Limitations of medical therapy in patients with pure coronary spastic angina

A Case of Refractory Variant Angina

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

What is the meaning of provoked spasm phenotypes by vasoreactivity testing?

Coronary artery epicardial spasm is involved in the pathogenesis of many cardiac disorders. Vasoreactivity testing, such as intracoronary injection of acetylcholine (ACH) or ergonovine (ER), is the gold standard method for the diagnosis of vasospastic angina. Provoked epicardial spasm phenotypes are classified as focal spasm and diffuse spasm. Multiple factors, including sex, ethnicity, and use of coronary vasoactive stimulators, are related to the provoked phenotypes of epicardial spasm. Diffuse-provoked spasm is often observed in females, where focal-provoked spasm is markedly more common in males. ACH provokes more diffuse and distal spasms, whereas ER induces more focal and proximal spasms. Yellow plaque and coronary thrombi are often observed in lesions with focal spasms, and intimal thickness with a sonolucent zone is significantly more common in lesions with focal spasm. Furthermore, clinical outcomes in patients with focal spasm are unsatisfactory compared with those in patients with diffuse spasm. However, the reproducibility and eternality of provoked spasm phenotypes by vasoreactivity testing is uncertain. Coronary atherosclerosis or endothelial damage may affect coronary vasomotor tone. Although coronary artery spasm may persist in the same coronary artery, provoked coronary spasm phenotypes may exhibit a momentary coronary reaction by intracoronary ACH or ER testing.

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.

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.

Do Patients with Myocardial Infarction with Non-Obstructive Coronary Arteries Have Similar Prognosis Compared to Ones with MI-CAD?

Acute myocardial infarction (AMI) is a leading cause of morbidity and mortality worldwide and it is primarily caused by acute plaque disruption and coronary occlusion. Recent studies suggest that myocardial infarction with non-obstructive coronary arteries (MINOCA) also occurs but the underlying mechanisms have not been fully understood until recently. The evidence also suggests that the clinical outcomes of patients presenting with MINOCA are similar to AMI patients with obstructive coronary artery disease (MI-CAD), including all-cause mortality and major adverse cardiovascular events. The present narrative review considers the risk factors, pathological changes, and outcomes associated with MINOCA and compares them with MI-CAD.

Assessment of coronary spasms with transluminal attenuation gradient in coronary computed tomography angiography

Purpose

To evaluate the imaging features of coronary spasm, including transluminal attenuation gradient (TAG) on coronary computed tomography angiography (CCTA), in patients with vasospastic angina (VA).

Methods

A total of 43 patients with a high clinical likelihood of VA were included in the study. All the subjects underwent double CCTA acquisition: CCTA without a vasodilator (‘baseline CT’) and CCTA during continuous intravenous nitrate infusion (‘IV nitrate CT’). A catheterized ergonovine provocation test was used to determine true VA patients. Coronary spasm is classified into focal- and diffuse-types according to morphological differences. We measured TAG and contrast enhancement of the proximal ostium (ProxHU) of each coronary artery for both the baseline and IV nitrate CT.

Results

Twenty-four patients (55.8%) showed positive results of coronary vasospasm on the provocation test. Thirty-eight vessels showed coronary spasms (29.5%): Focal-type in nine vessels (24%), and diffuse-type in 29 (76%). In the baseline CT, LCX showed significantly lower (steeper) TAG in spasm(+) vessels than in spasm(-) vessels, while LAD and RCA showed no significant differences in TAG. The ProxHU of LAD showed significantly lower values in spasm(+) vessels than in spasm(-) vessels, while the other vessels did not show significant differences in ProxHU. For IV nitrate CT, there were no significant differences in either the TAG and ProxHU between spasm(+) and (-) vessels for all the three vessel types. In subgroup analysis for spasm(+) vessels, diffuse spasms showed significantly lower TAG than focal spasms, while the ProxHU did not differ between the two types of spasm.

Conclusions

A relatively large percentage of coronary spasms present as diffuse type, and the TAG values significantly differed according to the morphological type of the coronary spasm.

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.

Patients with acute myocardial infarction and non-obstructive coronary arteries: safety and prognostic relevance of invasive coronary provocative tests

Aims

Functional alterations of epicardial coronary arteries or coronary microcirculation represent a frequent cause of myocardial infarction and non-obstructive coronary arteries (MINOCA). We aimed at assessing the prognostic value of intracoronary provocative tests in patients presenting with MINOCA and in which other causes of MINOCA have been excluded.

Methods and results

We prospectively evaluated patients with a diagnosis of MINOCA, excluding patients with aetiologies other than suspected coronary vasomotor abnormalities. Immediately after coronary angiography, an invasive provocative test using acetylcholine or ergonovine was performed. The incidence of death from any cause, cardiac death, and recurrence of acute coronary syndrome (ACS) was assessed at follow-up. We also assessed angina status using Seattle Angina Questionnaires (SAQ). We enrolled 80 consecutive patients [mean age 63.0 ± 10.7 years, 40 (50%) male]. Provocative test was positive in 37 (46.2%) patients without any complication. Among patients with a positive test, epicardial spasm was detected in 24 (64.9%) patients and microvascular spasm in 13 (35.1%) patients. After a median follow-up of 36.0 (range 12.0-60.0) months, patients with a positive test had a significantly higher occurrence of death from any cause [12 (32.4%) vs. 2 (4.7%); P = 0.002], cardiac death [7 (18.9%) vs. 0 (0.0%); P = 0.005], and readmission for ACS [10 (27.0%) vs. 3 (7.0%); P = 0.015] as well as a worse angina status as assessed by SAQ [Seattle score: 88.0 (33.0-100.0) vs. 100.0 (44.0-100.0); P = 0.001] when compared with patients with a negative test.

