Coronary Artery Spasm: New Insights

Unusual Recurrent Multivessel Coronary Artery Spasm: A Case Report and Literature Review

Coronary artery spasms (CAS) can manifest in various forms, from silent ischemia to severe cardiac events like myocardial infarction and sudden death. This case involves a 56-year-old male with recurrent ischemic chest pain and varying ECG signs. Cardiac catheterization revealed multiple coronary spasms that resolved spontaneously or with intracoronary nitroglycerin. The report emphasizes the severe presentations of multiple CAS and the importance of thorough diagnostic evaluation to avoid unnecessary interventions, highlighting the diagnostic challenges in managing such cases.

Patent Foramen Ovale and Coronary Artery Spasm: A New Patent Foramen Ovale-associated Condition that May Explain the Mechanism of Vasospastic Angina

Patent foramen ovale (PFO) may be an underlying factor in the pathogenesis of migraine, vasospastic angina, and Takotsubo cardiomyopathy. This article reviews the role that PFO may play in each of these clinical entities and discusses potential interventions. It also proposes a novel clinical syndrome wherein PFO may be the unifying link among migraine, coronary vasospasm, and Takotsubo cardiomyopathy in predisposed individuals.

The association between fibrinogen-to-albumin ratio and adverse prognosis in patients with myocardial infarction with non-obstructive coronary arteries

BACKGROUND

The fibrinogen-to-albumin ratio (FAR) has been identified as a new inflammatory marker for predicting the risk of cardiovascular diseases. Nevertheless, its prognostic relevance in patients with myocardial infarction with non-obstructive coronary arteries (MINOCA) remains uncertain.

METHODS

This study included a total of 1031 hospitalized patients diagnosed with MINOCA, enrolled consecutively. The primary outcome was the occurrence of major adverse cardiovascular events (MACE). Based on the median FAR value, patients were divided into high FAR (FARH) and low FAR (FAR-L) groups. Baseline clinical characteristics and the incidence of adverse events during the follow-up period were compared between the two groups. Various statistical methods were applied, including restricted cubic spline modeling, Kaplan-Meier survival analysis, and Cox proportional hazards modeling.

RESULTS

The median follow-up duration was 42.3 months, during which 157 patients (15.2 %) experienced MACE. The FAR-H group had a significantly higher incidence of MACE compared to the FAR-L group (21.2 % vs. 9.3 %, p < 0.001). Multivariate Cox regression analysis revealed that a higher FAR was an independent predictor of long-term MACE in MINOCA patients (hazard ratio = 2.76, 95 % confidence interval: 1.95-3.89, p < 0.001), after adjusting for relevant clinical variables.

CONCLUSIONS

An elevated FAR is linked to a poor long-term prognosis in patients with MINOCA.

Quantitative analysis of three-dimensional choroidal changes in coronary artery disease patients with swept-source optical coherence tomography angiography

PURPOSE

To quantitatively analyze three-dimensional (3D) choroidal changes in coronary artery disease (CAD) patients with swept-source optical coherence tomography angiography (SS-OCTA) based on a scan area of 12×12mm.

METHODS

236 CAD patients and 78 controls were included after coronary angiography (CAG) evaluation in this prospective cross-sectional study. Choroidal and foveal avascular zone (FAZ) parameters were compared between the two groups. Choroidal morphological characteristics were also evaluated based on ETDRS quadrants. Receiver operating characteristics (ROC) curves were generated to determine the discriminative power of choroidal and FAZ parameters. Linear regression analysis was used to determine the relationships between Gensini score and choroidal parameters.

RESULTS

Choroidal thickness (CT), choroidal vascular volume/ area (CVV/a), and choroidal stromal volume/ area (CSV/a) were significantly reduced in CAD patients, while 2D vascular density decreased only in 1-6 mm, and no statistical difference in choroidal vascularity index (CVI) values was detected. The AUC values of choroidal parameters were greater in the inner-6 mm area than the outer-6 mm area, and good performance was found with a combination with FAZ parameters (AUC=0.77, P < 0.001). For morphological analysis, both groups showed the greatest values in superior quadrant and the lowest in nasal quadrant. After controlling for confounding factors, Gensini score was negatively associated with CT (β = -0.35, P = 0.003), CVV/a (β = -0.17, P = 0.004), and CSV/a (β = -0.18, P = 0.005).

CONCLUSION

The SS-OCTA provided excellent visualization and quantification of the choroid and showed decreased choroidal thickness and volume in CAD patients, but the morphological features were unchanged. The severity of coronary artery stenosis was independently associated with choroidal changes.

Familial catamenial coronary spasms

Coronary artery spasms represent important causes of myocardial ischaemia and infarction in patients with non-obstructive coronary artery disease. They are notably seen in younger people and occur almost equally in men and women. Besides traditional risk factors (ie, smoking), female hormones might also play a role.We report of two young sisters who presented with myocardial infarction caused by catamenial coronary spasms (CS), that is, during menstruation. In one of these women, this resulted in heart failure with a severely reduced ejection fraction and ultimately a heart transplant because of intractable ventricular arrhythmias.CS might result from changing hormone levels (especially oestrogen) during menstruation. Increased awareness of the occurrence of catamenial CS is essential for diagnosis and consequent treatment with coronary vasodilators and/or specific oestrogen/progesterone regimens.

Ischaemia with no obstructive coronary arteries: a review with focus on the Asian population

ABSTRACT

Ischaemia with no obstructive coronary arteries (INOCA) has been a diagnostic and therapeutic challenge for decades. Several studies have demonstrated that INOCA is associated with an increased risk of death, adverse cardiovascular events, poor quality of life and high healthcare cost. Although there is increasing recognition of this entity in the Western population, in the Asian population, INOCA remains elusive and its prevalence uncertain. Despite its prognostic significance, diagnosis of INOCA is often delayed. In this review, we identified the multiple barriers to its diagnosis and management, and proposed strategies to overcome them.

