Coronary artery spasm--clinical features, diagnosis, pathogenesis, and treatment. J Cardiol. 2008;51:2-17. [PMID: 18522770 DOI: 10.1016/j.jjcc.2008.01.001]

Evidence of myocardial scarring and microvascular obstruction on cardiac magnetic resonance imaging in a series of patients presenting with myocardial infarction without obstructed coronary arteries

Patients with acute chest pain, electrocardiographic ST-elevation and significant elevation of cardiac troponin but without obstructive coronary artery disease represent a diagnostic and therapeutic dilemma. Cardiac magnetic resonance imaging (CMR) can elucidate underlying alternative causes of troponin elevation including detection of (minor) myocardial infarction (MI) by identifying myocardial scarring as delayed enhancement. Of 77 patients, who were admitted between March 2009 and December 2012 with electrocardiographic (ECG) and biochemical evidence of acute MI without obstructive coronary artery disease, 45 patients underwent CMR that showed in 11/77 (14%) late gadolinium enhancement (LGE), compatible with myocardial scarring. We analyzed clinical, echocardiographic, and CMR data of these patients. Elevated troponin I levels were observed in all patients (median 1.3 ng/l, IQR 0.44-187) with median peak creatinine phosphokinase of 485 U/l (IQR 234-618). Echocardiographic wall motion abnormalities were detected in 8/11 (73%) patients; in 75% of these segments, ECG abnormalities were observed in corresponding leads. CMR detected LGE in the inferior (4/11), the inferolateral (5/11), the inferoseptal (2/11), the anterior (3/11), apical (3/11) and in the lateral segments (2/11). In addition, in all but two patients, these segments matched ECG abnormalities in corresponding leads. CMR identified microvascular obstruction in 4/11 (36%) patients. Patients with clinical, ECG, and biochemical signs of acute MI but unobstructed coronary arteries may have CMR-detectable myocardial scars. Information on myocardial scarring may help to make the diagnosis and draw therapeutic consequences. This case series underlines the value of contrast-enhanced CMR for myocardial tissue characterization.

Acute coronary syndrome in a patient with multifocal coronary vasospasm

Vasospastic angina results from temporary spasm of one or more coronary segments. Although prognosis of patients presenting with coronary vasospasm appears to be generally good, multivessel coronary vasospasm may increase the risk of life-threatening cardiac events. We present a case of a 51-year-old man admitted to the emergency room due to severe retrosternal pain, who was documented with multifocal coronary vasospasm. <Learning objective: The case described illustrates the importance of recognizing coronary vasospasm as a cause of reversible ischemia. Although vasospastic angina is associated with a favorable prognosis, multivessel involvement may increase the risk of life-threatening cardiac events.>.

Inappropriate Prescribing Among Elderly Home Care Patients in Japan

Background: Although several previous studies have examined the prevalence and risk factors associated with inappropriate prescribing (IP) among elderly patients, as identified by the Screening Tool of Older Persons’ potentially inappropriate Prescriptions (STOPP) and Screening Tool to Alert doctors to Right Treatment (START) criteria, no research has been conducted among elderly home care patients. Objective: This study aimed to explore the prevalence of IP and its risk factors as identified by the STOPP/START criteria among elderly home care patients in Japan. Study Design: Cross-sectional study. Setting: Home care settings in Japan. Participants: Eighty-nine patients aged 65 years or older who received regular home visiting services from Yamato Clinic between May 2013 and June 2013. Main Outcome Measure: The prevalence of IP and its risk factors as identified by the STOPP/START criteria. Results: Of the study population, 40.4% had at least one potentially inappropriate medication and 60.7% had at least one incidence of underprescribing. Risk factors for potentially inappropriate medications were hypertension, constipation, and polypharmacy, while those for underprescription were osteoporosis and polypharmacy. Conclusion: The prevalence of IP among elderly home care patients is high, with risk factors that include not only polypharmacy but also several specific underlying medical conditions.

Three cases of vasospastic angina that developed following the initiation of corticosteroid therapy

Three patients diagnosed as having remitting seronegative symmetrical synovitis with pitting edema syndrome, pemphigus erythematosus and idiopathic interstitial pneumonia were treated with oral prednisolone. Several weeks after starting the treatment, they experienced repeated chest pain attacks between midnight and early morning, although none of the patients had a past history of ischemic heart disease. One of the patients exhibited aggravation of symptoms soon after increasing the dose of prednisolone. A definitive diagnosis of vasospastic angina was made using electrocardiograms, coronary angiography and vasospasm provocation tests. These cases emphasize that clinicians should be aware of the possible occurrence of vasospastic angina following the initiation of corticosteroid therapy.