Conclusions

We demonstrate that in patients presenting with MINOCA and suspected coronary vasomotor abnormalities, a positive provocative test for spasm is safe and identifies a high-risk subset of patients.

The impact of intraday glucose variability on coronary artery spasm in patients with dysglycemia

Impaired glucose metabolism is associated with an increased risk of cardiovascular complications, and coronary artery spasm is thought to underlie the development of coronary artery disease. Intraday glucose variability (GV) accelerates oxidative stress and inflammatory cytokine release, but its impact on coronary artery spasm remains unclear. This study investigated the relationship between intraday GV and coronary artery spasm. The study included 50 patients with dysglycemia and suspected coronary spastic angina. GV was analyzed by 24-h monitoring of the blood glucose concentration using a flash glucose monitoring system. The mean amplitude of glycemic excursion (MAGE) was calculated as an index of GV. Coronary artery spasm was assessed using the intracoronary acetylcholine provocation test. Coronary spasm was defined as acetylcholine-induced total or subtotal coronary occlusion. Changes in vessel diameter in response to acetylcholine were evaluated with quantitative coronary angiography. Coronary artery spasms were observed in 21 patients (42%). MAGE was significantly higher in patients with spasms compared to those without spasms (127.5 ± 33.5 vs. 91.4 ± 37.6, p < 0.01). Regression analysis showed a positive correlation between MAGE levels and coronary diameter changes induced by acetylcholine (r = 0.47, p < 0.01). In multiple regression analysis, MAGE was independently associated with acetylcholine-induced coronary diameter change (β = 0.47, p < 0.01). Intraday GV was associated with coronary artery spasm in patients with dysglycemia.

Coronary spasm: It’s common, but it’s still unsolved

Coronary spasm is caused by a transient coronary narrowing due to the constriction of epicardial coronary artery, which leads to myocardial ischemia. More than 50 years have passed since the first recognition of coronary spasm, and many findings on coronary spasm have been reported. Coronary spasm has been considered as having pivotal roles in the cause of not only rest angina but also exertional angina, acute coronary syndrome, and heart failure. In addition, several new findings of the mechanism of coronary spasm have emerged recently. The diagnosis based mainly on coronary angiography and spasm provocation test and the mainstream treatment with a focus on a calcium-channel blocker have been established. At a glance, coronary spasm or vasospastic angina (VSA) has become a common disease. On the contrary, there are several uncertain or unsolved problems regarding coronary spasm, including the presence of medically refractory coronary spasm (intractable VSA), or an appropriate use of implantable cardioverter defibrillator in patients with cardiac arrest who have been confirmed as having coronary spasm. This editorial focused on coronary spasm, including recent topics and unsolved problems.

Clinical outcome according to spasm type of single coronary artery provoked by intracoronary ergonovine tests in patients without significant organic stenosis

BACKGROUND

This study aimed to evaluate clinical implications of single vessel coronary spasm provoked by intracoronary ergonovine provocation test in Korean population.

METHOD

A total of 1248 patients who presented with single vessel coronary artery spasm induced by intracoronary ergonovine provocation test, excluding 1712 with negative spasms, multiple and mixed coronary artery spasms and missing data among 2960 patients in the VA-KOREA (Vasospastic Angina in Korea) registry, were classified into diffuse (n=705) and focal (n=543) groups.

RESULTS

The 24-month incidences of a composite primary endpoints (cardiac death, new-onset arrhythmia, and acute coronary syndrome) were determined. Over a median follow-up of 30months, the composite primary end point occurred more frequently in the focal type patients than in the diffuse type patients (primary endpoint: adjusted hazard ratio [aHR], 1.658; 95% confidence interval [CI] 1.272 to 2.162, P<0.001). Especially, unstable angina in ACS components played a major role in this effect (hazard ratio [HR], 2.365; 95% confidence interval [CI] 1.100 to 5.087, P=0.028).

CONCLUSION

Focal type of single vessel coronary artery spasm in vasospastic angina (VSA) patients is found to be associated with worse clinical outcomes. It is thought that the effect is stemmed from unstable angina among ACS rather than the other components of primary endpoint. Therefore, focal type of single vessel coronary artery spasm in patients with VSA should be more carefully assessed and managed with appropriate medication.

Management standards for stable coronary artery disease in India

Coronary artery disease (CAD) is one of the important causes of cardiovascular morbidity and mortality globally, giving rise to more than 7 million deaths annually. An increasing burden of CAD in India is a major cause of concern with angina being the leading manifestation. Stable coronary artery disease (SCAD) is characterised by episodes of transient central chest pain (angina pectoris), often triggered by exercise, emotion or other forms of stress, generally triggered by a reversible mismatch between myocardial oxygen demand and supply resulting in myocardial ischemia or hypoxia. A stabilised, frequently asymptomatic phase following an acute coronary syndrome (ACS) is also classified as SCAD. This definition of SCAD also encompasses vasospastic and microvascular angina under the common umbrella.

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.

Coronary artery spasm: Current knowledge and residual uncertainties

Myocardial ischaemia results from a direct mismatch between oxygen supply and demand, commonly arising as a result of coronary atherosclerosis, microvascular dysfunction or acute thrombosis and luminal obstruction. However, transient ischaemia may also occur due to coronary spasm leading to acute and unexpected myocardial ischaemia without obvious visible coronary pathology. Aside from symptoms of chest pain, coronary spasm can cause infarction, LV impairment, promote life threatening arrhythmias and ultimately sudden cardiac death. While therapeutic options are available, controversies exist around diagnosis, pathology, management and prognosis. This review summarises some of the common questions in this area. In particular we explore and discuss the available evidence for the pharmacological treatment of coronary spasm, and strategies for identification and management of very high risk patients to try and reduce the incidence of sudden premature death.

