Percutaneous Coronary Intervention Versus Coronary Artery Bypass Grafting for Revascularization of Left Main Coronary Artery Disease

Owing to a large-jeopardized myocardium, left main coronary artery disease (LMCAD) represents the substantial high-risk anatomical subset of obstructive coronary artery disease.For several decades, coronary artery bypass grafting (CABG) has been the “gold standard” treatment for LMCAD. Along with advances in CABG, percutaneous coronary intervention (PCI) has also dramatically evolved over time in conjunction with advances in the stent or device technology, adjunct pharmacotherapy, accumulated experiences, and practice changes, establishing its position as a safe, reasonable treatment option for such a complex disease. Until recently, several randomized clinical trials, meta-analyses, and observational registries comparing PCI and CABG for LMCAD have shown comparable long-term survival with tradeoffs between early and late risk-benefit of each treatment. Despite this, there are still several unmet issues for revascularization strategy and management for LMCAD. This review article summarized updated knowledge on evolution and clinical evidence on the treatment of LMCAD, with a focus on the comparison of state-of-the-art PCI with CABG.

Exercise capacity and risk of incident atrial fibrillation in healthy adults

Background/Aims@#Atrial fibrillation (AF) is a common arrhythmia and is associated with cardiovascular morbidity and mortality. It is important to identify and control the modifiable risk factors of AF. We aimed to examine the association of exercise capacity with the risk of incident AF within 3 years in healthy subjects. @*Methods@#We evaluated asymptomatic adults who had undergone more than two consecutive health checkups. We included subjects who exhibited normal sinus rhythm on the first health examination and who developed AF on the second or subsequent health examinations. Subjects who underwent cardiopulmonary exercise testing within 3 years before the diagnosis of AF were examined. @*Results@#The study population in the analyses included 428 cases (mean age 58.4 ± 7.6 yr, male 95.6%). There were significant differences in maximal systolic blood pressure (SBP; case 169.4 ± 24.2 vs. control 173.9 ± 22.3 mmHg), peak VO2 (29.5 ± 5.4 vs. 30.4 ± 4.8 mL/kg per minute), and maximal metabolic equivalents (METs; 8.5 ± 1.6 vs. 8.7 ± 1.4) between the two groups. In the multivariable logistic models, adjusted odds ratios were 0.99 for maximal SBP (95% confidence interval [CI] 0.98–0.99), 0.97 for peak VO2 (95% CI 0.95–0.99), and 0.91 for maximal METs (95% CI 0.83–0.98). @*Conclusions@#We demonstrated that poorer exercise capacity was associated with the development of AF in a healthy population. A prospective, systematic trial is necessary to confirm that appropriate exercise training will be beneficial in preventing the development of AF in such patients.

Totally Thoracoscopic Ablation in Patients With Recurrent Atrial Fibrillation After Catheter Ablation

Background@#The objective of this study was to evaluate the efficacy and safety of totally thoracoscopic ablation (TTA) in patients with recurrent atrial fibrillation (AF) after radiofrequency catheter ablation (RFCA). @*Methods@#From February 2012 to May 2020, 460 patients who underwent TTA were classified into two groups: CA (presence of RFCA history, n = 74) and nCA groups (absence of RFCA history, n = 386). Inverse probability of treatment weighting (IPTW) analyses were used to adjust for confounders. The primary endpoint was freedom from the composite of AF, typical atrial flutter, atypical atrial flutter and any atrial tachyarrhythmia, lasting more than 30 seconds during the follow-up. All patients were followed up at 3, 6, and 12 months via electrocardiogram and 24-hour Holter monitoring. @*Results@#Bilateral pulmonary vein isolation (PVI) was conducted in all patients and the conduction block tests were confirmed. In the CA group, difficult PVI occasionally occurred due to structural changes, such as pericardial adhesion and fibrosis of the pulmonary venous structure, caused by a previous catheter ablation. Early complications such as stroke and pacemaker insertion were not different between the two groups. The normal sinus rhythm was maintained in 70.1% (317/460) patients after a median follow-up period of 38.1 months.The IPTW-weighted Kaplan-Meier curves revealed that freedom from AF events at 5 years was 68.4% (95% confidence interval, 62.8–74.5) in the nCA group and 31.2% (95% confidence interval, 16.9–57.5) in the CA group (P < 0.001). In IPTW-weighted Cox regression, preoperative left atrial diameter, persistent or long-standing AF, the presence of congestive heart failure and catheter ablation history were associated with AF events. @*Conclusion@#Patients in the CA group showed a higher recurrence rate of AF than those in the nCA group, while TTA was safely performed in both the groups.

