Provocative testing for coronary reactivity and spasm

Coronary microvascular disease in women: epidemiology, mechanisms, evaluation, and treatment

Coronary microvascular dysfunction (CMD) involves functional or structural abnormalities of the coronary microvasculature resulting in dysregulation of coronary blood flow (CBF) in response to myocardial oxygen demand. This perfusion mismatch causes myocardial ischemia, which manifests in patients as microvascular angina (MVA). CMD can be diagnosed non-invasively via multiple imaging techniques or invasively using coronary function testing (CFT), which assists in determining the specific mechanisms involving endothelium-independent and dependent epicardial and microcirculation domains. Unlike traditional coronary artery disease (CAD), CMD can often occur in patients without obstructive atherosclerotic epicardial disease, which can make the diagnosis of CMD difficult. Moreover, MVA due to CMD is more prevalent in women and carries increased risk of future cardiovascular events. Successful treatment of symptomatic CMD is often patient-specific risk factor and endotype targeted. This article aims to review newly identified mechanisms and novel treatment strategies for managing CMD, and outline sex-specific differences in the presentation and pathophysiology of the disease.

Idiopathic Ventricular Fibrillation - Just How Much Idiopathic is it?

Idiopathic ventricular fibrillation is diagnosed in survivors of sudden cardiac death that has been caused by ventricular fibrillation without known structural or electrical abnormalities, even after extensive investigation. It is a common cause of sudden death in young adults. Although idiopathic ventricular fibrillation is a diagnosis of exclusion, in many cases only a partial investigation algorithm is performed. The aim of this review is to present a comprehensive diagnostic evaluation algorithm with a focus on diagnostic assessment of inherited arrhythmic syndromes and genetic background.

A Case of Refractory Variant Angina

Coronary vasospasm is defined as the abnormal contraction of an epicardial coronary artery. Variant angina is a severe form of coronary vasospasm, reflecting transmural ischemia with ST-T elevation on an electrocardiogram. A pharmacologic spasm provocation test during coronary angiography is the gold standard evaluation for patients who have not been diagnosed with coronary vasospasm by a non-invasive test. The sensitivity and specificity of pharmacologic spasm provocation testing have been reported to be very high in patients with variant angina. Here, we report the case of a 61-year-old woman who had refractory variant angina. Although a pharmacologic spasm provocation test did not lead to a definitive diagnosis, she had recurrent acute coronary syndrome due to coronary vasospasm. Physicians should be aware of the limitations of the spasm provocation test, even in patients with refractory variant angina.

Insights into the invasive diagnostic challenges of coronary artery vasospasm - A systematic review

Coronary provocation testing is an essential diagnostic procedure when evaluating vasospastic angina. Invasive methods using acetylcholine or ergonovine are considered the current gold standard. Despite efforts from global cardiovascular institutions, current protocols vary in dosage, administration time, and procedural approach. In addition, concerns over the specificity of findings and potential complications have limited routine uptake of this procedure in clinical practice. This systematic review evaluates current diagnostic protocols, focusing on invasive provocation testing. We included studies using intracoronary provocation testing with acetylcholine or ergonovine for the assessment of coronary artery vasospasm that detailed specific elements of the procedure (dosage, administration time, etc.) and included ≥50 patients. A total of 28 articles met strict inclusion criteria. Our review highlights the heterogeneity between current diagnostic protocols for invasive provocation testing. We believe standardization of a diagnostic protocol will encourage both current and future cardiologists to incorporate such procedures in the evaluation of variant angina.

Coronary microvascular dysfunction and myocardial infarction with non-obstructive coronary arteries: Where do we stand?

In the past decade, scientific and clinical research has provided a translational perspective on myocardial infarction (MI) with non-obstructive coronary arteries (MINOCA). MINOCA is characterized by clinical documentation of an acute MI but angiography shows no significant coronary artery obstruction (stenosis <50%). The prevalence of MINOCA is estimated to range from approximately 6 to 10% among MI patients, and those with this condition have a poor prognosis, experiencing high rates of mortality, rehospitalization, and socioeconomic burden. MINOCA represents a major unmet need in cardiovascular medicine, with uncertain clinical management. It is a complex condition that can be caused by various factors, including atherosclerosis, plaque rupture, coronary vasospasm, and microvascular dysfunction. Effective management of MINOCA depends on identifying the underlying mechanism of the infarction, thus a systematic diagnostic approach is recommended. Contemporary data shows that a significant number of patients exhibit structural and functional abnormalities in coronary microcirculation, which is referred to as coronary microvascular dysfunction (CMD). CMD plays a crucial role in patients with signs and symptoms of myocardial ischemia and non-obstructive coronary artery stenosis, including MINOCA. Furthermore, conducting a thorough evaluation of coronary function can have significant prognostic and therapeutic implications, since personalized patient management strategies based on this assessment have been shown to improve symptoms and prognosis. Therefore, an accurate and timely diagnosis of CMD is essential for effective patient management, which can be achieved through various invasive and non-invasive methods. This review will discuss the pathophysiological understanding, current diagnostic techniques, and management strategies of patients with MINOCA and CMD.

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.

Sex-related differences in coronary vasomotor disorders: Comparisons between Western and Japanese populations

Sex-related differences in the prevalence of cardiac disorders have been elucidated beyond races. Angina/ischemia with nonobstructive coronary artery disease (AINOCA) is often observed in females. Coronary microvascular dysfunction (CMD) and coronary epicardial spasm (CES) are the principal cause of AINOCA. The clinical outcomes of Western patients with CMD were less satisfactory than expected, while the prognosis of Japanese patients with CES treated with medications including calcium channel blockers was favorable. However, the incidence and clinical features of coronary spasm endotypes were different between Western and Japanese populations. Furthermore, sex-related differences in the clinical manifestations and outcomes of patients with different spasm endotypes remain uncertain beyond race. In this article, we will review the sex differences in Japanese AINOCA patients with coronary vasomotor disorders, including CMD and CES, and compare them with those of Western patients.

Non-invasive diagnosis of vasospastic angina

Vasospastic angina (VSA), or variant angina, is an under-recognized cause of chest pain and myocardial infarction, especially in Western countries. VSA leads to a declined quality of life and is associated with increased morbidity and mortality. Currently, the diagnosis of VSA relies on invasive testing that requires the direct intracoronary administration of ergonovine or acetylcholine. However, invasive vasoreactivity testing is underutilized. Several non-invasive imaging alternatives have been proposed to screen for VSA. This review aims to discuss the strengths and limitations of available non-invasive imaging tests for vasospastic angina.