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Myocardial ischaemia results from a mismatch between oxygen supply and demand.

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Spasm might lead to myocardial ischaemia without visible coronary pathology.

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Coronary spasm can cause infarction, LV impairment and sudden cardiac death.

Gender differences in sensitivity of acetylcholine and ergonovine to coronary spasm provocation test

We examined the sex difference concerning the coronary artery response between ACh and ER in this study. We already reported the difference of coronary response between acetylcholine (ACh) and ergonovine (ER). We performed both ACh and ER tests of 461 patients (male 294 patients, female 167 patients, mean age 64.4 ± 11.3 years) during 23 years. Positive coronary spasm was defined as >99 % transient luminal narrowing with usual chest pain and/or ischemic ECG changes. Firstly, ACh was administered in incremental doses of 20/50/(80) μg into the RCA and 20/50/100/(200) μg into the LCA over 20 s. Secondly, ER was administered in a total dose of 40 μg into the RCA and of 64 μg into the LCA over 2-4 min. Intracoronary injection of ACh and ER provoked spasm in 221 patients consisting of 160 male patients and 61 female patients. In female patients, the spasm provoked by ACh was almost perfect except in two patients (59 patients, 96.7 %), while ER provoked spasm in only 20 patients (32.8 %). In male patients, provoked spasm by ACh (129 patients, 80.6 %) was significantly higher than ER (97 patients, 60.6 %). As a spasm provocation test, ACh is more sensitive than ER in both sexes and especially in females. We may select two pharmacological agents by sex differences to provoke coronary artery spasm in the cardiac catheterization laboratory in the future.

Safety and optimal protocol of provocation test for diagnosis of multivessel coronary spasm

We examined the safety of acetylcholine (ACh) and ergonovine (ER) tests retrospectively and investigated the optimal protocol of provocation test for diagnosis of multivessel coronary spasm. We performed 1546 ACh tests and 1114 ER tests during 23 years. ACh was injected in incremental doses of 20/50/80 μg into the right coronary artery (RCA) and of 20/50/100/200 μg into the left coronary artery (LCA) over 20 s. ER was administered in total doses of 40 μg into the RCA and of 64 μg into the LCA over 2-4 min. When a coronary spasm was induced and did not resolve spontaneously within 3 min after the completion of ACh/ER injection, or when hemodynamic instability due to coronary spasms occurred, 2.5-5.0 mg of nitrate was administered into the responsible vessel. To relive provoked spasm, it is necessary to administer nitrate in 31 cases by ACh and in 76 cases by ER (2.0 vs. 6.8 %, p < 0.01) before another vessel attempts. Multivessel spasms were often observed in LCA testing than in RCA testing on both agents [ACh: 78.6 % (11/14) vs. 11.8 % (2/17), p < 0.001, ER: 37.8 % (14/37) vs. 20.5 % (8/39), ns]. Even after the administration of nitrates, positive coronary spasm was obtained in 21.1 % by ACh and 52.9 % by ER tests on another coronary artery. No irreversible complications were recognized on both tests. We should firstly perform spasm provocation tests in the LCA and we may be able to diagnose another vessel spasm by performing the complete spasm provocation tests after the administration of nitrates to relieve provoked spasm in the first attempt.

Spasm provocation tests performed under medical therapy: a new approach for treating patients with refractory coronary spastic angina on emergency admission

Objective There are no objective methods for evaluating the severity of vasospasms in patients with refractory coronary spastic angina (R-CSA) under adequate medical therapy. We examined whether spasm provocation tests performed under adequate medication are useful for evaluating the severity of disease in R-CSA patients on emergency admission. Methods and Results We performed spasm provocation tests before and after the administration of medical therapy in eight R-CSA patients, including one ventricular fibrillation survivor (VF-S) and seven patients with unstable angina (UAP) on emergency readmission. We also performed these tests only after medical therapy on urgent admission in four R-CSA patients, including two patients with UAP, one patient with VF-S and one patient with acute coronary syndrome. All 12 R-CSA patients had been medicated with ≥ 2 vasodilator drugs. Positive coronary spasms were defined as >99% transient narrowing. The coronary artery spasms disappeared in three patients under medication, and mitigation of vasospasticity was observed in three patients. In these six cases we continued the same medications. Meanwhile in two patients, we recommended a consultation for psychosomatic medicine. In contrast, the remaining six R-CSA patients exhibited higher levels of vasospasticity, irrespective of the administration of aggressive medical therapy, in which the doses of vasoactive drugs were increased in order to suppress coronary artery spasms. Conclusion In some R-CSA patients on emergency admission, performing spasm provocation tests under medical therapy is useful for determining the subsequent treatment strategy. Therefore, this test may become a new tool in the treatment of R-CSA.

Corticosteroid therapy was effective in controlling refractory coronary vasospasms complicated by hypereosinophilia

A 48-year-old man suffered from uncontrollable coronary vasospasms, even when taking the maximum dose of vasodilators. The patient had a history of hypereosinophilia, and as the eosinophilia worsened, more frequent and intense coronary spastic angina (CSA) attacks occurred. He was treated with 20 mg/day of oral prednisolone, and the chest symptoms of CSA completely resolved thereafter. We encountered a refractory CSA patient with an allergic predisposition for which the oral administration of corticosteroids was markedly effective. Although the priority of corticosteroid therapy is not clinically high in patients with CSA, it can be effective especially in patients with an allergic background.

