Strategies to improve atrioventricular synchrony in patients with a Micra AV leadless pacemaker.

The second generation of transcatheter pacing systems, called Micra AV, can provide atrioventricular (AV) synchronous pacing via a new pacing algorithm relying on sensing mechanical atrial contraction. Several novel programming parameters were introduced to enable AV synchronous pacing, including an A3 window and A4 window as well as a conduction mode switch and an activity mode switch. In addition to several automated features, manual programming optimization of some of the novel parameters is key to improving AV synchrony. A solid knowledge of the features and their programming is essential for electrophysiologists implanting or following patients with Micra AV devices. Differences in programming optimization might partially explain the high variability of AV synchrony published in real-world data reports. This article reviews the key programming parameters of Micra AV. Subsequently, optimal programming recommendations for defined patient profiles are presented. Those were established by consensus within an expert panel comprised of 11 European electrophysiologists from high-volume Micra AV centres. The patient profiles were (1) high degree AV block and slow sinus rhythm; (2) high degree AV block and fast sinus rhythm; and (3) intermittent AV block. The panel recommended to evaluate the mechanical atrial activity on transthoracic echocardiography prior to implant. It was also agreed that Auto A3 Threshold and Tracking Check should be turned off in all patients, AV conduction mode switch should be turned off in all patients with high degree AV block, and the lower rate should be programmed to 50 bpm with exceptions based on individual clinical assessment. Future studies will be useful to evaluate the strength of those recommendations to improve the AV synchrony.

Leadless pacemakers at 5-year follow-up: the Micra transcatheter pacing system post-approval registry.

BACKGROUND AND AIMS: Prior reports have demonstrated a favourable safety and efficacy profile of the Micra leadless pacemaker over mid-term follow-up; however, long-term outcomes in real-world clinical practice remain unknown. Updated performance of the Micra VR leadless pacemaker through five years from the worldwide post-approval registry (PAR) was assessed. METHODS: All Micra PAR patients undergoing implant attempts were included. Endpoints included system- or procedure-related major complications and system revision rate for any cause through 60 months post-implant. Rates were compared through 36 months post-implant to a reference dataset of 2667 transvenous pacemaker patients using Fine-Gray competing risk models. RESULTS: 1809 patients were enrolled between July 2015 and March 2018 and underwent implant attempts from 179 centres in 23 countries with a median follow-up period of 51.1 months (IQR: 21.6-64.2). The major complication rate at 60 months was 4.5% [95% confidence interval (CI): 3.6%-5.5%] and was 4.1% at 36 months, which was significantly lower than the 8.5% rate observed for transvenous systems (HR: .47, 95% CI: .36-.61; P < .001). The all-cause system revision rate at 60 months was 4.9% (95% CI: 3.9%-6.1%). System revisions among Micra patients were mostly for device upgrades (41.2%) or elevated thresholds (30.6%). There were no Micra removals due to infection noted over the duration of follow-up. At 36 months, the system revision rate was significantly lower with Micra vs. transvenous systems (3.2% vs. 6.6%, P < .001). CONCLUSIONS: Long-term outcomes with the Micra leadless pacemaker continue to demonstrate low rates of major complications and system revisions and an extremely low incidence of infection.

Efficacy of a web-based healthcare innovation to advance the quality of life and care of patients with an implantable cardioverter defibrillator (ACQUIRE-ICD): a randomized controlled trial.

AIMS: Modern clinical management of patients with an implantable cardioverter defibrillator (ICD) largely consists of remote device monitoring, although a subset is at risk of mental health issues post-implantation. We compared a 12-month web-based intervention consisting of goal setting, monitoring of patients' mental health-with a psychological intervention if needed-psychoeducational support from a nurse, and an online patient forum, with usual care on participants' device acceptance 12 months after implantation. METHODS AND RESULTS: This national, multi-site, two-arm, non-blinded, randomized, controlled, superiority trial enrolled 478 first-time ICD recipients from all 6 implantation centres in Denmark. The primary endpoint was patient device acceptance measured by the Florida Patient Acceptance Survey (FPAS; general score range = 0-100, with higher scores indicating higher device acceptance) 12 months after implantation. Secondary endpoints included symptoms of depression and anxiety. The primary endpoint of device acceptance was not different between groups at 12 months [B = -2.67, 95% confidence interval (CI) (-5.62, 0.29), P = 0.08]. Furthermore, the secondary endpoint analyses showed no significant treatment effect on either depressive [B = -0.49, 95% CI (-1.19; 0.21), P = 0.17] or anxiety symptoms [B = -0.39, 95% CI (-0.96; 0.18), P = 0.18]. CONCLUSION: The web-based intervention as supplement to usual care did not improve patient device acceptance nor symptoms of anxiety and depression compared with usual care. This specific web-based intervention thus cannot be recommended as a standardized intervention in ICD patients.

