The insertion of implantable cardioverter-defibrillators (ICD) in patients with non-ischemic cardiomyopathy (NICM) has been recommended by recent guidelines. However, current evidence shows limited benefits to inserting ICDs in patients with NICM. Recently, the defibrillator implantation in patients with non-ischemic systolic heart failure (DANISH) trial, a large randomized trial of more than 1,100 patients with NICM, was conducted to compare the primary prevention of all-cause mortality between optimal medical therapy, cardiac resynchronization therapy, and ICD implantation. The DANISH trial revealed no differences in all-cause mortality between the groups after 5 years. However, in patients younger than 68 years of age, the rate of death from any cause was significantly lower in the ICD group compared to the control group. In addition, the rate of sudden cardiac death was lower in the ICD group compared to the control group in patients under 68 years. The results of DANISH will likely change guidelines about the insertion of ICD in patients with NICM, and encourage the use of ICD in patients with NICM.
Cardiac Resynchronization Therapy ; Cardiomyopathies* ; Death, Sudden, Cardiac* ; Defibrillators ; Defibrillators, Implantable* ; Heart Failure, Systolic ; Humans ; Mortality ; Primary Prevention*

Cardiac resynchronization therapy (CRT) has been shown to reduce the risk of death and hospitalization in patients with advanced heart failure with left ventricular dysfunction. However, controversy remains regarding who would most benefit from CRT. We performed a meta-analysis, and meta-regression in an attempt to identify factors that determine the outcome after CRT. A total of 23 trials comprising 10,103 patients were selected for this meta-analysis. Our analysis revealed that CRT significantly reduced the risk of all-cause mortality and hospitalization for heart failure compared to control treatment. The odds ratio (OR) of all-cause death had a linear relationship with mean QRS duration (P=0.009). The benefit in survival was confined to patients with a QRS duration > or =145 ms (OR, 0.86; 95% CI, 0.74-0.99), while no benefit was shown among patients with a QRS duration of 130 ms (OR, 1.00; 95% CI, 0.80-1.25) or less. Hospitalization for heart failure was shown to be significantly reduced in patients with a QRS duration > or =127 ms (OR, 0.77; 95% CI, 0.60-0.98). This meta-regression analysis implies that patients with a QRS duration > or =150 ms would most benefit from CRT, and in those with a QRS duration <130 ms CRT implantation may be potentially harmful.
Bundle-Branch Block/physiopathology ; Cardiac Resynchronization Therapy/*methods ; Cardiac Resynchronization Therapy Devices ; Defibrillators, Implantable ; Electrocardiography ; Heart Failure/mortality/physiopathology/*therapy ; Humans ; Myocardial Contraction/*physiology ; Treatment Outcome ; Ventricular Dysfunction, Left/mortality/physiopathology/*therapy

PURPOSE: This study aimed to elucidate which echocardiographic criteria at three time points, for cardiac resynchronization therapy (CRT) response, are accurate in discriminating the hierarchical clinical composite end point (HCCEP). MATERIALS AND METHODS: We included 120 patients (age, 66.1±12.6 years; men, 54.2%) who underwent CRT implantation for heart failure (HF). Echocardiography was performed before and at 3, 6, and 12 months after CRT implantation. The 1-year HCCEP included all-cause mortality, hospitalization for HF, and New York Heart Association functional class for 12 months. CRT response criteria were decrease in left ventricular (LV) end-systolic volume (LVESV) >15%, decrease in LV end-diastolic volume >15%, absolute increase in LV ejection fraction (LVEF) ≥5%, relative increase in LVEF ≥15%, and decrease in mitral regurgitation ≥1 grade. Temporal changes in CRT response rates, accuracy of CRT response criteria at each time and cutoff value for the discrimination of improvement in HCCEP, and agreements with improvement in HCCEP were analyzed. RESULTS: HCCEP improvement rates were 65.8% in total group. In nonischemic group, CRT response rates according to all echocardiographic criteria significantly increased with time. In ischemic group, CRT response rate did not significantly change with time. In total group, ΔLVESV at 6 months (ΔLVESV6) had the most significant accuracy for the discrimination of HCCEP (area under the curve=0.781). The optimal cutoff value of ΔLVESV6 was 13.5% (sensitivity=0.719, specificity=0.719). ΔLVESV6 had fair agreement with HCCEP (κ=0.391, p < 0.001). CONCLUSION: ΔLVESV6 is the most useful echocardiographic CRT response criterion for the prediction of 1-year HCCEP.
Cardiac Resynchronization Therapy* ; Discrimination (Psychology) ; Echocardiography ; Heart ; Heart Failure ; Hospitalization ; Humans ; Male ; Mitral Valve Insufficiency ; Mortality ; Stroke Volume*