Association of the interleukine-6 polymorphism with catheter-induced coronary artery spasm in Egyptians

BACKGROUND

The role of coronary artery spasm (CAS) was extended beyond variant angina to ischemic heart disease in general, including effort angina, unstable angina, acute myocardial infarction (MI) and sudden death. It is difficult and cumbersome to examine CAS during coronary angiography. Risk factors for CAS include smoking and genetic polymorphisms.

AIM

We aimed to investigate the association of the interleukin-6 (IL-6) polymorphism with catheter-induced CAS in Egyptian patients who undergo coronary angiography.

METHODS

This is a case-control study. Two hundred patients with chronic coronary artery disease who underwent elective coronary angiography were included in the study. Patients were divided into two groups: the non-CAS group (100 patients) and the CAS group (100 patients). The subjects were genotyped to the -572 C>G (rs 1800796) polymorphism of the IL-6 gene by PCR-restriction fragment length polymorphism.

RESULTS

We found that patients with CAS have more risk factors for atherosclerosis compared to those without CAS. Smoking, the IL-6 GG genotype, and the G allele were independent risk factors for CAS.

CONCLUSION

We concluded that the GG genotype and G allele of the IL-6 gene are associated with CAS. Smoking, the GG genotype, and the G allele of the IL-6 gene are independent predictors of catheter-induced CAS.

Phosphorylated CPI-17 and MLC2 as Biomarkers of Coronary Artery Spasm-Induced Sudden Cardiac Death

Coronary artery spasm (CAS) plays an important role in the pathogeneses of various ischemic heart diseases and has gradually become a common cause of life-threatening arrhythmia. The specific molecular mechanism of CAS has not been fully elucidated, nor are there any specific diagnostic markers for the condition. Therefore, this study aimed to examine the specific molecular mechanism underlying CAS, and screen for potential diagnostic markers. To this end, we successfully constructed a rat CAS model and achieved in vitro culture of a human coronary-artery smooth-muscle cell (hCASMC) contraction model. Possible molecular mechanisms by which protein kinase C (PKC) regulated CAS through the C kinase-potentiated protein phosphatase 1 inhibitor of 17 kDa (CPI-17)/myosin II regulatory light chain (MLC2) pathway were studied in vivo and in vitro to screen for potential molecular markers of CAS. We performed hematoxylin and eosin staining, myocardial zymogram, and transmission electron microscopy to determine myocardial and coronary artery injury in CAS rats. Then, using immunohistochemical staining, immunofluorescence staining, and Western blotting, we further demonstrated a potential molecular mechanism by which PKC regulated CAS via the CPI-17/MLC2 pathway. The results showed that membrane translocation of PKCα occurred in the coronary arteries of CAS rats. CPI-17/MLC2 signaling was observably activated in coronary arteries undergoing CAS. In addition, in vitro treatment of hCASMCs with angiotensin II (Ang II) increased PKCα membrane translocation while consistently activating CPI-17/MLC2 signaling. Conversely, GF-109203X and calphostin C, specific inhibitors of PKC, inactivated CPI-17/MLC2 signaling. We also collected the coronary artery tissues from deceased subjects suspected to have died of CAS and measured their levels of phosphorylated CPI-17 (p-CPI-17) and MLC2 (p-MLC2). Immunohistochemical staining was positive for p-CPI-17 and p-MLC2 in the tissues of these subjects. These findings suggest that PKCα induced CAS through the CPI-17/MLC2 pathway; therefore, p-CPI-17 and p-MLC2 could be used as potential markers for CAS. Our data provide novel evidence that therapeutic strategies against PKC or CPI-17/MLC2 signaling might be promising in the treatment of CAS.

Recurrent cardiac arrest and complete atrioventricular block due to idiopathic coronary vasospasm: A case report

Recurrent complete atrioventricular block induced by coronary spasm is rare. We present a case of a 47-year-old woman who suffered from two episodes of out-of-hospital cardiac arrest within one year due to complete atrioventricular block caused by coronary vasospasm. No implantable cardioverter defibrillator was implanted after her first episode. As for the second episode, permanent brain injury was left behind despite successful cardiopulmonary resuscitation. She underwent a challenging rehabilitation process and an implantable cardioverter defibrillator was implanted before discharge. We captured the dynamic changes of the electrocardiogram during the episode with high temporal resolution. This case illustrates the importance of recognizing coronary spasm as a potential cause of complete atrioventricular block and highlights the need for implantable cardioverter defibrillator in such patients to improve survival and quality of life.

A New Syndrome of Patent Foramen Ovale Inducing Vasospastic Angina and Migraine

Patent foramen ovale (PFO) is the most common congenital cardiac abnormality and is usually considered a benign finding. This case series suggests a potential link between PFO and vasospastic angina. It also demonstrates PFO closure as a potential therapeutic intervention for individuals with PFO who suffer from refractory vasospastic angina.

A Case of Aborted Sudden Cardiac Death Due to Coronary Artery Spasm

Coronary artery spasm remains an important yet rarely recognized cause of myocardial ischemia, which may manifest as vasospastic angina, ventricular arrhythmia, or sudden cardiac death. Here we present a case of ST-segment elevation myocardial infarction complicated by cardiac arrest secondary to coronary artery spasm, diagnosed with invasive coronary function testing.

