Cheol Ung Choi

A prospective, randomized, 6-month comparison of the coronary vasomotor response associated with a zotarolimus- versus a sirolimus-eluting stent: differential recovery of coronary endothelial dysfunction.

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.

Six-Month Comparison of Coronary Endothelial Dysfunction Associated With Sirolimus-Eluting Stent Versus Paclitaxel-Eluting Stent

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.

Total and interatrial epicardial adipose tissues are independently associated with left atrial remodeling in patients with atrial fibrillation.

Epicardial Adipose Tissue in Atrial Fibrillation. Introduction: As epicardial adipose tissue (EAT) is a metabolically active visceral fat, potential interaction between EAT and myocardium is strongly suggested. The aims of this study were to determine whether the amount and regional distribution of EAT are related to the chronicity of atrial fibrillation (AF) and left atrial (LA) remodeling.

Relationship between blood pressure parameters and pulse wave velocity in normotensive and hypertensive subjects: invasive study

Blood pressure (BP) is one of the most important contributing factors to pulse wave velocity (PWV), a classic measure of arterial stiffness. Although there have been many non-invasive studies to show the relation between arterial stiffness and BP, the results are controversial. The aim of this study is to evaluate the role of BP as an influencing factor on PWV using invasive method. We observed 174 normotensive and untreated hypertensive subjects using coronary angiography. Arterial stiffness was assessed through aorto-femoral PWV by foot-to-foot velocity method using fluid-filled system. And BP was measured by pressure wave at the right common femoral artery. From univariate analysis, age, diabetes mellitus (DM), hypertension, waist, waist-to-hip ratio, total cholesterol-to-high-density lipoprotein cholesterol ratio, systolic BP (SBP), pulse pressure (PP) and mean arterial pressure (MAP) showed significant association with PWV. To avoid multiple colinearity among SBP, PP and MAP, we performed multiple regression analysis predicting PWV thrice. Age, DM and each BP were significantly and consistently correlated to PWV. In the first and third modules, compared to age, SBP and MAP were less strong predictors, respectively. However, PP was the stronger predictor than age and DM in the second module. Lastly, we simultaneously forced MAP and PP with other variables in the fourth multivariate analysis. Age, DM and PP remained significantly correlated with PWV, but the significance of MAP was lost. This is the first invasive study to suggest that PP has the strongest correlation with PWV among a variety of BP parameters.

Improved endothelial function in patients with atrial fibrillation through maintenance of sinus rhythm by successful catheter ablation.

Effect of Ablation on Endothelial Function. Background: Although atrial fibrillation (AF) is a risk factor for endothelial dysfunction (ED), the effect of catheter ablation (CA) on AF‐associated ED has not been evaluated. The aims of this study are to determine if the degree of ED predicts the outcome of AF ablation and to evaluate whether ED can be improved through restoring sinus rhythm (SR) by successful CA.

Does isolation of the left atrial posterior wall improve clinical outcomes after radiofrequency catheter ablation for persistent atrial fibrillation?: A prospective randomized clinical trial

INTRODUCTION Although posterior wall of left atrium (LA) is known to be arrhythmogenic focus, little is known about the effect of posterior wall isolation (PWI) in patients who undergo radiofrequency catheter ablation (RFCA) for persistent atrial fibrillation (PeAF). METHODS We randomly assigned 120 consecutive PeAF patients to additional PWI [PWI (+), n=60] or control [PWI (-), n=60] groups. In all patients, linear ablation was performed after circumferential pulmonary vein isolation (PVI). Linear lesions included roof, anterior perimitral, and cavotricuspid isthmus lines with conduction block. In PWI (+) group, posterior inferior linear lesion was also conducted. Creatine kinase-MB (CK-MB) and troponin-T levels were measured 1day after RFCA. LA emptying fraction (LAEF) was assessed before and 12 months after RFCA. RESULTS A total of 120 subjects were followed for 12 months after RFCA. There were no significant differences between two groups in baseline demographics and LA volume (LAV). The levels of CK-MB and troponin-T and procedure time were not significantly different between the groups. AF termination during RFCA was more frequently observed in PWI (+) than control (P=0.035). During follow-up period, recurrence occurred in 10 (16.7%) patients in PWI (+) and 22 (36.7%) in control (P=0.02). The change in LAEF was not significantly different between the groups. On multivariate analysis, smaller LAV and additional PWI were independently associated with procedure outcome. CONCLUSIONS PWI in addition to PVI plus linear lesions was an efficient strategy without deterioration of LA pump function in patients who underwent RFCA for PeAF.