Device treatment of heart failure

The incidence of heart failure (HF) is rapidly increasing, introducing a significant burden and challenges in clinical practice. Non-pharmacological cardiac device therapy has been established as an essential component of optimal HF management, particularly for the prevention of sudden cardiac death and the improvement of HF symptoms, left ventricular (LV) systolic function, quality of life, and eventually survival.Current Concepts: Cardiac resynchronization therapy (CRT) can correct atrioventricular or inter/intraventricular dyssynchrony, thereby improving LV systolic function. Recently, the concept of CRT is being expanded, including His bundle (HB), HB-optimized LV, left bundle branch (LBB), and LBB optimized LV pacing CRTs. Newly introduced CRT approaches by stimulating the cardiac conduction system are expected to correct dyssynchrony better and consequently exhibit better CRT outcomes than the conventional biventricular pacing CRT. The current versions of implantable cardioverter-defibrillators (ICDs) or CRT devices can continuously monitor multiple biosignals. CRT/ICD can calculate a single index by combining these multiple bio-signal data for early detection of HF aggravation. Recently, subcutaneous and transvenous ICDs showed comparable safety and efficacy in HF patients. In drug-refractory HF patients without LV dyssynchrony, cardiac contractility modulation therapy provides some promising results.Discussion and Conclusion: Recent technological advancements have improved the efficacy and safety of cardiac device therapy. Therefore, cardiac device therapy should be used more actively to manage HF patients better.

Rotational mechanical dilator sheaths for effective transvenous lead extraction

Background@#An exponential rise in clinical demand for cardiac implantable electronic device (CIED) therapy is observed all over the world due to the rapidly expanding lifespan. Accordingly, appropriate lead management including lead extraction is becoming increasingly essential components for the comprehensive care of patients with various CIEDs.Main body: With a high success rate and a low complication rate, transvenous lead extraction (TLE) has now been established as first-line therapy for lead extraction. However, TLE is often challenging when there are heavily calcified fibrous adhesions between leads and cardiovascular structures. Recently, rotational mechanical dilator (RMD) sheaths were introduced to resolve this issue and facilitate TLE procedure. There are two types of commercially available RMD sheaths, Evolution ® systems and TightRail™. Thorough knowledge of the proper use of the RMD devices is essential to increase success rate and to reduce complications of TLE. In the present review, mechanical features, various tech‑ niques, and clinical data of RMD sheaths will be described. @*Conclusion@#According to recent advancement of device technology, the clinical outcomes of TLE using the RMD sheaths are continuously improving. However, as the RMD sheath is a potentially aggressive tool, special care should be taken when used in patients with longer lead ages.

Effectiveness of the Early Staged Hybrid Approach for Treatment of Symptomatic Atrial Fibrillation: the Electrophysiology Study Could Be Deferred?

Background@#The efficacy of catheter ablation for persistent atrial fibrillation (AF) remains suboptimal. A hybrid approach of catheter ablation combined with totally thoracoscopic surgical ablation can improve outcomes. In this study, we evaluated the efficacy of the early staged hybrid procedure in hospital stay after totally thoracoscopic ablation compared to the stand-alone totally thoracoscopic ablation. @*Methods@#Patients who underwent totally thoracoscopic ablation from February 2012 to December 2018 were included in this study. We compared the outcomes of the totally thoracoscopic ablation only group versus the early staged hybrid procedure group. The primary outcome was recurrence of atrial tachyarrhythmia after three months of blanking period. The secondary outcome was repeated unplanned additional electrophysiology study and catheter ablation due to atrial tachyarrhythmia recurrence. @*Results@#A total of 306 patients (mean age, 56.8 ± 8.5 years; 278 [90.8%] males) was included in the study, with 81 patients in the early staged hybrid group and 225 patients in the standalone totally thoracoscopic ablation only group. The mean follow-up duration was 30.0 months. Overall arrhythmia-free survival showed no significant difference between the two groups (log-rank P = 0.402). There was no significant difference in the rate of repeat procedure between the two groups (log-rank = 0.11). @*Conclusion@#The early staged hybrid procedure after thoracoscopic ablation could not improve the outcome of recurrence of atrial tachyarrhythmia. The second stage of electrophysiology study could be deferred to patients with recurrence of atrial tachyarrhythmia during follow up after totally thoracoscopic ablation.