Heart failure in which coronary spasms played an important role

A 69-year-old woman was admitted for further examinations and treatment of chest pain. Emergency cardiac catheterization showed no significant stenosis on coronary angiograms; however, diffuse wall hypokinesis was observed on a left ventriculogram. After treating the patient's heart failure, cardiac catheterization was performed again. A spasm provocation test showed coronary spasms of the right and left coronary arteries. A right ventricular endomyocardial biopsy revealed denaturation and fibrosis of the myocardium under the endocardium, thus suggesting the presence of myocardial ischemia. This case highlights coronary spasms as a cause of heart failure.

Differences and interactions between risk factors for coronary spasm and atherosclerosis--smoking, aging, inflammation, and blood pressure

Objective Coronary spasm as well as atherosclerosis plays an important role in the pathogenesis of coronary heart disease. However, the relationship between coronary spasm and atherosclerosis is not well known. The purpose of the present study was to examine the differences and interactions between risk factors for coronary spasm and atherosclerosis and thereby explore the pathogenesis of coronary spasm. Methods The study subjects consisted of 938 patients with chest discomfort (522 men and 416 women, mean age 65.2±11.0) who underwent intracoronary-acetylcholine provocation tests for coronary spasm. Coronary risk factors, including age, gender, body mass index, blood pressure, high-sensitivity C-reactive protein (hsCRP), white blood cells, glucose, lipid profiles, and other laboratory chemistries were examined. Results Four hundred and ninety-six patients (315 men and 181 women, mean age: 65.1±11.4) were diagnosed with coronary spastic angina (CSA), while the remaining 442 patients (207 men and 235 women, mean age: 65.3±10.7) were diagnosed with non-CSA. A multiple logistic regression analysis revealed men, smoking, hsCRP, and low diastolic blood pressure (DBP) to be predictors (p=0.001, p=0.009, p=0.034, and p=0.041, respectively) for CSA, while age, diabetes mellitus, low high-density lipoprotein-cholesterol, systolic blood pressure (SBP), uric acid and male gender were found to be predictors (p<0.001, p<0.001, p<0.001, p=0.002, p=0.006 and p=0.029, respectively) for atherosclerosis. Conclusion Predictors for coronary spasm were smoking, hsCRP and low DBP, whereas those for atherosclerosis were age, diabetes mellitus, high SBP, and uric acid in that order. These findings suggest that the pathogenesis of coronary spasm differs from that of atherosclerosis.

Coronary artery spasm: review and update

Coronary artery spasm (CAS), an intense vasoconstriction of coronary arteries that causes total or subtotal vessel occlusion, plays an important role in myocardial ischemic syndromes including stable and unstable angina, acute myocardial infarction, and sudden cardiac death. Coronary angiography and provocative testing usually is required to establish a definitive diagnosis. While the mechanisms underlying the development of CAS are still poorly understood, CAS appears to be a multifactorial disease but is not associated with the traditional risk factors for coronary artery disease. The diagnosis of CAS has important therapeutic implications, as calcium antagonists, not β-blockers, are the cornerstone of medical treatment. The prognosis is generally considered benign; however, recurrent episodes of angina are frequently observed. We provide a review of the literature and summarize the current state of knowledge regarding the pathogenesis of CAS.

Myocardial infarction with normal coronaries: an unexpected finding in a 13-year-old girl with systemic lupus erythematosus

We report a 13-year-old girl diagnosed with systemic lupus erythematosus (SLE) who presented with left-sided chest pain, with ECG changes and elevation troponins that were suggestive of an acute inferior wall myocardial infarction (MI). Her multi-slice computed tomography coronary angiogram and standard angiogram were normal. The cardiac magnetic resonance imaging revealed an area of infarcted myocardium that was in the right coronary artery territory. We believe her MI was most likely secondary to coronary vasospasm. MI is rare and coronary vasospasm is an uncommon cause of MI in children and adolescents with SLE.

Syncope caused by coronary artery spasm without chest pain leading to ventricular fibrillation

We present a case of syncope caused by coronary artery spasm without chest pain leading to ventricular fibrillation despite of vasodilator therapy with a calcium channel blocker (CCB). A 68-year-old man presented with two episodes of syncope without chest pain. Ergonovine provocation test induced a diffuse spasm in the right coronary artery (RCA) and subsequently, ventricular fibrillation. Under the therapy with multiple vasodilators including two CCBs, a second ergonovine provocation induced a spasm of the proximal RCA resulting in complete obstruction. Owing to drug-resistant coronary spasm complicated by ventricular fibrillation, an implantable cardioverter defibrillator (ICD) was implanted. This case report highlights the occurrence of syncope caused by coronary artery spasm without chest pain that was refractory to single CCB therapy and needed ICD implantation. Therapy with multiple vasodilators, including two or more CCBs, along with ICD implantation may be required to treat such refractory coronary artery spasms leading to lethal arrhythmia.