Myocardial infarction with non-obstructive coronary arteries (MINOCA)

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is evident in up to 15% of all acute myocardial infarctions (AMI) and disproportionally affects females. Despite younger age, female predominance, and fewer cardiovascular risk factors, MINOCA patients have a worse prognosis than patients without cardiovascular disease and a similar prognosis compared to patients with MI and obstructive coronary artery disease (CAD). MINOCA is a syndrome with a broad differential diagnosis that includes both ischemic [coronary artery plaque disruption, coronary vasospasm, coronary microvascular dysfunction, spontaneous coronary artery dissection (SCAD), and coronary embolism/thrombosis] and non-ischemic mechanisms (Takotsubo cardiomyopathy, myocarditis, and non-ischemic cardiomyopathy)-the latter called MINOCA mimickers. Therefore, a standardized approach that includes multimodality imaging, such as coronary intravascular imaging, cardiac magnetic resonance, and in selected cases, coronary reactivity testing, including provocation testing for coronary vasospasm, is necessary to determine underlying etiology and direct treatment. Herein, we review the prevalence, characteristics, prognosis, diagnosis, and treatment of MINOCA -a syndrome often overlooked.

Invasive Functional Coronary Assessment in Myocardial Ischemia with Non-Obstructive Coronary Arteries: from Pathophysiological Mechanisms to Clinical Implications

Despite ischemic heart disease (IHD) has been commonly identified as the consequence of obstructive coronary artery disease (OCAD), a significant percentage of patients undergoing coronary angiography because of signs and/or symptoms of myocardial ischemia do not have any significant coronary artery stenosis. Several mechanisms other than coronary atherosclerosis, including coronary microvascular dysfunction (CMD), coronary endothelial dysfunction and epicardial coronary vasospasm, can determine myocardial ischemia or even myocardial infarction in the absence of flow-limiting epicardial coronary stenosis, highlighting the need of performing adjunctive diagnostic tests at the time of coronary angiography to achieve a correct diagnosis. This review provides updated evidence of the pathophysiologic mechanisms of myocardial ischemia with non-obstructive coronary arteries, focusing on the diagnostic and therapeutic implications of performing a comprehensive invasive functional evaluation consisting of the assessment of both vasodilation and vasoconstriction disorders. Moreover, performing a comprehensive invasive functional assessment may have important prognostic and therapeutic implications both in patients presenting with myocardial ischemia with non-obstructive coronary arteries (INOCA) or myocardial infarction with non-obstructive coronary arteries (MINOCA), as the implementation of a tailored patient management demonstrated to improve patient's symptoms and prognosis. However, given the limited knowledge of myocardial ischaemia with non-obstructive coronary arteries, there are no specific therapeutic interventions for these patients, and further research is warranted aiming to elucidate the underlying mechanisms and risk factors and to develop personalized forms of treatment.

Safety and prognostic relevance of acetylcholine testing in patients with stable myocardial ischaemia or myocardial infarction and non-obstructive coronary arteries

BACKGROUND

Intracoronary provocation testing with acetylcholine (ACh) is crucial for the diagnosis of functional coronary alterations in patients with suspected myocardial ischaemia and non-obstructive coronary arteries.

AIMS

Our intention was to assess the safety and predictive value for major adverse cardiovascular and cerebrovascular events (MACCE) in patients presenting with ischaemia with non-obstructive coronary arteries (INOCA) or with myocardial infarction with non-obstructive coronary arteries (MINOCA).

METHODS

We prospectively enrolled consecutive INOCA or MINOCA patients undergoing intracoronary ACh provocation testing.

RESULTS

A total of 317 patients were enrolled: 174 (54.9%) with INOCA and 143 (45.1%) with MINOCA. Of these, 185 patients (58.4%) had a positive response to the ACh test. Complications during ACh provocative testing were all mild and transient and occurred in 29 (9.1%) patients, with no difference between patients with positive or negative responses to ACh testing, nor between INOCA and MINOCA patients. A history of paroxysmal atrial fibrillation, moderate/severe diastolic dysfunction and a higher QT dispersion at baseline electrocardiogram were independent predictors of complications. MACCE occurred in 30 patients (9.5%) during a median follow-up of 22 months. The incidence of MACCE was higher among patients with a positive ACh test (24 [13.0%] vs 6 [4.5%], p=0.017), and a positive ACh test was an independent predictor of MACCE.

CONCLUSIONS

ACh provocation testing is associated with a low risk of mild and transient complications, with a similar prevalence in both INOCA and MINOCA patients. Importantly, ACh provocation testing can help to identify patients at higher risk of future clinical events, suggesting a net clinical benefit derived from its use in this clinical setting.

Clinical Outcomes and Provoked Epicardial Spasm Phenotypes via Intracoronary Acetylcholine Testing in 680 Patients with Angina and Nonobstructive Coronary Arteries

Background: Epicardial spasm (ES) phenotypes may be related to the prognosis in patients with coronary spastic angina. Objectives: The purpose of this study was to elucidate the relationship between angiographic coronary vasomotor responses to intracoronary acetylcholine (ACh) injection and prognosis in patients with angina and nonobstructive coronary artery disease (ANOCAD). Methods: This was a retrospective, observational, single-center study of 680 patients with ANOCAD. ACh spasm provocation tests on both coronary arteries were performed without administering nitroglycerine to relieve provoked spasm in a first-attempt artery. ACh was injected in incremental doses of 20/50/100/200 μg into the left coronary artery and 20/50/80 μg into the right coronary artery. Positive ES was defined as ≥90% stenosis and usual chest pain and ischemic ECG changes. Results: Provoked positive ES was observed in 310 patients (46%), including 85 patients (13%) with focal spasm, 150 patients (22%) with diffuse spasm, and 75 patients (11%) with combined spasm (diffuse spasm and focal spasm), whereas the remaining 370 patients (54%) had no provoked spasm. An unclassified ACh test was observed in 186 patients (27%), while 184 patients (27%) had a complete negative ACh test. The clinical outcomes in patients with complete negative ES were satisfactory compared with those with positive ES and unclassified ACh test results. The prognosis in patients with an unclassified ACh test was not different from those with a positive ES. Furthermore, prognosis in patients with ES phenotypes was not different among the three groups. Conclusions: There was no correlation between provoked ES phenotypes via intracoronary ACh testing and prognosis in patients with ANOCAD; however, clinical outcomes in patients with positive ES and unclassified ACh tests were worse compared to those with complete negative ACh tests. We should focus on the treatments in patients with unclassified ACh tests as well as those with ESs.

