Coronary artery spasm: review and update

Coronary artery spasm following dobutamine stress echocardiogram

A 53-year-old woman with atypical chest pain underwent a dobutamine stress echocardiogram (DSE) and developed a coronary spasm (CS) with severe pain and dramatic ST-segment elevation 9 min after dobutamine infusion was discontinued. The spasm resolved after sublingual nitroglycerin administration. The same-day coronary angiogram showed non-significant stenosis in the three coronary territories. Retrospectively, we found that the patient had vasospastic angina (VSA), a condition that has been strongly associated with the development of dobutamine-induced CS. Mechanisms of dobutamine-induced CS are not fully understood and include endothelial dysfunction leading to deficient nitric oxide-mediated coronary vasodilation in response to increased myocardial oxygen demand as well as imbalance between β1 and β2 adrenergic effects of dobutamine. Dobutamine-induced CS has also been much more frequently reported in patients from Asian descent with VSA. VSA should be systemically recognised in patients considered for DSE and, if present, other modalities of stress imaging should be discussed.

Successful cryoablation of left ventricular summit premature ventricular contractions via the coronary sinus

The left ventricular summit (LVS) is a challenging location for catheter-based percutaneous ablation due to its anatomical location. There have been case reports of cryoablations performed in this region, but the technique may be underutilized when radiofrequency ablation fails. A 45-year-old male was found to have 25 000 premature ventricular contractions (PVCs) a day despite previous ablation and a reduced ejection fraction of 40% despite medical therapy. Coronary sinus epicardial mapping revealed the coronary sinus distal region generated activations earlier than the QRS onset by 28 ms. Two separate, 4-minute cryoablations were delivered that suppressed the PVCs within 5 seconds. Alternate energy modalities such as cryo may offer a safer and more viable approach for ablation of LVS in select patients.

Coronary Artery Spasm: New Insights

Coronary artery spasm (CAS) defined by a severe reversible diffuse or focal vasoconstriction is the most common diagnosis among INOCA (ischemia with no obstructive coronary artery disease) patients irrespective to racial, genetic, and geographic variations. However, the prevalence of CAS tends to decrease in correlation with the increasing use of medicines such as calcium channel blockers, angiotensin converting enzyme inhibitor, and statins, the controlling management of atherosclerotic risk factors, and the decreased habitude to perform a functional reactivity test in highly active cardiac catheterization centers. A wide spectrum of clinical manifestations from silent disease to sudden cardiac death was attributed to this complex entity with unclear pathophysiology. Multiple mechanisms such as the autonomic nervous system, endothelial dysfunction, chronic inflammation, oxidative stress, and smooth muscle hypercontractility are involved. Regardless of the limited benefits proffered by the newly emerged cardiac imaging modalities, the provocative test remains the cornerstone diagnostic tool for CAS. It allows to reproduce CAS and to evaluate reactivity to nitrates. Different invasive and noninvasive therapeutic approaches are approved for the management of CAS. Long-acting nondihydropyridine calcium channel blockers are recommended for first line therapy. Invasive strategies such as PCI (percutaneous coronary intervention) and CABG (coronary artery bypass graft) have shown benefits in CAS with significant atherosclerotic lesions. Combination therapies are proposed for refractory cases.

ST segment elevation in an adult chest pain patient: A case of coronary artery vasospasm

Chest pain is one of the most common symptoms of patients presenting to the emergency department (ED) in the United States, accounting for up to eight million cases annually. We present a 55-year-old male who was brought in to the ED with sudden onset chest pain and was found to have ST-segment elevations in the infero-lateral leads on electrocardiogram (ECG). These changes resolved with nitroglycerin. Coronary artery vasospasm was diagnosed as coronary angiogram was normal. Calcium channel blocker was prescribed with good symptom relief. The most important teaching point is, coronary vasospasm as a cause of ST-segment elevation is missed frequently and should be considered among the differentials in patients presenting with chest pain. Nitrates and/or calcium channel blockers along with avoidance of triggers can help in symptom management.

Diagnostic Utility and Pathogenic Role of Circulating MicroRNAs in Vasospastic Angina

We investigated the diagnostic value and pathophysiological role of circulating microRNA (miR) in vasospastic angina (VA). We enrolled patients who underwent coronary angiography for chest pain to explore the miR’s diagnostic utility. In addition, we investigated the role of miRs in regulating endothelial nitric oxide synthase (eNOS) expression in human coronary artery endothelial cells (hCAECs). Among the 121 patients, 46 were diagnosed with VA (VA group), 26 with insignificant coronary lesions (ICL group), and 49 with atherothrombotic angina (AA group). The VA group showed a significantly higher expression of miR-17-5p, miR-92a-3p, and miR-126-3p than the ICL group. In contrast, miR-221-3p and miR-222-3p were upregulated in the AA group compared to the VA group, and all levels of miR-17-5p, miR-92a-3p, miR-126-3p, miR-145-5p, miR-221-3p, and miR-222-3p differed between the AA group and the ICL group. In the hCAECs, transfection with mimics (pre-miR) of miR-17-5p, miR-92a-3p, and miR-126-3p was associated with eNOS suppression. Additionally, transfection with inhibitors (anti-miR) of miR-92a-3p significantly rescued the eNOS suppression induced by lipopolysaccharide. In conclusion, the circulating miRs not only proved to have diagnostic utility, but also contributed to pathogenesis by eNOS regulation.

Vasospastic Arrest

Vasospastic angina is an uncommon cause of cardiac arrest. We describe a patient who presented with sudden cardiac arrest due to severe coronary vasospasm. Telemetry during the event revealed ventricular arrhythmias and asystole followed by spontaneous self-conversion back to normal sinus rhythm. The patient underwent implantable cardioverter-defibrillator therapy. (Level of Difficulty: Beginner.)

