Hyungseop Kim

Outcomes of percutaneous coronary intervention in intermediate coronary artery disease: fractional flow reserve-guided versus intravascular ultrasound-guided.

OBJECTIVES This study sought to evaluate the long-term clinical outcomes of a fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) strategy compared with intravascular ultrasound (IVUS)-guided PCI for intermediate coronary lesions. BACKGROUND Both FFR- and IVUS-guided PCI strategies have been reported to be safe and effective in intermediate coronary lesions. METHODS The study included 167 consecutive patients, with intermediate coronary lesions evaluated by FFR or IVUS (FFR-guided, 83 lesions vs. IVUS-guided, 94 lesions). Cutoff value of FFR in FFR-guided PCI was 0.80, whereas that for minimal lumen cross sectional area in IVUS-guided PCI was 4.0 mm(2). The primary outcome was defined as a composite of major adverse cardiac events including death, myocardial infarction, and ischemia-driven target vessel revascularization at 1 year after the index procedure. RESULTS Baseline percent diameter stenosis and lesion length were similar in both groups (51 +/- 8% and 24 +/- 12 mm in the FFR group vs. 52 +/- 8% and 24 +/- 13 mm in the IVUS group, respectively). However, the IVUS-guided group underwent revascularization therapy significantly more often (91.5% vs. 33.7%, p < 0.001). No significant difference was found in major adverse cardiac event rates between the 2 groups (3.6% in FFR-guided PCI vs. 3.2% in IVUS-guided PCI). Independent predictors for performing intervention were guiding device: FFR versus IVUS (relative risk [RR]: 0.02); left anterior descending coronary artery versus non-left anterior descending coronary artery disease (RR: 5.60); and multi- versus single-vessel disease (RR: 3.28). CONCLUSIONS Both FFR- and IVUS-guided PCI strategy for intermediate coronary artery disease were associated with favorable outcomes. The FFR-guided PCI reduces the need for revascularization of many of these lesions.

Decision-making model for early diagnosis of congestive heart failure using rough set and decision tree approaches

The accurate diagnosis of heart failure in emergency room patients is quite important, but can also be quite difficult due to our insufficient understanding of the characteristics of heart failure. The purpose of this study is to design a decision-making model that provides critical factors and knowledge associated with congestive heart failure (CHF) using an approach that makes use of rough sets (RSs) and decision trees. Among 72 laboratory findings, it was determined that two subsets (RBC, EOS, Protein, O2SAT, Pro BNP) in an RS-based model, and one subset (Gender, MCHC, Direct bilirubin, and Pro BNP) in a logistic regression (LR)-based model were indispensable factors for differentiating CHF patients from those with dyspnea, and the risk factor Pro BNP was particularly so. To demonstrate the usefulness of the proposed model, we compared the discriminatory power of decision-making models that utilize RS- and LR-based decision models by conducting 10-fold cross-validation. The experimental results showed that the RS-based decision-making model (accuracy: 97.5%, sensitivity: 97.2%, specificity: 97.7%, positive predictive value: 97.2%, negative predictive value: 97.7%, and area under ROC curve: 97.5%) consistently outperformed the LR-based decision-making model (accuracy: 88.7%, sensitivity: 90.1%, specificity: 87.5%, positive predictive value: 85.3%, negative predictive value: 91.7%, and area under ROC curve: 88.8%). In addition, a pairwise comparison of the ROC curves of the two models showed a statistically significant difference (p<0.01; 95% CI: 2.63-14.6).

Fractional Flow Reserve Versus Angiography in Left Circumflex Ostial Intervention After Left Main Crossover Stenting

Background and Objectives Discrepancy between angiographic percent (%) diameter stenosis and fractional flow reserve (FFR) exists in non-left main bifurcation lesions. The aim of this study was to compare angiographic stenosis severity and FFR in jailed ostial left circumflex artery (LCX) lesions after left main (LM)-to-left anterior descending artery (LAD) crossover stenting. Subjects and Methods Twenty-nine (n=29) patients with distal LM or ostial LAD lesions treated by LM-to-LAD crossover stenting were consecutively enrolled. After successful stenting, FFR was measured at the jailed LCX. Additional intervention was performed in lesions with FFR <0.8. Results The mean reference diameter of LCX was 3.1±0.4 mm, and percent diameter stenosis after crossover stenting was 56±21%. Angiographically significant stenosis (>50%) at the ostial LCX occurred in 59% (17/29) of cases. Among them, only five (29%) lesions had functional significance, and underwent additional procedure. During follow-up, three patients in the deferral group and two patients in the additional intervention group had target lesion revascularization. Conclusion There was a discrepancy between angiographic percent diameter stenosis and FFR in jailed LCX lesions after LM crossover stenting.

Relation of fractional flow reserve after drug-eluting stent implantation to one-year outcomes.

