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The study compared the 2-year outcomes of patients diagnosed with acute myocardial infarction (AMI) triggered by coronary artery atherosclerosis and AMI caused by coronary artery spasm. A total of 36,797 patients in the Korea AMI Registry were grouped into 2 categories-(1) AMI due to coronary artery spasm without stenotic lesion (CAS-AMI, n = 484); and (2) AMI induced by coronary artery atherosclerosis (CAA-AMI, n = 36,313). The major clinical outcomes of the 2 groups were compared over a 2-year clinical follow-up period. Major adverse cardiac events (MACE) were defined as the composite of total death, nonfatal myocardial infarction, and repeat revascularization. The incidence of MACE (7.1% vs 11.1%; p = 0.007) and repeat revascularization (0.4% vs 4.2%; p <0.001) in the CAS-AMI group were significantly lower than in the CAA-AMI group at 2 years. However, the incidence of total death and nonfatal myocardial infarction was similar in both the groups. Aborted cardiac arrest was strongly associated with 2-year mortality in the CAS-AMI group (hazard ratios 13.5, 95% confidence interval 5.34 to 34.15, p <0.001) The incidence of MACE in CAS-AMI patients was significantly lower than in the CAA-AMI group of patients up to 2 years due to the relatively lower rate of repeat revascularization in CAS-AMI patients. However, the incidence of total death or nonfatal myocardial infarction in CAS-AMI patients was not different from that of patients with CAA-AMI., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: We evaluated the effect of chronic exposure to air pollutants (APs) on coronary endothelial function and significant coronary artery spasm (CAS) as assessed by intracoronary acetylcholine (ACH) provocation test., Patients and Methods: A total of 6430 patients with typical or atypical chest pain who underwent intracoronary ACH provocation test were enrolled. We obtained data on APs from the Korean National Institute of Environmental Research (http://www.nier.go.kr/). APs are largely divided into two types: particulate matter with aerodynamic diameter of less than or equal to 10 µm in size (PM10) and gaseous pollutants such as nitrogen dioxide, sulfur dioxide, carbon monoxide, and ozone. The primary endpoint is the incidence of significant CAS and its associated parameters during ACH provocation test., Results: The incidence of CAS was positively correlated with an exposure duration of PM10, whereas nitrogen dioxide, sulfur dioxide, carbon monoxide, and ozone were shown to be unrelated to CAS. During the ACH provocation test, as PM10 increased, the frequency of CAS was increased, and the incidence of transient ST-segment elevation was also increased. There was a trend toward higher incidence of spontaneous spasm as PM10 increased. The mean exposure level of PM10 was 51.3±25.4 µg/m. The CAS risk increased by 4% when the level of PM10 increased by 20 µg/m by an adjusted Cox regression analysis., Conclusion: CAS incidence is closely related to exposure to PMs but not to gaseous pollutants. Particularly, higher exposure concentrations and longer exposure duration of PM10 increased the risk of CAS. These important findings provide a plausible mechanism that links air pollution to vasospastic angina and provide new insights into environmental factors.

Objective: We aimed to evaluate the additive benefit of trimetazidine with well-known antispasmodic agents such as calcium channel blockers and nitrate in patients with significant coronary artery spasm (CAS) as assessed by acetylcholine provocation test up to 5 years., Methods: A total 1727 patients with significant CAS were enrolled. They were divided into two groups: a trimetazidine group (trimetazidine, diltiazem, and nitrate, n = 695), and control group (diltiazem and nitrate, n = 473). After propensity score matching analysis, two matched groups (441 pairs, n = 882, C-statistic = 0.673) were generated. The individual and composite clinical end points [mortality, myocardial infarction (MI), revascularization, cerebrovascular accident (CVA), major adverse cardiac events (MACE), major adverse cardiac or cerebrovascular events (MACCE), and recurrent angina] were assessed up to 5 years for the two groups., Results: At 5 years, there were similar incidences of individual and composite hard endpoints including mortality, MI, revascularization, CVA, MACE, MACCE, and recurrent angina in the two groups., Conclusions: Additional long-term (5-year) treatment with trimetazidine in combination with diltiazem and nitrate in patients with significant CAS was not associated with improved clinical outcomes compared with combination therapy with diltiazem and nitrate only (without trimetazidine).