MINOCA: One Size Fits All? Probably Not—A Review of Etiology, Investigation, and Treatment

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is a heterogeneous group of conditions that include both atherosclerotic (coronary plaque disruption) and non-atherosclerotic (spontaneous coronary artery dissection, coronary artery spasm, coronary artery embolism, coronary microvascular dysfunction, and supply–demand mismatch) causes resulting in myocardial damage that is not due to obstructive coronary artery disease. Failure to identify the underlying cause may result in inadequate and inappropriate therapy in these patients. The cornerstone of managing MINOCA patients is to identify the underlying mechanism to achieve the target treatment. Intravascular imaging is able to identify different morphologic features of coronary plaques, while cardiac magnetic resonance is the gold standard for detection of myocardial infarction in the setting of MINOCA. In this review, we summarize the relevant clinical issues, contemporary diagnosis, and treatment options of MINOCA.

Percutaneous coronary intervention in patients with documented coronary vasospasm during long-term follow-up

Objective

Although recurring coronary artery spasm (CAS) may lead to the development of fixed atherosclerotic coronary stenosis (FS), the relationship between coronary atherosclerosis and CAS is still speculative. We evaluated the incidence of FS requiring percutaneous coronary intervention (PCI) in patients with documented CAS during long-term follow-up and analysed their clinical features.

Methods

Clinical data of 3556 patients during a median follow-up of 9.4 years after non-invasive ergonovine spasm provocation testing with echocardiographic monitoring of left ventricular wall motion (erg echo) were analysed.

Results

Erg echo documented CAS in 830 (23.3%) patients, who had higher frequencies of coronary risk factors than those without CAS. Patients with documented CAS on erg echo showed significantly lower 10-year overall (90.5% vs 94.2%, p<0.001) and PCI-free (97.4% vs 98.4%, p=0.002) survival rates than those without CAS. Documented CAS was an independent factor associated with later PCI after adjustment by either Cox regression model or Fine-Gray competing risk model. There was no significant difference in baseline clinical characteristics between patients who needed later PCI and those who did not. Among 28 patients who needed later PCI after documentation of CAS, the original CAS and later PCI territory were concordant in 25 (89.3%), while 3 (10.7%) showed discordance.

Conclusions

CAS is a risk factor for the development of FS requiring PCI during long-term follow-up, and warrants physicians’ vigilance and careful follow-up of patients with documented CAS and insignificant stenosis of major epicardial coronary arteries at the time of initial diagnosis.

Ischemia and no obstructive coronary arteries in patients with stable ischemic heart disease

A large proportion of patients with suspected obstructive coronary artery disease (CAD) is found to have ischemia with no obstructive coronary artery disease (INOCA). Based on current evidence, these patients are at increased risk of adverse cardiovascular events, even though they have no obstructive CAD. Importantly, INOCA is associated with recurrent clinical presentations with chest pain, impaired functional capacity, reduced health-related quality of life, and high healthcare costs. Underlying coronary microvascular dysfunction (CMD), through endothelium-dependent and independent mechanisms contribute to these adverse outcomes in INOCA. While non-invasive and invasive diagnostic testing has typically focused on identification of obstructive CAD in symptomatic patients, functional testing to detect coronary epicardial and microvascular dysfunction should be considered in those with INOCA who have persistent angina. Current diagnostic methods to clarify functional abnormalities and treatment strategies for epicardial and/or microvascular dysfunction in INOCA are reviewed.

Coronary Microvascular Dysfunction Across the Spectrum of Cardiovascular Diseases: JACC State-of-the-Art Review

Coronary microvascular dysfunction (CMD) encompasses several pathogenetic mechanisms involving coronary microcirculation and plays a major role in determining myocardial ischemia in patients with angina without obstructive coronary artery disease, as well as in several other conditions, including obstructive coronary artery disease, nonischemic cardiomyopathies, takotsubo syndrome, and heart failure, especially the phenotype associated with preserved ejection fraction. Unfortunately, despite the identified pathophysiological and prognostic role of CMD in several conditions, to date, there is no specific treatment for CMD. Due to the emerging role of CMD as common denominator in different clinical phenotypes, additional research in this area is warranted to provide personalized treatments in this "garden variety" of patients. The purpose of this review is to describe the pathophysiological mechanisms of CMD and its mechanistic and prognostic role across different cardiovascular diseases. We will also discuss diagnostic modalities and the potential therapeutic strategies resulting from recent clinical studies.

Diltiazem Inhibits Coronary Spasm via Inhibition of Cav1.2Phosphorylation and Protein Kinase C Activation in a Mouse Model of Coronary Spastic Angina

Calcium antagonists are used for coronary spastic angina (CSA) treatment. We previously identified a phospholipase C (PLC) -δ1 gene variant that results in enhanced PLC activity in patients with CSA and developed a CSA animal model by generating vascular smooth muscle cell-specific human variant PLC-δ1 overexpression (PLC-TG) mice. In this study, we investigated the molecular mechanism of CSA using the PLC-TG mice and the inhibitory effect of a calcium antagonist, diltiazem hydrochloride (DL).We treated the PLC-TG and wild-type (WT) mice with oral DL or trichlormethiazide (TM) (control) for 2 weeks. Ergometrine injection-induced coronary spasm was observed on the electrocardiogram in all 5 PLC-TG mice treated with TM, but only in 1 of 5 PLC-TG mice treated with DL. Voltage-dependent calcium channel (Cav1.2) phosphorylation and protein kinase C (PKC) activity were enhanced in the aortas of PLC-TG mice treated with TM. DL treatment significantly inhibited Cav1.2 phosphorylation and PKC activity. Although total Cav1.2 expression was similar between WT and PLC-TG mice treated with TM, DL treatment significantly increased its expression in PLC-TG mice. Furthermore, its expression remained high after DL discontinuation. DL and PKC inhibitor suppressed intracellular calcium response to acetylcholine in cultured rat aortic smooth muscle cells transfected with variant PLC-δ1.These results indicate that enhanced PLC activity causes coronary spasm, presumably via enhanced Cav1.2 phosphorylation and PKC activity, both of which were inhibited by DL. Enhanced total Cav1.2 expression after DL discontinuation and high PKC activity may be an important mechanism underlying the calcium antagonist withdrawal syndrome.

