Frequency of provoked coronary vasospasm in patients undergoing coronary arteriography with spasm provocation test of acetylcholine

Prevalence of Coronary Vasomotor Disorders in Patients With Angina and Nonobstructive Coronary Arteries: A Sydney Experience

BACKGROUND

Patients with angina and non-obstructive coronary arteries (ANOCA) frequently have coronary vasomotor disorders (CVaD), characterised by transient pathological vasoconstriction and/or impaired microvascular vasodilatation. Functional coronary angiography is the gold standard for diagnosing CVaD. Despite recommendations, testing is only available at a limited number of Australian and New Zealand centres. This study aimed to determine the prevalence of CVaDs in an Australian ANOCA population and identify predictive factors associated with specific endotypes.

METHOD

Functional coronary angiography was performed in patients with suspected ANOCA. Vasoreactivity testing was performed using intracoronary acetylcholine provocation. A pressure-temperature sensor guidewire was used for coronary physiology assessment. Comprehensive clinical data on patient characteristics, cardiac risk factors, and symptom profiles was collected before testing.

RESULTS

This prospective observational study at Royal Prince Alfred and Concord Repatriation General Hospital included 110 patients (58±13 years with 63.6% women), with 81.8% (90/110) having a CVaD. Regarding specific ANOCA endotypes, microvascular angina (MVA) occurred in 31.8% (35/110) of cases, vasospastic angina (VSA) in 25.5% (28/110) and a mixed presentation of MVA and VSA in 24.5% (27/110) of patients. Patients with CVaD were found to be older (59±11 vs 51±15, p=0.024), overweight (61.1% vs 15.0%, p<0.001) and had a worse quality of life (EuroQol 5 Dimensions-5 Levels; 0.61 vs 0.67, p=0.043). MVA was associated with being overweight (odds ratio [OR] 4.2 [95% confidence interval [CI] 1.9-9.3]; p=0.015) and ischaemia on stress testing (OR 2.4 [95% CI 1.1-4.3]; p=0.028), while VSA was associated with smoking (OR 9.1 [95% CI 2.21-39.3]; p=0.007).

CONCLUSIONS

Coronary vasomotor disorders are highly prevalent among ANOCA patients. This study highlights the importance of increasing national awareness and the use of functional coronary angiography to evaluate and manage this unique cohort.

RNF213 Variants, Vasospastic Angina, and Risk of Fatal Myocardial Infarction

Importance

Vasospastic angina (VSA) is vasospasm of the coronary artery and is particularly prevalent in East Asian populations. However, the specific genetic architecture for VSA at genome-wide levels is not fully understood.

Objective

To identify genetic factors associated with VSA.

Design, Setting, and Participants

This was a case-control genome-wide association study of VSA. Data from Biobank Japan (BBJ; enrolled patients from 2002-2008 and 2013-2018) were used, and controls without coronary artery disease (CAD) were enrolled. Patients from the BBJ were genotyped using arrays or a set of arrays. Patients recruited between 2002 and 2005 were classified within the first dataset, and those recruited between 2006 and 2008 were classified within the second dataset. To replicate the genome-wide association study in the first and second datasets, VSA cases and control samples from the latest patients in the BBJ recruited between 2013 and 2018 were analyzed in a third dataset.

Exposures

Single-nucleotide variants associated with VSA.

Main Outcomes and Measures

Cases with VSA and controls without CAD.

Results

A total of 5720 cases (mean [SD] age, 67 [10] years; 3672 male [64.2%]) and 153 864 controls (mean [SD] age, 62 [15] years; 77 362 male [50.3%]) in 3 datasets were included in this study. The variants at the RNF213 locus showed the strongest association with VSA across the 3 datasets (odds ratio [OR], 2.34; 95% CI, 1.99-2.74; P = 4.4 × 10-25). Additionally, rs112735431, an Asian-specific rare deleterious variant (p.Arg4810Lys) experimentally shown to be associated with reduced angiogenesis and a well-known causal risk for Moyamoya disease was the most promising candidate for a causal variant explaining the association. The effect size of rs112735431 on VSA was distinct from that of other CADs. Furthermore, homozygous carriers of rs112735431 showed an association with VSA characterized by a large effect estimate (OR, 18.34; 95% CI, 5.15-65.22; P = 7.0 × 10-6), deviating from the additive model (OR, 4.35; 95% CI, 1.18-16.05; P = .03). Stratified analyses revealed that rs112735431 exhibited a stronger association in males (χ21 = 7.24; P = .007) and a younger age group (OR, 3.06; 95% CI, 2.24-4.19), corresponding to the epidemiologic features of VSA. In the registry, carriers without CAD of the risk allele rs112735431 had a strikingly high mortality rate due to acute myocardial infarction during the follow-up period (hazard ratio, 2.71; 95% CI, 1.57-4.65; P = 3.3 × 10-4). As previously reported, a possible overlap between VSA and Moyamoya disease was not found.

Conclusions and Relevance

Results of this study suggest that vascular cell dysfunction mediated by variants in the RNF213 locus may promote coronary vasospasm, and the presence of the risk allele could serve as a predictive factor for the prognosis.

Importance of provoked spasms at the sites of nonobstructive stenosis as well as at the sites of obstructive stenosis in patients with obstructive coronary arteries and coronary spasm

OBJECTIVES

There are few reports regarding the prognosis in patients with obstructive coronary artery disease (OCAD) and vasospastic angina (VSA). This study investigated the clinical characteristics and clinical outcomes in patients with VSA and OCAD, especially regarding provoked spasm phenotypes and sites.

METHODS

This was a retrospective, observational, single-center study of 403 patients with typical or atypical angina-like chest pain undergoing acetylcholine (ACH) spasm provocation testing and OCAD. An obstructed coronary artery was defined as ≥50% luminal narrowing. We defined positive epicardial spasm as ≥90% transient stenosis and usual chest symptoms or ischemic ECG changes.

RESULTS

Among these 403 patients with OCAD, positive spasm by intracoronary ACH testing was observed in 196 patients (49%), whereas negative spasm was found in the remaining 207 patients (51%). The clinical outcomes in the patients with OCAD and provoked spasm were not different according to the provoked-spasm phenotypes. Furthermore, the clinical outcomes were unsatisfactory in the patients with spasm at the site of nonobstructive lesion alone compared with those with spasm at the site of obstructive and nonobstructive lesions.