Background: Long-term clinical outcome data according to severity of coronary artery spasm (CAS) as assessed by an intracoronary acetylcholine provocation test are limited in series of Asian patients., Aim: To investigate 5-year clinical outcomes in patients with CAS according to CAS severity., Methods: In total, 5873 consecutive patients with insignificant coronary artery disease (<70% fixed stenosis) who underwent an acetylcholine provocation test were enrolled and divided into four groups according to CAS severity during the acetylcholine provocation test: negative, borderline positive, moderately positive and severely positive. CAS severity was assessed by quantitative coronary angiography. We investigated 5-year clinical outcomes according to CAS severity., Results: Over a follow-up period of up to 5 years, before adjustment, the severely-positive CAS group showed a significantly higher incidence of major adverse cardiac events (MACE; composite of death, myocardial infarction and de novo revascularization) (hazard ratio [HR]: 1.834, 95% confidence interval [CI]: 1.047-3.211; P=0.033), total death (HR: 3.124, 95% CI: 1.047-9.322; P=0.041), myocardial infarction (HR: 3.190, 95% CI: 1.069-9.519; P=0.037) and recurrent angina (HR: 1.762, 95% CI: 1.363-2.278; P<0.001) compared with the negative group. However, after adjustment for baseline confounders, only the incidence of recurrent angina (HR: 1.323, 95% CI: 1.014-1.726; P=0.039) was significantly higher in the severely-positive CAS group compared with the negative group., Conclusions: The severity of CAS in the positive group was not associated with an increased incidence of MACE after adjustment for covariates compared with the negative group, but the severely-positive CAS group was associated with a higher incidence of recurrent angina compared with the negative group., (Copyright © 2017 Elsevier Masson SAS. All rights reserved.)

Background and Aims: Myocardial bridge (MB) and coronary artery spasm (CAS) can induce a sustained chest pain, acute coronary syndrome (ACS) and even sudden cardiac death. The aim of this study is to evaluate the relationship between MB and CAS and its impact on long-term clinical outcomes., Methods: A total of 812 patients with MB without significant coronary artery disease (CAD), who underwent acetylcholine (ACH) provocation test, were enrolled. Significant CAS was defined as ≥70% temporary narrowing by ACH test, and MB was defined as the characteristic phasic systolic compression of the coronary artery with a decrease of more than 30% in diameter on the angiogram after intracoronary nitroglycerin infusion. To adjust baseline confounders, logistic regression analysis was performed. The primary endpoint was incidence of CAS, and secondary endpoints were major adverse cardiac events (MACE) and recurrent angina requiring repeat coronary angiography (CAG) at 5 years., Results: MB is closely implicated in a high incidence of CAS, spontaneous spasm, ischemic ECG change and chest pain during ACH provocation test. In addition, MB of various severity and reference vessel size was substantially implicated in CAS incidence, and severe MB was a strong risk factor of CAS. MB patients with CAS were shown to have a higher rate of recurrent angina compared with MB patients without CAS, up to a 5-year follow-up. However, there were no differences regarding the incidence of MACE., Conclusions: Severe MB was associated with high incidence of CAS, and MB patients with CAS were likely to have a higher incidence of recurrent angina. Intensive medical therapy and close clinical follow-up are needed for better clinical outcomes in MB patients with CAS., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background: The long-term clinical outcomes of coronary artery spasm (CAS) patients presented with acute myocardial infarction (AMI) compared to those who did not present with AMI has rarely been investigated., Methods: From November 2004 to May 2014, a total of 3360 patients who were confirmed as CAS by the acetylcholine (Ach) provocation test and without significant coronary lesion were retrospectively analyzed. AMI was an initial presentation in 34 patients [CAS-myocardial infarction (MI) group], and not in other 3326 patients (CAS group). The clinical outcomes up to 5 years were compared between the two groups., Results: Baseline characteristics and cardiovascular risk factors did not differ between the two groups, except the higher smoking rate in CAS-MI group (38.2 vs. 23.5%, P=0.046). During a mean follow-up period of 1211±583 days, the cumulative incidence of recurrent angina [hazard ratio (HR): 2.71; 95% confidence interval (CI): 1.20-6.13; P=0.016], MI (HR: 33.89; 95% CI: 8.76-131.1; P<0.001) and major adverse cardiovascular events (MACE; HR: 10.94; 95% CI: 3.83-31.22; P<0.001) were significantly higher in the CAS-MI group. After propensity score matched analysis (1 : 5 matching; n=186, C-statistic=0.834), the incidences of recurrent angina (HR; 4.68; 95% CI: 1.62-13.5; P=0.004) and MACE (HR: 12.2; 95% CI: 2.23-67.3; P=0.003) remained higher in the CAS-MI group., Conclusion: The CAS-MI group patients were associated with higher incidence of recurrent angina, MI, and MACE compared to CAS group patients. More intensive antispastic medication might be needed for these patients, and further study will be necessary to determine which treatment can improve the prognosis of CAS-MI patients.

