Comparison of coronary flow reserve between focal and diffuse vasoconstriction induced by ergonovine in patients with vasospastic angina

Noninvasive evaluation of dynamic microvascular dysfunction in ischemia and no obstructive coronary artery disease patients with suspected vasospasm

INTRODUCTION

In patients with ischemia and no obstructive coronary artery disease (INOCA), a dynamic coronary microvascular dysfunction (CMD) is frequent but difficult to capture by noninvasive means.The aim of our study was to assess dynamic CMD in INOCA patients with stress echocardiography after vasoconstrictive and vasodilator stimuli.

METHODS

In this prospective single-center study, we have enrolled 40 INOCA patients (age 56.3 ± 13 years, 32 women). All participants underwent stress echocardiography with hyperventilation (HYP), followed by supine bicycle exercise (HYP+EXE) and adenosine (ADO). Stress echocardiography included an assessment of regional wall motion abnormality (RWMA) and coronary flow velocity (CFV) in the distal left anterior descending (LAD) coronary artery.

RESULTS

HYP induced a 30% increase in rate pressure product (rest = 10 244 ± 2353 vs. HYP = 13 214 ± 3266 mmHg x bpm, P  < 0.001) accompanied by a paradoxical reduction in CFV (HYP< rest) in 21 patients (52%). HYP alone was less effective than HYP+EXE in inducing anginal pain (6/40, 15% vs. 10/40, 25%, P  = 0.046), ST segment changes (6/40, 15% vs. 24/40, 60%, P  < 0.001), and RWMA (6/40, 15% vs. 13/40, 32.5%, P  = 0.008). ADO-induced vasodilation was preserved (≥2.0) in all patients.

CONCLUSION

In patients with INOCA, a coronary vasoconstriction after HYP is common, in absence of structural CMD detectable with ADO. HYP+EXE test represents a more powerful ischemia inducer than HYP alone. Stress echocardiography with LAD-CFV may allow the noninvasive assessment of dynamic and structural coronary microcirculation during stress.

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.

Positive Stress Electrocardiography in Patients With Non-obstructive Coronary Disease

Introduction The episodes of myocardial ischemia in patients with non-obstructive coronary disease are extremely variable in provoking factors and presentation. Purpose We investigated the significance of coronary blood flow velocity and epicardial diameter as correlates of a positive electrocardiographic exercise stress test (ExECG) in hospitalized patients with unstable angina and non-obstructive coronary artery disease. Methods The study was a single-center cohort retrospective. ExECG was performed and analyzed in a group of 79 patients with non-obstructive coronary disease (coronary stenoses < 50%). Thirty-one percent of the patients (n=25) were diagnosed with slow coronary flow phenomenon, SCFP; 40.5% (n=32) - patients with hypertensive disease, left ventricular hypertrophy (LVH), and slow epicardial flow; 27.8% (n=22) with hypertension, left ventricular hypertrophy and normal coronary flow. The patients were hospitalized in University Hospital "Alexandrovska," Sofia in the period 2006-2008. Results The frequency of positive ExECG is increased as a trend was associated with smaller epicardial diameters and pronounced delay in epicardial coronary flow. In the subgroup with SCFP, the risk for a positive ExECG test was determined by slower coronary flow (36.5±7.7 frames vs. 30.3±4.4 frames, p=0.044) and borderline significant by epicardial lumen diameters (3.3±0.8 mm vs. 4.1±1.0 mm, p=0.051) and greater myocardial mass (92.8±12.6 g/m² vs. 82.9±8.6 g/m², p=0.054). In cases of left ventricular hypertrophy, which included both patients with the normal and slow epicardial flow, there were no statistically significant correlates of an abnormal exercise stress ECG test. Conclusions In patients with non-obstructive coronary atherosclerosis and predominantly slow epicardial coronary flow, the provoking of ischemia at an electrocardiographic exercise stress test is associated with the lower epicardial flow velocity at rest and with the smaller epicardial diameter. In SCFP, the risk for an abnormal stress test is determined by slower coronary flow, smaller epicardial lumen diameter, and greater myocardial mass. The presence and size of the plaque burden are not associated with a greater risk of a positive ExECG in these 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.

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.

