Chest pain in patients with 'normal angiography': could it be cardiac?

Diagnostic Puzzles and Cause-Targeted Treatment Strategies in Myocardial Infarction with Non-Obstructive Coronary Arteries: An Updated Review

Myocardial infarction with nonobstructive coronary arteries (MINOCA) is a distinct subtype of myocardial infarction (MI), occurring in about 8-10% of spontaneous MI cases referred for coronary angiography. Unlike MI with obstructive coronary artery disease, MINOCA's pathogenesis is more intricate and heterogeneous, involving mechanisms such as coronary thromboembolism, coronary vasospasm, microvascular dysfunction, dissection, or plaque rupture. Diagnosing MINOCA presents challenges and includes invasive and non-invasive strategies aiming to differentiate it from alternative diagnoses and confirm the criteria of elevated cardiac biomarkers, non-obstructive coronary arteries, and the absence of alternate explanations for the acute presentation. Tailored management strategies for MINOCA hinge on identifying the underlying cause of the infarction, necessitating systematic diagnostic approaches. Furthermore, determining the optimal post-MINOCA medication regimen remains uncertain. This review aims to comprehensively address the current state of knowledge, encompassing diagnostic and therapeutic approaches, in the context of MINOCA while also highlighting the evolving landscape and future directions for advancing our understanding and management of this intricate myocardial infarction subtype.

The Association of Obstructive Sleep Apnea in Ischemia with No Obstructive Coronary Artery Disease - A Pilot Study

Obstructive sleep apnea (OSA) is increasingly recognized to be a risk factor for cardiovascular disease. This pilot study assessed the association of OSA and invasive coronary microvascular function in patients with ischemia with no obstructive coronary artery disease (INOCA). Forty-two patients with angina, were prospectively screened at a single tertiary centre covering the northern metropolitan area of South Australia, from February 2018 to December 2020 (ACTRN12618000149268). Forty patients were invited into to this observational study after coronary angiography demonstrated INOCA and functional coronary vasomotor disorder (n = 40). Twenty one participants subsequently underwent a sleep study for OSA diagnosis while 9 participants had prior formal diagnosis of OSA (ACTRN12618000227291). Of the 30 participants with OSA data, 87% (n = 26) had a diagnosis of OSA. Accordingly, 11 with mild severity, 7 with moderate severity and 8 with severe OSA. No OSA was observed in 4 participants. Participants with OSA were older [61.4±8.7 vs 49.9±9.7, P = 0.002] with similar clinical characteristics for the pattern and severity of angina and other co-morbidities. 73.3% (n = 22) had abnormal functional disorders of the epicardial coronary arteries and/or coronary microcirculation. On multivariate analysis, OSA was the only statistically significant association with functional coronary microvascular disorders [OR 53.95, 1.41 -2065.01, P = 0.032]. This study provided an observation of a significant correlation between INOCA with abnormal coronary vasomotor function and OSA in an Australian cohort. This correlation supports a possible pathophysiological interplay between these two conditions that needs to be further evaluated. The benefit of treatment of OSA in this subset remains unknown.

Ischemia With Nonobstructive Coronary Artery Disease: Concept, Assessment, and Management

In daily clinical practice, physicians often encounter patients with angina or those with evidence of myocardial ischemia from noninvasive tests but not having obstructive coronary artery disease. This type of ischemic heart disease is referred to as ischemia with nonobstructive coronary arteries (INOCA). INOCA patients often suffer from recurrent chest pain without adequate management and are associated with poor clinical outcomes. There are several endotypes of INOCA, and each endotype should be treated based on its specific underlying mechanism. Therefore, identifying INOCA and discriminating its underlying mechanisms are important issues and of clinical interest. Invasive physiologic assessment is the first step in the diagnosis of INOCA and discriminating the underlying mechanism; additional provocation tests help physicians identify the vasospastic component in INOCA patients. Comprehensive information acquired from these invasive tests can provide a template for mechanism-specific management for patients with INOCA.