Vasospastic angina: pathophysiology and clinical significance

The review discusses an analysis of the literature on various aspects of the pathogenesis, diagnosis and treatment of vasospastic angina (VA). Data on the prevalence of coronary artery spasm (CAS) in various populations, as well as risk factors and triggers, are presented. We considered pathophysiological mechanisms of CAS, including hyperreactivity of coronary smooth muscle cells, endothelial dysfunction, nonspecific inflammation, oxidative stress, magnesium deficiency, autonomic imbalance, etc. The relationship of CAS with coronary atherosclerosis and thrombosis is emphasized. Modern recommendations for the diagnosis and treatment of VA are presented. Invasive verification of CAS is performed by pharmacological provocation tests with certain contraindications. Calcium antagonists and their combination with long-acting nitrates play a key role in the treatment of VA. Medications with a prospect for use in VA are Rho-kinase inhibitors, ATP-sensitive potassium channel activators, alpha-1 blockers. The management of patients with refractory VA and the prospects for endovascular treatment are discussed. It was noted that patients with multi-vessel VA are more likely to develop life-threatening arrhythmias and sudden death.

Chest pain in Brugada syndrome: Prevalence, correlations, and prognosis role

BACKGROUND

Brugada syndrome (BrS) is sometimes diagnosed because of chest pain. Prevalence and characteristics of such BrS patients are unknown.

METHODS

A total of 200 BrS probands were retrospectively included. BrS diagnosis made because of chest pain (n = 34, 17%) was compared to the other ones.

RESULTS

BrS probands with diagnosis because of chest pain had significantly more often smoker habits, increased body mass index, and familial history of coronary artery disease but less frequently previous resuscitated sudden death/syncope or atrial fibrillation. Presence of coronary spasm and familial coronary artery disease were independently associated with BrS diagnosed because of chest pain. They presented more often with spontaneous type 1 ST elevation (59% vs 26%, P = .0004) and higher ST elevation during the episode of chest pain compared to other patients or compared to baseline electrocardiogram after chest pain resumption. ST elevation during chest pain was lower compared to ajmaline test. A total of 20% of them had significant coronary artery disease and four (11%) had coronary spasm, and they experienced more often recurrent chest pain episodes (24% vs 5%, P = .0002). Presence of chest pain at BrS diagnosis was not correlated to future arrhythmic events in univariate analysis. Only previous sudden cardiac death (SD)/syncope and familial SD were still significantly associated with outcome in multivariate analysis.

CONCLUSION

Chest pain is a common cause for BrS diagnosis, although major part is not apparently explained by ischemic heart disease. Mechanisms leading to chest main remain unknown in the other ones. ST elevation is higher in this situation but does not seem to carry poor prognosis.

Diagnosis of myocardial infarction at autopsy: AECVP reappraisal in the light of the current clinical classification

Ischemic heart disease is one of the leading causes of morbidity and death worldwide. Consequently, myocardial infarctions are often encountered in clinical and forensic autopsies, and diagnosis can be challenging, especially in the absence of an acute coronary occlusion. Precise histopathological identification and timing of myocardial infarction in humans often remains uncertain while it can be of crucial importance, especially in a forensic setting when third person involvement or medical responsibilities are in question. A proper post-mortem diagnosis requires not only up-to-date knowledge of the ischemic coronary and myocardial pathology, but also a correct interpretation of such findings in relation to the clinical scenario of the deceased. For these reasons, it is important for pathologists to be familiar with the different clinically defined types of myocardial infarction and to discriminate myocardial infarction from other forms of myocardial injury. This article reviews present knowledge and post-mortem diagnostic methods, including post-mortem imaging, to reveal the different types of myocardial injury and the clinical-pathological correlations with currently defined types of myocardial infarction.

Short-term exposure to desert dust and the risk of acute myocardial infarction in Japan: a time-stratified case-crossover study

Particulate matter from natural sources such as desert dust causes harmful effects for health. Asian dust (AD) increases the risk of acute myocardial infarction (AMI). However, little is known about the risk of myocardial infarction with nonobstructive coronary arteries (MINOCA), compared to myocardial infarction with coronary artery disease (MI-CAD). Using a time-stratified case-crossover design and conditional logistic regression models, the association between short-term exposure to AD whereby decreased visibility (< 10 km) observed at each monitoring station nearest to the hospitals was used for exposure measurements and admission for AMI in the spring was investigated using a nationwide administrative database between April 2012 and March 2016. According to presence of revascularization and coronary atherosclerosis, AMI patients (n = 30,435) were divided into 2 subtypes: MI-CAD (n = 27,202) or MINOCA (n = 3233). The single lag day-2 was used in AD exposure based on the lag effect analysis. The average level of meteorological variables and co-pollutants on the 3 days prior to the case/control days were used as covariates. The occurrence of AD events 2 days before the admission was associated with admission for MINOCA after adjustment for meteorological variables [odds ratio 1.65; 95% confidence interval (CI) 1.18-2.29], while the association was not observed in MI-CAD. The absolute risk difference of MINOCA admission was 1.79 (95% CI 1.21-2.38) per 100,000 person-year. These associations between AD exposure and the admission for MINOCA remained unchanged in two-pollutant models. This study provides evidence that short-term exposure to AD is associated with a higher risk of MINOCA, but not MI-CAD.

Myocardial Ischemic Syndromes, Heart Failure Syndromes, Electrocardiographic Abnormalities, Arrhythmic Syndromes and Angiographic Diagnosis of Coronary Artery Spasm: Literature Review

In coronary artery spasm (CAS), an excess coronary vasoconstriction causing total or subtotal vessel occlusion could lead to syncope, heart failure syndromes, arrhythmic syndromes, and myocardial ischemic syndromes including asymptomatic myocardial ischemia, stable and unstable angina, acute myocardial infarction, and sudden cardiac death. Although the clinical significance of CAS has been underrated because of the frequent absence of symptoms, affected patients appear to be at higher risk of syncope, serious arrhythmias, and sudden death than those with classic Heberden's angina pectoris. Therefore, a prompt diagnosis has important therapeutic implications, and is needed to avoid CAS-related complications. While a definitive diagnosis is based mainly on coronary angiography and provocative testing, clinical features may help guide decision-making. We perform a literature review to assess the past and current state of knowledge regarding the clinical features, electrocardiographic abnormalities and angiographic diagnosis of CAS, while a discussion of mechanisms is beyond the scope of this review.

