Kyoung-Im Cho

Intravascular Ultrasound-Guided Implantation of Drug-Eluting Stents to Improve Outcome: A Meta-Analysis

OBJECTIVESnThe aim of this study was to systematically review and perform a meta-analysis of randomized trials and observational studies of intravascular ultrasound (IVUS)-guided versus angiography-guided implantation of drug-eluting stents (DES).nnnBACKGROUNDnAlthough studies in the bare-metal stents era suggested that there were clinical benefits to IVUS guidance, it is still controversial whether percutaneous coronary intervention (PCI) with DES guided by IVUS leads to better clinical outcomes.nnnMETHODSnRelevant studies published through March 31, 2013, were searched for and identified in the electronic databases. Summary estimates were obtained using a random-effects model.nnnRESULTSnFrom 138 initial citations, 3 randomized trials and 12 observational studies with 24,849 patients (11,793 IVUS-guided and 13,056 angiography-guided) were included in this study. Comparison of IVUS- versus angiography-guided PCI disclosed odds ratios (ORs) for major adverse cardiac events of 0.79 (95% confidence interval [CI]: 0.69 to 0.91; pxa0= 0.001). IVUS-guided PCI was also associated with significantly lower rates of all-cause mortality (OR: 0.64; 95% CI: 0.51 to 0.81; pxa0< 0.001), myocardial infarction (OR: 0.57; 95% CI: 0.42 to 0.78; p < 0.001), target vessel revascularization (OR: 0.81; 95% CI: 0.68 to 0.95; pxa0= 0.01), and stent thrombosis (OR: 0.59; 95% CI: 0.42 to 0.82; pxa0= 0.002). Axa0meta-analysis of propensity-matched studies demonstrated similar results in terms of clinical outcomes, but not repeat revascularization.nnnCONCLUSIONSnIVUS-guided DES implantation is associated with significantly lower rates of adverse clinical events compared with angiography guidance. Further study is needed to clarify which subgroups of subjects with IVUS guidance will have greater benefit.

Meta-Analysis of Plaque Composition by Intravascular Ultrasound and Its Relation to Distal Embolization After Percutaneous Coronary Intervention

Controversies exist regarding the association between plaque composition and distal embolization phenomenon after percutaneous coronary intervention (PCI). We evaluated the effect of plaque characteristics on embolization after PCI by grayscale and virtual histology-intravascular ultrasound (IVUS). We searched PubMed, Ovid MEDLINE, and Cochrane databases for IVUS studies evaluating the coronary plaque characteristics in no reflow, distal embolization, and periprocedural myocardial infarction after PCI. Sixteen studies were included, totaling 1,697 patients who underwent PCI (292 patients with embolization and 1,405 patients without embolization). At the minimum lumen sites, the external elastic membrane (weighted mean difference 2.38 mm(2), 95% confidence interval [CI] 1.02 to 3.74) and the plaque and media cross-sectional areas (weighted mean difference 2.44 mm(2), 95% CI 1.44 to 3.45) were significantly greater in the embolization group than in the no embolization group. Pooled analysis showed that the absolute necrotic core volume (standardized mean difference 0.49, 95% CI 0.13 to 0.85), absolute (standardized mean difference 0.73, 95% CI 0.14 to 1.31) and relative (standardized mean difference 1.02, 95% CI 0.72 to 1.31) necrotic core areas at the minimum lumen sites were significantly greater in the embolization group than in the no embolization group, but the other plaque components were similar in the 2 groups. In conclusion, the necrotic core component derived from virtual histology-IVUS and the morphologic characteristics of plaque derived from grayscale IVUS are closely related to the distal embolization phenomenon after PCI.

