the 29 patients with negative results with Holter monitoring who went on to receive a loop recorder, 13 (45%) had arrhythmia excluded, compared with none of the 4 patients who crossed over to receive a Holter monitor. The overall probability of obtaining a symptom-rhythm correlation was 56% (44/78) for loop recorders versus 22% (12/55) for Holter monitors (P <0.0001). Despite patient education and test transmissions, 13 (23%) of 57 patients who had recurrence of their symptoms failed to activate their loop recorder properly. CONCLUSION: Loop recorders have a much higher diagnostic yield for patients with syncope or presyncope as compared with Holter monitors. The utility of loop recorders is limited by some patients' inability to operate them correctly.