Sinus of Valsalva Thrombosis Detected on Computed Tomography after Transcatheter Aortic Valve Replacement

Background and Objectives@#Leaflet thrombosis after transcatheter aortic valve replacement (TAVR) has been reported recently, whereas thrombus formation in sinus of Valsalva has yet to be fully evaluated. This study describes clinical and cardiac computed tomography (CT) findings of patients with sinus of Valsalva thrombosis. @*Methods@#Between March 2011 and Aug 2019, 192 patients underwent cardiac CT after TAVR. After a retrospective review of CT images, 9 patients (82 years, male:female=2:7) who had sinus of Valsalva thrombosis identified by cardiac CT were selected for this study. Patient demographics, interval between TAVR and cardiac CT scan, location and CT attenuation of sinus of Valsalva thrombosis, and presence of concurrent leaflet thrombosis were evaluated. @*Results@#The median interval between TAVR and cardiac CT was 11 days. Sinus of Valsalva thrombosis was frequently detected in the non-coronary sinus (89%, 8/9), and predominantly located in the bottom of the sinus extending upward towards the sinotubular junction. Three patients had concomitant leaflet thrombosis, and 3 patients had subclinical embolic stroke noted on brain magnetic resonance imaging. All patients had been prescribed aspirin and clopidogrel after TAVR for at least 6 months without anticoagulants. @*Conclusions@#Cardiac CT after TAVR can detect sinus of Valsalva thrombosis, and attention should be paid to this potential source of subsequent systemic embolization.

Catheter Ablation is Effective for Recovery from Sinus Node Dysfunction in Patients with Atrial Fibrillation, But Close Monitoring is Still Needed

No abstract available.

Percutaneous Coronary Intervention and Coronary Artery Bypass Grafting for the Treatment of Left Main Coronary Artery Disease

Severe stenosis of the left main coronary artery (LMCA) generally occurs as a result of atherosclerosis and compromises the blood supply to a wide area of myocardium, thereby increasing the risk of serious adverse cardiac events. Current revascularization strategies for patients with significant LMCA disease include coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI), both of which have a range of advantages and disadvantages. In general, PCI is associated with a lower rate of periprocedural adverse events and provides more rapid recovery, while CABG provides more durable revascularization. Most clinical trials comparing PCI and CABG for the treatment of LMCA disease have shown PCI to be non-inferior to CABG with respect to mortality and the serious composite outcome of death, myocardial infarction, or stroke in patients with low-to-intermediate anatomical complexities. Remarkable advancements in PCI standards, including safer and more effective stents, adjunctive intravascular imaging or physiologic evaluation, and antithrombotic treatment, may have contributed to these favorable results. This review provides an update on the current management of LMCA disease with an emphasis on clinical data and academic and clinical knowledge that supports the use of PCI in an increasing proportion of patients with LMCA disease.

Percutaneous Coronary Intervention and Coronary Artery Bypass Grafting for the Treatment of Left Main Coronary Artery Disease

Severe stenosis of the left main coronary artery (LMCA) generally occurs as a result of atherosclerosis and compromises the blood supply to a wide area of myocardium, thereby increasing the risk of serious adverse cardiac events. Current revascularization strategies for patients with significant LMCA disease include coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI), both of which have a range of advantages and disadvantages. In general, PCI is associated with a lower rate of periprocedural adverse events and provides more rapid recovery, while CABG provides more durable revascularization. Most clinical trials comparing PCI and CABG for the treatment of LMCA disease have shown PCI to be non-inferior to CABG with respect to mortality and the serious composite outcome of death, myocardial infarction, or stroke in patients with low-to-intermediate anatomical complexities. Remarkable advancements in PCI standards, including safer and more effective stents, adjunctive intravascular imaging or physiologic evaluation, and antithrombotic treatment, may have contributed to these favorable results. This review provides an update on the current management of LMCA disease with an emphasis on clinical data and academic and clinical knowledge that supports the use of PCI in an increasing proportion of patients with LMCA disease.