CONCLUSION

We should precisely diagnose patients with OCAD who have provoked spasm by using intracoronary ACH testing and medicate the nonobstructive vessels in patients with OCAD and VSA under optimal coronary vasodilators.

Coronary spasm and vasomotor dysfunction as a cause of MINOCA

Increasing evidence has shown that coronary spasm and vasomotor dysfunction may be the underlying cause in more than half of myocardial infarctions with non-obstructive coronary arteries (MINOCA) as well as an important cause of chronic chest pain in the outpatient setting. We review the contemporary understanding of coronary spasm and related vasomotor dysfunction of the coronary arteries, the pathophysiology and prognosis, and current and emerging approaches to diagnosis and evidence-based treatment.

Relationship between Inflammation and Vasospastic Angina

Coronary artery spasm (CAS) is a dynamic coronary stenosis causing vasospastic angina (VSA). However, VSA is a potentially lethal medical condition with multiple presentations, including sudden cardiac death. Despite investigations to explore its pathogenesis, no single mechanism has been found to explain the entire process of VSA occurrence. The roles of elevated local and systemic inflammation have been increasingly recognized in VSA. Treatment strategies to decrease local and systemic inflammation deserve further investigation.

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.

Angina and Arrhythmia Symptoms Following Multiple Bee Stings: Kounis Syndrome

Kounis syndrome (KS) is an acute coronary syndrome including coronary spasm, acute myocardial infarction, and stent thrombosis preceded by an anaphylactic, anaphylactoid, allergic, or hypersensitivity injury. In this case presentation, we discussed Type I and Type II KS. Case 1 was a 72-y-old man who presented to the emergency department with allergic symptoms and chest pain that developed after multiple bee stings. Electrocardiography showed ST depression in the lateral leads. Case 2 was a 42-y-old woman who presented to the emergency department with complaints of chest pain, dizziness, and presyncope that developed after multiple bee stings. Mobitz Type II Block with right bundle branch block was observed in 42 beats·min-1 in the electrocardiography. Both patients were first treated for allergic reaction. Although early percutaneous coronary intervention was performed for graft thrombosis in Case 1, a permanent pacemaker was inserted in Case 2. The patients were discharged without any complications. Increasing physician awareness towards the existence of KS can prevent fatal outcomes with early diagnosis and treatment.

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.

Perioperative coronary artery spasms in patients undergoing catheter ablation of atrial fibrillation

PURPOSE

Catheter ablation (CA) is an established treatment for atrial fibrillation (AF). Although coronary artery spasms (CAS) during or after ablation procedures have been described as a rare complication in some case reports, the incidence and characteristics of this complication have not been fully elucidated. The present observational study aimed to clarify the CAS in a large number of patients experiencing AF ablation.

METHODS

A total of 2913 consecutive patients (male: 78%, mean 66 ± 10 years) who underwent catheter ablation of AF were enrolled.

RESULTS

Nine patients (0.31%, mean 66 ± 10 years, 7 males) had transient ST-T elevation (STE). Eight out of the 9 patients had STE in the inferior leads. STE occurred after the transseptal puncture in 7 patients, after the sheath was pulled out of the left atrium in 1, and 2 h after the ablation procedure in 1. Six patients had definite angiographic CAS without any sign of an air embolization on the emergent coronary angiography. In the3 other patients, the STE improved either directly after an infusion of nitroglycerin or spontaneously before the CAG. The patients with CAS had a higher frequency of a smoking habit (89% vs. 53%; P = .04), smaller left atrial diameter (36 ± 6 vs. 40 ± 7; P = .07), and lower CHADS2 score (0.6 ± 0.5 vs. 1.3 ± 1.1; P = .004) than those without.

CONCLUSIONS

Although the incidence was rare (0.31%), CAS should be kept in mind as a potentially life-threatening complication throughout an AF ablation procedure especially performed under conscious sedation.

A Practical Approach to Invasive Testing in Ischemia with No Obstructive Coronary Arteries (INOCA)

Up to 65% of women and approximately 30% of men have ischemia with no obstructive coronary artery disease (CAD; commonly known as INOCA) on invasive coronary angiography performed for stable angina. INOCA can be due to coronary microvascular dysfunction or coronary vasospasm. Despite the absence of obstructive CAD, those with INOCA have an increased risk of all-cause mortality and adverse outcomes, including recurrent angina and cardiovascular events. These patients often undergo repeat testing, including cardiac catheterization, resulting in lifetime healthcare costs that rival those for obstructive CAD. Patients with INOCA often remain undiagnosed and untreated. This review discusses the symptoms and prognosis of INOCA, offers a systematic approach to the diagnostic evaluation of these patients, and summarizes therapeutic management, including tailored therapy according to underlying pathophysiological mechanisms.

Relation Between Coronary Tortuosity and Vasomotor Dysfunction in Patients Without Obstructed Coronaries?

Background: A large proportion of patients with angina and no obstructive coronary artery disease (ANOCA) has underlying coronary vasomotor dysfunction (CVDys), which can be diagnosed by a coronary function test (CFT). Coronary tortuosity is a common angiographic finding during the CFT. Yet, no data exist on the association between vasomotor dysfunction and coronary tortuosity.

Aim: To investigate the association between CVDys and coronary tortuosity in patients with ANOCA

Methods: All consecutive ANOCA patients who underwent clinically indicated CFT between February 2019 and November 2020 were included. CFT included acetylcholine spasm testing to diagnose epicardial or microvascular spasm, and adenosine testing to diagnose microvascular dysfunction (MVD). MVD was defined as an index of microvascular resistance (IMR) ≥ 25 and/or coronary flow reserve (CFR) <2.0. Coronary tortuosity, was scored (no, mild, moderate or severe) based on the angles of the curvatures in the left anterior descending (LAD) artery on angiography.