Acute Myocardial Infarction in Young Individuals

Globally, cardiovascular disease remains a major cause of adverse outcomes in young individuals, unlike its decline in other age groups. This group is not well studied and has a unique risk profile with less traditional cardiovascular risk factors compared with older populations. Plaque rupture still remains the most common etiology of myocardial infarction, but unique syndromes such as plaque erosion, coronary microvascular dysfunction, spontaneous coronary artery dissection, and coronary spasm related to drug use are more prevalent in this age group. Such diversity of diagnosis and presentation, along with therapeutic implications, underscore the need to study the profile of myocardial infarction in young persons. We searched PubMed for articles published from 1980 to 218 using the terms acute myocardial infarction, young, plaque rupture, plaque erosion, spontaneous coronary artery dissection (SCAD), coronary vasospasm, variant or Prinzmetal angina, drug-induced myocardial infarction, myocarditis, coronary embolism, microvascular dysfunction, MINOCA, and myocardial infarction in pregnancy and reviewed all the published studies. With the data from this search, we aim to inform readers of the prevalence, risk factors, presentation, and management of acute myocardial infarction in young patients and elaborate on special subgroups with diagnostic and therapeutic challenges. We also outline a parsimonious method designed to simplify management of these complex patients.

Refractory Ventricular Tachycardia From Coronary Vasospasm During Pregnancy

Background: Coronary vasospasm leading to variant angina is uncommon, and the condition is rare in pregnant patients. Many physiologic changes occur during pregnancy, but how these changes affect the spasticity of coronary arteries in patients predisposed to vasospasm is unknown. Vasospasm causing unstable arrhythmia from multiple foci can be difficult to treat.

Case Report: A 22-year-old gravida 1 para 0 female at 17 weeks’ gestation with twins presented with chest pain refractory to sublingual nitroglycerin, ST segment elevation on electrocardiogram, and subsequent ventricular tachycardia requiring a shock by her implantable cardioverter defibrillator (ICD). The patient had a history of coronary vasospasm with ventricular arrhythmia that required placement of the ICD 5 years prior. Because of refractory symptoms, she required prolonged admission in the intensive care unit with high-dose intravenous nitroglycerin, calcium channel blockers, benzodiazepines, beta blockers, chemical sympathectomy, and intubation and sedation. Despite these measures, the patient continued to have vasospasm and ventricular tachycardia, so cesarean delivery and tubal ligation were performed. After delivery, she was rapidly weaned from all invasive treatment modalities and was discharged on oral nitrates and calcium channel blockers.

Conclusion: To our knowledge, this case is the first report of severe drug-refractory vasospastic angina triggered by pregnancy. The hormonal and nervous system changes that occur during pregnancy appear to be a trigger for vasospasm, further highlighted by the quick resolution of the patient's symptoms postdelivery. A multidisciplinary approach for treatment of both mother and baby was necessary. Our case provides a cautionary tale that patients with refractory vasospastic angina may want to pursue definitive contraception.

[Prinzmetal angina. Questions of pathogenesis, clinic, diagnosis and treatment]

Current problems of Prinzmetal angina (vasospastic angina, variant angina) considers in this review. Attention is drawn to early diagnosis, which should be comprehensive, taking into account possible atypical courses and the development of complications. The important role of electrocardiographic monitoring (including using implantable recorders) is highlighted. It is emphasized that patients with cardiac arrhythmias, syncope are at high risk of developing sudden cardiac death. In this category of patients, it is recommended to timely determine the indications for implantation of a cardioverter - defibrillator. Authors consider the prospects of using new methods of treatment of angina pectoris.

The functional assessment of patients with non-obstructive coronary artery disease: expert review from an international microcirculation working group

Symptomatic non-obstructive coronary artery disease (NOCAD) is an increasingly recognised entity that is associated with poor cardiovascular outcomes. Nearly half of those undergoing coronary angiography for appropriate indications, such as typical angina, or a positive stress test have no obstructive lesion. There are no guideline recommendations as to how to care properly for these patients. Physiologic assessment of the coronary arteries beyond two-dimensional angiography is not standardised, yet it can provide valuable information in patients presenting with typical angina in the setting of NOCAD. In this consensus document, we detail steps for the interventional cardiologist to evaluate the patient with symptomatic NOCAD in the cardiac catheterisation laboratory, first with the assessment of coronary flow reserve (CFR), and then with delineation of deficiencies in non-endothelium-dependent CFR (CFRne) versus endothelium-dependent CFR (CFRe) using provocative agents such as adenosine and acetylcholine, respectively, followed by the evaluation of smooth muscle function with nitroglycerine (NTG). Once the mechanism behind the anginal symptoms is established, one can identify the appropriate treatment strategies to address the physiologic deficiency that is present. Despite an established safety profile, a comprehensive assessment may be considered for selected patients which requires an understanding of the appropriate invasive evaluation by the practising interventional cardiologist when evaluating not only patients with obstructive CAD but also those with NOCAD.

Late perioperative native coronary artery spasm following bypass grafting in a patient with anomalous aortic origin of the coronary artery

Native right coronary artery (RCA) spasm is a less frequent early complication of perioperative coronary artery bypass grafting. Late presentation at 6 days postoperation is scarce and its relationship with an anomalous coronary artery is unknown. The optimal management and prevention remains controversial. In the case presented, the patient's anomalous left coronary artery originating from the right coronary cusp underwent ligation at its proximal segment at the time of bypass grafting. This ligation was preformed to prevent competitive flow. Six days postoperation, a refractory spasm of dominant native RCA occurred. The spasm resulted in right ventricular failure. Administration of intracoronary verapamil had a longer sustained vasodilatory effect and resolution of coronary spasm when compared with intracoronary nitroglycerine injection. An intra-aortic balloon pump, inotropic agents and low-dose nitroglycerine were used to maintain adequate haemodynamic support. Right ventricular systolic function recovery was noted within 2 days postintervention.

Noninvasive Recanalization of a Coronary Chronic Total Occlusion

BACKGROUND

Spontaneous recanalization of a chronically occluded artery is rare and reported anecdotally.

CASE SUMMARY

We report a case of a patient with a chronically occluded right coronary artery, found on a coronary angiography performed due to acute ST elevation myocardial infarction with an occluded circumflex artery as a culprit lesion. Three months later, a follow-up angiography was performed and a recanalization of the occluded right coronary artery was detected.