Myocardial infarction with non-obstructive coronary arteries: Etiology, diagnosis, treatment and prognosis

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is responsible for 10% of myocardial infarctions. Previously, patients were thought to have good prognosis, but evidence-based management and treatment strategies were scarce. Today, researchers and physicians recognize MINOCA as a condition with non-trivial mortality and morbidity. Therapeutic strategies are highly dependent on the underlying disease mechanism in each patient. However, to reach a diagnosis of MINOCA, a multimodal approach is required and, even with an optimal work-up, the cause remains unknown in 8-25% of patients. Research has been growing and position papers from the European Society of Cardiology (ESC) and the American Heart Association/American College of Cardiology have been published, and MINOCA has been included in the more recent ESC guidelines on myocardial infarction. Nonetheless, some clinicians still assume that the absence of coronary obstruction excludes the possibility of acute myocardial infarction. Therefore, in the present paper, we aim to compile and present the available data on the etiology, diagnosis, treatment, and prognosis of MINOCA.

ACR Appropriateness Criteria® Chronic Chest Pain-High Probability of Coronary Artery Disease: 2021 Update

Management of patients with chronic chest pain in the setting of high probability of coronary artery disease (CAD) relies heavily on imaging for determining or excluding presence and severity of myocardial ischemia, hibernation, scarring, and/or the presence, site, and severity of obstructive coronary lesions, as well as course of management and long-term prognosis. In patients with no known ischemic heart disease, imaging is valuable in determining and documenting the presence, extent, and severity of obstructive coronary narrowing and presence of myocardial ischemia. In patients with known ischemic heart disease, imaging findings are important in determining the management of patients with chronic myocardial ischemia and can serve as a decision-making tool for medical therapy, angioplasty, stenting, or surgery. This document summarizes the recent growing body of evidence on various imaging tests and makes recommendations for imaging based on the available data and expert opinion. This document is focused on epicardial CAD and does not discuss the microvascular disease as the cause for CAD. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Management of ischaemia with non-obstructive coronary arteries (INOCA)

Up to half of patients undergoing elective coronary angiography for the investigation of chest pain do not present with evidence of obstructive coronary artery disease. These patients are often discharged with a diagnosis of non-cardiac chest pain, yet many could have an ischaemic basis for their symptoms. This type of ischaemic chest pain in the absence of obstructive coronary artery disease is referred to as INOCA (ischaemia with non-obstructive coronary arteries). This comprehensive review of INOCA management looks at why these patients require treatment, who requires treatment based on diagnostic evaluation, what clinical treatment targets should be considered, how to treat patients using a personalised medicine approach, when to initiate treatment, and where future research is progressing.

Long-term outcome of patients with NSTEMI and nonobstructive coronary arteries by different angiographic subtypes

INTRODUCTION AND OBJECTIVES

Discordant data have been reported on the prognosis of myocardial infarction with nonobstructive coronary arteries (MINOCA). Moreover, few data are available on the impact of angiographic subtypes. The objectives of this study were to assess the prognostic impact on the long-term follow-up of the diagnosis of MINOCA and its angiographic subtypes.

METHODS

We included 591 consecutive patients with non-ST-segment elevation myocardial infarction (NSTEMI) who underwent coronary angiography. MINOCA was classified according to angiographic findings as smooth coronary arteries, mild irregularities (< 30% stenosis), and moderate atherosclerosis (30%-49% stenosis). The primary endpoint was a composite of mortality, nonfatal myocardial infarction, and revascularization (MACE) at a median of 5 years of follow-up.

RESULTS

A total of 121 patients (20.5%) showed no obstructive lesions. MINOCA was associated with a lower occurrence of MACE (P=.014; HR, 0.63; 95%CI, 0.44-0.91) and was confirmed as an independent factor in the multivariate analysis (P=.018; HR, 0.63; 95%CI, 0.43-0.92). On analysis of the separate components of the main endpoint, MINOCA was significantly associated with a lower rate of myocardial infarction and revascularization, but not with mortality. Analysis of angiographic subtypes among MINOCA patients showed that smooth coronary arteries were a statistically significant protective factor on both univariate and multivariate analysis, while mild irregularities and 30% to 49% plaques were associated with a higher risk of MACE.

CONCLUSIONS

MINOCA is associated with a lower rate of MACE, driven by fewer reinfarctions and revascularizations. Within the angiographic subtypes of MINOCA, smooth arteries were independently associated with a lower number of MACE.