Acute Myocardial Infarction: Etiologies and Mimickers in Young Patients

Acute myocardial infarction is an important cause of death worldwide. While it often affects patients of older age, acute myocardial infarction is garnering more attention as a significant cause of morbidity and mortality among young patients (<45 years of age). More specifically, there is a focus on recognizing the unique etiologies for myocardial infarction in these younger patients as nonatherosclerotic etiologies occur more frequently in this population. As such, there is a potential for delayed and inaccurate diagnoses and treatments that can carry serious clinical implications. The understanding of acute myocardial infarction manifestations in young patients is evolving, but there remains a significant need for better strategies to rapidly diagnose, risk stratify, and manage such patients. This comprehensive review explores the various etiologies for acute myocardial infarction in young adults and outlines the approach to efficient diagnosis and management for these unique patient phenotypes.

Spontaneous Coronary Sinus Thrombosis Detected by Point-of-care Transthoracic Echo: A Case Report

INTRODUCTION

Coronary sinus thrombosis (CST) is a rare condition, primarily occurring after instrumentation of the heart, with no prior reported cases diagnosed via point-of-care ultrasound or of spontaneous occurrence without predisposing medical or surgical history. Patients typically present with critical illness, and CST has a reported mortality of 80%.

CASE REPORT

We present a case of a healthy 38-year-old male with chest pain one hour after cocaine use, with an electrocardiogram pattern consistent with Wellens syndrome, whose point-of-care cardiac ultrasound revealed CST.

CONCLUSION

This uncommon ultrasonographic finding has never been reported in the emergency medicine literature to our knowledge. It can be recognized by the clinician sonographer during standard point-of-care transthoracic echocardiogram.

Diltiazem is a useful and effective medication for reversal of coronary artery spasm-induced complete atrioventricular block: A case report

Coronary artery spasm (CAS) is characterized by reversible diffuse or focal vasoconstriction, a phenomenon that plays an important role in the pathogenesis of ischemic heart disease. Fatal arrhythmias, such as ventricular tachycardia/fibrillation and complete atrioventricular block (AV-B), are very common in patients with CAS. Nondihydropyridine calcium channel blockers (CCBs) such as diltiazem were recommended as first-line medications for treating and preventing CAS episodes. However, its use remains controversial in CAS patients with AV-B as this type of CCB can also cause AV-B itself. Here, we present the use of diltiazem in a patient with complete AV-B caused by CAS. The patient's chest pain was rapidly relieved, and complete AV-B was promptly restored to sinus rhythm following the administration of intravenous diltiazem without any adverse effects. In this report, we highlight the useful and effective application of diltiazem for treating and preventing complete AV-B caused by CAS.

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.

Impaired retinal microcirculation in patients with non-obstructive coronary artery disease

PURPOSE

To quantitatively investigate alterations of retinal microcirculation in patients with non-obstructive coronary artery disease (NOCAD) using optical coherence tomography angiography (OCTA), and to identify the ability of retinal microcirculation parameters in differentiating coronary artery disease (CAD) subtypes.

METHODS

All participants with angina pectoris underwent coronary computed tomography angiography. Patients with lumen diameter reduction of 20-50 % in all major coronary arteries were defined as NOCAD, while patients with at least one major coronary artery lumen diameter reduction ≥ 50 % were recruited as obstructive coronary artery disease (OCAD). Participants without a history of ophthalmic or systemic vascular disease were recruited as healthy controls. Retinal neural-vasculature was measured quantitatively by OCTA, including peripapillary retinal nerve fiber layer (RNFL) thickness and vessel density (VD) of the optic disc, superficial vessel plexus (SVP), deep vessel plexus (DVP), and foveal density (FD 300). p < 0.017 is considered significant in multiple comparisons.

RESULTS

A total of 185 participants (65 NOCAD, 62 OCAD, and 58 controls) were enrolled. Except for the DVP fovea (p = 0.069), significantly reduced VD in all other regions of SVP and DVP was detected in both the NOCAD and OCAD groups compared to control group (all p < 0.017), while a more significant decrease was found in OCAD compared to NOCAD. Multivariate regression analysis showed that lower VD in superior hemi part of whole SVP (OR: 0.582, 95 % CI: 0.451-0.752) was an independent risk factor for NOCAD compared to controls, while lower VD in the whole SVP (OR: 0.550, 95 % CI: 0.421-0.719) was an independent risk factor for OCAD compared to NOCAD. Using the integration of retinal microvascular parameters, the area under the receiver operating characteristic curve (AUC) for NOCAD versus control and OCAD versus NOCAD were 0.840 and 0.830, respectively.

CONCLUSION

Significant retinal microcirculation impairment, while milder than that in OCAD was observed in NOCAD patients, indicating retinal microvasculature assessment might provide a new systemic microcirculation observation window for NOCAD. Furthermore, retinal microvasculature may serve as a new indicator to assess the severity of CAD with good performance of retinal microvascular parameters in identifying different CAD subtypes.

Simultaneous total occlusion due to spasm of 2 main coronary arteries: A case report

RATIONALE

Coronary artery spasm (CAS) defined by severe reversible focal or diffuse vasoconstriction, plays an essential role in the pathophysiology of acute coronary syndrome but is not very common in the clinic. Due to its transience, it is difficult to diagnose CAS directly, many patients are diagnosed by clinical experience. Here, we report the diagnosis and treatment of a rare case of simultaneous total occlusion due to spasm of the two main coronary arteries by coronary angiography (CAG).

PATIENT CONCERNS

A 47-year-old man with no medical history was admitted to our emergency room complaining of sudden-onset chest pain lasting 3 hours. Emergency CAG showed total occlusion of the proximal left anterior descending artery and right coronary artery.

DIAGNOSES

Acute myocardial infarction caused by CAS was diagnosed, according to CAG findings and test results.

INTERVENTIONS

Intracoronary injection of nitroglycerin and anti-spasm medication.

OUTCOMES

The patient was discharged on the 8th day with complete resolution of symptoms and normalization of the electrocardiography findings. No ischemic events occurred during a follow-up for 27 months.