Coronary spasm and acute myocardial infarction due to a mutation (V734I) in the nucleotide binding domain 1 of ABCC9

BACKGROUND

Alterations in coronary vasomotor tone may participate in the pathogenesis of acute myocardial infarction (AMI). Vascular ATP-sensitive K(+) (KATP) channels, formed by Kir6.x/SUR2B, are key regulators of coronary tone and mutations in cardiac (Kir6.2/SUR2A) KATP channels result in heart disease. Here we explore the pathophysiological mechanism of a rare mutation (V734I) found in exon 17 of the ABCC9 gene, estimated to cause a 6.4-fold higher risk of AMI before the age of 60.

METHODS AND RESULTS

Eleven patients carrying the mutation were identified; they presented AMI of vasospastic origin associated with increased plasma levels of endothelin-1 and increased leukocyte ROCK activity. The effects of the mutation on the functional properties of the two splice variants of ABCC9 (SUR2A and SUR2B) were studied using patch-clamp electrophysiology. The mutation reduced the sensitivity to MgATP inhibition of Kir6.2/SUR2B channels but not of Kir6.2/SUR2A and Kir6.1/SUR2B channels. Furthermore, the stimulatory effects of MgNDP (MgADP, MgGDP and MgUDP) were unaltered in mutant Kir6.2/SUR2A and Kir6.1/SUR2B channels. In contrast, mutant channels composed of Kir6.2 and SUR2B were less sensitive to MgNDP activation, assessed in the presence of MgATP. The antianginal drug nicorandil activated Kir6.2/SUR2B-V734I channels, thus substituting for the loss of MgNDP stimulation, suggesting that this drug could be of therapeutic use in the treatment of AMI associated with V734I.

CONCLUSIONS

The 734I allele in ABCC9 may influence susceptibility to AMI by impairing the response of vascular, but not cardiac, KATP channels to intracellular nucleotides. This is the first human mutation in an ion channel gene to be implicated in AMI.

Effects of Low Dose versus High Dose Statin Therapy on the Changes of Endothelial Function and Carotid Intima-Media Thickness in Patients with Variant Angina

BACKGROUND

To compare the effects of low dose and high dose of statin treatment on endothelial function and carotid intima-media thickness (IMT) in patients with variant angina (VAP).

METHODS

A total of 70 patients with VAP were divided into two groups; atorvastatin 10 mg treatment group (group I: n = 35, 54.2 ± 12.5 years) versus atorvastatin 40 mg treatment group (group II: n = 35, 52.6 ± 9.8 years). Flow mediated vasodilation (FMD) of the brachial artery and IMT of the carotid artery were compared between the groups after 6 months of statin treatment.

RESULTS

The baseline FMD and carotid IMT were not different between the groups. After 6 months of statin therapy, FMD was significantly improved in both groups (7.7 ± 2.5% to 8.9 ± 2.2% in group I, p = 0.001, 7.9 ± 2.7% to 9.5 ± 2.8% in group II, p < 0.001), but the degree of FMD change and FMD at 6 month were not different between the groups. Carotid IMT were not changed in both groups after 6 months of statin therapy.

CONCLUSION

The use of statin for 6 months significantly improved endothelial function in patients with VAP, but carotid IMT was not changed. The use of high dose statin did not show significant additional benefit as compared with the use of low dose statin. The present study suggested that statin therapy would be beneficial in the treatment of VAP.

Spontaneous coronary artery spasm accidentally detected by 320-row multi-detector computed tomography

A 64-year-old woman was introduced to our hospital suspected of having angina pectoris. A 12-lead electrocardiogram showed negative T wave in inferior leads. An echocardiography revealed no abnormality. In 320-row multi-detector computed tomography (MDCT), a severe narrowing of the right coronary artery was detected with collateral vessels between the distal portion of the obstructed right coronary artery and the left anterior descending artery. Coronary angiography showed no stenosis of the right coronary artery and non-obstructive plaques in the left coronary artery. To provoke coronary artery spasm, acetylcholine was infused into the left coronary artery. But, no narrowing was inducible in the left coronary artery. After that, a spasm of the right coronary artery was observed without the injection of acetylcholine into the right coronary artery. The spasm was located in the same site as the narrowing on MDCT imaging. A calcium channel antagonist (benidipine hydrochloride 8 mg/day) and a nitrate (isosorbide dinitrate 80 mg) were effective for coronary artery spasm. <Learning objective: Multi-detector computed tomography (MDCT) imaging is useful for examining coronary artery disease. In addition to evaluating coronary organic stenosis, 320-row MDCT could detect spontaneous coronary artery spasm. Although coronary artery spasm has to be taken into account, intracoronary injection of acetylcholine is necessary to diagnose coronary artery spasm.>.

