Myeong Kon Kim

Quantification of regional calcium burden in chronic total occlusion by 64-slice multi-detector computed tomography and procedural outcomes of percutaneous coronary intervention

BACKGROUND One of the most important reasons for failure of percutaneous coronary intervention (PCI) in chronic total occlusion (CTO) is calcified plaque, which either prevents passage of guide wire or ruptures after balloon inflation. We sought to evaluate whether quantified calcium contents of CTO on multi-detector computed tomography (MDCT) correlate with immediate procedural outcomes. METHODS Sixty-four patients with 72 CTO lesions who underwent 64-slice MDCT prior to PCI were investigated. The lesions were divided into 2 groups according to procedural outcomes (55 lesions with PCI-success group, 17 lesions with PCI-failure group). Clinical, angiographic and MDCT parameters, including regional calcium volume (RCaV), regional calcium score (RCaS), regional calcium equivalent mass (RCaEq), and relative calcium area at the most calcified cross section of CTO (%CaS/CSA), were compared between the two groups. RESULTS The duration of CTO was shorter in PCI-success group than PCI-failure group (7.16 ± 10.5 vs 15.59 ± 14.92 months, p=0.011), and the procedural success rate was 76.3%. Regional calcium-related parameters (RCaV 52.86 ± 58.39 vs 7.26 ± 15.27 mm(3), p<0.001; RCaS 72.71 ± 78.4 vs 9.66 ± 20.2, p<0.001; RCaEq 12.58 ± 12.97 vs 1.84 ± 3.716 mgCaHA, p<0.001; %CaS/CSA 53.9 ± 20.3 vs 30.4 ± 17.1%, p=0.009) in the occluded segment were higher and the occlusion length was longer (37.44 ± 27.48 vs 22.00 ± 18.04 mm, p<0.021) in PCI-failure group compared to PCI-success group. Multivariate regression analysis showed that only %CaS/CSA was a significant determinant of PCI-failure. CONCLUSIONS Precise quantification of regional calcification and measurement of the occluded segment by high resolution MDCT can deliver important information for predicting procedural outcomes in PCI of CTO.

Preventive Effects of Exenatide on Endothelial Dysfunction Induced by Ischemia-Reperfusion Injury via KATP Channels

Objective—The purpose of this study was to evaluate whether exenatide administration can prevent impairment in endothelium-dependent vasodilatation induced by ischemia-reperfusion (IR) injury and whether this effect is mediated by KATP channel opening. Methods and Results—In a double-blind, placebo-controlled, crossover design, 20 volunteers were randomly assigned to 2 groups: subcutaneous exenatide (10 &mgr;g) or placebo administration. At 30 minutes after the study drug administration, endothelium-dependent flow-mediated dilatation (FMD) of the radial artery was measured before and after IR (15 minutes of ischemia at the level of the brachial artery followed by 15 minutes of reperfusion) injury. Seven days later, both groups were crossed over and received the other treatment (ie, placebo or exenatide) and underwent the same protocol. Pre-IR radial artery diameter, FMD, and baseline radial artery diameter after IR injury were similar between 2 groups (P=no significant difference). After placebo administration, IR significantly blunted FMD (before IR: 12.0±6.23%; after IR: 4.6±3.57%, P=0.02). Exenatide prevented this impairment (FMD before IR: 15.0±7.14%; FMD after IR: 15.0±5.96%, P=no significant difference; P<0.001 compared with placebo). In a separate protocol, this protective effect was completely abolished by pretreatment with glibenclamide (glyburide, 5 mg), a blocker of KATP channels (n=7; FMD before IR: 12.0±2.2%; after IR: 3.2±2.1%, P<0.001). Conclusion—The present study demonstrates that subcutaneous exenatide protects IR-induced endothelial dysfunction through opening of KATP channels in human IR injury model.

Analysis of prognostic factors for postoperative bleeding after tonsillectomy

Postoperative bleeding is the most frequent surgical complication after tonsillectomy and may be associated with increased mortality rate. We have, therefore, analyzed factors associated with and prognostic for bleeding after tonsillectomy. The 2,254 patients who underwent tonsillectomy under general anesthesia at our institution from January 2005 to December 2009 were divided into bleeding and non-bleeding groups, and their demographic and clinical characteristics were compared. Age, administration of steroid immediately after general anesthesia, absence of administration of non-steroidal anti-inflammatory drugs, and the surgeon’s experience were significantly associated with bleeding. In contrast, gender, chief complaints, performance of associated surgery, and type of anesthetic were not associated with postoperative bleeding. Hemorrhage after tonsillectomy was associated with the administration of steroids and with the non-administration of non-steroidal anti-inflammatory drugs.

