Byung Chun Jung

The Korean Heart Rhythm Society's 2014 Statement on Antithrombotic Therapy for Patients with Nonvalvular Atrial Fibrillation: Korean Heart Rhythm Society

In patients with nonvalvular atrial fibrillation (AF), the risk of stroke varies considerably according to individual clinical status. The CHA2DS2-VASc score is better than the CHADS2 score for identifying truly lower risk patients with AF. With the advent of novel oral anticoagulants (NOACs), the strategy for antithrombotic therapy has undergone significant changes due to its superior efficacy, safety and convenience compared with warfarin. Furthermore, new aspects of antithrombotic therapy and risk assessment of stroke have been revealed: the efficacy of stroke prevention with aspirin is weak, while the risk of major bleeding is not significantly different from that of oral anticoagulant (OAC) therapy, especially in the elderly. Reflecting these pivotal aspects, previous guidelines have been updated in recent years by overseas societies and associations. The Korean Heart Rhythm Society has summarized the new evidence and updated recommendations for stroke prevention of patients with nonvalvular AF. First of all, antithrombotic therapy must be considered carefully and incorporate the clinical characteristics and circumstances of each individual patient, especially with regards to balancing the benefits of stroke prevention with the risk of bleeding, recommending the CHA2DS2-VASc score rather than the CHADS2 score for assessing the risk of stroke, and employing the HAS-BLED score to validate bleeding risk. In patients with truly low risk (lone AF, CHA2DS2-VASc score of 0), no antithrombotic therapy is recommended, whereas OAC therapy, including warfarin (international normalized ratio 2-3) or NOACs, is recommended for patients with a CHA2DS2-VASc score ≥2 unless contraindicated. In patients with a CHA2DS2-VASc score of 1, OAC therapy should be preferentially considered, but depending on bleeding risk or patient preferences, antiplatelet therapy or no therapy could be permitted.

Relationship Between Left Atrial Size and Stroke in Patients With Sinus Rhythm and Preserved Systolic Function

Background/Aims Increased left atrial (LA) size has been proposed as a predictor of poor cardiovascular outcome in the elderly. In the present study, we evaluated the relationship between LA size and stroke in subjects of all ages who presented with preserved left ventricular systolic function (LVSF) and sinus rhythm (SR), and investigated the relationships between LA size and other echocardiographic parameters of diastolic function. Methods A total of 472 subjects were enrolled in the study (161 men, 311 women) and divided into the stroke group (n=75) and control group (n=397). A conventional echocardiographic study was then performed. Subjects with valvular heart disease, atrial fibrillation, or coronary heart disease were excluded. Results The mean subject age was 65.2±5.1 years in the stroke group and 65.6±5.9 years in the control group. Mitral inflow pattern and E & A velocity showed no significant relationship with stroke (p=NS, p=NS, respectively). Left ventricular mass index and LA dimension were significantly related to stroke (p=0.003, p=0.023, respectively), and hypertension showed a marginal relationship with stroke (p=0.050). Age was not related to stroke in the present study (p=NS). Conclusions The LA dimension is significantly related to the incidence of stroke. Therefore, strategies for prevention of stroke in patients with preserved LVSF and SR should be considered in cases of LA enlargement.

Effect of Valsartan on N-Terminal Pro-Brain Natriuretic Peptide in Patient With Stable Chronic Heart Failure: Comparison With Enalapril

Background and Objectives The plasma concentration of N-terminal pro-brain natriuretic peptide (NT-pro-BNP) is a st-rong prognostic indicator for patients with heart failure (HF) across all stages of the condition. Several clinical trials have de-monstrated convincingly that neurohormonal modulation on the renin angiotensin system (RAS) decreases plasma NT-pro-BNP level and results in favorable outcomes. But there are still limited comparative data on the neuro-hormonal modulatory effects of two RAS inhibitors: angiotensin converting enzyme inhibitor and angiotensin receptor blocker. Subjects and Methods This study was a prospective, multi-center, randomized, open-label, controlled, and non-inferiority study involving 445 patients with left ventricular ejection fraction (LVEF) less than 45%. Patients were assigned to receive either valsartan (target dose of 160 mg bid) or enalapril (target dose of 10 mg bid) for 12 months. We compared plasma NT-pro-BNP, high sensitive C-reactive protein (hs-CRP) level and echocardiographic parameters before and after treatment with valsartan or enalapril. Results: The NT-pro-BNP and hs-CRP levels were significantly decreased after 12 months of treatment with valsartan and enalapril. The percentage change was similar between both groups. LVEF improved and left ventricular internal dimensions were decreased in both groups, and there were no significant differences between two groups. Conclusion Valsartan is as effective on improving plasma NT-pro-BNP level as enalapril in patients with stable chronic HF.

Improvement in Left Ventricular Systolic Dyssynchrony in Hypertensive Patients After Treatment of Hypertension

Background and Objectives Left ventricular (LV) dyssynchrony has been commonly detected among hypertensive patients with normal LV systolic function and no evidence of congestive heart failure. The purpose of our study was to assess the changes in LV systolic dyssynchrony (SDSLV) among hypertensive patients after antihypertensive treatment, and to determine the relationship between SDSLV and other conventional echocardiographic parameters. Subjects and Methods Forty one hypertensive patients with normal LV ejection fraction were enrolled. By performing a conventional echocardiographic study, the SDSLV was measured as the time difference between the shortest and longest time of the peak myocardial systolic velocities among 12 segments of the basal and mid-levels of the 3 apical views, and radial dyssynchrony of the basal (RDSbase) and mid-levels (RDSmid) measured as the time difference between the earliest and latest peak values on the radial strain curves of each level of the parasternal short-axis views. Results Compared to baseline after six months of antihypertensive treatment, the SDSLV improved significantly (48.7±37.9 ms vs. 29.5±34.1 ms, p=0.020). Also the RDSbase and RDSmid improved significantly in respect to the baseline values (129.9±136.3 ms vs. 38.8±45.4 ms, p=0.002 and 75.2±63.8 ms vs. 28.2±37.7 ms, respectively, p<0.001). Conclusion The severity of SDSLV improved with antihypertensive treatment, and was associated with the regression of LV mass. Furthermore, it might precede improvement in the mitral inflow pattern, as assessed by conventional echocardiography, so that early detection of the benefit of antihypertensive treatment may be possible.