LESSONS

This case highlights the significance of identifying CAS in patients with acute myocardial infarction and avoiding blind interventional stent therapy, which requires closer attention from clinicians.

Case report: A rare manifestation of vasospasm induced myocardial infarction with ST-segment elevation in a young male patient

Background

Minority of acute myocardial infarctions (MI) are caused by a non-atherosclerotic occlusion of the coronary artery. We present a case report, where MI with ST-segment elevation was provoked by a vasospasm, which is a rare aetiological finding.

Case presentation

27-year-old male patient presented to the emergency department because of a sudden onset chest pain radiating to the left arm. The patient underwent percutaneous coronary intervention (PCI) to the right coronary artery (RCA) 3 months ago due to inferior wall MI, however, chest pain episodes kept on recurring at night throughout the whole period after the intervention. During current admission, initial electrocardiogram (ECG) demonstrated ST-segment elevation in leads II, III and aVF. Coronary angiogram revealed diffuse severe narrowing of the right coronary artery, which was relieved with intracoronary administration of nitrates and verapamil. After coronary angiogram patient was given oral long-acting nitrates and verapamil, however, during the following days nocturnal chest pain episodes reoccurred. It was decided to swap verapamil to diltiazem, which led to complete cessation of angina episodes. The patient was discharged in stable condition and symptom free. It was suspected that the first MI was of vasospastic origin, which likely led to unnecessary stenting.

Conclusions

This clinical case has demonstrated the challenges clinician could face in order to correctly diagnose vasospasm-induced MI because of its rare occurrence and highly variable presentation. We strongly suggest using intracoronary nitroglycerine during coronary angiography as a standard practice to avoid a potential diagnostic error and unnecessary stenting. Although, in some cases the reason behind coronary artery spasm (CAS) remains unclear, medical treatment can be very effective for CAS prevention.

Coronary artery spasm treated with intracoronary bioresorbable scaffold implantation under the guidance of treadmill test and optical coherence tomography: A case report

Coronary artery spasm (CAS) can cause unstable angina, and the treatment of this disease is controversial. We report an elderly male patient who was admitted to hospital due to chest tightness. CAG showed that 70% stenosis in the middle of the right coronary artery (RCA). A bioresorbable scaffold (BRS) was implanted in the lesion under the guidance of optical coherence tomography (OCT). One year later, the patient's symptoms were relieved. The repeated CAG showed that the stent was good. BRS implantation under the guidance of treadmill test and OCT is one of treatment options for CAS patients.

Myocardial Infarction with Non-Obstructive Coronary Arteries: A Puzzle in Search of a Solution

Background

The term myocardial infarction with non-obstructive coronary arteries (MINOCA), defines a puzzling event occurring in the absence of obstructive coronary artery disease on coronary angiography and without an overt potential cause. However, a practical diagnostic work-up is often difficult, due to the heterogeneous etiologies and pathophysiology of MINOCA. This review aims to provide a comprehensive overview focusing on epidemiology, etiopathogenesis, diagnostic tools and therapeutic strategies for subjects with MINOCA, in order to provide a prompt and accurate diagnostic work-up and an adequate therapeutic approach in this subset population.

Methods

This educational review was carried out by following the standard methods of the Cochrane Collaboration and the PRISMA statement. The terms "MINOCA" OR ("myocardial infarction" AND ("non-obstructive" OR "non-obstructive")) were searched in PubMed and Embase databases (in Title and/or Abstract) from 1st January 2003 until 31st May 2022.

Results

Etiologic findings, clinical presentation and the degree of hemodynamic impairment play a pivotal role in defining the patient's natural history and prognostic outcome, and may significantly impact on the decision-making strategies and therapeutic approaches.

Conclusions

Despite further advances in diagnostic and therapeutic strategies, MINOCA remains a challenging conundrum in clinical practice. Clinicians should be aware of the different potential etiologies and pathogenic mechanisms of MINOCA, in order to carry out a comprehensive diagnostic work-up and implement a tailored therapeutic approach.

Cellular Mechanisms of Coronary Artery Spasm

Coronary artery spasm (CAS) is a reversible phenomenon caused by spontaneous excessive vascular smooth muscle contractility and vascular wall hypertonicity, which results in partial or complete closure of the lumen of normal or atherosclerotic coronary arteries. The clinical picture of CAS includes chest discomfort which is similar in quality to that of stable effort angina. Mechanisms underlying the development of CAS are still unclear. CAS certainly is a multifactorial disease. In this review, we paid attention to the role of the main pathophysiologic mechanisms in CAS: endothelial dysfunction, chronic inflammation, oxidative stress, smooth muscle hypercontractility, atherosclerosis and thrombosis, and mutations leading to deficient aldehyde dehydrogenase 2 (ALDH2) activity. These findings might shed novel insight on the underlying mechanisms and identify potential diagnostic and therapeutic targets for cardiovascular diseases in the future.

Intracoronary injection of nitroglycerine can prevent unnecessary percutaneous coronary intervention

Background

Despite the recommendation of the current guidelines, intracoronary administration of nitroglycerine during coronary angiography is often neglected. We investigated the effect of intra-coronary nitroglycerin on the relief of coronary artery stenosis in the candidates for percutaneous coronary intervention (PCI).

Methods

We included patients with angina pectoris or myocardial infarction who were candidates for PCI. In the coronary angiography, the culprit vessel involved was evaluated, and bolus nitroglycerin at a dose of 25–200 mcg was injected into the affected coronary artery. A significant change in the percentage of coronary artery stenosis was considered a positive response, and these patients were then compared with patients who did not have a substantial change in the percentage of stenosis at the same time. Univariate analysis and then multivariate logistic regression analysis was performed to determine the predictors of response to intracoronary nitroglycerin.