Longitudinal myocardial function is more compromised in cardiac syndrome X compared to insignificant CAD: Role of stress echocardiography and calcium scoring

BACKGROUND AND AIM

The aim of this study was to assess the nature of myocardial dysfunction in the cardiac syndrome X (CSX) and insignificant coronary artery disease (ICAD) using dobutamine stress echocardiography (DSE) and coronary calcium scoring (CAC).

METHODS

We prospectively studied 35 consecutive patients who complained of exertional angina, had ≥1 mm ST shift on exercise stress test but normal or no obstructive CAD (<50%) on angiography. Patients were divided into CSX (n = 27) with normal arteries and ICAD (n = 8) with insignificant stenosis.

RESULTS

CSX patients had more females, lower calcium score and less prevalent cardiac risk factors compared to ICAD (p < 0.05 for all). At peak stress, MAPSE and TAPSE failed to increase in both groups. LV septal and lateral s' increased in the two groups but the increment increase was less in CSX than ICAD (p < 0.05) while other diastolic indices did not differ between groups (p > 0.05 for all). CAC correlated modestly with LV and RV systolic velocities: septal s' (r = -0.65, p < 0.001) lateral s' (r = -0.35, p = 0.04) and right s' (r = -0.53, p = 0.005) in CSX, while in ICAD patients only with RV s' (r = -0.58, p = 0.02). On multivariate model, only septal s' OR 1.816 (1.1090-3.820, p = 0.04) proved the most powerful independent predictor of CAC.

CONCLUSIONS

Compromised LV longitudinal systolic velocities were more pronounced and calcium score as a surrogate for atherosclerosis was lower in CSX than ICAD. These findings strengthen the evidence for different pathogenesis of CSX compared to ICAD, with microvascular disease in the former and calcification in the latter.

OCT Findings in MINOCA

Myocardial infarction with non-obstructive coronary artery disease (MINOCA) is a working diagnosis for patients presenting with acute myocardial infarction without obstructive coronary artery disease on coronary angiography. It is a heterogenous entity with a number of possible etiologies that can be determined through the use of appropriate diagnostic algorithms. Common causes of a MINOCA may include plaque disruption, spontaneous coronary artery dissection, coronary artery spasm, and coronary thromboembolism. Optical coherence tomography (OCT) is an intravascular imaging modality which allows the differentiation of coronary tissue morphological characteristics including the identification of thin cap fibroatheroma and the differentiation between plaque rupture or erosion, due to its high resolution. In this narrative review we will discuss the role of OCT in patients presenting with MINOCA. In this group of patients OCT has been shown to reveal abnormal findings in almost half of the cases. Moreover, combining OCT with cardiac magnetic resonance (CMR) was shown to allow the identification of most of the underlying mechanisms of MINOCA. Hence, it is recommended that both OCT and CMR can be used in patients with a working diagnosis of MINOCA. Well-designed prospective studies are needed in order to gain a better understanding of this condition and to provide optimal management while reducing morbidity and mortality in that subset patients.

[Efficacy and Safety of Combined Treament with Ivabradine and Metoprolol in Patients with Stable Angina Pectoris - a Systematic Review]

This article presents results of a systematic review, which was designed for evaluating the effect of combination treatment with ivabradine and metoprolol on heart rate, frequency of angina attacks, frequency of using short-acting nitrates, and angina severity. The analysis included data from three large observational studies on efficacy of the ivabradine and metoprolol tartrate combination in patients with chronic angina. Results of the analysis supported the efficacy of the metoprolol and ivabradine combination in clinical practice, which provided effective decreases in the heart rate, frequency of angina attacks, requirement for short-acting nitrates, and alleviation of angina severity. The studies demonstrated good tolerability of this treatment.

Predictors of Mortality in Myocardial Infarction and Nonobstructed Coronary Arteries: A Systematic Review and Meta-Regression

BACKGROUND

The long-term mortality of patients with myocardial infarction and nonobstructed coronary arteries (MINOCA) remains poorly defined. This study aimed to determine the long-term mortality of patients with MINOCA and to identify potential prognostic determinants of long-term outcome.

METHODS

We searched PubMed, EMBASE, and Cochrane databases and reviewed cited references up to December 31, 2018 to identify studies with >6 months' follow-up data.

