Impact of high-density lipoprotein cholesterol level in patients with variant angina pectoris

Predicting the response to acetylcholine in ischemia or infarction with non-obstructive coronary arteries: The ABCD score

BACKGROUND AND AIMS

Acetylcholine (ACh) provocation testing can detect vasomotor disorders in patients with ischemia and non-obstructed coronary arteries (INOCA) or myocardial infarction and non-obstructed coronary arteries (MINOCA). We aimed to derive and validate a simple risk score to predict a positive ACh test response.

METHODS

We prospectively enrolled consecutive INOCA and MINOCA patients undergoing ACh provocation testing. Patients were split in two cohorts (derivation and validation) according to time of enrolment. The score was derived in 386 patients (derivation cohort) and then validated in 165 patients (validation cohort).

RESULTS

551 patients were enrolled, 371 (67.3%) INOCA and 180 (32.7%) MINOCA. ACh test was positive in 288 (52.3%) patients. MINOCA, myocardial bridge (MB), C-reactive protein (CRP) and dyslipidaemia were independent predictors of a positive ACh test in the derivation cohort. The ABCD (Acute presentation, Bridge, CRP, Dyslipidaemia) score was derived: 2 points were assigned to MINOCA, 3 to MB, 1 to elevated CRP and 1 to dyslipidaemia. The ABCD score accurately identified patients with a positive ACh test response with an AUC of 0.703 (CI 95% 0.652-0.754,p < 0.001) in the derivation cohort, and 0.705 (CI 95% 0.626-0.784, p < 0.001) in the validation cohort. In the whole population, an ABCD score ≥4 portended 94.3% risk of a positive ACh test and all patients with an ABCD score ≥6 presented a positive test.

CONCLUSIONS

The ABCD score could avoid the need of ACh provocation testing in patients with a high score, reducing procedural risks, time, and costs, and allowing the implementation of a tailored treatment strategy. These results are hypothesis generating and further research involving larger cohorts and multicentre trials is needed to validate and refine the ABCD score.

Clinical Characteristics and Prognosis of Patients with Vasospastic Angina Subjected to the Spasm Provocation Test and the Unavoidable Use of Nitroglycerin

Background: Multi-vessel spasm (MVS) has a prognostic impact in patients with vasospastic angina (VSA). Thus, the presence of coronary spasm in both the left coronary artery (LCA) and right coronary artery (RCA) should be assessed through the spasm provocation test (SPT). Nitroglycerin (NTG) is used to avoid SPT-related complications; however, this unavoidable use of NTG may decrease the detection of MVS. Therefore, we investigated the frequency of the unavoidable use of NTG during SPT and clarified the clinical characteristics in patients with VSA who underwent the unavoidable use of NTG during STP. Methods: A total of 141 patients with positive SPT were evaluated. A positive SPT was defined as > 90% constriction in epicardial coronary arteries in response to acetylcholine, accompanied by the usual chest symptoms and/or ischaemic ST-T changes on electrocardiography. When a coronary spasm occurred, we usually wait for the spontaneous relief of the coronary spasm. However, if a prolonged coronary spasm or unstable haemodynamics occurred, 0.3 mg NTG was administered intracoronarily to promptly relieve the coronary spasm and this was defined as the unavoidable use of NTG. Even when the unavoidable use of NTG was administered in one coronary artery, an additional SPT was performed on another coronary artery. If a coronary spasm occurred in another coronary artery, a positive SPT was diagnosed. In contrast, if a coronary spasm was not induced after the unavoidable use of NTG, the judgement was classified as undiagnosed. The patients were divided into two groups according to the unavoidable use of NTG: U-NTG (n = 42) and the final use of NTG: F-NTG (n = 99). The clinical characteristics and frequencies of MVS (≥2 major coronary arteries in which a coronary spasm was provoked) and complications (malignant arrhythmia and unstable haemodynamics requiring catecholamines) during the SPT were compared between the groups. Results: Except for smoking status, all other clinical characteristics did not differ significantly between the groups. More current smokers were observed in the U-NTG group (29%) than in the F-NTG group (12%, p = 0.02). The frequency of MVS did not vary significantly between the groups (p = 0.28), with 64% for U-NTG and 55% for F-NTG. No significant difference was found between the groups in the frequency of severe complications during SPT (p = 0.83), with 2% for U-NTG and 3% for F-NTG. In the U-NTG group, the positive induction rate of coronary spasm in another coronary artery was 40% (17/42). Conclusions: The unavoidable use of NTG occurred in ~30% of patients with VSA, most of whom were current smokers. It did not decrease the detection of MVS and potentially prevented severe complications during SPT. Therefore, the unavoidable use of NTG is acceptable during SPT. However, an additional test may need to be performed to assess the presence of MVS.