Efficacy of Cardiac Resynchronization Therapy Using Automated Dynamic Optimization and Left Ventricular-only Pacing

BACKGROUND: Although device-based optimization has been developed to overcome the limitations of conventional optimization methods in cardiac resynchronization therapy (CRT), few real-world data supports the results of clinical trials that showed the efficacy of automatic optimization algorithms. We investigated whether CRT using the adaptive CRT algorithm is comparable to non-adaptive biventricular (BiV) pacing optimized with electrocardiogram or echocardiography-based methods. METHODS: Consecutive 155 CRT patients were categorized into 3 groups according to the optimization methods: non-adaptive BiV (n = 129), adaptive BiV (n = 11), and adaptive left ventricular (LV) pacing (n = 15) groups. Additionally, a subgroup of patients (n = 59) with normal PR interval and left bundle branch block (LBBB) was selected from the non-adaptive BiV group. The primary outcomes included cardiac death, heart transplantation, LV assist device implantation, and heart failure admission. Secondary outcomes were electromechanical reverse remodeling and responder rates at 6 months after CRT. RESULTS: During a median 27.5-month follow-up, there was no significant difference in primary outcomes among the 3 groups. However, there was a trend toward better outcomes in the adaptive LV group compared to the other groups. In a more rigorous comparisons among the patients with normal PR interval and LBBB, similar patterns were still observed. CONCLUSION: In our first Asian-Pacific real-world data, automated dynamic CRT optimization showed comparable efficacy to conventional methods regarding clinical outcomes and electromechanical remodeling.

Transseptal Transcatheter Mitral Valve-in-valve Replacement for a Failed Bioprosthetic Mitral Valve

No abstract available.

Early experience and favorable clinical outcomes of everolimus-eluting bioresorbable scaffolds for coronary artery disease in Korea

BACKGROUND/AIMS: Compared with metallic drug-eluting stents (DES), bioresorbable vascular scaffolds (BVS) may further improve long-term outcomes of percutaneous coronary intervention (PCI) in patients with coronary artery disease. We report our early experience with BVS in Korea. METHODS: We evaluated 105 consecutive patients with BVS implanted at Asan Medical Center, Korea between October 21, 2015 and June 3, 2016. Angiographic results, and in-hospital and 6-month clinical outcomes were assessed. RESULTS: A total of 134 BVS were implanted to treat 115 lesions. The mean age was 62 ± 10.5 years; 85 patients (81%) were males, 26 patients (25%) were presented with acute coronary syndrome. Among 115 lesions treated with BVS, 76 (66.1%) were B2/C type, 27 (23.5%) were bifurcation lesions, and four (3.5%) were chronic total occlusion. Pre-dilation and post-dilation using high-pressure non-compliant balloon was performed in 104 lesions (90.4%) and 113 lesions (98.2%), respectively. During the procedure, intravascular imaging was used for all patients (100%; intravascular ultrasound 89 and optical coherence tomography 40 patients). Device success rate was 100%. In-segment and in-scaffold acute again were 1.1 ± 0.6 and 1.3 ± 0.5 mm, respectively. Periprocedural myocardial infraction occurred in four patients (3.8%). No deaths, stent thrombosis, or urgent revascularizations occurred either during hospitalization or the follow-up period. CONCLUSIONS: In this single-center experience, implantation of BVS with intravascular imaging support was feasible and early clinical outcomes were excellent. Evaluation of long-term efficacy and safety of BVS and its feasibility in clinical use for a broader range of lesions is warranted.