Association between a promoter polymorphism (rs2192752, –1028A/C) of interleukin 1 receptor, type I (IL1R1) and location of papillary thyroid carcinoma in a Korean population

The interleukin 1 receptor, type I (IL1R1) is important in the pathogenesis of cancer. We investigated whether single nucleotide polymorphisms (SNPs) of IL1R1 contribute to the development of papillary thyroid carcinoma (PTC), in addition to the clinicopathological features such as the size, number, location, extrathyroidal invasion and metastasis of PTC. Three promoter SNPs (rs949963 −615G/A, rs2192752 −1028A/C and rs3917225 −1099A/G) in IL1R1 were genotyped using direct sequencing in 118 patients with PTC and 347 controls. The odds ratio (OR), 95% confidence interval (CI) and P value were analysed using SNPStats and SNPAnalyzer Pro. For the exact results, Fisher’s exact test and Bonferroni correction (Pc) were performed. The three promoter SNPs of IL1R1 were not associated with PTC development. For the clinicopathological features of PTC, rs2192752 was associated with location (one lobe versus both lobes): dominant model, OR = 3.11, 95% CI = 1.39–6.96, Pc = 0.015; log‐additive model, OR = 2.79, 95% CI = 1.38–5.66, Pc = 0.0087. The C allele frequency of rs2192752 was higher in the both lobes group (28.0%) than the one lobe group (12.3%) (OR = 2.77, 95% CI = 1.40–5.48, Pc = 0.009). However, rs949963 and rs3917225 were not correlated with clinicopathological features including location of PTC. The IL1R1 promoter SNP rs2192752 may contribute to the location of PTC, and the C allele of rs2192752 may be a risk factor for the development of PTC in both lobes.

Effect of cilostazol addition or clopidogrel doubling on platelet function profiles in diabetic patients undergoing a percutaneous coronary intervention.

BackgroundWe investigated the pharmacodynamic effect of cilostazol addition (100 mg twice, Triple) or clopidogrel doubling (150 mg daily, Double) on standard dual antiplatelet therapy in type 2 diabetes mellitus (T2DM) patients with clopidogrel resistance undergoing a percutaneous coronary intervention. Methods and resultsThis was a prospective, randomized, cross-over platelet function study. Percent inhibition less than 20% was used as the cutoff value of clopidogrel resistance. After percutaneous coronary intervention, a total of 50 T2DM patients with clopidogrel resistance were assigned to receive cilostazol 100 mg twice daily or clopidogrel 150 mg daily for 28 days; afterwards, they received cross-over treatment for another 28 days. Eight patients were excluded because of side effects and follow-up loss. The platelet function test using VerifyNow was performed at three time points: at baseline (T0), 28 days after randomization (T1), and 28 days after cross-over treatment (T2).A total of 42 T2DM patients completed the study protocol. The clopidogrel resistance improved significantly following cilostazol addition or clopidogrel doubling treatment compared with baseline (52.9±27.0 in Triple, 45.4±16.8% in Double, P<0.001 in both). This effect continued after cross-over treatment (58.1±26.1 and 41.0±20.0%, respectively, both P<0.05). A head-to-head comparison between two groups showed a lower P2Y12 reaction unit (PRU) and higher percentage of platelet inhibition in the Triple than those in the Double group (PRU, 138.7±88.2 vs. 198.8±19.5, P=0.049; %platelet inhibition, 58.1±26.1 vs. 40.97±20.0, P=0.048). ConclusionAdjunctive treatment with cilostazol in T2DM patients on standard dual antiplatelet therapy might be a more effective strategy for overcoming clopidogrel resistance than clopidogrel doubling treatment.

The effect of intrathecal fentanyl on Cerebral State Index-guided sedation during spinal anaesthesia*

This study investigated the effect of intrathecal fentanyl on the dose of propofol during sedation guided by Cerebral State Index monitoring. Seventy patients were randomly assigned to receive either fentanyl 25 μg (n = 35) or normal saline (n = 35) with hyperbaric bupivacaine 12.5 mg for spinal anaesthesia. Propofol was infused to maintain a Cerebral State Index value of 65–75 for 30 min. The propofol infusion time and dose required to reach a Cerebral State Index value of 75 were recorded together with the time required to reach a Cerebral State Index value higher than 90 after cessation of sedation. The onset time for sedation was faster and the recovery time was slower in the fentanyl group compared to those in the saline group (p = 0.018 and 0.027, respectively). The propofol doses required for onset and maintenance of sedation were significantly lower in the fentanyl group compared to those in the control group (p = 0.018 and < 0.001, respectively). In conclusion, adding intrathecal fentanyl 25 μg during spinal anaesthesia significantly reduced the dose of propofol required for sedation and prolonged the subsequent recovery time.

