Keun-Ho Park

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.

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.

Clinical impact of thrombus aspiration during primary percutaneous coronary intervention: Results from Korea Acute Myocardial Infarction Registry

BACKGROUND The role of thrombus aspiration (TA) as an adjunct to primary percutaneous coronary intervention (PPCI) remains a matter of controversy. METHODS AND RESULTS A total of 2105 patients enrolled in the nationwide prospective Korea Acute Myocardial Infarction Registry, a cohort of 745 (35.4%) patients who underwent TA during PPCI was compared with 1360 (64.6%) patients who underwent conventional PCI without TA. Clinical outcomes at 12-months of overall enrolled patients and subgroups according to key variables were assessed using Cox regression models adjusted by propensity score. Although there was no significant difference among overall patients, in subgroup analyses, administration of glycoprotein (GP) IIb/IIIa inhibitor during PPCI [adjusted hazard ratio (HR) 0.329, 95% confidence interval (CI) 0.126-0.860, p=0.023] and left anterior descending (LAD) as a culprit lesion (adjusted HR 0.516, 95% CI 0.275-0.971, p=0.040) were the settings, in which TA was associated with a lower major adverse cardiac events (MACE) rate compared with non-TA. CONCLUSIONS Although TA does not improve clinical outcomes in overall patients who underwent PPCI, TA for LAD occlusion improves 12-month MACE. Furthermore, use of GP IIb/IIIa inhibitor with TA has a synergistic effect on clinical outcomes.

Relationship between Coronary Artery Calcium Score by Multidetector Computed Tomography and Plaque Components by Virtual Histology Intravascular Ultrasound

The aim of this study was to evaluate the relationship between coronary artery calcium score (CACS) assessed by multidetector computed tomography (MDCT) and plaque components assessed by virtual histology-intravascular ultrasound (VH-IVUS) in 172 coronary artery disease (CAD) patients with 250 coronary lesions. CACS was assessed according to Agatston scoring method by MDCT and patients were divided into four groups: Group I (CACS = 0 [n = 52]); Group II (CACS = 1-100 [n = 99]); Group III (CACS = 101-400 [n = 84]); and Group IV (CACS > 400 [n = 15]). Total atheroma volume was greatest in Group IV (152 ± 132 µL vs 171 ± 114 µL vs 195 ± 149 µL vs 321±182 µL, P < 0.001). The absolute dense calcium (DC) and necrotic core (NC) volumes were greatest, and relative DC volume was greatest in Group IV (5.5 ± 6.6 µL vs 11.0 ± 10.3 µL vs 15.6 ± 13.6 µL vs 36.6 ± 18.2 µL, P < 0.001, and 14.8 ± 18.2 µL vs 19.5 ± 18.9 µL vs 22.5 ± 19.1 µL vs 41.7 ± 27.9 µL, P < 0.001, and 6.4 ± 5.3% vs 11.0 ± 6.2% vs 14.0 ± 6.5% vs 20.0 ± 7.8%, P < 0.001, respectively). The absolute plaque and DC and NC volumes and the relative DC volume correlated positively with calcium score. CAD patients with high calcium score have more vulnerable plaque components (greater DC and NC-containing plaques) than those with low calcium score.

Red cell distribution width as a novel predictor for clinical outcomes in patients with paroxysmal atrial fibrillation.

AIMS Elevated red cell distribution width (RDW) has been known to be associated with adverse long-term outcomes in patients with cardiovascular diseases. We aimed to evaluate relationship between RDW values and clinical outcomes in patients with paroxysmal atrial fibrillation (AF). METHODS AND RESULTS We analysed 567 patients who were newly diagnosed as paroxysmal AF. Clinical outcomes were analysed after median 4.8 (3.4-6.9) years follow-up. The composite clinical outcomes were defined as the composite of death, hospitalization due to heart failure, and new-onset stroke. Bleeding events were composed of major and minor bleeding. The relationship of RDW with clinical outcomes was assessed using continuous or categorical variables as quartiles: <12.8, 12.8-13.2, 13.3-13.8, and ≥13.9%. Patients with the highest RDW quartile were the oldest and had more frequent history of heart failure. CHA2DS2-VASc score was increased along with increasing RDW quartiles (1.75 ± 1.48 vs. 1.77 ± 1.63 vs. 1.87 ± 1.61 vs. 2.33 ± 1.65, P = 0.008). Incidence of new-onset stroke (log-rank P = 0.032), the composite clinical outcomes (log-rank P = 0.014), and bleeding events (log-rank P = 0.001) were increased as increasing RDW quartiles. Multivariate analysis identified that RDW was a significant predictor for new-onset stroke [adjusted hazard ratio (HR) 1.32, 95% confidence interval (CI) 1.06-1.65, P = 0.015], the composite clinical outcomes (adjusted HR 1.21, 95% CI 1.03-1.41, P = 0.017), and bleeding events (adjusted HR 1.36, 95% CI 1.13-1.64, P = 0.001). CONCLUSIONS RDW can be a new, useful, novel predictor of clinical and safety outcomes in patients with paroxysmal AF.