A special case of Wellens' syndrome

Wellens' syndrome is a pattern of electrocardiographic T-wave changes associated with critical stenosis of proximal left anterior descending artery (LAD). T-waves abnormalities were found in precordial leads, especially in V2-V3 during pain-free periods, and ECG obtained during episodes of pain demonstrates upright T-waves with possible elevated or isoelectric ST segments. Early recognition and appropriate intervention carries significant diagnostic and prognostic value. We reported a case of Wellens' syndrome with different etiology and prognosis. Although the ECG showed typical T-wave changes in V2-V5 leads, patient's coronary angiography revealed moderate stenosis in proximal LAD, and coronary artery spasm was suggested. Unlike the classic Wellens' syndrome, which needs aggressive coronary intervention, our patient fared well with conservative medical therapy (diltiazem and nitrates) and showed favorable prognosis.

Coronary plaque component in patients with vasospastic angina: a virtual histology intravascular ultrasound study

BACKGROUND

Coronary spasm plays an important role in the pathogenesis of ischemic heart disease. However, tissue components of coronary plaque in patients with vasospastic angina (VSA) have been unknown. This study used virtual histology (VH)-intravascular ultrasound (IVUS) to elucidate the tissue component of spastic coronary arteries and its gender differences in patients with VSA.

METHODS

According to acetylcholine provocation tests, the study subjects (42 patients [19 men, 23 women, 61 ± 13 years]) were divided into 2 groups: the VSA group of 26 patients and the non-VSA group of 16 patients. After nitrate injection, IVUS volumetric analysis was done, and the parameters were compared between the groups.

RESULTS

Although clinical demographics were almost identical between the groups, VSA group had lower plasma adiponectin level (5.9 ± 3.3 μg/ml vs. 11.2 ± 7.6 μg/ml, p=0.007) and tended to have higher high-sensitivity C-reactive protein (0.15 ± 0.24 mg/dl vs. 0.06 ± 0.04 mg/dl, p=0.1) than non-VSA group. VSA group had diffusely thickened intima (% plaque volume, 34 ± 11% vs. 27 ± 7%, p=0.01) compared with non-VSA group. However, plaque components of patients with VSA were similar with that of non-VSA patients (dense calcium, 4 ± 6% vs. 3 ± 4%; necrotic core, 10 ± 9% vs. 8 ± 6%; fibrofatty, 19 ± 16% vs. 22 ± 11%; and fibrous, 67 ± 16% vs. 67 ± 9%). Although male patients with VSA had atherogenic lipid and metabolic profiles than female VSA patients, there were no significant gender differences in the volumetric IVUS parameters and plaque components.

CONCLUSIONS

Compared with non-VSA patients, VSA patients had diffusely thickened fibrous-dominant coronary plaque without gender difference, and that might suggest the role of vasospasm in the development of atherosclerosis.

Evaluation of coronary microvascular function in patients with vasospastic angina

AIM: To investigate endothelium-dependent and -independent coronary microvascular functions in patients with vasospastic angina (VSA).

METHODS: Thirty-six patients with VSA (30 men and 6 women; mean age, 58 years) were enrolled in this study. VSA was defined as ≥ 90% narrowing of the epicardial coronary arteries on angiography performed during a spasm provocation test, presence of chest pain, and/or ST-segment deviation on an electrocardiogram (ECG). Patients (n = 36) with negative spasm provocation test results and those matched for age and sex were enrolled as a control group (nonVSA group). Low-dose acetylcholine (ACh; 3 μg/min) was infused into the left coronary ostium for 2 min during the spasm provocation test. Following the spasm provocation test, nitroglycerin (0.2 mg) was administered intracoronally. Coronary blood flow (was calculated from quantitative angiography and Doppler flow velocity measurements, and the coronary flow reserve was calculated as the ratio of coronary flow velocity after injection of adenosine triphosphate (20 μg) to the baseline value. Changes in the coronary artery diameter in response to ACh and nitroglycerin infusion were expressed as percentage changes from baseline measurements.

RESULTS: Body mass index was significantly lower in the VSA group than in the nonVSA group. The frequency of conventional coronary risk factors and the rate of statin use were similar between the 2 groups. The left ventricular ejection fraction as evaluated by echocardiography was similar between the 2 groups. The duration of angina was 9 ± 2 mo. The results of blood chemistry analysis were similar between the 2 groups. Low-dose ACh did not cause coronary spasms. The change in coronary artery diameter in response to ACh was lower in the VSA group (-1.4% ± 9.3%) than in the nonVSA group (3.1% ± 6.5%, P < 0.05), whereas nitroglycerin-induced coronary artery dilatation and coronary blood flow increase in response to ACh or coronary flow reserve did not differ significantly between the 2 groups.

