Hyeon Cheol Gwon

Randomized Trial of Stents versus Bypass Surgery for Left Main Coronary Artery Disease

BACKGROUND Percutaneous coronary intervention (PCI) is increasingly used to treat unprotected left main coronary artery stenosis, although coronary-artery bypass grafting (CABG) has been considered to be the treatment of choice. METHODS We randomly assigned patients with unprotected left main coronary artery stenosis to undergo CABG (300 patients) or PCI with sirolimus-eluting stents (300 patients). Using a wide margin for noninferiority, we compared the groups with respect to the primary composite end point of major adverse cardiac or cerebrovascular events (death from any cause, myocardial infarction, stroke, or ischemia-driven target-vessel revascularization) at 1 year. Event rates at 2 years were also compared between the two groups. RESULTS The primary end point occurred in 26 patients assigned to PCI as compared with 20 patients assigned to CABG (cumulative event rate, 8.7% vs. 6.7%; absolute risk difference, 2.0 percentage points; 95% confidence interval [CI], -1.6 to 5.6; P=0.01 for noninferiority). By 2 years, the primary end point had occurred in 36 patients in the PCI group as compared with 24 in the CABG group (cumulative event rate, 12.2% vs. 8.1%; hazard ratio with PCI, 1.50; 95% CI, 0.90 to 2.52; P=0.12). The composite rate of death, myocardial infarction, or stroke at 2 years occurred in 13 and 14 patients in the two groups, respectively (cumulative event rate, 4.4% and 4.7%, respectively; hazard ratio, 0.92; 95% CI, 0.43 to 1.96; P=0.83). Ischemia-driven target-vessel revascularization occurred in 26 patients in the PCI group as compared with 12 patients in the CABG group (cumulative event rate, 9.0% vs. 4.2%; hazard ratio, 2.18; 95% CI, 1.10 to 4.32; P=0.02). CONCLUSIONS In this randomized trial involving patients with unprotected left main coronary artery stenosis, PCI with sirolimus-eluting stents was shown to be noninferior to CABG with respect to major adverse cardiac or cerebrovascular events. However, the noninferiority margin was wide, and the results cannot be considered clinically directive. (Funded by the Cardiovascular Research Foundation, Seoul, Korea, and others; PRECOMBAT ClinicalTrials.gov number, NCT00422968.).

Six-Month Versus 12-Month Dual Antiplatelet Therapy After Implantation of Drug-Eluting Stents The Efficacy of Xience/Promus Versus Cypher to Reduce Late Loss After Stenting (EXCELLENT) Randomized, Multicenter Study