Workforce affiliation in primary and secondary prevention Implantable Cardioverter Defibrillator patients - a nationwide Danish study.

BACKGROUND AND AIM: There are a paucity of studies investigating workforce affiliation in connection with first-time ICD-implantation. This study explored workforce affiliation and risk markers associated with not returning to work in patients with ICDs. METHODS: Using the nationwide Danish registers, patients with a first-time ICD-implantation between 2007-2017 and of working age (30-65 years) were identified. Descriptive statistic and logistic regression models were used to describe workforce affiliation and to estimate risk markers associated with not returning to work, respectively. All analyses were stratified by indication for implantation (primary and secondary prevention). RESULTS: Of the 4,659 ICD-patients of working age, 3,300 patients (71%) were members of the workforce (employed, on sick leave or unemployed) (primary: 1428 (43%); secondary:1872 (57%)). At baseline, 842 primary and 1477 secondary prevention ICD-patients were employed. Of those employed at baseline, 81% primary and 75% secondary prevention ICD-patients returned to work within one-year, whereof more than 80% remained employed the following year. Among patients receiving sick leave benefits at baseline, 25% were employed after one-year. Risk markers of not returning to work were 'younger age' in primary prevention ICD-patients, while 'female sex', 'LVEF ≤40', 'lower income' and '≥3 comorbidities' were risk markers in secondary prevention ICD-patients. Lower educational level was a risk marker in both patient groups. CONCLUSIONS: High return-to-work proportions following ICD-implantation, with a subsequent high level of employment maintenance were found. Several significant risk markers of not returning to work were identified including 'lower educational level', that posed a risk in both patient groups.Trial registration number: Capital Region of Denmark, P-2019-051.

Atrial pacing minimization in sinus node dysfunction and risk of incident atrial fibrillation: a randomized trial.

BACKGROUND AND AIMS: High percentages of atrial pacing have been associated with an increased risk of atrial fibrillation. This study is aimed at evaluating whether atrial pacing minimization in patients with sinus node dysfunction reduces the incidence of atrial fibrillation. METHODS: In a nationwide, randomized controlled trial, 540 patients with sinus node dysfunction and an indication for first pacemaker implantation were assigned to pacing programmed to a base rate of 60 bpm and rate-adaptive pacing (DDDR-60) or pacing programmed to a base rate of 40 bpm without rate-adaptive pacing (DDD-40). Patients were followed on remote monitoring for 2 years. The primary endpoint was time to first episode of atrial fibrillation longer than 6 min. Secondary endpoints included longer episodes of atrial fibrillation, and the safety endpoint comprised a composite of syncope or presyncope. RESULTS: The median percentage of atrial pacing was 1% in patients assigned to DDD-40 and 49% in patients assigned to DDDR-60. The primary endpoint occurred in 124 patients (46%) in each treatment group (hazard ratio [HR] 0.97, 95% confidence interval [CI] 0.76-1.25, P = .83). There were no between-group differences in atrial fibrillation exceeding 6 or 24 h, persistent atrial fibrillation, or cardioversions for atrial fibrillation. The incidence of syncope or presyncope was higher in patients assigned to DDD-40 (HR 1.71, 95% CI 1.13-2.59, P = .01). CONCLUSIONS: Atrial pacing minimization in patients with sinus node dysfunction does not reduce the incidence of atrial fibrillation. Programming a base rate of 40 bpm without rate-adaptive pacing is associated with an increased risk of syncope or presyncope.