Impact of duration and dosage of statin treatment and epicardial fat thickness on the recurrence of atrial fibrillation after electrical cardioversion

The purpose of this study was to investigate the time-dependent effect of statin treatment and echocardiographic epicardial fat thickness (EFT) on the maintenance of sinus rhythm (SR) in atrial fibrillation (AF) patients after electrical cardioversion (EC). One hundred sixty-three AF patients without previous statin treatment who underwent EC were consecutively enrolled. The maintenance rate of SR after EC (1, 3, 6, and 12xa0months) as documented by electrocardiogram and EFT were compared between patients with statin treatment (statin group, nxa0=xa063) and those without (no statin group, nxa0=xa0100). There was no significant difference in the maintenance rate of SR between the groups soon after EC (statin group; 85.7xa0% vs. no statin; 84.8xa0%, pxa0=xa00.535), after 1xa0month (71.0 vs. 59.1xa0%, pxa0=xa00.091), and after 3xa0months (63.2 vs. 50.0xa0%, pxa0=xa00.086). However, the maintenance rate of SR was significantly higher in the statin group compared to no statin group (61.8 vs. 42.9xa0%, pxa0=xa00.024) after 6xa0months, and this significant difference persisted up to 12xa0months of follow up (60.1 vs. 36.4xa0%, pxa0=xa00.001). Patients with recurrence showed higher baseline EFT (7.4xa0±xa02.7 vs. 8.5xa0±xa03.0xa0mm, pxa0=xa00.014). Multivariate linear regression analysis indicated that EFT, left atrial diameter, high-density lipoprotein cholesterol, statin treatment, and dose were the significant contributors to the maintenance of SR for all periods after EC. Statin treatment and low EFT were associated with a higher maintenance rate of SR in AF patients after EC. Significant benefit of statin was realized 6xa0months after EC, and this benefit was shown to be maintained over time.

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.

Attenuation of Acetylcholine Activated Potassium Current (IKACh) by Simvastatin, Not Pravastatin in Mouse Atrial Cardiomyocyte: Possible Atrial Fibrillation Preventing Effects of Statin

Statins, 3-hydroxy-3-methyl-glutaryl-CoA reductase inhibitors, are associated with the prevention of atrial fibrillation (AF) by pleiotropic effects. Recent clinical trial studies have demonstrated conflicting results on anti-arrhythmia between lipophilic and hydrophilic statins. However, the underlying mechanisms responsible for anti-arrhythmogenic effects of statins are largely unexplored. In this study, we evaluated the different roles of lipophilic and hydrophilic statins (simvastatin and pravastatin, respectively) in acetylcholine (100 µM)-activated K+ current (IKACh, recorded by nystatin-perforated whole cell patch clamp technique) which are important for AF initiation and maintenance in mouse atrial cardiomyocytes. Our results showed that simvastatin (1–10 µM) inhibited both peak and quasi-steady-state IKACh in a dose-dependent manner. In contrast, pravastatin (10 µM) had no effect on IKACh. Supplementation of substrates for the synthesis of cholesterol (mevalonate, geranylgeranyl pyrophosphate or farnesyl pyrophosphate) did not reverse the effect of simvastatin on IKACh, suggesting a cholesterol-independent effect on IKACh. Furthermore, supplementation of phosphatidylinositol 4,5-bisphosphate, extracellular perfusion of phospholipase C inhibitor or a protein kinase C (PKC) inhibitor had no effect on the inhibitory activity of simvastatin on I KACh. Simvastatin also inhibits adenosine activated IKACh, however, simvastatin does not inhibit IKACh after activated by intracellular loading of GTP gamma S. Importantly, shortening of the action potential duration by acetylcholine was restored by simvastatin but not by pravastatin. Together, these findings demonstrate that lipophilic statins but not hydrophilic statins attenuate IKACh in atrial cardiomyocytes via a mechanism that is independent of cholesterol synthesis or PKC pathway, but may be via the blockade of acetylcholine binding site. Our results may provide important background information for the use of statins in patients with AF.

Meta-Analysis of Multivessel Versus Culprit-Only Percutaneous Coronary Intervention in Patients With Non–ST-Segment Elevation Acute Coronary Syndrome and Multivessel Coronary Disease

Even in the era of contemporary drug-eluting stents, it is not clear whether percutaneous coronary intervention (PCI) for nonculprit lesions can improve long-term outcomes in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS) with multivessel coronary disease. Relevant studies published through August 2014 were searched and identified in the electronic databases. Summary estimates were obtained using a random-effects model. From 368 initial citations, 8 observational studies with 8,425 patients (3,227 multivessel and 5,198 culprit-only PCI) were included. Mean follow-up duration was 18xa0months. There were no significant differences in all-cause mortality (odds ratios [ORs] 0.85, 95% confidence interval [CI] 0.70 to 1.04) and myocardial infarction (OR 0.86, 95% CI 0.55 to 1.35). However, multivessel PCI was associated with a significantly lower rate of repeat revascularization (OR 0.75, 95% CI 0.56 to 1.00). Comparison of multivessel versus culprit-only PCI disclosed OR for major adverse cardiac events of 0.74 (95% CI 0.57 to 0.97). In conclusion, multivessel PCI reduced repeat revascularization without significant benefits in terms of mortality or myocardial infarction at the long-term follow-up in patients with NSTE-ACS and multivessel coronary disease. Future randomized studies that examine the safety and efficacy of multivessel PCI in NSTE-ACS are warranted.