Background— The optimal duration of dual antiplatelet therapy (DAPT) after implantation of drug-eluting coronary stents remains undetermined. We aimed to test whether 6-month DAPT would be noninferior to 12-month DAPT after implantation of drug-eluting stents. Methods and Results— We randomly assigned 1443 patients undergoing implantation of drug-eluting stents to receive 6- or 12-month DAPT (in a 1:1 ratio). The primary end point was a target vessel failure, defined as the composite of cardiac death, myocardial infarction, or ischemia-driven target vessel revascularization at 12 months. Rates of target vessel failure at 12 months were 4.8% in the 6-month DAPT group and 4.3% in the 12-month DAPT group (the upper limit of 1-sided 95% confidence interval, 2.4%; P =0.001 for noninferiority with a predefined noninferiority margin of 4.0%). Although stent thrombosis tended to occur more frequently in the 6-month DAPT group than in the 12-month group (0.9% versus 0.1%; hazard ratio, 6.02; 95% confidence interval, 0.72–49.96; P =0.10), the risk of death or myocardial infarction did not differ in the 2 groups (2.4% versus 1.9%; hazard ratio, 1.21; 95% confidence interval, 0.60–2.47; P =0.58). In the prespecified subgroup analysis, target vessel failure occurred more frequently in the 6-month DAPT group than in the 12-month group (hazard ratio, 3.16; 95% confidence interval, 1.42–7.03; P =0.005) among diabetic patients. Conclusions— Six-month DAPT did not increase the risk of target vessel failure at 12 months after implantation of drug-eluting stents compared with 12-month DAPT. However, the noninferiority margin was wide, and the study was underpowered for death or myocardial infarction. Our results need to be confirmed in larger trials. Clinical Trial Registration— URL: . Unique identifier: [NCT00698607][1]. # Clinical Perspective {#article-title-31} [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT00698607&atom=%2Fcirculationaha%2F125%2F3%2F505.atomBackground— The optimal duration of dual antiplatelet therapy (DAPT) after implantation of drug-eluting coronary stents remains undetermined. We aimed to test whether 6-month DAPT would be noninferior to 12-month DAPT after implantation of drug-eluting stents. Methods and Results— We randomly assigned 1443 patients undergoing implantation of drug-eluting stents to receive 6- or 12-month DAPT (in a 1:1 ratio). The primary end point was a target vessel failure, defined as the composite of cardiac death, myocardial infarction, or ischemia-driven target vessel revascularization at 12 months. Rates of target vessel failure at 12 months were 4.8% in the 6-month DAPT group and 4.3% in the 12-month DAPT group (the upper limit of 1-sided 95% confidence interval, 2.4%; P=0.001 for noninferiority with a predefined noninferiority margin of 4.0%). Although stent thrombosis tended to occur more frequently in the 6-month DAPT group than in the 12-month group (0.9% versus 0.1%; hazard ratio, 6.02; 95% confidence interval, 0.72–49.96; P=0.10), the risk of death or myocardial infarction did not differ in the 2 groups (2.4% versus 1.9%; hazard ratio, 1.21; 95% confidence interval, 0.60–2.47; P=0.58). In the prespecified subgroup analysis, target vessel failure occurred more frequently in the 6-month DAPT group than in the 12-month group (hazard ratio, 3.16; 95% confidence interval, 1.42–7.03; P=0.005) among diabetic patients. Conclusions— Six-month DAPT did not increase the risk of target vessel failure at 12 months after implantation of drug-eluting stents compared with 12-month DAPT. However, the noninferiority margin was wide, and the study was underpowered for death or myocardial infarction. Our results need to be confirmed in larger trials. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00698607.

Intracoronary Transluminal Attenuation Gradient in Coronary CT Angiography for Determining Coronary Artery Stenosis

Coronary computed tomography angiography (CTA) assessment of calcified or complex coronary lesions is frequently challenging. Transluminal attenuation gradient (TAG), defined as the linear regression coefficient between luminal attenuation and axial distance, has a potential to evaluate the degree of coronary stenosis. We examined the value of TAG in determining the stenosis severity on 64-slice coronary CTA. The value of TAG of 370 major coronary arteries was measured from 7,263 intervals of 5-mm length. Compared with coronary CTA and invasive coronary angiography, TAG decreased consistently and significantly with maximum stenosis severity on a per-vessel basis, from -1.91 ± 4.25 Hounsfield units/10 mm for diameter stenosis of 0% to 49% to -13.37 ± 9.81 Hounsfield units/10 mm for diameter stenosis of 100% (p < 0.0001). Adding TAG to the interpretation of coronary CTA improved diagnostic accuracy (p = 0.001), especially in vessels with calcified lesions (N = 127; net reclassification improvement 0.095; p = 0.046). TAG appears to be able to contribute to improved classification of coronary artery stenosis severity in coronary CTA, especially in severely calcified lesions.

Randomized Trial of Stents Versus Bypass Surgery for Left Main Coronary Artery Disease 5-Year Outcomes of the PRECOMBAT Study