What Is the Role of Assessing Ischemia to Optimize Therapy and Outcomes for Patients with Stable Angina and Non-obstructed Coronary Arteries?

Ischemic heart disease (IHD) is a leading global cause of ill-health and premature death. Clinical research into IHD is providing new insights into the pathophysiology, epidemiology and treatment of this condition. The major endotypes of IHD include coronary heart disease (CHD) and vasomotor disorders, including microvascular angina and vasospastic angina. Considering unselected patients presenting with stable chest pain, the pre-test probability of CHD is higher in men whereas the pre-test probability of a vasomotor disorder is higher in women. The diagnostic accuracy of diagnostic tests designed to assess coronary anatomy and disease and/or coronary vascular function (functional tests) differ for coronary endotypes. Clinical management should therefore be personalized and take account of sex-related factors. In this review, we consider the definitions of angina and myocardial ischemia. We then appraise the mechanistic links between myocardial ischemia and anginal symptoms and the relative merits of non-invasive and invasive diagnostic tests and related clinical management. Finally, we describe the rationale and importance of stratified medicine of IHD.

Feasibility of right coronary artery first ergonovine provocation test

BACKGROUND

Intracoronary (IC) provocation angiography is recommended when variant angina is suspected. However, specific procedure-related factors remain uncertain.

METHODS

Intracoronary ergonovine infusion was used for the provocation test. About 10, 20, and 40 μg of ergonovine were sequentially injected into the right coronary artery (RCA). During a negative or intermediate response or depending on the clinician's discretion, the left coronary artery (LCA) was injected with incremental doses of 20, 40, and 80 μg of ergonovine or vice versa. If significant coronary spasm or positive clinical findings were noted, the test was stopped immediately and IC nitroglycerine was injected.

RESULTS

We reviewed a total of 725 patients (male: 402; mean age: 58.5 years). Spasm-positive response was observed in 269 patients (37.1%), intermediate response in 113 patients (15.6%), and negative response in 343 patients (47.3%). The right radial artery approach was used in most cases (92.6%), and the RCA first approach was mainly chosen (95.0%). The provocation results in the RCA and LCA (93.4%, 381/408) were highly consistent, and the clinically significant discrepancy rate (RCA positive/LCA negative or RCA negative/LCA positive) was 1.5% (6/408). The RCA-alone provocation test can identify spasm-positive response in 93.4% of the patients (228/244). The mean procedure time was 39.9 ± 11.0 min, and approximately 3.3% (24/725) of the patients developed acute complications.

CONCLUSIONS

The RCA-first IC ergonovine provocation test is feasible, and the RCA-alone spasm provocation could be acceptable except in an intermediate response, highly clinically suspected cases, or high-risk patients.

Bronchial Asthma and Rest Angina: Is It Safe to Perform Acetylcholine Spasm Provocation Tests in These Patients?

Objective Acetylcholine (ACh) use in patients with bronchial asthma (BA) is contraindicated. We examined the clinical usefulness and safety of ACh spasm provocation tests in rest angina patients with BA. Patients The study subjects were 495 rest angina patients (mean age: 64.4±10.9 years old, male: 81.0%). Organic stenosis was found in 69 patients (13.9%). Methods We investigated 495 rest angina patients who underwent ACh spasm provocation tests. ACh was injected in incremental doses of 20/50/100/200 μg into the left coronary artery and 20/50/80 μg into the right coronary artery. Provoked positive spasm was defined as transient ≥90% luminal narrowing and usual chest pain or ischemic electrocardiogram changes. Results Among 495 rest angina patients, 13 (2.6%) were complicated with BA. Eleven patients with BA were controlled under medications, and two patients had a history of medication for BA. The clinical characteristics were not markedly different between rest angina patients with and without BA. The rate of multi-vessel spasm was markedly higher in patients with BA than that in those without BA. No complications during ACh spasm provocation tests were recognized in rest angina patients with BA, whereas major complications in those without BA were observed in eight patients including two ventricular fibrillations, three non-sustained ventricular tachycardias, and three shocks. We were able to perform all 495 ACh spasm provocation tests without any irreversible complications, while electrical defibrillation was necessary for 2 patients without BA. Conclusion We were able to perform ACh spasm provocation tests in rest angina patients with BA irrespective of the off-label use of ACh.

Coronary provocative tests in the catheterization laboratory: Pathophysiological bases, methodological considerations and clinical implications

The paradigm for the management of patients presenting with angina and/or myocardial ischemia has been historically centered on the detection and treatment of obstructive coronary artery disease (CAD). However, in a considerable proportion (30-50%) of patients undergoing coronary angiography, obstructive CAD is excluded. Thus, functional mechanisms may be involved in determining myocardial ischemia and should be investigated. In particular, coronary vasomotor disorders both at epicardial and at microvascular level may play a crucial role, but a definitive diagnosis of these disorders can at times be difficult, given the transience of symptoms, and often requires the use of coronary provocative tests. Of importance, these tests may provide relevant information on the pathogenic mechanism of myocardial ischemia, allowing physicians to tailor the therapies of their patients. Furthermore, several studies underscored the important prognostic information deriving from the use of coronary provocative tests. Nevertheless, their use in clinical practice is currently limited and mainly restricted to specialized centers, with only a minority of patients receiving a benefit from this diagnostic approach. In this review, we explain the pathophysiological bases for the use of provocative tests, along with their clinical, prognostic and therapeutic implications.

A review of diagnosis, etiology, assessment, and management of patients with myocardial infarction in the absence of obstructive coronary artery disease

Myocardial infarction (MI) in the absence of obstructive coronary artery disease (MINOCA) is prevalent in around 5% of acute myocardial infarction (AMI) presentations. MINOCA is a heterogeneous entity with many different etiologies. It is important for health care providers to familiarize themselves with the disease process, presentation, and possible underlying causes in order to guide appropriate management strategies. In this article, the authors review the contemporary definition, etiologies and assessment, and management for AMI patients with MINOCA.