Coronary Microvascular Vasodilatory Function: Related Clinical Features and Differences According to the Different Coronary Arteries and Types of Coronary Spasm

Background: In the clinical setting; the microvascular vasodilatory function test (MVFT) with a pressure wire has been used in ischaemia patients with non-obstructive coronary arteries (INOCA), including vasospastic angina (VSA) and microvascular angina (MVA). The exact factors that affect the microvascular vasodilatory function (MVF) in such patients are still unknown. We aimed to identify the factors, including clinical parameters and lesion characteristics, affecting the MVF in such patients. Methods: A total of 53 patients who underwent coronary angiography, spasm provocation tests (SPTs) and MVFTs were enrolled. In the MVFT, the coronary flow reserve (CFR) and index of microcirculatory resistance (IMR) were measured. Of the 53 patients, MVFT data in the left anterior descending coronary artery (LAD) were obtained from 49 patients, and the clinical parameters were checked in all of them. Based on the results of the SPT, coronary spasms were divided into focal spasm, diffuse spasm, and microvascular spasm (MVS). To assess the lesion characteristics influencing MVF, MVFT data were compared according to the types of coronary spasm and coronary vessels in 73 vessels of the 53 patients. Results: In 49 patients who underwent the MVFT in the LAD, the IMR was higher in active smokers (n = 7) than in former smokers (n = 15) and never smokers (n = 27, p < 0.01). In the 73 coronary arteries in this study, the type of coronary spasm did not correlate with the CFR or IMR, whereas a higher IMR were more frequently observed in cases of focal spasm than in cases of diffuse spasm (p = 0.03). In addition, the IMR was higher in the right coronary artery (RCA) than in the LAD (p = 0.02). Conclusion: These results indicate that the smoking status affected the MVF in patients with INOCA, suggesting the possibility of improvement in the MVF by smoking cessation in such patients. In addition, in the assessment of MVF, it may be important to take into account which coronary artery or types of coronary spasm are being evaluated.

[Methergin pour le diagnostic de l'angor spastique : voie intraveineuse ou intracoronaire ?]

BACKGROUND

Vasospastic angina is an infrequent underlying cause of angina and is under-diagnosed. Ergonovine provocation tests can be performed via intravenous or intracoronary injections. Although the safety profile of intracoronary injection has been well documented, no study has yet compared the intracoronary and intravenous injections regarding the positivity rate of the test.

AIMS

This study sought to compare the positivity rate of intravenous versus intracoronary injection of ergonovine in the diagnosis of vasospastic angina.

METHODS

Between January 2010 and February 2018, 427 patients with suspected vasospastic angina underwent an ergonovine provocation test in 2 tertiary hospitals in France and were retrospectively included in this study. Injection was performed via the intravenous or the intracoronary route. The primary endpoint was the positivity rate of the test. Propensity score matching was used to account for confounding factors.

RESULTS

427 patients were included in the study. Mean age was 60.3 (+/- 12.4) years. There were 247 (58%) females and 97 (23%) smokers. The intracoronary route was used in 199 (47%) patients. The indication for the test was acute coronary syndrome for 121 (28%). No rhythmic complications or deaths were reported. After propensity-matching, the baseline characteristics of the 2 groups (148 patients in each) were comparable. The positivity rate was 24% in the intracoronary group and 9% in the intravenous group (OR [95%CI]: 3.2 [1.6, 6.4]).

CONCLUSIONS

Intracoronary injection of ergonovine is safe and associated with a positivity rate of the test three times higher compared to intravenous injection.

Decreased resting coronary flow and impaired endothelial function in patients with vasospastic angina

OBJECTIVES

Coronary endothelial and circulatory dysfunction plays important roles in the pathogenesis of vasospastic angina (VSA). However, a complete understanding of the entire coronary circulation including microvasculature in patients with VSA is lacking.

PATIENTS AND METHODS

A total of 32 patients without obstructive coronary artery disease in the left descending coronary artery, who underwent an intracoronary acetylcholine (ACh) provocation test for diagnosis of VSA, were enrolled prospectively. A positive diagnosis of the ACh test was defined as total/subtotal coronary artery narrowing accompanied by chest pain and/or ischemic ECG changes. Angina frequency and severity at baseline, and 1 and 3 months were recorded. Coronary circulation was evaluated invasively using a thermodilution method by obtaining the mean transit time (Tmn) at rest and hyperemia, coronary flow reserve, and index of microcirculatory resistance. Systemic endothelial function was assessed by the reactive hyperemia index.

