Nitric oxide-mediated flow-dependent dilation is impaired in coronary arteries in patients with coronary spastic angina

Association between serum level of uric acid in Japanese young patients with coronary spastic angina receiving coronary angiography

Endothelial dysfunction may trigger coronary spastic angina (CSA). However, the risk factors for CSA in young patients remain unclear. This study aimed to investigate the age-dependent role of serum uric acid levels in patients with CSA. We enrolled 423 patients who underwent an ergonovine tolerance test during coronary angiography for the CSA evaluation. We categorized the patients as (1) young (age ≤ 65 years) CSA-positive (n = 33), (2) young CSA-negative (n = 138), (3) elderly (age > 66 years) CSA-positive (n = 42), and (4) elderly CSA-negative (n = 210) groups. In the young groups, the smoker proportion (57.6 vs. 38.4%, p = 0.04) and serum uric acid levels (6.3 ± 1.4 vs. 5.4 ± 1.5 mg/dl, p = 0.006) were significantly higher in the CSA-positive compared with the CSA-negative group. Conversely, in the elderly group, the male proportion (66.6 vs. 47.1%, p = 0.02) and alcohol consumption level (40.5 vs. 21.0%, p = 0.01) were significantly higher in the CSA-positive compared with the CSA-negative group. The multivariate analysis in young groups revealed the independent association between the serum uric acid level (p = 0.02) and the presence of CSA. Our results indicate that elevated serum uric acid levels may affect CSA development in young patients.

Clinical Characteristics and Major Adverse Cardiovascular Events in Diabetic and Non-Diabetic Patients with Vasospastic Angina

Purpose

The clinical background and prognostic impact of diabetes mellitus (DM) on vasospastic angina (VSA) are unclear; thus, in this retrospective study, we investigated whether they differ based on the presence or absence of DM in patients with VSA.

Patients and Methods

We included 272 Japanese patients with VSA diagnosed by coronary angiography (CAG) and the spasm provocation test (SPT). The diagnosis of DM was determined by measuring fasting blood glucose and hemoglobin A1C and by the patient's current oral medications. On CAG, the presence of atherosclerotic lesions (20%-50%) was checked. On SPT, the coronary spasm was defined as transient coronary vasoconstriction >90% on CAG, accompanied by chest symptoms and/or ST-T changes. Focal spasm was defined as coronary spasm occurring within one segment of the American Heart Association classification on CAG. Blood and urine tests and vascular endothelial function were also evaluated when possible. A major adverse cardiovascular event (MACE), which is defined as cardiac mortality and rehospitalization due to cardiovascular illness, was the basis for determining the prognosis.

Results

There were 49 patients (18%) in the DM group and 223 (82%) in the non-DM group. No significant differences in urinary albumin levels and peripheral vascular function were between groups. On CAG, atherosclerotic lesions were observed significantly more frequently in the DM group (63% vs 46%; P = 0.028). Results of SPT showed a trend toward fewer focal spasms in the DM group (24% vs 39%; P = 0.072). No significant differences in MACE were noted between groups in the primary analysis of DM, whereas sub-analyses of focal spasms showed lower MACE-free survival in the DM group (P = 0.042).

Conclusion

The study results support the hypothesis that DM associated with VSA should be treated appropriately, especially in cases of focal spasm, which may require more attention in treatment.

Long-term prognostic factors for cardiovascular events in patients with chest pain without diabetes mellitus nor significant coronary stenosis

Chest pain is the most common symptom of coronary artery disease (CAD) and diabetes mellitus (DM) is a well-known single strongest risk factor for cardiovascular diseases. Thus, the impact of CAD nor DM on long-term clinical effects is reported widely, but the prognostic factors of non-DM patients presenting with chest pain without significant CAD are limited. A total of 1,046 patients with chest pain without DM and significant CAD who underwent coronary angiography (CAG) and acetylcholine (ACH) provocation tests were finally enrolled. Propensity score matching and multivariate Cox-proportional hazard ratio analysis were performed to adjust for baseline potential confounders. Major adverse cardiac and cerebrovascular events (MACCE) were defined as the composite of total death, myocardial infarction (MI), revascularization, stroke, and recurrent angina. This study aimed to evaluate the long-term prognostic factors for MACCE in patients with chest pain without DM and CAD up to 5 years. Coronary artery spasm (CAS) was the most common cause of chest pain. However, long-term MACCE of CAS was not worse than those of patients with chest pain without CAS when patients with CAS had subsequent optimal antianginal medication therapy. However, a recurrent chest pain remains a problem even with continuous antianginal medication therapy. Up to 5 years, the incidence of MACCE was in 7.3%, including recurrent angina 6.9%. Dyslipidemia (HR: 2.010, 95% CI 1.166-3.466, P = 0.012), mild-moderate (30-70%) coronary stenosis (HR: 2.369, 95% CI 1.118-5.018, P = 0.024), the use of aspirin (HR: 2.885, 95% CI 1.588-5.238, P < 0.001), and the use of nitrates (HR: 1.938, 95% CI 1.094-3.433, P = 0.023) were independent risk factors for MACCE. Among the patients with chest pain without DM and significant CAD, the incidence of MACE were rare, but recurrent angina was still a challenging problem who had treated with antianginal medications.

Autophagy protein 5 controls flow-dependent endothelial functions

Dysregulated autophagy is associated with cardiovascular and metabolic diseases, where impaired flow-mediated endothelial cell responses promote cardiovascular risk. The mechanism by which the autophagy machinery regulates endothelial functions is complex. We applied multi-omics approaches and in vitro and in vivo functional assays to decipher the diverse roles of autophagy in endothelial cells. We demonstrate that autophagy regulates VEGF-dependent VEGFR signaling and VEGFR-mediated and flow-mediated eNOS activation. Endothelial ATG5 deficiency in vivo results in selective loss of flow-induced vasodilation in mesenteric arteries and kidneys and increased cerebral and renal vascular resistance in vivo. We found a crucial pathophysiological role for autophagy in endothelial cells in flow-mediated outward arterial remodeling, prevention of neointima formation following wire injury, and recovery after myocardial infarction. Together, these findings unravel a fundamental role of autophagy in endothelial function, linking cell proteostasis to mechanosensing.