Results: In total, 228 patients were included (86% female, mean age 56 ± 9 years). We found coronary artery spasm in 81% of patients and MVD in 45% of patients (15%: abnormal CFR, 30%: abnormal IMR). There were 73 patients with no tortuosity, 114 with mild tortuosity, 41 with moderate tortuosity, and no patients with severe tortuosity. No differences were found in cardiovascular risk factors or medical history, and the prevalence of CVDys did not differ between the no tortuosity, mild tortuosity and moderate tortuosity group (82, 82, and 85%, respectively).

Conclusion: In this study, CVDys was not associated with coronary tortuosity. Future experimental and clinical studies on the complex interplay between coronary tortuosity, wall shear stress, endothelial dysfunction and coronary flow are warranted.

Drug-Induced Atrial Fibrillation / Atrial Flutter

Drug-induced atrial fibrillation / flutter (DIAF) is a serious and potentially life-threatening complication of pharmacotherapy. Purpose of the work: systematization and analysis of scientific literature data on drugs, the use of which can cause the development of DIAF, as well as on epidemiology, pathophysiological mechanisms, risk factors, clinical picture, diagnosis and differential diagnosis, treatment and prevention of DIAF. Analysis of the literature has shown that many groups of drugs can cause the development of DIAF, with a greater frequency while taking anticancer drugs, drugs for the treatment of the cardiovascular, bronchopulmonary and central nervous systems. The mechanisms and main risk factors for the development of DIAF have not been finally established and are known only for certain drugs, therefore, this section requires further study. The main symptoms of DIAF are due to the severity of tachycardia and their influence on the parameters of central hemodynamics. For diagnosis, it is necessary to conduct an electrocardiogram (ECG) and Holter monitoring of an ECG and echocardiography. Differential diagnosis should be made with AF, which may be caused by other causes, as well as other rhythm and conduction disturbances. Successful treatment of DIAF is based on the principle of rapid recognition and immediate discontinuation of drugs (if possible), the use of which potentially caused the development of adverse drug reactions (ADR). The choice of management strategy: heart rate control or rhythm control, as well as the method of achievement (medication or non-medication), depends on the specific clinical situation. For the prevention of DIAF, it is necessary to instruct patients about possible symptoms and recommend self-monitoring of the pulse. It is important for practitioners to be wary of the risk of DIAF due to the variety of drugs that can potentially cause this ADR.

Intracoronary acetylcholine testing among 746 consecutive Japanese patients with angina-like chest pain and unobstructed coronary artery disease

Aims 

Intracoronary acetylcholine (ACh) testing is useful for the detection of epicardial spasm (ES) and coronary microvascular spasm (CMS). We retrospectively analysed the incidence of ES and CMS in consecutive Japanese patients with unobstructed coronary artery disease.

Methods and results

From January 1991 to February 2019, we performed intracoronary ACh testing of 1864 patients. Among these patients, a total of 746 consecutive patients (254 women, mean age 64 ± 11 years) who underwent first diagnostic angiography for suspected myocardial ischaemia and had unobstructed coronary arteries (<50%) were enrolled. Epicardial spasm was defined as ≥90% stenosis and usual chest symptoms and ischaemic ECG changes, while CMS was defined as <75% stenosis and usual chest symptoms and ischaemic ECG changes. We performed intracoronary ACh testing on both coronary arteries in 96% (716/746) of all subjects. Overall, ES was found in 329 patients (44%), whereas CMS was revealed in 40 patients (5%) including 4 patients with coexisting ES. In patients with ES, women made up 22%, and approximately three-quarters of the patients had resting chest pain. In contrast, women composed 65% (26/40) of those with CMS, and 15 patients with CMS had another chest symptom. Coronary microvascular spasm was frequently observed in the left coronary artery (LCA) but not the right coronary artery. Electrical cardioversion was necessary for two patients.

Conclusions 

Coronary microvascular spasm was recognized in only 5% of consecutive Japanese patients with unobstructed coronary artery disease, whereas ES was revealed in 44% of those patients. Coronary microvascular spasm was often observed in women and in the LCA.

Sex-related Differences in Patients with Positive Coronary Spasm as Identified by Acetylcholine Testing

Objective A pathological acetylcholine (ACh) test was observed at lower ACh doses in females compared with males in European populations. We retrospectively analyzed the sex-related differences in Japanese patients with provoked positive spasm by ACh spasm provocation testing. Methods We performed the ACh spasm provocation tests in 1,854 patients from Jan 1991 until Mar 2019. 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 spasm was defined as >90% stenosis and usual chest pain or ischemic ECG changes. We compared the clinical characteristics, angiographical findings during ACh testing, and clinical outcomes between female and male patients with and without provoked positive spasm. Results Positive provoked spasm was diagnosed in 917 patients including 737 (80.4%) males and 180 (19.6%) females. The incidence of provoked positive spasm in females was significantly lower than that in males (33.5% vs. 56.0%, p<0.001). Female patients with provoked positive spasm tended to be older, have less history of smoking, less provoked spasm in the left circumflex artery, or less focal type spasm than male patients with provoked positive spasm. The incidence of ST elevation during ACh testing in male patients was significantly higher than that in female patients, whereas the frequency of ST depression in females was remarkably higher than that in males. The mean maximum used ACh dose for provoked positive spasm on both coronary arteries in female patients was significantly higher than that in male patients. The observed major complications during ACh testing did not differ substantially between the sexes. In addition, the prognosis in females with provoked positive spasm was not different from males. Conclusion Provoked positive spasm by ACh test was obtained at lower mean maximum ACh doses in males compared with females in Japanese patients.

Coronary artery spasm-induced acute myocardial infarction in patients with myocardial infarction with non-obstructive coronary arteries

Coronary artery spasm-induced acute myocardial infarction (CASIAMI) is one of the etiologies of myocardial infarction with non-obstructive coronary arteries (MINOCA). We retrospectively analyzed the incidence and clinical characteristics of Japanese patients with CASIAMI and non-obstructive coronary arteries. We experienced 62 patients with MINOCA (10 thrombosis, 7 unknown causes, and 45 CASIAMI) among 991 patients with suspected AMI. Pharmacological spasm provocation testing was performed in 37 patients. CASIAMI without obstructive coronary arteries was found in 4.5% of patients with suspected AMI and was observed in 73% of patients with MINOCA. Patients with CASIAMI were frequently males and had relatively small AMIs. Spontaneous spasm was recognized in 8 patients. We could reproduce provoked spasm in 37 patients with MINOCA, including 23 patients with multiple spasm. No patients died during the follow-up period. The clinical outcomes in patients with CASIAMI under optimal coronary vasodilators were satisfactory.