RESULTS

There were 14 (44%) and 18 (56%) patients with and without a positive ACh provocation test. The baseline characteristics did not differ significantly between the two groups. Patients with VSA had a significantly lower reactive hyperemia index compared with those without VSA (1.70±0.33 vs. 2.12±0.53, P=0.02). Coronary flow reserve, index of microcirculatory resistance, and hyperemic Tmn were not different between the two groups, whereas resting Tmn was significantly longer in patients with VSA (1.20±0.44 vs. 0.71±0.37, P=0.002). Although the frequency and severity of angina improved from baseline to 1 and 3 months in patients with both positive and negative ACh tests, there was no difference between the two groups.

CONCLUSION

Patients with VSA had decreased resting coronary flow and impaired endothelial function.

How to Diagnose and Manage Angina Without Obstructive Coronary Artery Disease: Lessons from the British Heart Foundation CorMicA Trial

Patients with symptoms and/or signs of ischaemia but no obstructive coronary artery disease (INOCA) present a diagnostic and therapeutic challenge. Microvascular and/or vasospastic angina are the two most common causes of INOCA; however, invasive coronary angiography lacks the sensitivity to diagnose these functional coronary disorders. In this article, the authors summarise the rationale for invasive testing in the absence of obstructive coronary disease, namely that correct treatment for angina patients starts with the correct diagnosis. They provide insights from the CORonary MICrovascular Angina (CorMicA) study, where an interventional diagnostic procedure was performed with linked medical therapy to improve patient health. Identification of these distinct disorders (microvascular angina, vasospastic angina or non-cardiac chest pain) is key for stratifying INOCA patients, allowing prognostic insights and better patient care with linked therapy based on contemporary guidelines. Finally, they propose a framework to diagnose and manage patients in this common clinical scenario.

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

Background

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

Methods

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

Results

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

Conclusion

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

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.

Blunted heart rate recovery is associated with coronary artery spasm in patients with suspected vasospastic angina

Background

Autonomic nervous system activity has been shown to be altered in patients with vasospastic angina (VA). Heart rate recovery (HRR) is a simple, non-invasive measurement of autonomic nervous system dysfunction. We aimed to investigate whether HRR is related to VA, as established by an ergonovine test.

Methods

A total of 976 consecutive patients (47.5% male, mean age 55 years) without significant coronary artery disease who underwent both an ergonovine provocation test and a treadmill exercise test were enrolled. The relationship between VA and HRR was evaluated.

Results

A total of 30.7% (300/976) of patients were diagnosed with VA, as documented by the ergonovine provocation test. HRR was significantly reduced in patients with VA compared to patients without VA (24.6 ± 18.0 vs. 30.5 ± 22.2, p < 0.001), and HRR was lowest in patients with multi-vessel spasm (21.9 ± 17.3). The proportion of blunted HRR, which was defined as HRR less than 12 beats, was significantly higher in patients with VA than in those without coronary artery spasm (26.6% vs. 39.3%, p < 0.001). In multivariable regression analyses, age (odds ratio (OR) = 1.03; 95% confidence interval (CI): 1.01–1.04; p = 0.001), blunted HRR (OR = 1.71; 95% CI: 1.26–2.31; p < 0.001), current smoking status (OR = 2.11; 95% CI: 1.50–2.98; p < 0.001), and male gender (OR = 2.00; 95% CI: 1.43–2.78; p < 0.001) were significant independent predictors of VA presence.

Conclusion

Blunted HRR was an independent predictor of VA presence, which suggests a link between coronary artery spasm and autonomic dysregulation.

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

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

The Impact of Subclinical Hypothyroidism or Thyroid Autoimmunity on Coronary Vasospasm in Patients without Associated Cardiovascular Risk Factors

Background and Objectives

Subclinical hypothyroidism is associated with endothelial dysfunction and impaired coronary flow reserve. However, the effect of subclinical hypothyroidism or thyroid autoimmunity on variant angina has yet to be determined.