Diltiazem is a useful and effective medication for reversal of coronary artery spasm-induced complete atrioventricular block: A case report

Coronary artery spasm (CAS) is characterized by reversible diffuse or focal vasoconstriction, a phenomenon that plays an important role in the pathogenesis of ischemic heart disease. Fatal arrhythmias, such as ventricular tachycardia/fibrillation and complete atrioventricular block (AV-B), are very common in patients with CAS. Nondihydropyridine calcium channel blockers (CCBs) such as diltiazem were recommended as first-line medications for treating and preventing CAS episodes. However, its use remains controversial in CAS patients with AV-B as this type of CCB can also cause AV-B itself. Here, we present the use of diltiazem in a patient with complete AV-B caused by CAS. The patient's chest pain was rapidly relieved, and complete AV-B was promptly restored to sinus rhythm following the administration of intravenous diltiazem without any adverse effects. In this report, we highlight the useful and effective application of diltiazem for treating and preventing complete AV-B caused by CAS.

Relationship between Inflammation and Vasospastic Angina

Coronary artery spasm (CAS) is a dynamic coronary stenosis causing vasospastic angina (VSA). However, VSA is a potentially lethal medical condition with multiple presentations, including sudden cardiac death. Despite investigations to explore its pathogenesis, no single mechanism has been found to explain the entire process of VSA occurrence. The roles of elevated local and systemic inflammation have been increasingly recognized in VSA. Treatment strategies to decrease local and systemic inflammation deserve further investigation.

Increased plasma glutamate in non-smokers with vasospastic angina pectoris is associated with plasma cystine and antioxidant capacity

Objectives. Endothelial dysfunction caused by oxidative stress plays an important role in the development of vasospastic angina pectoris (VSAP). Glutamate causes endothelial dysfunction by generating oxidative stress, and it inhibits cystine import into endothelial cells via the cystine/glutamate antiporter (X_C^-), which leads to depletion of antioxidant glutathione. However, whether glutamate and cystine are implicated in the pathogenesis of VSAP remains unclear. We investigated plasma glutamate and cystine levels, oxidative stress markers and antioxidant capacity in non-smoker patients with VSAP to determine whether glutamate and cystine are associated with the development of VSAP. We assessed 49 non-smokers assigned to groups with (n = 27) and without (n = 22) VSAP, and also measured plasma glutamate, cystine, nitrotyrosine, reactive oxygen metabolites and biological antioxidant potential. Results. Plasma glutamate and cystine values were significantly higher in the group with, than without VSAP (59.8 ± 25.7 vs. 43.5 ± 18.7 µmol/L, p = .016 and 35.3 ± 14.2 vs. 25.2 ± 9.1 µmol/L, p = .0056, respectively). Plasma glutamate and cystine values were significantly and positively associated (r = 0.32, p = .027). Levels of the oxidative stress markers nitrotyrosine and reactive oxygen metabolites, and biological antioxidant potential of as a measure of antioxidant capacity, did not significantly differ between the two groups. However, glutamate and biological antioxidant potential values were significantly and negatively associated (r = -0.3, p = .036). Conclusion. Plasma glutamate levels were increased in patients with VSAP who did not smoke, and they were positively associated with plasma cystine and negatively associated with the biological antioxidant potential levels.

Endothelial nitric oxide synthase Asp298Glu (894G/T) gene polymorphism as a possible risk factor for the coronary slow flow phenomenon among Iranians

Background

Mounting evidence indicates an association between endothelial dysfunction and the coronary slow flow phenomenon (CSFP). In the present study, we aimed to evaluate the possible role of endothelial nitric oxide synthase (eNOS) 894G/T and interleukin-1β (IL-1β) 315C/T polymorphisms as possible risk factors for CSFP.

Methods

This prospective study enrolled patients with CSFP and individuals with normal coronary arteries. Genotypes were assessed using regular polymerase chain reaction and direct Sanger-sequencing techniques.

Results

The study population consisted of 267 individuals: 180 patients with CSFP (49 women [27.2%]) at a median age of 55 (48–62) years and 87 controls with normal coronary arteries (56 women [64.4%]) at a median age of 47 (41–58) years. The allelic distribution of eNOS 894G/T was significantly associated with CSFP (odds ratio [OR], 1.58; 95% confidence interval (CI), 1.04–2.42; P = 0.03). This polymorphism increased the risk of CSFP under the dominant model (OR 1.73; 95% CI I.02–2.95; P = 0.04). However, the allelic frequencies (1.05; 95% CI 0.68–1.59; P = 0.83) and genotypic frequencies (0.88; 95% CI 0.52–1.49; P = 0.63) of the IL-1β 315C/T polymorphism were not associated with the incidence of CSFP in the Iranian population.

Conclusions

The CSFP and control groups were statistically different regarding the eNOS 894G/T polymorphism. Our findings also demonstrated that the IL-1β 315C/T polymorphism was not a risk factor for CSFP.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-022-02736-0.

Association between 10-Year Atherosclerotic Cardiovascular Disease Risk and Vascular Endothelial Function in Patients with Vasospastic Angina

BACKGROUND

Endothelial dysfunction is a predictor of atherosclerotic cardiovascular disease (ASCVD) and plays an important role in vasospastic angina (VA).

