The impact of supraventricular arrhythmias on the outcomes of guideline-compliant implantable cardioverter defibrillator programming.

INTRODUCTION: Several implantable cardioverter defibrillators (ICD) programming strategies are applied to minimize ICD therapy, especially unnecessary therapies from supraventricular arrhythmias (SVA). However, it remains unknown whether these optimal programming recommendations only benefit those with SVAs or have any detrimental effects from delayed therapy on those without SVAs. This study aims to assess the impact of SVA on the outcomes of ICD programming based on 2015 HRS/EHRA/APHRS/SOLAECE expert consensus statement and 2019 focused update on optimal ICD programming and testing guidelines. METHODS: Consecutive patients who underwent ICD insertion for primary prevention were classified into four groups based on SVA status and ICD programming: (1) guideline-concordant group (GC) with SVA, (2) GC without SVA, (3) nonguideline concordant group (NGC) with SVA, and (4) NGC without SVA. Cox proportional hazard models were analyzed for freedom from ICD therapies, shock, and mortality. RESULTS: Seven hundred and seventy-two patients (median age, 64 years) were enrolled. ICD therapies were the most frequent in NGC with SVA (24.0%), followed by NGC without SVA (19.9%), GC without SVA (11.6%), and GC with SVA (8.1%). Guideline concordant programming was associated with 68% ICD therapy reduction (HR 0.32, p = .007) and 67% ICD shock reduction (HR 0.33, p = .030) in SVA patients and 44% ICD therapy reduction in those without SVA (HR 0.56, p = .030). CONCLUSION: Programming ICDs in primary prevention patients based on current guidelines reduces therapy burden without increasing mortality in both SVA and non-SVA patients. A greater magnitude of reduced ICD therapy was found in those with supraventricular arrhythmias.

Atrial fibrillation burden and subsequent heart failure events in patients with cardiac resynchronization therapy devices.

BACKGROUND: Atrial fibrillation (AF) and heart failure (HF) often coexist but little is known on how AF burden associates with subsequent episodes of HF. OBJECTIVE: The aim of this study was to quantitatively assess the short- and long-term association of AF burden with subsequent episodes of HF events in patients with reduced ejection fraction. METHODS: Patients with cardiac resynchronization therapy (CRT) devices with at least 90 days of device data were included in the study. Time-dependent Cox regression with a 7-day window was used to evaluate the association of short- and long-term AF burden with subsequent HF events. Each patient with HF was matched to two control patients without an HF event based on age, gender, year of implant and CRT defibrillation capability. RESULTS: In our cohort with 2:1 matching (N = 549), 183 patients developed HF events and 275 (50.1%) had AF over an average follow-up of 24 ± 11 months. A 1-hour increase in short-term AF burden was associated with a 3% increased risk of HF events (HR, 1.034; 95% confidence interval [CI], 1.012-1.056; P = .01; HR for 24-hour = 2.23). In contrast, the association between long-term AF burden and subsequent HF events was not statistically significant (HR, 1.009; 95% CI, 0.992-1.026; P = .373). CONCLUSION: A 24-hour increase in AF burden is associated with a more than two-fold increased risk of HF events over the subsequent week while the long-term AF burden is not significantly associated with HF events.

Safety and efficacy of apixaban versus warfarin in patients with end-stage renal disease: Meta-analysis.