Subjects and Methods

Among 385 consecutive patients without associated cardiovascular risk factors who underwent coronary angiography with the ergonovine provocation test (EPT), 165 had a positive EPT {EPT(+)} and 220 had a negative EPT {EPT(-)}. The relationship between coronary artery spasm and the presence of subclinical thyroid dysfunction as well as serum thyroid peroxidase autoantibody (TPO Ab) was evaluated.

Results

The proportion of patients with subclinical hypothyroidism among those who were EPT(+) was significantly higher than that in those who were EPT(-) (18% vs. 11%, p=0.001). However, there was no significant difference in the proportion of patients with subclinical hyperthyroidism between the groups. Moreover, EPT(+) patients showed significantly more positive TPO Ab (33% vs. 14%, p<0.001) than those with EPT(-). There was a positive correlation between EPT(+) and TPO positivity (r=0.226, p<0.001), subclinical hypothyroidism (r=0.112, p=0.033), and body mass index (r=0.123, p=0.018). Binary logistic regression analysis revealed that the significant predictors of EPT(+) were body mass index {adjusted odds ratio (OR)=1.042, 95% confidence interval (CI)=1.005-1.080}, presence of subclinical hypothyroidism (OR=3.047, 95% CI=1.083-8.572), TPO Ab titer (OR=1.028, 95% CI=1.015-1.041), and the presence of TPO Ab (OR=4.904, 95% CI=1.544-15.567).

Conclusion

Subclinical hypothyroidism and the presence of TPO Ab are significantly associated with coronary vasospasm in patients without cardiovascular risk factors.

Single-wire pressure and flow velocity measurement for quantifying microvascular dysfunction in patients with coronary vasospastic angina

Endothelial and vascular smooth muscle dysfunction of epicardial coronary arteries play a pivotal role in the pathogenesis of vasospastic angina (VSA). However, coronary microvascular (MV) function in patients with VSA is not fully understood. In the present study, subjects without coronary obstruction were divided into two groups according to the acetylcholine provocation test: VSA group ( n = 29) and non-VSA group ( n = 21). Hyperemic MV resistance (hMR) was measured using a dual-sensor (Doppler velocity and pressure)-equipped guidewire, and guidewire-derived hemodynamic parameters were compared. There were no between-group differences in clinical demographics, including potential factors affecting MV function (e.g., diabetes). Although coronary flow velocity reserve was similar between the two groups [2.4 ± 1.0 (VSA group) vs. 2.4 ± 0.9 (non-VSA group); P = 0.8], coronary vessel resistance and hMR were significantly elevated in the VSA group compared with the non-VSA group (2.6 ± 3.1 vs. 1.2 ± 0.8, P = 0.04; 1.9 ± 0.6 vs. 1.6 ± 0.5, P = 0.03, respectively). Coronary vasospasm, older age, E/e', and estimated glomerular filtration rate were significantly associated with MV dysfunction [defined as ≥ median value of hMR (1.6)] in univariate analysis. Coronary vasospasm most strongly predicted higher hMR in multivariate logistic regression analysis (odds ratio, 4.61; 95% confidence interval, 0.98–21.60; P = 0.053). In conclusion, coronary MV resistance is impaired in patients with VSA compared with non-VSA patients, whereas coronary flow velocity reserve is maintained at normal levels in both groups. In vivo assessment of hMR might be a promising index of coronary MV dysfunction in patients with VSA.

Provocative testing for coronary reactivity and spasm

Coronary spasm is an important and often overlooked etiology of chest pain. Although coronary spasm, or Prinzmetal's angina, has been thought of as benign, contemporary studies have shown serious associated adverse outcomes, including acute coronary syndrome, arrhythmia, and death. Definitive diagnosis of coronary spasm can at times be difficult, given the transience of symptoms. Numerous agents have been historically described for provocative testing. We provide a review of published data for the role of provocation testing in the diagnosis of coronary spasm.

Tako-tsubo cardiomyopathy after administration of ergometrine following elective caesarean delivery: a case report

Introduction

Tako-tsubo cardiomyopathy (stress-induced cardiomyopathy or transient left ventricular ballooning) is characterized by clinical suspicion of an acute myocardial infarction with transient apical or midventricular dyskinesia of the left ventricle without significant coronary stenosis on angiography. The etiology of this disease remains obscure. One of the possible causes is myocardial ischemia induced by coronary vasospasm due to sympathetic activation. It has been hypothesized that the application of ergometrine could induce tako-tsubo cardiomyopathy.