Background and Aims: Generally, immoderate alcohol consumption is associated with variant angina and accepted as one of the risk factors for coronary artery spasm (CAS), but evidence is lacking in this regard. The aim of this study is to evaluate the impact of alcohol consumption and drinking pattern on CAS by acetylcholine (ACH) provocation test and long-term clinical outcomes., Methods: A total of 5491 patients with typical or atypical chest pain, without significant coronary artery disease, who underwent intracoronary ACH provocation test, were enrolled prospectively, and retrospectively analyzed in this study. They were divided into two groups according to their alcohol drinking status; the current alcohol (CA) drinking group (n = 1792), and non-CA group (n = 3699). To adjust for potential confounders, a propensity score matching (PSM) analysis was performed. The primary endpoint was incidence of CAS, and secondary endpoints were major adverse cardiac events (MACE) and recurrent angina requiring repeat coronary angiography (CAG) at 5 years., Results: After PSM analysis, alcohol consumption was a strong risk factor for CAS. Furthermore, excessive alcohol consumption was correlated with a higher risk for CAS. As compared with the non-CA group, the CA group showed worse angiographic and clinical findings, including higher incidence of CAS (58% vs. 62%, p = 0.016), spontaneous spasm (17% vs. 22%, p = 0.004), multi-vessel spasm (31% vs. 37%, p = 0.009), proximal epicardial spasm (39% vs. 46%, p = 0.002), ischemic electrocardiography changes such as T-inversion (0.4% vs. 1.2%, p < 0.001) and chest pain (42% vs. 46%, p = 0.047) during ACH provocation test. However, the status and pattern of alcohol drinking had no influence on long-term clinical outcomes such as MACE or recurrent angina., Conclusions: Alcohol consumption is a strong risk factor for CAS, and excessive alcohol consumption was correlated with a higher risk for CAS. Further well-designed studies are needed to confirm the results., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Background: Coronary artery spasm (CAS) and significant coronary stenosis are known to be major causes of myocardial ischemia. However, their association and the impact of insignificant coronary stenosis (ICS) on long-term clinical outcomes of CAS patients are largely unknown., Methods: A total of 2797 patients without significant coronary artery disease (CAD) who underwent the acetylcholine (ACH) provocation test between November 2004 and October 2010 were enrolled. Significant CAS was defined as having ≥70% of temporary narrowing by ACH test and ICS as having <70% of fixed stenosis on angiography. Patients were divided into two groups: ICS group (n=764) and non-ICS group (n=845). To adjust potential confounders, a propensity score matching (PSM) analysis was performed using the logistic regression model. Primary endpoint was the composite of total death, myocardial infraction (MI), de novo percutaneous coronary intervention (PCI), and cerebrovascular accidents (CVA). Secondary endpoint was the incidence of recurrent angina requiring repeat coronary angiography (CAG) at 3years., Results: After PSM analysis, two well-balanced groups (548 pairs, total=1096) were generated. The baseline clinical characteristics were similar between the two groups. During the ACH test, compared with the non-ICS group, the ICS group had smaller spastic narrowing diameter (0.69±0.35 vs. 0.73±0.37, P=0.039) and incidence of ST-segment depression (4.0% vs. 0.9%, P=0.001). The incidence of primary and secondary endpoints was similar between the two groups up to 3years., Conclusions: Although, the ICS group was expected to have more adverse long-term clinical outcomes, it was not associated with the increased incidence of major adverse clinical outcomes compared with the non-ICS group up to 3years. Longer term follow-up studies are needed., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Background and Aims: The impact of vasomotion types on long-term clinical outcomes in patients with coronary artery spasm (CAS) induced by the acetylcholine provocation test (ACH-test) remains unclear., Methods: We evaluated 4644 consecutive patients with typical resting chest pain (CP), but no angiographically significant coronary artery lesion (<50% stenosis), who underwent an ACH-test. According to their vasomotor response, patients were categorized into four types: normal vasomotion (no CP, no ischemic electrocardiographic changes, and no vasoconstriction), microvascular spasm (CP with <75% vasoconstriction but with CP relief after nitroglycerin infusion), epicardial spasm (CP with ≥75% vasoconstriction), and ACH-test inconclusive (vasoconstriction and/or electrocardiographic changes, but no CP). We investigated CP recurrence requiring follow-up angiography and major adverse cardiovascular events (MACEs) during 5 years., Results: CP recurred in 7.9% of patients and was more frequent in abnormal vasomotion types (normal vasomotion, microvascular spasm, epicardial spasm, and inconclusive type: 5.4%, 9.8%, 10.9%, and 8.2%, respectively, log-rank p = 0.009). In multivariate analysis adjusted for medication use after the ACH-test, vasomotion subtype was not an independent predictor, whereas male sex, fixed lesion on baseline angiography, and medications including calcium channel blockers (CCBs), nitrates, and statins were independent positive predictors for recurrent CP. Alcohol consumption at the initial interview was a negative predictor. MACEs were observed in 1.6%, and the incidence was similar among subtypes (p = 0.421)., Conclusions: Recurrent CP and long-term outcomes are independent of vasomotion subtypes, but long-term use of CCBs, nitrates, and statins is a significant predictor for recurrent CP., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Purpose: Calcium channel blockers diltiazem and nitrate have been used as selective coronary vasodilators for patients with significant coronary artery spasm (CAS). However, no study has compared the efficacy of diltiazem alone versus diltiazem with nitrate for long-term clinical outcomes in patients with CAS., Materials and Methods: A total of 2741 consecutive patients without significant coronary artery disease with positive CAS by acetylcholine (Ach) provocation test between November 2004 and May 2014 were enrolled. Significant CAS was defined as a narrowing of >70% by incremental intracoronary injection of 20, 50, and 100 μg of Ach into the left coronary artery. Patients were assigned to either the diltiazem group (n=842) or the dual group (diltiazem with nitrate, n=1899) at physician discretion. To adjust for potential confounders, a propensity score matching (PSM) analysis was performed using the logistic regression model. After PSM analysis, two well-balanced groups (811 pairs, n=1622, C-statistic=0.708) were generated., Results: At 5 years, there were similar incidences in primary endpoints, including mortality, myocardial infarction, revascularization, and recurrent angina requiring repeat coronary angiography between the two groups. Diltiazem alone was not an independent predictor for major adverse cardiovascular events or recurrent angina requiring repeat coronary angiography., Conclusion: Despite the expected improvement of endothelial function and the relief of CAS, the combination of diltiazem and nitrate treatment was not superior to diltiazem alone in reducing mortality and cardiovascular events up to 5 years in patients with significant CAS., Competing Interests: The authors have no financial conflicts of interest.