Congestive heart failure is a major cause of morbidity and mortality as well as a major health care cost in the developed world. Despite the introduction of highly effective heart failure medical therapies and simple devices such as cardiac resynchronization therapy that reduce mortality, improve cardiac function and quality of life, there remains a large number of patients who do not respond to these therapies or whose heart failure progresses despite optimal therapy. For these patients, cardiac transplantation is an option but is limited by donor availability as well as co-morbidities which may limit survival post-transplant. For these patients, left ventricular assist devices (LVADs) offer an alternative that can improve survival as well as exercise tolerance and quality of life. These devices have continued to improve as technology has improved with substantially improved durability of the devices and fewer post-implant complications. Pump thrombosis, stroke, gastrointestinal bleeding and arrhythmias post-implant have become less common with the newest devices, making destination therapy where ventricular assist device are implanted permanently in patients with advanced heart failure, a reality and an appropriate option for many patients. This may offer an opportunity for long term survival in many patients. As the first of the totally implantable devices are introduced and go to clinical trials, LVADs may be introduced that may truly be alternatives to cardiac transplantation in selected patients. Post-implant right ventricular failure remains a significant complication and better ways to identify patients at risk as well as to manage this complication must be developed.
Arrhythmias, Cardiac ; Cardiac Resynchronization Therapy ; Exercise Tolerance ; Health Care Costs ; Heart Failure ; Heart Transplantation ; Heart-Assist Devices ; Hemorrhage ; Humans ; Mortality ; Quality of Life ; Stroke ; Thrombosis ; Tissue Donors

Heart failure (HF) is an important cardiovascular disease because of its increasing prevalence, significant morbidity, high mortality and rapidly expanding health care costs. The number of HF patients is increasing worldwide and Korea is no exception. Temporal trends of four representative Korean hospitalized HF registries–the Hallym HF study, the Korean Multicenter HF study, the Korean Heart Failure (KorHF) registry and the Korean Acute Heart Failure (KorAHF) registry showed mild survival improvement reflecting overall HF patient care development in Korea despite the increased severity of enrolled patients with higher incidence of multiple comorbidities. Moreover, device therapies such as implantable cardioverter defibrillator and cardiac resynchronization therapy and definitive treatment such as heart transplantation have been increasing in Korea as well. To prevent HF burden increase, it is essential to set up long term effective prevention strategies for better control of ischemic heart disease, hypertension and diabetes, which might be risk factors for HF development. Moreover, proper HF guidelines, performance measures, and performance improvement programs might be necessary to limit HF burden as well.
Cardiac Resynchronization Therapy ; Cardiovascular Diseases ; Comorbidity ; Defibrillators ; Health Care Costs ; Heart Failure* ; Heart Transplantation ; Heart* ; Hospitalization ; Humans ; Hypertension ; Incidence ; Korea* ; Mortality ; Myocardial Ischemia ; Patient Care ; Prevalence ; Risk Factors

Although the estimates from limited studies vary on the proportion of patients with heart failure who also have ventricular dyssynchrony as reflected by a prolonged QRS complex, often in the form of left bundle branch block, the number of such patients is large (27% to 53%) and it is certainly in excess of the rate for the general population. Among these patients, 10% to 15% are candidates for cardiac resynchronization therapy (CRT) via biventricular pacing. Accumulated evidence from randomized controlled studies over the last few years has indicated that significant hemodynamic and clinical improvement is conferred by CRT to the class III or IV heart failure patients with idiopathic or ischemic dilated cardiomyopathy and who also have a low left ventricular ejection fraction (< or =35%) and a wide QRS complex (> or =120-150 ms). Newer data suggest a significant reduction in mortality and heart failure hospitalization, particularly when CRT is combined with an automatic defibrillator backup. This technique has transformed the traditional concepts associated with stimulation of the heart, and it is now being applied not only to restore an appropriate heart rate, but also to change the process of cardiac mechanical activation. Since this treatment must be integrated within a comprehensive and multidisciplinary CHF management program, CRT has altered the medical practice of heart experts in the field of cardiac pacing. Technical advances with percutaneous methods that access the tributaries of the cardiac veins have raised the success rate of implanting left ventricular leads to >90%. Further confirmation from ongoing trials is eagerly awaited, and more data from the studies on this procedure's cost effectiveness are needed before CRT is considered as a prime therapy in the heart failure population.
Bundle-Branch Block ; Cardiac Resynchronization Therapy* ; Cardiomyopathy, Dilated ; Cost-Benefit Analysis ; Defibrillators ; Heart ; Heart Failure ; Heart Rate ; Hemodynamics ; Hospitalization ; Humans ; Mortality ; Stroke Volume ; Veins