Long-term cardiovascular outcomes among immigrants and non-immigrants in cardiac resynchronization therapy: a nationwide study.

AIMS: To date, potential differences in outcomes for immigrants and non-immigrants with a cardiac resynchronization therapy (CRT), in a European setting, remain underutilized and unknown. Hence, we examined the efficacy of CRT measured by heart failure (HF)-related hospitalizations and all-cause mortality among immigrants and non-immigrants. METHODS AND RESULTS: All immigrants and non-immigrants who underwent first-time CRT implantation in Denmark (2000-2017) were identified from nationwide registries and followed for up to 5 years. Differences in HF related hospitalizations and all-cause mortality were evaluated by Cox regression analyses. From 2000 to 2017, 369 of 10 741 (3.4%) immigrants compared with 7855 of 223 509 (3.5%) non-immigrants with a HF diagnosis underwent CRT implantation. The origins of the immigrants were Europe (61.2%), Middle East (20.1%), Asia-Pacific (11.9%), Africa (3.5%), and America (3.3%). We found similar high uptake of HF guideline-directed pharmacotherapy before and after CRT and a consistent reduction in HF-related hospitalizations the year before vs. the year after CRT (61% vs. 39% for immigrants and 57% vs. 35% for non-immigrants). No overall difference in 5-year mortality among immigrants and non-immigrants was seen after CRT [24.1% and 25.8%, respectively, P-value = 0.50, hazard ratio (HR) = 1.2, 95% confidence interval (CI): 0.8-1.7]. However, immigrants of Middle Eastern origin had a higher mortality rate (HR = 2.2, 95% CI: 1.2-4.1) compared with non-immigrants. Cardiovascular causes were responsible for the majority of deaths irrespective of immigration status (56.7% and 63.9%, respectively). CONCLUSION: No overall differences in efficacy of CRT in improving outcomes between immigrants and non-immigrants were identified. Although numbers were low, a higher mortality rate among immigrants of Middle Eastern origin was identified compared with non-immigrants.

Cost-effectiveness of an antibacterial envelope for infection prevention in patients undergoing cardiac resynchronization therapy reoperations in Denmark.

AIMS: Use of an absorbable antibacterial envelope during implantation prevents cardiac implantable electronic device infections in patients with a moderate-to-high infection risk. Previous studies demonstrated that an envelope is cost-effective in high-risk patients within German, Italian, and English healthcare systems, but these analyses were based on limited data and may not be generalizable to other healthcare settings. METHODS AND RESULTS: A previously published decision-tree-based cost-effectiveness model was used to compare the costs per quality-adjusted life year (QALY) associated with adjunctive use of an antibacterial envelope for infection prevention compared to standard-of-care intravenous antibiotics. The model was adapted using data from a Danish observational two-centre cohort study that investigated infection-risk patients undergoing cardiac resynchronization therapy (CRT) reoperations with and without an antibacterial envelope (n = 1943). We assumed a cost-effectiveness threshold of €34 125/QALY gained, based on the upper threshold used by the National Institute for Health and Care Excellence (£30 000). An antibacterial envelope was associated with an incremental cost-effectiveness ratio (ICER) of €12 022 per QALY in patients undergoing CRT reoperations, thus indicating that the envelope is cost-effective when compared with standard of care. A separate analysis stratified by device type showed ICERS of €6227 (CRT defibrillator) and €29 177 (CRT pacemaker) per QALY gained. CONCLUSIONS: Cost-effectiveness ratios were favourable for patients undergoing CRT reoperations in the Danish healthcare system, and thus are in line with previous studies. Results from this study can contribute to making the technology available to Danish patients and align preventive efforts in the pacemaker and ICD area.

Severity of Brugada syndrome disease manifestation and risk of new-onset depression or anxiety: a Danish nationwide study.