Implantable Cardioverter-Defibrillator of Korean Patients in a Single Center Registry

BACKGROUND AND OBJECTIVES: The safety and efficacy of implantable cardioverter-defibrillator (ICD) for Korean is unclear. We investigated the clinical characteristics and outcomes of Korean patients undergoing ICD for primary or secondary prevention. MATERIALS AND METHODS: From October 1999 to December 2016, 396 cases (365 patients) of ICD implantation were performed: Baseline characteristics, procedural findings, and clinical outcome data were collected retrospectively from our ICD registry. The primary outcome was composite of cardiac death, appropriate shock or antitachycardia pacing. RESULTS: Among 365 patients, 91 patients (25.9%) had ICD for primary prevention and 274 patients (75.1%) were for secondary prevention (51.2±17.10 years, male was 80.8%). The median follow-up period was 3.1 years (interquartile range: 1.6–6.0 days). The most prevalent etiology was dilated cardiomyopathy (46.2%) in the primary prevention and idiopathic ventricular tachycardia or fibrillation (24.4%) in the secondary prevention. The primary outcome was noted in 28.6% of the primary prevention and 33.2% of the secondary prevention (P=0.44). The rate of cardiac death was 2.2% in the primary prevention and 1.8% in the secondary prevention (P=1.00). The hospitalization due to heart failure was higher in the primary prevention compared with the secondary prevention (23.1% versus 13.5%, P=0.03). ICD therapy occurred in 134 patients (36.7%). Among them, 60 patients (44.8% of ICD therapy) experienced inappropriate shock. The most common cause of inappropriate shock was atrial fibrillation of flutter (AF/AFL). CONCLUSION: The clinical efficacy and safety of ICD in Korean is consistent with the data from Western countries.

Coronary Artery Bypass Grafting vs. Drug-Eluting Stent Implantation for Multivessel Disease in Patients with Chronic Kidney Disease

BACKGROUND AND OBJECTIVES: There is currently a limited amount of data that demonstrate the optimal revascularization strategy for chronic kidney disease (CKD) patients with multivessel coronary artery disease (CAD). We compared the long-term outcomes of percutaneous coronary intervention (PCI) with drug-eluting stents (DES) versus coronary artery bypass graft surgery (CABG) for multivessel CAD in patients with CKD. SUBJECTS AND METHODS: We analyzed 2108 CKD patients (estimated glomerular filtration rate <60 mL/min/1.73 m²) with multivessel CAD that were treated with PCI with DES (n=1165) or CABG (n=943). The primary outcome was a composite of all causes of mortality, myocardial infarction, or stroke. The mean age was 66.9±9.1 years. RESULTS: Median follow-up duration was 41.4 (interquartile range 12.1-75.5) months. The primary outcome occurred in 307 (26.4%) patients in the PCI group compared with 304 (32.2%) patients in the CABG group (adjusted hazard ratio [HR], 0.941; 95% confidence interval [CI], 0.79–1.12; p=0.493). The two groups exhibited similar rates of all-cause mortality (adjusted HR, 0.91; 95% CI, 0.77–1.09; p=0.295), myocardial infarction (adjusted HR, 1.86; 95% CI, 0.85–4.07; p=0.120) and stroke (3.2% vs. 4.8%; HR, 0.93; 95% CI, 0.57–1.61; p=0.758). However, PCI was associated with significantly increased rates of repeat revascularization (adjusted HR, 4.72; 95% CI, 3.20–6.96; p<0.001). CONCLUSION: Among patients with CKD and multivessel CAD, PCI with DES when compared with CABG resulted in similar rates of composite outcome of mortality from any cause, MI, or stroke; however, a higher risk of repeat revascularization was observed.

Comparison of Supervised Hospital-based versus Educated Home-based Exercise Training in Korean Heart Failure Patients

BACKGROUND AND OBJECTIVES: Although many clinical trials have shown that exercise training (ET) improves functional capacity and clinical outcomes in heart failure (HF) patients, data comparing supervised hospital-based and educated home-based ET in HF patients is lacking. SUBJECTS AND METHODS: This was a single-center, non-randomized, prospective study of 82 HF patients with reduced ejection fraction (≤40%) who completed ET. The hospital-based group (n=30) underwent supervised ET at 60% of peak oxygen consumption (VO₂), while a physiotherapist-educated group (n=52) exercised at home without monitoring. The 2 groups were compared before and after the 3-month ET program with respect to functional capacity, quality of life (QOL), and cardiac events (all-cause mortality or hospitalization with worsening HF). RESULTS: After ET, peak VO₂ increased in the hospital-based group (19.4±4.4 to 21.4±4.3 mL/min/kg, p=0.006) and remained unchanged in the home-based group (18.9±4.6 to 18.4±4.6 mL/min/kg, p=0.660). The change in peak VO₂ after ET was greater in the hospital-based group compared to the home-based group by 2.5 mL/min/kg (p=0.014). QOL improved in the hospital-based group (43.1±18.0 to 28.1±21.6, p=0.003). During one year of follow-up, a comparison of the 2 groups did not reveal a statistical difference in cardiac events (hazard ratio, 0.66; 95% confidence interval, 0.2–2.8; p=0.570). CONCLUSION: Hospital-based ET was beneficial for HF patients, improving functional capacity and QOL. However, no significant advantages were observed in terms of a composite endpoint compared to home-based ET. Further investigations are required to address the effects and roles of the 2 ET programs for HF patients.