Idiopathic Ventricular Fibrillation: Role of Purkinje System and Microstructural Myocardial Abnormalities

Idiopathic ventricular fibrillation is diagnosed in patients who survived a ventricular fibrillation episode without any identifiable structural or electrical cause after extensive investigations. It is a common cause of sudden death in young adults. The study reviews the diagnostic value of systematic investigations and the new insights provided by detailed electrophysiological mapping. Recent studies have shown the high incidence of microstructural cardiomyopathic areas, which act as the substrate of ventricular fibrillation re-entries. These subclinical alterations require high-density endo- and epicardial mapping to be identified using electrogram criteria. Small areas are involved and located individually in various sites (mostly epicardial). Their characteristics suggest a variety of genetic or acquired pathological processes affecting cellular connectivity or tissue structure, such as cardiomyopathies, myocarditis, or fatty infiltration. Purkinje abnormalities manifesting as triggering ectopy or providing a substrate for re-entry represent a second important cause. The documentation of ephemeral Purkinje ectopy requires continuous electrocardiography monitoring for diagnosis. A variety of diseases affecting Purkinje cell function or conduction are potentially at play in their pathogenesis. Comprehensive investigations can therefore allow the great majority of idiopathic ventricular fibrillation to ultimately receive diagnoses of a cardiac disease, likely underlain by a mosaic of pathologies. Precise phenotypic characterization has significant implications for interpretation of genetic variants, the risk assessment, and individual therapy. Future improvements in imaging or electrophysiological methods may hopefully allow the identification of the subjects at risk and the development of primary prevention strategies.

Spasm Provocation Tests under Medication May Help Decide on Medical or Mechanical Therapy in Patients with Aborted Sudden Cardiac Death due to Coronary Spasm

Objective The decision to perform medical or mechanical therapy in patients with aborted sudden cardiac death (ASCD) due to coronary spasm is controversial. The Japanese Circulation Society guidelines for the diagnosis and treatment of patients with coronary spastic angina mentioned that implantable cardioverter-defibrillator (ICD) is one option in patients with ASCD due to coronary spasm. We investigated the usefulness of spasm provocation tests under medications in five patients with ASCD due to coronary spasm. Methods We performed the spasm provocation tests under medications in five ASCD patients due to coronary spasm. Pharmacological spasm provocation tests, including five acetylcholine (ACh) tests, two ergonovine (ER) tests, and two ACh added after ER tests, were performed to estimate the effect of medications to suppressing the next fatal spasms. Results ACh tests under medications did not provoke spasm in one patient but did provoke in two patients. In the remaining two patients, neither the ACh test nor the ER test provoked spasm, but the ACh added after ER test induced a focal spasm in one coronary artery. We increased the medication dosage in four patients. An ICD was implanted in two patients, including one with refractory spasm and one with left main trunk spasm. One patient died due to pulseless electrical activity without ventricular fibrillation, while the remaining four patients survived. Conclusion Spasm provocation tests under medication in patients with ASCD due to coronary spasm may be an option when deciding on medical or mechanical therapy.

Acute Coronary Syndrome with Non-ruptured Plaques (NONRUPLA): Novel Ideas and Perspectives

PURPOSE OF REVIEW

In this review article, we focus on the mechanisms and features of acute coronary syndromes (ACS) with no ruptured plaque (NONRUPLA) highlighting the uncertainties over diagnostic evaluation and treatment.

RECENT FINDINGS

The most common cause of ACS is obstruction due to atherosclerotic plaque ruptured or erosion. In 14% of patients who present in the Emergency Department as myocardial infarction, the final diagnosis is ACS with NONRUPLA. Although the clinical presentation of NONRUPLA may mimic myocardial infarction, the underlying pathogenesis is different, and it may guide therapeutic approaches and overall prognosis that vary according to etiology. The possible mechanisms of ACS with NONRUPLA are coronary embolism, acute dissection of the aorta or coronary artery, vasospasm, microvascular dysfunction, the imbalance between oxygen demand and supply, coronary trauma and stent complications, direct cellular toxicity and damage, Takotsubo syndrome, and myocardial infarction with non-obstructive coronary arteries (MINOCA).

Diagnostic and Prognostic Value of Ergonovine Echocardiography for Noninvasive Diagnosis of Coronary Vasospasm

OBJECTIVES

This study sought to obtain large-scale evidence supporting the clinical usefulness of ergonovine echocardiography.

BACKGROUND

The role of noninvasive ergonovine provocation testing with echocardiographic monitoring of ventricular wall motion (ergonovine echocardiography) needs to be defined.

METHODS

Clinical data of patients who underwent ergonovine echocardiography in 3 tertiary referral hospitals in South Korea were analyzed.

RESULTS

Ergonovine echocardiography was performed in 14,012 patients (mean age 52.8 ± 11.1 years; 6,213 [44.3%] women) after exclusion of significant coronary arterial stenosis by functional (treadmill or perfusion scan, n = 9,824) or anatomic test (invasive or computerized tomographic coronary angiography, n = 4,188). Premature termination developed in 0.4% (n = 51), and a positive result was observed in 2,144 patients (15.3%), with variable frequencies according to the diagnosis (acute coronary syndrome [38.2%], variant angina [31.8%], effort angina [14.9%], aborted sudden cardiac death [17.6%], syncope [9.9%]). There was no mortality or development of myocardial infarction during the test. During median follow-up of 11.4 (interquartile range: 7.2 to 15.8) years, death of any cause and cardiovascular death occurred in 494 and 143 patients, respectively. The 10-year overall (96.7 ± 0.2% vs. 91.5 ± 0.6%; p < 0.0001) and cardiovascular mortality-free (99.2 ± 0.1% vs. 96.7 ± 0.4%; p < 0.0001) survival rates were lower in patients with positive ergonovine echocardiography. Regarding patients with positive test results, the functional test group and the anatomic test group did not show a significant difference in the survival rates. After adjustment of age and male sex, a positive test was an independent risk factor associated with all-cause mortality (hazard ratio: 1.879, 95% confidence interval: 1.548 to 2.280; p < 0.001) and cardiovascular death (hazard ratio: 2.903, 95% confidence interval: 2.061 to 4.089; p < 0.001).