Patients still present with drug-eluting stent (DES) failure despite an angiographically successful implantation. The aim of the present study was to investigate the relation between the fractional flow reserve (FFR) measured after DES implantation and the clinical outcomes at 1 year. A total of 80 patients (mean age 62 years, 74% men, 99 DESs) underwent coronary pressure measurement at maximum hyperemia after successful DES implantation. The composite of major adverse cardiac events (MACE), including death, myocardial infarction, and ischemia-driven target vessel revascularization was evaluated at 1 year. The patients were divided into 2 groups (low-FFR group, FFR ≤0.90 and high-FFR group, FFR >0.90) according to the median FFR. The mean poststent percent diameter stenosis was 11 ± 5% in the low-FFR group and 12 ± 3% in the high-FFR group (p = 0.31). Left anterior descending coronary artery lesions were more frequent in the low-FFR group than in the high-FFR group (82% vs 55%, p = 0.02). The mean stent length was greater in the low-FFR group than in the high-FFR group (38 ± 18 vs 28 ± 13 mm, p = 0.01). Six cases (7.5%) of MACE occurred during the 1-year follow-up. The rate of MACE was 12.5% in the low-FFR group and 2.5% in the high-FFR group (p <0.01). Receiver operating characteristic curves revealed 0.90 as the best cutoff of FFR after DES implantation for the prediction of 1-year MACE. In conclusion, a poststent FFR of ≤0.90 correlated with a greater adverse event rate at 1 year.

Incidence and predictors of silent embolic cerebral infarction following diagnostic coronary angiography

BACKGROUND Coronary angiography (CAG) is an invasive diagnostic procedure, which could lead to procedure related complications. One of the well known post-procedural complications is cerebral embolic infarction with or without symptoms. Silent embolic cerebral infarction (SECI) has clinical significance because it can progress to a decline in cognitive function and increase the risk of dementia in the long term. The aim of this study was to detect the incidence and predictors of SECI after diagnostic CAG using diffusion-weighted magnetic resonance imaging (DW-MRI). METHODS A total of 197 patients with coronary artery disease who underwent DW-MRI for evaluation of intracranial vasculopathy before coronary artery bypass graft surgery were retrospectively enrolled in the present study. DW-MRI was performed within 48 h after diagnostic CAG. SECI was diagnosed as presence of focal bright high signal intensity in DW-MRI. Patients were divided into groups according to presence/absence of SECI (+ SECI vs. - SECI, respectively). The clinical and angiographic characteristics were analyzed and independent predictors were evaluated. RESULTS Of the 197 patients, SECI occurred in 20 patients (10.2%) after diagnostic CAG. Age, female gender, frequency of underlying atrial fibrillation, extent of coronary disease, and fluoroscopic time during diagnostic CAG were not different between the + SECI and - SECI groups. Left ventricular ejection fraction was significantly lower in the + SECI group than in the - SECI group (45.9 ± 8.5% vs. 51.4 ± 13.1%, p=0.014) and performance rate of internal mammary artery (IMA) angiography was significantly higher in the + SECI group compared with the - SECI group (85% vs. 37.2%, p<0.001). By multivariate analysis, performing IMA angiography was the only predictor of SECI (OR=14.642; 95% CI=3.201 to 66.980, p=0.001). CONCLUSIONS The incidence of SECI after diagnostic CAG was not infrequent. Diagnostic CAG with IMA angiography may increase the risk of SECI.

The Correlation of Left Atrial Volume Index to the Level of N‐Terminal Pro‐BNP in Heart Failure with a Preserved Ejection Fraction

Background: Patients with heart failure with a preserved ejection fraction (HFPEF) have high N‐terminal pro‐B‐type natriuretic peptide (NT‐pro‐BNP) level and a high ratio of early transmitral inflow to diastolic velocity of the mitral annulus (E/E′) derived from tissue Doppler imaging (TDI). Because left atrial volume indexed to body surface area (LAVI) is believed to reflect chronic diastolic dysfunction, we assessed the ability of LAVI and E/E′ ratio to predict NT‐pro‐BNP level in patients with HFPEF. Methods: One hundred forty‐eight patients with HFPEF (ejection fraction ≥ 50%, NT‐pro‐BNP ≥ 100 pg/ml) underwent conventional echocardiography including LAVI and E/E′ ratio, which were compared with NT‐pro‐BNP level. Results: In the overall patient population, modest correlations were found between NT‐pro‐BNP level and peak systolic TDI (S′) (P = 0.009), LAVI (P = 0.009), and E/E′ ratio (P = 0.017). However, in patients with E/E′ ratio ≥13, LAVI was the most important predictor of NT‐pro‐BNP level (P < 0.001), whereas in those with E/E′ ratio <13 it was S′ (P < 0.001) in multivariate analysis. Conclusion: In patients with HFPEF evidenced by high NT‐pro‐BNP level, LAVI correlates with NT‐pro‐BNP level in the setting of elevated E/E′ ratio. However, in the setting of low E/E′ ratio, LAVI does not seem to be associated with NT‐pro‐BNP level.