CONCLUSION: These findings suggest that microvascular coronary function may be preserved despite endothelial dysfunction of the epicardial coronary arteries in patients with VSA.

Alcohol flushing and positive ethanol patch test in patients with coronary spastic angina: possible role of aldehyde dehydrogenase 2 polymorphisms

OBJECTIVE

Coronary spasm plays an important role in the pathogenesis of coronary heart disease (CHD) and angina pectoris caused by coronary spasm or coronary spastic angina (CSA) is prevalent in Japan. However, the precise mechanisms underlying coronary spasm are unclear. Alcohol intolerance is prevalent among East Asians, and we previously reported that coronary spasm could be induced by alcohol intake in CSA patients. We herein examined whether CSA is associated with alcohol intolerance in Japanese subjects.

METHODS

The study subjects consisted of 80 CSA patients (57 men/ 23 women, mean age 62 ± 12) and 52 non-CSA patients (25 men/27 women, mean age 63 ± 10). The ethanol patch test (EPT) and questionnaire which evaluates flushing after ethanol intake, along with an examination of clinical features and laboratory chemistry data for CHD risk factors were done. Gender (male) and smoking were higher (p=0.007, and p=0.019, respectively) and plasma HDL cholesterol level was lower (p=0.035) in the CSA patients than in the non-CSA patients. Multivariable logistic regression analysis including age, EPT, smoking, and plasma HDL cholesterol level as independent variables revealed that positive EPT and smoking were significant predictors of CSA (p=0.011 and p=0.016, respectively).

CONCLUSION

Positive EPT and alcohol flushing following alcohol intake, as well as smoking and plasma levels of HDL cholesterol, were significantly associated with CSA in Japanese patients. Therefore, alcohol ingestion as well as smoking is a significant risk factor for CSA in Japanese.

Clinical outcome of coronary stenting in patients with variant angina refractory to medical treatment: a consecutive single-center analysis

OBJECTIVE

To investigate the efficacy of coronary stenting in patients with variant angina refractory to medical treatment.

SUBJECTS AND METHODS

Variant angina was diagnosed in 81 patients admitted to the Department of Cardiology between January 2003 and June 2011. However, coronary stenting was performed in 21 patients refractory to medical treatment, but coronary angiography and intravascular ultrasound were performed in all patients, and acetylcholine provocative test was performed in 11 of the 21 patients refractory to medical treatment. Coronary angiography was repeated after 9-12 months in the 21 patients with coronary stents. Clinical follow-up time was 2.5 ± 3.1 years (range 1-8).

RESULTS

Of the 81 patients, coronary angiography and intravascular ultrasound did not reveal significant stenosis in 13 (16.0%), but revealed 20-75% fixed stenosis in the remaining 68 (84.0%) patients. The acetylcholine provocative test was positive in the 11 patients. Of the 21 patients with coronary stents, the spasm site was located in the right coronary artery in 16 (76.2%) and in the left anterior descending artery in the remaining 5 (23.8%) patients. During the 1- to 8-year follow-up period, 1 of the 21 patients with stents developed recurrent episodes of variant angina, 5 patients had occasional chest pain, and the other 15 were asymptomatic. Coronary angiography at 9-12 months after initial evaluation demonstrated no stenosis in 3 patients, 20-40% in-stent mild intimal hyperplasia in 15 patients, and 50-80% in-stent restenosis in 3 patients. Coronary stenting was performed again in 2 patients.

CONCLUSIONS

The present study showed that coronary stenting for severe refractory coronary vasospasm was effective and without serious complications. It can be an alternative and viable option for some patients who are refractory to medical therapy and at a high risk of acute coronary syndrome recurrence.

Coronary vasospasm while treating supraventricular tachycardia: is adenosine really to blame?

Coronary artery spasm has been reported during adenosine stress testing. Herein, we describe a transient ST-segment elevation following adenosine therapy for supraventricular tachycardia. A 38-year-old male presented to the emergency department with palpitations. Electrocardiogram showed supraventricular tachycardia with short RP interval. Vagal maneuvers were unsuccessful. Adenosine was then administered in two successive injections of 6 and 12 mg dosages, respectively. A subsequent 12-lead electrocardiogram revealed ST-segment elevation in inferior leads with reciprocal changes. Coronary angiography disclosed nonobstructive coronary disease. A postprocedure electrocardiogram exhibited normal sinus rhythm with nonspecific T wave abnormalities. Cardiac biomarkers were elevated with a peak troponin I of 0.32. Echocardiogram depicted bicuspid aortic valve and normal systolic function. Electrophysiological study revealed a concealed left accessory pathway and successful radiofrequency ablation was performed. Given the dynamic changes in the electrocardiogram, we hypothesize that this event was most likely a coronary vasospasm. The mechanism of coronary spasm following adenosine injection remains uncertain. Potential mediators include K_ATP channels and adenosine-2 receptors.