DISCUSSION

There is a possibility that intrinsic fibrinolytic mechanisms with the additional effect of standard antithrombotic drugs administrated after the acute coronary event led to the recanalization.

Spontaneous coronary vasospasm due to polytrauma

Coronary vasospasm is characterized by focal or diffuse spasm of an epicardial coronary artery. Definitive diagnosis is usually made with coronary angiography, when resolution of stenosis is observed after administration of intracoronary vasodilators. Coronary vasospasm is rarely a consequence of a blunt force injury to the chest. Among trauma induced cardiac complications, coronary vasospasm has been the least common with only one other reported case of coronary vasospasm induced by trauma. We report a rare case of severe spontaneous coronary vasospasm in a patient with polytrauma successfully treated with intracoronary, intravenous and oral vasodilator therapy. The mechanism is thought to be due to compensatory catecholamine response to trauma, and coronary vasospasm should be strongly suspected in trauma patients with unexplained hypotension, new conduction abnormalities or evidence of ischemia on the ECG.

A Curious Case of Coronary Vasospasm with Cardiogenic Shock: Type 1 Kounis Syndrome Complicated by Eosinophilic Myocarditis

Kounis syndrome is a rare but life-threatening form of coronary vasospasm, defined by the co-occurrence of acute coronary syndrome and hypersensitivity reaction. We present a case of refractory coronary vasospasm with aborted sudden cardiac arrest secondary to type 1 Kounis syndrome, which was complicated by eosinophilic myocarditis and cardiogenic shock. A 29-year-old Hispanic woman with history of vasospastic angina, presented with recurrent episodes of angina at rest. Initial evaluation revealed hyper-eosinophilia, elevated troponin and diffuse ST segment depression on electrocardiogram (ECG). Suddenly, she developed bradycardia and had a sudden cardiac arrest. An urgent coronary angiogram after resuscitation revealed severe multifocal vasospasm which resolved following high doses of intracoronary vasodilators. Type 1 Kounis syndrome was suspected and she was initiated on intravenous corticosteroids and anti-histamines. Subsequently, she developed cardiogenic shock, and a cardiac magnetic resonance imaging (cMRI) showed diffuse subendocardial late gadolinium enhancement (LGE) suggestive of eosinophilic myocarditis. She was diagnosed with type 1 Kounis syndrome associated with eosinophilic myocarditis. Kounis syndrome should be suspected in patients with refractory vasospastic angina. When indicated, coronary angiography should be performed with administration of intracoronary vasodilators for diagnostic and therapeutic purposes. Although, definite diagnosis of eosinophilic myocarditis requires endomyocardial biopsy, cMRI can be a crucial non-invasive method for establishing the diagnosis.

Coronary Artery Spasm as Related to Anxiety and Depression: A Nationwide Population-Based Study

OBJECTIVE

Anxiety and depression are risk factors for obstructive coronary artery disease (CAD), but their effects on coronary artery spasm (CAS) remain unestablished.

METHODS

Patient records in this population-based study were retrospectively collected from the Taiwan National Health Insurance Research Database. Using propensity score matching, we used 1:1:1 ratio stratification into a control group of 10,325 individuals without CAS or CAD, a CAS group comprising 10,473 patients, and a CAD group comprising 10,473 patients during 2000-2012.

RESULTS

The prevalence of CAS and CAD was 0.067% and 8.7%, respectively, in the general population. The prevalence of anxiety and depression diagnoses was significantly higher in patients with new-onset CAS than in those with new-onset CAD and controls without CAS/CAD, even after propensity score matching. Compared with CAD, anxiety and depression diagnoses conferred a higher risk of developing CAS (odds ratio [OR] = 2.29, 95% confidence interval [CI], 2.14-2.45, p < .001, and OR = 1.34, 95% CI, 1.08-1.66, p = .007, respectively). The association was even stronger when comparing CAS with the control group without CAD or CAS (OR = 5.20, 95% CI, 4.72-5.74, p < .001, and OR = 1.98, 95% CI, 1.50-2.62, p < .001, respectively). The increased risk of new-onset CAS as related to previous anxiety and depression diagnoses was comparable between males and females.

CONCLUSIONS

Compared with CAD or the general population, anxiety and depression diagnoses confer a higher risk of developing CAS. No sex differences are found for the association of anxiety and depression with CAS.

Omalizumab induced Takotsubo syndrome: case report

Background

Omalizumab is a humanized monoclonal anti-immunoglobulin E antibody, approved for the treatment of spontaneous chronic urticaria, with high efficacy and an excellent safety profile. Although its adverse effects are rare, allergic reactions and cardiovascular events were previously described.

Case summary

The authors describe the case of a 75-year-old woman, followed at the outpatient dermatology clinic due to spontaneous chronic urticaria, treated with omalizumab 300 mg every 4 weeks. After the 11th administration of omalizumab, the patient developed an episode of thoracalgia associated with electro- and echocardiographic abnormalities. Coronary angiogram excluded coronary artery disease, and left ventriculography demonstrated mid-apical akinesia and basal hyperkinesia, consistent with the Takotsubo syndrome (TS).

Discussion

Takotsubo syndrome was already reported in association with other monoclonal antibodies. However, to our knowledge, this is the first case of TS following the administration of omalizumab.

A comprehensive clinical diagnostic score system for prediction of coronary artery spasm in patients with acute chest pain

Background

Currently, there is no validated multivariate model to predict probability of coronary artery spasm (CAS) in patients with acute chest pain.

Methods

A total of 976 consecutive patients with acute chest pain were enrolled. Patients were divided into two groups based on the presence of significant CAS. To adjust potential confounders, a multivariable analysis was performed and a clinical diagnostic score system for CAS was utilized for score derivation.

Results

Multivariable analysis model selected 6 predictors for CAS. The integer score was assigned to each predictors: angina at rest alone (10 points), positive of hyperventilation test (8 points), allergies (3 points), asthma, ST-segment elevation and myocardial bridge (2 points each). We showed that the clinical diagnostic score system had accuracy in predicting CAS, as measured by the area under the curve (AUC), which was 0.952–0.966. The cut-off baseline value for the clinical diagnostic score system was set to 11–12 points with specificity of 91.0–93.3% and sensitivity of 90.7–92.9%, respectively.

