Dong-Ju Choi

Physiological evaluation of the provisional side-branch intervention strategy for bifurcation lesions using fractional flow reserve

AIMS This study was performed to evaluate the functional outcomes of fractional flow reserve (FFR)-guided jailed side-branch (SB) intervention strategy. METHODS AND RESULTS One hundred and ten patients treated by provisional strategy were consecutively enrolled and SB FFR was measured in 91 patients. SB intervention was allowed when FFR was <0.75. FFR measurement was repeated after SB intervention and at 6-month follow-up angiography. In 26 of 28 SB lesions with FFR <0.75, balloon angioplasty (SB balloon/artery ratio = 0.84 +/- 0.14) was performed and FFR >or=0.75 was achieved in 92% of the lesions although the mean residual stenosis was 69 +/- 10%. During follow-up, there were no changes in SB FFR in lesions with (0.86 +/- 0.05 to 0.84 +/- 0.01, P = 0.4) and without SB angioplasty (0.87 +/- 0.06 to 0.89 +/- 0.07, P = 0.1). Functional restenosis (FFR <0.75) rate was only 8% (5/65). When clinical outcomes of these patients were compared with 110 patients with similar bifurcation lesions treated without FFR-guidance, there was no difference in 9-month cardiac event rates (4.6 vs. 3.7%, P = 0.7) between the two groups. CONCLUSION In conclusion, FFR-guided SB intervention strategy resulted in good functional outcomes.

Prevention of radiocontrast medium-induced nephropathy using short-term high-dose simvastatin in patients with renal insufficiency undergoing coronary angiography (PROMISS) trial--a randomized controlled study

BACKGROUND Contrast media cause oxidative stress, which has been suggested as one possible mechanism responsible for contrast-induced nephropathy. Statins appear to have pleiotropic effects, including antioxidant properties. We investigated to determine whether simvastatin pretreatment reduces the risk of contrast-induced nephropathy in a high-risk population of patients with renal insufficiency undergoing coronary angiography. METHODS We conducted a prospective, randomized, double-blind, placebo-controlled, 2-center trial, involving 247 consecutive patients with chronic renal insufficiency (calculated creatinine clearance < or = 60 mL/min and/or serum creatinine > or = 1.1 mg/dL) undergoing coronary angiography. Patients were randomized to simvastatin (n = 124; 160 mg total, 40 mg orally every 12 hours starting the evening before and ending the morning after the procedure) or placebo (n = 123). All patients received pre - and postprocedure hydration. The iso-osmolar contrast agent iodixanol was used for coronary angiography in all patients. RESULTS There was no difference between simvastatin and placebo in mean peak increase in serum creatinine measured within 48 hours after coronary angiography, the primary study end point (0.002 +/- 0.164 vs 0.017 +/- 0.230 mg/mL respectively, P = .559). The incidence of contrast-induced nephropathy, a secondary end point defined as increase of either > or = 25% or > or = 0.5 mg/dL in serum creatinine, was 2.5% in simvastatin-treated patients (3/118) and 3.4% in placebo-treated patients (4/118), a nonsignificant difference (P = 1.00). There were also no differences between the 2 groups in length of hospital stay or 1- and 6-month clinical outcomes. CONCLUSIONS Simvastatin pretreatment for short-term at high dose do not prevent renal function deterioration after administration of contrast medium in patients with baseline renal insufficiency undergoing coronary angiography.