Microvascular coronary artery spasm presents distinctive clinical features with endothelial dysfunction as nonobstructive coronary artery disease

Background

Angina without significant stenosis, or nonobstructive coronary artery disease, attracts clinical attention. Microvascular coronary artery spasm (microvascular CAS) can cause nonobstructive coronary artery disease. We investigated the clinical features of microvascular CAS and the therapeutic efficacy of calcium channel blockers.

Methods and Results

Three hundred seventy consecutive, stable patients with suspected angina presenting nonobstructive coronary arteries (<50% diameter) in coronary angiography were investigated with the intracoronary acetylcholine provocation test, with simultaneous measurements of transcardiac lactate production and of changes in the quantitative coronary blood flow. We diagnosed microvascular CAS according to lactate production and a decrease in coronary blood flow without epicardial vasospasm during the acetylcholine provocation test. We prospectively followed up the patients with calcium channel blockers for microvascular coronary artery disease. We identified 50 patients with microvascular CAS who demonstrated significant impairment of the endothelium-dependent vascular response, which was assessed by coronary blood flow during the acetylcholine provocation test. Administration of isosorbide dinitrate normalized the abnormal coronary flow pattern in the patients with microvascular CAS. Multivariate logistic regression analysis indicated that female sex, a lower body mass index, minor–borderline ischemic electrocardiogram findings at rest, limited–baseline diastolic-to-systolic velocity ratio, and attenuated adenosine triphosphate–induced coronary flow reserve were independently correlated with the presence of microvascular CAS. Receiver-operating characteristics curve analysis revealed that the aforementioned 5-variable model showed good correlation with the presence of microvascular CAS (area under the curve: 0.820). No patients with microvascular CAS treated with calcium channel blockers developed cardiovascular events over 47.8±27.5 months.

Conclusions

Microvascular CAS causes distinctive clinical features and endothelial dysfunction that are important to recognize as nonobstructive coronary artery disease so that optimal care with calcium channel blockers can be provided.

Clinical Trial Registration

URL: www.umin.ac.jp/ctr. Unique identifier: UMIN000003839.

[Severe coronary vasospasm]

A 50-year-old man, with chronic kidney disease and on dialysis, underwent coronary angiography in the context of acute coronary syndrome, which revealed focal lesions (type A) in the proximal left anterior descending and mid circumflex arteries. Ad-hoc angioplasty was performed on both lesions with direct stenting. An immediate drop in arterial blood pressure was observed and the angiogram showed new lesions with reduced flow throughout the coronary tree, progressing to cardiogenic shock and electromechanical dissociation. During cardiopulmonary resuscitation maneuvers, intracoronary verapamil was administered and TIMI 3 flow, sinus rhythm and a rise in blood pressure were obtained. Clinical stability was progressively restored. The patient was discharged medicated with calcium channel blockers and nitrates. During follow-up, he was twice readmitted for unstable angina. Coronary angiography revealed findings that could easily have been interpreted as new obstructive lesions, but these resolved after administration of intracoronary nitrates.

Rho-associated kinase 2 polymorphism in patients with vasospastic angina

Background and Objectives

Recent studies indicate that in response to vasoconstrictor stimuli, the small GTPase RhoA and its down-stream effector, Rho-associated kinase 2 (ROCK)/Rho-kinase, are associated with hypercontraction of the vascular smooth muscle of coronary arteries through augmentation of myosin light chain phosphorylation and Ca²⁺ sensitization. Expression of ROCK/Rho-kinase mRNA was significantly increased and up-regulated in the spastic coronary artery in a porcine model, and a specific inhibitor of ROCK/Rho-kinase inhibited coronary artery spasm in humans. We therefore explored the role of ROCK2 polymorphisms in the pathogenesis of vasospastic angina (VA).

Subjects and Methods

We studied 106 patients with VA who exhibited spontaneous or provoked coronary spasm during coronary angiography and compared the prevalence of ROCK2 polymorphisms between this group of patients with VA and controls whose angiograms were normal, and in whom the ergonovine test did not cause spasm (n=107). Five single nucleotide polymorphisms (SNPs) of the ROCK2 gene were selected. SNPs were genotyped by high-resolution melting. Linkage disequilibrium and haplotype analyses were performed using the SHEsis program.

