Search

Background: Lipoprotein(a) [Lp(a)] is an independent risk factor for atherosclerotic vascular disease. However, there are limited data regarding the impact of Lp(a) levels on the incidence and severity of endothelium-dependent coronary vasomotor response., Patients and Methods: A total of 2416 patients without significant coronary artery lesion (<50% stenosis) by coronary angiography and underwent acetylcholine (ACh) provocation test were enrolled and categorized according to their serum Lp(a) level into four quartile groups: less than 6.70, 6.70-13.30, 13.30-26.27, and more than 26.27 mg/dl. The aim of this study is to estimate the incidence and severity of endothelium-dependent positive ACh provocation test in each group; moreover, to access the incidence of major adverse cardiovascular events, the composite of total death, myocardial infarction, and de novo percutaneous coronary intervention were compared between the four groups up to 5 years., Results: The group with higher Lp(a) had a higher incidence of coronary heart disease, myocardial infarction, and peripheral arterial disease history. However, there was no difference among the four groups as regards the incidence of positive ACh provocation test, spasm severity, spasm extent, and location. However, at up to 5 years of clinical follow-up, the higher-Lp(a) group showed higher total death, de novo percutaneous coronary intervention, recurrent angina, and total major adverse cardiovascular events compared with the lower-Lp(a) groups., Conclusion: In our study, there was no relationship between the elevated Lp(a) level and the vasospastic response to the intracoronary ACh provocation test; however, higher Lp(a) levels were associated with poor clinical outcomes up to 5 years.

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 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.)

There is limited long-term comparative clinical outcome data concerning angiography- versus intravascular ultrasound (IVUS)-guided percutaneous coronary intervention (PCI) in non-complex left main coronary artery (LMCA) disease treated with the single stenting technique in the drug-eluting stent (DES) era.The aim of this study was to investigate whether angiography-guided stenting is comparable to IVUS-guided stenting during 3-year clinical follow-up periods in patients with non-complex LM disease treated with the single stenting technique.A total of 196 patients treated with either angiography-guided (n = 74) or IVUS-guided (n = 122) PCI were included. The primary outcome was the occurrence of major adverse cardiac events (MACE) defined as total death, non-fatal myocardial infarction (MI), target lesion revascularization (TLR), target vessel revascularization (TVR), and non-target vessel revascularization (Non-TVR). To adjust for any potential confounders, propensity score (PS) adjusted analysis was performed.During 3-year follow-up, the PS adjusted Cox-proportional hazard ratio (HR) was not significantly different between the two groups for total death, cardiac death, and MI. Also, TLR and the combined rates of TVR and non-TVR were not significantly different. Finally, MACE was not significantly different between the two groups (HR: 0.63, 95% Confidence interval (CI): 0.33-1.17; P = 0.149).Angiography-guided PCI for non-complex LMCA diseases treated with the single stenting technique showed comparable results compared with IVUS-guided PCI in reducing clinical events during 3-year clinical follow-up in the DES era. Although IVUS guided PCI is the ideal strategy, angiography-guided PCI can be an option for LMCA PCI in some selected cases.

Background: The impact of percutaneous coronary intervention (PCI) on chronic total occlusion in patients with well-developed collaterals is not clear., Methods and Results: A total of 640 chronic total occlusion patients with collateral flow grade ≥2 were divided into 2 groups; chronic total occlusion patients either treated with PCI (the PCI group; n=305) or optimal medical therapy (the optimal medical therapy group; n=335). To adjust for potential confounders, a propensity score matching analysis was performed. Major clinical outcomes were compared between the 2 groups up to 5 years. In the entire population, the PCI group had a lower hazard of myocardial infarction (hazard ratio [HR], 0.177; P =0.039; 95% confidence interval [CI], 0.03-0.91) and the composite of total death or myocardial infarction (HR, 0.298; P =0.017; 95% CI, 0.11-0.80); however, it showed higher hazard of target lesion revascularization (HR, 3.942; P =0.003; 95% CI, 1.58-9.81) and target vessel revascularization (HR, 4.218; P =0.001; 95% CI, 1.85-9.60). After propensity score matching, a total of 158 matched pairs were generated. Although the PCI group showed a higher hazard of target lesion revascularization (HR, 2.868; P =0.027; 95% CI, 1.13-7.31) and target vessel revascularization (HR=2.62; P =0.022; 95% CI, 1.15-5.97), it still exhibited a lower incidence of the composite of total death or myocardial infarction (HR, 0.263; P =0.017; 95% CI, 0.087-0.790). The mean ejection fraction was improved from 47.8% to 51.6% ( P <0.001) after PCI., Conclusions: In our study, successful revascularization by PCI for chronic total occlusion lesions with well-developed collaterals was associated with lower incidence of death and myocardial infarction, improved left ventricular function, but increased repeat revascularization rate., (© 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.)

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.)