Anatomic and Functional Evaluation of Bifurcation Lesions Undergoing Percutaneous Coronary Intervention

Background—We sought to investigate the mechanism of geometric changes after main branch (MB) stent implantation and to identify the predictors of functionally significant “jailed” side branch (SB) lesions. Methods and Results—Seventy-seven patients with bifurcation lesions were prospectively enrolled from 8 centers. MB intravascular ultrasound was performed before and after MB stent implantation, and fractional flow reserve was measured in the jailed SB. The vessel volume index of both the proximal and distal MB was increased after stent implantation. The plaque volume index decreased in the proximal MB (9.1±3.0 to 8.4±2.4 mm3/mm, P=0.001), implicating plaque shift, but not in the distal MB (5.4±1.8 to 5.3±1.7 mm3/mm, P=0.227), implicating carina shifting to account for the change in vessel size (N=56). The mean SB fractional flow reserve was 0.71±0.20 (N=68) and 43% of the lesions were functionally significant. Binary logistic-regression analysis revealed that preintervention % diameter stenosis of the SB (odds ratio=1.05; 95% CI, 1.01 to 1.09) and the MB minimum lumen diameter located distal to the SB ostium (odds ratio=3.86; 95% CI, 1.03 to 14.43) were independent predictors of functionally significant SB jailing. In patients with ≥75% stenosis and Thrombolysis In Myocardial Infarction grade 3 flow in the SB, no difference in poststent angiographic and intravascular ultrasound parameters was found between SB lesions with and without functional significance. Conclusions—Both plaque shift from the MB and carina shift contribute to the creation/aggravation of an SB ostial lesion after MB stent implantation. Anatomic evaluation does not reliably predict the functional significance of a jailed SB stenosis. Clinical Trial Registration:http://www.clinicaltrials.gov. Unique Identifier: NCT00553670.

High prevalence of current asthma and active smoking effect among the elderly

Background Although asthma is a common cause of morbidity in adults, relatively few objectively measured population studies of asthma prevalence in adult populations have been conducted.

Noninvasive Diagnosis of Ischemia-Causing Coronary Stenosis Using CT Angiography : Diagnostic Value of Transluminal Attenuation Gradient and Fractional Flow Reserve Computed From Coronary CT Angiography Compared to Invasively Measured Fractional Flow Reserve

OBJECTIVES The aim of this study was to compare the diagnostic performance of coronary computed tomography angiography (CCTA)-derived computed fractional flow reserve (FFR(CT)) and transluminal attenuation gradient (TAG) for the diagnosis of lesion-specific ischemia. BACKGROUND Although CCTA is commonly used to detect coronary artery disease (CAD), it cannot reliably assess the functional significance of CAD. Novel technologies based on CCTA were developed to integrate anatomical and functional assessment of CAD; however, the diagnostic performance of these methods has never been compared. METHODS Fifty-three consecutive patients who underwent CCTA and coronary angiography with FFR measurement were included. Independent core laboratories determined CAD severity by CCTA, TAG, and FFR(CT). The TAG was defined as the linear regression coefficient between intraluminal radiological attenuation and length from the ostium; FFR(CT) was computed from CCTA data using computational fluid dynamics technology. RESULTS Among 82 vessels, 32 lesions (39%) had ischemia by invasive FFR (FFR ≤0.80). Sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratio of TAG (≤ -0.654 HU/mm) for detection of ischemia were 38%, 88%, 67%, 69%, 3.13, and 0.71, respectively; and those of FFR(CT) were 81%, 94%, 90%, 89%, 13.54, and 0.20, respectively. Receiver-operating characteristic curve analysis showed a significantly larger area under the curve (AUC) for FFR(CT) (0.94) compared to that for TAG (0.63, p < 0.001) and CCTA stenosis (0.73, p < 0.001). In vessels with noncalcified plaque or partially calcified plaque, FFR(CT) showed a larger AUC (0.94) compared to that of TAG (0.63, p < 0.001) or CCTA stenosis (0.70, p < 0.001). In vessels with calcified plaque, AUC of FFR(CT) (0.92) was not statistically larger than that of TAG (0.75, p = 0.168) or CCTA stenosis (0.80, p = 0.195). CONCLUSIONS Noninvasive FFR computed from CCTA provides better diagnostic performance for the diagnosis of lesion-specific ischemia compared to CCTA stenosis and TAG.