Results

The prevalence of genotypes of the 5 interesting SNPs in patients with VA was not different from that in the control group. In haplotype analysis, the haplotype G-T-C-T-G (in order of rs978906, rs2271621, rs2230774, rs1515210, and rs3771106) was significantly associated with a decreased risk of VA (p=0.007).

Conclusion

The haplotype G-T-C-T-G in the ROCK2 gene had a protective effect against VA, suggesting the involvement of ROCK2 in VA pathogenesis.

Therapeutic procedures for coronary vasospasm-induced polymorphic ventricular tachycardia

Coronary vasospasm is an unusual cause of angina and myocardial ischemia, with the potential to provoke acute myocardial infarction, malignant cardiac arrhythmias, and sudden cardiac death. The diagnosis is largely clinical and requires a high index of suspicion. Provocation studies are rarely performed due to the risks of the procedure and the relatively low incidence of disease. A subset of patients does not respond to conventional medical therapy and a paucity of evidence exists to guide therapy. While generally believed a multifocal phenomenon, there have been reports of successful treatment of focal, refractory vasospasm with coronary stent implantation. Furthermore, consideration of an implantable cardioverter defibrillator is warranted when vasospasm is complicated by lethal ventricular arrhythmias.

Increased leukocyte Rho-associated coiled-coil containing protein kinase activity predicts the presence and severity of coronary vasospastic angina

OBJECTIVE

Although inhibition of Rho-associated coiled-coil containing protein kinase (ROCK) has been shown to prevent coronary vasospastic angina (CVA), direct evidence linking ROCK activity and CVA is lacking. Accordingly, we investigated whether ROCK activity is an independent marker for CVA and is altered after treatment with antispastic medications.

METHODS AND RESULTS

We prospectively studied 31 Taiwanese patients who were diagnosed with CVA and 33 control subjects. Subject demographics were recorded, and blood samples were obtained at baseline in all participants and in CVA patients after 3 months of antispastic treatment. Compared with control subjects, leukocyte ROCK activity was greater in CVA patients (136% versus 91%, P<0.001). A cutoff value for leukocyte ROCK activity of 104% predicted the presence of CVA with specificity and sensitivity rates of 88% and 84%, respectively. ROCK activity increased with the severity of CVA (P for trend<0.001). Following 3-month treatment of antispastic agents, leukocyte ROCK activity, high-sensitivity C-reactive protein, and interleukin-6 levels were reduced by 43%, 42% and 27%, respectively (P<0.05 for all).

CONCLUSIONS

Increased levels of leukocyte ROCK activity independently predicted the presence of CVA and correlated with CVA severity. Treatment with antispastic agents substantially reduced the level of leukocyte ROCK activity.

Coronary vasospastic angina: assessment by multidetector CT coronary angiography

Objective

We aimed to describe the imaging findings of multidetector CT coronary angiography (MDCTA) in cases of vasospastic angina (VA) and to determine the accuracy of MDCTA in the identification of VA as compared with invasive coronary angiography with an ergonovine provocation test (CAG with an EG test).

Materials and Methods

Fifty-three patients with clinically suspected VA were enrolled in this study. Two radiologists analyzed the stenosis degree, presence or absence of plaque, plaque composition, and a remodeling index of the related-segment in CAG with an EG test, which were used as a gold standard. We evaluated the diagnostic performances of MDCTA by comparing the MDCTA findings with those of CAG with an EG test.

Results

Among the 25 patients with positive CAG with an EG test, all 12 patients with significant stenosis showed no definite plaque with the negative arterial remodeling. Of the six patients with insignificant stenosis, three (50%) had non-calcified plaque (NCP), two (33%) had mixed plaque, and one (17%) had calcified plaque. When the criteria for significant stenosis with negative remodeling but no definite evidence of plaque as a characteristic finding of MDCTA were used, results showed sensitivities, specificities, positive predictive values (PPV), and negative predictive values (NPV) of 48%, 100%, 100%, and 68%, respectively.

Conclusion

Significant stenosis with negative remodeling, but no definite evidence of plaque, is the characteristic finding on MDCTA of VA. Cardiac MDCTA shows good diagnostic performance with high specificity and PPV as compared with CAG with an EG test.