Background: Coronary artery spasm (CAS) is a well-known endothelial dysfunction, and a major cause of vasospastic angina (VSA). The renin-angiotensin system (RAS) is known to be closely associated with endothelial function. However, there are only a few studies that investigated the impact of RAS inhibitor on long-term clinical outcomes in VSA patients., Methods and Results: A total of 3349 patients with no significant coronary artery disease, diagnosed with CAS by acetylcholine provocation test were enrolled for this study. Significant CAS was defined as having ≥70% narrowing of the artery after incremental injections of 20, 50, and 100 μg of acetylcholine into the left coronary artery. Patients were divided into 2 groups according to whether the prescription included RAS inhibitor or not (RAS inhibitor group: n=666, non-RAS inhibitor group; n=2683). To adjust for any potential confounders that could cause bias, propensity score matching (PSM) analysis was performed using a logistic regression model. After PSM analysis, 2 matched groups (524 pairs, n=1048 patients, C-statistic=0.845) were generated and their baseline characteristics were balanced. During the 5-year clinical follow-up, the RAS inhibitor group showed a lower incidence of recurrent angina (8.7% versus 14.1%, P=0.027), total death (0.0% versus 1.3%, P=0.045), and total major adverse cardiovascular events (1.0% versus 4.1%, P=0.026) than the non-RAS inhibitor group., Conclusions: Chronic RAS inhibitor therapy was associated with lower incidence of cardiovascular events in VSA patients in the 5-year clinical follow-up., (© 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.)