OBJECTIVES

This study evaluated whether flow-mediated dilation (FMD) is also a good marker of 10-year ASCVD risk (10Y-ASCVDR) in patients with VA.

METHODS

Based on their clinical history and coronary artery diameter stenosis (DS), patients were retrospectively enrolled into VA (DS <50% and positive ergonovine provocation), minor coronary artery disease (mCAD, DS <30%), and significant coronary artery disease (sCAD, DS ≥50%) groups. Endothelial function was evaluated by FMD.

RESULTS

Each group contained 50 patients. The 10Y-ASCVDR was significantly higher in the sCAD group than in the VA and mCAD groups (10.86 ± 7.30, 4.71 ± 4.04, and 4.77 ± 4.30, respectively, p < 0.001). The FMD was significantly higher in the mCAD group than in the VA and sCAD groups (6.37 ± 4.25, 3.10 ± 2.23, and 3.07 ± 1.89, respectively, p < 0.001). A significant correlation was found between the FMD and 10Y-ASCVD in the mCAD group (r = -0.622, p < 0.001) and the sCAD group (r = -0.557, p < 0.001) but not in the VA group (r = -0.193, p = 0.179). After adjusting for potential confounders such as BMI, C-reactive protein, maximal coronary stenosis, and brachial-ankle pulse wave velocity, multivariate analysis showed that FMD was independently associated with 10Y-ASCVDR in all patients. However, when looking only at the VA group, FMD did not correlate independently with 10Y-ASCVDR.

CONCLUSIONS

Unlike mCAD and sCAD, we found no correlation between 10Y-ASCVDR and endothelial function in VA. Thus, our results support that FMD is not a good marker of atherosclerotic cardiovascular risk in VA.

A relationship between unrecognized anaemia and the development of type 2 diabetes mellitus in patient with cardiovascular risks

Studies on anaemia in diabetic patients are well known. However, the data regarding association of anaemia on the development of diabetes mellitus (DM) are very limited. We aimed to evaluate the association of anaemia on the development of DM and major clinical outcomes in a series of the Korean population during 5-year clinical follow-up. The patients were retrospectively enrolled using the electronic database of Korea University Guro Hospital from January 2004 to February 2013. A total of 17 515 subjects without a history of DM were analysed. The World Health Organization definition of anaemia was used. Patients were divided into the anaemia group (n = 2907 patients) and the non-anaemia group (n = 14 608 patients). The primary endpoint was the development of DM. To adjust baseline potential confounders, a propensity score matching (PSM) analysis was performed. After PSM analysis, two matched groups (2731 pairs) were generated and their baselines characteristics were balanced. During 5-year follow-up, the anaemia group had a higher incidence of type 2 DM (10.7% vs 7.7%; hazard ratio [HR], 1.356; 95% confidence interval [CI], 1.021-1.802; P = .035), and total death (2.6% vs 1.2%; HR, 2.449; 95% CI, 1.337-4.486; P = .004) compared to the non-anaemia group. In the present study, anaemia was associated with higher rate of the development of DM and mortality during 5-year clinical follow-up. A randomized trial is needed to determine whether this results can be reproducible or not for the final conclusion.

Coronary Artery Spasm: The Interplay Between Endothelial Dysfunction and Vascular Smooth Muscle Cell Hyperreactivity

Patients with angina pectoris, the cardinal symptom of myocardial ischaemia, yet without significant flow-limiting epicardial artery stenosis represent a diagnostic and therapeutic challenge. Coronary artery spasm (CAS) is an established cause for anginal chest pain in patients with angiographically unobstructed coronary arteries. CAS may occur at the epicardial level and/or in the microvasculature. Although the underlying pathophysiological mechanisms of CAS are still largely unclear, endothelial dysfunction and vascular smooth muscle cell (VSMC) hyperreactivity seem to be involved as major players, although their contribution to induce CAS is still seen as controversial. This article will look at the role and possible mechanistic interplay between an impaired endothelial and VSMC function in the pathogenesis of CAS.

Coronary Computed Tomography Angiography for the Diagnosis of Vasospastic Angina: Comparison with Invasive Coronary Angiography and Ergonovine Provocation Test

OBJECTIVE

To investigate the diagnostic validity of coronary computed tomography angiography (cCTA) in vasospastic angina (VA) and factors associated with discrepant results between invasive coronary angiography with the ergonovine provocation test (iCAG-EPT) and cCTA.

MATERIALS AND METHODS

Of the 1397 patients diagnosed with VA from 2006 to 2016, 33 patients (75 lesions) with available cCTA data from within 6 months before iCAG-EPT were included. The severity of spasm (% diameter stenosis [%DS]) on iCAG-EPT and cCTA was assessed, and the difference in %DS (Δ%DS) was calculated. Δ%DS was compared after classifying the lesions according to pre-cCTA-administered sublingual nitroglycerin (SL-NG) or beta-blockers. The lesions were further categorized with %DS ≥ 50% on iCAG-EPT or cCTA defined as a significant spasm, and the diagnostic performance of cCTA on identifying significant spasm relative to iCAG-EPT was assessed.

RESULTS

Compared to lesions without SL-NG treatment, those with SL-NG treatment showed a higher Δ%DS (39.2% vs. 22.1%, p = 0.002). However, there was no difference in Δ%DS with or without beta-blocker treatment (35.1% vs. 32.6%, p = 0.643). The significant difference in Δ%DS associated with SL-NG was more prominent in patients who were aged < 60 years, were male, had body mass index < 25 kg/m², and had no history of hypertension, diabetes, or dyslipidemia. Based on iCAG-EPT as the reference, the per-lesion-based sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of cCTA for VA diagnosis were 7.5%, 94.0%, 60.0%, 47.1%, and 48.0%, respectively.