Coronary vasomotor response to intracoronary acetylcholine injection, clinical features, and long-term prognosis in 873 consecutive patients with coronary spasm: analysis of a single-center study over 20 years

BACKGROUND

The aim of this study was to elucidate the correlation between angiographic coronary vasomotor responses to intracoronary acetylcholine (ACh) injection, clinical features, and long-term prognosis in patients with vasospastic angina (VSA).

METHODS AND RESULTS

This is a retrospective, observational, single-center study of 1877 consecutive patients who underwent ACh-provocation test between January 1991 and December 2010. ACh-provoked coronary spasm was observed in 873 of 1637 patients included in the present analysis. ACh-positive patients were more likely to be older male smokers with dyslipidemia, to have a family history of ischemic heart disease, and to have a comorbidity of coronary epicardial stenosis than were ACh-negative patients. ACh-positive patients were divided into 2 groups: those with focal (total or subtotal obstruction, n=511) and those with diffuse (severe diffuse vasoconstriction, n=362) spasm patterns. Multivariable logistic regression analysis identified female sex and low comorbidity of coronary epicardial stenosis to correlate with the ACh-provoked diffuse spasm pattern in patients with VSA. Kaplan-Meier survival curve indicated better 5-year survival rates free from major adverse cardiovascular events in patients with diffuse spasm pattern compared with those with focal spasm pattern (P=0.019). Multivariable Cox hazard regression analysis identified diffuse spasm pattern as a negative predictor of major adverse cardiovascular events in patients with VSA.

CONCLUSIONS

ACh-induced diffuse coronary spasm was frequently observed in female VSA patients free of severe coronary epicardial stenosis and was associated with better prognosis than focal spasm. These results suggest the need to identify the ACh-provoked coronary spasm subtypes in patients with VSA.

Clinical implications of provocation tests for coronary artery spasm: safety, arrhythmic complications, and prognostic impact: multicentre registry study of the Japanese Coronary Spasm Association

AIMS

Provocation tests of coronary artery spasm are useful for the diagnosis of vasospastic angina (VSA). However, these tests are thought to have a potential risk of arrhythmic complications, including ventricular tachycardia (VT), ventricular fibrillation (VF), and brady-arrhythmias. We aimed to elucidate the safety and the clinical implications of the spasm provocation tests in the nationwide multicentre registry study by the Japanese Coronary Spasm Association.

METHODS AND RESULTS

A total of 1244 VSA patients (M/F, 938/306; median 66 years) who underwent the spasm provocation tests were enrolled from 47 institutes. The primary endpoint was defined as major adverse cardiac events (MACEs). The provocation tests were performed with either acetylcholine (ACh, 57%) or ergonovine (40%). During the provocation tests, VT/VF and brady-arrhythmias developed at a rate of 3.2 and 2.7%, respectively. Overall incidence of arrhythmic complications was 6.8%, a comparable incidence of those during spontaneous angina attack (7.0%). Multivariable logistic regression analysis demonstrated that diffuse right coronary artery spasm (P < 0.01) and the use of ACh (P < 0.05) had a significant correlation with provocation-related VT/VF. During the median follow-up of 32 months, 69 patients (5.5%) reached the primary endpoint. The multivariable Cox proportional hazard model revealed that mixed (focal plus diffuse) type multivessel spasm had an important association with MACEs (adjusted hazard ratio, 2.84; 95% confidence interval, 1.34-6.03; P < 0.01), whereas provocation-related arrhythmias did not.

CONCLUSION

The spasm provocation tests have an acceptable level of safety and the evaluation of spasm type may provide useful information for the risk prediction of VSA patients.

[Variant angina: what to think in 2011?]

Spastic angina is considered rare but its prevalence is probably underestimated especially in case of atherosclerotic coronary lesions. Its diagnosis remains important due to its poor prognosis and therapeutic characteristics. We report three clinical cases illustrating two different clinical presentations and the problem of diagnosis of spastic angina. We performed a review of the literature essentially concerning commonly used diagnosis means and especially provocative testing for coronary spasm. This test needs to be adapted to the evolution of techniques and uses of coronary angiography in 2011, particularly the wide spread use of radial approach. Therefore new recommendations are needed, specifying the terms of provocative testing and establishing clear diagnosis criteria including clinical, electrocardiographic and angiographic data. Such guidelines would probably help to better diagnose and treat these patients in our practice.

Disruption of coronary vasomotor function: the coronary spasm syndrome

Abnormal coronary vasoconstriction, or coronary spasm, can be the result of several factors, including local and neuroendocrine aberrations. It can manifest clinically as a coronary syndrome and plays an important role in the genesis of myocardial ischemia. Over the past half century, coronary angiography allowed the in vivo demonstration of spasm in patients who fit the initial clinical description of the condition as reported by Prinzmetal et al. Several clinical, basic, and more recently, genetic studies have provided insight into the pathogenesis, manifestations, and therapy of this condition. It is not uncommonly encountered in patients with coronary syndromes and absence of clearly pathologic lesions on angiography. Provocation tests utilizing pharmacologic and nonpharmacologic stimuli combined with imaging (echocardiography or coronary angiography) can help make the correct diagnosis. The use of calcium channel blockers and long-acting nitrates is currently considered standard of care and the overall prognosis appears to be good. The recent discovery of genetic abnormalities predisposing to abnormal spasm of the coronaries has stimulated interest in the development of targeted therapies for the management of this condition.