Combined Assessments of Biochemical Markers and ST-Segment Resolution Provide Additional Prognostic Information for Patients With ST-Segment Elevation Myocardial Infarction.

Background and Objectives The prognostic value of biochemical markers and the resolution of ST-segment elevation on electrocardiogram are well established. However, how a combination of these two tools affects the evaluation of risk stratification has not yet been evaluated. Subjects and Methods Between January 2006 and June 2008, 178 consecutive patients treated with primary percutaneous coronary interventions after ST-segment elevation myocardial infarctions (STEMI) were analyzed at two coronary care units. Patients were divided into the following three groups according to ST-segment resolution: complete (≥70% depression of the elevated ST-segment, n=63), partial (30% to 70%, n=90), and incomplete (<30%, n=25). Demographic data, including history, electrocardiography, biochemical markers, initial ejection fraction, and angiographic findings were also evaluated. Results There were 7 deaths, 3 repeated myocardial infarctions, and 17 readmissions for worsening heart failure during six months of follow-up. In a multivariate analysis to predict clinical outcomes, ejection fraction {hazard ratio (HR): 0.83 (0.76-0.91), p<0.01}, high-sensitivity C-reactive protein {HR: 1.15 (1.05-1.26), p<0.05}, and the degree of ST-segment resolution {HR: 0.96 (0.93-0.09), p<0.05} were independently associated with clinical outcomes. According to the Cox-proportional hazards model, the addition of ST-segment resolution markedly improved the prognostic utility of the model containing biochemical markers and ejection fraction. Conclusion Assessment of biomarkers upon admission and ST-segment resolution are strong predictors of clinical outcomes. The combination of these data provides additive information about prognosis at an early point in the disease progression and further improves risk stratification for STEMI.

Valsartan 160 mg/Amlodipine 5 mg Combination Therapy versus Amlodipine 10 mg in Hypertensive Patients with Inadequate Response to Amlodipine 5 mg Monotherapy

Background and Objectives When monotherapy is inadequate for blood pressure control, the next step is either to continue monotherapy in increased doses or to add another antihypertensive agent. However, direct comparison of double-dose monotherapy versus combination therapy has rarely been done. The objective of this study is to compare 10 mg of amlodipine with an amlodipine/valsartan 5/160 mg combination in patients whose blood pressure control is inadequate with amlodipine 5 mg. Subjects and Methods This study was conducted as a multicenter, open-label, randomized controlled trial. Men and women aged 20-80 who were diagnosed as having hypertension, who had been on amlodipine 5 mg monotherapy for at least 4 weeks, and whose daytime mean systolic blood pressure (SBP) ≥135 mmHg or diastolic blood pressure (DBP) ≥85 mmHg on 24-hour ambulatory blood pressure monitoring (ABPM) were randomized to amlodipine (A) 10 mg or amlodipine/valsartan (AV) 5/160 mg group. Follow-up 24-hour ABPM was done at 8 weeks after randomization. Results Baseline clinical characteristics did not differ between the 2 groups. Ambulatory blood pressure reduction was significantly greater in the AV group compared with the A group (daytime mean SBP change: -14±11 vs. -9±9 mmHg, p<0.001, 24-hour mean SBP change: -13±10 vs. -8±8 mmHg, p<0.0001). Drug-related adverse events also did not differ significantly (A:AV, 6.5 vs. 4.5 %, p=0.56). Conclusion Amlodipine/valsartan 5/160 mg combination was more efficacious than amlodipine 10 mg in hypertensive patients in whom monotherapy of amlodipine 5 mg had failed.

PREVENTIVE EFFECT OF EXENATIDE TO ENDOTHELIAL DYSFUNCTION INDUCED BY ISCHEMIA-REPERFUSION INJURY VIA ADP K CHANNELS

Background_Animal studies have demonstrated that administration of exenatide can limit myocardial damage induced by prolonged ischemia, an effect that appears to be mediated by opening of adenosine triphosphate-sensitive potassium(KATP) channels. No study has investigated whether exenatide can also prevent the impairment in endothelium-dependent vasodilatation induced by ischemia-reperfusion (IR) in humans.