Prognostic Value of Neutrophil to Lymphocyte Ratio in Patients Presenting With ST-Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

Atherosclerosis is an inflammatory process, and inflammatory biomarkers have been identified as useful predictors of clinical outcomes. The prognostic value of leukocyte count in patients with ST-segment elevation myocardial infarctions who undergo primary percutaneous coronary intervention is not clearly defined. In 325 patients with STEMIs treated with primary percutaneous coronary intervention, total and differential leukocyte counts, once at admission and 24 hours thereafter, were measured. The neutrophil/lymphocyte ratio (NLR) was calculated as the ratio of neutrophil count to lymphocyte count. The primary end point was all-cause death. Twenty-five patients (7.7%) died during follow-up (median 1,092 days, interquartile range 632 to 1,464). The total leukocyte count decreased (from 11,853 ± 3,946/μl to 11,245 ± 3,979/μl, p = 0.004) from baseline to 24 hours after admission. Patients who died had higher neutrophil counts (9,887 ± 5,417/μl vs 8,399 ± 3,639/μl, p = 0.061), lower lymphocyte counts (1,566 ± 786/μl vs 1,899 ± 770/μl, p = 0.039), and higher NLRs (8.58 ± 7.41 vs 5.51 ± 4.20, p = 0.001) at 24 hours after admission. Baseline leukocyte profile was not associated with outcomes. The best cut-off value of 24-hour NLR to predict mortality was 5.44 (area under the curve 0.72, 95% confidence interval [CI] 0.52 to 0.82). In multivariate analysis, a 24-hour NLR ≥5.44 was an independent predictor of mortality (hazard ratio 3.12, 95% CI 1.14 to 8.55), along with chronic kidney disease (hazard ratio 4.23, 95% CI 1.62 to 11.1) and the left ventricular ejection fraction (hazard ratio 0.94 for a 3% increase, 95% CI 0.76 to 0.93). In conclusion, NLR at 24 hours after admission can be used for risk stratification in patients with STEMIs who undergo primary PCI. Patients with STEMIs with 24-hour NLRs ≥5.44 are at increased risk for mortality and should receive more intensive treatment.

N-acetylcysteine versus AScorbic acid for preventing contrast-induced nephropathy in patients with renal insufficiency undergoing coronary angiography: NASPI study - a prospective randomized controlled trial.

BACKGROUND Contrast-induced nephropathy (CIN) is a leading cause of hospital-acquired renal failure and affects mortality and morbidity. There has been no study comparing the efficacy of N-acetylcysteine (NAC) and ascorbic acid that have potential for CIN prevention in patients with renal insufficiency. METHODS We conducted a prospective randomized controlled trial. A total of 212 patients who had pre-existing renal impairment with basal creatinine clearance < or =60 mL/min and/or serum creatinine (SCr) level of > or =1.1 mg/dL, were randomized to have either high-dose NAC (1,200 mg orally twice a day before and on the day of coronary catheterization, n = 106) or ascorbic acid (3 g and 2 g orally before, and 2 g twice after coronary catheterization with a 12-hour interval, n = 106). The primary end point was the maximum increase of SCr level, and the secondary end point was the incidence of CIN. RESULTS The maximum increase of SCr level was significantly lower in NAC group than in ascorbic acid group as follows: -0.03 +/- 0.18 mg/dL versus 0.04 +/- 0.20 mg/mL, respectively (P = .026). Patients with diabetes or who had received a high dose of contrast media experienced significantly less rise of SCr level with NAC than ascorbic acid; in diabetic subgroup, -0.05 +/- 0.22 mg/dL versus 0.09 +/- 0.29 mg/mL, respectively (P = .020); in patients with high dose of dye, -0.03 +/- 0.17 mg/dL versus 0.04 +/- 0.21 mg/mL, respectively (P = .032). The incidence of CIN, the secondary end point, tended to be in favor of NAC rather than ascorbic acid, 1.2% versus 4.4%, respectively (P = .370). Notably, among the diabetes patients, the NAC significantly lowered CIN rate than ascorbic acid, 0% (0/38) versus 12.5% (4/32), respectively (P = .039). CONCLUSION High-dose NAC seems more beneficial than ascorbic acid in preventing contrast-induced renal function deterioration in patients, especially diabetic patients, with renal insufficiency undergoing coronary angiography.