Recent advances in the management of chronic stable angina I: approach to the patient, diagnosis, pathophysiology, risk stratification, and gender disparities

The potential importance of both prevention and personal responsibility in controlling heart disease, the leading cause of death in the USA and elsewhere, has attracted renewed attention. Coronary artery disease is preventable, using relatively simple and inexpensive lifestyle changes. The inexorable rise in the prevalence of obesity, diabetes, dyslipidemia, and hypertension, often in the risk cluster known as the metabolic syndrome, drives the ever-increasing incidence of heart disease. Population-wide improvements in personal health habits appear to be a fundamental, evidence based public health measure, yet numerous barriers prevent implementation. A common symptom in patients with coronary artery disease, classical angina refers to the typical chest pressure or discomfort that results when myocardial oxygen demand rises and coronary blood flow is reduced by fixed, atherosclerotic, obstructive lesions. Different forms of angina and diagnosis, with a short description of the significance of pain and silent ischemia, are discussed in this review. The well accepted concept of myocardial oxygen imbalance in the genesis of angina is presented with new data about clinical pathology of stable angina and acute coronary syndromes. The roles of stress electrocardiography and stress myocardial perfusion scintigraphic imaging are reviewed, along with the information these tests provide about risk and prognosis. Finally, the current status of gender disparities in heart disease is summarized. Enhanced risk stratification and identification of patients in whom procedures will meaningfully change management is an ongoing quest. Current guidelines emphasize efficient triage of patients with suspected coronary artery disease. Many experts believe the predictive value of current decision protocols for coronary artery disease still needs improvement in order to optimize outcomes, yet avoid unnecessary coronary angiograms and radiation exposure. Coronary angiography remains the gold standard in the diagnosis of coronary artery obstructive disease. Part II of this two part series will address anti-ischemic therapies, new agents, cardiovascular risk reduction, options to treat refractory angina, and revascularization.

Clinical and angiographic characteristics of acute myocardial infarction caused by vasospastic angina without organic coronary heart disease

BACKGROUND

Vasospastic angina (VA) can occasionally cause acute myocardial infarction (AMI).

METHODS AND RESULTS

From January 2003 to June 2005, coronary spastic angina was diagnosed in 292 patients by performing spasm provocation tests. Among the 292 patients, 21 (7.2% of all the VA patients) had an AMI. There were 20 patients who initially visited the emergency room for AMI without suffering prior VA. One patient with a history of VA had an AMI when he discontinued his medication. Among the 21 VA patients with AMI, 14 had experienced severe emotional stress before they visited the emergency room. The spasm provocation test showed that the VA patients with AMI had more multivessel and diffuse spasm than the VA patients without AMI (p<0.001).

CONCLUSION

Clinically, the VA patients with AMI usually had their first symptom of VA as the severe chest pain of AMI. Two-thirds of the VA patients with AMI had experienced emotional stress before their AMI. Angiographically, the spasm provocation test for VA patients with AMI showed more multivessel and diffuse spasm than in VA patients without AMI.

The endothelial nitric oxide synthase gene -786T/C polymorphism is a predictive factor for reattacks of coronary spasm

OBJECTIVE

We previously found a -786T/C polymorphism in the 5'-flanking region of the endothelial nitric oxide synthase (eNOS) gene and reported that this polymorphism is strongly associated with coronary spasm. In this study, we examined whether the polymorphism is a prognostic marker in coronary spasm patients.

METHODS AND RESULTS

We examined the clinical courses of 201 consecutive patients with coronary spasm who were admitted to our institution: 146 patients with the -786T/T genotype; 50 patients with the -786C/T genotype; and five patients with the -786C/C genotype. The mean follow-up period was 76+/-60 months. All the patients took calcium channel blockers and/or nitrate during the follow-up period. In this study, no patients died due to a cardiac event. About 25 patients were readmitted owing to cardiovascular disease. Out of these 25 patients, 23 patients were readmitted owing to a reattack of coronary spasm. The -786C allele was significantly associated with readmission due to coronary spasm (P=0.0072, odds ratio: 3.37 in the dominant effect). Kaplan-Meier analysis revealed that the occurrence of readmission was significantly higher in the patients with the -786C allele than in the patients without the -786C allele (P=0.0079). Further, multiple logistic regression analysis revealed that the -786T/C polymorphism was an independent predictor for readmission due to reattack of coronary spasm (P=0.006; relative risk=3.590).

CONCLUSIONS

The eNOS -786C allele is an independent risk factor for readmission due to a recurrent attack of coronary spasm in patients with coronary spasm, even if the patients have taken calcium channel blockers and/or nitrate.

Comparison of Clinical Characteristics and Prognosis in Taiwanese Patients With Coronary Vasospastic Angina Pectoris Without Significant Fixed Coronary Artery Disease Versus Patients With Significant Fixed Coronary Artery Disease and Either Stable Angina Pectoris or Acute Coronary Syndromes

BACKGROUND

Limited information is available comparing the clinical characteristics and prognosis for patients with coronary vasospastic angina in the absence of hemodynamically significant coronary artery disease (CAD) (defined as >50% stenosis) versus patients with significant fixed CAD presenting with either stable angina pectoris (SAP) or acute coronary syndromes (ACS).

METHODS

Patients who underwent cardiac catheterization for suspected ischemic heart disease between August 1999 and February 2003 were followed clinically. For patients without hemodynamically significant CAD, a provocation test for coronary vasospasm was undertaken using a step-wise dose of intracoronary ergonovine administration.

