Doo Sun Sim

Value of Early Risk Stratification Using Hemoglobin Level and Neutrophil-to-Lymphocyte Ratio in Patients With ST-Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

Complete blood count is the most widely available laboratory datum in the early in-hospital period after ST-elevation myocardial infarction (STEMI). We assessed the clinical utility of the combined use of hemoglobin (Hb) level and neutrophil-to-lymphocyte ratio (N/L) for early risk stratification in patients with STEMI. We analyzed 801 consecutive patients with STEMI treated with primary percutaneous coronary intervention (PCI) within 12 hours of onset of symptoms. Patients with cardiogenic shock or underlying malignancy were excluded, and 739 patients (63 ± 13 years, 74% men) were included in the final analysis. Patients were categorized into 3 groups using the median value of N/L (3.86) and the presence of anemia (Hb <13 mg/dl in men and <12 mg/dl in women); group I had low N/L and no anemia (n = 272), group II had low N/L and anemia, or high N/L and no anemia (n = 331), and group III had high N/L and anemia (n = 136). There were significant differences on clinical outcomes during 6-month follow-up among the 3 groups. Prognostic discriminatory capacity of combined use of Hb level and N/L was also significant in high-risk subgroups such as patients with advanced age, diabetes mellitus, multivessel coronary disease, low ejection fraction, and even in those having higher mortality risk based on Thrombolysis In Myocardial Infarction risk score. In a Cox proportional hazards model, after adjusting for multiple covariates, group III had higher mortality at 6 months (hazard ratio 5.6, 95% confidence interval 1.1 to 27.9, p = 0.036) compared to group I. In conclusion, combined use of Hb level and N/L provides valuable timely information for early risk stratification in patients with STEMI undergoing primary PCI.

Plaque Characteristics in Culprit Lesions and Inflammatory Status in Diabetic Acute Coronary Syndrome Patients

OBJECTIVES The aim of this study was to assess the plaque characteristics in culprit lesions in diabetic patients with acute coronary syndrome (ACS). BACKGROUND Data of the relationship between diabetes mellitus and plaque characteristics in patients with ACS are lacking. METHODS We performed grayscale intravascular ultrasound (IVUS) analysis in 422 ACS patients and virtual histology (VH)-IVUS in 310 ACS patients. By subgroup analysis, 112 patients with acute myocardial infarction (AMI) with plaque ruptures also were evaluated. RESULTS In the diabetic subgroup, high-sensitivity C-reactive protein (hs-CRP) was significantly increased (p = 0.008), multivessel disease was more common (65% vs. 29%, p < 0.001), and plaque burden was greater (79.7 +/- 9.8 mm2 vs. 74.2 +/- 8.9 mm2, p < 0.001). In the subgroup analysis of 112 AMI patients with plaque ruptures, the presence of multiple plaque ruptures (60% vs. 29%, p = 0.001) and thrombus (72% vs. 52%, p = 0.032) were more common in diabetic group. Diabetes mellitus was the independent predictor of hs-CRP elevation (odds ratio [OR]: 3.030, 95% confidence interval [CI]: 1.204 to 7.623, p = 0.019), and multiple plaque ruptures (OR: 2.984, 95% CI: 1.311 to 6.792, p = 0.009) by multivariable analysis. In 310 VH-IVUS subsets, the absolute and percent necrotic core volumes were significantly greater (16.9 +/- 15.1 mm3 vs. 11.5 +/- 11.4 mm3, p < 0.001, and 17.3 +/- 9.4% vs. 13.7 +/- 7.5%, p < 0.001, respectively), and the presence of at least one thin-cap fibroatheroma (TCFA) (60% vs. 42%, p = 0.003) and multiple TCFAs (28% vs. 11%, p < 0.001) were more common in the diabetic group. Diabetes mellitus was the only independent predictor of TCFA by multivariable analysis (OR: 2.139, 95% CI: 1.266 to 3.613, p = 0.004). CONCLUSIONS Diabetic patients with ACS have more plaques with characteristics of plaque vulnerability, different composition of plaques, and have increased inflammatory status compared with nondiabetic patients with ACS.

Differences in Clinical Outcomes Between Patients With ST-Elevation Versus Non-ST-Elevation Acute Myocardial Infarction in Korea.

