Effects of intracoronary injection of ergonovine on angiographic normal coronary arteries: study of 108 consecutive patients

Meta-analysis and systematic review of coronary vasospasm in ANOCA patients: Prevalence, clinical features and prognosis

Background

Coronary artery spasm (CAS), encompassing epicardial and microvascular spasm, is increasingly recognized as cause of angina in patients with non-obstructive coronary artery disease (ANOCA). However, various spasm provocation testing protocols and diagnostic criteria are used, making diagnosis and characterization of these patients difficult and interpretation of study results cumbersome. This review provides a structured overview of the prevalence, characterization and prognosis of CAS worldwide in men and women.

Methods

A systematic review identifying studies describing ANOCA patients with CAS was performed. Multiple outcomes (prevalence, clinical features, and prognosis) were assessed. Data, except for prognosis were pooled and analysed using random effects meta-analysis models.

Results

Twenty-five publications (N = 14.554) were included (58.2 years; 44.2% women). Percentages of epicardial constriction to define epicardial spasm ranged from >50% to >90%. Epicardial spasm was prevalent in 43% (range 16-73%), with a higher prevalence in Asian vs. Western World population (52% vs. 33%, p = 0.014). Microvascular spasm was prevalent in 25% (range 7-39%). Men were more likely to have epicardial spasm (61%), women were more likely to have microvascular spasm (64%). Recurrent angina is frequently reported during follow-up ranging from 10 to 53%.

Conclusion

CAS is highly prevalent in ANOCA patients, where men more often have epicardial spasm, women more often have microvascular spasm. A higher prevalence of epicardial spasm is demonstrated in the Asian population compared to the Western World. The prevalence of CAS is high, emphasizing the use of unambiguous study protocols and diagnostic criteria and highlights the importance of routine evaluation of CAS in men and women with ANOCA.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=272100.

Non-invasive diagnosis of vasospastic angina

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

Myocardial Ischemic Syndromes, Heart Failure Syndromes, Electrocardiographic Abnormalities, Arrhythmic Syndromes and Angiographic Diagnosis of Coronary Artery Spasm: Literature Review

In coronary artery spasm (CAS), an excess coronary vasoconstriction causing total or subtotal vessel occlusion could lead to syncope, heart failure syndromes, arrhythmic syndromes, and myocardial ischemic syndromes including asymptomatic myocardial ischemia, stable and unstable angina, acute myocardial infarction, and sudden cardiac death. Although the clinical significance of CAS has been underrated because of the frequent absence of symptoms, affected patients appear to be at higher risk of syncope, serious arrhythmias, and sudden death than those with classic Heberden's angina pectoris. Therefore, a prompt diagnosis has important therapeutic implications, and is needed to avoid CAS-related complications. While a definitive diagnosis is based mainly on coronary angiography and provocative testing, clinical features may help guide decision-making. We perform a literature review to assess the past and current state of knowledge regarding the clinical features, electrocardiographic abnormalities and angiographic diagnosis of CAS, while a discussion of mechanisms is beyond the scope of this review.

Differential Incidence and Morphology of Spasm According to Coronary Arterial Location by Intracoronary Ergonovine Spasm Provocation Testing

BACKGROUND

We reported less provoked spasm in the left circumflex artery (LCX) by acetylcholine testing compared with the left anterior descending artery (LAD) and right coronary artery (RCA), so we investigated the clinical characteristics of provoked spasm in the LCX by ergonovine (ER) testing.Methods and Results:We retrospectively analyzed 1,185 consecutive cases of intracoronary ER testing during 25 years. Maximal ER dose was 64 μg into the left coronary artery (LCA) and 40 μg into the RCA. Positive spasm was defined as a transient ≥90% narrowing and usual chest symptoms or ischemic ECG changes. Positive provoked spasm was recognized in 347 patients (29.3%), including 207 RCA spasms, 166 LAD spasms, and 79 LCX spasms. Spasm was provoked in the LCX significantly less than in the other vessels (P<0.001). LCX-provoked spasm was obtained in 79 patients consisting of 16 patients (20.3%) with triple-vessel spasm, 38 patients (48.1%) with double-vessel spasm and 25 patients (31.6%) with single-vessel spasm. Less than 70% patients with LCX-provoked spasm had multiple spasms, whereas approximately 60% patients had single-vessel spasm in the RCA (64.3%) or LAD (59.6%). In 25 patients with LCX single-vessel spasm, 18 patients (72.0%) had a focal spasm.

CONCLUSIONS

Under maximal ER dose of 64 μg into the LCA, LCX-provoked spasm occurred significantly less than spasm in the other vessels and less than 70% patients had multiple spasms.

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

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

Overview of complications during pharmacological spasm provocation tests

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

[Diagnosis and treatment of spastic angina revealed by cardiac arrest]

The prevalence of vasospastic angina is said to be low in Europe, but maybe because of a lack of diagnosis in the daily practice. However, coronary spasm is a common cause of cardiac arrest, especially among patients free of cardiac illness, and it should be systematically investigated after an unexplained cardiac arrest. Intracoronary spasm provocation test exposes patients to a lower risk compared to the risk of spontaneous spastic angina. Accurate modalities and diagnostic criteria have to be clarified for European population. Avoiding external causes of coronary spasm (such as cigarette smoking or more generally consuming coronary spasm inducing drugs) and prescribing antispastic medicine (first of all calcium channel blockers) are the basis of vasospastic angina treatment. However, recurrent coronary spasms have been reported despite an appropriate treatment and implantable automatic defibrillator has been implanted after case discussion when the onset of illness was cardiac arrest. We report the case of a patient recovering from cardiac arrest who had a positive spasm coronary provocation test, and was treated with calcium channel blockers and had been an automatic defibrillator implanted, with a coronary spasm provocation test performed afterward still contentious. While discussing this case, we are making a literature review of the diagnosis and treatment of spastic angina revealed by cardiac arrest.

