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Chang-Wook Nam - Top 30 Publications

Clinical Outcomes of Deferred Lesions With Angiographically Insignificant Stenosis But Low Fractional Flow Reserve.

Data are limited regarding outcomes of deferred lesions in patients with angiographically insignificant stenosis but low fractional flow reserve (FFR). We investigated the natural history of angiographically insignificant stenosis with low FFR among patients who underwent routine 3-vessel FFR measurement.

Evaluation of the impact of statin therapy on the obesity paradox in patients with acute myocardial infarction: A propensity score matching analysis from the Korea Acute Myocardial Infarction Registry.

The phenomenon of obesity paradox after acute myocardial infarction (AMI) has been reported under strong recommendation of statin therapy. However, the impact of statin therapy on this paradox has not been investigated. This study investigated the impact of statin therapy on 1-year mortality according to obesity after AMI. A total of 2745 AMI patients were included from the Korea Acute Myocardial Infarction Registry after 1:4 propensity score matching analysis (n = 549 for nonstatin group and n = 2196 for statin group). Primary and secondary outcomes were all-cause and cardiac death, respectively. During 1-year follow-up, the incidence of all-cause (8.4% vs 3.7%) and cardiac (6.2% vs 2.3%) death was higher in nonstatin group than in statin (P < .001, respectively). In nonstatin group, the incidence of all-cause (7.2% vs 9.0%) and cardiac (5.5% vs 6.5%) death did not differ significantly between obese and nonobese patients. However, in statin group, obese patients had lower 1-year rate of all-cause (1.7% vs 4.8%) and cardiac (1.2% vs 2.9%) death (P < .05, respectively), and lower cumulative rates by Kaplan-Meier analysis of all-cause and cardiac death compared with nonobese patients (log-rank P < .05, respectively). The overall risk of all-cause death was significantly lower in obese than in nonobese patients only in statin group (hazard ratio: 0.35; P = .001). After adjusting for confounding factors, obesity was independently associated with decreased risk of all-cause death in statin group. In conclusion, the greater benefit of statin therapy for survival in obese patients is further confirmation of the obesity paradox after AMI.

Discrepancy between fractional flow reserve and instantaneous wave-free ratio: Clinical and angiographic characteristics.

The invasive physiologic index such as fractional flow reserve (FFR) or instantaneous wave-free ratio (iFR) is used in clinical practice to identify ischemia-causing stenosis and to guide treatment strategy. We investigated clinical and angiographic characteristics of lesions with discrepancy between FFR and iFR.

Efficacy and Tolerability of Combination Therapy Versus Monotherapy with Candesartan and/or Amlodipine for Dose Finding in Essential Hypertension: A Phase II Multicenter, Randomized, Double-blind Clinical Trial.

Intensive blood pressure (BP) lowering is important for the treatment of hypertension; however, it has been a challenge to achieve target BP in many patients. The purpose of this study was to explore the optimal dosage of a fixed-dose combination of candesartan cilexetil (CAN) and amlodipine besylate (AML), by examining the tolerability and efficacy of CAN/AML combination therapy compared with those of monotherapy with either drug in patients with essential hypertension.

Prognosis of Deferred Non-culprit Lesions According to Fractional Flow Reserve in Patients with Acute Coronary Syndrome.

There are limited data on the prognosis of deferred non-culprit lesions in patients with acute coronary syndrome (ACS) based on fractional flow reserve (FFR). We investigated the prognosis of deferred non-culprit lesions in ACS patients, compared with deferred lesions in patients with stable coronary artery disease (SCAD), on the basis of FFR.

Diagnostic Performance of a Novel Method for Fractional Flow Reserve Computed from Noninvasive Computed Tomography Angiography (NOVEL-FLOW Study).

Coronary computed tomography angiography (CCTA)-derived fractional flow reserve from computed tomography (CT-FFR) may provide better diagnostic performance over CCTA alone, but the complexity of its method limits the use in clinical environment. The aim of the present study is to validate a newly developed vessel-length based computational fluid dynamics scheme for the computation of FFR based on CCTA data, compare them with invasively measured FFR, and evaluate its diagnostic performance with that of CCTA. One hundred seventeen patients from 4 medical institutions who had clinically indicated invasive coronary angiography for suspected coronary artery disease (CAD) were enrolled. Invasive FFR measurement was performed in 218 vessels and these measurements were regarded as the reference standard. The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of CT-FFR on a per-vessel basis were 85.8%, 86.2%, 85.5%, 79.8%, and 90.3%, respectively, for CT-FFR ≤0.80, and 66.1%, 75.9%, 59.5%, 55.5%, and 78.8%, respectively, for CCTA ≥50%. A higher area under the receiver operating characteristic curve for CT-FFR was observed compared with CCTA (0.93 vs 0.74, p <0.0001). The CT-FFR and FFR correlated well (r = 0.76, p <0.001) with slight underestimation by CT-FFR (0.014 ± 0.077, p = 0.007). With a novel method of vessel-length based computational fluid dynamics scheme, CT-FFR can be performed at a personal computer enhancing its applicability in clinical situation. The diagnostic accuracy of CT-FFR for the detection of functionally significant CAD was good and was superior to that of CCTA within a population of suspected CAD.