CONCLUSION

For patients with clinically suspected VA, confirmation with iCAG-EPT needs to be considered without completely excluding the diagnosis of VA simply based on cCTA results, although further prospective studies are required for confirmation.

The association of chronic air pollutants with coronary artery spasm, vasospastic angina, and endothelial dysfunction

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.

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.

The multi-vessel and diffuse coronary spasm is a risk factor for persistent angina in patients received anti-angina medication

Coronary artery spasm (CAS) is known to be a risk factor for cardiovascular events. However, there is limited data whether the multi-vessel and diffuse spasm (MVDS) is related to more adverse clinical outcomes compared to the Non-MVDS. The aim of this study is to evaluate the impact of the MVDS on clinical outcomes during a 3-year clinical follow-up period.A total 2797 patients underwent coronary angiography (CAG) with acetylcholine (ACH) provocation test from Nov 2004 to Oct 2010 were enrolled. It is a single-center, observational, prospective, all-comers registry designed to reflect the "real world" practic. The patients were divided into the 3 groups; the negative spasm (NS) group (n = 1188), the Non-MVDS group (n = 1081), and the MVDS group (n = 528). The incidence of major adverse cardiac events (MACE) and recurrent angina was evaluated up to 3 years. To minimize confounding factors, multivariable Cox-proportional hazards regression analysis was performed.In the 3-year clinical follow-up, the incidence of total death, myocardial infarction, de novo percutaneous coronary intervention (PCI), cerebrovascular accident and MACE were similar among the 3 groups. However, recurrent angina occurred more frequently in the MVDS group than in the NS group (hazard ratio [HR], 1.96; 95% confidence interval [CI], 1.27-3.02; P = .002). Recurrence angina between the MVDS group and the Non-MVDS group was not statistically significant (HR, 1.36; 95% CI, 0.91-2.03; P = .129).In this study, although the incidence of major adverse cardiovascular events were not different regardless of spasm type, the MVDS was associated with higher incidence of recurrent chest pain requiring repeat CAG during the 3-year follow-up period, suggesting more intensive optimal medical therapy with close clinical follow up would be necessary for this particular subset of patients.

Impact of Insulin Resistance on Acetylcholine-Induced Coronary Artery Spasm in Non-Diabetic Patients

PURPOSE

Coronary artery spasm (CAS) and diabetes mellitus (DM) are implicated in endothelial dysfunction, and insulin resistance (IR) is a major etiological cause of type 2 DM. However, the association between CAS and IR in non-diabetic individuals has not been elucidated. The aim of the present study was to evaluate the impact of IR on CAS in patients without DM.

MATERIALS AND METHODS

A total of 330 eligible patients without DM and coronary artery disease who underwent acetylcholine (Ach) provocation test were enrolled in this study. Inclusion criteria included both hemoglobin A1c <6.0% and fasting glucose level <110 mg/dL without type 2 DM. Patients were divided into quartile groups according the level of homeostasis model assessment of insulin resistance (HOMA-IR): 1Q (n=82; HOMA-IR<1.35), 2Q (n=82; 1.35≤HOMA-IR<1.93), 3Q (n=83; 1.93≤HOMA-IR< 2.73), and 4Q (n=83; HOMA-IR≥2.73).

RESULTS

In the present study, the higher HOMA-IR group (3Q and 4Q) was older and had higher body mass index, fasting blood glucose, serum insulin, hemoglobin A1c, total cholesterol, and triglyceride levels than the lower HOMA-IR group (1Q). Also, poor IR (3Q and 4Q) was considerably associated with frequent CAS. Compared with Q1, the hazard ratios for Q3 and Q4 were 3.55 (95% CI: 1.79-7.03, p<0.001) and 2.12 (95% CI: 1.07-4.21, p=0.031), respectively, after adjustment of baseline risk confounders. Also, diffuse spasm and accompanying chest pain during Ach test were more strongly associated with IR patients with CAS.

CONCLUSION

HOMA-IR was significantly negatively correlated with reference diameter measured after nitroglycerin and significantly positively correlated with diffuse spasm and chest pain.

Endothelial dysfunction as predictor of angina recurrence after successful percutaneous coronary intervention using second generation drug eluting stents

Background The role of endothelial dysfunction in predicting angina recurrence after percutaneous coronary intervention is unknown. Design We assessed the role of peripheral endothelial dysfunction measured by reactive-hyperaemia peripheral-artery tonometry (RH-PAT) in predicting recurrence of angina after percutaneous coronary intervention. Methods We enrolled consecutive patients undergoing percutaneous coronary intervention with second-generation drug-eluting stents. RH-PAT was measured at discharge. The endpoint was repeated coronary angiography for angina recurrence and/or evidence of myocardial ischaemia at follow-up. Patients with in-stent restenosis and/or significant de novo stenosis were defined as having angina with obstructed coronary arteries (AOCA); all other patients as having angina with non-obstructed coronary arteries (ANOCA). Results Among 100 patients (mean age 66.7 ± 10.4 years, 80 (80.0%) male, median follow-up 16 (3-20) months), AOCA occurred in 14 patients (14%), ANOCA in nine patients (9%). Repeated coronary angiography occurred more frequently among patients in the lower RH-PAT index tertile compared with middle and upper tertiles (14 (41.2%) vs. 6 (18.2%) vs. 3 (9.1%), p = 0.006, respectively). ANOCA was more frequent in the lower RH-PAT index tertile compared with middle and upper tertiles. In the multivariate regression analysis, the RH-PAT index only predicted angina recurrence. The receiver operating characteristic curve of the RH-PAT index to predict the angina recurrence demonstrated an area under the curve of 0.79 (95% confidence interval: 0.69-0.89; p < 0.001), with a cut-off value of 1.705, having sensitivity 74% and specificity 70%. Conclusions Non-invasive assessment of peripheral endothelial dysfunction using RH-PAT might help in the prediction of recurrent angina after percutaneous coronary intervention, thus identifying patients who may need more intense pharmacological treatment and risk factor control.