RESULTS

A total of 1134 patients were enrolled in the final analysis and stratified into 4 diagnostically distinct groups: control group (n = 239; mild CAD without coronary vasospasm); vasospasm group (n = 284; coronary vasospastic angina pectoris without hemodynamically significant CAD); SAP group (n = 110; hemodynamically significant CAD with SAP); ACS group (n = 501; hemodynamically significant CAD with ACS). Comparison of these 4 groups revealed that the ACS patients were more likely to be male, current smokers, and have hypercholesterolemia. In addition, this group had a significantly higher incidence of typical angina pectoris, 3-vessel CAD, and lower left ventricular ejection fraction. Between-group comparison revealed that vasospasm patients had a significantly higher incidence of early morning angina pectoris. Multivariate analysis showed that current smoking was the most independent risk factor associated with the diagnosis of coronary vasospastic angina pectoris in patients without hemodynamically significant CAD. During a median follow-up period of 49 months, recurrent angina pectoris was noted in patients from the control (n = 6; 3%), SAP (n = 9; 8%), vasospasm (n = 30, 11%), and ACS groups (n = 92; 18%); with nonfatal myocardial infarction identified during follow-up in the SAP (n = 5; 5%), vasospasm (n = 3; 1%), and ACS groups (n = 37; 7%). In addition, 29 and 3 cardiac deaths occurred in the ACS and SAP groups, respectively, whereas there were no such mortalities in the control and vasospasm groups.

CONCLUSIONS

Early morning angina pectoris and cigarette smoking were the most common clinical characteristics in patients with coronary vasospasm. These patients had an excellent prognosis despite the possibility of recurrences of vasospastic angina pectoris.

Effectiveness of intravenous administration of nicorandil in a patient with variant angina refractory to continuous intravenous nitroglycerin

Variant angina usually responds to conventional treatment with nitrates and calcium antagonists. However, severe variant angina refractory to intensive anti-anginal treatment can be catastrophic because prolonged occlusion of a major coronary artery can result in myocardial infarction, severe cardiac arrhythmia, and sudden death. We report a patient with active variant angina which was refractory to conventional treatment including sublingual nitroglycerin and intravenous nitroglycerin administration. Only intravenous administration of nicorandil was consistently effective in eliminating chest pain of the patient.

Airway hyperresponsiveness in patients with coronary spastic angina: relationship between coronary spasticity and airway responsiveness

BACKGROUND

Several reports have suggested a possible link between bronchial asthma and coronary spasm, but the possibility of a relationship in coronary spastic angina (CSA) has not been clarified.

METHODS AND RESULTS

Airway responsiveness to methacholine and coronary spasticity to acetylcholine were examined in 42 patients with CSA and 36 patients with chest pain syndrome (CP). Furthermore, 18 control subjects were examined and their airway responsiveness compared with that of the CSA and CP patients. The incidence of airway hyperresponsiveness was significantly higher in the CSA group (74%) than in the CP (19%) and control (17%) groups (p<0.0001). The geometric mean of the log minimum dose (Dmin), defined as the cumulative dose at the point at which respiratory conductance began to decrease, was significantly lower in the CSA group (0.75 log units) than in the CP (1.20 log units) and control (1.38 log units) groups (p=0.004).

CONCLUSION

These results demonstrate that acetylcholine-induced coronary spasticity is significantly related to methacholine-induced airway responsiveness in patients with CSA. A generalized hyperresponsiveness of the vascular and nonvascular smooth muscles, including that through cholinergic mechanisms, may exist in patients with CSA.

A long-acting calcium antagonist over one year did not improve BMIPP myocardial scintigraphic imagings in patients with pure coronary spastic angina

BACKGROUND

Calcium antagonists (Ca) have been effective in reducing angina attacks in patients with variant angina. However, there are no reports regarding the effectiveness of Ca on myocardial fatty acid metabolic images in patients with pure coronary spastic angina (CSA).

OBJECTIVES

This study sought to examine the correlation between myocardial fatty acid metabolic images and the medical treatment of Ca in patients with pure CSA.

METHODS AND RESULTS

This study included 35 consecutive patients (28 men, mean age of 66 +/- 10 years) with angiographically confirmed coronary spasm and no fixed stenosis. Long-acting Ca was administered to all 35 patients. Isosorbide dinitrate /nicorandil/another Ca/beta-bloker were administered when chest pain was not controlled. Using an iodinated fatty acid analogue, 15-(p-[iodine-123]iodophenyl)-3-(R,S)methylpentadecanoic acid (BMIPP), myocardial scintigraphies with intravenous adenosine triphosphate infusion were performed before cardiac catheterization and 12 mo after medical therapy. According to the medical control states, these 35 patients were classified into 3 groups; response (disappearance of angina attacks, 12 pts, 60 +/- 11 years), partial response (angina attacks < 4/mo, 12 pts, 67 +/- 10 years), and no response to therapy (angina attacks > or = 4/mo, 11 pts, 71 +/- 6 years). Reduced BMIPP uptake was observed in 24 (69%) of 35 patients before the treatment. Reduced BMIPP uptake was also found in 18 patients (51%) after 12 mo. Normal BMIPP uptake after 12 mo therapy was observed in about half (response: 42%, partial response: 58%, no response: 45%) of patients among the 3 groups. There was no difference regarding the value of washout rate (WOR) (response; 10 +/- 7 (before), 14 +/- 8% (12 mo)), partial response; 11 +/- 7, 10 +/- 5%, no response; 13 +/- 9, 14 +/- 8%) among the 3 groups. The defect scores of BMIPP in the three groups were not different during at least one year medical therapy. No difference regarding the distribution of other medical therapies (angiotensin converting enzyme inhibitors/angiotensin receptor blockers/beta-blockers/statins) was found. The administration of Ca and isosorbide dinitrate/nicorandil and 2 Ca was significantly higher in the poor than in the good control patients.

CONCLUSIONS

Long-acting Ca over one year did not improve myocardial fatty acid metabolic images in patients with pure CSA. This may be related to silent ischemia.