BACKGROUND: At the present, apixaban is the only nonvitamin K oral anticoagulant approved by the Food and Drug Administration for use with patients with creatinine clearance <15 mL/min or end-stage renal disease (ESRD). However, the recommendations are based on pharmacokinetic and pharmacodynamic data and there was lack of clinical trial evidence. We aimed to assess safety and efficacy of apixaban in patients with advanced chronic kidney disease (CKD) or ESRD. METHODS: Databases were searched through November 2017. Studies that reported incidence or odd ratios of bleeding complications or thromboembolic events in the use of apixaban in patients with CKD stage 4-5 or ESRD on dialysis were included. Effect estimates from the individual study were extracted and combined using random-effect, generic inverse variance method of DerSimonian and Laird. RESULTS: Five studies were included into the analysis consisting of 43,850 patients in observational cohort studies. The majority of patients (87%) used apixaban for atrial fibrillation. The pooled estimated incidence of any bleeding complications on apixaban was 17.4% (95% confidence interval [CI]: 13.0%-23.0%). Compared to warfarin, apixaban was significantly associated with reduced risk of major bleeding (pooled odds ratio [OR], 0.42; 95% CI, 0.28-0.61). In studies in ESRD patients on dialysis, the pooled OR of major bleeding was 0.27 (95% CI, 0.07-0.95). There was no significant difference in risk of thromboembolic events in advanced CKD or ESRD patients on apixaban versus vitamin K antagonists (pooled OR, 0.56; 95% CI, 0.23-1.39). CONCLUSIONS: Among patients with advanced CKD and ESRD, the use of apixaban was associated with lower risk of major bleeding compared to warfarin, and was found to be relatively effective with no excess risk of thromboembolic events.

Associations of sleep quality with incident atrial fibrillation: a meta-analysis.

BACKGROUND: The strong relationship between sleep apnoea and atrial fibrillation (AF) is well known. However, it remains unclear whether the sleep quality is related with AF. AIM: To evaluate the associations of sleep duration, insomnia and frequent awakening with AF. METHODS: A systematic review was conducted in MEDLINE, EMBASE, Cochrane databases from inception through September 2017 to identify studies that evaluate the risk of AF in adults with short sleep duration, long sleep duration, insomnia and/or frequent awakening. Effect estimates from the individual study were extracted and combined using random-effect, generic inverse variance method of DerSimonian and Laird. RESULTS: Ten observational studies (14 296 314 patients) were enrolled. The pooled odds ratios (ORs) of AF in individuals with short sleep (<6 h) and long sleep (>8 h) were 1.20 (95% confidence interval (CI) 0.93-1.55, I2 = 66%) and 1.24 (95% CI 0.96-1.62, I2 = 58%), respectively. There was no association between increase in sleep duration and AF, with a pooled OR of 0.97 (95% CI 0.84-1.12, I2 = 0%). However, there were significant associations of AF with insomnia and frequent awakening, with pooled ORs of 1.30 (95% CI 1.26-1.35, I2 = 3%) and 1.36 (95% CI 1.13-1.63, I2 = 55%), respectively. CONCLUSIONS: Our findings suggest an absence in association between AF and sleep duration but reveal the potential association between AF and both insomnia and frequent nocturnal awakening. As such, the further studies on association of AF and sleep qualities are warranted.

Assessment of Diastolic Function in Hypertrophic Cardiomyopathy by Computed Tomography-Derived Analysis of Left Ventricular Filling.

OBJECTIVES: Hypertrophic cardiomyopathy (HCM) is characterized by diastolic dysfunction, which is difficult to assess by noninvasive methods. We hypothesized that measurement of simultaneous left ventricular (LV) and left atrial (LA) volume changes by cardiac computed tomography would be useful in the assessment of diastolic function in HCM. METHODS: We studied 21 patients with HCM and 21 age-matched controls. The LA and LV volumes were calculated and early and late diastolic volume changes derived. RESULTS: The HCM patients had significantly larger LA volumes and reduced LA total emptying fraction (30 ± 7% vs 42 ± 6%; P < 0.0001). Conduit volume was increased (30 ± 6 vs 22 ± 4 mL/m; P < 0.0001) and contributed a significantly higher proportion of total LV diastolic filling, suggesting that passive filling of the LV compensates for LA dysfunction, but at the expense of increased pulmonary filling pressure. CONCLUSIONS: This study suggests that simultaneous depiction of computed tomography-derived LV and LA volume changes can characterize diastolic dysfunction in HCM.

The role of catheter ablation in the management of ventricular tachycardia.