Background: Coronary artery spasm (CAS) is known to be a risk factor of acute coronary syndrome and angina pectoris. However, there is no currently available data with larger study population regarding long-term clinical outcomes of CAS in real world clinical practice., Objectives: We evaluated the prevalence of CAS and the impact of CAS on 5-year clinical outcomes in a series of Asian CAS patients documented by intracoronary acetylcholine (Ach) provocation test., Methods: A total of 1413 consecutive patients without significant coronary artery disease (CAD) who underwent Ach provocation test between Nov. 2004 and Oct. 2008 were enrolled. Significant CAS was defined as >70% of narrowing by incremental intracoronary injection of 20, 50 and 100 μg. Patients were divided into two groups based on the presence of significant CAS (the non-CAS group: n=640, the CAS group; n=773). To adjust potential confounders, a propensity score matched (PSM) analysis was performed using the logistic regression model., Results: A total of 54.7% (773/1413) patients were diagnosed as CAS documented by Ach provocation test. After PSM analysis, 2 propensity-matched groups (451 pairs, n=902, C-statistic=0.677) were generated. Despite of similar incidence of individual hard endpoints including mortality, myocardial infarction and revascularization, the CAS group showed the higher trend of recurrent angina requiring follow up angiography than the non-CAS group up to 5 years (HR; 1.56, 95% C.I.; 0.99-2.46, p=0.054)., Conclusions: The prevalence of CAS was 54.7%. Although the cumulative incidence of recurrent angina requiring follow up coronary angiography seems to be increased up to 5 years in CAS patients, CAS patients was not associated with major individual and composite clinical outcomes such as mortality, MI, PCI, CVA with optimal medical therapy as compared with patients without CAS., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

Objectives: Both diabetes mellitus (DM) and coronary artery spasm (CAS) are associated with endothelial dysfunction. Thus, a higher incidence of CAS is expected in diabetic patients (pts). We evaluated the impacts of DM and the status of blood sugar control on CAS with intracoronary acetylcholine (ACh) provocation test., Methods: A total of 986 pts (106 DM vs 880 non-DM pts) with angiographically normal coronary artery received ACh provocation test. Significant CAS was defined as a transient >90% luminal narrowing with concurrent chest pain and/ or ST-segment changes. HbA1c <7% was considered a controlled blood sugar level., Results: The incidence of CAS was similar between patients with versus without DM (30.2% vs 23.5%; P=.13). Multivariable analysis showed that DM was not an independent risk factor for significant CAS (odds ratio [OR], 1.29; 95% confidence interval [CI], 0.81-2.07; P=.28). The angiographic characteristics of CAS were also similar between these two groups. Subgroup analysis regarding the impact of the status of blood sugar control on CAS showed that the incidence of CAS was similar between diabetic pts with versus without controlled blood sugar levels (35.4% vs 25.9%; P=.29). Multivariable analysis showed that the uncontrolled blood sugar level was not an independent risk factor for CAS (OR, 0.79; 95% CI, 0.29-2.13; P=.64)., Conclusions: Despite the expected endothelial dysfunction, DM and the status of blood sugar control are not associated with CAS, suggesting the existence of different mechanisms for CAS and coronary artery disease.