CONCLUSIONS

Ergonovine echocardiography for coronary vasospasm diagnosis could be safely performed even without angiographic documentation of fixed coronary stenosis depending on the clinical presentation, and provided important prognostic implication. Ergonovine echocardiography can replace the invasive spasm provocation testing, which has been overlooked unfairly.

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.

Pharmacological spasm provocation testing in 2500 patients: provoked spasm incidence, complications and cardiac events

Pharmacological spasm provocation tests such as acetylcholine (ACh) and ergonovine (ER) had been performed in the clinic. We retrospectively analyzed the incidence of provoked spasm, complications during testing and the cardiac events after these tests. From January 1991 and October 2018, we performed pharmacological spasm provocation tests in 2500 patients: 1810 ACh tests, 1232 ER tests, 542 both tests, and 310 ACh added after ER tests. ACh was injected in incremental doses of 20/50/100/200 μg into the LCA and 20/50/80 μg into the RCA. ER was administered as a total dose of 64 μg into the LCA and 40 μg into the RCA. When adding ACh after ER, the total dose was 50/80 μg into the RCA and 100/200 μg into the LCA. Positive spasm was defined as ≥ 90% stenosis and usual chest pain or ischemic ECG changes. Mean follow-up duration was 47.5 ± 29.9 months. Overall, provoked positive spasm was found in 1095 patients (43.8%). The incidence of positive provoked spasm during ACh testing was significantly higher than that during other tests (ACh: 48.7% vs. ER: 28.9%, Both: 24%, ACh added after ER: 33.5%, p < 0.001). Multiple spasms were remarkably more frequent during ACh testing compared with the other 3 types of testing (ACh: 28.2% vs. ER: 7.4%, Both: 4.1%, ACh added after ER: 13.2%, p < 0.001). No death or acute myocardial infarction was observed, while major complications during ACh testing were significantly more frequent than during ER testing. Readmission due to recurrent angina pectoris in spasm-positive patients was remarkably more frequent than in spasm-negative patients. The incidence of sudden cardiac death, ventricular fibrillation, and acute coronary syndrome were not different between the spasm-positive and spasm-negative groups during the follow-up periods. We could perform all spasm provocation tests without any irreversible complications. All sequential spasm provocation tests were useful for documenting coronary spasm.

Diagnosis of coronary microvascular dysfunction in the clinic

The coronary microcirculation plays a pivotal role in the regulation of coronary blood flow and cardiac metabolism. It can adapt to acute and chronic pathologic conditions such as coronary thrombosis or long-standing hypertension. Due to the fact that the coronary microcirculation cannot be visualized in human beings in vivo, its assessment remains challenging. Thus, the clinical importance of the coronary microcirculation is still often underestimated or even neglected. Depending on the clinical condition of the respective patient, several non-invasive (e.g. transthoracic Doppler-echocardiography assessing coronary flow velocity reserve, cardiac magnetic resonance imaging, positron emission tomography) and invasive methods (e.g. assessment of coronary flow reserve (CFR) and microvascular resistance (MVR) using adenosine, microvascular coronary spasm with acetylcholine) have been established for the assessment of coronary microvascular function. Individual patient characteristics, but certainly also local availability, methodical expertise and costs will influence which methods are being used for the diagnostic work-up (non-invasive and/or invasive assessment) in a patient with recurrent symptoms and suspected coronary microvascular dysfunction. Recently, the combined invasive assessment of coronary vasoconstrictor as well as vasodilator abnormalities has been titled interventional diagnostic procedure (IDP). It involves intracoronary acetylcholine testing for the detection of coronary spasm as well as CFR and MVR assessment in response to adenosine using a dedicated wire. Currently, the IDP represents the most comprehensive coronary vasomotor assessment. Studies using the IDP to better characterize the endotypes observed will hopefully facilitate development of tailored and effective treatments.

Role of endothelial dysfunction in determining angina after percutaneous coronary intervention: Learning from pathophysiology to optimize treatment

Endothelial dysfunction (EnD) is a hallmark feature of coronary artery disease (CAD), representing the key early step of atherosclerotic plaque development and progression. Percutaneous coronary intervention (PCI) is performed daily worldwide to treat symptomatic CAD, however a consistent proportion of patients remain symptomatic for angina despite otherwise successful revascularization. EnD plays a central role in the mechanisms of post-PCI angina, as it is strictly associated with both structural and functional abnormalities in the coronary arteries that may persist, or even accentuate, following PCI. The assessment of endothelial function in patients undergoing PCI might help to identify those patients at higher risk of future cardiovascular events and recurrent/persistent angina who might therefore benefit more from an intensive treatment. In this review, we address the role of EnD in determining angina after PCI, discussing its pathophysiological mechanisms, diagnostic approaches and therapeutic perspectives.

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.

[Vasospastic angina: An under-diagnosed pathology]

The clinical and physiopathological clinical entity known as spastic angina or variant angina has been long documented. It remains, however, an under-estimated condition, which is insufficiently diagnosed and explored. This pathology is associated with severe complications such as heart rhythm disorders, which may potentially result in ventricular fibrillation and cause sudden death. In Japan, this condition occurs more frequently and is better documented. Stimulation tests are also carried out more often and have a higher positivity rate than in France where vasospastic angina is less frequently reported and where provocation tests are associated with negative results and are, consequently, performed less often. In order to improve the detection of this pathology, its potential presence should be explored in patients with rest angina who experience chest pain in the second half of the night and also in instances of acute coronary syndrome with sudden death and no angiographically visible coronary artery disease. The diagnosis should be confirmed by means of ergonovine provocation tests. In order to enhance the sensitivity of these tests without increasing the risk of complications, injection of ergonovine should be preferably carried out via the intracoronary route. By increasing the frequency and sensitivity of these tests, this pathology, which responds well to medical treatment in many cases, could be amenable to therapeutic management as any other form of coronary artery disease.

Impact of serum lipoprotein(a) on endothelium-dependent coronary vasomotor response assessed by intracoronary acetylcholine provocation

BACKGROUND

Lipoprotein(a) [Lp(a)] is an independent risk factor for atherosclerotic vascular disease. However, there are limited data regarding the impact of Lp(a) levels on the incidence and severity of endothelium-dependent coronary vasomotor response.