The treatment strategy for ventricular tachycardia (VT) is guided by patient symptoms, the risk of sudden death estimated by VT mechanism and underlying cardiac structure, and the risk vs. benefit ratio of potential therapies. Over the last few decades, catheter ablation has emerged as the primary treatment of idiopathic VT and become an important management strategy in reducing VT burden in patients with structural heart disease. This article reviews the technique and outcomes of catheter ablation for ventricular arrhythmias as well as potential future directions for this procedure.

Electroanatomic Correlates of Depolarization Abnormalities in Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy.

BACKGROUND: Epsilon waves and other depolarization abnormalities in the right precordial leads are thought to represent delayed activation of the right ventricular outflow tract in arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C). However, no study has directly correlated cardiac electrical activation with the surface ECG findings in ARVD/C. METHODS AND RESULTS: Thirty ARVD/C patients (mean age 32.7 ± 11.2 years, 16 men) underwent endocardial and epicardial electroanatomical activation mapping in sinus rhythm. Twelve-lead ECGs were classified into 5 patterns: (1) normal QRS (11 patients); (2) terminal activation delay (TAD) (3 patients); (3) incomplete right bundle branch block (IRBBB) (5 patients); (4) epsilon wave (5 patients); (5) complete right bundle branch block (CRBBB) (6 patients). Timing of local ventricular activation and extent of scar was then correlated with surface QRS. Earliest endocardial and epicardial RV activation occurred on the mid anteroseptal wall in all patients despite the CRBBB pattern on ECG. Total RV activation times increased from normal QRS to prolonged TAD, IRBBB, epsilon wave, and CRBBB, respectively (103.9 ± 5.6, 116.3 ± 6.5, 117.8 ± 2.7, 146.4 ± 16.3, and 154.3 ± 6.3, respectively, P < 0.05). The total epicardial scar area (cm(2) ) was similar among the different ECG patterns. Median endocardial scar burden was significantly higher in patients with epsilon waves even compared with patients with CRBBB (34.3 vs. 11.3 cm(2) , P < 0.01). Timing of epsilon wave corresponded to activation of the subtricuspid region in all patients. CONCLUSION: We found that epsilon waves are often associated with severe conduction delay and extensive endocardial scarring in addition to epicardial disease. The timing of epsilon waves on surface ECG correlated with electrical activation of the sub-tricuspid region.

"2 for 1 Phenomenon" on Implantable Cardioverter Defibrillator Intracardiac Tracing.

"2 for 1 phenomenon" is simultaneous anterograde conduction over the fast and slow pathways of the atrioventricular (AV) nodal pathway, leading to a double ventricular response from each atrial beat. This phenomenon can initiate AV nodal reentrant tachycardia (AVNRT). The unique induction of AVNRT was observed in a patient with an implantable cardioverter defibrillator in our case. Minimal to no retrograde invasion of the slow pathway from the anterogradely conducted fast pathway depolarization is the most accepted explanation.

Atypical atrioventricular nodal reentrant tachycardia: prevalence, electrophysiologic characteristics, and tachycardia circuit.

AIMS: This study aimed at assessing the prevalence, electrophysiologic characteristics, and mechanism of atypical atrioventricular nodal reentrant tachycardia (AVNRT). METHODS AND RESULTS: We studied 925 consecutive patients with AVNRT. Atrial-His (AH) and His-atrial (HA) intervals were measured during atypical AVNRT (HA > 70 ms), and compared with measurements in 34 patients with typical (slow-fast) AVNRT. Assuming that conduction velocity over the fast pathway is similar in the anterograde and retrograde directions, the AH interval during the fast-slow form should be smaller than the HA during slow-fast. Atypical AVNRT was diagnosed in 59 patients (6.4%), median age 50 years (range 19-79 years), and 37 (59.7%) of them female. Fast-slow AVNRT was diagnosed in 44 patients (74.5%), and slow-slow AVNRT in 9 patients (15.2%). The remaining six patients (10.2%) could not be reliably classified due to inconsistent AH, and HA/AH patterns or variable intervals. Tachycardia induction with anterograde conduction jumps was seen in two patients with the fast-slow, and in three patients with slow-slow or intermediate forms. Atrial-His in the fast-slow group was significantly longer than HA in the slow-fast group, 99.7 ± 40.5 ms vs. 45.8 ± 7.7 ms, P < 0.001. Tachycardia cycle length was longer in fast-slow compared with slow-fast, 379.1 ± 68.5 ms vs. 317.1 ± 42.8 ms, P < 0.001. CONCLUSION: Of AVNRT cases, 6.4% are atypical and may display patterns that do not necessarily correspond to the fast-slow or slow-slow conventional types. Atypical fast-slow and typical AVNRT do not appear to utilize the same limb for fast conduction.