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.

Increased plasma xanthine oxidoreductase activity deteriorates coronary artery spasm

Increased reactive oxygen species (ROS) contributes to the development of endothelial dysfunction, which is involved in coronary artery spasm (CAS). Xanthine oxidoreductase (XOR) plays a pivotal role in producing both uric acid and ROS. However, the association between plasma XOR activity and CAS has not been elucidated. The aim of this study was to investigate whether plasma XOR activity is associated with CAS. We measured XOR activity in 104 patients suspected for CAS, who presented without significant coronary artery stenosis and underwent intracoronary acetylcholine provocation tests. CAS was provoked in 44 patients and they had significantly higher XOR activity as compared with those without CAS. The patients were divided into three groups based on the XOR activity. The prevalence rate of CAS was increased with increasing XOR activity. A multivariate logistic regression analysis showed that the 3rd tertile group exhibited a higher incidence of CAS as compared with the 1st tertile group [odds ratio (OR) 6.9, P = 0.001) and the 2nd tertile group (OR 3.2, P = 0.033) after adjustment for conventional CAS risk factors, respectively. The C index was significantly improved by the addition of XOR activity to the baseline model based on CAS risk factors. Furthermore, the 3rd tertile group had the highest incidence of severe spasm defined as total obstruction, flow-limiting stenosis, diffuse spasm, multivessel spasm, and/or lethal arrhythmia. This is a first report to elucidate the association of plasma XOR activity with CAS. Increased plasma XOR activity is significantly associated with CAS.

Increased circulating malondialdehyde-modified low-density lipoprotein levels in patients with ergonovine-induced coronary artery spasm

OBJECTIVE

Coronary endothelial dysfunction is thought to underlie the development of coronary artery spasms. Malondialdehyde-modified low-density lipoprotein (MDA-LDL) was suggested as a marker of endothelial damage. This study investigated the diagnostic impact of MDA-LDL on ergonovine-induced coronary spasms.

METHODS

We included 152 patients with suspected coronary spastic angina. MDA-LDL levels were measured before an ergonovine provocation test. Coronary spasm was defined as total or subtotal occlusion, compared to the relaxed state after nitroglycerin, associated with ischemic ECG changes and concurrent chest pain. Changes in vessel diameter in response to ergonovine were evaluated with quantitative coronary angiography.

RESULTS

Coronary spasms were observed in 41 patients (27%). MDA-LDL levels were significantly higher in patients with spasms compared to those without spasms (139.9 ± 45.9 U/L vs. 109.6 ± 36.6 U/L, p<0.01). Univariate logistic regression analyses indicated significant relationships between coronary spasms and MDA-LDL (per 10 U/L, odds ratio (OR): 1.20; p<0.01), high-density lipoprotein (per 10 mg/dL, OR: 0.76; p=0.03), smoking (OR: 3.04; p<0.01), and male gender (OR: 3.51; p<0.01). In the multivariate model, MDA-LDL (per 10 U/L, OR: 1.17; p<0.01) remained a significant predictor of coronary spasm. Regression analysis showed a positive correlation between MDA-LDL levels and coronary luminal diameter changes induced by ergonovine (r=0.57, p<0.01). The optimal MDA-LDL threshold for predicting coronary spasm was 121.3 U/L, identified with a receiver operating characteristic curve.

CONCLUSIONS

Increased circulating MDA-LDL levels were associated with ergonovine-induced coronary artery spasm.

Utility of the Japan arteriosclerosis longitudinal study score for identifying a high risk for vasospastic angina

OBJECTIVE

The aim of this study was to investigate whether the Japan Arteriosclerosis Longitudinal Study (JALS) score, which is calculated from the traditional atherosclerotic coronary risk, is associated with the incidence of coronary vasospasms.

METHODS

We performed vasospasm provocation tests with acetylcholine in 109 patients referred to our hospital due to suspected vasospastic angina and subsequently calculated the atherosclerotic risk score according to the JALS score. Consequently, coronary vasospasms were evoked in 51 patients. The patients were divided into three groups according to the tertile of the JALS score: 1st, <28, n=36; 2nd, 28-41, n=36, 3rd, >42, n=37. The third tertile exhibited the greatest risk for vasospasms. A multivariate logistic regression analysis revealed that the JALS score (odds ratio: 1.686, p<0.05) was independently associated with the incidence of vasospasms.

CONCLUSION

The JALS score can serve as a useful tool for evaluating patients with suspected coronary vasospasms.