In Korea, the incidence of acute myocardial infarction has been increasing rapidly. Twelve-month clinical outcomes for 13,133 patients with acute myocardial infarction enrolled in the nationwide prospective Korea Acute Myocardial Infarction Registry study were analyzed according to the presence or absence of ST-segment elevation. Patients with ST-segment elevation myocardial infarction (STEMI) were younger, more likely to be men and smokers, and had poorer left ventricular function with a higher incidence of cardiac death compared to patients with non-ST-segment elevation myocardial infarction (NSTEMI). NSTEMI patients had a higher prevalence of 3-vessel and left main coronary artery disease with complex lesions, and were more likely to have co-morbidities. The in-hospital and 1-month survival rates were higher in NSTEMI patients than in STEMI patients. However, 12-month survival rates was not different between the two groups. In conclusion, NSTEMI patients have worse clinical outcomes than STEMI patients, and therefore should be treated more intensively during clinical follow-up.

Plaque Prolapse After Stent Implantation in Patients With Acute Myocardial Infarction: An Intravascular Ultrasound Analysis

OBJECTIVES The aim of this study was to assess the incidence, predictors, and outcome of plaque prolapse (PP) after stent implantation in acute myocardial infarction. BACKGROUND The imaging characteristics of PP in patients with acute myocardial infarction are not well known. METHODS Intravascular ultrasound (IVUS) imaging was performed in 310 patients immediately following stenting for their first acute myocardial infarction. Multiple clinical, angiographic and IVUS derived variables were compared among patients with and without intrastent PP. RESULTS The PP was detected in 27% of the 310 lesions examined. Stent length was longer (31 +/- 13 mm vs. 21 +/- 8 mm, p < 0.001), and positive remodeling (48% vs. 32%, p = 0.008), plaque rupture (51% vs. 31%, p = 0.001), and thrombus (40% vs. 21%, p = 0.001) were significantly more common in PP lesions compared with non-PP lesions. The creatine kinase-myocardial band (CK-MB) was significantly greater after stenting in PP lesions compared with non-PP lesions (Delta = +12.3 +/- 32.0 U/l vs. -4.9 +/- 46.1 U/l, p = 0.002). During a 1-month follow-up, the incidence of stent thrombosis was not significantly different between PP and non-PP lesions [2/85 (2.4%) vs. 2/225 (0.9%), p = 0.308]. Multivariate analysis showed that PP (odds ratio [OR]: 7.34, p < 0.001), plaque rupture (OR: 1.95, p = 0.023), and thrombus (OR: 1.84, p = 0.026) were independently associated with post-stenting CK-MB elevation, and stent length (OR: 2.39, p = 0.003), plaque rupture (OR: 1.96, p = 0.015), and positive remodeling (OR: 1.72, p = 0.044) were independently associated with the development of PP. CONCLUSIONS PP occurs in one-fourth of infarct-related arteries after stent implantation. Lesion characteristics such as plaque rupture and positive remodeling, together with longer stent predict PP. Although long-term follow-up is pending, PP is associated with more myonecrosis after stenting in patients with acute myocardial infarction.

Clinical outcomes and optimal treatment for stent fracture after drug-eluting stent implantation.

BACKGROUND Many studies have suggested that in the era of drug-eluting stents (DES) one of the causes of in-stent restenosis is stent fracture (SF). Yet there have been few studies of the major adverse cardiac events and treatment of DES SF. METHODS AND RESULTS From September 2003 to May 2008, 3365 patients received successful stent implantation with DES, of whom 1009 patients underwent a follow-up coronary angiography irrespective of symptoms. Seventeen SFs were detected in 15/1009 patients (1.5%). All SF patients were continued on medication with combination antiplatelet therapy, regardless of angina symptoms. If in-stent restenosis at the fractured site was significant, we performed coronary interventions even in patients without ischemic symptoms. Patients were treated with heterogenous DES for restenosis lesions (5/8 patients), and the rest were treated with either homogenous DES (2 patients), or plain old balloon angioplasty (1 patient) or medical treatment (7 patients). None of the SF patients suffered from cardiac death during a follow-up period of 20.4+/-12.3 months. CONCLUSION If patients with SF were continued on combination antiplatelet therapy irrespective of ischemic symptoms, there would occur a low rate of major adverse cardiac events, especially cardiac death associated with SF.

