Rosanna Tavella

Systematic Review of Patients Presenting With Suspected Myocardial Infarction and Nonobstructive Coronary Arteries

Background— Myocardial infarction with nonobstructive coronary arteries (MINOCA) is a puzzling clinical entity with no previous evaluation of the literature. This systematic review aims to (1) quantify the prevalence, risk factors, and 12-month prognosis in patients with MINOCA, and (2) evaluate potential pathophysiological mechanisms underlying this disorder. Methods and Results— Quantitative assessment of 28 publications using a meta-analytic approach evaluated the prevalence, clinical features, and prognosis of MINOCA. The prevalence of MINOCA was 6% [95% confidence interval, 5%–7%] with a median patient age of 55 years (95% confidence interval, 51–59 years) and 40% women. However, in comparison with those with myocardial infarction associated with obstructive coronary artery disease, the patients with MINOCA were more likely to be younger and female but less likely to have hyperlipidemia, although other cardiovascular risk factors were similar. All-cause mortality at 12 months was lower in MINOCA (4.7%; 95% confidence interval, 2.6%–6.9%) compared with myocardial infarction associated with obstructive coronary artery disease (6.7%, 95% confidence interval, 4.3%–9.0%). Qualitative assessment of 46 publications evaluating the underlying pathophysiology responsible for MINOCA revealed the presence of a typical myocardial infarct on cardiac magnetic resonance imaging in only 24% of patients, with myocarditis occurring in 33% and no significant abnormality in 26%. Coronary artery spasm was inducible in 27% of MINOCA patients, and thrombophilia disorders were detected in 14%. Conclusions— MINOCA should be considered as a working diagnosis with multiple potential causes that require evaluation so that directed therapies may improve its guarded prognosis.

Acute coronary syndrome care across Australia and New Zealand: the SNAPSHOT ACS study.

Objectives: To characterise management of suspected acute coronary syndrome (ACS) in Australia and New Zealand, and to assess the application of recommended therapies according to published guidelines.

Early use of N-acetylcysteine with nitrate therapy in patients undergoing primary percutaneous coronary intervention for ST-segment-elevation myocardial infarction reduces myocardial infarct size (the NACIAM trial [N-acetylcysteine in acute myocardial infarction])

Background: Contemporary ST-segment–elevation myocardial infarction management involves primary percutaneous coronary intervention, with ongoing studies focusing on infarct size reduction using ancillary therapies. N-acetylcysteine (NAC) is an antioxidant with reactive oxygen species scavenging properties that also potentiates the effects of nitroglycerin and thus represents a potentially beneficial ancillary therapy in primary percutaneous coronary intervention. The NACIAM trial (N-acetylcysteine in Acute Myocardial Infarction) examined the effects of NAC on infarct size in patients with ST-segment–elevation myocardial infarction undergoing percutaneous coronary intervention. Methods: This randomized, double-blind, placebo-controlled, multicenter study evaluated the effects of intravenous high-dose NAC (29 g over 2 days) with background low-dose nitroglycerin (7.2 mg over 2 days) on early cardiac magnetic resonance imaging–assessed infarct size. Secondary end points included cardiac magnetic resonance–determined myocardial salvage and creatine kinase kinetics. Results: Of 112 randomized patients with ST-segment–elevation myocardial infarction, 75 (37 in NAC group, 38 in placebo group) underwent early cardiac magnetic resonance imaging. Median duration of ischemia pretreatment was 2.4 hours. With background nitroglycerin infusion administered to all patients, those randomized to NAC exhibited an absolute 5.5% reduction in cardiac magnetic resonance–assessed infarct size relative to placebo (median, 11.0%; [interquartile range 4.1, 16.3] versus 16.5%; [interquartile range 10.7, 24.2]; P=0.02). Myocardial salvage was approximately doubled in the NAC group (60%; interquartile range, 37–79) compared with placebo (27%; interquartile range, 14–42; P<0.01) and median creatine kinase areas under the curve were 22 000 and 38 000 IU·h in the NAC and placebo groups, respectively (P=0.08). Conclusions: High-dose intravenous NAC administered with low-dose intravenous nitroglycerin is associated with reduced infarct size in patients with ST-segment–elevation myocardial infarction undergoing percutaneous coronary intervention. A larger study is required to assess the impact of this therapy on clinical cardiac outcomes. Clinical Trial Registration: Australian New Zealand Clinical Trials Registry. URL: http://www.anzctr.org.au/. Unique identifier: 12610000280000.

The What, When, Who, Why, How and Where of Myocardial Infarction With Non-Obstructive Coronary Arteries (MINOCA)

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is an intriguing clinical entity that is being increasingly recognized with the more common use of coronary angiography during acute myocardial infarction. This review systematically addresses the contemporary understanding of MINOCA, including, (1) what are the diagnostic criteria, (2) when the diagnosis should be considered, (3) who is at risk, (4) why this new syndrome should be diagnosed, (5) how these patients should be managed, and (6) where to next?