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.

Impact of Cigarette Smoking: a 3-Year Clinical Outcome of Vasospastic Angina Patients

Background and Objectives

Cigarette smoking is a risk significant factor in coronary artery disease (CAD) and vasospastic angina (VSA). However, it is largely unknown whether smoking adds to any long-term clinical risk in VSA patients.

Subjects and Methods

A total of 2797 patients without significant CAD underwent acetylcholine (Ach) provocation test between November 2004 and October 2010. Patients were divided into three groups, based on the presence of coronary artery spasm (CAS) and smoking habits (non-CAS group: n=1188, non-smoking CAS group: n=1214, smoking CAS group: n=395). All CAS patients were prescribed with anti-anginal medications for at least 6 months. The incidence of major clinical outcomes and recurrent angina of these groups were compared up to 3 years.

Results

There were considerable differences in the baseline clinical and angiographic characteristics among the three groups, but there was no difference in the endpoints among the three groups (including individual and composite hard endpoints) such as death, myocardial infarction, de novo percutaneous coronary intervention, cerebrovascular accident, and major adverse cardiac events. However, there was a higher incidence of recurrent angina in both the non-smoking CAS group and smoking CAS group, as compared to the non-CAS group. In multivariable adjusted Cox-proportional hazards regression analysis, smoking CAS group exhibited a higher incidence of recurrent angina compared with the non-CAS group (hazard ratio [HR]; 2.46, 95% confidence interval [CI]; 1.46-4.14, p=0.001) and non-smoking CAS group (HR; 1.76, 95% CI; 1.08-2.87, p=0.021).

Conclusion

Cigarette smoking CAS group exhibited higher incidence of recurrent angina during the 3-year clinical follow-up compared with both the non-CAS group and non-smoking CAS group. Quitting of smoking, paired with intensive medical therapy and close clinical follow-up, can help to prevent recurrent angina.

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.

Coronary artery spasm related to thiol oxidation and senescence marker protein-30 in aging

BACKGROUND

Senescence marker protein-30 (SMP30) decreases with aging, and SMP30 knockout (KO) mice show a short life with increased oxidant stress.

AIMS

We assessed the effect of oxidant stress with SMP30 deficiency in coronary artery spasm and clarify its underlying mechanisms.

RESULTS

We measured vascular responses to acetylcholine (ACh) and sodium nitroprusside (SNP) of isolated coronary arteries from SMP30 KO and wild-type (WT) mice. In SMP30 KO mice, ACh-induced vasoconstriction occurred, which was changed to vasodilation by dithiothreitol (DTT), a thiol-reducing agent. However, Nω-nitro-L-arginine-methyl ester, nitric oxide (NO) synthase inhibitor, or tetrahydrobiopterin did not change the ACh response. In isolated coronary arteries of WT mice, ACh-induced vasodilation occurred. Inhibition of glutathione reductase by 1, 3-bis(2-chloroethyl)-1-nitrosourea decreased ACh-induced vasodilation (n=10, p<0.01), which was restored by DTT. To evaluate the thiol oxidation, we measured the fluorescence of monochlorobimane (MCB) in coronary arteries, which covalently labels the total. The fluorescence level to MCB decreased in SMP30 KO mice, but with DTT treatment restored to a level comparable to that of WT mice. The reduced glutathione and total thiol levels were also low in the aorta of SMP30 KO mice compared with those of WT mice. Administration of ACh into the aortic sinus in vivo of SMP30 KO mice induced coronary artery spasm.

INNOVATION

The thiol redox state is a key regulator of endothelial NO synthase activity, and thiol oxidation was associated with endothelial dysfunction in the SMP30 deficiency model.

CONCLUSION

These results suggest that chronic thiol oxidation by oxidant stress is a trigger of coronary artery spasm, resulting in impaired endothelium-dependent vasodilation.

Higher serum uric acid and lipoprotein(a) are correlated with coronary spasm

It has been reported that a major cause of coronary vasospastic angina (VSA) is endothelial dysfunction of the coronary artery. On the other hand, some studies showed that serum uric acid and lipoprotein(a) are correlated with endothelial dysfunction. Thus, we examined whether uric acid and lipoprotein(a), are correlated with VSA. Four hundred forty-one patients with suspected VSA who underwent a coronary angiogram with acetylcholine provocation (ACh test) during an 8-year period were enrolled. We divided them into a VSA group, who showed coronary spasm by the ACh test, and an atypical chest pain (ACP) group, who showed negative ACh test. We compared serum markers between the two groups, including low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, high-sensitivity C-reactive protein (hs-CRP), lipoprotein(a), fibrinogen, total plasminogen activator inhibitor-1, and uric acid. Uric acid, hs-CRP, and lipoprotein(a) were significantly higher in the VSA group than in the ACP group (all P < 0.05) while there were no significant differences in the other parameters. Multivariate analyses identified uric acid and lipoprotein(a) as significant independent markers for VSA. Uric acid and lipoprotein(a) are correlated with VSA, and medical intervention to decrease uric acid and lipoprotein(a) might be effective in controlling VSA.

Evaluation of coronary microvascular function in patients with vasospastic angina

AIM: To investigate endothelium-dependent and -independent coronary microvascular functions in patients with vasospastic angina (VSA).