BACKGROUND In a previous randomized trial, we found that percutaneous coronary intervention (PCI) was not inferior to coronary artery bypass grafting (CABG) for the treatment of unprotected left main coronary artery stenosis at 1 year. OBJECTIVES This study sought to determine the 5-year outcomes of PCI compared with CABG for the treatment of unprotected left main coronary artery stenosis. METHODS We randomly assigned 600 patients with unprotected left main coronary artery stenosis to undergo PCI with a sirolimus-eluting stent (n = 300) or CABG (n = 300). The primary endpoint was a major adverse cardiac or cerebrovascular event (MACCE: a composite of death from any cause, myocardial infarction, stroke, or ischemia-driven target vessel revascularization) and compared on an intention-to-treat basis. RESULTS At 5 years, MACCE occurred in 52 patients in the PCI group and 42 patients in the CABG group (cumulative event rates of 17.5% and 14.3%, respectively; hazard ratio [HR]: 1.27; 95% confidence interval [CI]: 0.84 to 1.90; p = 0.26). The 2 groups did not differ significantly in terms of death from any cause, myocardial infarction, or stroke as well as their composite (8.4% and 9.6%; HR, 0.89; 95% CI, 0.52 to 1.52; p = 0.66). Ischemia-driven target vessel revascularization occurred more frequently in the PCI group than in the CABG group (11.4% and 5.5%, respectively; HR: 2.11; 95% CI: 1.16 to 3.84; p = 0.012). CONCLUSIONS During 5 years of follow-up, our study did not show significant difference regarding the rate of MACCE between patients who underwent PCI with a sirolimus-eluting stent and those who underwent CABG. However, considering the limited power of our study, our results should be interpreted with caution. (Bypass Surgery Versus Angioplasty Using Sirolimus-Eluting Stent in Patients With Left Main Coronary Artery Disease [PRECOMBAT]; NCT00422968).

Everolimus-Eluting Versus Sirolimus-Eluting Stents in Patients Undergoing Percutaneous Coronary Intervention The EXCELLENT (Efficacy of Xience/Promus Versus Cypher to Reduce Late Loss After Stenting) Randomized Trial

OBJECTIVES The goal of this study was to compare the angiographic outcomes of everolimus-eluting stents (EES) and sirolimus-eluting stents (SES) in a head-to-head manner. BACKGROUND EES have been shown to be superior to paclitaxel-eluting stents in inhibiting late loss (LL) and clinical outcome. Whether EES may provide similar angiographic and clinical outcomes compared with SES is undetermined. METHODS This was a prospective, randomized, open-label, multicenter trial to demonstrate the noninferiority of EES compared with SES in preventing LL at 9 months. A total of 1,443 patients undergoing percutaneous coronary intervention were randomized 3:1 to receive EES or SES. Routine follow-up angiography was recommended at 9 months. The primary endpoint was in-segment LL at 9 months, and major secondary endpoints included in-stent LL at 9 months, target lesion failure, cardiac death, nonfatal myocardial infarction, target lesion revascularization, and stent thrombosis at 12 months. Data were managed by an independent management center, and clinical events were adjudicated by an independent adjudication committee. RESULTS Clinical follow-up was available in 1,428 patients and angiographic follow-up in 924 patients (1,215 lesions). The primary endpoint of the study (in-segment LL at 9 months) was 0.11 ± 0.38 mm and 0.06 ± 0.36 mm for EES and SES, respectively (p for noninferiority = 0.0382). The in-stent LL was also noninferior (EES 0.19 ± 0.35 mm; SES 0.15 ± 0.34 mm; p for noninferiority = 0.0121). The incidence of clinical endpoints was not statistically different between the 2 groups, including target lesion failure (3.75% vs. 3.05%; p = 0.53) and stent thrombosis (0.37% vs. 0.83%; p = 0.38). CONCLUSIONS EES were noninferior to SES in inhibition of LL after stenting, which was corroborated by similar rates of clinical outcomes. (Efficacy of Xience/Promus Versus Cypher in Reducing Late Loss After Stenting [EXCELLENT]; NCT00698607).

Ischemic postconditioning during primary percutaneous coronary intervention: the effects of postconditioning on myocardial reperfusion in patients with ST-segment elevation myocardial infarction (POST) randomized trial.

