Transitional changes of acetylcholine spasm provocation test procedures

Relation of Vasoreactivity in the Left and Right Coronary Arteries During Acetylcholine Spasm Provocation Testing

The diagnosis of vasospastic angina (VSA) according to Japanese guidelines involves an initial intracoronary acetylcholine (ACh) provocation test in the left coronary artery (LCA) followed by testing in the right coronary artery (RCA). However, global variations in test protocols often lead to the omission of ACh provocation in the RCA, potentially resulting in the underdiagnosis of VSA. This study assessed the validity of the LCA-only ACh provocation approach for the VSA diagnosis and whether vasoreactivity in the LCA aids in determining further provocation in the RCA. A total of 273 patients who underwent sequential intracoronary ACh provocation testing in the LCA and RCA were included. Patients with a positive ACh provocation test in the LCA were excluded. Relations between vasoreactivity in the LCA and ACh test outcomes (positivity and adverse events) in the RCA were evaluated. In patients with negative ACh test results in the LCA, subsequent ACh testing was positive in the RCA in 23 of 273 (8.4%) patients. In patients with minimal LCA vasoconstriction (<25%), only 3.0% had a positive ACh test in the RCA, whereas the ACh test in the RCA was positive in 13.5% of those with LCA constriction of 25% to 90% (p = 0.002). No major adverse events occurred during ACh testing in the RCA. In conclusion, for the VSA diagnosis, the omission of ACh provocation in the RCA may be clinically acceptable, particularly when vasoconstriction induced by ACh injection was minimal in the LCA. Further studies are needed to define ACh provocation protocols worldwide.

Omitting 50 μg of intracoronary acetylcholine injection in the left coronary artery during spasm provocation test

BACKGROUND

Although guidelines recommend intracoronary administration of acetylcholine (ACh) with incremental doses of 20, 50, and 100 μg into the left coronary artery (LCA) during spasm provocation test for diagnosing vasospastic angina, 50 μg of ACh rarely induced significant coronary vasospasm when no vasoconstriction was observed with 20 μg of ACh in a previous report. The aim of this study was to evaluate the safety and feasibility of omitting 50 μg according to the vasoreactivity by 20 μg of ACh in the LCA.

METHODS

A total of 556 patients undergoing ACh provocation test with 20 μg followed by 50 and/or 100 μg were retrospectively included. Injection of 50 μg of ACh was primarily omitted when vasoconstriction <25 % was observed with 20 μg, which was left to operator's discretion. Adverse events were defined as a composite of ventricular fibrillation, sustained ventricular tachycardia, and cardiogenic shock during ACh test in the LCA.

RESULTS

Positive ACh test in the LCA was observed in 245 (44.1 %) patients. Overall, patients with LCA constriction <25 % by 20 μg of ACh had a lower rate of positive ACh test than their counterpart (24.0 % vs. 88.4 %, p < 0.001). In patients with LCA constriction ≥25 % by 20 μg, the incidence of adverse events was significantly higher than in those with LCA constriction <25 % during the provocation test at doses of 50 and 100 μg (2.3 % vs. 0 %, p = 0.009).

CONCLUSIONS

Omitting 50 μg of ACh in the LCA may be safe and feasible when little vasoconstriction was observed with preceding injection of 20 μg of ACh during spasm provocation test for diagnosing vasospastic angina. However, we believe that 50 μg of ACh should not be omitted when 20 μg of ACh induced LCA constriction ≥25 %.

Insights into the invasive diagnostic challenges of coronary artery vasospasm - A systematic review

Coronary provocation testing is an essential diagnostic procedure when evaluating vasospastic angina. Invasive methods using acetylcholine or ergonovine are considered the current gold standard. Despite efforts from global cardiovascular institutions, current protocols vary in dosage, administration time, and procedural approach. In addition, concerns over the specificity of findings and potential complications have limited routine uptake of this procedure in clinical practice. This systematic review evaluates current diagnostic protocols, focusing on invasive provocation testing. We included studies using intracoronary provocation testing with acetylcholine or ergonovine for the assessment of coronary artery vasospasm that detailed specific elements of the procedure (dosage, administration time, etc.) and included ≥50 patients. A total of 28 articles met strict inclusion criteria. Our review highlights the heterogeneity between current diagnostic protocols for invasive provocation testing. We believe standardization of a diagnostic protocol will encourage both current and future cardiologists to incorporate such procedures in the evaluation of variant angina.