Case presentation

We report the case of a 28-year-old Turkish woman who developed tako-tsubo cardiomyopathy after administration of ergometrine for release of placenta and prevention of bleeding during the post-partum phase in the course of an elective caesarean delivery. Tako-tsubo cardiomyopathy was diagnosed by echocardiography and urgent cardiac magnetic resonance imaging. A coronary angiography was not performed because of the absence of myocardial necrosis or ischemia and signs of myocarditis on cardiac magnetic resonance imaging.

Conclusion

This life-threatening disease should be excluded in the differential diagnosis by comparing the symptoms with those of typical heart failure, particularly after use of ergometrine.

Gender differences among korean patients with coronary spasm

BACKGROUND AND OBJECTIVES

The gender differences among Korean patients with coronary spasm have not been defined. We thus determined the gender differences among Korean patients with coronary spasm.

SUBJECTS AND METHODS

Patients with chest pain and/or syncope who were admitted to Kyungpook National University Hospital between January 2001 and August 2008 were included. Provocation of coronary vasospasm with intracoronary ergonovine maleate was performed when baseline coronary angiography showed no significant stenosis or there was a strong clinical suspicion of coronary spasm. The clinical characteristics were analyzed from 104 consecutive patients (56+/-9 years of age; 21 females) who were diagnosed with coronary spasm.

RESULTS

Female patients were younger (52+/-7 vs. 57+/-10 years, p=0.046) with lower rates of smoking and alcohol consumption histories than male patients (19% vs. 65%, p<0.001; and 43% vs. 89%, p<0.001, respectively). The other clinical characteristics were not significantly different, except for the triglyceride levels.

CONCLUSION

The majority of patients with coronary spasm were males who were smokers and alcohol consumers. The female patients had lower rates of smoking and alcohol consumption, and they were younger than the male patients. Further studies are needed to investigate the relevance of gender differences in the pathogenesis of coronary spasm.

Coronary vasospasm produces reversible perfusion defects observed during adenosine triphosphate stress myocardial single-photon emission computed tomography

BACKGROUND

Adenosine triphosphate stress thallium-201 single-photon emission computed tomography (ATP-SPECT) is useful for diagnosing coronary artery disease (CAD), although sometimes false positive results are observed. It has not been established whether a coronary spasm is responsible for the false positive findings during ATP-SPECT.

HYPOTHESIS

We investigated whether coronary spasm is one of the factors which produces reversible defects on ATP-SPECT.

METHODS

Eighty-six patients (mean age: 62 y; 58 men) who underwent both spasm-provocation testing by coronary angiography and ATP-SPECT, were selected for the study. Patients with coronary narrowing (>30%), myocardial infarction, or heart failure were excluded. Patients were divided into 2 groups based on whether the spasm-provocation test result was positive (vasospastic angina [VSA] group, n = 46) or negative (non-VSA group, n = 39).

RESULTS

The body mass index was lower in the VSA group than in the non-VSA group (p = 0.005). On ATP-SPECT imaging, any type of reversible defect was observed more frequently in the VSA group (68%) than in the non-VSA group (36%, p = 0.0027). Logistic regression analysis demonstrated that the presence of reversible defects was one of the factors accounting for the presence of coronary vasospasm (p = 0.0022, R2 = 0.172).

CONCLUSIONS

The findings suggest that reversible defects on ATP-SPECT imaging are frequently present in patients with coronary vasospasm. Coronary spasm may be considered as 1 of the factors, which produce reversible defects on ATP-SPECT, observed in patients with chest symptoms and angiographically normal coronary arteries.

Non-invasive assessment of coronary arterial tone using trans-thoracic Doppler echocardiography

BACKGROUND

As coronary flow velocity (CFV) is inversely related to the luminal size that exists for the myocardial bed, the elevated arterial tone can be assessed as the higher flow velocity in the epicardial artery. We examined the usefulness of transthoracic Doppler echocardiography (TTDE) for the assessment of coronary arterial tone.