AIMS: Reduced psychological health is associated with adverse patient outcomes and higher mortality. We aimed to examine if a Brugada syndrome (BrS) diagnosis and symptomatic disease presentation were associated with an increased risk of new-onset depression or anxiety and all-cause mortality. METHODS AND RESULTS: All Danish patients diagnosed with BrS (2006-2018) with no history of psychiatric disease and available for ≥6 months follow-up were identified using nationwide registries and followed for up to 5 years after diagnosis. The development of clinical depression or anxiety was evaluated using the prescription of medication and diagnosis codes. Factors associated with developing new-onset depression or anxiety were determined using a multivariate Cox proportional hazards regression model. Disease manifestation was categorized as symptomatic (aborted cardiac arrest, ventricular tachycardia, or syncope) or asymptomatic/unspecified at diagnosis. A total of 223 patients with BrS and no history of psychiatric disease were identified (72.6% male, median age at diagnosis 46 years, 45.3% symptomatic). Of these, 15.7% (35/223) developed new-onset depression or anxiety after BrS diagnosis (median follow-up 5.0 years). A greater proportion of symptomatic patients developed new-onset depression or anxiety compared with asymptomatic patients [21/101 (20.8%) and 14/122 (11.5%), respectively, P = 0.08]. Symptomatic disease presentation (HR 3.43, 1.46-8.05) and older age (lower vs. upper tertile: HR 4.41, 1.42-13.63) were significantly associated with new-onset depression or anxiety. All-cause mortality in this group of patients treated according to guidelines was low (n = 4, 1.8%); however, 3/4 developed depression or anxiety before death. CONCLUSION: Approximately, one-sixth of patients with BrS developed new-onset depression or anxiety following a diagnosis of BrS. Symptomatic BrS disease manifestation was significantly associated with new-onset depression or anxiety.

Does targeted positioning of the left ventricular pacing lead towards the latest local electrical activation in cardiac resynchronization therapy reduce the incidence of death or hospitalization for heart failure?

BACKGROUND: Cardiac resynchronization therapy (CRT) improves symptoms, health-related quality of life and long-term survival in patients with systolic heart failure (HF) and shortens QRS duration. However, up to one third of patients attain no measurable clinical benefit from CRT. An important determinant of clinical response is optimal choice in left ventricular (LV) pacing site. Observational data have shown that achieving an LV lead position at a site of late electrical activation is associated with better clinical and echocardiographic outcomes compared to standard placement, but mapping-guided LV lead placement towards the site of latest electrical activation has never been investigated in a randomized controlled trial (RCT). The purpose of this study was to evaluate the effect of targeted positioning of the LV lead towards the latest electrically activated area. We hypothesize that this strategy is superior to standard LV lead placement. METHODS: The DANISH-CRT trial is a national, double-blinded RCT (ClinicalTrials.gov NCT03280862). A total of 1,000 patients referred for a de novo CRT implantation or an upgrade to CRT from right ventricular pacing will be randomized 1:1 to receive conventional LV lead positioning preferably in a nonapical posterolateral branch of the coronary sinus (CS) (control group) or targeted positioning of the LV lead to the CS branch with the latest local electrical LV activation (intervention group). In the intervention group, late activation will be determined using electrical mapping of the CS. The primary endpoint is a composite of death and nonplanned HF hospitalization. Patients are followed for a minimum of 2 years and until 264 primary endpoints occurred. Analyses will be conducted according to the intention-to-treat principle. Enrollment for this trial began in March 2018, and per April 2023, a total of 823 patients have been included. Enrollment is expected to be complete by mid-2024. CONCLUSIONS: The DANISH-CRT trial will clarify whether mapping-guided positioning of the LV lead according to the latest local electrical activation in the CS is beneficial for patients in terms of reducing the composite endpoint of death or nonplanned hospitalization for heart failure. Results from this trial are expected to impact future guidelines on CRT. GOV IDENTIFIER: NCT03280862.

Long-term risk of cardiovascular implantable electronic device reinterventions following external cardioversion of atrial fibrillation and flutter: A nationwide cohort study.