RESULTS

We selected 44 studies including 36,932 patients (20,052 women and 16,880 men). During a median follow-up of 25 months (interquartile range: 23-39 months), 1409 patients had died (3.8%). Overall, annual mortality rate was 2.0% (95% confidence interval [CI]: 1.5% to 2.4%), with significant heterogeneity (I² = 80%, P < .001). Meta-analysis of the 26 studies comparing patients with MINOCA with those with myocardial infarction and obstructive coronary artery disease showed that annual rates of long-term total mortality were 2.2% (95% CI: 1.7% to 2.7%) and 5.0% (95% CI: 4.1% to 5,9%), respectively, with a significant difference between the two groups (relative risk: 0.60, 95% CI: 0.46 to 0.78, P < .001). Meta-regression analysis demonstrated that normal ejection fraction (P ≤ .0001) and normal coronary arteries at angiography (P = .004) were inversely related to long-term mortality, whereas use of beta-blockers during follow-up (P = .010) and ST depression on the admission electrocardiogram (P = .016) were directly related with worse outcome.

CONCLUSIONS

The long-term mortality after MINOCA is lower than that in patients with myocardial infarction and obstructive coronary artery disease, but it is not trivial. Reduced ejection fraction, nonobstructive coronary artery disease, use of beta-blockers during follow up and ST depression on the admission electrocardiogram are significant predictors of long-term prognosis.

Reinfarction in Patients with Myocardial Infarction with Nonobstructive Coronary Arteries (MINOCA): Coronary Findings and Prognosis

BACKGROUND

Myocardial infarction (MI) with nonobstructive coronary arteries (MINOCA) is common. There are limited data on the mechanisms and prognosis for reinfarction in MINOCA patients.

METHODS

In this observational study of MINOCA patients hospitalized in Sweden and registered in the SWEDEHEART registry between July 2003 and June 2013 and followed until December 2013, we identified 9092 unique patients with MINOCA of 199,163 MI admissions in total. The 570 (6.3%) MINOCA patients who were hospitalized due to a recurrent MI constituted the study group.

RESULTS

The mean age was 69.1 years and 59.1% were women. The median time to readmission was 17 months. A total of 340 patients underwent a new coronary angiography and 180 (53%) had no obstructive coronary artery disease (CAD) and 160 (47%) had obstructive CAD; 123 had 1-vessel, 26 had 2-vessel, 9 had 3-vessel disease, and 2 had left main together with 1-vessel disease. Male sex, diabetes, peripheral vascular disease, higher levels of creatinine, and ST elevation at presentation were more common in patients with MI with obstructive CAD than in patients with a recurrent MINOCA. Mortality during a median follow-up of 38 months was similar whether the reinfarction event was MINOCA or MI with obstructive CAD 13.9% vs 11.9% (P = .54).

CONCLUSIONS

About half of patients with reinfarction after MINOCA who underwent coronary angiography had progression of coronary stenosis. Angiography should be strongly considered in patients with MI after MINOCA. Mortality associated with recurrent events was substantial, though there was no difference in mortality between those with or without significant CAD.

Predictors of adverse outcome in patients with myocardial infarction with non-obstructive coronary artery (MINOCA) disease

BACKGROUND

Myocardial infarction (MI) with non-obstructive coronary arteries (MINOCAs) is an increasingly recognized entity. No previous study has evaluated predictors for new major adverse cardiacvascular events (MACEs) and death in patients with MINOCA.

METHODS

We conducted an observational study of MINOCA patients recorded between July 2003 and June 2013 and followed until December 2013 for outcome events. Out of 199,163 MI admissions, 9092 consecutive unique patients with MINOCA were identified. The mean age was 65.5 years and 62% were women. MACE was defined as all-cause mortality, rehospitalization for acute MI, ischemic stroke and heart failure. Hazard ratio and 95% confidence interval (HR; 95% CI) was calculated using Cox-regression.