We applied cardiac resynchronization therapy (CRT) for desynchronized heart failure patients. We evaluated clinical outcomes including morbidity, mortality, and echocardiographic parameters in 47 patients with implanted CRT in Korea from October 2005 to May 2013. The combined outcomes of hospitalization from heart failure, heart transplantation and death were the primary end point. Median follow-up period was 17.5 months. The primary outcomes listed above occurred in 10 (21.3%) patients. Two patients (4.3%) died after CRT and 8 (17%) patients were hospitalized for recurrent heart failure. Among patients hospitalized for heart failure, 2 (4.3%) patients underwent heart transplantation. The overall free rate of heart failure requiring hospitalization was 90.1% (95% CI, 0.81-0.99) over one year and 69.4% (95% CI, 0.47-0.91) over 3 yr. We observed improvement of the New York Heart Association classification (3.1+/-0.5 to 1.7+/-0.4), decreases in QRS duration (169.1 to 146.9 ms), decreases in left ventricular (LV) end-diastolic (255.0 to 220.1 mL) and end-systolic (194.4 to 159.4 mL) volume and increases in LV ejection fraction (22.5% to 31.1%) at 6 months after CRT. CRT improved symptoms and echocardiographic parameters in a relatively short period, resulting in low mortality and a decrease in hospitalization due to heart failure.
Age Distribution ; Cardiac Resynchronization Therapy/*mortality ; Cardiac Resynchronization Therapy Devices/*statistics & numerical data ; Female ; Heart Failure/diagnosis/*mortality/*prevention & control ; *Hospital Mortality ; Hospitalization/*statistics & numerical data ; Humans ; Longitudinal Studies ; Male ; Middle Aged ; Prevalence ; Prostheses and Implants/statistics & numerical data ; Recurrence ; Republic of Korea/epidemiology ; Risk Factors ; Sex Distribution ; Survival Rate ; Treatment Outcome

Atrial fibrillation (AF) and heart failure (HF) are growing cardiovascular disease epidemics worldwide. There has been an exponential increase in the prevalence of AF and HF correlating with an increased burden of cardiac risk factors and improved survival rates in patients with structural heart disease. AF is associated with adverse prognostic outcomes in HF and is most evident in mild-to-moderate left ventricular (LV) dysfunction where the loss of “atrial kick” translates into poorer quality of life and increased mortality. In the absence of underlying structural heart disease, arrhythmia can independently contribute to the development of cardiomyopathy. Together, these 2 conditions carry a high risk of thromboembolism due to stasis, inflammation and cellular dysfunction. Stroke prevention with oral anticoagulation (OAC) remains a mainstay of treatment. Pharmacologic rate and rhythm control remain limited by variable efficacy, intolerance and adverse reactions. Catheter ablation for AF has resulted in a paradigm shift with evidence indicating superiority over medical therapy. While its therapeutic success is high for paroxysmal AF, it remains suboptimal in persistent AF. A better mechanistic understanding of AF as well as innovations in ablation technology may improve patient outcomes in the future. Refractory cases may benefit from atrioventricular junction ablation and biventricular pacing. The value of risk factor modification, especially with regard to obesity, sleep apnea, hypertension and diabetes, cannot be emphasized enough. Close interdisciplinary collaboration between HF specialists and electrophysiologists is an essential component of good long-term outcomes in this challenging population.
Arrhythmias, Cardiac ; Atrial Fibrillation* ; Cardiac Resynchronization Therapy ; Cardiomyopathies ; Cardiovascular Diseases ; Catheter Ablation ; Cooperative Behavior ; Heart Diseases ; Heart Failure* ; Heart* ; Humans ; Hypertension ; Inflammation ; Mortality ; Obesity ; Prevalence ; Quality of Life ; Risk Factors ; Sleep Apnea Syndromes ; Specialization ; Stroke ; Survival Rate ; Thromboembolism