METHODS AND RESULTS

A total of 32 patients underwent TTDE and angiography. The luminal diameter (LD) in the left anterior descending artery (LAD) was measured by using quantitative coronary angiography before and after nitroglycerin (NTG) administration. The ratio of post NTG LD to the control (LD(NTG/Pre)) was assessed as a standard parameter of coronary arterial tone. We also measured CFV and CFV reserve (CFVR) at the LAD by TTDE. We evaluated the change of CFV (CFV(NTG/Pre)) and CFVR (CFVR(NTG/Pre)) following NTG administration. The LD increased from 1.98+/-0.46 to 2.51+/-0.34 mm (p<0.001), while the CFV decreased from 23.9+/-10.0 to 16.3+/-5.6 cm/s (p<0.03), and the CFVR increased from 2.39+/-0.65 to 3.56+/-1.12 (p<0.001). There were significant correlations between CFV(NTG/Pre) and LD(NTG/Pre) (p<0.0001, R2 = 0.532), and between the CFVR(NTG/Pre) and LD(NTG/Pre) (p<0.0001, R2 = 0.715).

CONCLUSION

TTDE can assess the coronary arterial tone by measuring the responses of CFV and CFVR to NTG administration.

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.

Induction of coronary artery spasm by two pharmacological agents: comparison between intracoronary injection of acetylcholine and ergonovine

BACKGROUND AND OBJECTIVES

There have been few studies comparing the clinical usefulness for the induction of coronary artery spasm (CAS) between acetylcholine (ACh) and ergonovine (ER). This study is designed: (1) to examine the duration of effect after intracoronary injection of ACh on the responsible vessels using a 0.014 inch, 15 MHz Doppler guide wire, and (2) to evaluate the efficacy of two pharmacological agents, ACh and ER, for the induction of CAS in patients with <50% stenosis in the cardiac laboratory.

METHODS

Phasic coronary flow velocity patterns were recorded at rest and during ACh tests in 22 patients with normal or near-normal coronary arteries. The tip of the guide wire was placed on the proximal right coronary artery (RCA) and mid-left anterior descending artery. We measured the time required to baseline level of average peak velocity after intracoronary injection of ACh. We performed selective intracoronary administration of both ER and ACh in the same 171 patients (106 men, 65 women, mean age of 62+/-10 years) with <50% stenosis. Under no medication, ACh was injected first in incremental doses of 20, 50, and 80 microg into the RCA and of 20, 50, and 100 microg into the left coronary artery (LCA). Ten minutes later, ER was administered at 10 microg/min for four minutes for a maximal dose of 40 microg on the RCA and at 16 microg/min over four minutes for a total dose of 64 microg on the LCA. Positive spasm was defined as > or =99% luminal narrowing.

RESULTS

The time-averaged peak velocity returned to baseline after intracoronary injection of ACh within 10 minutes in all 120 procedures, consisted of 19 with positive spasm (RCA (n=10): 245+/-33 s; LCA (n=9): 351+/-187 s) and 101 with negative spasm (RCA (n=48): 155+/-62 s, LCA (n=53): 248+/-106 s). In the overall results, there was no difference concerning the incidence of provoked spasm between the two pharmacological agents (ACh: 33% versus ER: 32%, NS). Coronary spasms were induced by either pharmacological agent in 134 vessels. Concordance in this study was 94% in all vessels, whereas the remaining 6% of vessels were different from each other. The non-concordance rate of the right coronary artery was significantly higher than that of the left coronary artery (10% versus 4%, p<0.01). However, ER provoked more focal spasms, whereas ACh provoked more diffuse and distal spasms, compared with each other. Seventy-four (55%) of the 134 vessels had coronary spasms in the same coronary arteries. Concordance of both provoked spasm sites and spasm configurations in the same coronary artery was observed in only 18 (13%) vessels. No serious or irreversible complications were observed during the two sequential tests.

CONCLUSIONS

As a spasm provocation test, there were no differences between ACh and ER. We recommend the supplementary use of these two pharmacological agents for the induction of CAS in the cardiac laboratory, if available.