Objective: The difference in the usefulness of routine angiographic follow-up (RAF) and clinical follow-up (CF) after a percutaneous coronary intervention (PCI) in multivessel coronary artery disease (MVD) patients has not been well clarified as yet., Patients and Methods: A total of 642 consecutive MVD patients who underwent PCI with drug-eluting stents (DES) were enrolled. RAF was performed at 6-9 months after the index PCI (n=374) and others were medically managed and clinically followed (n=268). Patients who experienced clinical events including death, myocardial infarction (MI), and ischemia-driven PCI before 1 year were excluded. To adjust for any potential confounders, a propensity scorematched analysis was carried out using the logistic regression model and two propensity-matched groups (193 pairs, n=386, C-statistic=0.744) were generated. Cumulative clinical outcomes up to 3 years were compared between the RAF group and the CF group., Results: During the 3-year follow-up period, the cumulative incidence of revascularization [target lesion revascularization: odds ratio (OR), 4.21; 95% confidence interval (CI), 1.67-10.6; P=0.001) and target vessel revascularization (TVR: OR, 4.69; 95% CI, 2.00-11.0; P<0.001, target vessel revascularization: OR, 4.69; 95% CI, 2.00-1011.0; P<0.001] and major adverse cardiovascular events (composite of death, repeat PCI and MI: OR, 2.96; 95% CI, 1.62-105.42, P<0.001) were significantly higher in the RAF group compared with the CF group. However, the 3-year incidence of death (OR, 1.41; 95% CI, 0.44-104.53; P=0.558) or MI (OR, 2.58; 95% CI, 0.79-108.37; P=0.102) was not different between the two groups. In MVD patients treated with second-generation DESs, the incidence of repeat revascularization (target lesion revascularization and target vessel revascularization) was not different between the two groups., Conclusion: Conclusion RAF following index PCI with DES in multivessel CAD patients was associated with increased incidence of revascularization and major adverse cardiovascular events. However, in MVD patients treated with second-generation DESs, repeat revascularization incidence was similar between two different follow-up strategies up to 3 years.

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.

Background: Iatrogenic myocardial injury by radiofrequency catheter ablation (RFCA) releases proinflammatory substances from damaged myocardium, and these may contribute to endothelial dysfunction in systemic vascular structure. The aim of this study is to evaluate the effect of nonischemic myocardial damage on coronary microvascular function in patients undergoing atrial fibrillation (AF) ablation., Methods and Results: We included 49 patients who underwent AF ablation (paroxysmal AF=25, persistent AF=24) and 34 controls. Immediately before and after RFCA, index of microvascular resistance (IMR) was assessed at left anterior descending coronary artery, and blood samples were obtained for analyses of nitric oxide (NO), activated leukocyte cell adhesion molecule, and lipoprotein-associated phospholipase. Transthoracic echocardiography was performed at baseline, 1 day, 1 month, and 3 months after RFCA. Compared with baseline, IMR, activated leukocyte cell adhesion molecule, and lipoprotein-associated phospholipase increased and NO decreased after RFCA. In 36 subjects with increasing IMR, E/E' ratio increased at 1 day and returned to baseline level at 3 months after RFCA. Changes in activated leukocyte cell adhesion molecule and lipoprotein-associated phospholipase between baseline and after RFCA were independently related to the increase in IMR. In 14 subjects (28.6%), arrhythmia recurred. Using a cutoff value of 9.3 mm Hg/s, sensitivity was 56.7% and specificity was 91.2% for IMR change in predicting AF recurrence (P=0.028)., Conclusions: Myocardial damage by RFCA provoked coronary microvascular dysfunction through systemic proinflammatory reaction that may contribute to transient diastolic dysfunction. This phenomenon may represent a mechanism for early recurrence of arrhythmia after RFCA., Clinical Trial Registration: URL: http://cris.cdc.go.kr. Unique identifier: KCT0000030.

Background: Depression is a risk factor for the development of coronary heart disease but the relationship between coronary endothelial dysfunction and depression is not yet known. This study investigated whether depressive symptomatology is associated with coronary endothelial dysfunction in patients without coronary artery disease (CAD)., Methods and Results: Incremental acetylcholine (Ach; 20, 50 and 100 microg/min) and nitrate (200 microg/min) were infused into the left coronary ostium of 52 patients (male 30, 51.8 years) with depressive symptoms as indicated by a Beck Depression Inventory (BDI) score of >or=10 and a Hamilton Depression Rating Scale (HAM-D17) of >or=7 but without overt CAD or any vasoactive medications. Vascular responses to each drug were measured quantitatively at the mid-segments of the left anterior descending artery (LAD) and compared to those of 103 matched control subjects (male 64, 51.3 years) with angiographically normal looking LAD and as estimated by BDI <10 and HAM-D17 <7. Patients in the depressive group showed significant vasoconstriction compared with patients in the non-depressive group (p=0.017, 0.090, 0.004 respectively). However, endothelium-independent vasodilatation to nitrates did not differ significantly between the two groups (p=0.461). No differences in risk factors were found between the two groups., Conclusions: Depressive mood is associated with coronary endothelial dysfunction in patients without CAD, suggesting a possible mechanism by which depressive mood may act as a cardiovascular risk factor., (Copyright (c) 2009 Elsevier Ireland Ltd. All rights reserved.)