Myocardial bridging is related to endothelial dysfunction but not to plaque as assessed by intracoronary ultrasound

Background: Myocardial bridge (MB) is characterised by focal compression of a coronary artery in systole by an overlying band of myocardium. Chronic compression and relaxation of the MB may produce endothelial dysfunction by direct stress. Objective: To determine whether MB alters endothelial function, thus influencing the plaque formation. Methods: 128 patients (mean (SD) age 54.7 (10.9) years, 56 men) with typical angiographic systolic milking effects and >30% reduction in diameter of the coronary artery during systole after intracoronary nitrate (glyceryl trinitrate, 200 μg) infusion were studied. 231 control patients (mean (SD) age 52.9 (12.1) years, 111 men) without overt coronary artery disease including MB were also studied. Endothelial function was estimated by incremental acetylcholine (Ach) infusion into the left coronary ostium. Intracoronary ultrasound assessments were obtained in 74/128 patients with MB and 81/231 controls. Results: The mean (SD) vasoconstrictive response to maximal Ach was more pronounced at the bridging segments than at matched segments in controls (−71.9 (14.9) vs −30.3 (22.6), p = 0.009). Coronary vasoconstriction (>50%) to Ach was seen more often in the MB group than in controls (114/128 (89.1%) vs 81/231 (35.1%), p = 0.007). No significant correlation was found between the severity of MB and vasoconstriction in response to Ach. A typical half-moon phenomenon was seen in 71/74 (95.9%) cases of the MB group, but not in controls (p<0.001). Plaques at the bridging segments were absent in 67/74 (90.5%) and mild in 7/74 (9.5%) cases, as compared with those of matched segments of the left anterior descending coronary artery in controls (plaque burden 5.91 (1.37)% vs 24.71 (24.21)%, p = 0.002). Conclusion: Despite the prominent relationship between MB and endothelial dysfunction, bridging segments are spared from atherosclerotic plaque formation.

Usefulness of coronary pressure measurement for functional evaluation of drug-eluting stent restenosis.

Despite the widespread adoption of drug-eluting stent (DES) implantation, the optimal treatment of DES failures remains challenging. The present study evaluated the relation between quantitative angiography and the fractional flow reserve (FFR) in restenotic lesions after DES implantation and the efficacy of FFR in determining whether to treat these lesions. To assess their functional significance, the coronary pressure-derived FFR was measured in 50 DES restenotic lesions (49 patients). Additional intervention was performed in lesions with a FFR <0.8. Major adverse cardiac events were assessed at 12 months after the reintervention procedure. The mean percent diameter stenosis (%DS) was 58 ± 13%. Of the 50 lesions, 20 (40%) were deferred without additional intervention. The FFR and %DS had a negative correlation (r = -0.61, p <0.001). However, when only the lesions with diffuse-type restenosis (15 lesions) were analyzed, the degree of correlation decreased (r = -0.56, p = 0.12). Although most lesions (89%) with a %DS of ≥70 had significant functional ischemia, among 41 lesions with a %DS <70, only 20 (49%) had demonstrated functional patency. The incidence of adverse events during the 12 months of follow-up after FFR-guided treatment was 18.0% (23.3% in the FFR <0.80 group and 10.0% in FFR ≥0.80 group). In conclusion, a discrepancy was found between functional ischemia measured by the FFR and the angiographic %DS, in particular, in moderate- or diffuse-type restenotic lesions after DES implantation. The outcome of FFR-guided deferral in patients with DES in-stent restenosis seems favorable.

Differing effects of aging on central and peripheral blood pressures and pulse wave velocity: a direct intraarterial study.

Objectives There have been a few noninvasive studies showing the effect of aging on blood pressure (BP) and pulse wave velocity (PWV) in different arterial segments. The aim of this study was to evaluate the effect of aging on arterial hemodynamics in central and peripheral arteries using an invasive method. Methods We observed 175 individuals undergoing coronary angiography. SBP and DBP were measured by pressure wave at the radial artery, abdominal aorta, and aortic arch. Aortic arch-abdominal aorta PWV (aoPWV) and aortic arch-radial artery PWV (arPWV) were also assessed by the foot-to-foot velocity method using a fluid-filled system. Results SBP and pulse pressure were significantly positively correlated and DBP was significantly negatively correlated with age through the arterial tree in a multivariate analysis after adjusting for sex, coronary artery disease, diabetes, dyslipidemia, smoking status, and the use of antihypertensive agents. Pulse pressure, SBP, and DBP were significantly associated with age (ranked in order of association strength) at all studied arterial segments. Each central BP showed a consistently higher correlation with age than radial BP. aoPWV and arPWV were also significantly correlated with age, and this relationship was much stronger for aoPWV (r = 0.474, P < 0.001) than for arPWV (r = 0.224, P = 0.003). Conclusion The present invasive study suggests that aging has a greater effect on central rather than peripheral arterial hemodynamics. The central pulse pressure was the predominant BP affected by aging, which could be caused by the stronger relationship of aging with central arterial stiffness.

Coronary endothelial dysfunction associated with a depressive mood in patients with atypical angina but angiographically normal coronary artery

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.