RESULTS

A total of 2147 patients (24%) experienced a new MACE and 1254 patients (14%) died during the mean follow-up of 4.5 years. Independent predictors for MACE after adjustment, were older age (1.05; 1.04-1.06), diabetes (1.44; 1.21-1.70), hypertension (1.25; 1.09-1.43), current smoking (1.38; 1.15-1.66), previous myocardial infarction (1.38; 1.04-2.82), previous stroke (1.69; 1.35-2.11), peripheral vascular disease (1.55; 1.97-2.23), chronic obstructive pulmonary disease (1.63; 1.32-2.00), reduced left ventricular ejection fraction (2.00; 1.54-2.60), lower level of total cholesterol (0.88; 0.83-0.94) and higher level of creatinine (1.01; 1.00-1.03). Independent predictors for all cause death were age, current smoking, diabetes, cancer, chronic obstructive pulmonary disease, previous stroke, reduced left ventricular fraction, lower level of total cholesterol and higher levels of creatinine and CRP.

CONCLUSIONS

The clinical factors predicting new MACE and death of MINOCA patients seem to be strikingly similar to factors previously shown to predict new cardiovascular events in patients with MI and obstructive coronary artery disease.

Ranolazine for stable angina pectoris

BACKGROUND

Stable angina pectoris is a chronic medical condition with significant impact on mortality and quality of life; it can be macrovascular or microvascular in origin. Ranolazine is a second-line anti-anginal drug approved for use in people with stable angina. However, the effects of ranolazine for people with angina are considered to be modest, with uncertain clinical relevance.

OBJECTIVES

To assess the effects of ranolazine on cardiovascular and non-cardiovascular mortality, all-cause mortality, quality of life, acute myocardial infarction incidence, angina episodes frequency and adverse events incidence in stable angina patients, used either as monotherapy or as add-on therapy, and compared to placebo or any other anti-anginal agent.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase and the Conference Proceedings Citation Index - Science in February 2016, as well as regional databases and trials registers. We also screened reference lists.

SELECTION CRITERIA

Randomised controlled trials (RCTs) which directly compared the effects of ranolazine versus placebo or other anti-anginals in people with stable angina pectoris were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two authors independently selected studies, extracted data and assessed risk of bias. Estimates of treatment effects were calculated using risk ratios (RR), mean differences (MD) and standardised mean differences (SMD) with 95% confidence intervals (CI) using a fixed-effect model. Where we found statistically significant heterogeneity (Chi² P < 0.10), we used a random-effects model for pooling estimates. Meta-analysis was not performed where we found considerable heterogeneity (I² ≥ 75%). We used GRADE criteria to assess evidence quality and the GRADE profiler (GRADEpro GDT) to import data from Review Manager 5.3 to create 'Summary of findings' tables.

MAIN RESULTS

We included 17 RCTs (9975 participants, mean age 63.3 years). We found very limited (or no) data to inform most planned comparisons. Summary data were used to inform comparison of ranolazine versus placebo. Overall, risk of bias was assessed as unclear.For add-on ranolazine compared to placebo, no data were available to estimate cardiovascular and non-cardiovascular mortality. We found uncertainty about the effect of ranolazine on: all-cause mortality (1000 mg twice daily, RR 0.83, 95% CI 0.26 to 2.71; 3 studies, 2053 participants; low quality evidence); quality of life (any dose, SMD 0.25, 95% CI -0.01 to 0.52; 4 studies, 1563 participants; I² = 73%; moderate quality evidence); and incidence of non-fatal acute myocardial infarction (AMI) (1000mg twice daily, RR 0.40, 95% CI 0.08 to 2.07; 2 studies, 1509 participants; low quality evidence). Add-on ranolazine 1000 mg twice daily reduced the fervour of angina episodes (MD -0.66, 95% CI -0.97 to -0.35; 3 studies, 2004 participants; I² = 39%; moderate quality evidence) but increased the risk of non-serious adverse events (RR 1.22, 95% CI 1.06 to 1.40; 3 studies, 2053 participants; moderate quality evidence).For ranolazine as monotherapy compared to placebo, we found uncertain effect on cardiovascular mortality (1000 mg twice daily, RR 1.03, 95% CI 0.56 to 1.88; 1 study, 2604 participants; low quality evidence). No data were available to estimate non-cardiovascular mortality. We also found an uncertain effect on all-cause mortality for ranolazine (1000 mg twice daily, RR 1.00, 95% CI 0.81 to 1.25; 3 studies, 6249 participants; low quality evidence), quality of life (1000 mg twice daily, MD 0.28, 95% CI -1.57 to 2.13; 3 studies, 2254 participants; moderate quality evidence), non-fatal AMI incidence (any dose, RR 0.88, 95% CI 0.69 to 1.12; 3 studies, 2983 participants; I² = 50%; low quality evidence), and frequency of angina episodes (any dose, MD 0.08, 95% CI -0.85 to 1.01; 2 studies, 402 participants; low quality evidence). We found an increased risk for non-serious adverse events associated with ranolazine (any dose, RR 1.50, 95% CI 1.12 to 2.00; 3 studies, 947 participants; very low quality evidence).