BACKGROUND: External cardioversion (ECV) is an essential part of rhythm control of atrial fibrillation and flutter in patients with and without cardiovascular implantable electronic devices (CIEDs). Long-term follow-up data on ECV-related CIED dysfunctions are limited. OBJECTIVE: The purpose of this study was to investigate the risk of CIED reintervention following ECV in a nationwide cohort. METHODS: We identified CIED implants and surgical reinterventions from 2005 to 2021 in the Danish Pacemaker and ICD Register. We included CIED patients undergoing ECV from 2010 to 2019 from the Danish National Patient Registry. For each ECV-exposed generator, 5 matched generators without ECV were identified, and for each ECV-exposed lead, 3 matched leads were identified. The primary endpoints were generator replacement and lead reintervention. RESULTS: We compared 2582 ECV-exposed patients with 12,910 matched patients with a pacemaker (47%), implantable cardioverter-defibrillator (ICD) (29%), cardiac resynchronization therapy-pacemaker (6%), or cardiac resynchronization therapy-defibrillator (18%). During 2 years of follow-up, 210 ECV-exposed generators (8.1%) vs 670 matched generators (5.2%) underwent replacements, and 247 ECV-exposed leads (5.6%) vs 306 matched leads (2.3%) underwent reintervention. Unadjusted hazard ratios were 1.61 (95% confidence interval [CI] 1.37-1.91; P <.001) for generator replacement and 2.39 (95% CI 2.01-2.85; P <.001) for lead reintervention. One-year relative risks were 1.73 (95% CI 1.41-2.12; P <.001) for generator replacement and 2.85 (95% CI 2.32-3.51; P <.001) for lead reintervention, and 2-year relative risks were 1.39 (95% CI 1.19-1.63; P <.001) and 2.18 (95% CI 1.84-2.57; P <.001), respectively. CONCLUSION: ECV in patients with a CIED is associated with a higher risk of generator replacement and lead reintervention. The risks of reinterventions were more pronounced within the first year after cardioversion.

Use of Nonrecommended Drugs in Patients With Brugada Syndrome: A Danish Nationwide Cohort Study.

Background Patients with Brugada syndrome (BrS) are recommended to avoid drugs that may increase their risk of arrhythmic events. We examined treatment with such drugs in patients with BrS after their diagnosis. Methods and Results All Danish patients diagnosed with BrS (2006-2018) with >12 months of follow-up were identified from nationwide registries. Nonrecommended BrS drugs were grouped into drugs to "avoid" or "preferably avoid" according to http://www.brugadadrugs.org. Cox proportional hazards analyses were performed to identify factors associated with any nonrecommended BrS drug use, and logistic regression analyses were performed to examine associated risk of appropriate implantable cardioverter defibrillator therapy, mortality, and a combined end point indicating an arrhythmic event of delayed implantable cardioverter defibrillator implantation, appropriate implantable cardioverter defibrillator therapy, and mortality. During a median follow-up of 6.8 years, 93/270 (34.4%) patients with BrS (70.4% male, median age at diagnosis 46.1 years [interquartile range, 32.6-57.4]) were treated with ≥1 nonrecommended BrS drugs. No difference in any nonrecommended BrS drug use was identified comparing time before BrS diagnosis (12.6%) with each of the 5 years following BrS diagnosis (P>0.05). Factors associated with any nonrecommended BrS drug use after diagnosis were female sex (hazard ratio [HR]) 1.83 [95% CI, 1.15-2.90]), psychiatric disease (HR, 3.63 [1.89-6.99]), and prior use of any nonrecommended BrS drug (HR, 4.76 [2.45-9.25]). No significant association between any nonrecommended BrS drug use and implantable cardioverter defibrillator therapy (n=20/97, odds ratio [OR], 0.7 [0.2-2.4]), mortality (n=10/270, OR, 3.4 [0.7-19.6]), or the combined end point (n=38/270, OR, 1.7 [0.8-3.7]) was identified. Conclusions One in 3 patients with BrS were treated with a nonrecommended BrS drug after BrS diagnosis, and a BrS diagnosis did not change prescription patterns. More awareness of nonrecommended drug use among patients with BrS is needed.

Patients with an implantable cardioverter defibrillator at risk of poorer psychological health during 24 months of follow-up (results from the Danish national DEFIB-WOMEN study).