Relationship between early diastolic strain rate imaging and left ventricular geometric patterns in hypertensive patients.

Hypertension is an important contributor to different left ventricular (LV) geometric patterns with resultant myocardial dysfunction. Strain rate image (SRI) has been suggested as a useful tool for the evaluation of myocardial function. The aim of this study was to assess whether SRI correlates with LV geometric patterns in hypertensive subjects. Fifty-one hypertensive subjects and 21 healthy controls were enrolled and examined with conventional echocardiography including LV mass index (LVMI). Moreover, tissue Doppler imaging (TDI) and strain or SRI were obtained in all subjects. The hypertensives were subanalyzed according to geometric patterns. The hypertensive subjects were more likely to have enlarged left atrial dimensions, prolonged decelerating time and isovolumic relaxation time, and showed a lower TDI of early diastolic mitral annulus and SRI of early diastolic component (SR-e). Among hypertensive subjects, there was a significant trend toward a lower value of SR-e in those with hypertrophy and SR-e was the lowest in the concentric hypertrophy than other geometric patterns. In addition, SR-e was associated most strongly with LVMI of LV other than echoparameters. The hypertrophic hypertensive subjects showed altered systolic and/or diastolic function. Moreover, SR-e appeared to be correlated most with geometric patterns according to LVMI.

Trends in Oral Anticoagulation Therapy Among Korean Patients With Atrial Fibrillation: The KORean Atrial Fibrillation Investigation

Background and Objectives Anticoagulation with vitamin K antagonists (VKAs) such as warfarin provides effective stroke prophylaxis in patients with atrial fibrillation (AF). We conducted a large multicenter survey of Korean patients with AF to determine trends in VKA use. Subjects and Methods Eligible patients were adults with AF that had been prescribed VKAs. Medical records from a total of 5616 patients {mean age 63.6±12.2 years, male 3150 (56.1%)} in 27 hospitals from Jan. 2001 to Oct. 2007 were reviewed. Results The mean international normalized ratio (INR) was 2.04±0.64, and mean dosage of VKA was 3.66±1.50 mg. Individuals in their sixties (1852 patients) accounted for about one third of patients studied. As patients grew older, INR increased and VKA dosage decreased. The dosage of VKA in male patients was larger than that in females for all ages. A total of 2146 (42.4%) patients had an INR of 2-3, and less than 40% patients in their sixties had an INR within optimal range. The dosage of oral anticoagulant for optimal INR level was 3.71 mg. Conclusion In this study, less than half of the Korean patients with AF on VKA reached the therapeutic range of INR. Mean dosage of VKA was 3.66±1.50 mg, and the dosage of oral anticoagulant for optimal INR level was 3.71 mg, which decreased with age.

Usefulness of tissue Doppler imaging-myocardial performance index in the evaluation of diastolic dysfunction and heart failure with preserved ejection fraction.

In heart failure with preserved ejection fraction (HFPEF), physiological abnormalities are not solely restricted to diastolic function. Because the tissue Doppler imaging (TDI)‐derived myocardial performance index (MPI) offers the advantage of recording systolic and diastolic tissue velocity simultaneously in the same cardiac cycle, this study aimed to determine whether TDI‐MPI is an informative index for assessing HFPEF, compared with conventional echo parameters.

Combination of Uric Acid and NT-ProBNP: A More Useful Prognostic Marker for Short-Term Clinical Outcomes in Patients with Acute Heart Failure

Background/Aims In patients with heart failure (HF), N-terminal prohormone brain natriuretic peptide (NT-ProBNP) is a standard prognostic indicator. In addition, uric acid (UA) was recently established as a prognostic marker for poor outcome in chronic HF. The aim of this study was to determine the combined role of UA and NT-ProBNP as prognostic markers for short-term outcomes of acute heart failure (AHF). Methods The levels of UA and NT-ProBNP were determined in 193 patients (age, 69 ± 13 years; 76 males) admitted with AHF. Patients were followed for 3 months and evaluated for cardiovascular events, defined as cardiac death and/or readmission for HF. Results Of the 193 patients, 23 (11.9%) died and 20 (10.4%) were readmitted for HF during the 3-month follow-up period. Based on univariate analysis, possible predictors of short-term cardiovascular events were high levels of UA and NT-ProBNP, low creatinine clearance, no angiotensin converting enzyme inhibitors or angiotensin receptor blockers, and old age. Multivariate Cox hazard analysis showed that UA levels were independently associated with increased incidence of cardiovascular events (hazard ratio, 1.115; 95% confidence interval, 1.006 to 1.235; p = 0.037). Kaplan-Meier survival analysis revealed that patients with UA levels > 8.0 mg/dL and NT-ProBNP levels > 4,210 pg/mL were at highest risk for cardiac events (p = 0.01). Conclusions The combination of UA and NT-ProBNP levels appears to be more useful than either marker alone as an independent predictor for short-term outcomes in patients with AHF.