METHODS: Thirty-six patients with VSA (30 men and 6 women; mean age, 58 years) were enrolled in this study. VSA was defined as ≥ 90% narrowing of the epicardial coronary arteries on angiography performed during a spasm provocation test, presence of chest pain, and/or ST-segment deviation on an electrocardiogram (ECG). Patients (n = 36) with negative spasm provocation test results and those matched for age and sex were enrolled as a control group (nonVSA group). Low-dose acetylcholine (ACh; 3 μg/min) was infused into the left coronary ostium for 2 min during the spasm provocation test. Following the spasm provocation test, nitroglycerin (0.2 mg) was administered intracoronally. Coronary blood flow (was calculated from quantitative angiography and Doppler flow velocity measurements, and the coronary flow reserve was calculated as the ratio of coronary flow velocity after injection of adenosine triphosphate (20 μg) to the baseline value. Changes in the coronary artery diameter in response to ACh and nitroglycerin infusion were expressed as percentage changes from baseline measurements.

RESULTS: Body mass index was significantly lower in the VSA group than in the nonVSA group. The frequency of conventional coronary risk factors and the rate of statin use were similar between the 2 groups. The left ventricular ejection fraction as evaluated by echocardiography was similar between the 2 groups. The duration of angina was 9 ± 2 mo. The results of blood chemistry analysis were similar between the 2 groups. Low-dose ACh did not cause coronary spasms. The change in coronary artery diameter in response to ACh was lower in the VSA group (-1.4% ± 9.3%) than in the nonVSA group (3.1% ± 6.5%, P < 0.05), whereas nitroglycerin-induced coronary artery dilatation and coronary blood flow increase in response to ACh or coronary flow reserve did not differ significantly between the 2 groups.

CONCLUSION: These findings suggest that microvascular coronary function may be preserved despite endothelial dysfunction of the epicardial coronary arteries in patients with VSA.

Microvascular coronary artery spasm presents distinctive clinical features with endothelial dysfunction as nonobstructive coronary artery disease

Background

Angina without significant stenosis, or nonobstructive coronary artery disease, attracts clinical attention. Microvascular coronary artery spasm (microvascular CAS) can cause nonobstructive coronary artery disease. We investigated the clinical features of microvascular CAS and the therapeutic efficacy of calcium channel blockers.

Methods and Results

Three hundred seventy consecutive, stable patients with suspected angina presenting nonobstructive coronary arteries (<50% diameter) in coronary angiography were investigated with the intracoronary acetylcholine provocation test, with simultaneous measurements of transcardiac lactate production and of changes in the quantitative coronary blood flow. We diagnosed microvascular CAS according to lactate production and a decrease in coronary blood flow without epicardial vasospasm during the acetylcholine provocation test. We prospectively followed up the patients with calcium channel blockers for microvascular coronary artery disease. We identified 50 patients with microvascular CAS who demonstrated significant impairment of the endothelium-dependent vascular response, which was assessed by coronary blood flow during the acetylcholine provocation test. Administration of isosorbide dinitrate normalized the abnormal coronary flow pattern in the patients with microvascular CAS. Multivariate logistic regression analysis indicated that female sex, a lower body mass index, minor–borderline ischemic electrocardiogram findings at rest, limited–baseline diastolic-to-systolic velocity ratio, and attenuated adenosine triphosphate–induced coronary flow reserve were independently correlated with the presence of microvascular CAS. Receiver-operating characteristics curve analysis revealed that the aforementioned 5-variable model showed good correlation with the presence of microvascular CAS (area under the curve: 0.820). No patients with microvascular CAS treated with calcium channel blockers developed cardiovascular events over 47.8±27.5 months.

Conclusions

Microvascular CAS causes distinctive clinical features and endothelial dysfunction that are important to recognize as nonobstructive coronary artery disease so that optimal care with calcium channel blockers can be provided.

Clinical Trial Registration

URL: www.umin.ac.jp/ctr. Unique identifier: UMIN000003839.

Chest pain with ST-T changes on electrocardiogram and localized stenosis on coronary angiography could be a coronary vasospasm

Coronary vasospasm is characterized by chest pain at rest with ST-T changes on electro cardiogram and coronary angiography showing virtually normal coronaries. The definitive diagnosis requires the stimulation of coronary vasospasm using provocative agents, which can be life threatening. We present a case where localized stenosis of proximal left anterior descending artery was observed on the coronary angiography, which disappeared on subsequent views, and hence, coronary stenting was deferred and patient responded well to medical management alone.

Impairment of the extrusion transporter for asymmetric dimethyl-L-arginine: a novel mechanism underlying vasospastic angina

A 37-year old male patient presented with frequent angina attacks (up to 40/day) largely resistant to classical vasodilator therapy. The patient showed severe coronary and peripheral endothelial dysfunction, increased platelet aggregation and increased platelet-derived superoxide production. The endothelial nitric oxide synthase (eNOS)-inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME) reduced superoxide formation in platelets identifying "uncoupled" eNOS as a superoxide source. Oral L-arginine normalized coronary and peripheral endothelial dysfunction and reduced platelet aggregation and eNOS-derived superoxide production. Plasma concentrations of the endogenous NOS inhibitor asymmetric dimethyl-L-arginine (ADMA), representing an independent risk factor for cardiovascular disease, were normal in the patient. However, immediately after oral administration of cationic amino acid (CAA), plasma ADMA levels rose markedly, demonstrating increased ADMA efflux from intracellular stores. ADMA efflux from mononuclear cells of the patient was accelerated by CAA, but not neutral amino acids (NAA) demonstrating impairment of y(+)LAT (whose expression was found reduced in these cells). These data suggest that impairment of y(+)LAT may cause intracellular (endothelial) ADMA accumulation leading to systemic endothelial dysfunction. This may represent a novel mechanism underlying vasospastic angina and vascular dysfunction in general. Moreover, these new findings contribute to the understanding of the l-arginine paradox, the improvement of eNOS activity by oral L-arginine despite sufficient cellular l-arginine levels to ensure proper function of this enzyme.