Conclusion

A clinical diagnostic score system was derived and validated as an accurate tool for estimating the pretest probability of CAS in patients with acute chest pain.

Ivabradine for coronary artery disease and/or heart failure-a protocol for a systematic review of randomised clinical trials with meta-analysis and Trial Sequential Analysis

BACKGROUND

Coronary artery disease and heart failure are both highly prevalent diseases with a global prevalence of 93 million and 40 million. These patients are at increased risk of morbidity and mortality. The management of these patients involves medical therapy, and both diseases can be treated using the heart rate-lowering drug ivabradine. However, the evidence regarding the use of ivabradine in the treatment of coronary artery disease and/or heart failure is unclear. Our objective is to assess the beneficial and harmful effects of ivabradine in the treatment of coronary artery disease and/or heart failure.

METHODS

This protocol for a systematic review was undertaken using the recommendations of The Cochrane Collaboration, the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols (PRISMA-P), and the eight-step assessment procedure suggested by Jakobsen and colleagues. We plan to include all relevant randomised clinical trials assessing the use of ivabradine in the treatment of coronary artery disease and/or heart failure. We will search the Cochrane Central Register of Controlled Trials (CENTRAL), Medical Literature Analysis and Retrieval System Online (MEDLINE), Excerpta Medica database (EMBASE), Latin American and Caribbean Health Sciences Literature (LILACS), Science Citation Index Expanded on Web of Science, Chinese Biomedical Literature Database (CBM), China National Knowledge Infrastructure (CNKI), Chinese Science Journal Database (VIP), and BIOSIS in order to identify relevant trials. We will begin the searches in February 2019. All included trials will be assessed and classified at low risk of bias or at high risk of bias. Our primary conclusions will be based on the results from the primary outcomes at low risk of bias. Extracted data will be analysed using Review Manager 5.3 and Trial Sequential Analysis 0.9.5.10. We will create a 'Summary of Findings' table in which we will present our primary and secondary outcomes, and we will assess the quality of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE).

DISCUSSION

The systematic review will have the potential to aid clinicians in decision-making regarding ivabradine and to benefit patients with coronary artery disease and/or heart failure.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018112082.

Association of East Asian Variant Aldehyde Dehydrogenase 2 Genotype (ALDH2*2*) with Coronary Spasm and Acute Myocardial Infarction

Coronary spasm plays an important role in the pathogenesis of ischemic heart disease, including angina pectoris, acute myocardial infarction (AMI), silent myocardial ischemia, and sudden death. The prevalence of coronary spasm is higher among East Asians probably due to genetic as well as environmental factors. ALDH2 eliminates toxic aldehydes including 4-hydroxy-2-nonenal (4-HNE) derived from lipid peroxidation and acrolein in tobacco smoking as well as ethanol-derived acetaldehyde and thereby protects tissues and cells from oxidative damage. Deficient variant ALDH2*2 genotype is prevalent among East Asians and is a significant risk factor for both coronary spasm and AMI through accumulation of toxic aldehydes, thereby contributing to oxidative stress, endothelial damage, vasoconstriction, and thrombosis. Toxic aldehydes are thus identified as risk factors to be targeted for the treatment of coronary spasm and AMI.

Acute Coronary Syndrome With Normal Coronary Arteries: a Case of Spontaneous Spasm Lysis

Introduction

Patients suffering from Myocardial Infarction with Non-Obstructive Coronary Arteries (MINOCA) are found with no obstructive coronary artery disease on coronary arteriography. The Aim of this interesting case report is to present a patient with acute chest pain, temporal ST-segment elevation and MINOCA.

Case report

A case of a young woman who presented with acute chest pain suggestive of angina, with temporal ST-segment elevation, accidentally recorded and not rising of myocardial necrosis biomarkers in blood tests is described. A coronary angiography via right radial artery was performed and revealed normal coronary arteries. She was defined suffering from Myocardial infarction with Non-Obstructive Coronary Arteries (MINOCA) which occurs in 1–14% of Myocardial Infarction cases. Treatment with nitrates calcium, calcium channel blockers and antiplatelet in the basis of ACS is highly indicated.

Conclusion

Coronary artery spasm is not a rare cause of ACS. Coronary angiography is indicated in all cases to exclude severe coronary heart disease

Increased plasma xanthine oxidoreductase activity deteriorates coronary artery spasm

Increased reactive oxygen species (ROS) contributes to the development of endothelial dysfunction, which is involved in coronary artery spasm (CAS). Xanthine oxidoreductase (XOR) plays a pivotal role in producing both uric acid and ROS. However, the association between plasma XOR activity and CAS has not been elucidated. The aim of this study was to investigate whether plasma XOR activity is associated with CAS. We measured XOR activity in 104 patients suspected for CAS, who presented without significant coronary artery stenosis and underwent intracoronary acetylcholine provocation tests. CAS was provoked in 44 patients and they had significantly higher XOR activity as compared with those without CAS. The patients were divided into three groups based on the XOR activity. The prevalence rate of CAS was increased with increasing XOR activity. A multivariate logistic regression analysis showed that the 3rd tertile group exhibited a higher incidence of CAS as compared with the 1st tertile group [odds ratio (OR) 6.9, P = 0.001) and the 2nd tertile group (OR 3.2, P = 0.033) after adjustment for conventional CAS risk factors, respectively. The C index was significantly improved by the addition of XOR activity to the baseline model based on CAS risk factors. Furthermore, the 3rd tertile group had the highest incidence of severe spasm defined as total obstruction, flow-limiting stenosis, diffuse spasm, multivessel spasm, and/or lethal arrhythmia. This is a first report to elucidate the association of plasma XOR activity with CAS. Increased plasma XOR activity is significantly associated with CAS.

Left Main Coronary Artery Diverticulum: Case Report and Review of the Literature

Coronary artery disease is a major cause of morbidity and mortality, and while most commonly is atherosclerotic, it can present with variable manifestations, both congenital and acquired. One such manifestation is coronary aneurysm, which is a localized dilatation of a coronary artery wall segment to greater than 1.5 times the adjacent normal segments. While a dilated outpouching of a coronary artery has been commonly classified as a coronary aneurysm, a non-dilated outpouching is rare and is referred to as a diverticulum, with only one previous case report in the literature. It is conceivable that other cases of coronary artery diverticulum may have been previously reported as an aneurysm, given the overlapping angiographic appearance. We present a case of a 72-year-old female patient with an incidental finding of left main coronary artery diverticulum on diagnostic coronary angiogram done for preoperative liver transplantation evaluation.