Lead extraction experience with high frequency excimer laser.

BACKGROUND: A higher frequency Excimer laser sheath using an 80-Hz pulse repetitive rate was approved by the Food and Drug Administration in April 2012. We reported our initial clinical experience with a high-frequency Excimer laser sheath and compared it with lower-frequency laser sheaths which have been previously used. METHODS: In this single center, retrospective cohort study, we evaluated patients who underwent lead extraction from December 2008 to May 2013. Those who underwent lead removal without using a laser sheath or with approaches other than subclavian were excluded. Primary endpoints included total laser time, number of pulses, and complications. Data on clinical characteristics, lead type, indications, and outcomes were prospectively collected and analyzed. RESULTS: A total of 427 patients were included in the study (72.6% male; age 67.9 ± 15.23 years). Lower frequency and higher frequency laser sheaths were used in 315 and 112 patients, respectively. A total of 821 leads were removed with 765 leads (93.2%) extracted using the Excimer laser sheath. Lead age was 5.71 ± 4.96 years. Complete extraction was seen in all patients. A higher-frequency laser sheath was associated with a lower laser time and a lower total number of laser pulses even after adjustments for the number of leads, type of leads, and lead age. In the higher frequency group, mortality rate was 0.9% and minor complication rate was 3.6%. CONCLUSIONS: When compared with the lower-frequency laser sheath, the higher-frequency laser sheath requires less laser times and more efficient amount of pulses for lead extraction with comparable success rate. Due to the rarity of major and minor complications, no statistical significance was found between the two groups.

Protection from outpatient sudden cardiac death following ICD removal using a wearable cardioverter defibrillator.

BACKGROUND: An implantable cardioverter defibrillator (ICD) is effective in preventing sudden cardiac death (SCD). Once an ICD is removed and reimplantation is not feasible, a wearable cardioverter defibrillator (WCD) may be an alternative option. We determined the effectiveness of WCD for SCD prevention in patients who were discharged after ICD removal. METHODS: A retrospective study was conducted on all WCD (LifeVest, ZOLL, Pittsburgh, PA, USA) patients who underwent ICD removal due to cardiac device infections (CDIs) at two referral centers between January 1, 2005 and December 31, 2009. Clinical characteristics, device information, and WCD data were analyzed. Sudden cardiac arrest was defined as all sustained ventricular tachycardia (VT) and ventricular fibrillation occurring within a single 24-hour period. RESULTS: Ninety-seven patients (mean age 62.8 ± 13.3, male 80.4%) were included in the study. The median duration of antibiotic use was 14.7 days (interquartile range [IQR] 10-30). The median daily WCD use was 20 hours/day and the median length of use was 21 days (IQR 5-47). A total of three patients were shocked by WCD. Two patients had four episodes of sustained VT, successfully terminated by the WCD. A third patient experienced two inappropriate treatments due to oversensitivity of the signal artifact. Three patients experienced sudden death outside the hospital while not wearing the device. Five patients died while hospitalized. CONCLUSION: WCD can prevent SCD, until ICD reimplantation is feasible in patients who underwent device removals for CDI. However, patient compliance is essential for the effective use of this device.

Left main coronary atresia.

Left main coronary artery atresia (LMCAA) is one of the least frequently observed congenital coronary anomalies. We describe a case series of LMCAA, highlighting the clinical presentation, characteristic, and treatment.

Device-device interaction between cardiac implantable electronic devices and continuous-flow left ventricular assist devices.