Association among epicardial fat, heart rate recovery and circadian blood pressure variability in patients with hypertension

BackgroundEpicardial fat tissue is known to have an unique endocrine function which affect the cardiac autonomic system. Heart rate recovery (HRR) is a simple non-invasive measurement that assesses autonomic nervous system dysfunction. We aimed to investigate the association among epicardial fat thickness (EFT), HRR and circadian blood pressure (BP) variation in patients with hypertension.MethodsA total of 358 consecutive patients who underwent both 24-hour ambulatory BP monitoring (ABPM) and a treadmill test were enrolled. Echocardiographic EFT and HRR, defined as peak heart rate minus heart rate after a 1-min recovery time, were measured. Patients were classified according to the ABPM; 147 patients with hypertension with a dipping pattern at night (dippers), 140 patients with hypertension with a non-dipping pattern at night (non-dippers) and 71 normotensive controls.ResultsEFT was significantly higher in hypertensive patients, especially in the non-dipper group, compared to the controls (non-dippers, 7.5u2009±u20092.9xa0mm; dippers, 6.6u2009±u20091.6xa0mm; controls, 5.5u2009±u20092.1xa0mm; pu2009<u20090.001). HRR was significantly lower in both hypertensive groups as compared to the control group and was the lowest in the non-dipper group (non-dipper, 26.6u2009±u200918.6; dipper, 29.5u2009±u200921.5; control, 71.4u2009±u200919.8; pu2009<u20090.001). EFT was significantly correlated with age, body mass index, 24-hour mean systolic BP and 24xa0h mean BP variability, whereas exercise duration, metabolic equivalents (METs) and HRR were inversely correlated with EFT. Furthermore, EFTu2009>u20096.7xa0mm was associated with a blunted HRR with 76xa0% sensitivity and 61xa0% specificity (ROC area under curve: 0.71, 95xa0% confidence interval, CIu2009=u20090.65–0.76, pu2009<u20090.001). In a multivariate analysis, EFT (odds ratio, ORu2009=u20093.53, 95xa0% CIu2009=u20091.20–10.37, pu2009=u20090.022) and 24-hour mean BP variability (ORu2009=u20091.09, 95xa0% CIu2009=u20091.03–1.16, pu2009=u20090.005) were independent predictors of a blunted HRR defined as HRRu2009≤u200912 beats (nu2009=u200963) in patients with hypertension.ConclusionEFT and HRR were significantly correlated with circadian BP variability in patients with hypertension. EFT and circadian BP variability were independent predictors of blunted HRR, which suggests a link between epicardial fat and autonomic dysregulation in hypertension.

Echocardiographic Assessment of Structural and Hemodynamic Changes in Hypertension-Related Pregnancy

Background Pregnancy induces dramatic cardiovascular changes in order to meet the increasing metabolic needs. Adaptive change of left ventricle (LV) might be modified in pregnancy complicated by hypertension. Methods Data from 193 consecutive pregnant women were analyzed. Clinical and echocardiographic data were compared in normotensive and hypertensive women. Results Significantly higher LV mass indexed by height was observed in hypertensive women compared with normotensive women (84 ± 21 g/m vs. 97 ± 20 g/m, p = 0.001). Diastolic function measured by the ratio of peak velocity of early diastolic transmitral blood flow to early diastolic mitral annular velocity was impaired in hypertensive women (11.0 ± 3.0 vs. 9.2 ± 2.5, p < 0.001). Such change was more prominent in women with gestational hypertension (GH) than those with chronic hypertension (CH). Heavy maternal weight was an independent factor associated with LV hypertrophy (LVH) in both normotensive and hypertensive women. Overt eccentric LVH was more frequent than concentric remodeling/hypertrophy (24% vs. 8.4%) in GH, while the opposite result was observed in CH (14% vs. 23%). Conclusion Hypertensive pregnancy is associated with significant LVH and diastolic dysfunction. CH seems to induce different LV remodeling pattern from GH. Heavy maternal weight during pregnancy might intensify the unfavorable remodeling of LV, particularly in hypertensive pregnancy.