Histopathological Comparison among Biolimus, Zotarolimus and Everolimus-Eluting Stents in Porcine Coronary Restenosis Model.

Background and Objectives The aim of this study was to examine the histolopathogical effects among the biolimus, zotarolimus, and everolimus eluting stent (EES) in the porcine coronary restenosis model. Subjects and Methods Pigs were randomized into three groups in which the coronary arteries (15 pigs, 10 coronaries in each group) had either a biolimus A9 eluting stent (BES, n=10), zotarolimus eluting stent (ZES, n=10) or an EES (n=10). Histopathologic analysis was performed at 28 days after stenting. Results There were no significant differences in the injury score among the three groups. There was a significant difference in the internal elastic lamina, lumen area, neointima area, percent area stenosis, and the fibrin and inflammation score among the three groups (4.3±0.53 mm2, 2.5±0.93 mm2, 1.8±1.03 mm2, 40.7±20.80%, 1.7±0.41, 1.4±0.72 in the BES group vs. 5.1±0.55 mm2, 2.3±1.14 mm2, 2.8±1.00 mm2, 55.4±21.23%, 2.0±0.39, 1.6±0.76 in the ZES group vs. 4.4±0.53 mm2, 1.7±1.22 mm2, 2.8±1.23 mm2, 64.0±26.00%, 1.8±0.76, 2.1±0.90 in the EES group, respectively). BES is more effective in inhibiting neointimal hyperplasia compared to ZES and EES (p<0.0001). According to the fibrin and inflammation score, BES and EES are more effective in decreasing the fibrin deposition compared to ZES (p<0.001). Moreover, BES and ZES are more effective in reducing the inflammatory reaction compared to EES (p<0.001). Conclusion The result demonstrates that BES shows better histopathological characteristics than ZES and EES at one month after stenting in the porcine coronary restenosis model.

What is the optimal duration of triple anti-platelet therapy in patients with acute myocardial infarction undergoing drug-eluting stent implantation?

BACKGROUND The optimal duration of triple anti-platelet therapy (DTAP) remains unclear in patients with acute myocardial infarction (AMI). METHODS We retrospectively analyzed 716 AMI patients who received TAP (aspirin, clopidogrel, and cilostazol) after drug-eluting stent (DES) implantation from November 2005 to May 2008. Mean age was 61.9 ± 11.70 years (male gender 74.1%) and mean duration of TAP was 98.1 ± 115.34 days. We compared the major adverse cardiovascular events [MACE, defined as the composite of cardiac death, non-fatal AMI, stent thrombosis, and target vessel revascularization (TVR)] between the group of DTAP ≥ 3 months (n = 497) and those of < 3 months (n = 219). RESULTS There were no significant differences in the incidences of cardiac death, non-fatal AMI, stent thrombosis, and TVR at 1-year follow-up between the two groups. However, the group of DTAP ≥ 3 months had lower incidence of MACE than those < 3 months (5.9% vs. 10.7%, p = 0.044). The rate of bleeding complications was similar between the two groups. By Cox regression analysis with propensity score adjustment, Killip class IV and DTAP ≥ 3 months were independent predictors of 1-year MACE [hazard ratio (HR) = 10.417; 95% confidence interval (CI) = 1.587-68.377, p = 0.015 and HR = 0.508; 95% CI = 0.269-0.956, p = 0.036]. CONCLUSIONS Our data show that the DTAP ≥ 3 months is associated with better clinical outcomes compared with that of < 3 months in patients with AMI undergoing DES implantation without increasing bleeding complications.

Comparison of peri-procedural platelet inhibition with prasugrel versus adjunctive cilostazol to dual anti-platelet therapy in patients with ST segment elevation myocardial infarction.