Current management of acute myocardial infarction: experience from the Korea Acute Myocardial Infarction Registry.

The Korea Acute Myocardial Infarction Registry (KAMIR) was the first nationwide, population-based, multicenter data collection registry in Korea designed to track outcomes of patients presenting with acute myocardial infarction (AMI). The registry included 51 community and teaching hospitals and contained data on 14,870 patients through January 2008. Patients with non-ST-elevation myocardial infarction had a higher prevalence of co-morbidities and worse outcome than patients with ST-elevation myocardial infarction after being discharged from hospital, emphasizing the need for aggressive outpatient management of these patients. Risk factors and prognosis after AMI were similar to those in other registries from the West. A number of innovative approaches have been implemented in numerous studies generated by the KAMIR and have set standards of care for AMI in the Korean population.

Differences in intravascular ultrasound findings in culprit lesions in infarct-related arteries between ST segment elevation myocardial infarction and non-ST segment elevation myocardial infarction.

BACKGROUND Previous studies have reported diffuse destabilization of atherosclerotic plaques in acute myocardial infarction (AMI). We used intravascular ultrasound (IVUS) to assess coronary culprit lesions in ST segment elevation MI (STEMI) vs. in non-ST segment elevation MI (NSTEMI). METHODS Patient population comprised 125 STEMI and 185 NSTEMI patients. IVUS findings included ruptured plaque (a cavity that communicated with the lumen with an overlying residual fibrous cap fragment), lipid-pool like image (a pooling of hypoechoic or echolucent material covered with a hyperechoic layer), thrombus (discrete intraluminal filling defects), and plaque prolapse (tissue extrusion through the stent strut at post-stenting). RESULTS Culprit lesions had larger external elastic membrane area (13.5+/-4.9mm(2) vs. 11.9+/-4.3mm(2), p=0.002), larger plaque plus media area (10.8+/-4.4mm(2) vs. 9.1+/-4.1mm(2), p=0.001), and greater plaque burden (78.7+/-10.1% vs. 74.8+/-12.0%, p=0.002), and smaller culprit lesion site calcium arc (96+/-90 degrees vs. 153+/-114 degrees , p=0.002) in patients with STEMI than in those with NSTEMI. Culprit lesion plaque ruptures, lipid-pool like images, and thrombus were observed more frequently in patients with STEMI than in those with NSTEMI (46% vs. 29%, p=0.002; 39% vs. 25%, p=0.010; and 34% vs. 21%, p=0.006, respectively). Culprit lesions were more predominantly hypoechoic in patients with STEMI than in those with NSTEMI (62% vs. 40%, p<0.001). There was a trend that post-stenting plaque prolapse was observed more frequently in patients with STEMI than in those with NSTEMI (33% vs. 24%, p=0.081). CONCLUSIONS Culprit lesions in STEMI have more markers of plaque instability (more plaque rupture and thrombus, and larger plaque mass) compared with lesions in NSTEMI.

Role of Intravascular Ultrasound in Patients with Acute Myocardial Infarction Undergoing Percutaneous Coronary Intervention

Stent thrombosis and restenosis remain drawbacks of drug-eluting stents in patients with acute myocardial infarction (AMI). Intravascular ultrasound (IVUS) guidance for stent deployment helps optimize its results in stable patients. The aim of this study was to examine the utility of routine IVUS guidance in patients with AMI undergoing percutaneous coronary intervention (PCI). Employing data from Korea Acute Myocardial Infarction Registry (KAMIR), we analyzed 14,329 patients with AMI from April 2006 through September 2010. Patients with cardiogenic shock and rescue PCI after thrombolysis were excluded. Clinical outcomes of 2,127 patients who underwent IVUS-guided PCI were compared to those of 8,235 patients who did not. Mean age was 63.6 ± 13.5 years and 72.3% were men. Patients undergoing IVUS-guided PCI were younger, more often men, more hyperlipemic, and had increased body mass index and left ventricular ejection fraction. Number of treated vessels and stents used, stent length, and stent diameter were increased in the IVUS-guided group. Multivessel involvement was less frequent and American College of Cardiology/American Heart Association type C lesion was more frequent in the IVUS-guided group. Drug-eluting stents were more frequently used compared to bare-metal stents in the IVUS group. There was no significant relation of stent thrombosis between the 2 groups. Twelve-month all-cause death was lower in the IVUS group. After multivariate analysis and propensity score adjustment, IVUS guidance was not an independent predictor for 12-month all-cause death (hazard ratio 0.212, 0.026 to 1.73, p = 0.148). In conclusion, this study does not support routine use of IVUS guidance for stent deployment in patients who present with AMI and undergo PCI.