Activation of the monocytic α7 nicotinic acetylcholine receptor modulates oxidative stress and inflammation-associated development of coronary artery spasm via a p38 MAP-kinase signaling-dependent pathway

OBJECTIVE

Smoking and high-sensitivity C-reactive protein (hs-CRP) are risk factors for coronary artery spasm (CAS), which is characterized by the increased interleukin-6 (IL-6) level and monocyte counts; however, limited data are available regarding the role of cigarette-embedded nicotine in the modulation of monocytic inflammatory activity in CAS.

APPROACH

We investigated and elucidated the putative roles and associations of nicotine, monocytic IL-6, α7 nicotinic acetylcholine receptor (α7-nAChR), and CRP in CAS development.

RESULTS

We demonstrated that a significantly increased α7-nAChR (p = 0.001) and IL-6 (p = 0.0036) messenger RNA (mRNA) expression in the serum of patients with CAS. Serum hs-CRP levels exhibited a strong positive correlation with the monocytic mRNA expression of α7-nAChR (r = 0.71, p < 0.001) and IL-6 (r = 0.49, p = 0.006). The α7-nAChR and IL-6 expression levels of the CAS group were also positively correlated (r = 0.63, p < 0.001). Compared with the untreated controls, THP-1 cells and patient-derived monocytes treated with different concentrations of CRP displayed significantly increased expression levels of α7-nAChR mRNA and protein (p = 0.0054), in a dose-dependent manner. We also demonstrated that compared with the IL-6 expression elicited by CRP alone (p = 0.0489), the CRP-induced rise in monocytic IL-6 mRNA and protein expression in the presence of nicotine (p = 0.0002), is mediated by α7-nAChR activation and the deregulation of the human p38 mitogen-activated protein kinases (MAPK) signaling pathway.

CONCLUSIONS

Our data demonstrate that the elevated monocytic IL-6 and α7-nAChR mRNA and protein expression levels are associated with the interaction between nicotine and CRP positively modulates CAS development. Our study suggests the potential role of α7-nAChR mRNA and/or protein expression as a diagnostic biomarker for CAS.

Coronary artery spasm due to intravenous atropine infusion in a child: possible Kounis syndrome

Coronary vasospasm can result from silent myocardial ischaemia to sudden death. There are many precipitant factors including different pharmacological agents. Kounis syndrome is defined by acute coronary syndromes associated with anaphylactic or anaphylactoid reactions. We report, to the best of our knowledge, the first paediatric case of Kounis syndrome due to intravenous atropine.

Coronary Microcirculatory Dysfunction in Human Cardiomyopathies: A Pathologic and Pathophysiologic Review

Cardiomyopathies are a heterogeneous group of diseases of the myocardium. The term cardiomyopathy involves a wide range of pathogenic mechanisms that affect the structural and functional states of cardiomyocytes, extravascular tissues, and coronary vasculature, including both epicardial coronary arteries and the microcirculation. In the developed phase, cardiomyopathies present with various clinical symptoms: dyspnea, chest pain, palpitations, swelling of the extremities, arrhythmias, and sudden cardiac death. Due to the heterogeneity of cardiomyopathic patterns and symptoms, their diagnosis and therapies are great challenges. Despite extensive research, the relation between the structural and functional abnormalities of the myocardium and the coronary circulation are still not well understood in the various forms of cardiomyopathy. The main pathological characteristics of cardiomyopathies and the coronary microcirculation develop in a progressive manner due to (1) genetic-immunologic-systemic factors; (2) comorbidities with endothelial, myogenic, metabolic, and inflammatory changes; (3) aging-induced arteriosclerosis; and (4) myocardial fibrosis. The aim of this review is to summarize the most important common pathological features and/or adaptations of the coronary microcirculation in various types of cardiomyopathies and to integrate the present understanding of the underlying pathophysiological mechanisms responsible for the development of various types of cardiomyopathies. Although microvascular dysfunction is present and contributes to cardiac dysfunction and the potential outcome of disease, the current therapeutic approaches are not specific for the given types of cardiomyopathy.

Variant Angina and Aborted Sudden Cardiac Death

PURPOSE OF REVIEW

Variant angina, which is characterized by recurrent chest pain and transient ECG changes along with angiographic evidence of coronary artery spasm, generally has a favorable prognosis. However, episodes of ischemia caused by vasospasm may lead to potentially life-threatening ventricular arrhythmias and cardiac arrest, even in patients with no history of prior cardiac disease. This review describes the epidemiology, pathogenesis, clinical spectrum, and management of variant angina, as well as outcomes in patients who present with aborted sudden cardiac death (ASCD).

RECENT FINDINGS

Contrary to prior opinions, evidence from recent observational studies indicate that patients with variant angina presenting with ASCD face a worse prognosis than those without this type of presentation. Predictors of ASCD include age, hypertension, hyperlipidemia, family history of sudden cardiac death, multi-vessel spasm, and left anterior descending artery spasm. Medical therapy alone with calcium channel blockers and nitrates may not be sufficiently protective in these patients and there is lack of concrete data on the optimal management strategy. Current guidelines recommend implantable cardiac defibrillator (ICD) therapy in patients who are survivors of cardiac arrest caused by ventricular fibrillation or unstable ventricular tachycardia after reversible causes are excluded, and should strongly be considered in these patients. Although medical therapy is absolutely imperative for patients with variant angina and a history of ASCD, ICD therapy in these patients is justified. Further large-scale studies are required to determine whether ICD therapy can improve survival in this high-risk group of patients.

Long-term outcomes of a Caucasian cohort presenting with acute coronary syndrome and/or out-of-hospital cardiac arrest caused by coronary spasm

BACKGROUND

Coronary artery spasm may be the underlying mechanism in up to 10% of cases of acute coronary syndrome (ACS) and sudden cardiac death. Asian individuals exhibit a 3-times greater incidence of spasm than Caucasians; this is likely due to different types of mechanisms. Consequently, solid data is limited about the long-term prognosis in Caucasian patients presenting with ACS and/or out-of-hospital cardiac arrest (OHCA) caused by coronary spasm.