Impact of a regionalised clinical cardiac support network on mortality among rural patients with myocardial infarction.

Objective: To evaluate the impact of the regionalised Integrated Cardiovascular Clinical Network (ICCNet) on 30‐day mortality among patients with myocardial infarction (MI) in an Australian rural setting.

Myocardial Infarction With Nonobstructive Coronary Arteries (MINOCA): The Past, Present, and Future Management

Article, see p 1481 Myocardial infarction with nonobstructive coronary arteries (MINOCA) is clinically defined by the presence of the universal acute myocardial infarction (AMI) criteria, absence of obstructive coronary artery disease (≥50% stenosis), and no overt cause for the clinical presentation at the time of angiography (eg, classic features for takotsubo cardiomyopathy).1 With the more frequent contemporary use of coronary angiography in AMI, clinicians have been regularly confronted with this puzzling problem and seeking guidance in its management. An article by Lindahl et al2 in this issue of Circulation represents a major step forward in MINOCA and thereby warrants taking stock of the past, present, and future management strategies of this intriguing condition. The pioneering early angiography studies of DeWood et al demonstrated that ST-segment–elevation myocardial infarction was often associated with an occluded epicardial artery, but this occurred less frequently in non–ST-segment–elevation myocardial infarction, although in both conditions obstructive coronary artery disease was evident in >95% of patients.3 These findings underscored the importance of the underlying atherothrombotic process and provided the impetus for major advances in AMI management over the next 35 years. However, when angiography failed to reveal the presence of obstructive atheroma or thrombosis in patients with clinical criteria for ST-segment–elevation myocardial infarction, some clinicians labeled these patients as having a false-positive ST-segment–elevation myocardial infarction diagnosis.4 Such a label implies that an AMI has not occurred (despite the clinical presentation) and therefore no further diagnostic investigation or cardiac therapy is required. To avoid such diagnostic complacency, the diagnosis of MINOCA was coined5 with an emphasis on investigating these patients to identify the underlying cause of their AMI presentation. Providing a label for this clinical syndrome was the first …

Quality of Life of Patients With Peripheral Arterial Disease and Chronic Stable Angina

The Coronary Artery Disease in gENeral practiCE (CADENCE) study examined chronic stable angina (CSA). This further analysis examined atherosclerotic risk factors, symptomatic status, clinical management, and quality of life in patients with CSA with and without peripheral arterial disease (PAD). The CADENCE study involved 207 Australian general practitioners (GPs) recruiting 10 to 15 consecutively presenting patients with CSA (n = 2031). General practitioners completed a 2-page case report form, detailing demographic data, cardiovascular status, risk factors, and GP perception of control. Patients completed the Seattle Angina Questionnaire. Patients with coexisting CSA and PAD (17%) were more likely to be older and had more comorbidities than patients with CSA without coexisting PAD. Patients with peripheral arterial disease had a longer history of heart disease and were more likely to experience angina on a weekly basis. Patients with peripheral arterial disease had poorer quality-of-life indices.

Gender Differences in Patients with Stable Angina attending Primary Care Practices

OBJECTIVE The primary objective of this study was to assess gender differences in the health status of patients with chronic stable angina using the Seattle Angina Questionnaire (SAQ). Potential contributing clinical factors were also examined. METHODS Gender disparities in 2005 stable angina patients (712 females) were determined from general practitioner clinical evaluations and patient-completed questionnaire (SAQ). As there were significant age differences between genders, all subsequent analyses were adjusted for age. RESULTS Compared with men, women with angina had poorer angina-related health outcomes as assessed by the SAQ, including more frequent angina (81±22 vs 85±22, respectively, p<0.001) with greater associated physical limitations (65±27 vs 73±26, respectively, p<0.001) and a poorer quality of life (68±24 vs 71±24, respectively, p=0.0026). CONCLUSION Women with stable angina have poorer angina-related health outcomes compared with their male counterparts. Multiple factors may contribute to this disparity including differences in clinical factors, underlying biological mechanisms and psychosocial factors.

Disparities in acute in-hospital cardiovascular care for Aboriginal and non-Aboriginal South Australians.

Objectives: To assess differences in the rates of angiography and subsequent revascularisation for Aboriginal and non‐Aboriginal South Australians who presented with an acute coronary syndrome (ACS); to explore the reasons for any observed differences.

Epidemiology of Coronary Artery Disease

Epidemiology involves the study of the frequency, distribution, and impact of diseases within a community in order to address potential prevention or treatment of these conditions. Accordingly, evaluating the epidemiology of coronary artery disease (CAD) constitutes a particularly wide spectrum that cannot be comprehensively covered in a solitary book chapter. Consequently this first section will provide an introductory broad overview of CAD including pathophysiological concepts, clinical manifestations, geographic variations and its impact on patient health. After defining the broader context of this large field, the specific scope of chapter will be outlined.