Usefulness of 64-slice multidetector computed tomography as an initial diagnostic approach in patients with acute chest pain.

BACKGROUND Recently, multidetector computed tomography (MDCT) has been proposed as an accurate diagnostic tool to evaluate for coronary artery disease. However, the role of MDCT as part of the initial diagnostic for evaluating acute chest pain is less well established. METHODS We prospectively enrolled patients presenting with acute chest pain to the emergency department (ED) and risk stratified them based on the pretest probability for an acute coronary syndrome (ACS): (1) very low, (2) low, (3) intermediate, (4) high, and (5) very high or definite. After exclusion of very low and very high risk patients, 268 patients were randomized to either immediate 64-slice cardiac MDCT or a conventional diagnostic strategy. Number of admissions, ED and hospital length of stay (LOS), and major adverse cardiac events over 30 days of follow-up were compared between the strategies based on the pretest probability for ACS. RESULTS The number of patients ultimately diagnosed with an ACS did not differ between the 2 strategies. Emergency department LOS and total admissions were not different between strategies. Patients in the MDCT-based strategy had a decreased hospital LOS (P = .049) and fewer admissions deemed unnecessary (P = .007). Reductions in unnecessary admissions were more prominent in intermediate-risk patients (P = .015). None of the patients discharged from the ED in the MDCT-based strategy experienced major adverse cardiac events at follow-up. CONCLUSION Use of an MDCT-based strategy in the ED as part of the initial diagnostic approach for patients presenting with acute chest pain is safe and efficiently reduces avoidable admissions in patients with an intermediate pretest probability for ACS.

Clinical and Physiological Outcomes of Fractional Flow Reserve-Guided Percutaneous Coronary Intervention in Patients With Serial Stenoses Within One Coronary Artery

OBJECTIVES This study was performed to evaluate the physiological and clinical outcomes of fractional flow reserve (FFR)-guided revascularization strategy with drug-eluting stents in serial stenoses within the same coronary artery. BACKGROUND Identifying a functionally significant stenosis is difficult when several stenoses exist within 1 coronary artery. METHODS A total of 131 patients (141 vessels and 298 lesions) with multiple intermediate stenoses within the same coronary artery were assessed by FFR with pullback pressure tracings. In vessels with an FFR <0.8, the stenosis that caused the largest pressure step-up was stented first. Major adverse cardiac events were assessed during follow-up. RESULTS FFR was measured 239 times and there were no procedure-related complications. There was a weak negative correlation between FFR and angiographic percent diameter stenosis (r = -0.282, p < 0.001). In total, 116 stents were implanted and revascularization was deferred in 61.1% (182 of 298) of lesions. When the vessels with an initial FFR <0.8 were divided into 2 groups according to FFR after first stenting (FFR ≥0.8 vs. FFR <0.8), there were no differences in baseline angiographic and physiological parameters between the 2 groups. During the mean follow-up of 501 ± 311 days, there was only 1 target vessel revascularization due to in-stent restenosis. There were no events related to deferred lesions. CONCLUSIONS FFR-guided revascularization strategy using pullback pressure tracing in serial stenoses was safe and effective. This strategy can reduce unnecessary intervention and maximize the benefit of percutaneous coronary intervention with drug-eluting stents in patients with multiple stenoses within 1 coronary artery.

Pathological changes according to the severity of asthma

Background There have been many studies concerning pathological changes in bronchial mucosa from asthmatics; however, few studies has been carried out to evaluate pathological changes according to the severity of asthma.