Background— Ischemic postconditioning has been reported to reduce infarct size in patients with ST-segment–elevation myocardial infarction. However, cardioprotective effects of postconditioning have not been demonstrated in a large-scale trial. Methods and Results— We performed a multicenter, prospective, randomized, open-label, blinded end-point trial. A total of 700 patients undergoing primary percutaneous coronary intervention (PCI) for ST-segment–elevation myocardial infarction within 12 hours after symptom onset were randomly assigned to the postconditioning group or to the conventional primary PCI group in a 1:1 ratio. Postconditioning was performed immediately after restoration of coronary flow as follows: The angioplasty balloon was positioned at the culprit lesion and inflated 4 times for 1 minute with low-pressure (<6 atm) inflations, each separated by 1 minute of deflation. The primary end point was complete ST-segment resolution (percentage resolution of ST-segment elevation >70%) measured at 30 minutes after PCI. Complete ST-segment resolution occurred in 40.5% of patients in the postconditioning group and 41.5% of patients in the conventional PCI group (absolute difference, −1.0%; 95% confidence interval, −8.4 to 6.4; P=0.79). The rate of myocardial blush grade of 0 or 1 and the rate of major adverse cardiac events (a composite of death, myocardial infarction, severe heart failure, or stent thrombosis) at 30 days did not differ significantly between the postconditioning group and the conventional PCI group (17.2% versus 22.4% [P=0.20] and 4.3% versus 3.7% [P=0.70], respectively). Conclusion— Ischemic postconditioning did not improve myocardial reperfusion in patients with ST-segment–elevation myocardial infarction undergoing primary PCI with current standard practice. Clinical Trial Registration— URL: http://clinicaltrials.gov. Unique identifier: NCT00942500.Background —Ischemic postconditioning has been reported to reduce infarct size in patients with ST-segment elevation myocardial infarction (STEMI). However, cardioprotective effects of postconditioning have not been demonstrated in a large-scale trial. Methods and Results —We performed a multicenter, prospective, randomized, open-label, blinded endpoint trial. A total of 700 patients undergoing primary percutaneous coronary intervention (PCI) for STEMI within 12 hours after symptom onset were randomly assigned to the postconditioning group or the conventional primary PCI group in a 1:1 ratio. Postconditioning was performed immediately after restoration of coronary flow as follows: the angioplasty balloon was positioned at the culprit lesion, and inflated 4 times for 1 minute with low-pressure ( 70%) measured at 30 minutes after PCI. Complete ST-segment resolution occurred in 40.5% of patients in the postconditioning group and 41.5% of patients in the conventional PCI group (absolute difference, -1.0%; 95% confidence interval, -8.4% to 6.4%; P =0.79). The rate of myocardial blush grade of 0 or 1 and the major adverse cardiac events (a composite of death, myocardial infarction, severe heart failure, or stent thrombosis) at 30 days did not differ significantly between the postconditioning group and the conventional PCI group (17.2% versus 22.4%, P =0.20, and 4.3% versus 3.7%, P =0.70, respectively). Conclusions —Ischemic postconditioning did not improve myocardial reperfusion in patients with STEMI undergoing primary PCI with current standard practice. Clinical Trial Registration Information —http://ClinicalTrials.gov. Identifier: [NCT00942500][1]. [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT00942500&atom=%2Fcirculationaha%2Fearly%2F2013%2F09%2F25%2FCIRCULATIONAHA.113.001690.atom

Predictors and Outcomes of Side Branch Occlusion After Main Vessel Stenting in Coronary Bifurcation Lesions: Results From the COBIS II Registry (COronary BIfurcation Stenting)

OBJECTIVES This study sought to investigate the predictors and outcomes of side branch (SB) occlusion after main vessel (MV) stenting in coronary bifurcation lesions. BACKGROUND SB occlusion is a serious complication that occurs during percutaneous coronary intervention (PCI) for bifurcation lesions. METHODS Consecutive patients undergoing PCI using drug-eluting stents for bifurcation lesions with SB ≥2.3 mm were enrolled. We selected patients treated with the 1-stent technique or MV stenting first strategy. SB occlusion after MV stenting was defined as Thrombolysis in Myocardial Infarction flow grade <3. RESULTS SB occlusion occurred in 187 (8.4%) of 2,227 bifurcation lesions. In multivariate analysis, independent predictors of SB occlusion were pre-procedural percent diameter stenosis of the SB ≥50% (odds ratio [OR]: 2.34; 95% confidence interval [CI]: 1.59 to 3.43; p < 0.001) and the proximal MV ≥50% (OR: 2.34; 95% CI: 1.57 to 3.50; p < 0.001), SB lesion length (OR: 1.03; 95% CI: 1.003 to 1.06; p = 0.03), and acute coronary syndrome (OR: 1.53; 95% CI: 1.06 to 2.19; p = 0.02). Of 187 occluded SBs, flow was restored spontaneously in 26 (13.9%) and by SB intervention in 103 (55.1%) but not in 58 (31.0%). Jailed wire in the SB was associated with flow recovery (74.8% vs. 57.8%, p = 0.02). Cardiac death or myocardial infarction occurred more frequently in patients with SB occlusion than in those without SB occlusion (adjusted hazard ratio: 2.34; 95% CI: 1.15 to 4.77; p = 0.02). CONCLUSIONS Angiographic findings of SB, proximal MV stenosis, and clinical presentation are predictive of SB occlusion after MV stenting. Occlusion of sizable SB is associated with adverse clinical outcomes..