METHODS

Between 2002 and 2015, thirty Caucasian patients with coronary artery spasm presenting with ACS (N = 29) and/or OHCA (N = 11) were enrolled in this prospective registry. Follow-up, consisting of regular outpatient visits, was conducted with a mean follow-up period of 7.5 ± 3.3 years. Outcomes included presence of stable angina pectoris, recurrence of ACS, occurrence of implantable cardioverter defibrillator (ICD) shocks and death.

RESULTS

The majority of patients (60%) remained asymptomatic during the entire follow-up period. At the end of the follow-up period only 3 patients still experienced stable angina (10%). Only 2 patients (7%) had a recurrent cardiac event, in which the ICD provided appropriate shock therapy. Half of the patients treated with stenting (N = 6), required re-interventions.

CONCLUSION

Coronary spasm with ACS and/or OHCA in a Caucasian patient cohort has a relatively benign prognosis in the majority of patients in long-term follow-up, if treated appropriately with medical therapy. Both the role of ICD in OHCA secondary to coronary spasm, and the efficacy of stenting to treat vasospastic angina, warrant further study in large-sized prospective clinical trials.

Spontaneous Left Main and Right Coronary Artery Spasm in a Patient With Vasospastic Angina

Coronary spasm is a well-documented, though rare, condition that can mimic myocardial infarction and is usually found in only a single vessel during an event. We describe the case of a 43-year-old male with past medical history of hypertension, hyperlipidemia, tobacco abuse, and with no known coronary disease. The patient developed chest pain 3 days postadmission for primary diagnosis of psychiatric disorder. The patient had a positive stress study with moderate reversible ischemia in the anterolateral region. A subsequent coronary angiography was performed that revealed significant left main coronary obstruction with TIMI I (thrombolysis in myocardial infarction) flow. This pattern was also present in the proximal right coronary artery. Both stenoses were relieved with intracoronary nitroglycerin, revealing no significant obstructive disease and TIMI III flow. The patient was started on dihydropyridine calcium channel blocker and counseled against smoking without recurrence of angina.

Aberrant coronary artery spasms cause ST-T segment depression during endovascular ablation of atrial flutter

ST‐T segment depression during right‐sided endovascular catheter ablation is not only caused by obstructive coronary artery disease or (induced) tachycardia. Clinicians should also consider coronary artery spasms evoked by manipulation of nearby catheters, especially in patients with abnormal coronary artery anatomy.

Long-term spironolactone treatment reduces coronary TRPC expression, vasoconstriction, and atherosclerosis in metabolic syndrome pigs

Coronary transient receptor potential canonical (TRPC) channel expression is elevated in metabolic syndrome (MetS). However, differential contribution of TRPCs to coronary pathology in MetS is not fully elucidated. We investigated the roles of TRPC1 and TRPC6 isoforms in coronary arteries of MetS pigs and determined whether long-term treatment with a mineralocorticoid receptor inhibitor, spironolactone, attenuates coronary TRPC expression and associated dysfunctions. MetS coronary arteries exhibited significant atherosclerosis, endothelial dysfunction, and increased histamine-induced contractions. Immunohistochemical studies revealed that TRPC6 immunostaining was significantly greater in the medial layer of MetS pig coronary arteries compared to that in Lean pigs, whereas little TRPC6 immunostaining was found in atheromas. Conversely, TRPC1 immunostaining was weak in the medial layer but strong in MetS atheromas, where it was predominantly localized to macrophages. Spironolactone treatment significantly decreased coronary TRPC expression and dysfunctions in MetS pigs. In vivo targeted delivery of the dominant-negative (DN)-TRPC6 cDNA to the coronary wall reduced histamine-induced calcium transients in the MetS coronary artery medial layer, implying a role for TRPC6 in mediating calcium influx in MetS coronary smooth muscles. Monocyte adhesion was increased in Lean pig coronary arteries cultured in the presence of aldosterone; and spironolactone antagonized this effect, suggesting that coronary mineralocorticoid receptor activation may regulate macrophage infiltration. TRPC1 expression in atheroma macrophages was associated with advanced atherosclerosis, whereas medial TRPC6 upregulation correlated with increased histamine-induced calcium transients and coronary contractility. We propose that long-term spironolactone treatment may be a therapeutic strategy to decrease TRPC expression and coronary pathology associated with MetS.

Acute Vision Loss Following Endoscopic Sinus Surgery

A 41-year-old female with a history of uterine cancer and Celiac and Raynaud's Disease presented to our institution with frequent migraines and nasal congestion. She underwent functional endoscopic sinus surgery (FESS) and experienced acute unilateral vision loss postoperatively. Rapid recognition of the etiology and effective treatment are paramount given the permanent and irreversible vision loss that can result. Arterial vasospasm following FESS is rare. Patients with autoimmune diseases have perhaps an increased risk for vasospasm secondary to an increased vasoreactive profile. We present the first documented case of nitroglycerin sublingual therapy to successfully treat ophthalmic artery vasospasm following FESS. Nitroglycerin sublingual therapy is a promising treatment for ophthalmic vasospasm secondary to its ability to cross the blood-ocular barrier, its rapid onset of action, and its ability to promote relaxation of vascular smooth muscle.

Fluctuations in the amplitude of ST-segment elevation in vasospastic angina: Two case reports

RATIONALE

ST-segment elevation localizes an ischemic lesion to the coronary artery supplying the area of the myocardium reflected by the electrocardiographic leads. Dynamic ST-segment elevation can be due to severe transmural ischemia secondary to a thrombus, vasospasm, or a tightly fixed coronary artery lesion or a combination of these situations.

PATIENT CONCERNS

In this study, we report on two patients with angina who had fluctuations in ST-segment amplitude on serial electrocardiograms. The amplitude of ST-segment elevation varied between 1-20 mm.

DIAGNOSES

Vasospastic angina (VSA) was diagnosed based on electrocardiography and coronary angiography.