Bioresorbable Vascular Scaffold Korean Expert Panel Report

Bioresorbable vascular scaffold (BRS) is an innovative device that provides structural support and drug release to prevent early recoil or restenosis, and then degrades into nontoxic compounds to avoid late complications related with metallic drug-eluting stents (DESs). BRS has several putative advantages. However, recent randomized trials and registry studies raised clinical concerns about the safety and efficacy of first generation BRS. In addition, the general guidance for the optimal practice with BRS has not been suggested due to limited long-term clinical data in Korea. To address the safety and efficacy of BRS, we reviewed the clinical evidence of BRS implantation, and suggested the appropriate criteria for patient and lesion selection, scaffold implantation technique, and management.

Interrelated Atrioventricular Reentrant Tachycardia and Idiopathic Left Ventricular Tachycardia in a Patient with Manifested Bystander Accessory Pathway

Double tachycardia is defined as the coexistence of supraventricular tachycardia (SVT) and ventricular tachycardia (VT). In clinical practice, incidentally encountered double tachycardia is difficult to diagnose during electrophysiology study without prior documentation of both tachycardias. SVT can be confused with VT because SVT sometimes show an aberrant conduction depending on heart rate. In the present case, a patient with Wolff-Parkinson-White syndrome exhibited atrioventricular reentrant tachycardia (AVRT) via a concealed bypass tract and idiopathic left ventricular tachycardia (ILVT), which were difficult to discriminate because of their similar cycle length and interrelationship.

Cardiac Resynchronization Therapy Device Implantation in a Patient with Cardiogenic Shock under Percutaneous Mechanical Circulatory Support

65-year-old woman was admitted to our hospital with acute decompensated heart failure with reduced left ventricular ejection fraction and severe mitral regurgitation. Electrocardiography revealed a typical left bundle branch block and atrial fibrillation. Her condition deteriorated despite administering high-doses of inotropes and vasopressors. Pending a decision to therapy, venoarterial extracorporeal membrane oxygenation (ECMO) was performed when the patient underwent a cardiogenic shock. Although the hemodynamic status stabilized with ECMO support, weaning the patient from ECMO was not possible. Thus, we decided to perform cardiac resynchronization with defibrillator implantation as a “rescue” therapy. Five days post-implantation, the patient was successfully weaned from ECMO.

The Absence of Atrial Contraction as a Predictor of Permanent Pacemaker Implantation after Maze Procedure with Cryoablation

BACKGROUND: The absence of atrial contraction (AC) after the maze procedure has been reported to cause subsequent annular dilatation and to increase the risk of embolic stroke. We hypothesized that the lack of AC could increase the risk of permanent pacemaker (PPM) implantation in patients undergoing the maze procedure. METHODS: In 376 consecutive patients who had undergone a cryo-maze procedure and combined valve operation, recovery of AC was assessed at baseline and at immediate (≤2 weeks), early (≤1 year, 4.6±3.8 months), and late (>1 year, 3.5±1.1 years) postoperative stages. RESULTS: With a median follow-up of 53 months, 10 patients underwent PPM implantation. Seven PPM implants were for sinus node dysfunction (pauses of 9.6±2.4 seconds), one was for marked sinus bradycardia, and two were for advanced/complete atrioventricular block. The median (interquartile range) time to PPM implantation was 13.8 (0.5–68.2) months. Our time-varying covariate Cox models showed that the absence of AC was a risk factor for PPM implantation (hazard ratio, 11.92; 95% confidence interval, 2.52 to 56.45; p=0.002). CONCLUSION: The absence of AC may be associated with a subsequent risk of PPM implantation.