PATIENTS AND METHODS

A total of 2416 patients without significant coronary artery lesion (<50% stenosis) by coronary angiography and underwent acetylcholine (ACh) provocation test were enrolled and categorized according to their serum Lp(a) level into four quartile groups: less than 6.70, 6.70-13.30, 13.30-26.27, and more than 26.27 mg/dl. The aim of this study is to estimate the incidence and severity of endothelium-dependent positive ACh provocation test in each group; moreover, to access the incidence of major adverse cardiovascular events, the composite of total death, myocardial infarction, and de novo percutaneous coronary intervention were compared between the four groups up to 5 years.

RESULTS

The group with higher Lp(a) had a higher incidence of coronary heart disease, myocardial infarction, and peripheral arterial disease history. However, there was no difference among the four groups as regards the incidence of positive ACh provocation test, spasm severity, spasm extent, and location. However, at up to 5 years of clinical follow-up, the higher-Lp(a) group showed higher total death, de novo percutaneous coronary intervention, recurrent angina, and total major adverse cardiovascular events compared with the lower-Lp(a) groups.

CONCLUSION

In our study, there was no relationship between the elevated Lp(a) level and the vasospastic response to the intracoronary ACh provocation test; however, higher Lp(a) levels were associated with poor clinical outcomes up to 5 years.

Temporal Trends and Outcomes of Hospitalizations With Prinzmetal Angina: Perspectives From a National Database

BACKGROUND

Contemporary data regarding the temporal changes in prevalence and outcomes of hospitalizations with Prinzmetal angina are limited.

METHODS

We queried the National Inpatient Sample Database for the years 2002-2015 to identify hospitalizations with Prinzmetal angina. We described the temporal trends and outcomes in patients with Prinzmetal angina.

RESULTS

A total of 97,280 hospitalizations with Prinzmetal angina were identified. There was a significant increase in the number of hospitalizations with Prinzmetal angina (3678 in 2002 vs 8633 in 2015, P_trend <.001) as well as the proportion of hospitalizations with Prinzmetal angina among those with chest pain (P_trend <.001). There was an increase in the rates of in-hospital mortality (0.24% in 2002 vs 0.85% in 2015, P_trend = .02), which corresponded to a progressive increase in the burden of comorbidities among patients with Prinzmetal angina. Age >65 years, history of heart failure, chronic kidney disease, chronic liver disease, and acute myocardial infarction upon presentation were independent predictors of in-hospital mortality. Compared with patients with acute myocardial infarction without Prinzmetal angina, those with Prinzmetal angina presenting with acute myocardial infarction had a lower incidence of in-hospital mortality (odds ratio 0.24, 95% confidence interval 0.14-0.41).

CONCLUSIONS

In this large national analysis, there has been an increase in the prevalence of hospitalizations with Prinzmetal angina. Older age, heart failure, chronic kidney disease, chronic liver disease, and acute myocardial infarction were predictors of higher mortality among patients with Prinzmetal angina. Patients with Prinzmetal angina who developed acute myocardial infarction had more favorable outcomes compared with myocardial infarction without Prinzmetal angina.

ST elevation in recovery post exercise with normal coronary arteries

We present the case of a 45-year-old healthy man who successfully completed three stages of the Bruce protocol but developed inferolateral ST segment elevation in the recovery phase. The ECG change was associated with a marked drop in blood pressure. He underwent emergency coronary angiography which revealed normal coronary arteries. It is likely that post-exercise hypotension triggered coronary spasm which caused the ST segment elevation. Alternatively, coronary spasm may have been the primary event, inducing sufficient myocardial ischaemia to cause a marked drop in blood pressure. Exercise tolerance testing is often a reliable test to rule out reversible myocardial ischaemia. While the physician is focused on ischaemic changes or rhythm abnormalities developing during the exercise phase, the recovery period is just as important and requires as much vigilance. Coronary vasospasm can result in significant ST changes and haemodynamic compromise at any point during the test, and the ECG traces can be indistinguishable from a classic ST elevation myocardial infarction, as in the present case.

Heart rate recovery and blood pressure response during exercise testing in patients with microvascular angina

Background

Angina pectoris with a normal coronary angiogram, termed microvascular angina (MVA), is an important clinical entity; however, its causes remain unclear. Autonomic dysfunction is one of the possible causes. Therefore, this study aimed to investigate parasympathetic dysfunction assessed by heart rate recovery (HRR) and increased sympathetic activity assessed by exaggerated blood pressure (BP) response (EBPR) to exercise in MVA.

Methods

The study participants were consecutive patients with anginal chest pain who underwent both coronary angiography with an ergonovine provocation test and a treadmill exercise test between January 2008 and February 2015. Patients with significant coronary artery disease (coronary artery stenosis ≥50%) or significant coronary artery spasm (≥90%) were excluded. Based on the treadmill exercise test, patients were categorized into the microvascular angina (MVA) group (patients with uniform ST depression ≥1 mm) and the control group. HRR was defined as peak heart rate minus heart rate after a 1 min recovery; blunted HRR was defined as ≤12 beats/min. EBPR was defined as a peak exercise systolic BP ≥210 mmHg in men and ≥ 190 mmHg in women. These parameters were compared between patients with MVA and the controls.

Results

Among the 970 enrolled patients (mean age 53.1 years; female 59.0%), 191 (20.0%) were diagnosed with MVA. In baseline characteristics, the MVA group had older participants, female predominance, and a higher prevalence of hypertension. The MVA group showed significantly lower HRR 1 min (24.9 ± 15.9 vs. 31.3 ± 22.7, p <  0.001) compared with the control group. Moreover, the proportion of EBPR was significantly higher in the MVA group than in the control group (21.5% vs. 11.6%, p <  0.001). Multivariable logistic regression analysis showed that age (odds ratio (OR), 1.045; 95% confidence interval (CI), 1.026-1.064; p <  0.001), HRR 1 min (OR, 0.990; 95% CI, 0.982-0.999; p = 0.022), and EBPR (OR, 1.657; 95% CI, 1.074-2.554; p = 0.022) were independently associated with MVA.

Conclusion

HRR and EBPR were associated with MVA, which suggests a link between MVA and autonomic dysregulation.

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.