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.

Coincidence between spontaneous and inducible coronary spasm: acetylcholine test is clinically valued for diagnosing coronary spasm

There is no report regarding the correlation between spontaneous documented coronary spasm and acetylcholine (ACh)-inducible spasm. We retrospectively analyzed the coincidence between angiographical spontaneous coronary spasm and ACh-inducible spasm in the same patients. We recruited 28 patients with 30 angiographical spontaneous coronary spasm in 6009 patients with diagnostic and follow-up coronary arteriography from Jan 1991 and Mar 2019 in the cardiac catheterization laboratory. We could perform intracoronary ACh testing in 19 patients with 20 vessels. ACh was injected in incremental dose of 20/50/100 μg into the left coronary artery and 20/50/80 μg into the right coronary artery. Positive spasm was defined as > 90% stenosis and ischemic ECG changes. Angiographical documented spontaneous coronary spasm was observed in 0.47% (28/6009) of patients with diagnostic and follow-up coronary angiography. Intracoronary administration of ACh reproduced 15 spontaneous coronary spasm and no provoked spasm was observed in the remaining 5 vessels due to the administration of nitroglycerine or under medications. Spasm-provoked sites by ACh tests and ACh-inducible spasm configurations were almost similar to spontaneous spasm. Coincidence of provoked spasm site (93.3% vs. 6.7%, p < 0.001) and spasm configuration (93.3% vs. 6.7%, p < 0.001) was markedly higher than discordance. Intracoronary ACh testing can reproduce spontaneous coronary artery spasm in 75% of vessels with almost similar sites and same morphological characteristics irrespective of the administration of nitroglycerine or vasodilators. ACh test is a reliable method to document coronary artery spasm in the clinic.

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.

Role of acetylcholine spasm provocation test as a pathophysiological assessment in nonobstructive coronary artery disease

Coronary angiography (CAG) sometimes shows nonobstructive coronary arteries in patients with suspected angina or acute coronary syndrome (ACS). The high prevalence of nonobstructive coronary artery disease (CAD) in those patients has recently been reported not only in Japan but also in Western countries, and is clinically attracting attention. Coronary spasm is considered to be one of the leading causes of both suspected stable angina and ACS with nonobstructive coronary arteries. Coronary spasm could also be associated with left ventricular dysfunction leading to heart failure, which could be improved following the administration of calcium channel blockers. Because we rarely capture spontaneous attacks of coronary spasm with electrocardiograms or Holter recordings, an invasive diagnostic modality, acetylcholine (ACh) provocation test, can be useful in detecting coronary spasm during CAG. Furthermore, we can use the ACh-provocation test to identify high-risk patients with coronary spasm complicated with organic coronary stenosis, and then treat with intensive care. Nonobstructive CAD includes not only epicardial coronary spasm but also microvascular spasm or dysfunction that can be associated with recurrent anginal attacks and poor quality of life. ACh-provocation test could also be helpful for the assessment of microvascular spasm or dysfunction. We hope that cardiologists will increasingly perform ACh-provocation test to assess the pathophysiology of nonobstructive CAD.

Assessment of coronary vasomotor responses to acetylcholine in German and Japanese patients with epicardial coronary spasm-more similarities than differences?

Coronary spasm is an established cause for angina pectoris. Ethnic differences have been suggested among Asian compared to Caucasian patients regarding prevalence, gender distribution, and angiographic patterns of coronary spasm. The aim of this study was to compare contemporary German and Japanese patients with coronary spasm. Between 2011 and 2015, 149 patients with resting angina and unobstructed coronary arteries with acetylcholine-induced epicardial spasm were enrolled in Stuttgart, Germany (n = 69) and Sendai, Japan (n = 80). All patients underwent intracoronary acetylcholine testing according to a standardized protocol. Comprehensive analysis included type of spasm (focal/diffuse), dose of acetylcholine leading to spasm, and frequency of multivessel spasm. Patients in this study were 61 ± 11 years old, predominantly female (54%), and had normal left ventricular ejection fraction (73 ± 9%). Diffuse spasm was the most prevalent type of spasm (85%) whereas focal spasm was found in the remaining 15% of patients. 31% of patients had multivessel spasm. Comparing the German with the Japanese patients, distribution of spasm type (focal/diffuse, p = 0.19) and frequency of multivessel spasm (p = 0.22) were comparable. Moreover, when Japanese patients were compared with German patients and diffuse spasm with focal spasm patients, respectively, no significant differences were observed regarding the acetylcholine dose required to induce spasm (p = 0.078 and p = 0.46, respectively). In conclusion, diffuse epicardial coronary spasm is the most frequent finding among German and Japanese patients with resting angina, unobstructed coronary arteries, and epicardial spasm on acetylcholine testing. Japanese and German patients share several similarities including comparable types of spasm and frequency of multivessel spasm.

General internists of experience suspected variant angina as gastroesophageal reflux diseases in two cases: Heart burn may be related to coronary spasm

General physicians of experience suspected variant angina as gastroesophageal reflux disease (GERD) due to heart burn in two patients. Proton pump inhibitors were administered in these patients, although spontaneous ST segment elevations were recognized and total or subtotal coronary spasm was provoked by the pharmacological spasm provocation tests. Under the vasodilators but not proton pump inhibitors, two patients complained of neither heart burn nor chest symptoms. General internists and cardiologists should bear in mind coronary spasm when they suspect GERD due to heart burn. Guidelines for GERD may note the necessity of differential diagnosis of coronary artery spasm as one of etiology of GERD-related chest symptoms. <Learning objective: We describe two cases of active variant angina suspected as gastroesophageal reflux disease (GERD) initially by experienced general internists. General physicians and cardiologists should discriminate GERD from coronary spastic angina or Prinzmetal variant angina.>.