Fractional Flow Reserve and Cardiac Events in Coronary Artery Disease: Data From a Prospective IRIS-FFR Registry (Interventional Cardiology Research Incooperation Society Fractional Flow Reserve).

We evaluated the prognosis of deferred and revascularized coronary stenoses after fractional flow reserve (FFR) measurement to assess its revascularization threshold in clinical practice.

Use of the Instantaneous Wave-free Ratio or Fractional Flow Reserve in PCI.

Coronary revascularization guided by fractional flow reserve (FFR) is associated with better patient outcomes after the procedure than revascularization guided by angiography alone. It is unknown whether the instantaneous wave-free ratio (iFR), an alternative measure that does not require the administration of adenosine, will offer benefits similar to those of FFR.

Identification of Coronary Artery Side Branch Supplying Myocardial Mass That May Benefit From Revascularization.

The authors sought to identify whether a coronary side branch (SB) is supplying a myocardial mass that may benefit from revascularization.

Between-visit reproducibility of inter-arm systolic blood pressure differences in treated hypertensive patients: the coconet study.

Inter-arm systolic blood pressure (BP) differences (sIADs) have recently been recognized as a risk factor for cardiovascular mortality. However, sIAD reproducibility remains unresolved from a controlled trial perspective. We evaluated the between-visit reproducibility of sIADs in hypertensive patients. We examined 1875 hypertensive participants aged 20 years and older (mean age: 62.3 years, 45.4% female) from nine primary clinics and 27 secondary and tertiary hospitals. The BPs in both arms were automatically and simultaneously measured in triplicate with a cuff-oscillometric BP device. BP measurements were obtained at baseline and at 3-month follow-up time points. Increased sIAD was defined as an absolute difference of ⩾10 mm Hg in the average systolic BPs between the left and right arms. The overall mean sIAD was 4.33±4.17 mm Hg. The prevalences of increased sIAD at baseline and at the 3-month measurements were 7.6% and 7.1%, respectively. The intraclass correlation coefficient for the between-visit sIADs was 0.304 (95% confidence interval (CI) 0.262-0.344). The κ-value between the baseline and follow-up increased sIADs was 0.165 (95% CI 0.096-0.234). The percentage of patients who exhibited an increased sIAD at 3 months compared with the initially increased sIAD at baseline was 21.8%. The reproducibility of sIAD determination between baseline and the 3-month follow-up measurements lacked agreement in the hypertensive patients. Further studies should identify the relevant variables and characteristics of this poor reproducibility (CRIS number; KCT0001235).

Clinical Outcomes in Patients with Deferred Coronary Lesions according to Disease Severity Assessed by Fractional Flow Reserve.

Data on the clinical outcomes in deferred coronary lesions according to functional severity have been limited. This study evaluated the clinical outcomes of deferred lesions according to fractional flow reserve (FFR) grade using Korean FFR registry data. Among 1,294 patients and 1,628 lesions in Korean FFR registry, 665 patients with 781 deferred lesions were included in this study. All participants were consecutively categorized into 4 groups according to FFR; group 1: ≥ 0.96 (n = 56), group 2: 0.86-0.95 (n = 330), group 3: 0.81-0.85 (n = 170), and group 4: ≤ 0.80 (n = 99). Primary endpoint was major adverse cardiac events (MACE), a composite of all-cause death, myocardial infarction, and target vessel revascularization. The median follow-up period was 2.1 years. During follow-up, the incidence of MACE in groups 1-4 was 1.8%, 7.6%, 8.8%, and 13.1%, respectively. Compared to group 1, the cumulative rate by Kaplan-Meier analysis of MACE was not different for groups 2 and 3. However, group 4 had higher cumulative rate of MACE compared to group 1 (log-rank P = 0.013). In the multivariate Cox hazard models, only FFR (hazard ratio [HR], 0.95; P = 0.005) was independently associated with MACE among all participants. In contrast, previous history of percutaneous coronary intervention (HR, 2.37; P = 0.023) and diagnosis of acute coronary syndrome (ACS) (HR, 2.35; P = 0.015), but not FFR, were independent predictors for MACE in subjects with non-ischemic (FFR ≥ 0.81) deferred coronary lesions. Compared to subjects with ischemic deferred lesions, clinical outcomes in subjects with non-ischemic deferred lesions according to functional severity are favorable. However, longer-term follow-up may be necessary.