The current design of an innovative left ventricular assist device (LVAD) makes use of magnetic levitation technology, which enables the rotors of the device to be completely suspended by magnetic force, reducing friction and blood or plasma damage. However, this electromagnetic field can result in electromagnetic interference (EMI), which can interfere with proper functioning of another cardiac implantable electronic device (CIED) in its direct proximity. Approximately 80% of patients with an LVAD have a CIED, most frequently an implantable cardioverter-defibrillator (ICD). Several device-device interactions have been reported, including EMI-induced inappropriate shocks, inability to establish telemetry connection, EMI-induced premature battery depletion, undersensing by the device, and other CIED malfunctions. Unfortunately, additional procedures, including generator exchange, lead adjustment, and system extraction, are frequently required because of these interactions. In some circumstances, the additional procedure might be preventable or avoidable with appropriate solutions. In this article, we describe how EMI from the LVAD impacts the functionality of the CIED and provide possible management options, including manufacturer-specific information, for the current CIEDs (eg, transvenous and leadless pacemakers, transvenous and subcutaneous ICDs, and transvenous cardiac resynchronization therapy pacemakers and ICDs).

Programming of implantable cardioverter defibrillators for primary prevention: outcomes at centers with high vs. low concordance with guidelines.

BACKGROUND: While ICD therapy reduction programming strategies are recommended in current multi-society guidelines, concerns remain about a possible trade-off between the benefits of ICD therapy reduction and failure to treat episodes of ventricular arrhythmias. The study is to evaluate the outcomes of primary prevention patients followed in centers with high and low concordance with the 2015 HRS/EHRA/APHRS/SOLAECE expert consensus statement and 2019 focused update on optimal ICD programming and testing guidelines. METHODS: Consecutive patients with primary prevention ICD implantation from two centers between 2014 and 2016 were included. One center was classified as high guideline concordance center (HGC) with 47% (146/310) of patients with initial ICD concordant with the guidelines, and the other center was classified as low guideline concordance center (LGC) with only 1% (2/178) of patients with guideline-concordant initial ICD programming. Cox proportional hazard models were used to assess risk of first ICD therapy (ATP or shock), first ICD shock, and mortality. RESULTS: A total of 488 patients were included (mean age, 66 ± 13 years). During a mean follow-up of 1.9 ± 0.9 years, patients followed at HGC were 63% less likely to receive any ICD therapy (adjusted HR [aHR] 0.37, 95% CI 0.42-0.99). There were no significant differences in the rate of first ICD shock (aHR 0.72, 95% CI 0.34-1.52) or mortality (aHR 1.19, 95% CI, 0.47-3.05). CONCLUSIONS: Compared to primary prevention patients followed at LGC, primary prevention ICD patients followed at HGC received a significantly lower rate of ICD therapy, mainly from ATP reduction, without a difference in mortality during follow-up.

Worldwide survey on implantation of and outcomes for conduction system pacing with His bundle and left bundle branch area pacing leads.

BACKGROUND: Adoption and outcomes for conduction system pacing (CSP), which includes His bundle pacing (HBP) or left bundle branch area pacing (LBBAP), in real-world settings are incompletely understood. We sought to describe real-world adoption of CSP lead implantation and subsequent outcomes. METHODS: We performed an online cross-sectional survey on the implantation and outcomes associated with CSP, between November 15, 2020, and February 15, 2021. We described survey responses and reported HBP and LBBAP outcomes for bradycardia pacing and cardiac resynchronization CRT indications, separately. RESULTS: The analysis cohort included 140 institutions, located on 5 continents, who contributed data to the worldwide survey on CSP. Of these, 127 institutions (90.7%) reported experience implanting CSP leads. CSP and overall device implantation volumes were reported by 84 institutions. In 2019, the median proportion of device implants with CSP, HBP, and/or LBBAP leads attempted were 4.4% (interquartile range [IQR], 1.9-12.5%; range, 0.4-100%), 3.3% (IQR, 1.3-7.1%; range, 0.2-87.0%), and 2.5% (IQR, 0.5-24.0%; range, 0.1-55.6%), respectively. For bradycardia pacing indications, HBP leads, as compared to LBBAP leads, had higher reported implant threshold (median [IQR]: 1.5 V [1.3-2.0 V] vs 0.8 V [0.6-1.0 V], p = 0.0008) and lower ventricular sensing (median [IQR]: 4.0 mV [3.0-5.0 mV] vs. 10.0 mV [7.0-12.0 mV], p < 0.0001). CONCLUSION: In conclusion, CSP lead implantation has been broadly adopted but has yet to become the default approach at most surveyed institutions. As the indications and data for CSP continue to evolve, strategies to educate and promote CSP lead implantation at institutions without CSP lead implantation experience would be necessary.