Clinical usefulness of myocardial scintigraphy in patients with vasospastic angina

BACKGROUND

Myocardial scintigraphy is defined as class IIb in the Japanese Circulation Society guideline for diagnosis of vasospastic angina (VSA). However, Caucasian guidelines had no classification of cardiac scintigraphy for diagnosis of VSA.

OBJECTIVES

To clarify the clinical usefulness of myocardial scintigraphy, we analyzed the sensitivity and specificity of each cardiac scintigraphy.

METHODS

We extracted the 136 papers of myocardial scintigraphy from the PubMed database from 1980 to 2018 in patients with VSA. Finally we analyzed the 88 papers including 33 papers of^201-thallium (Tl), 10 papers of ¹²³I beta-methyl 15-para-iodophenyl 3(R, S)-methylpentadecanoic acid (BMIPP), 9 papers of ¹²³I-metaiodobenzylguanidine (MIBG), 4 papers of ^99mTc-sestamibi (MIBI: methoxy-isobutyl-isonitrile), and 2 papers of tetrofosmin to investigate the sensitivity and specificity of each tracer.

RESULTS

Tl, BMIPP, or MIBG cardiac scintigraphy were useful to diagnose patients with VSA, because sensitivity was 57-73%. Specificity was 55-83%. Sensitivity of left circumflex artery was significantly lower than other vessels. BMIPP imaging may be helpful for clinical course of VSA. However, myocardial scintigraphic abnormal findings may not always show the ischemic memory due to coronary artery spasm.

CONCLUSIONS

Recent cardiologists do not perform hyperventilation tests or MIBG scintigraphy for diagnosis of coronary spasm. After understanding the flow of the times, cardiologists should use Tl or BMIPP myocardial scintigraphy for VSA as one of supplementary tools in the real world.

Clinical characteristics in patients with rest angina and hypoplastic right coronary artery

Hypoplastic coronary artery disease is a rare congenital abnormality reported to be associated with myocardial infarction and sudden cardiac death. Provoked positive spasm in the left circumflex coronary artery (LCX) with pharmacological spasm provocation tests was remarkably lower than other coronary arteries. We sometimes encountered patients with rest angina and hypoplastic right coronary artery (H-RCA). Among 5953 patients with diagnostic and follow-up coronary arteriography, we found 93 patients (1.6%) with H-RCA. During the same period, we could perform spasm provocation tests in 564 patients with rest angina including 13 patients with H-RCA and 249 patients with effort angina including 10 patients with H-RCA. Pharmacological spasm provocation tests were performed in 51 of 93 patients including 34 patients with ischemic heart disease (IHD) and 17 patients with non-IHD. Provoked spasm incidence in patients with IHD was higher than in those with non-IHD but not significant (52.9% vs. 29.4%, p = 0.1114). Provoked positive spasm in the LCX in patients with rest angina and H-RCA was significantly higher than that in those without H-RCA (69.2% vs. 23.4%, p < 0.001). Provoked spasm on both left anterior descending artery and LCX in patients with rest angina and H-RCA was also remarkably higher than in those without H-RCA (53.8% vs. 3.1%, p < 0,001). There were no clinical differences between patients with and without H-RCA rest angina. Two-vessel spasm (61.5% vs. 0%, p < 0.01) and LCX-provoked spasm (69.2% vs. o%, p < 0.01) were significantly higher in patients with H-RCA and rest angina than that in those with H-RCA and effort angina. In patients with rest angina and H-RCA, LCX-positive spasm was significantly higher and these patients may have a potential of high disease activity in the clinic as a coronary spastic angina.

Acetylcholine spasm provocation test by trans-radial artery and brachial vein approach

BACKGROUND

Temporary pace maker is necessary because of transient block or bradycardia during the intracoronary acetylcholine spasm provocation tests based on the Japanese Circulation Society guidelines.

OBJECTIVES

We examined the feasibility and safety of the acetylcholine spasm provocation test via the radial artery and brachial vein approach.

METHODS

We tried to perform the acetylcholine spasm provocation tests in 252 patients via the radial artery and brachial vein approach procedures during 5 years. Acetylcholine was injected in incremental doses of 20/50/80 μg into the right coronary artery (RCA) and 20/50/100/200 μg into the left coronary artery (LCA). Back-up pacing rate was set at 40 beats/min. Positive spasm was defined as transient ≥90% luminal narrowing and ischemic electrocardiographic change or usual chest pain.

RESULTS

The procedure success of radial artery and brachial vein access was 94.4% (238/252) and 93.3% (235/252), respectively. We performed 221 patients (87.7%) with acetylcholine tests by radial artery and brachial vein approach. We changed to the brachial approach due to the failures of radial artery access in 14 patients. We also changed to the femoral vein in 11 patients and internal jugular vein in two patients. Back-up pace maker rhythm was observed in 92.1% (232/252) of all study patients, while it was significantly higher in the RCA testing than that in the LCA tests (84.9% (191/225) vs. 52.2% (131/251), P < 0.001). No irreversible complication was found.

CONCLUSIONS

We recommend the radial artery and brachial vein approach for safety and convenience when performing the acetylcholine spasm provocation tests.

Catheter-induced Spasm in the Proximal Right Coronary Artery

Objectives The clinical characteristics in patients with catheter-induced spasm in the proximal right coronary artery (RCA) are controversial. We performed a clinical analysis of catheter-induced spasm in the RCA. Methods We retrospectively analyzed 5,296 consecutive patients who underwent diagnostic or follow-up angiography during a 26-year period. During this period, we found 40 patients with catheter-induced spasm in the RCA. We compared the clinical characteristics and procedures of cardiac catheterization in patients with catheter-induced spasm in the RCA with those in patients without such spasm. Results The frequency of catheter-induced spasm in the RCA was 0.75% (40/5,296). We performed pharmacological spasm provocation tests in 36 of 40 patients after spasm relief. Positive spasm was observed in 32 patients (88.9%), and 25 patients (78.1%) had multiple spasms. The catheter procedures, including the approach sites (radial/brachial/femoral), catheter size (4/5/6Fr) and catheter type (Judkins right/Sones/Shared/Judkins left 3.5/Amplatz) were not markedly different between the two groups. A multivariate analysis showed that positive spasm [odds ratio (OR): 7.030, 95% confidence interval (CI): 1.920-25.700], a younger age (OR: 0.937, 95% CI: 0.910-0.965) and diabetes mellitus (OR: 0.278, 95% CI: 0.083-0.928) were the determinant factors for the catheter-induced spasm. Conclusion Approximately 80% of patients with catheter-induced spasm in the proximal RCA had coronary spastic angina. Positive provoked spasm was the most powerful determinant factor for catheter-induced spasm.