Diffuse and severe left ventricular dysfunction induced by epicardial coronary artery spasm

Endothelial dysfunction and effectiveness of treatment of calcium antagonists are suggestive of coronary artery spasm as an underlying disorder in dilated cardiomyopathy (DCM). The aim of this study is to determine whether or not the epicardial coronary artery spasm can induce severe cardiac dysfunction like DCM. Thirty-four consecutive patients with angiographically normal coronary arteries and diffuse left ventricular hypokinesis whose causes had been unknown underwent acetylcholine provocation test and left ventricular biopsy. Eight patients were excluded according to the clinical and laboratory data and biopsy findings suggesting myocarditis or other systemic diseases. According to the results of the acetylcholine provocation test, 17 patients were finally diagnosed as having DCM, and nine patients (35% of the study patients), who had acetylcholine-induced diffuse and multivessel coronary spasm, were diagnosed as having DCM-like vasospastic angina pectoris (VSA). Clinical and cardiac catheterization data including hemodynamics and biopsy findings were similar between the two groups except that left ventricular end-systolic volume was significantly greater in DCM than in DCM-like VSA. After the acetylcholine provocation test, DCM patients received both a beta blocker and an angiotensin-converting enzyme inhibitor, and DCM-like VSA patients received antianginal drugs. In echocardiographic findings at predischarge and those after 6-month drug treatment, both DCM-lke VSA and DCM showed significant reduction in end-diastolic and end-systolic diameters and significant increase in fractional shortening and ejection fraction, whereas changes in ejection fraction and fractional shortening were significantly greater in DCM-like VSA than those in DCM. Epicardial coronary artery spasm can induce diffuse and severe left ventricular dysfunction like DCM in VSA. Although antianginal drugs markedly improve left ventricular function of these patients, only the acetylcholine provocation test can identify DCM-like VSA.

Clinical characteristics of female patients with coronary spastic angina: comparison with male patients

There are many patients with vasospastic angina who have minor atherosclerosis, and in Japan the majority of them are male. No data exist concerning sex differences in patients with coronary spastic angina, so the present study sought to clarify the clinical characteristics between male and female patients with vasospastic angina. Between April 1991 and June 1998, 204 consecutive patients were diagnosed with vasospastic angina and of these, 26 (12.7%) were female. An acetylcholine test was performed with incremental doses of 20, 50, and 80 microg injected into the right coronary artery and 20, 50, and 100 microg into the left coronary artery. Ergonovine was injected in a total dose of 40 microg into the right coronary artery and 64 microg into the left coronary artery. Coronary spasm was defined as 99% or more luminal narrowing accompanied by ischemic changes on ECG. Compared with male patients, female patients had less organic stenosis (12 vs 33%, p<0.05), less history of smoking (15 vs 85%, p<0.01), and fewer focal spasms (31 vs 64%, p<0.01). There were no other differences between the 2 groups. In conclusion, Japanese female patients with vasospastic angina had the characteristics of diffuse provoked spasm, less organic stenosis, and less history of smoking, but only 1 in 10 of all patients with vasospastic angina are female.

Differences between coronary hyperresponsiveness to ergonovine and vasospastic angina

The objective of the present study was to investigate the differences between coronary hyperresponsiveness without ischemia and vasospastic angina in an ergonovine provocation test using multivariate analysis. We have sometimes experienced a more than 50% narrowing response of vascular diameter without ischemia in a coronary response to ergonovine. We studied 107 patients with less than 50% stenosis in a coronary arteriogram. Their vascular responses to ergonovine were measured and the patients were divided into three groups, as follows: Group 1 had 50% or less vascular narrowing response without ischemia; Group 2 had a vascular hyperresponsiveness of more than 50% narrowing response without ischemia; and Group 3 experienced a hyperresponsiveness with ischemia. The degree of coronary response was found to be related to smoking, inpaired glucose tolerance (IGT) and the Gensini score by multiple regression analysis. A multiple logistic analysis revealed that the Gensini score and smoking were significant predictive factors for Group 3 (odds ratio: 1.20 and 8.97). The only factor different between Group 2 and Group 1 was gender. The coronary hyperresponsiveness to ergonovine without ischemia differs from vasospastic angina in the degree of coronary atherosclerosis and smoking habits. The patients with hyperresponsiveness had similar characteristics to those with atypical chest pain rather than vasospastic angina, except for a gender difference.