BACKGROUND It has been well known that the inhibition of platelet aggregation (IPA) by anti-platelet agents was important to reduce the thrombo-embolic events in patients with ST segment elevation myocardial infarction (STEMI). However, the peri-procedural IPA by anti-platelet agents was not well known. METHODS We compared the peri-procedural IPA between prasugrel and adjunctive cilostazol to dual anti-platelet therapy (triple anti-platelet therapy; TAP) in patients with STEMI undergoing primary percutaneous coronary intervention (PCI). We prospectively randomized 70 consecutive clopidogrel-naive patients with STEMI planned PCI to either prasugrel [loading dose (LD) 60 mg; 37 patients] or TAP (LD aspirin 300 mg, clopidogrel 600 mg, and cilostazol 200mg; 33 patients). Primary end points of the study were the platelet reactivity unit (PRU) or % inhibition by the VerifyNow P2Y12 assay at pre-PCI and pre-discharge. RESULTS The drug loading to pre-PCI time was similar between prasugrel and TAP groups (25.4 ± 10.42 min vs. 25.5 ± 10.56 min, p=0.957). PRU at pre-PCI was significantly lower in prasugrel than in TAP (269.1 ± 71.69 vs. 306.5 ± 48.67, p=0.012). The lower PRU and greater % inhibition also observed in prasugrel than in TAP at pre-discharge (108.2 ± 60.51 vs. 238.1 ± 73.40; 63.6 ± 18.51% vs. 16.8 ± 17.91%, p<0.001 respectively). No differences in in-hospital bleeding complications between the two groups were observed. CONCLUSION Our study demonstrates that prasugrel could produce a significantly greater peri-procedural as well as in-hospital IPA compared with TAP in patients with STEMI undergoing primary PCI.

Efficacy of Triple Anti-Platelet Therapy Including Cilostazol in Acute Myocardial Infarction Patients Undergoing Drug-Eluting Stent Implantation

Background and Objectives Triple anti-platelet therapy is known to prevent restenosis after drug-eluting stent (DES) implantation. However, there is little available data concerning the efficacy of triple anti-platelet therapy for acute myocardial infarction (AMI). Subjects and Methods We analyzed 528 consecutive patients with AMI undergoing DES implantation between Nov 2005 and Apr 2008. We compared clinical outcomes in the triple anti-platelet therapy (group I, n=413: cilostazol combined with aspirin and clopidogrel for at least one month) and dual antiplatelet therapy groups (group II, n=115: aspirin and clopidogrel). Results There were no significant differences in baseline characteristics. However, ST elevation myocardial infarction (STEMI) and use of TAXUS® stents were more common (70.9% vs. 55.7%, p=0.002; 83.5% vs. 73.0%, p=0.011) in Group I. Group I had lower incidences of cardiac death, 6-month target lesion revascularization (TLR), and major adverse cardiac and cerebrovascular events (MACCE) compared to Group II (1.7% vs. 5.7%, p=0.022; 5.7% vs. 11.5%, 0.035; 7.9% vs. 16.0%, p=0.011). On subgroup analysis, the incidence of 6-month TLR was lower among patients with American College of Cardiology/American Heart Association (ACC/AHA) B2 or C lesions and non-STEMI (6.0% vs. 14.9%, p=0.012; 4.3% vs. 19.1%, p=0.002) in Group I compared to those in Group II. The rates of bleeding complications were no different between the two groups. On multivariate analysis, Killip III or IV and triple anti-platelet therapy were independent predictors of 6-month MACCE {hazard ratio (HR)=3.382; 95% confidence interval (CI)=1.384-8.262, HR=0.436; 95% CI=0.203-0.933}. Conclusion Triple anti-platelet therapy is safe and efficacious, and it prevents TLR in patients with AMI, especially those with complex lesions and non-STEMIs.

Benefit of statin therapy in patients with coronary spasm-induced acute myocardial infarction

BACKGROUND Coronary artery spasm is associated with vascular smooth muscle hyper-reactivity. Statins suppress coronary spasm by inhibiting the vascular smooth muscle contraction. However, it is unclear whether statin therapy benefits patients with coronary spasm-induced acute myocardial infarction (AMI). METHODS AND RESULTS We analyzed 501 (median age 57 years; male/female, 346/155) patients with coronary spasm-induced AMI with nonobstructive coronary arteries (stenosis severity <50%) from the Korea AMI Registry between November 2005 and October 2013. They were divided into two groups according to statin prescription at discharge (statin group n=292; nonstatin group n=209). The primary endpoint was the composite of 12-month major adverse cardiac events, including all causes of death, non-fatal myocardial infarction, and target vessel revascularization. The primary endpoint occurred in 17 patients during 12 months of follow-up. Statin therapy significantly reduced the risk of the composite primary endpoint [adjusted hazard ratio (HR): 0.30; 95% confidence interval (CI): 0.09-0.97; p=0.045]. Statin therapy reduced the risk of myocardial infarction (HR: 0.19; 95% CI: 0.04-0.93; p=0.040). However, we found no significant difference in the risk of the composite of all-cause death. CONCLUSION Statin therapy in patients with coronary spasm-induced AMI with nonobstructive coronary arteries was associated with improved clinical outcome, which was predominantly accounted for by reducing the incidence of myocardial infarction.