Results

Among 360 patients, 27 (7.5%) responded to nitroglycerine, and 333 (92.5%) were non-responsive. The mean age of patients was 60.2 ± 11.6 years, ranging from 23 to 93 years, and 265 (73.6%) were men. The study groups were not significantly different in the baseline demographic characteristics. The presence of multivessel disease (Odds ratio (OR) = 16.26, 95% confidence interval (CI):2.07–127.6; P = 0.008) and stenosis in the left circumflex artery (OR = 3.62, 95% CI: 1.03–12.70; P = 0.044) were the independent predictors for nonresponse to nitroglycerine, leading to PCI.

Conclusion

In some cases, especially those without multivessel diseases, intracoronary nitroglycerine administration can efficiently relieve coronary stenosis and prevent unnecessary PCI.

Acute Coronary Syndrome in Patients with SARS-CoV-2 Infection: Pathophysiology and Translational Perspectives

Acute coronary syndromes (ACS) may complicate the clinical course of patients with Coronavirus Disease 2019 (COVID-19). It is still unclear whether this condition is a direct consequence of the primary disease. However, several mechanisms including direct cellular damage, endothelial dysfunction, in-situ thrombosis, systemic inflammatory response, and oxygen supply-demand imbalance have been described in patients with COVID-19. The onset of a prothrombotic state may also be facilitated by the endothelial dysfunction secondary to the systemic inflammatory response and to the direct viral cell damage. Moreover, dysfunctional endothelial cells may enhance vasospasm and platelet aggregation. The combination of these factors promotes atherosclerotic plaque instability, thrombosis and, consequently, type 1 myocardial infarction. Furthermore, severe hypoxia due to extensive pulmonary involvement, in association with other conditions described in COVID-19 such as sepsis, tachyarrhythmias, anemia, hypotension, and shock, may lead to mismatch between oxygen supply and demand, and cause type 2 myocardial infarction. A deeper understanding of the potential pathophysiological mechanisms underlying ACS in patients with COVID-19 could help the therapeutic management of these very high-risk patients.

Coronary functional assessment in non-obstructive coronary artery disease: Present situation and future direction

Non-obstructive coronary artery disease (CAD), which is defined as coronary stenosis <50%, has been increasingly recognized as an emerging entity in clinical practice. Vasomotion abnormality and coronary microvascular dysfunction are two major mechanisms contributing to the occur of angina with non-obstructive CAD. Although routine coronary functional assessment is limited due to several disadvantages, functional evaluation can help to understand the pathophysiological mechanism and/or to exclude specific etiologies. In this review, we summarized the potential mechanisms involved in ischemia with non-obstructive coronary arteries (INOCA) and myocardial infarction with non-obstructive coronary arteries (MINOCA), the two major form of non-obstructive CAD. Additionally, we reviewed currently available functional assessment indices and their use in non-obstructive CAD. Furthermore, we speculated that novel technique combined anatomic and physiologic parameters might provide more individualized therapeutic choice for patients with non-obstructive CAD.

Rapid identification of source of delayed hemobilia following endoscopic metallic stenting for malignant biliary obstruction

Delayed hemobilia, a rare but potentially fatal complication of endoscopic metallic stenting for malignant biliary obstruction, requires prompt identification of the source of bleeding and subsequent embolization. However, hemobilia is characteristically intermittent, and computed tomography (CT) often fails to show pseudoaneurysms or extravasations. In particular, because the posterior superior pancreaticoduodenal artery (PSPDA) runs alongside the common bile duct for its whole length, it is readily obscured by metallic artifacts in that duct, such as stents, making identification of the source of bleeding by CT difficult. We have encountered three patients with delayed hemobilia from the PSPDA following endoscopic biliary stenting for malignant biliary obstruction in whom no extravasation or pseudoaneurysms were detected by contrast-enhanced CT during bleeding. However, when we identified that the PSPDA had a smaller diameter than in previous CTs in all three cases, we suspected that the PSPDA was the source of the bleeding. No extravasation or pseudoaneurysms were detected with celiac arteriography or superior mesenteric arteriography; however, extravasation and pseudoaneurysms were detected by direct PSPDA angiography. Hemostasis was achieved through embolization. Detecting a large decrease in the diameter of the PSPDA on contrast-enhanced CT during biliary bleeding may help to identify the source of that bleeding.

Myocardial bridging is significantly associated to myocardial infarction with non-obstructive coronary arteries

BACKGROUND

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is a common disorder characterized by the presence of clinical criteria for acute myocardial infarction in the absence of obstructive coronary artery disease on angiography. We aim to investigate the relationship between myocardial bridging (MB) and MINOCA.

METHODS AND RESULTS

An observational retrospective study was conducted on 15 036 patients who had been referred for coronary angiography and who fulfilled the Fourth Universal Definition of Myocardial Infarction. The study population was divided into ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation myocardial infarction (NSTEMI) patients, from which we defined two main groups: the MINOCA group and the coronary artery disease (CAD) group. Statistical analyses were carried out by using SPSS, version 20. The prevalence of angiographic MB among the groups was significantly greater in the MINOCA group (2.9% vs. 0.8%). MINOCA accounted for 14.5% of spontaneous myocardial infarction, and the clinical presentation was more frequently NSTEMI rather than STEMI (84.3% vs. 15.7%). After adjusting for confounders, multivariate analyses showed a positive association between MB and MINOCA [odds ratio = 3.28, 95% CI (2.34; 4.61) P < 0.001]. Cardiovascular risk factors were less common in the MINOCA population, which was younger and more often female.

CONCLUSION

MB is a risk factor for MINOCA. Because MB prevalence differed significantly between the controls (CAD group) and cases (MINOCA group), which were positively associated to MB, it seems likely that MB would be a potential cause of MINOCA. Investigations for MB in MINOCA cases and especially in NSTEMI patients seem necessary.