The mystery of coronary artery spasm

Coronary artery spasm is an important cause of chest pain and myocardial ischaemia. It can be defined as an exaggerated contractile response of epicardial coronary artery smooth muscle to various stimuli but the underlying mechanism is not well understood. Recent studies have shown that the loss of endothelial vasodilatory function in conjunction with an increase in vascular smooth muscle constrictor sensitivity to calcium are the likely predisposing conditions for coronary spasm. This review highlights current understanding of the pathophysiology, predisposing factors, diagnostic and therapeutic approaches for coronary spasm.

Clinical impact of selective spasm provocation tests: comparisons between acetylcholine and ergonovine in 1508 examinations

BACKGROUND

There are few reports regarding the concordance of coronary arterial response between acetylcholine (ACh) and ergonovine (ER) spasm provocation tests.

OBJECTIVES

We attempted to perform selective spasm provocation tests to examine the incidence of provoked spasm in patients who had undergone first coronary angiography as much as possible and we compared the coronary arterial response and clinical usefulness between selective intracoronary injection of ACh and intracoronary administration of ER.

METHODS

We performed 1508 selective spasm provocation tests, consisting of 873 ACh tests and 635 ER tests, from 1991 to 2002. We examined the frequency of provoked spasms of each agent retrospectively. ACh was injected in incremental doses of 20, 50 and 80 microg into the right coronary artery and 20, 50 and 100 microg into the left coronary artery. ER was administered as 10 microg/min over 4 min for a maximal dose of 40 microg in the right coronary artery and as 16 microg/min over 4 min for a total dose of 64 microg in the left coronary artery. Coronary spasm was defined as transient >99% luminal narrowing.

RESULTS

Intracoronary ACh provoked spasms in 36.0% of patients and intracoronary ER induced spasms in 29.8% of patients. In patients with ischemic heart disease, the incidence of provoked spasms was not different between ACh tests (50.9%) and ER tests (43.8%). In contrast, the frequency of provoked spasms with ACh tests was significantly higher than that with ER tests (11.0% compared with 6.4%, P<0.05) in patients without ischemic heart disease. Moreover, ACh provoked more spasms in patients without fixed stenosis than ER (36.2% compared with 25.5%, P<0.01) and multiple spasms were frequently observed when performing ACh tests (40.0% compared with 27.0%, P<0.01). Major complications were observed in 1.4% of patients with ACh tests and in 0.2% of patients with ER tests. The need for intracoronary administration of isosorbide dinitrate to relieve coronary spasms during ER testing before performing another coronary artery test was more frequently observed in ACh tests (5.04% compared with 1.49%, P<0.01). However, no serious irreversible complications, such as death or acute myocardial infarction, were observed in this study. There was a significant difference in sex, history of smoking and hyperlipidemia between patients with and without spasms for both tests, whereas no difference in age or hypertension was observed in either test.

CONCLUSION

Thus, both selective ACh and ER tests were useful as spasm provocation tests.

Is there a role for provocation testing to diagnose coronary artery spasm?

Spontaneous coronary artery spasm is an important cause of morbidity both in patients with coronary artery disease and in those with variant angina. A number of pharmacological agents have been identified which can provoke coronary artery spasm in susceptible patients. The role of provocation testing in the clinical diagnosis of coronary spasm is controversial. This is reflected by variations in the clinical use of provocation testing between specialist cardiac centres. Provocation testing appears to be a sensitive method of identifying patients with variant angina and active disease but such patients can often be diagnosed clinically. The specificity is less clear. There is little evidence that altering patient therapy on the basis of a positive test modifies prognosis. There may be a role for provocation testing in rare patients with refractory disease to identify a target site for coronary stenting. A more widespread use of these tests in patients with undiagnosed chest pain syndromes would not currently be recommended.

Thoracic myelitis as a possible cause of myocardial infarction

During the course of an inflammatory process in the thoracic part of the spinal cord, a previously healthy male suffered two myocardial infarctions in separate coronary territories. A coronary angiogram revealed only minor wall changes in one coronary artery. We hypothesize that the myocardial infarctions may have been caused by vasospastic reactions secondary to his spinal cord pathology, and present the case report and a review of the literature.

The interaction of coronary tone and cardiac fibrosis

Regulation of coronary vascular tone is critical for proper perfusion and function of the myocardium. Many disease processes result in compromised regulation of coronary vascular tone and impaired myocardial perfusion. A common result of coronary vascular dysfunction is the development of areas of replacement fibrosis within the myocardium and surrounding the vasculature. Both intravascular processes, such as coronary atherosclerosis and endothelial dysfunction, and extravascular processes, including compromised myocardial metabolism, hormone excesses, and altered local signaling, may result in coronary vascular dysregulation. Coronary occlusion events, in turn, lead to myocardial damage and the activation of inflammatory cells and fibroblasts. The role of fibroblasts in regulating myocardial fibrosis and the contribution of myofibroblasts, cells that have limited contractile potential while retaining many of the extracellular matrix regulating processes of the fibroblast, may also contribute to the development of myocardial disease. In this review we examine the recent literature on myocardial fibrosis and myofibroblast activity, highlighting the effects of several classes of cardiovascular agents on the remodeling process.