Restricted coronary flow reserve in patients with mitral regurgitation improves after mitral reconstructive surgery

OBJECTIVES

The purpose of this study was to assess coronary flow characteristics in patients with chronic mitral regurgitation (MR).

BACKGROUND

Coronary flow reserve (CFR) has been reported to be restricted in cases with left ventricular (LV) volume overload caused by aortic regurgitation and increased LV preload.

METHODS

The study populations consisted of 31 patients with nonrheumatic chronic MR. Eleven with chest pain and normal coronary arteries served as control subjects. Phasic coronary flow velocities were obtained in the proximal segment of the angiographically normal left anterior descending coronary artery at rest and during hyperemia (0.14 mg/kg/min adenosine infusion intravenously) using a 0.014-in. (0.036 cm), 15-MHz Doppler guide wire. Coronary flow reserve was obtained from the ratio of hyperemic/baseline time-averaged peak velocity (APV). Thirteen cases who underwent mitral valve reconstructive surgery were also studied 1 month after surgery.

RESULTS

Compared with control subjects, CFR was significantly reduced in cases with MR (2.1+/-0.5 vs. 33+/-0.6, respectively, p < 0.01) because baseline APV was significantly greater (28+/-8 vs. 19+/-6 cm/s, respectively, p < 0.01), although maximal hyperemic APV was not significantly different (56+/-14 vs. 61+/-16 cm/s, respectively, p = NS). Significant correlations were obtained between CFR and LV end-diastolic pressure (LVEDP) (r = 0.70, p < 0.01), LV mass index (r = 0.42, p < 0.01), LV end-diastolic volume (r = 038, p = 0.04) and MR volume (r = 0.39, p = 0.03), and stepwise regression analysis showed LVEDP was the most important determinant of CFR in MR (r2 = 0.49, p < 0.0001). This restricted CFR improved significantly after mitral valve reconstructive surgery (2.1+/-0.5 vs. 3.1+/-0.6, respectively, p < 0.01) because of reduction of baseline APV (28+/-8 vs. 21+/-8 cm/s, respectively, p < 0.01).

CONCLUSIONS

Coronary flow reserve is limited in cases with MR because of elevation of baseline resting flow velocity. This reduction of CFR correlates well with increase in LV preload, mass and volume overload, especially with increase in LV preload, and this restricted CFR improves after mitral valve surgery.

Noninvasive assessment of coronary flow velocity and coronary flow velocity reserve in the left anterior descending coronary artery by Doppler echocardiography: comparison with invasive technique

OBJECTIVES

The purpose of this study was to evaluate whether transthoracic Doppler echocardiography (TTDE) can reliably measure coronary flow velocity (CFV) and coronary flow velocity reserve (CFVR) in the left anterior descending coronary artery (LAD) in the clinical setting.

BACKGROUND

Coronary flow velocity measurement has provided useful clinical and physiologic information. Advancement in TTDE provides noninvasive measurement of CFV and CFVR in the distal LAD.

METHODS

In 23 patients, CFV in the distal LAD was measured by TTDE (5 or 3.5 MHz) under the guidance of color Doppler flow mapping at the time of Doppler guide wire (DGW) examination. Coronary flow velocity in the distal LAD were measured at baseline and hyperemic conditions (intravenous administration of adenosine 0.14 mg/kg/min) by both TTDE and DGW techniques. Coronary flow velocity reserve was defined as the ratio of peak hyperemic to basal averaged peak velocity in the distal LAD.

RESULTS

Clear envelopes of basal and hyperemic CFV in the distal LAD were obtained in 18 (78%) of 23 study patients by TTDE. There were excellent correlations between TTDE and DGW methods for the measurements of CFV (averaged peak velocity: r=0.97, y=0.94x + 0.40; averaged diastolic peak velocity: r=0.97, y=0.94x + 0.69; systolic peak velocities: r=0.97, y=0.91x + 0.87; diastolic peak velocity: r=0.98, y=0.95x + 1.10). Coronary flow velocity reserve from TTDE correlated highly with those from DGW examinations (r=0.94, y=0.95x + 0.21).

CONCLUSIONS

Noninvasive measurement of CFV and CFVR in the distal LAD using TTDE accurately reflects invasive measurement of CFV and CFVR by DGW method.