Plaque components at coronary sites with focal spasm in patients with variant angina: Virtual histology-intravascular ultrasound analysis

BACKGROUND We compared the plaque components at coronary sites with focal spasm after ergonovine provocation test in 30 variant angina (VA) patients with those at culprit coronary sites in 32 unstable angina (UA) patients using virtual histology-intravascular ultrasound (VH-IVUS). METHODS VH-IVUS classified and color-coded tissue into four major components: fibrotic; fibro-fatty; dense calcium (DC); and necrotic core (NC). Thin-cap fibroatheroma (TCFA) was defined as a NC≥10% of plaque area in at least 3 consecutive frames without overlying fibrous tissue in the presence of ≥40% plaque burden. RESULTS The lesion site plaque burden was significantly smaller (44.5±10.8% vs. 70.5±13.1%, p<0.001), the plaque volume was significantly smaller (135±118 mm³ vs. 223±160 mm³, p=0.020), the remodeling index was significantly lower (0.90±0.14 vs. 0.97±0.23, p=0.023), and more plaque was hypoechoic with less calcium (87% vs. 56% and 0% vs. 19%, respectively, p=0.033) in VA patients compared with UA patients. The % NC and DC areas were significantly smaller at the minimum lumen site within spasm/culprit lesion (12.9±12.9% vs. 22.3±11.7%, p=0.004, and 6.5±8.0% vs. 12.8±10.8%, p=0.011, respectively), and the % NC and DC volumes were significantly smaller in VA patients compared with UA patients (12.2±10.3% vs. 17.7±8.1%, p=0.025, and 6.4±6.0% vs. 11.8±8.5%, p=0.007, respectively). The TCFA within lesion segments was less frequently observed in VA patients compared with UA patients (13% vs. 53%, p=0.001). CONCLUSIONS VA patients have less plaque, more negative remodeling behavior, more hypoechoic plaque with less calcification, and less NC- and DC-containing lesions and less TCFA lesions compared with UA patients.

Comparison of Clinical Outcomes of Hydrophilic and Lipophilic Statins in Patients with Acute Myocardial Infarction

Background/Aims A controversy exists about which statin is preferable for patients with acute myocardial infarction (AMI), and clinical impacts of different statins according to lipophilicity have not been established. Methods The 1,124 patients with AMI included in the present study were divided into hydrophilic- and lipophilic-statin groups. In-hospital complications (defined as death, cardiogenic shock, ventricular arrhythmia, infection, bleeding, and renal insufficiency, and other fatal arrhythmias), major adverse cardiac events (MACE), all-cause death, re-myocardial infarction, re-percutaneous coronary intervention (re-PCI), and surgical revascularization were analyzed during a 1-year clinical follow-up. Results Baseline characteristics were similar between the two groups, and in-hospital complication rates showed no between-group differences (11.7% vs. 12.8%, p = 0.688). Although MACE at the 1- and 6-month clinical follow-ups occurred more in hydrophilic statin group I (1 month: 10.0% vs. 4.4%, p = 0.001; 6 month: 19.9% vs. 14.2%, p = 0.022), no significant difference in MACE was observed at the 1-year follow-up (21.5% vs. 17.9%, p = 0.172). Both statin groups showed similar efficacy for reducing serum lipid concentrations. A Cox-regression analysis showed that the use of a hydrophilic statin did not predict 1-year MACE, all-cause death, AMI, or re-PCI. Conclusions Although short-term cardiovascular outcomes were better in the lipophilic-statin group, 1-year outcomes were similar in patients with AMI who were administered hydrophilic and lipophilic statins. In other words, the type of statin did not influence 1-year outcomes in patients with AMI.