Chest pain with ST-T changes on electrocardiogram and localized stenosis on coronary angiography could be a coronary vasospasm

Coronary vasospasm is characterized by chest pain at rest with ST-T changes on electro cardiogram and coronary angiography showing virtually normal coronaries. The definitive diagnosis requires the stimulation of coronary vasospasm using provocative agents, which can be life threatening. We present a case where localized stenosis of proximal left anterior descending artery was observed on the coronary angiography, which disappeared on subsequent views, and hence, coronary stenting was deferred and patient responded well to medical management alone.

Ischemic electrocardiographic changes and elevated troponin from severe heatstroke in an adolescent

BACKGROUND

Heatstroke can result in significant diffuse tissue derangement, which can result in multiple organ system dysfunction. The heart can equally be affected and ischemia and infarction may occur.

OBJECTIVE

This study aimed to present the potential complications from heatstroke to the myocardium.

CASE

A case of a 15-year-old adolescent boy who collapsed after playing football in a hot summer day was found to be hyperthermic and poorly perfused. He had ischemic electrocardiographic changes and elevated cardiac enzymes but with normal coronary arteries.

CONCLUSIONS

Heatstroke can lead to morbidity and mortality. Tissue damage during heatstroke is believed to result from uncoupling during oxidative phosphorylation. It is important to realize that heart damage can occur from heatstroke and that appropriate diagnostic and therapeutic measures are required for a good outcome.

Variant angina and coronary artery spasm: the clinical spectrum, pathophysiology, and management

Variant angina is a form of angina pectoris that shows transient ST-segment elevation on electrocardiogram during an attack of chest pain. Ischemic episodes of variant angina show circadian variation and often occur at rest from midnight to early morning. Ischemic episodes also occur during mild exercise in the early morning. However, they are not usually induced by strenuous exercise in the afternoon. Other important clinical features of variant angina include the high frequency of asymptomatic ischemic episodes and the syncope that sometimes occur during the ischemic episodes. Syncope is due to severe arrhythmias, including ventricular tachycardia, ventricular fibrillation, and high-degree atrioventricular block. Coronary artery spasm is the mechanism of ischemic episodes in variant angina. The incidence of coronary artery spasm shows a racial difference and is higher in Japanese than in Caucasians. Coronary arteriograms are normal or near-normal in most Japanese patients with variant angina. Deficient basal release of nitric oxide (NO) due to endothelial dysfunction, and enhanced vascular smooth muscle contractility with the involvement of the Rho/Rho-kinase pathway are reported to play important roles in the pathogenesis of coronary artery spasm. Other precipitating factors of coronary artery spasm include imbalance in autonomic nervous activity, increased oxidative stress, chronic low-grade inflammation, magnesium deficiency, and genetic susceptibility. The genetic risk factors associated with coronary artery spasm include gene polymorphisms of endothelial NO synthase (NOS), paraoxonase, and other genes. Calcium channel blockers are extremely effective in preventing coronary spasm. The long-acting nitrate, nicorandil, and Rho-kinase inhibitor are also useful for inhibiting coronary artery spasm. Because variant angina can lead to acute myocardial infarction, fatal arrhythmias, and sudden death, early treatment is important. The prognosis of patients with variant angina is favorable, if early complications can be overcome. However, because coronary artery spasm cannot be suppressed in some patients, even with multiple medications, medications to suppress intractable coronary artery spasm must be developed.

Disruption of coronary vasomotor function: the coronary spasm syndrome

Abnormal coronary vasoconstriction, or coronary spasm, can be the result of several factors, including local and neuroendocrine aberrations. It can manifest clinically as a coronary syndrome and plays an important role in the genesis of myocardial ischemia. Over the past half century, coronary angiography allowed the in vivo demonstration of spasm in patients who fit the initial clinical description of the condition as reported by Prinzmetal et al. Several clinical, basic, and more recently, genetic studies have provided insight into the pathogenesis, manifestations, and therapy of this condition. It is not uncommonly encountered in patients with coronary syndromes and absence of clearly pathologic lesions on angiography. Provocation tests utilizing pharmacologic and nonpharmacologic stimuli combined with imaging (echocardiography or coronary angiography) can help make the correct diagnosis. The use of calcium channel blockers and long-acting nitrates is currently considered standard of care and the overall prognosis appears to be good. The recent discovery of genetic abnormalities predisposing to abnormal spasm of the coronaries has stimulated interest in the development of targeted therapies for the management of this condition.

Interaction between cigarette smoking and high-sensitivity C-reactive protein in the development of coronary vasospasm in patients without hemodynamically significant coronary artery disease

BACKGROUND

Interaction between 2 major risk factors, cigarette smoking and high-sensitivity C-reactive protein (hs-CRP), has not been evaluated in patients with coronary vasospasm (CV) without hemodynamically significant coronary artery disease.

METHODS

From 1999 to 2005, patients undergoing diagnostic coronary angiography with or without proven CV and without coronary stenosis >50% were evaluated. A total of 621 subjects (335 and 286 with and without CV, respectively) were enrolled in the study. The levels of hs-CRP, measured immediately before coronary angiography, were examined in a subset of 314 patients.

RESULTS

Subjects with CV were likely to be older, men, current smokers, and have high hs-CRP levels. The most significant factors for CV were smoking and hs-CRP. In the nonsmoker group, elevated risk of developing CV was only demonstrated in patients with the highest hs-CRP tertile (>5.01 mg/L, P = 0.012). In the smoker group, however, a positively monotonic trend of association was demonstrated between hs-CRP tertile and CV risk, with multivariate-adjusted odds ratios of 1.11, 3.09 (P = 0.012), and 4.12 by the hs-CRP tertiles, suggesting that smokers developed CV at a lower hs-CRP level than nonsmokers and there was a positive interaction between smoking and hs-CRP.