OBJECTIVE: Identify implantable cardioverter defibrillator (ICD) patients at risk of distress (i.e., depression, anxiety, and ICD concerns) and associated risk factors. METHOD: First-time ICD patients (n = 1503) from the Danish national DEFIB-WOMEN study completed questionnaires at baseline, 3, 6, 12 and 24 months. RESULTS: Of patients with low scores on distress, only 4%-7.2% experienced an increase in distress during 24 months of follow-up (FU), while 30.5%-52.5% with increased levels were likely to maintain increased levels at FU. Higher education, higher age, female sex, and good physical functioning at baseline were associated with less depression, anxiety and ICD concerns at FU. Previous psychological problems, smoking, Type D personality, NYHA class III-IV - all assessed at baseline - and shocks during FU were associated with depression, anxiety and ICD concerns. CONCLUSIONS: Generally, patients' psychological health improved, but patients with increased baseline scores were more likely to have increased scores at FU. We need to be vigilant if patients report elevated distress, particularly if they have depression at baseline, as depression seems more persistent. Given the impact of depression on health-related quality of life and prognosis, they should be screened and monitored closely.

Sex differences in the course of implantable cardioverter defibrillator concerns (Results from the Danish national DEFIB-WOMEN study).

OBJECTIVE: The implantable cardioverter defibrillator (ICD) is used to treat malignant ventricular arrhythmias. Since 33% of patients experience ICD-related concerns, we examined sex differences in ICD concerns and correlates of ICD concerns during 24 months of follow-up after implantation of an ICD. METHODS: Patients from the DEFIB-WOMEN study (n = 1515; 81.6% male patients) completed questionnaires on ICD concerns, anxiety, depression, and Type D personality at five measure points (baseline, 3-, 6-, 12- and 24-months post-implantation). RESULTS: Male patients scored on average 7.0 (6.8) points on ICD concerns at the time of implantation and female patients scored on average 10.5 (8.2) points. We found statistically significant sex differences in ICD concerns at all measurement points, with female patients scoring 2.77 points (8.7% of the maximum score of 32) higher than male patients. ICD concerns decreased in both sexes the first 6 months and then levelled out. For both sexes, ICD concerns at baseline were significantly correlated with ICD concerns at 24-months follow-up. Anxiety at baseline was correlated with ICD concerns in female patients, while depression at baseline and at least one experienced shock correlated with ICD concerns in male patients. CONCLUSION: Female patients reported more ICD concerns at all measurement points compared to male patients, but for both sexes ICD concerns decreased in the first 6 months. ICD shock, anxiety, depression, and ICD concerns at baseline were correlates of ICD concerns at 24-months follow-up.

Cardiac surgery in patients with cardiac implantable electronic devices and risk of device infections: a nationwide nested case-control study.

PURPOSE: Cardiac surgery in patients with cardiac implantable electronic devices (CIEDs) has been associated with a higher risk of infective endocarditis, but how it influences risk of CIED-specific infections is not known. Our aim was to examine risk of systemic CIED infections after cardiac surgery in patients with CIEDs. METHODS: Based on data obtained from Danish administrative registries and the Danish Pacemaker and ICD Register, we conducted a case-control study nested within a nationwide cohort of patients who underwent a de novo CIED implantation in Denmark between 1998 and 2017. We defined cases as incident systemic CIED infections resulting in device system extraction. Controls were sampled 1:100 on time, age, sex and device type using risk set sampling. Exposure was defined as coronary artery bypass graft, or cardiac heart valve replacement or repair surgery. RESULTS: From a study cohort comprising 67,621 patients, we identified 170 cases and 16,788 controls. In the minimally adjusted model, the incidence rate ratio (IRR) for systemic CIED infection was 6.4 (95% confidence interval (CI) 3.8-10.7) with cardiac surgery, and after additional confounder adjustment, 5.4 (95% CI 3.2-9.2). IRRs were higher with restriction to heart valve replacement surgery (adjusted IRR 7.5, 95% CI 4.0-16.6), and when limiting our exposure time window to one year (adjusted IRR 10.1, 95% CI 4.5-22.3). CONCLUSION: Cardiac surgery in patients with de novo CIEDs was associated with a high risk of systemic CIED infections. Highest risk was observed after heart valve replacement surgery and within the first year of surgery.

Predictors of pocket hematoma after cardiac implantable electronic device surgery: A nationwide cohort study.