Impact of Longitudinal Lesion Geometry on Location of Plaque Rupture and Clinical Presentations.

This study sought to investigate the impact of longitudinal lesion geometry on the location of plaque rupture and clinical presentation and its mechanism.

Efficacy and safety of fixed-dose combination therapy with olmesartan medoxomil and rosuvastatin in Korean patients with mild to moderate hypertension and dyslipidemia: an 8-week, multicenter, randomized, double-blind, factorial-design study (OLSTA-D RCT: OLmesartan rosuvaSTAtin from Daewoong).

The pill burden of patients with hypertension and dyslipidemia can result in poor medication compliance. This study aimed to evaluate the efficacy and safety of fixed-dose combination (FDC) therapy with olmesartan medoxomil (40 mg) and rosuvastatin (20 mg) in Korean patients with mild to moderate hypertension and dyslipidemia. This multicenter, randomized, double-blind, factorial-design study included patients aged ≥20 years with mild to moderate essential hypertension and dyslipidemia. Patients were randomly assigned to receive FDC therapy (40 mg olmesartan medoxomil, 20 mg rosuvastatin), 40 mg olmesartan medoxomil, 20 mg rosuvastatin, or a placebo. The percentage change from baseline in low-density lipoprotein cholesterol levels was compared between FDC therapy and olmesartan medoxomil, and the change from baseline in diastolic blood pressure was compared between FDC therapy and rosuvastatin 8 weeks after treatment. A total of 162 patients were included. The least square mean percentage change (standard error) from baseline in low-density lipoprotein cholesterol levels 8 weeks after treatment was significantly greater in the FDC than in the olmesartan medoxomil group (-52.3% [2.8%] vs -0.6% [3.5%], P<0.0001), and the difference was -51.7% (4.1%) (95% confidence interval: -59.8% to -43.6%). The least square mean change (standard error) from baseline in diastolic blood pressure 8 weeks after treatment was significantly greater in the FDC group than in the rosuvastatin group (-10.4 [1.2] mmHg vs 0.1 [1.6] mmHg, P<0.0001), and the difference was -10.5 (1.8) mmHg (95% confidence interval: -14.1 to -6.9 mmHg). There were 50 adverse events in 41 patients (22.7%) and eight adverse drug reactions in five patients (2.8%). The study found that FDC therapy with olmesartan medoxomil and rosuvastatin is an effective, safe treatment for patients with hypertension and dyslipidemia. This combination may improve medication compliance in patients with a large pill burden.

Effect of fixed-dose combinations of ezetimibe plus rosuvastatin in patients with primary hypercholesterolemia: MRS-ROZE (Multicenter Randomized Study of ROsuvastatin and eZEtimibe).

We aimed to compare the effects of fixed-dose combinations of ezetimibe plus rosuvastatin to rosuvastatin alone in patients with primary hypercholesterolemia, including a subgroup analysis of patients with diabetes mellitus (DM) or metabolic syndrome (MetS).

A Randomized, Double-blind, Multicenter, Phase III Study to Evaluate the Efficacy and Safety of Fimasartan/Amlodipine Combined Therapy Versus Fimasartan Monotherapy in Patients With Essential Hypertension Unresponsive to Fimasartan Monotherapy.

The goal of this study was to evaluate whether the blood pressure-lowering efficacy of fimasartan/amlodipine combination therapy was superior to that of fimasartan monotherapy after 8 weeks of treatment in patients with hypertension who had failed to respond adequately to fimasartan monotherapy.

Does Pre-Treatment with High Dose Atorvastatin Prevent Microvascular Dysfunction after Percutaneous Coronary Intervention in Patients with Acute Coronary Syndrome?

There is controversy surrounding whether or not high dose statin administration before percutaneous coronary intervention (PCI) decreases peri-procedural microvascular injury. We performed a prospective randomized study to investigate the mechanisms and effects of pre-treatment high dose atorvastatin on myocardial damage in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS) undergoing PCI.

Discrepancy between frequency domain optical coherence tomography and intravascular ultrasound in human coronary arteries and in a phantom in vitro coronary model.