AUTHORS' CONCLUSIONS

We found very low quality evidence showing that people with stable angina who received ranolazine as monotherapy had increased risk of presenting non-serious adverse events compared to those given placebo. We found low quality evidence indicating that people with stable angina who received ranolazine showed uncertain effect on the risk of cardiovascular death (for ranolazine given as monotherapy), all-cause death and non-fatal AMI, and the frequency of angina episodes (for ranolazine given as monotherapy) compared to those given placebo. Moderate quality evidence indicated that people with stable angina who received ranolazine showed uncertain effect on quality of life compared with people who received placebo. Moderate quality evidence also indicated that people with stable angina who received ranolazine as add-on therapy had fewer angina episodes but increased risk of presenting non-serious adverse events compared to those given placebo.

Emerging drugs for the treatment of angina pectoris

INTRODUCTION

Angina pectoris, or symptomatic myocardial ischaemia, reflects an impairment of coronary blood flow, and usually a deficiency of available myocardial energetics. Treatment options vary with the precise cause, which may vary with regards to the roles of increased myocardial oxygen demand versus reduced supply. Traditionally, organic nitrates, β-adrenoceptor antagonists, and non-dihydropyridine calcium antagonists were the only commonly used prophylactic anti-anginal agents. However, many patients failed to respond adequately to such therapy, and/or were unsuitable for their use. Areas covered: A number of 'new' agents have been shown to represent ancillary forms of prophylactic anti-anginal therapy and are particularly useful in patients who are relatively unsuitable for either percutaneous or surgical revascularisation. These include modulators of myocardial metabolic efficiency, such as perhexiline, trimetazidine and ranolazine, as well as high dose allopurinol, nicorandil and ivabradine. The advantages and disadvantages of these various agents are summarized. Expert opinion: 'Optimal' medical treatment of angina pectoris now includes use of agents primarily intended to reduce risk of infarction (e.g. statins, aspirin, ACE inhibitors). In patients whose angina persists despite the use of 'standard' anti-anginal therapy, and who are not ideal for invasive revascularization options, a number of emerging drugs offer prospects of symptomatic relief.

Pharmacotherapy of Vasospastic Angina

Vasospastic angina is a diagnosis of exclusion that manifests with signs and symptoms, which overlap with obstructive coronary artery disease, most often ST-segment elevation myocardial infarction. The pharmacotherapy that is available to treat vasospastic angina can help ameliorate angina symptoms. However, the etiology of vasospastic angina is ill-defined, making targeted pharmacotherapy difficult. Most patients receive pharmacotherapy that includes calcium channel blockers and/or long-acting nitrates. This article reviews the efficacy and safety of the pharmacotherapy used to treat vasospastic angina. High-dose calcium channel blockers possess the most evidence, with respect to decreasing angina incidence, frequency, and duration. However, not all patients respond to calcium channel blockers. Nitrates and/or alpha1-adrenergic receptor antagonists can be used in patients who respond poorly to calcium channel blockers. Albeit, evidence for use of nitrates and alpha1-adrenergic receptor antagonists in vasospastic angina is not as robust as calcium channel blockers and can exacerbate adverse effects when added to calcium channel blocker therapy. Despite having a clear benefit in patients with obstructive coronary artery disease, the benefit of beta-adrenergic receptor antagonists, statins, and aspirin remains unclear. More data are needed to elucidate whether or not these agents are beneficial or harmful to patients being treated for vasospastic angina. Overall, the use of pharmacotherapy for the treatment of vasospastic angina should be guided by patient-specific factors, such as tolerability, adverse effects, drug–drug, and drug–disease interactions.