Coronary Artery Spasm: Risk Factors, Pathophysiological Mechanisms and Novel Diagnostic Approaches

Coronary artery spasm (CAS) is a transient reversible subtotal or complete occlusion induced by coronary hypercontraction and the critical cause of myocardial ischaemia with non-obstructive coronary arteries. During the past decades, our knowledge of the risk factors and pathophysiological mechanisms of CAS have been increasingly progressed, and various diagnostic approaches, including imaging technologies and novel biomarkers, have been proposed to serve well to diagnose CAS clinically. This review aims to summarize these research progresses on the risk factors of CAS and introduce current knowledge about the mechanisms accounting for CAS, including endothelial dysfunction, vascular smooth muscle cell hyperreactivity, and adventitial and perivascular adipose tissue inflammation. We also gathered the recently evolved diagnostic approaches and analyzed their advantages/disadvantages, in purpose of enhancing the diagnostic yield on the basis of ensuring accuracy.

Evaluation of MINOCA syndrome and HEART score in patients presenting to the emergency department with panic attack and chest pain complaints

BACKGROUND

Patients presenting with chest pain may or may not be experiencing a panic attack. Is chest pain caused by a panic attack or myocardial infarction with non-obstructive coronary arteries (MINOCA) syndrome?

AIM

In this study, we evaluated both MINOCA syndrome and HEART score in patients who presented to the emergency department with panic attacks and chest pain.

METHOD

Patients who applied to the emergency department with panic disorder and chest pain complaints were included. Patients who met the MINOCA diagnostic criteria were identified. The study was completed with 143 eligible patients out of a total of 217 patients evaluated. The patients were divided into two groups. The first group was those whose symptoms and test results were consistent with MINOCA. The second group was composed of those whose chest pain was considered non-specific. The HEART score of all patients was calculated. The demographic characteristics, symptoms, and HEART scores were compared between the groups.

RESULTS

Of the 143 patients evaluated in the study, 62 (43.3%) were male and 81 (56.7%) were female. While the mean HEART score was 4.7 ± 1.5 in the MINOCA group, it was 2.0 ± 1.0 in the non-cardiac group, a statistically significant difference.

CONCLUSION

Clinicians should pay attention to the patient's age, gender, number of attacks per week, HEART score, and which symptoms (palpitations, shortness of breath, and fear of death) are present in patients who meet the panic attack diagnostic criteria. Clinicians should be alert to the MINOCA syndrome in panic attack patients.

Perioperative coronary artery spasm after off-pump coronary artery bypass grafting in the non-manipulated coronary artery

BACKGROUND

Perioperative coronary artery spasm (CAS) following coronary artery bypass grafting (CABG) is a severe or lethal condition that is rarely reported. In addition, rare cases with CAS following CABG in the non-manipulated coronary artery are angiographically documented in the perioperative period. We aimed to report our experiences on the diagnosis and treatment of a case with CAS following off-pump CABG in the non-manipulated coronary artery.

METHODS

A 57-year old male with coronary heart disease and unstable angina willing to undergo CABG was admitted to our department. CABG was recommended as he showed 90% stenosis in distal left anterior descending artery, 90% stenosis in intermediate branch, 90% stenosis in left circumflex coronary artery, as well as 50% stenosis in proximal right coronary artery (RCA).

RESULTS

After CABG, the patient showed Adams-Stokes syndrome and ST-segment elevation. Then CPR was conducted and coronary angiography indicated perioperative CAS in the non-manipulated posterior descending artery. For the treatment, the patient received nitroglycerin injection into the coronary artery by catheter and pumping of diltiazem. Finally, the patient was discharged on day 7 after surgery. A comprehensive literature search was conducted to summarize the studies focused on the diagnosis and treatment of such condition, which indicated that all of the CAS cases occurred in the manipulated vessels, except one study showing CAS in the untouched native coronary artery which was similar with our case.

CONCLUSIONS

Perioperative CAS in the non-manipulated coronary artery following CABG is a severe or lethal condition that is rarely reported, which deserves close attention by the clinicians in clinical practice.

Pathophysiologic Basis and Diagnostic Approaches for Ischemia With Non-obstructive Coronary Arteries: A Literature Review

Ischemia with non-obstructive coronary arteries (INOCA) has gained increasing attention due to its high prevalence, atypical clinical presentations, difficult diagnostic procedures, and poor prognosis. There are two endotypes of INOCA-one is coronary microvascular dysfunction and the other is vasospastic angina. Diagnosis of INOCA lies in evaluating coronary flow reserve, microcirculatory resistance, and vasoreactivity, which is usually obtained via invasive coronary interventional techniques. Non-invasive diagnostic approaches such as echocardiography, single-photon emission computed tomography, cardiac positron emission tomography, and cardiac magnetic resonance imaging are also valuable for assessing coronary blood flow. Some new techniques (e.g., continuous thermodilution and angiography-derived quantitative flow reserve) have been investigated to assist the diagnosis of INOCA. In this review, we aimed to discuss the pathophysiologic basis and contemporary and novel diagnostic approaches for INOCA, to construct a better understanding of INOCA evaluation.

Severe coronary artery spasm during left atrial appendage closure plus catheter ablation for atrial fibrillation: case presentation

Background

Left atrial appendage closure (LAAC) combined with radiofrequency catheter ablation (RFCA) as a hybrid procedure is commonly performed to treat atrial fibrillation (AF). Although this treatment carries a low risk of coronary artery spasm (CAS), and has never been observed in LAAC procedure, caution still needed to be taken. We presented a case of CAS that occurred in an AF patient during the hybrid procedure.