Impact of intravascular ultrasound guidance on long-term clinical outcomes in patients treated with drug-eluting stent for bifurcation lesions: Data from a Korean multicenter bifurcation registry

BACKGROUND although intravascular ultrasound (IVUS) has been widely used for complex lesions during coronary intervention, IVUS for stenting at bifurcation lesions has not been sufficiently assessed. The aim of this study was to investigate the impact of IVUS guidance on long-term clinical outcomes during drug-eluting stent (DES) implantation for bifurcation lesions. METHODS the Korean multicenter bifurcation registry listed 1,668 patients with non-left main de novo bifurcation lesions who underwent DES implantation between January 2004 and June 2006. Using propensity score matching with clinical and angiographic characteristics, 487 patients with IVUS guidance and 487 patients with angiography guidance were selected. The long-term clinical outcomes were compared between the 2 groups. RESULTS baseline clinical and angiographic characteristics were well matched and showed no significant differences between the 2 groups. Two-stent technique and final kissing ballooning angioplasty were more frequently performed in the IVUS-guided group. Maximal stent diameters at both the main vessel and the side branch were larger in the IVUS-guided group. Periprocedural creatine kinase-MB elevation (>3 times of upper normal limits) was frequently observed in the angiography-guided group. The incidence of death or myocardial infarction was significantly lower in the IVUS-guided group compared to the angiography-guided group (3.8% vs 7.8%, log rank test P = .03, hazard ratio 0.44, 95% CI 0.12-0.96, Cox model P = .04). CONCLUSIONS intravascular ultrasound guidance during DES implantation at bifurcation lesions may be helpful to improve long-term clinical outcomes by reducing the occurrence of death or myocardial infarction.

Modified T-stenting with intentional protrusion of the side-branch stent within the main vessel stent to ensure ostial coverage and facilitate final kissing balloon: The T-stenting and small protrusion technique (TAP-stenting). Report of bench testing and first clinical Italian-Korean two-centre experience†

To describe a novel modification of the T‐stenting technique and to report the bench test as well as the first clinical results obtained.

Frequency of Myocardial Infarction and Its Relationship to Angiographic Collateral Flow in Territories Supplied by Chronically Occluded Coronary Arteries

Background— Despite complete interruption of antegrade coronary artery flow in the setting of a chronic total occlusion (CTO), clinical recognition of myocardial infarction is often challenging. Using cardiac MRI, we investigated the frequency and extent of myocardial infarction in patients with CTO, and assessed their relationship with regional systolic function and the extent of angiographic collateral flow. Methods and Results— We included 170 consecutive patients (median age, 62 years) with angiographically documented CTO. Regional late gadolinium enhancement and wall motion score index were assessed by cardiac MRI with the use of a 17-segment model. Angiographic collateral flow was assessed by the collateral connection grade and the Rentrop score. Evidence of previous myocardial infarction was found in 25% of patients by ECG Q waves, in 69% by regional wall motion abnormality, and in 86% of patients by late gadolinium enhancement. Increased angiographic collateral flow was associated with a lower frequency of Q waves on ECG, and a lower regional wall motion score index, late gadolinium enhancement volume (%), and degree of late gadolinium enhancement transmurality (all P<0.001), as well. Conclusions— The frequency of myocardial infarction in territories subtended by CTO is significantly higher than previously recognized. The degree of myocardial injury downstream epicardial CTO is inversely correlated with the degree of angiographic collaterals.