Purpose: High sensitive C-reactive protein (hs CRP) is well known as a strong risk factor of cardiovascular disease (CVD). The aim of this study is to evaluate the impact of elevated hs CRP on coronary artery spasm (CAS) as assessed by intracoronary acetylcholine (ACh) provocation test., Materials and Methods: A total of 1729 consecutive patients without significant CVD who underwent coronary angiography and intracoronary ACh test between November 2004 and August 2010 were analyzed. The patients were divided into five groups according to quintiles of hs CRP levels., Results: At baseline, the prevalence of elderly, hypertension, diabetes mellitus, current smoking, and lipid levels were higher in patients with higher hs CRP. During ACh test, the incidences of significant CAS, ischemic electrocardiography (EKG) change, multivessel, and diffuse CAS were higher in patients with higher hs CRP. Multivariate analysis showed that the old age (OR=1.01, CI; 1.0-1.02, p=0.0226), myocardial bridge (OR=3.34, CI; 2.16-5.17, p<0.001), and highest quintile hs CRP (OR=1.54, CI; 1.12-2.18, p=0.008) were independent predictors of ACh induced CAS. However, there was no difference in clinical outcomes up to 12 months., Conclusion: In conclusion, higher hs CRP was associated with higher incidence of CAS, worse angiographic characteristics and ischemic EKG change, but was not associated with clinical outcomes.

High-dose aspirin has been reported to aggravate coronary artery spasm (CAS). However, it is unknown whether low-dose aspirin (LDA; 100 mg) has deleterious impact on CAS. We assessed the impact of LDA on CAS induced by intracoronary acetylcholine (ACh) provocation test. A total of 2789 consecutive patients without significant coronary artery disease who underwent ACh test between November 2004 and March 2010 were enrolled. The patients were divided into two groups: the aspirin group taking LDA before ACh test (n=221) and the no aspirin group not taking aspirin (n=2568). At baseline, the prevalence of old age, diabetes mellitus, hypertension, and hyperlipidemia were higher in the aspirin group. During the ACh test, the incidence of significant CAS, ischemic chest pain, as well as severe and multivessel spasm was higher in the aspirin group. The response rate to lower ACh dose was higher in the aspirin group. Multivariate analysis showed that the previous use of LDA was an independent predictor of CAS (adjusted odds ratio, 1.6, 95% confidence interval, 1.0-2.3; p=0.031). However, it is likely that the association of LDA and CAS that we have observed is not causal but may be hypothesis generating due to significant baseline differences. Further, male gender, old age, lipid-lowering drugs, baseline spasm, and myocardial bridge were independent predictors of CAS. LDA was more frequently associated with CAS and ischemic symptoms, as well as severe and multivessel spasm, suggesting the patients who have received LDA would require more intensive medical therapies and close follow up., (Copyright © 2012 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.)

1. Coronary artery spasm (CAS) is known to be a major cause of myocardial ischaemia. Multivessel coronary spasm (MVS) in particular is likely to induce more severe and prolonged myocardial ischaemia than single vessel spasm (SVS). 2. In the present study, a total of 1082 consecutive patients without significant coronary artery disease who underwent an acetylcholine (ACh) provocation test between March 2004 and April 2009 were investigated. Patients were divided into three groups: an MVS group (n = 275), an SVS group (n = 376) and a non-CAS group (n = 431). Differences in clinical and angiographic characteristics following the ACh provocation test were evaluated between the MVS, SVS and non-CAS groups. 3. At baseline, patients in the MVS group had the highest prevalence of peripheral artery disease (PAD), hyperlipidaemia, smoking and old age, as well as the highest triglyceride levels. Calcium channel blockers were most frequently prescribed in MVS patients before the ACh test. During the ACh test, the highest prevalence of chest pain, ischaemic electrocardiogram changes, baseline spasms and diffuse and severe spasms were observed in the MVS group. The response rate to lower ACh doses that induce CAS was also higher in the MVS group. Multivariate analysis showed that the presence of PAD (odds ratio (OR) 2.0; P = 0.006) and baseline spasm (OR 1.4; P = 0.045) were independent predictors of ACh-induced MVS. 4. In conclusion, ischaemic symptoms, diffuse and severe spasm and baseline spasm were more frequently associated with MVS patients, suggesting more intensive medical therapies and close clinical follow up would be required for this patient group., (© 2011 The Authors. Clinical and Experimental Pharmacology and Physiology © 2011 Blackwell Publishing Asia Pty Ltd.)