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.

Safety and usefulness of acetylcholine provocation test in patients with no culprit lesions on emergency coronary angiography

BACKGROUND

Vasospastic angina (VSA), which often causes acute coronary syndrome (ACS), can be diagnosed by intracoronary acetylcholine (ACh) provocation test. However, the safety and usefulness of ACh provocation test in ACS patients on emergency coronary angiography (CAG) compared to non-emergency settings are unclear.

METHODS

A total of 529 patients undergoing ACh provocation test during emergency or non-emergency CAG were included. Patients with resuscitated cardiac arrest were excluded. The primary endpoint was adverse events defined as a composite of death, ventricular fibrillation or sustained ventricular tachycardia, myocardial infarction, cardiogenic shock, cardiac tamponade, and stroke within 24 h after ACh provocation test.

RESULTS

There were no significant differences of the clinical characteristics between the groups of emergency (n = 84) and non-emergency (n = 445) ACh provocation test. The rate of positive ACh provocation test was similar between the 2 groups (50% vs. 49%, p = 0.81). Similarly, the incidence of adverse events in patients with emergency and non-emergency ACh provocation test did not significantly differ (1.2% vs. 1.3%, p = 1.00).

CONCLUSION

ACh provocation test can be safely performed in ACS patients with no obstructive culprit lesions on emergency CAG, and may be useful to diagnose VSA in those patients.

Sex-Related Differences in Vasomotor Function in Patients With Angina and Unobstructed Coronary Arteries

BACKGROUND

Coronary vasomotor dysfunction is an important mechanism for angina in patients with unobstructed coronary arteries.

OBJECTIVES

The purpose of this study was to determine sex differences in the prevalence and clinical presentation of vasomotor dysfunction in a European population and to examine sex differences in the dose of acetylcholine leading to a positive acetylcholine provocation test (ACH test).

METHODS

Between 2007 and 2014, we included 1,379 consecutive patients with stable angina, unobstructed coronaries and ACH test performed for epicardial vasospasm or coronary microvascular dysfunction (CMD) due to microvascular spasm. The predictive value of sex, risk factors, symptoms, and noninvasive test results was analyzed by means of logistic regression.

RESULTS

The mean patient age was 62 years, and 42% were male. There were 813 patients (59%) with a pathological ACH test, 33% for CMD and 26% for epicardial vasospasm. A pathological test was more common in females (70% vs. 43%; p < 0.001). In a multivariable logistic regression model the sex difference was statistically significant with a female-male odds ratio for CMD and epicardial vasospasm of 4.2 (95% confidence interval: 3.1 to 5.5; p < 0.001) and 2.3 (95% confidence interval: 1.7 to 3.1; p < 0.001), respectively. Effort-related symptoms, but neither risk factors nor noninvasive stress tests, contributed to predicting a pathological test. Female patients were more sensitive to acetylcholine with vasomotor dysfunction occurring at lower ACH doses compared with male patients.

CONCLUSIONS

Vasomotor dysfunction is frequent in patients with angina and unobstructed coronaries in a European population. Female patients have a higher prevalence of vasomotor dysfunction (especially CMD) compared with male patients. A pathological ACH test was observed at lower ACH doses in women compared with men.

Impact of pharmacological spasm provocation test in patients with a history of syncope

Coronary artery spasm is involved in the pathogenesis of various cardiac disorders. We investigated patients with a history of syncope who underwent elective coronary angiography. We retrospectively analyzed 5781 consecutive patients who had diagnostic or follow-up angiography during a 26-year period. During this period, we found 95 patients with a history of syncope before elective coronary angiography. Pharmacological spasm provocation testing was performed in 64 patients with a history of syncope (<1 year). Positive pharmacological response was observed in 48 patients, while the remaining 16 patients had negative tests. Positive spasm was defined as a transient ≥90% narrowing with ischemic electrocardiographic changes. Among the 64 patients, definite coronary spastic angina (CSA) was found in 35 patients (54.7%) and suspected CSA was found in 13 patients (20.3%). Among the 35 patients with definite CSA, 22 patients (62.9%) had chest symptoms before syncope, but 13 (37.1%) had no chest symptom before syncope. No difference in clinical characteristics was observed between the two groups. Focal spasm during pharmacological spasm provocation tests was significantly higher in patients with chest symptoms than in those without chest symptoms before syncope (54.3 vs. 12.0%, p < 0.002). CSA was observed in 75.0% of patients with a history of syncope (<1 year). Thirteen patients with definite CSA had neither chest pain nor chest pressure before syncope. We should therefore investigate coronary artery spasm as a potential etiology in patients with a history of syncope.

Relationships between more than 90% coronary luminal narrowing induced by ergonovine provocation test and ECG ischemic change as well as chest symptoms

In the clinic, patients with ≥90% luminal narrowing during ergonovine (ER) testing had variable response. We investigated ischemic findings and chest symptoms in patients with ≥90% luminal narrowing when performing ER tests, retrospectively. We performed 1210 ER tests over 26 years (1991-2016). We analyzed chest symptoms and positive ischemic ECG changes during ER tests. More than 90% luminal narrowing was found in 352 patients (29.1%) including 211 patients in the right coronary artery (RCA) and 217 patients in the left coronary artery (LCA). Chest symptom was observed in 290 patients (82.4%) including 162 patients in the RCA and 179 patients in the LCA. ST elevation was found in 154 patients including 98 in the RCA and 73 patients in the LCA, while ST depression was recognized in 81 patients including 38 patients in the RCA and 62 patients in the LCA. Two-third of patients with ≥90% luminal narrowing had significant ischemic ECG changes, whereas 60.5% of patients with ≥90% luminal narrowing complained usual chest pain accompanied with significant ischemic ECG changes. Unusual chest symptom was complained in 7.1% of patients with ≥90% luminal narrowing. Neither chest symptom nor ECG changes was found in 48 patients (13.6%) with ≥90% luminal narrowing. We should understand some limitation to diagnose positive coronary spasm during ER tests.