This purpose of this study is to evaluate, concomitantly with quantitative coronary angiography (QCA), the potential discrepancy between frequency domain optical coherence tomography (FD-OCT) and intravascular ultrasound (IVUS) measurements in a phantom coronary model and in human coronary arteries within and outside stented segments.

Physiological Severity of Coronary Artery Stenosis Depends on the Amount of Myocardial Mass Subtended by the Coronary Artery.

This study investigated the role of fractional myocardial mass (FMM), a vessel-specific myocardial mass, in the evaluation of physiological severity of stenosis. Using computed tomography angiography, the study investigated fractional myocardial mass, a concept of myocardial mass subtended by specific vessel, which could reduce anatomical-physiological mismatch.

Prognosis of Variant Angina Manifesting as Aborted Sudden Cardiac Death.

The long-term prognosis of patients with variant angina presenting with aborted sudden cardiac death (ASCD) is unknown.

Angiographically minimal but functionally significant coronary lesion confirmed by optical coherence tomography.

Computational fluid dynamic measures of wall shear stress are related to coronary lesion characteristics.

To assess the distribution of pressure and shear-related forces acting on atherosclerotic plaques and their association with lesion characteristics using coronary CT angiography (cCTA)-based computational fluid dynamics (CFD) model of epicardial coronary arteries.

Safety and efficacy of intracoronary nicorandil as hyperaemic agent for invasive physiological assessment: a patient-level pooled analysis.

Our aim was to evaluate the safety and efficacy of intracoronary (IC) nicorandil as an alternative choice of hyperaemic agent for invasive physiologic studies.

Initial Total Bilirubin and Clinical Outcome in Patients With ST-Segment Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention With Drug-Eluting Stents.

Total bilirubin (TB) concentration is inversely associated with stable coronary artery disease, but there have been few studies on initial TB in patients with ST-segment elevation myocardial infarction (STEMI).

The Prognostic Value of Residual Coronary Stenoses After Functionally Complete Revascularization.

The residual SYNTAX score (RSS) and SYNTAX revascularization index (SRI) quantitatively assess angiographic completeness of revascularization for patients with multivessel coronary artery disease. Whether residual angiographic disease remains of prognostic importance after "functionally" complete revascularization with fractional flow reserve (FFR) guidance is unknown.

Two-Year Safety and Efficacy of Biodegradable Polymer Drug-Eluting Stent Versus Second-Generation Durable Polymer Drug-Eluting Stent in Patients With Acute Myocardial Infarction: Data from the Korea Acute Myocardial Infarction Registry (KAMIR).

Despite improved long-term safety of biodegradable polymer (BP) drug-eluting stents (DES) compared to first-generation durable polymer (DP) DES, data on the safety and efficacy of BP-DES compared with second-generation (2G) DP-DES in patients with acute myocardial infarction (AMI) are limited.

Significance of apical cavity obliteration in apical hypertrophic cardiomyopathy.

Apical hypertrophic cardiomyopathy (HCM) is characterised by apical systolic obliteration and is associated with atrial fibrillation (AF), stroke, heart failure (HF), and mortality. We investigated whether apical obliteration of the left ventricular (LV) cavity could have an unfavourable impact on the clinical course of apical HCM.

Coronary Flow Reserve and Microcirculatory Resistance in Patients With Intermediate Coronary Stenosis.

The prognostic impact of microvascular status in patients with high fractional flow reserve (FFR) is not clear.

Usefulness of Frequency Domain Optical Coherence Tomography Compared with Intravascular Ultrasound as a Guidance for Percutaneous Coronary Intervention.

To compare outcomes and rates of optimal stent placement between optical coherence tomography (OCT) and intravascular ultrasound (IVUS) guided percutaneous coronary intervention (PCI).

Long-Term Clinical Outcomes of Fractional Flow Reserve-Guided Versus Routine Drug-Eluting Stent Implantation in Patients With Intermediate Coronary Stenosis: Five-Year Clinical Outcomes of DEFER-DES Trial.

We aimed to compare the long-term clinical outcomes between fractional flow reserve (FFR)-guided and routine drug-eluting stent (DES) implantation in patients with an intermediate coronary stenosis.

Integrated physiologic assessment of ischemic heart disease in real-world practice using index of microcirculatory resistance and fractional flow reserve: insights from the International Index of Microcirculatory Resistance Registry.

The index of microcirculatory resistance (IMR) is a quantitative and specific index for coronary microcirculation. However, the distribution and determinants of IMR have not been fully investigated in patients with ischemic heart disease (IHD).