INTERVENTIONS

Calcium antagonists were prescribed for both patients.

OUTCOMES

No recurrent VSA was noted during outpatient follow-up.

LESSONS

VSA can be associated with fluctuations in the amplitude of ST-segment elevation, indicating dynamic coronary vasospasm in different locations and extensions in patients with VSA.

Assessment of the Anti-anginal Effect of Tetramethylpyrazine Using Vasopressin-Induced Angina Model Rats

Intravenous tetramethylpyrazine has been widely used in China as a complementary and/or alternative medicine to treat patients with ischemic heart disease. We assessed the anti-anginal effect of tetramethylpyrazine (10 mg/kg, intravenously (i.v.), n=6) in comparison with that of its vehicle, saline (1 mL/kg, i.v., n=6), using vasopressin-induced angina model rats. First, Donryu rats were anesthetized with pentobarbital sodium (60 mg/kg, intraperitoneally (i.p.)), and the surface lead I electrocardiogram was continuously monitored. Administration of vasopressin (0.5 IU/kg, i.v.) to the rats depressed the S-wave level of the electrocardiogram, indicating the onset of subendocardial ischemia. However, pretreatment with tetramethylpyrazine suppressed the vasopressin-induced depression of the S-wave level, which was not observed following pretreatment with its vehicle alone (saline), suggesting that tetramethylpyrazine ameliorated the vasopressin-induced subendocardial ischemia in vivo. These results may provide experimental evidence for the empirically known clinical efficacy of tetramethylpyrazine against ischemic heart disease, and could provide clues to better understanding its in vivo mechanism of action.

Prinzmetals Angina Masquerading as Acute Pericarditis

Coronary artery spasm is an intense vasoconstriction of the coronary arteries and may be responsible for the myocardial ischemia, myocardial infarction as well as sudden deaths. Coronary angiography is generally needed to identify the cause. Coronary artery spasm is a multifactorial disease with underlying mechanism still poorly understood. Here, we present case of a 48-year-old male with no significant past history who presented with acute episodic onset chest pain. Clinical, Electrocardiography (ECG) and echocardiographic findings suggested pericarditis but a diagnostic coronary angiography revealed significant coronary vasospasm. Patient's symptoms significantly improved with calcium channel blockers and Nitroglycerine (NTG).

Spontaneous multi-focal coronary artery spasm: a case report

Spontaneous coronary artery vasospasm is one of the important causes of acute chest pain syndromes. The diagnosis of diffuse multifocal spasm can be quite challenging and it could be easily mistaken for diffuse coronary artery disease. The use of intracoronary nitroglycerin can relieve spasm and reveal the real extent of coronary artery disease. Herein we present a case presenting with acute myocardial infarction due to severe coronary artery spasm that had even received fibrinolytic therapy. Multiple narrowing was shown during coronary angiography and the patient was scheduled for percutaneous coronary intervention (PCI). But after intracoronary (IC) injection of nitroglycerin, all of lesions disappeared completely and the diagnosis of coronary spasm was confirmed.

Noninvasive detection of coronary vasospastic angina using a double-acquisition coronary CT angiography protocol in the presence and absence of an intravenous nitrate: a pilot study

OBJECTIVES

To evaluate the feasibility of a double-acquisition coronary CT angiography (CCTA) protocol in the presence and absence of an intravenous (IV) vasodilator infusion for detecting vasospastic angina.

METHODS

Twenty patients with a high clinical probability of vasospastic angina were enrolled. All subjects underwent baseline CCTA without a vasodilator in the early morning followed by a catheterized coronary angiography with ergonovine provocation test. Within 3 days, all subjects underwent repeat CCTA during a continuous IV infusion of nitrate. Vasospastic angina as detected by CCTA was defined as significant stenosis (≥50 %) with negative remodelling without definite plaques or diffuse small diameter (<2 mm) of a major coronary artery with a beaded appearance on baseline CT that completely dilated on IV nitrate CT. The CCTA results were compared to the catheterized ergonovine provocation test as the reference standard.

RESULTS

Among 20 patients, the catheterized ergonovine provocation test detected vasospasm in 15 patients. The sensitivity, specificity, positive predictive value and negative predictive value of CCTA in a per-patient-based analysis were 73, 100, 100 and 56 %, respectively.

CONCLUSIONS

Double-acquisition CCTA in the presence and absence of IV infusion of nitrate allows noninvasive detection of vasospastic angina with moderate sensitivity and high specificity.

KEY POINTS

• Limited data exist regarding the efficacy of CCTA in detecting vasospastic angina. • We propose a double-acquisition CCTA protocol with and without IV nitrate injections. • This protocol provides 100% specificity and moderate sensitivity (73%) in spasm detection.

Stress cardiomyopathy: Is it limited to Takotsubo syndrome? Problems of definition

In 2006, Takotsubo syndrome (TTC) was described as a distinct type of stress-induced cardiomyopathy (stress cardiomyopathy). However, when thinking about Takotsubo cardiomyopathy from the viewpoints of the AHA and ESC classifications, 2 possible problems may arise. The first potential problem is that a forecast of disease outcome is lacking in the ESC classification, whereas the AHA only states that 'outcome is favorable with appropriate medical therapy'. However, based on the literature data, one can make a general conclusion that occurrence of myocardial lesions in TTC (i.e., myocardial fibrosis and contraction-band necrosis) causes the same effects as in other diseases with similar levels of myocardial damage and should not be considered to have a lesser impact on mortality. To summarise, TTC can cause not only severe complications such as pulmonary oedema, cardiogenic shock, and dangerous ventricular arrhythmias, but also damage to the myocardium, which can result in the development of potentially fatal conditions even after the disappearance of LV apical ballooning. The second potential problem arises from the definition of TTC as a stress cardiomyopathy in the AHA classification. In fact, the main factors leading to TTC are stress and microvascular anginas, since, as has been already discussed, coronary spasm can cause myocardium stunning, resulting in persistent apical ballooning. Thus, based on this review, 3 distinct types of stress cardiomyopathies exist (variant angina, microvascular angina, and TTC), with poor prognosis. Adding these diseases to the classification of cardiomyopathies will facilitate diagnosis and preventive prolonged treatment, which should include intensive anti-stress therapy.