Case presentation

The patient was a 65-year-old man with paroxysmal AF who developed CAS during RFCA and LAAC. In this case, LAAC was performed ahead of RFCA. After atrial septal puncture, the occluder was advanced into left atrium through delivery sheath, and successfully deployed in the LAA. After verifying the assessment of “PASS” criteria, we decided to release the device. However, before releasing the occluder in LAAC, the patient’s blood pressure (BP) fell to 70/45 mmHg with heart rate (HR) drop and ST-segment elevation in II, III, and aVF and reciprocal ST-segment depression in I and aVL. Isotonic sodium chloride load was administered. After 3 min, the BP and HR raised, and ST-segment returned to normal. The occluder was successfully released after the stable condition of the patient. Then, RFCA was sequentially performed. When isolating the right pulmonary veins, the patient’s BP and HR fell again with ST-segment elevation in inferior leads. Spontaneous ventricular tachycardia and fibrillation developed rapidly and defibrillation was performed immediately with success. Coronary angiography revealed the obstruction of the right coronary artery which disappeared completely after intracoronary nitroglycerin injection (1 mg). Under systemic diltiazem infusion, the RFCA procedure was accomplished. After the procedure, the patient recovered without any neurologic deficit, and CAS has never recurred with isosorbide mononitrate treatment during follow-up.

Conclusions

CAS is a rare complication associated with AF hybrid procedure. Attention should be paid to this rare but potentially life-threatening complication.

Isa WYH. An Evaluation of the Role of Oxidative Stress in Non-Obstructive Coronary Artery Disease

Approximately half of all women presenting to the emergency department with angina chest pain do not have obstructive coronary artery disease (CAD) on coronary angiography. This condition is termed non-obstructive coronary artery disease (NOCAD), and includes ischemia with no obstructive coronary artery disease (INOCA) and myocardial infarction with non-obstructive coronary arteries (MINOCA). Oxidative stress has been reported to be involved in the development and progression of CAD. However, a scarcity of studies has assessed a correlation between oxidative stress and NOCAD. Thus, a literature review was performed of available reports on the role of oxidative stress in NOCAD. Possible mechanisms involved in oxidative stress that may contribute to NOCAD were identified and evaluated. A key finding of this literature review was that oxidative stress caused vasoconstriction and endothelial damage, and this results in coronary microvascular dysfunction and vasospasm, which, in turn, lead to the pathogenesis of NOCAD.

Fisetin, a major component derived from mulberry (Morus australis Poir.) leaves, prevents vascular abnormal contraction

Mulberry (Morus australis Poir.) leaves have long been consumed in the form of tea or tincture especially in Asia, owing to their high antioxidant and blood pressure-regulating properties. Although it is thought that vascular abnormal contraction may be involved in the blood pressure-suppressing effect, the effect of mulberry on vascular abnormal contraction is still unknown. Therefore, we investigated mulberry leaves as a potential source of bioactive compounds that prevent vascular abnormal contraction. Mulberry leaves were divided into fresh leaves and tea leaves and further classified according to the age of the tree: more or less than 20 years old, into roasted and unroasted. Mulberry fruits were also evaluated. We assessed the preventive effect of mulberry extracts on vascular abnormal contraction. Extracts from mulberry leaves of trees more than 20 years old showed a strong preventive effect on vascular abnormal contraction of human coronary artery smooth muscle cells. Therefore, to identify the active components in mulberry leaves, we fractionated the active fractions by gel filtration chromatography and reversed-phase high-performance liquid chromatography. The active fraction was further analyzed by mass spectrometry and nuclear magnetic resonance; an active component of the mulberry leaf extract was fisetin. In addition, our results indicated that the hydroxyl group at the C-3 position of fisetin is crucial for its activity. These results prove that fisetin is effective in preventing vascular abnormal contraction. Overall, mulberry leaves and fisetin are expected to be used in a wide range of fields such as functional foods, nutraceuticals, and drug targets.

Remifentanil pretreatment ameliorates H/R-induced cardiac microvascular endothelial cell dysfunction by regulating the PI3K/Akt/HIF-1α signaling pathway

Restoration of blood supply through medical or surgical intervention is a commonly adopted method for acute myocardial ischemia, but is also a trigger for cardiac ischemia/reperfusion injury. Studies have shown that remifentanil (REM) displays cardioprotective effects. In this study, the effects of REM on HCMEC viability were examined before and after the induction of H/R using Cell Counting Kit-8 assays. Wound healing and Matrigel angiogenesis assays were performed to assess HCMEC migration and angiogenesis, respectively. Commercial kits and western blotting were used to determine the endothelial barrier function of H/R-stimulated HCMECs with or without REM treatment. The expression of PI3K/Akt/hypoxia-inducible factor-1α (HIF-1α) pathway-related proteins was detected by western blotting. After pre-treatment with PI3K/Akt, the effects of REM on H/R-induced HCMEC injury were examined. We found that pre-treatment with REM displayed no impact on HCMEC viability under normal conditions but noticeably improved cell viability following H/R. The migratory abilities and tube-like structure formations of H/R-stimulated HCMECs were both enhanced by REM in a concentration-dependent manner. REM also decreased the permeability of H/R-stimulated HCMECs and upregulated the expression of tight junction proteins. Furthermore REM increased the expression of PI3K/Akt/HIF-1α signaling-related proteins in HCMECs. Inhibition of PI3K/Akt rescued REM-enhanced HCMEC function under H/R condition. Therefore, the present study demonstrated that REM pretreatment ameliorated H/R-induced HCMEC dysfunction by regulating the PI3K/Akt/HIF-1α signaling pathway.