2023 HRS/APHRS/LAHRS guideline on cardiac physiologic pacing for the avoidance and mitigation of heart failure.

Cardiac physiologic pacing (CPP), encompassing cardiac resynchronization therapy (CRT) and conduction system pacing (CSP), has emerged as a pacing therapy strategy that may mitigate or prevent the development of heart failure (HF) in patients with ventricular dyssynchrony or pacing-induced cardiomyopathy. This clinical practice guideline is intended to provide guidance on indications for CRT for HF therapy and CPP in patients with pacemaker indications or HF, patient selection, pre-procedure evaluation and preparation, implant procedure management, follow-up evaluation and optimization of CPP response, and use in pediatric populations. Gaps in knowledge, pointing to new directions for future research, are also identified.

2023 HRS/APHRS/LAHRS guideline on cardiac physiologic pacing for the avoidance and mitigation of heart failure.

Cardiac physiologic pacing (CPP), encompassing cardiac resynchronization therapy (CRT) and conduction system pacing (CSP), has emerged as a pacing therapy strategy that may mitigate or prevent the development of heart failure (HF) in patients with ventricular dyssynchrony or pacing-induced cardiomyopathy. This clinical practice guideline is intended to provide guidance on indications for CRT for HF therapy and CPP in patients with pacemaker indications or HF, patient selection, pre-procedure evaluation and preparation, implant procedure management, follow-up evaluation and optimization of CPP response, and use in pediatric populations. Gaps in knowledge, pointing to new directions for future research, are also identified.

Use of Direct Oral Anticoagulant and Outcomes in Patients With Atrial Fibrillation after Transcatheter Aortic Valve Replacement: Insights From the STS/ACC TVT Registry.

Background Clinical evidence on the safety and effectiveness of using direct oral anticoagulants (DOACs) in patients with atrial fibrillation after transcatheter aortic valve replacement (TAVR) remains limited. The aim of this study was to investigate the trends and outcomes of using DOACs in patients with TAVR and atrial fibrillation. Methods and Results Data from the STS/ACC TVT (Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy) Registry was used to identify patients who underwent successful TAVR with preexisting or incident atrial fibrillation who were discharged on oral anticoagulation between January 2013 and May 2018. Patients with a mechanical valve, valve-in-valve procedure, or prior stroke within a year were excluded. The adjusted primary outcome was 1-year stroke events. The adjusted secondary outcomes included bleeding, intracranial hemorrhage, and death. A total of 21 131 patients were included in the study (13 004 TAVR patients were discharged on a vitamin K antagonist and 8127 were discharged on DOACs.) The use of DOACs increased 5.5-fold from 2013 to 2018. The 1-year incidence of stroke was comparable between DOAC-treated patients and vitamin K antagonist-treated patients (2.51% versus 2.37%; hazard ratio [HR], 1.00; 95% CI, 0.81-1.23) whereas DOAC-treated patients had lower 1-year incidence of any bleeding (11.9% versus 15.0%; HR, 0.81; 95% CI, 0.75-0.89), intracranial hemorrhage (0.33% versus 0.59%; HR, 0.54; 95% CI, 0.33-0.87), and death (15.8% versus 18.2%; HR, 0.92; 95% CI, 0.85-1.00). Conclusions In patients with TAVR and atrial fibrillation, DOAC use, when compared with vitamin K antagonists, was associated with comparable stroke risk and significantly lower risks of bleeding, intracranial hemorrhage, and death at 1 year.