Implantable cardioverter-defibrillator therapy after resuscitation from cardiac arrest in vasospastic angina: A retrospective study

Patients with vasospastic angina (VSA) who are resuscitated from sudden cardiac arrest (SCA) are at a high risk of recurrent lethal arrhythmia and cardiovascular events. However, the benefit of the implantable cardioverter-defibrillator (ICD) therapy in this population has not been fully elucidated. The present study aimed to analyze the prognostic impact of ICD therapy on patients with VSA and SCA. A total of 280 patients who were resuscitated from SCA and received an ICD for secondary prophylaxis were included in the present multicenter registry. The patients were divided into two groups on the basis of the presence of VSA. The primary endpoint was a composite of all-cause death and appropriate ICD therapy (appropriate anti-tachycardia pacing and shock) for recurrent ventricular arrhythmias. Of 280 patients, 51 (18%) had VSA. Among those without VSA, ischemic cardiomyopathy was the main cause of SCA (38%), followed by non-ischemic cardiomyopathies (18%) and Brugada syndrome (7%). Twenty-three (8%) patients were dead and 72 (26%) received appropriate ICD therapy during a median follow-up period of 3.8 years. There was no significant difference in the incidence of the primary endpoint between patients with and without VSA (24% vs. 33%, p = 0.19). In a cohort of patients who received an ICD for secondary prophylaxis, long-term clinical outcomes were not different between those with VSA and those with other cardiac diseases after SCA, suggesting ICD therapy may be considered in patients with VSA and those with other etiologies who were resuscitated from SCA.

Resistive reserve ratio and microvascular resistance reserve in patients with coronary vasospastic angina

Patients with epicardial coronary vasospastic angina (VSA) may be likely to have coronary microvascular dysfunction, although mixed results have been reported. The aim of this study was to evaluate coronary microvascular function in detail using novel invasive physiologic indices, such as resistive reserve ratio (RRR) and microvascular resistance reserve (MRR). A total of 45 patients undergoing intracoronary acetylcholine (ACh) provocation test and invasive coronary circulatory evaluation using a thermodilution method were prospectively included. VSA was diagnosed as angiographic vasospasm accompanied by chest pain and/or ischemic electrocardiographic changes by intracoronary injection of ACh. Coronary circulation was assessed with physiologic indices including fractional flow reserve, resting and hyperemic mean transit time (Tmn), coronary flow reserve (CFR), basal resistance index, index of microcirculatory resistance (IMR), RRR, and MRR. Of 45 patients, 23 (51.1%) were diagnosed as having VSA. Patients with positive ACh test had longer resting Tmn (slower coronary flow velocity), higher basal resistance index, and greater RRR and MRR than those without, while fractional flow reserve, CFR, and IMR did not differ significantly between the two groups. In conclusion, although conventional measures such as CFR and IMR failed to show significant differences, RRR and MRR, novel invasive coronary physiologic indices, provided counterintuitive insights that coronary microvascular dilation function was better preserved in patients with VSA than those without.

Gender differences in factors associated with vasospastic angina

BACKGROUND

Vasospastic angina (VSA) is reportedly associated with several clinical characteristics such as smoking and high-density lipoprotein (HDL) cholesterol, in which gender differences are present. For instance, smoking rates among men are higher than those among women, and a normal range of HDL cholesterol differs across genders. However, their impact between men and women on VSA is unclear.

METHODS

A total of 797 patients (427 men and 370 women) undergoing intracoronary acetylcholine (ACh) provocation test to diagnose VSA were included. The positive ACh provocation test was defined as angiographic vasospasm accompanied by chest pain and/or ischemic electrocardiographic changes. Factors contributing to VSA across genders were evaluated by multivariable analyses.

RESULTS

Of 797 patients, 414 (51.9%) had positive ACh provocation test. The incidence of positive ACh test was higher in men than in women (56.9% vs. 46.2%, p = 0.003). In the entire study population, current smoking and a lower HDL cholesterol level were determined as factors associated with VSA. In both men and women, an HDL cholesterol level was identified as a factor contributing to positive ACh test.

CONCLUSIONS

Among patients suspected for VSA, men as compared with women were more likely to have positive ACh provocation test. While current smoking and an HDL cholesterol level were associated with VSA in the entire study population, a lower HDL cholesterol level was determined as the only factor contributing to positive ACh test across genders, suggesting that HDL cholesterol plays important roles in the mechanism of VSA.