Impact of cilostazol on the progression of carotid atherosclerosis in patients with retinal vascular occlusion.

BACKGROUNDnCilostazol, a selective phosphodiesterase three inhibitor, has been proposed to have beneficial effects in the prevention of atherosclerosis.nnnAIMSnWe aimed to investigate the effects of cilostazol on carotid intima-media thickening (IMT) and total plaque area (TPA) in patients with retinal vascular occlusion.nnnMETHODSnA total of 63 consecutive vascular occlusive retinopathy patients with carotid atherosclerosis were enrolled. We examined changes in the carotid IMT/TPA and visual acuity/macular thickness before and after 1-year treatment with cilostazol (200xa0mg/day).nnnRESULTSnThe mean IMT of both common carotid arteries (CCAs) and internal carotid arteries (ICAs) were significantly reduced after cilostazol treatment. There was no significant difference in the TPA of both CCAs before and after the treatment (before; 0.61xa0±xa00.94 vs. after; 0.45xa0±xa00.79xa0cm(2) , Pxa0=xa00.291); however, significant plaque regression (before; 0.14xa0±xa00.15 vs. after; 0.25xa0±xa00.14 cm(2) , Pxa0=xa00.004) was observed in selected patients (nxa0=xa030) with a TPA <0.5xa0cm(2) . The improvement in macular thickness was significantly associated with an improvement in carotid IMT (rxa0=xa00.42, Pxa0=xa00.001) and TPA (rxa0=xa00.23, Pxa0=xa00.04).nnnCONCLUSIONnCilostazol potently inhibited the progression of carotid IMT and may play a role in the early carotid plaque regression in patients with retinal vascular occlusion.

Association between the N-terminal plasma brain natriuretic peptide levels or elevated left ventricular filling pressure and thromboembolic risk in patients with non-valvular atrial fibrillation

BACKGROUNDnWe aimed to investigate the role of brain natriuretic peptide (BNP) levels and left ventricular (LV) filling pressures in thromboembolic risk in patients with non-valvular atrial fibrillation (AF).nnnMETHODSnAmong 327 patients with non-valvular AF, the ratio of peak early filling velocity to mitral annulus velocity (E/Ea) and N-terminal proBNP (NT-proBNP) was compared according to the presence of left atrial appendage (LAA) dysfunction [presence of spontaneous echo contrast (SEC)≥grade 3 and/or reduced LAA emptying flow velocity <20cm/s].nnnRESULTSnCompared to patients without LAA dysfunction, patients with LAA dysfunction presented with significantly higher CHADS2 scores (1.24±1.14 vs. 1.68±1.31, p=0.005), high-sensitivity C-reactive protein (0.36±1.18mg/dl vs. 0.66±1.32mg/dl, p=0.043), and NT-proBNP (765.3±2534.8pg/ml vs. 2266.9±6117.4pg/ml, p=0.002). Furthermore, patients with LAA dysfunction showed significantly higher left atrial volume index (LAVI, 25.1±10.9 vs. 43.1±22.1, p<0.001) and E/Ea (10.8±7.27 vs. 7.97±2.50mg/dl, p<0.001). Plasma logNT-proBNP levels were significantly correlated with the presence of SEC (r=0.276, p<0.001), LAA emptying flow velocity (r=-0.492, p<0.001), LAVI (r=0.405, p<0.001), and E/Ea (r=0.353, p<0.001). Binary logistic regression analysis showed that high NT-proBNP level >249.7pg/ml (odds ratio, OR 6.79, 95% confidence interval, CI 3.16-15.55, p<0.001) and E/Ea >10 (OR 4.41, 95% CI 2.39-8.15, p<0.001) were independent predictors of LAA dysfunction after adjustment of known thromboembolic risk factors.nnnCONCLUSIONnElevated plasma NT-proBNP concentrations and LV filling pressures represented by LAA dysfunction may be reliable surrogate markers for predicting thromboembolic risk in patients with AF.