Cardiac Syndrome X: Update

Cardiac Syndrome X (CSX), characterized by angina-like chest discomfort, ST segment depression during exercise, and normal epicardial coronary arteries at angiography, is highly prevalent in women. CSX is not benign, and linked to adverse cardiovascular outcomes and a poor quality of life. Coronary microvascular and endothelial dysfunction and abnormal cardiac nociception have been implicated in the pathogenesis of CSX. Treatment includes life-style modification, anti-anginal, anti-atherosclerotic, and anti-ischemic medications. Non-pharmacological options include cognitive behavioral therapy, enhanced external counterpulsation, neurostimulation, and stellate ganglionectomy. Studies have shown the efficacy of individual treatments but guidelines outlining the best course of therapy are lacking.

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.

Current Diagnostic and Therapeutic Strategies in Microvascular Angina

Microvascular angina is common among patients with signs and symptoms of acute coronary syndrome and is associated with an increased risk of cardiovascular and cerebrovascular events. Unfortunately, microvascular is often under-recognized in clinical settings. The diagnosis of microvascular angina relies on assessment of the functional status of the coronary microvasculature. Invasive strategies include acetylcholine provocation, intracoronary Doppler ultrasound, and intracoronary thermodilution; noninvasive strategies include cardiac positron emission tomography (PET), cardiac magnetic resonance, and Doppler echocardiography. Once the diagnosis of microvascular angina is established, treatment is focused on improving symptoms and reducing future risk of cardiovascular and cerebrovascular events. Pharmacologic options and lifestyle modifications for patients with microvascular angina are similar to those for patients with coronary artery disease.

Gender-specific research for emergency diagnosis and management of ischemic heart disease: proceedings from the 2014 Academic Emergency Medicine Consensus Conference Cardiovascular Research Workgroup

Coronary artery disease (CAD) is the most common cause of death for both men and women. However, over the years, emergency physicians, cardiologists, and other health care practitioners have observed varying outcomes in men and women with symptomatic CAD. Women in general are 10 to 15 years older than men when they develop CAD, but suffer worse postinfarction outcomes compared to age-matched men. This article was developed by the cardiovascular workgroup at the 2014 Academic Emergency Medicine (AEM) consensus conference to identify sex- and gender-specific gaps in the key themes and research questions related to emergency cardiac ischemia care. The workgroup had diverse stakeholder representation from emergency medicine, cardiology, critical care, nursing, emergency medical services, patients, and major policy-makers in government, academia, and patient care. We implemented the nominal group technique to identify and prioritize themes and research questions using electronic mail, monthly conference calls, in-person meetings, and Web-based surveys between June 2013 and May 2014. Through three rounds of nomination and refinement, followed by an in-person meeting on May 13, 2014, we achieved consensus on five priority themes and 30 research questions. The overarching themes were as follows: 1) the full spectrum of sex-specific risk as well as presentation of cardiac ischemia may not be captured by our standard definition of CAD and needs to incorporate other forms of ischemic heart disease (IHD); 2) diagnosis is further challenged by sex/gender differences in presentation and variable sensitivity of cardiac biomarkers, imaging, and risk scores; 3) sex-specific pathophysiology of cardiac ischemia extends beyond conventional obstructive CAD to include other causes such as microvascular dysfunction, takotsubo, and coronary artery dissection, better recognized as IHD; 4) treatment and prognosis are influenced by sex-specific variations in biology, as well as patient-provider communication; and 5) the changing definitions of pathophysiology call for looking beyond conventionally defined cardiovascular outcomes to patient-centered outcomes. These emergency care priorities should guide future clinical and basic science research and extramural funding in an area that greatly influences patient outcomes.

Cardiac Syndrome X: update 2014

Cardiac Syndrome X (CSX), characterized by angina-like chest discomfort, ST segment depression during exercise, and normal epicardial coronary arteries at angiography, is highly prevalent in women. CSX is not benign, and linked to adverse cardiovascular outcomes and a poor quality of life. Coronary microvascular and endothelial dysfunction and abnormal cardiac nociception have been implicated in the pathogenesis of CSX. Treatment includes life-style modification, anti-anginal, anti-atherosclerotic, and anti-ischemic medications. Non-pharmacological options include cognitive behavioral therapy, enhanced external counterpulsation, neurostimulation, and stellate ganglionectomy. Studies have shown the efficacy of individual treatments but guidelines outlining the best course of therapy are lacking.