Coronary artery spasm: review and update

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

Feasibility and safety of the transradial approach for the intracoronary spasm provocation test

An angiography-based spasm provocation test is an accurate diagnostic test of coronary vasospastic angina, but is associated with high patient morbidity, mainly because of the femoral approach and the need for a temporary pacemaker. The purpose of this study was to investigate the safety and feasibility of a transradial ergonovine spasm provocation test. The test was performed prospectively in 174 consecutive patients who were under suspicion of coronary vasospasm at our institution from April 2002 to June 2003. Seventy-eight out of 174 procedures (45%) were performed in an outpatient department. The procedural success rate was 168/174 (96%). All failures were because of access failures, and no major complications were noted. Minor complications were observed in nine patients (severe bradycardia in three, hypotension in two, both in two, and nonsustained ventricular tachycardia in two). The incidence of complications was higher in patients showing prolonged spasm in the right coronary artery. No major local complication was noted other than rebleeding in the puncture site during hemostasis in one patient. The transradial spasm provocation test performed without using a temporary pacemaker may be feasible and safe, with a high success rate and low complication rate as well as low patient morbidity.

The role of coronary endothelial function testing in patients suspected for angina pectoris

Coronary vasomotor function plays an important role in onset and progression of coronary artery disease. Suwaidi [Circulation 101 (2000) 948] and Schächinger [Circulation 101 (2000) 1899] demonstrated that vasomotor dysfunction has a significant impact on events in patients with minimal coronary artery disease. Endothelial specific testing can be performed in coronary as well as peripheral arteries. However, non-coronary tests have a low correlation with the coronary vasomotor response, as assessed by acetylcholine. In large clinical prospective placebo-controlled trials, angiotensin-converting enzyme (ACE) inhibitors and lipid-lowering drugs reduce morbidity and mortality after myocardial infarction or myocardial infarction-induced heart failure. The same drugs restore endothelial dysfunction after myocardial infarction, as was demonstrated in small experimental and clinical studies. Recent studies in patients with coronary artery disease showed a relation with endothelial dysfunction and the occurrence of adverse coronary events. For this reason, it is important to develop methods to evaluate endothelial function.

Safety evaluation of routine intracoronary acetylcholine infusion in patients undergoing a first diagnostic coronary angiogram

BACKGROUND

Recent findings imply prognostic significance of intracoronary acetylcholine infusion for endothelial function testing. We evaluated whether routine use of this test in coronary angiography patients is safe.

METHODS

Patients undergoing a first diagnostic coronary angiography were selected to receive intracoronary acetylcholine for endothelial function evaluation. The relation between adverse reactions during infusion and risk factors was analyzed with a logistic regression model. Included in the multiple logistic regression model were the variables with a univariate P value < 0.20.

RESULTS

Adverse reactions occurred in 16% (49/299) of the patients. This included two life-threatening events caused by occlusive spasm and flow limitation in the left coronary artery. Other adverse events were chest pain (n = 38), AV block or sinus bradycardia (n = 10), dyspnea (n = 3). Adverse reactions were more likely to occur in patients younger than 60 years of age (relative risk, 5.6 [2.2-14.3]).

CONCLUSION

Intracoronary acetylcholine infusion is safe, but may lead to serious adverse reactions. Care should be taken especially in patients younger than 60 years of age. Routine use of acetylcholine infusion can thus only be justified if it has important prognostic significance. This has to be proven further in large prospective studies.

Selective ergonovine-induced coronary artery spasm and ST-segment alternans after blunt thoracic trauma

A 24-year-old man was found to have angiographically normal coronary arteries shortly after suffering blunt thoracic trauma. Selective ergonovine administration into the left coronary artery induced total occlusion of the left anterior descending branch and electrical alternans of the ST-segment. This case demonstrates coronary artery spasm as a possible mechanism of coronary occlusion after blunt thoracic trauma.

Comparison of coronary responses to intracoronary and intraaortic ergonovine and isosorbide dinitrate in patients with atypical chest pain

Fifty patients with atypical chest pain were studied to compare coronary responses to intracoronary and intraaortic ergonovine. The diameters of the proximal, middle (1) and (2) (proximal segments of segments 2 and 3 [AHA classification], respectively), and distal segments of the right coronary artery were measured before and after intracoronary ergonovine (4 micrograms/minute over 4 minutes) and isosorbide dinitrate (ISDN) (2 mg) in 24 patients, and before and after intraaortic ergonovine (0.2 mg) and ISDN (5 mg) in 26. Mean vasoconstriction by intracoronary and intraaortic ergonovine were 13 +/- 1.5% and 9 +/- 0.8%, respectively (p < 0.02). Irrespective of the methods of administration, the responses to ergonovine were similar in the 4 segments. Mean vasodilation by intracoronary and intraaortic ISDN, which were used to quantify the degree of basal coronary tone, were 25 +/- 2.2% and 27 +/- 1.5%, respectively (p = not significant [NS]). There were significant negative linear correlations between the responses to ergonovine and ISDN in the middle (2) (r = -0.51; p < 0.05) and distal (r = -0.53; p < 0.01) segments in patients with intracoronary injection, and the proximal (r = -0.41; p < 0.05), middle (1) (r = -0.66; p < 0.01) and middle (2) (r = -0.69; p < 0.01) segments in patients with intraaortic injection. These observations indicate that low-dose administration of intracoronary ergonovine produces sufficient coronary vasoconstriction, similar to or slightly greater than that of intraaortic ergonovine in patients with atypical chest pain, but basal coronary tone may influence the vasoreactivity to ergonovine.