Frequency of provoked coronary spasms in patients undergoing coronary arteriography using a spasm provocation test via intracoronary administration of ergonovine

There are no data concerning the incidence of provoked coronary arterial spasms via intracoronary administration of ergonovine (ER). This study sought to establish the incidence of spasms due to intracoronary injection of ER in Japanese patients who underwent coronary angiography. The subjects were 596 consecutive patients (369 men, mean age 64.2 +/- 10.3 years) who were studied with a selective ER test. ER was administered in total doses of 40 microg into the right coronary artery and 64 microg into the left coronary artery. A positive spasm was defined as a total or subtotal occlusion. Coronary vasospasms were determined in 173 patients (29.0%). Spasms occurred often in patients with ischemic heart disease (43.3%); during effort and rest in patients with angina (46.3%), exertional angina (27.7%), recent myocardial infarction (36.7%), healed myocardial infarction (34.1%), and especially in patients with rest angina (55.5%), but were relatively uncommon in patients with nonischemic heart disease (3.7%). The incidence of provoked coronary spasms in this study was 2.2-2.6 times higher than in previous reports with intravenous ER administration. More spasms were superimposed on significant atherosclerotic lesions than on nonfixed atherosclerotic lesions (42.8% vs 24.0%, p < 0.01). No serious or irreversible complications were observed in this study. In conclusion, intracoronary administration of ER was a safe and reliable test. Compared with Caucasian patients, in Japanese patients, coronary arterial spasms occurred 2-3 times more frequently with various cardiac disorders.

Coronary vasospasm and the regulation of coronary blood flow

Under physiologic conditions, epicardial arteries contribute minimally to coronary vascular resistance. However, in the presence of endothelial dysfunction, stimuli that normally produce vasodilation may instead cause constriction. Examples include neural release of acetylcholine or norepinephrine, platelet activation and production of serotonin and thrombin, and release of local factors such as bradykinin. This shift from a primary endothelial-mediated vasodilator influence to one of endothelial dysfunction and unchecked vasoconstriction is precisely the milieu in which coronary vasospasm is observed. This condition, which typically occurs during periods of relatively sedentary activity, is associated with focal and transient obstruction of an epicardial arterial segment resulting in characteristic echocardiographic changes and symptoms of myocardial ischemia. This review highlights the current understanding of mechanisms regulating the coronary circulation during health and examines the pathophysiologic changes that occur with coronary spasm. Genetic and other predisposing conditions are addressed, as well as novel therapies based on recent mechanistic insights of the coronary contractile dysfunction associated with coronary spasm.

Did the Widespread Use of Long-Acting Calcium Antagonists Decrease the Occurrence of Variant Angina?

BACKGROUND

We have not often encountered variant angina (VA) since the use of long-acting calcium antagonists (L-CAs) became widespread.

OBJECTIVES

This study examined the frequency of VA retrospectively.

METHODS

and results: We diagnosed angiographically confirmed coronary spastic angina (CSA) in 349 consecutive patients using selective spasm provocation tests from January 1991 to December 2002. During this period, 3,148 diagnostic cardiac catheterizations and 1,515 selective spasm provocation tests were performed. Seventy-four of these 349 patients (21.2%) had VA. Coronary spasms were defined as transient luminal narrowings of > 99%, and VA was defined as an ST elevation during spontaneous attacks or noninvasive stress tests. We classified the 12 years of the study into four periods of 3 years each. No tendency to decrease for the ratio of the number of patients with CSA and the number of selective spasm provocation tests was observed among the four time periods (18%, 24%, 32%, and 23%, respectively). However, the number of patients with VA (28, 33, 9, and 4) and the VA/CSA ratio (32%, 28%, 14%, and 5%, respectively) in the four group significantly decreased. The frequency of administration of calcium antagonists (CAs) before hospital admission (49% vs 33%, respectively; p < 0.05) was significantly higher in the last time period (from 2000 to 2002) than in the first period (from 1991 to 1993). L-CAs were administered in > 90% of CSA patients who had been medicated with CAs before hospital admission in the last period (from 2000 to 2002), while L-CAs were administered in only 20% in the former period (from 1991 to 1993). The administration of statins and angiotensin-converting enzyme inhibitors/angiotensin receptor blockers before hospital admission gradually increased according to the period passed, but not significantly.

CONCLUSION

The frequency of VA has decreased in Japan, possibly due to the widespread use of therapy with L-CAs.

Coronary flow reserve in patients with vasospastic angina: correlation between coronary flow reserve and age or duration of angina

OBJECTIVES

This study sought to assess the coronary flow reserve (CFR) in patients with pure vasospastic angina (VSA).

METHODS AND RESULTS

The phasic flow velocities of both spasm-positive and spasm-negative coronary arteries of the left anterior descending artery (LAD) were recorded at rest and during hyperaemia (50 microg of adenosine triphosphate infusion intracoronary) using a 0.014 inch, 15 MHz Doppler guide wire in 42 patients with pure VSA and acetylcholine (ACh)-induced coronary artery spasms (20-100 microg), and 23 controls with normal coronary arteries without ACh-induced vasospasm. These 42 patients had 16 vessels with focal spasms (>99%), 17 vessels with diffuse spasms (>90%) in the LAD, and nine vessels with ACh-induced spasms in the right coronary artery, but not the LAD. Coronary flow reserve was obtained from the ratio of the hyperaemic/baseline time-averaged peak velocity. Coronary flow reserve did not differ between patients with VSA and the controls (2.9+/-0.8 versus 3.2+/-0.7, NS). Moreover, CFR did not differ among the four cases (focal: 2.8+/-0.7; diffuse: 3.0+/-0.9; non spasm: 2.9+/-0.7 versus controls: 3.2+/-0.7, respectively, NS). Coronary flow reserve in vessels with proximal spasms was significantly higher than that in vessels with mid or distal spasms (3.4+/-0.8 versus 2.6+/-0.6, 2.6+/-0.9, p<0.05). The only significant correlation was between CFR and age (p=0.0275) or the duration of angina before admission (p=0.0405).

CONCLUSIONS

There was no difference in CFR in patients with ACh-induced spasms between the spasm-positive and spasm-negative vessels. Moreover, CFR was maintained normally in vessels with diffuse spasms, as in those with focal spasms. The most important determinant factors for CFR in patients with VSA were age and the duration of angina before admission.