Mean platelet volume (MPV) is an index of platelet function that reflects platelet production rate and sensitivity to activation. The relationship between MPV and coronary vasospasm has not been previously studied. In this study, we aimed to evaluate this relationship. A total of 696 patients (age 55.20 ± 12.26, male 46.4%, female 53.6%) with typical or atypical angina who underwent diagnostic coronary angiography (CAG) and an acetylcholine (Ach)-provocation test were enrolled. Each patient was assigned to either an Ach-induced coronary vasospasm group (n = 183) or a control group (n = 513). We compared MPV between the two groups. MPV and the platelet count showed a negative correlation (r = -0.289, p < 0.001). MPV was higher in the Ach-induced coronary vasospasm group than in the control group (9.03 ± 1.37 fl and 8.69 ± 1.25 fl, respectively, p = 0.002). In multivariate analysis, MPV independently predicted Ach-induced coronary vasospasm (OR = 1.188, p = 0.018). This study identified high MPV as an independent risk factor for Ach-induced coronary vasospasm.

1. Both peripheral arterial disease (PAD) and coronary artery spasm (CAS) are associated with endothelial dysfunction. Thus, a higher incidence of CAS may be expected in patients with PAD. In the present study, we evaluated the incidence and characteristics of CAS in patients with PAD. 2. A total of 78 patients with PAD and 241 age- and gender-matched patients without PAD who had chest pain with normal coronary appearance on coronary angiograms underwent intracoronary acetylcholine (ACh) provocation test. Acetylcholine was injected into the left coronary artery in incremental doses of 20, 50 and 100 microg/min. Significant CAS was defined as a transient > 70% luminal narrowing with concurrent chest pain and/or ST segment changes. 3. Patients with PAD had a significantly higher incidence of ACh-induced significant CAS than those without PAD (60.3 vs 34.0%, respectively P < 0.001), as well as chest pain and ST segment changes during the ACh provocation test. Patients with PAD were more sensitive to lower doses of ACh and had a higher incidence of multivessel spasm than those without PAD. Multivariable logistic analysis showed that age, current smoking, PAD and myocardial bridge were independent predictors of ACh-induced significant CAS. Moreover, of these factors, PAD was the strongest independent predictor (odds ratio 4.25; confidence interval 1.33-13.54; P = 0.014). 4. In patients with chest pain, the presence of arterial disease at another site should still push the clinician towards treating the chest pain as angina, even if the coronary anatomy is normal on a coronary angiogram.

The longstanding compression-relaxation effects of myocardial bridging may produce endothelial dysfunction by direct stress on the endothelium. We tested the hypothesis that myocardial bridging induces endothelial dysfunction and subsequently increases the risk of coronary spasm and investigated the symptomatic response to medication in patients with documented myocardial bridging and coronary spasm. In 81 patients with myocardial bridging (44 men; mean age 57.2 years) and 195 control patients without bridging and atherosclerotic lesions confirmed by angiography (97 men; mean age 58.4 years), spasm provocation testing was done by incremental acetylcholine infusion into the left coronary artery. Spasm was documented in 62 of 81 patients with bridging and in 31 of 195 controls (p <0.001). A focal spasm was limited to the bridging segments compared with controls (p <0.001). In conclusion, the results of this study showed that myocardial bridging increased the risk of coronary spasm by endothelial dysfunction in the bridging segment.