Outcomes of Brugada Syndrome Patients with Coronary Artery Vasospasm

Objective To evaluate the outcomes of patients with concomitant Brugada syndrome and coronary artery vasospasm. Methods Patients diagnosed with Brugada syndrome with an implantable cardiac defibrillator were retrospectively investigated, and the coexistence of vasospasm was evaluated. The clinical features and outcomes were evaluated, especially in patients with coexistent vasospasm. A provocation test using acetylcholine was performed in patients confirmed to have no organic stenosis on percutaneous coronary angiography to confirm the presence of vasospasm. Implantable cardiac defibrillator shock status was checked every three months. Statistical comparisons of the groups with and without vasospasm were performed. A univariate analysis was also performed, and the odds ratio for the risk of implantable cardiac defibrillator shock was calculated. Patients Thirty-five patients with Brugada syndrome, of whom six had coexistent vasospasm. Results There were no significant differences in the laboratory data, echocardiogram findings, disease, or the history of taking any drugs between patients with and without vasospasm. There were significant differences in the clinical features of Brugada syndrome, i.e. cardiac events such as resuscitation from ventricular fibrillation or appropriate implantable cardiac defibrillator shock. Four patients with vasospasm had cardiac events such as resuscitation from ventricular fibrillation and/or appropriate defibrillator shock; three of them had no cardiac events with calcium channel blocker therapy to prevent vasospasm. The coexistence of vasospasm was a potential risk factor for an appropriate implantable cardiac defibrillator shock (odds ratio: 13.5, confidence interval: 1.572-115.940, p value: 0.035) on a univariate analysis. Conclusion Coronary artery vasospasm could be a risk factor for cardiac events in patients with Brugada syndrome.

The acetylcholine administration time plays the key role for provoked spasm in the spasm provocation test

BACKGROUND

Acetylcholine (ACh) was administered for 3min in the ENCORE study, while the Japanese Circulation Society guidelines recommended the 20s ACh injection as an ACh test.

OBJECTIVES

We compared the ischemic findings between ACh administration for 3min and ACh injection for 20s in the same patients and in the same ACh doses without administration of nitrates in the left coronary artery.

METHODS

We investigated 30 patients with ischemic heart disease (25 men, 67±10 years, ACh 50μg: 3, ACh 100μg: 9, ACh 200μg: 18) by the above two ACh injection procedures. Temporary pacemaker was inserted and set at the rate of 40/min. Positive provoked spasm was defined as transient ≥90% narrowing and typical chest symptoms or ischemic electrocardiographic (ECG) changes.

RESULTS

Provoked spasm was observed in 22 patients with ACh 20s injection, while 10 patients had provoked spasm by ACh 3min administration (73.3% vs. 33.3%, p<0.05). Ischemic ECG changes (50.0% vs. 23.3%, p<0.05) and chest symptoms (73.3% vs. 43.3%, p<0.05) were significantly higher with ACh 20s injection than ACh 3min administration. Pacemaker rhythm was recognized in 19 patients with ACh 20s injection, whereas 7 patients with ACh 3min administration had a pacemaker rhythm (63.3% vs. 23.3%, p<0.01). Maximal ST elevation by ACh 20s injection was significantly higher than that by ACh 3min administration (0.47±0.94 vs. 0.13±0.51, p<0.05), while maximal ST depression was not different between the two procedures. Coronary artery diameter after ACh 20s injection was significantly lower than that after ACh 3min administration in the left anterior descending artery.

CONCLUSIONS

ACh administration procedures (3min or 20s injection) may influence the ischemic findings in spasm provocation testing.

Overview of the pharmacological spasm provocation test: Comparisons between acetylcholine and ergonovine

The spasm provocation tests of ergonovine and acetylcholine have been employed in the cardiac catheterization laboratory. Ergonovine acts through the serotogenic receptors, while acetylcholine acts through the muscarinic cholinergic receptors. Different mediators may have the potential to cause different coronary responses. However, there are few reports concerning the coronary response between ergonovine and acetylcholine in the same patients. Acetylcholine is supersensitive for females; spasm provoked by ergonovine is focal and proximal, whereas provoked spasm by acetylcholine is diffuse and distal. We should use both tests as supplementary in the clinic because ergonovine and acetylcholine have self-limitations to induce coronary spasms during daily life. The maximal pharmacological doses, administration methods, and the angiographical positive definition are remarkably different for each institution in the world. We recommend the pharmacological spasm provocation tests as Class I in the guidelines in patients with vasospastic angina throughout the world.

Overview of complications during pharmacological spasm provocation tests

Pharmacological spasm provocation tests are invasive methods and we always have the potential to encounter complications when performing these tests. In 1980, Buxton et al. reported three deaths when they performed intravenous ergonovine testing. However, we now employ the intracoronary ergonovine test instead of the intravenous injection of ergonovine from a safety procedure point of view. Past serious major complications of intravenous ergonovine tests, intracoronary ergonovine tests, and intracoronary acetylcholine tests were 0.31% (26/8419), 0.51% (11/2173), and 0.95% (148/15,527), respectively. Selective intracoronary testing had the serious major complications in 0.89% of patients including just one death (0.006%) and two acute myocardial infarctions (0.01%). Selective spasm provocation tests had no additional risks compared with performing diagnostic coronary angiography alone. In the Western countries, the pharmacological spasm provocation tests are not familiar in the clinic except for some specialized institutions. We need international clinical studies using the same protocol of spasm provocation tests to compare the frequency, clinical features, and prognosis of acetylcholine- or ergonovine-provoked coronary spasm between Western and Asian countries. And we hope that Western guidelines give spasm provocation testing a class I indication similar to Japanese Circulation Society guidelines because coronary artery spasm may have fewer racial differences and borders.

Sequential spasm provocation tests might overcome a limitation of the standard spasm provocation tests

OBJECTIVE

We examined the clinical usefulness of sequential spasm provocation tests as follows: first, acetylcholine (ACh) test, second, ergonovine (ER) test, and finally, the ACh test following the ER test.