Coronary artery aneurysm: A review

Coronary artery aneurysm (CAA) is a clinical entity defined by a focal enlargement of the coronary artery exceeding the 1.5-fold diameter of the adjacent normal segment. Atherosclerosis is the main cause in adults and Kawasaki disease in children. CAA is a silent progressive disorder incidentally detected by coronary angiography, but it may end with fatal complications such as rupture, compression of adjacent cardiopulmonary structures, thrombus formation and distal embolization. The pathophysiological mechanisms are not well understood. Atherosclerosis, proteolytic imbalance and inflammatory reaction are involved in aneurysmal formation. Data from previously published studies are scarce and controversial, thereby the management of CAA is individualized depending on clinical presentation, CAA characteristics, patient profile and physician experience. Multiple therapeutic approaches including medical treatment, covered stent angioplasty, coil insertion and surgery were described. Herein, we provide an up-to-date systematic review on the pathophysiology, complications and management of CAA.

Coronary vasospasm: A narrative review

Coronary artery vasospasm (CAVS) plays an important role in acute chest pain syndrome caused by transient and partial or complete occlusion of the coronary arteries. Pathophysiology of the disease remains incompletely understood, with autonomic and endothelial dysfunction thought to play an important role. Due to the dynamic nature of the disease, its exact prevalence is not entirely clear but is found to be more prevalent in East Asian and female population. Cigarette smoking remains a prominent risk factor, although CAVS does not follow traditional coronary artery disease risk factors. Many triggers continue to be identified, with recent findings identifying chemotherapeutics, allergens, and inflammatory mediators as playing some role in the exacerbation of CAVS. Provocative testing with direct visualization is currently the gold-standard for diagnosis, but non-invasive tests, including the use of biomarkers, are being increasingly studied to aid in the diagnosis. Treatment of the CAVS is an area of active research. Apart from risk factor modification, calcium channel blockers are currently the first line treatment, with nitrates playing an important adjunct role. High-risk patients with life-threatening complications should be considered for implantable cardioverter defibrillator (ICD), although timing criteria for escalated therapy require further investigation. The role of pharmaceuticals targeting oxidative stress remains incompletely understood.

COVID-19 and Acute Coronary Syndromes: From Pathophysiology to Clinical Perspectives

Acute coronary syndromes (ACS) are frequently reported in patients with coronavirus disease 2019 (COVID-19) and may impact patient clinical course and mortality. Although the underlying pathogenesis remains unclear, several potential mechanisms have been hypothesized, including oxygen supply/demand imbalance, direct viral cellular damage, systemic inflammatory response with cytokine-mediated injury, microvascular thrombosis, and endothelial dysfunction. The severe hypoxic state, combined with other conditions frequently reported in COVID-19, namely sepsis, tachyarrhythmias, anemia, hypotension, and shock, can induce a myocardial damage due to the mismatch between oxygen supply and demand and results in type 2 myocardial infarction (MI). In addition, COVID-19 promotes atherosclerotic plaque instability and thrombus formation and may precipitate type 1 MI. Patients with severe disease often show decrease in platelets count, higher levels of d-dimer, ultralarge von Willebrand factor multimers, tissue factor, and prolongation of prothrombin time, which reflects a prothrombotic state. An endothelial dysfunction has been described as a consequence of the direct viral effects and of the hyperinflammatory environment. The expression of tissue factor, von Willebrand factor, thromboxane, and plasminogen activator inhibitor-1 promotes the prothrombotic status. In addition, endothelial cells generate superoxide anions, with enhanced local oxidative stress, and endothelin-1, which affects the vasodilator/vasoconstrictor balance and platelet aggregation. The optimal management of COVID-19 patients is a challenge both for logistic and clinical reasons. A deeper understanding of ACS pathophysiology may yield novel research insights and therapeutic perspectives in higher cardiovascular risk subjects with COVID-19.

Prognostic value of statin therapy in patients with myocardial infarction with nonobstructive coronary arteries (MINOCA): a meta-analysis

BACKGROUND

Given the complex aetiology and a limited amount of evidence, the medical treatment (including statin use) of myocardial infarction with non-obstructive coronary artery disease (MINOCA) remains uncertain. The objective of the present study was to evaluate the effect of statin therapy on major cardiovascular events (MACE) and mortality in MINOCA patients.

METHODS

A systematic review and meta-analysis of time-to-event outcomes were performed of studies of statin therapy on MINOCA patients, reporting data from MACE or mortality, after searching the PubMed/MEDLINE, Embase, Science Direct, Scopus, Google Scholar, and Cochrane databases. A fixed-effects meta-analysis model was then applied.

RESULTS

Six observational studies of statin therapy on MINOCA, involving a total of 11,171 patients, were identified and considered eligible for analysis (9129 subjects received statin therapy while 2042 patients were part of the respective control arms). Quantitative analysis (5 studies were included) showed that statin use was associated with lower mortality (HR: 0.65; 95% CI: 0.56-0.75, I²: 0%). Also, the meta-analysis showed that statin therapy was associated with a lower incidence of MACE (HR: 0.78; 95% CI: 0.69-0.88, I²:27%).

CONCLUSION

Our data suggest that in a population with MINOCA, the use of statin therapy results in significant reduction on MACE and mortality. These results must be confirmed in future clinical trials.

Coronary Artery Spasm During Catheter Ablation Caused by the Intravenous Infusion of Isoproterenol

Radiofrequency ablation is an established treatment for atrial fibrillation (AF). However, coronary artery spasm (CAS) is a rare but a potentially lethal complication associated with this procedure. A 54-year-old man with paroxysmal AF underwent pulmonary vein isolation. The procedure was completed and AF could not be induced after burst pacing and the administration of isoproterenol. Suddenly, ST-segment elevation developed in the anterior leads and frequent premature ventricular contractions followed by non-sustained ventricular fibrillation. The diagnosis of CAS was made by urgent coronary angiography. We identified isoproterenol as a potential cause of CAS. Physicians should be aware of this potentially lethal side effect.