Relation Between Cancer and Vasospastic Angina

INTRODUCTION

Patients with cancer have an increased risk of cardiovascular disease including ischemic heart disease and vice versa. Anticancer drugs and radiotherapy are known to contribute to endothelial injury and vasospasm. However, the relations between vasospastic angina (VSA) and cancer or its treatment are poorly investigated.

METHODS

A total of 786 patients underwent intracoronary acetylcholine (ACh) provocation tests to diagnose VSA. The positive ACh provocation test was defined as angiographic coronary artery spasm accompanied by chest pain and/or ischemic electrocardiographic changes. Patients were divided into active cancer, a history of cancer, and no cancer according to the status of malignancy. The impact of types of cancer, anticancer drugs, and radiotherapy on VSA was evaluated.

RESULTS

Of 786 patients, 38 (4.8%) and 84 (10.7%) had active cancer and a history of cancer, respectively, and 401 (51.0%) were diagnosed as VSA. There was no significant difference in rates of positive ACh test among patients with active cancer, a history of cancer, and no cancer (39.5% vs. 57.1% vs. 50.9%, p = 0.20). Types of cancer and cancer treatment also had no impact on positive ACh provocation test.

CONCLUSIONS

In this cross-sectional observational study, we did not find an association of active and a history of cancer with the diagnosis of VSA. Anticancer treatment including chemotherapy and radiotherapy was not significantly associated with positive ACh provocation test.

Vasospastic angina and overlapping cardiac disorders in patients resuscitated from cardiac arrest

BACKGROUND

Vasospastic angina (VSA) reportedly accounts for one form of sudden cardiac arrest (SCA). Intracoronary acetylcholine (ACh) testing is useful for diagnosing VSA although invasive provocation testing after SCA is a clinical challenge. In addition, even if the ACh test is positive, any causal relationship between VSA and SCA is often unclear because patients with VSA may have other underlying cardiac disorders.

METHODS

A total of 20 patients without overt structural heart disease who had been fully resuscitated from SCA were included. All patients underwent the ACh provocation test and scrutiny such as cardiac computed tomography or magnetic resonance imaging. Patients were followed up for all-cause death or recurrent SCA including appropriate implantable cardioverter defibrillator therapy.

RESULTS

An ACh provocation test was performed 20 ± 17 days after cardiac arrest. Fifteen out of 20 (75.0%) patients had a positive ACh test and 2 (10.0%) had adverse events such as ventricular tachycardia and transient cardiogenic shock during the test. In patients with a positive ACh test, 6 of 15 (40.0%) patients had other overlapping cardiac disorders such as long QT syndrome, Brugada syndrome, cardiac sarcoidosis, myocarditis, or cardiomyopathy. Long-term prognosis was not different regardless of a positive ACh test or the presence of other cardiac disorders overlapping with VSA.

CONCLUSIONS

Three-quarters of the patients who had been resuscitated from SCA had a positive ACh test. Further examinations revealed other overlapping cardiac disorders in addition to VSA in 40% of patients with a positive ACh test.

Mental Health Status in Patients Undergoing Intracoronary Acetylcholine Provocation Test

BACKGROUND

Previous studies showed the relation of mental distress such as anxiety and depression to coronary vasoconstriction and myocardial ischemia. However, the mental health status of patients suspected to have vasospastic angina is unclear.

METHODS

A total of 99 patients underwent intracoronary acetylcholine (ACh) provocation tests for the diagnosis of vasospastic angina and mental health assessment using the 12-item General Health Questionnaire (GHQ-12) and State-Trait Anxiety Inventory Form Y (STAI Y-2). Patients with binary GHQ-12 ≥ 4 were defined as having poor mental health.

RESULTS

Median GHQ-12 and STAI Y-2 were 3 [1, 6] and 44 [36, 50]. Forty-one (41%) patients had binary GHQ-12 ≥ 4, and 48 (48%) had positive ACh provocation tests. The number of provoked vasospasms and rate of electrocardiographic change and chest pain during ACh tests were not significantly different between patients with and without GHQ-12 ≥ 4. The incidence of positive ACh provocation test was similar between the two groups (49% vs. 48%, p = 1.00). The multivariable analysis indicated that younger age, no history of percutaneous coronary intervention and no diabetes mellitus were factors associated with higher GHQ-12 and/or STAI Y-2 scores.

CONCLUSIONS

More than 40% of patients who underwent ACh provocation tests had poor mental condition. No impact of mental distress on positive ACh tests was found in this study.