Differential incidence and morphology of provoked spasm between intracoronary acetylcholine and ergonovine testing: recommendation of supplementary use

When cardiologists diagnose patients with coronary spastic angina, Japanese Circulation Society (JCS) guidelines recommend the intracoronary injection of acetylcholine (ACh) and ergonovine (ER) as class I. However, the pharmacological difference between ACh and ER is controversial in the clinic. We performed both ACh and ER tests in the same 528 patients during 26 years. We investigated the provoked spasm configuration, spasm site, and clinical characteristics of provoked spasm between ACh and ER, retrospectively. We defined positive spasm as ≥90% luminal narrowing. Provoked positive spasm was observed in 161 right coronary arteries (RCA) including 83 ACh just positive, 35 ER just positive, and 43 both positive. In contrast, positive spasm was documented in 172 left coronary arteries (LCA) including 94 ACh just positive, 28 ER just positive, and 50 both positive. ACh provoked spasm more distally and diffusely, while ER induced spasm more proximally and totally or focally in the RCA. In the LCA, ACh provoked spasm more proximally, whereas ER induced spasm more distally. ER testing after the negative ACh tests of RCA and LCA documented new positive spasms in 10.3% (35/340) and 7.4% (28/376), respectively. Coronary artery trees may each have a sensitive receptor on each segment. We recommend the supplementary use of ACh and ER to document coronary artery spasm in the cardiac catheterization laboratory.

The multi-vessel and diffuse coronary spasm is a risk factor for persistent angina in patients received anti-angina medication

Coronary artery spasm (CAS) is known to be a risk factor for cardiovascular events. However, there is limited data whether the multi-vessel and diffuse spasm (MVDS) is related to more adverse clinical outcomes compared to the Non-MVDS. The aim of this study is to evaluate the impact of the MVDS on clinical outcomes during a 3-year clinical follow-up period.A total 2797 patients underwent coronary angiography (CAG) with acetylcholine (ACH) provocation test from Nov 2004 to Oct 2010 were enrolled. It is a single-center, observational, prospective, all-comers registry designed to reflect the "real world" practic. The patients were divided into the 3 groups; the negative spasm (NS) group (n = 1188), the Non-MVDS group (n = 1081), and the MVDS group (n = 528). The incidence of major adverse cardiac events (MACE) and recurrent angina was evaluated up to 3 years. To minimize confounding factors, multivariable Cox-proportional hazards regression analysis was performed.In the 3-year clinical follow-up, the incidence of total death, myocardial infarction, de novo percutaneous coronary intervention (PCI), cerebrovascular accident and MACE were similar among the 3 groups. However, recurrent angina occurred more frequently in the MVDS group than in the NS group (hazard ratio [HR], 1.96; 95% confidence interval [CI], 1.27-3.02; P = .002). Recurrence angina between the MVDS group and the Non-MVDS group was not statistically significant (HR, 1.36; 95% CI, 0.91-2.03; P = .129).In this study, although the incidence of major adverse cardiovascular events were not different regardless of spasm type, the MVDS was associated with higher incidence of recurrent chest pain requiring repeat CAG during the 3-year follow-up period, suggesting more intensive optimal medical therapy with close clinical follow up would be necessary for this particular subset of patients.

[Coronary spasm a diagnostic and therapeutic challenge]

Vasospastic angina is a clinical and physio-pathological entity, which has been documented for many years, but its diagnosis is under-estimated despite the fact that though inadequately considered and investigated. This condition is potentially serious and can sometimes trigger severe arrhythmia resulting in ventricular fibrillation and sudden death. This pathology has a higher incidence in Asia, where it is, therefore, better documented with provocative testing being carried out more frequently, while in France, these tests are not sufficiently performed probably due to the fact that they often produce negative findings. Provocative tests with Ergonovine injection should be performed via intra-coronary to improve its sensibility. Should this test become more sensitive and more routinely performed, this condition, which often responds well to medical treatment, could regain appropriate recognition as a coronary disease.

Effect of intracoronary adenosine on ergonovine-induced vasoconstricted coronary arteries

BACKGROUND

This study aimed to evaluate the effect of adenosine on epicardial coronary artery diameter during ergonovine provocation testing.

METHODS

A total of 158 patients who underwent an ergonovine provocation test with intracoronary adenosine injection between 2011 and 2014 were selected. Patients were divided into four groups based on the severity of percent diameter stenosis following intracoronary ergonovine administration: Group 1, induced spasm < 50%; Group 2, 50-89%; Group 3, 90-99%; and Group 4, total occlusion.

RESULTS

Spasm positivity was observed in 44 (27.8%) cases in the study population (mean age, 57.4 ± ± 10.7 years). Intracoronary adenosine increased the diameter of the ergonovine-induced epicardial artery by 0.51 ± 0.31 mm, 0.73 ± 0.39 mm, 0.44 ± 0.59 mm, and 0.01 ± 0.04 mm in Groups 1, 2, 3, and 4, respectively. Subsequent administration of nitroglycerin further increased vessel diameter by 0.49 ± 0.28 mm, 0.93 ± 0.68 mm, 2.11 ± 1.25 mm, and 2.23 ± 0.69 mm in Groups 1, 2, 3, and 4, respectively. The ratios of adenosine-induced diameter to reference diameter were significantly lower in patients with spasm positive results (0.68 [0.59-0.76] vs. 0.18 [0.00-0.41], p < 0.001 in the study population; 0.60 [0.54-0.67] vs. 0.40 [0.27-0.44], p < 0.001 in Group 2) with the best cut-off value of 0.505 (sensitivity 0.955, specificity 0.921).

CONCLUSIONS

Intracoronary administration of adenosine dilated the ergonovine-induced vasoconstricted epicardial coronary artery. The ratio of adenosine-induced diameter to reference diameter was significantly lower in patients with spasm positive results.

Coronary vasospasm-induced polymorphic ventricular tachycardia: a case report and literature review

Introduction

Coronary vasospasm is an uncommon but important cause of myocardial ischaemia and ventricular arrhythmias.

Case presentation

In this report, we present a striking example of vasospasm manifesting as ST-segment elevation and ventricular tachycardia on Holter monitoring. Later, spasm occurred during a procainamide challenge performed for suspected Brugada syndrome. The patient underwent implantable cardioverter-defibrillator insertion and was successfully treated with oral calcium channel blocker.

Discussion

We review contemporary data regarding management and outcomes in coronary vasospasm and discuss the use of implantable defibrillator therapy in patients who have sustained a significant arrhythmic event.