An Overview on Coronary Heart Disease (A Comparative Evaluation of Turkey and Europe) and Cost-effectiveness of Diagnostic Strategies

OBJECTIVE

Coronary heart disease (CHD) is the leading cause of death for men and women in Turkey as it is in Europe and US. The prevalence of the disease is 3.8% in Turkey and 200,000 patients are added to the pool of CHD annually Because of genetic predisposition and high proportions of physical inactivity, smoking habit, and obesity, CHD is encountered in earlier ages in our country So, the economic burden of the disease is expected to be relatively high, but the amount of health expenditure is not always parallel to the prevalence of a disease in the community. This article was written to overview CHD statistics to make a comparison between Turkey and some European countries and to investigate the value of myocardial perfusion scan (MPS) as a gatekeeper in diagnosing CHD before invasive coronary angiography (ICA). The consequences were evaluated for Turkey In diagnosis; noninvasive testing gains importance in connection with the new approaches in treatment strategies, because a direct ICA strategy results in higher rates of revascularization without improvement in clinical outcomes. A "gatekeeper" is needed to select the patients who are not required to undergo angiography. MPS with its proved power in diagnosis and predicting prognosis, provides a cost-effective solution, and is accepted in some extensive analyses as a "gatekeeper" particularly in intermediate and high risk patients and in patients with known CHD. In conclusion, MPS may provide an optimal solution better than the ongoing situation in Turkey as well, when it is approved as a "gatekeeper in an algorithm before ICA.

CONFLICT OF INTEREST

None declared.

Enhanced Rho-kinase activity in circulating neutrophils of patients with vasospastic angina: a possible biomarker for diagnosis and disease activity assessment

OBJECTIVES

The aim of this study was to examine whether Rho-kinase activity is systemically enhanced in patients with vasospastic angina (VSA) and, if so, whether a noninvasive diagnostic method could be developed to improve practice.

BACKGROUND

The activated Rho-kinase pathway plays a central role in the molecular mechanism of coronary vasospasm in animal models and patients with VSA. Recently, it has been reported that Rho-kinase activity in circulating leukocytes is associated with various diseases.

METHODS

Fifty-three consecutive patients with chest pain who underwent acetylcholine provocation testing for coronary spasm were examined. Patients were divided into 2 groups depending on their response to the test: VSA (n = 33) and non-VSA (n = 20) groups. Venous blood samples were collected to measure Rho-kinase activity in circulating neutrophils, determined by the extent of phosphorylation of myosin-binding subunit (MBS), a substrate of Rho-kinase.

RESULTS

Rho-kinase activity was significantly higher in the VSA group than in the non-VSA group (phosphorylated MBS/total MBS ratio 1.33 ± 0.37 vs. 0.95 ± 0.22, p < 0.001). In the VSA group, no correlation was noted between Rho-kinase activity and high-sensitivity C-reactive protein, smoking, or accumulated number of coronary risk factors. After the 3-month medical treatment, Rho-kinase activity in the VSA group was significantly decreased to 1.08 ± 0.31 (p < 0.001). On receiver-operating characteristic curve analysis, a phosphorylated MBS ratio of 1.18 was identified as the best cutoff level to predict the diagnosis of VSA.

CONCLUSIONS

These results indicate that Rho-kinase activity in circulating neutrophils is enhanced in patients with VSA and may be a useful biomarker for diagnosis and disease activity assessment of the vasospastic disorder.

Variant angina and coronary artery spasm: the clinical spectrum, pathophysiology, and management

Variant angina is a form of angina pectoris that shows transient ST-segment elevation on electrocardiogram during an attack of chest pain. Ischemic episodes of variant angina show circadian variation and often occur at rest from midnight to early morning. Ischemic episodes also occur during mild exercise in the early morning. However, they are not usually induced by strenuous exercise in the afternoon. Other important clinical features of variant angina include the high frequency of asymptomatic ischemic episodes and the syncope that sometimes occur during the ischemic episodes. Syncope is due to severe arrhythmias, including ventricular tachycardia, ventricular fibrillation, and high-degree atrioventricular block. Coronary artery spasm is the mechanism of ischemic episodes in variant angina. The incidence of coronary artery spasm shows a racial difference and is higher in Japanese than in Caucasians. Coronary arteriograms are normal or near-normal in most Japanese patients with variant angina. Deficient basal release of nitric oxide (NO) due to endothelial dysfunction, and enhanced vascular smooth muscle contractility with the involvement of the Rho/Rho-kinase pathway are reported to play important roles in the pathogenesis of coronary artery spasm. Other precipitating factors of coronary artery spasm include imbalance in autonomic nervous activity, increased oxidative stress, chronic low-grade inflammation, magnesium deficiency, and genetic susceptibility. The genetic risk factors associated with coronary artery spasm include gene polymorphisms of endothelial NO synthase (NOS), paraoxonase, and other genes. Calcium channel blockers are extremely effective in preventing coronary spasm. The long-acting nitrate, nicorandil, and Rho-kinase inhibitor are also useful for inhibiting coronary artery spasm. Because variant angina can lead to acute myocardial infarction, fatal arrhythmias, and sudden death, early treatment is important. The prognosis of patients with variant angina is favorable, if early complications can be overcome. However, because coronary artery spasm cannot be suppressed in some patients, even with multiple medications, medications to suppress intractable coronary artery spasm must be developed.