PATIENTS AND METHODS

We performed the ACh and ER tests in 461 patients (294 men, 64.4±11.3 years of age) during a 23-year period. In addition, we administered an intracoronary injection of ACh after the ER tests in 240 patients. First, ACh [right coronary artery (RCA): 20/50/(80) μg, left coronary artery (LCA): 20/50/100/(200) μg] was administered incrementally over 20 s. Second, ER (RCA: 40 μg, LCA: 64 μg) was administered over 2-4 min. If a provoked spasm did not occur, we administered an intracoronary injection of ACh (50/80 μg into the RCA and 100/200 μg into the LCA) just after the ER tests. A positive spasm was defined as more than 99% transient luminal narrowing.

RESULTS

A positive spasm was observed in 221 (47.9%) patients including 181 ACh-positive (39.3%) and 119 ER-positive (25.8%) patients by the ACh or ER tests. In the 240 patients with a negative spasm in the ACh and ER tests, 48 (10.4%) patients developed provoked spasms on adding ACh after the ER test. The distributions of various cardiac disorders and provoked spasm vessels were similar among the three positive groups. Focal spasm was frequently observed in the ER-positive group, whereas diffuse spasm was frequently obtained in the ACh-positive group and by adding ACh after ER in the positive group. No major complications were recognized during the sequential spasm provocation tests.

CONCLUSION

Sequential spasm provocation tests might overcome a limitation of standard spasm provocation tests.

Patients With Coronary Endothelial Dysfunction Have Impaired Cholesterol Efflux Capacity and Reduced HDL Particle Concentration

RATIONALE

Coronary endothelial dysfunction (ED)-an early marker of atherosclerosis-increases the risk of cardiovascular events.

OBJECTIVE

We tested the hypothesis that cholesterol efflux capacity and high-density lipoprotein (HDL) particle concentration predict coronary ED better than HDL-cholesterol (HDL-C).

METHODS AND RESULTS

We studied 80 subjects with nonobstructive (<30% stenosis) coronary artery disease. ED was defined as <50% change in coronary blood flow in response to intracoronary infusions of acetylcholine during diagnostic coronary angiography. Cholesterol efflux capacity and HDL particle concentration (HDL-PIMA) were assessed with validated assays. Cholesterol efflux capacity and HDL-PIMA were both strong, inverse predictors of ED (P<0.001 and 0.005, respectively). In contrast, HDL-C and other traditional lipid risk factors did not differ significantly between control and ED subjects. Large HDL particles were markedly decreased in ED subjects (33%; P=0.005). After correction for HDL-C, both efflux capacity and HDL-PIMA remained significant predictors of ED status. HDL-PIMA explained cholesterol efflux capacity more effectively than HDL-C (r=0.54 and 0.36, respectively). The efflux capacities of isolated HDL and serum HDL correlated strongly (r=0.49).

CONCLUSIONS

Cholesterol efflux capacity and HDL-PIMA are reduced in subjects with coronary ED, independently of HDL-C. Alterations in HDL-PIMA and HDL itself account for a much larger fraction of the variation in cholesterol efflux capacity than does HDL-C. A selective decrease in large HDL particles may contribute to impaired cholesterol efflux capacity in ED subjects. These observations support a role for HDL size, concentration, and function as markers-and perhaps mediators-of coronary atherosclerosis in humans.

Approximately half of patients with coronary spastic angina had pathologic exercise tests

OBJECTIVES

We examined the clinical usefulness of treadmill exercise tests (TETs) in diagnosing coronary spastic angina (CSA).

METHODS

We performed the TETs and 24-h Holter monitoring in 300 CSA patients consisting of 152 patients with rest angina, 77 patients with effort angina, and 71 patients with rest and effort angina. Organic stenosis (>75%) was observed in 44 patients. Multiple spasms were recognized in 204 patients (68%).

RESULTS

Positive TETs were recognized in 113 patients (38%) and borderline was observed in 30 patients (10%). Positive response was significantly higher in patients with organic stenosis than those without fixed stenosis (63.6% vs. 33.2%, p<0.001). Moreover, ST elevation was more frequent in patients with organic stenosis than those without fixed stenosis (27.3% vs. 1.2%, p<0.001). Positive response in patients with effort angina (46.8%) was higher than those in patients with rest angina (33.6%) and rest and effort angina (36.6%), but not significant. Positive response was not different between single spasm and multiple spasms. In all 300 patients, ST segment elevation was observed in only four patients (1.3%) on the 24-h Holter monitoring.

CONCLUSIONS

TET was useful in documenting ischemia in patients with CSA. More than a third of patients with CSA had positive TETs. Moreover, we obtained the pathologic TET response in approximately half of patients with CSA.

Differential incidence and type of spasm according to coronary arterial location

BACKGROUND

We encounter a less provoked spasm in the left circumflex artery (LCX) by acetylcholine (ACh) testing compared with left anterior descending artery and right coronary artery (RCA) in the real world.

OBJECTIVES

We investigated the clinical characteristics of provoked spasm in the LCX by ACh testing.

METHODS

We retrospectively analyzed consecutive 1392 ACh testing over 20 years (1991-2011). The maximal ACh dose was 100 μg into the left coronary artery and 80 μg into the RCA. Positive spasm was defined as transient of more than or equal to 90% narrowing and usual chest symptoms or ischemic ECG changes.

RESULTS

Positive provoked spasm was recognized in 622 patients (44.7%) including 456 RCA spasms, 448 left anterior descending artery spasms, and 176 LCX spasms. LCX-provoked spasm was significantly lower than other vessels (P<0.001). LCX-provoked spasm was observed in 176 patients, of whom 113 patients (64.2%) had triple-vessel spasm, 46 patients (26.1%) had double-vessel spasm, and 17 patients (9.7%) had single-vessel spasm. More than 90% patients with LCX-provoked spasm had multiple spasms. Of 17 patients with LCX single-vessel spasm, 15 patients (88.2%) had focal spasm.

CONCLUSION

Under a maximal ACh dose of 100 μg into the left coronary artery, LCX-provoked spasm was significantly lower than other vessels and more than 90% of patients had multiple spasms.