CONCLUSIONS

The smokers developed CV at a lower hs-CRP level compared with the nonsmokers. A positive interaction between smoking and hs-CRP was demonstrated for this disease in our study population.

Novel pathway of endothelin-1 and reactive oxygen species in coronary vasospasm with endothelial dysfunction

The role of endothelial dysfunction in coronary vasospasm is controversial. We hypothesized that reactive oxygen species (ROS) and endothelin-1 (ET-1) are plausible candidates as the mediator of vasospasm is linked to endothelial dysfunction. In a pig model with repetitive endothelial injury in coronary arteries, intracoronary administration of serotonin induced a vasospasm at the endothelial injury site. The level of endothelin-converting enzyme was upregulated at that site where, upon exposure to serotonin, there were also increases in p47(phox), ROS, and ET-1 fluorescence intensities, and myosin light chain phosphorylation and RhoA activation were detected. The nicotinamide adenine dinucleotide phosphate oxidase inhibitor, apocynin, had the effect of extinguishing not only ROS but also the appearance of ET-1. The chronic blockade of endothelin type-A receptor prevented a serotonin-triggered vasospasm along with the inhibition of ROS generation and myosin light chain phosphorylation. Under the coronary artery endothelial dysfunction, ET-1 is essential for an ROS-dependent coronary vasospasm. Our findings suggest that endothelial dysfunction plays a critical role in clinically defined human Prinzmetal angina.

Combination of variant and microvascular angina

Prinzmetal's variant angina (VA) and cardiac syndrome X (CSX) are two distinct, usually easily recognizable, forms of angina syndromes, caused by epicardial spasm, usually responsible for transient transmural myocardial ischemia at rest and by coronary microvascular dysfunction (CMVD), usually responsible for effort induced subendocardial ischemia, respectively. In this article we report clinical evidence in three patients of the simultaneous occurrence of angina episodes typical of both VA and CSX, suggesting that common pathogenetic factors may be responsible for clinical manifestations both of functional macrovascular and microvascular coronary artery abnormalities in some angina patients.

Characteristic changes in coronary artery at the early hyperglycaemic stage in a rat type 2 diabetes model and the effects of pravastatin

BACKGROUND AND PURPOSE

Diabetes is a risk factor for the development of coronary artery disease but it is not known whether the functions of endothelium-derived nitric oxide (NO) and endothelium-derived hyperpolarizing factor (EDHF) in coronary arteries are altered in the early stage of diabetes. Such alterations and the effects of pravastatin were examined in left anterior descending coronary arteries (LAD) from Otsuka Long-Evans Tokushima Fatty (OLETF) rats (type 2 diabetes model) at the early hyperglycaemic stage [vs. non-diabetic Long-Evans Tokushima Otsuka (LETO) rats].

EXPERIMENTAL APPROACH

Isometric tension, membrane potential and superoxide production were measured, as were protein expression of NAD(P)H oxidase components and endothelial NO synthase (eNOS).

KEY RESULTS

Superoxide production and the protein expressions of both the nicotinamide adenine dinucleotide (phosphate) [NAD(P)H] oxidase components and eNOS were increased in OLETF rats. These changes were normalized by pravastatin administration. Not only acetylcholine (ACh)-induced endothelial NO production but also functions of endothelium-derived NO [from (i) the absolute tension induced by epithio-thromboxane A(2) (STA(2)) or high K(+); (ii) enhancement of the STA(2)-contraction by a nitric oxide synthase (NOS) inhibitor; and (iii) the ACh-induced endothelium-dependent relaxation of high K(+)-induced contraction] or EDHF [from (iv) ACh-induced endothelium-dependent smooth muscle cell hyperpolarization and relaxation in the presence of a NOS inhibitor] were similar between LETO and OLETF rats [whether or not the latter were pravastatin-treated or -untreated].

CONCLUSIONS AND IMPLICATIONS

Under conditions of increased vascular superoxide production, endothelial function is retained in LAD in OLETF rats at the early hyperglycaemic stage, partly due to enhanced endothelial NOS protein expression. Inhibition of superoxide production may contribute to the beneficial vascular effects of pravastatin.

Impact of hypertension on coronary artery spasm as assessed with intracoronary acetylcholine provocation test

Both hypertension and coronary artery spasm (CAS) are associated with endothelial dysfunction. Thus, a higher incidence of CAS is expected in hypertensive patients. We evaluated the impact of hypertension on CAS with intracoronary acetylcholine (ACh) provocation test. A total of 986 patients (685 hypertensive patients vs 301 normotensive patients) who underwent coronary angiography with ACh provocation test were enrolled. ACh was injected into the left coronary artery in incremental doses of 20, 50 and 100 microg min(-1). Significant CAS was defined as a transient >70% luminal narrowing with concurrent chest pain and/or ST-segment changes. Although the incidences of significant ACh-induced CAS were similar between hypertensive and normotensive patients (35.8 vs 39.2%, P=0.303), multivariate logistic analysis showed that hypertension was negatively associated with ACh-induced CAS (odds ratio: 0.70, 95% confidence interval: 0.51-0.94, P=0.020). The angiographic characteristics of ACh-induced CAS were similar between these two groups. Subgroup analysis regarding the impact of the status of blood pressure control on CAS showed that hypertensive patients with controlled blood pressure had a significantly higher incidence of CAS than those with uncontrolled blood pressure (45.2 vs 27.9%, P<0.001), and that uncontrolled blood pressure was negatively associated with ACh-induced CAS (odds ratio: 0.56, 95% confidence interval: 0.40-0.79, P=0.001). In conclusion, despite the expected endothelial dysfunction, hypertension and uncontrolled blood pressure are negatively associated with CAS, suggesting that the mechanisms and risk factors of CAS may be significantly different from those of coronary artery disease.