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.

Background: Although drug-eluting stents (DES) have been shown to dramatically reduce restenosis and improve the rate of event-free survival in large randomized trials, the benefit of DES appears to be limited to restenosis. In large arteries, it is not clear which type of stent is more superior in angiographic and clinical outcomes between DES and bare-metal stents (BMS). We compared the angiographic and clinical outcomes of DES versus BMS in large arteries (> or = 3.5 mm)., Method: Two hundred and forty patients from March 2002 to March 2007 received stents; 196 patients were treated with DES (44.9% sirolimus-eluting stents; 43.9% paclitaxel-eluting stents; 11.2% zotarolimus-eluting stents) and 44 with cobalt-chromium BMS for single de novo lesions in a large vessel. All subjects received aspirin, clopidogrel, and/or cilostazol as the standard antiplatelet regimen. The angiographic and clinical outcomes were evaluated at 6 months., Results: For the baseline characteristics, there were no significant differences between the DES and BMS groups. In addition, for the initially implanted stent there was no difference in the length, stent diameter, and lesion site between the two groups. After 6 months, the follow-up angiogram showed that in-stent diameter restenosis and late loss was more common with BMS than DES (39+/-21% vs. 19+/-17%, p=0.007; 1.44+/-0.83 mm vs. 0.62+/-0.58 mm, p=0.009, respectively). However, the target-lesion revascularization/target-vessel revascularization, and total major adverse cardiac events showed no significant differences between the groups (5.3% vs. 3.6%, p=0.62; 5.3% vs. 4.6%, p=0.86, respectively)., Conclusion: The DES and cobalt-chromium BMS placed in large coronary arteries showed equally favorable 6-month clinical outcomes, although the 6-month angiographic results appeared more favorable in the DES group than in the BMS group.

Objectives: We prospectively compared coronary endothelial dysfunction in patients with zotarolimus-eluting stent (ZES) versus sirolimus-eluting stent (SES) implantation at 6-month follow-up., Background: A ZES has been associated with uniform and rapid healing of the endothelium., Methods: Fifty patients were randomly treated with intravascular ultrasound-guided stenting with a single stent to the mid-segment of the left anterior descending artery (20 ZES, 20 SES, and 10 bare-metal stents), and endothelial function was estimated before and after intervention at 6-month follow-up by incremental acetylcholine (Ach) (10, 20, 50, and 100 microg/min) and nitrate (200 microg/min) infusions into the left coronary ostium. The vascular response was quantitatively measured in the 5-mm segments proximal and distal to the stent., Results: In the drug-eluting stent groups, more intense vasoconstriction to incremental doses of Ach was observed at 6-month follow-up compared with the responses before stenting. Endothelial function associated with the ZES was more preserved at 6-month follow-up compared with the SES. Vasoconstriction to Ach was more prominent in the distal segments than the proximal segments in both the ZES and SES groups. Endothelium-independent vasodilation to nitrate did not differ significantly among the study groups., Conclusions: Vasoconstriction in response to Ach in the peri-stent region was less pronounced in the ZES group than the SES group at 6-month follow-up, which suggests that endothelial function associated with ZES can be more preserved than the SES.

Objectives: This study was designed to investigate whether endothelial dysfunction is related to drug-eluting stent (DES) implantation at 6 months after stenting., Background: Current available DES could delay vessel healing and subsequently impair endothelial function., Methods: Endothelial function was estimated at 6-month follow-up in 75 patients (31 men, mean age 62.1 years) with a DES (39 sirolimus-eluting stents [SES], 36 paclitaxel-eluting stents [PES]), and 10 patients with a bare-metal stent (BMS) to the left anterior descending artery, by incremental acetylcholine (Ach) infusion (20 microg/min, 50 microg/min, 100 microg/min) and nitrate (200 microg/min) into the left coronary ostium. Vascular responses were quantitatively measured in arterial segments 5 mm proximal and distal to DES and compared with corresponding segments in the BMS group and midsegments in the left circumflex artery as a reference nonstented artery. All antianginal agents were withheld for at least 72 h before coronary angiography., Results: Greater vasoconstriction to Ach was observed in both the SES and PES groups than in the BMS group or control segments of left circumflex artery. Vasoconstriction to Ach was more prominent in arterial segments distal to stents in both SES and PES groups compared with those in the BMS group (p < 0.001). The degree of vasoconstriction to Ach was similar between the SES and PES groups. Endothelium-independent vasodilatation to nitrate did not differ significantly between the study groups., Conclusions: Abnormal vasoconstriction to Ach was found in the SES and PES groups, especially in arterial segments distal to DES at 6 months after stenting, which suggests that DES has a potential long-term adverse effect on local coronary endothelial dysfunction.