Purpose: Clinically significant pocket hematoma (CSH) is a common complication to cardiac implantable electronic device (CIED) surgery. We aimed to evaluate predictors of CSH after CIED surgery. Methods: We performed a nationwide population-based prospective cohort study with systematic patient chart review of all Danish patients undergoing CIED surgery during a 12-month period. Multiple logistic regression analysis was used to estimate adjusted odds ratios (aOR) with 95% confidence intervals for association between predictors and CSH. Results: We included 5918 consecutive patients, 63% males, mean age 72.6 years. A total of 148 (2.5%) patients experienced CSH, including 10 patients (0.2%) requiring re-operation with hematoma evacuation. The risk of CSH was significantly increased in patients treated with aspirin (aOR 1.8; 1.2-2.7), aspirin and clopidogrel (aOR 3.9; 2.3-6.5), or heparin (aOR 2.1; 1.1-4.1), and in patients with INR≥2.0 (aOR 2.0; 1.2-3.2). Patients operated by low-volume operators (aOR 2.7; 1.6-4.6) or undergoing more complex CIED surgery such as cardiac resynchronization therapy (aOR 2.0; 1.1-3.5) or dual-chamber defibrillator (aOR 2.1; 1.2-3.8) also had significantly increased CSH risk. Conclusion: In a large nationwide cohort of consecutive patients undergoing CIED surgery, the risk of CSH was 2.5%, with 0.2% necessitating evacuation. CSH risk was increased both in patients receiving aspirin, dual antiplatelet therapy or continued vitamin K-antagonist therapy. Dual antiplatelet therapy had the highest risk (aOR) of CSH. Both low operator volume and more complex CIED surgery were independently associated with higher CSH risk. These data should be considered when planning CIED surgery.

Risk factors for cardiac implantable electronic device infections: a nationwide Danish study.

AIMS: Cardiac implantable electronic device (CIED) infection is a severe complication to modern management of cardiac arrhythmias. The CIED type and the type of surgery are recognized as risk factors for CIED infections, but knowledge of patient-related risk factors is scarce. This study aimed to identify lifelong patient-related risk factors for CIED infections. METHODS AND RESULTS: Consecutive Danish patients undergoing a CIED implantation or reoperation between January 1996 and April 2018 were included. The cohort consisted of 84 429 patients undergoing 108 494 CIED surgeries with a combined follow-up of 458 257 CIED-years. A total of 1556 CIED explantations were classified as either pocket (n = 1022) or systemic CIED infection (n = 534). Data were cross-linked with records from the Danish National Patient Registry and the Danish National Prescription Registry. Using multiple-record and multiple-event per subject proportional hazard analysis, specific patient-related risk factors were identified but with several variations amongst the subtypes of CIED infection. CIED reoperations were associated with the highest risk of pocket CIED infection but also CIED type, young age, and prior valvular surgery [hazard ratio (HR): 1.62, 95% confidence interval (CI): 1.29-2.04]. Severe renal insufficiency/dialysis (HR: 2.40, 95% CI: 1.65-3.49), dermatitis (HR: 2.80, 95% CI: 1.92-4.05), and prior valvular surgery (HR: 2.09, 95% CI: 1.59-2.75) were associated with the highest risk of systemic CIED infections. Congestive heart failure, ischaemic heart disease, malignancy, chronic obstructive pulmonary disease, and temporary pacing were not significant at multivariate analysis. CONCLUSION: Specific comorbidities and surgical procedures were associated with a higher risk of CIED infections but with variations amongst pocket and systemic CIED infection. Pocket CIED infections were associated with CIED reoperations, young age and more complex type of CIED, whereas systemic CIED infections were associated with risk factors predisposing to bacteraemia.

Lead complications after cardiac surgery in patients with cardiac implantable electronic devices.

OBJECTIVES: Manipulation of the heart during cardiac surgery in patients with cardiac implantable electronic devices (CIEDs) may result in lead damage or displacement, but whether cardiac surgery truly infers an excess risk of lead failure is not known. The objective of this study was to examine the risk of lead complications after cardiac surgery in patients with CIEDs. METHODS: We conducted a nationwide nested case-control study. The source population comprised all Danish patients ≥18 of age who underwent a de novo CIED implantation during 1998-2017. For inclusion, patients had to be alive and event free 6 months after implantation. Cases were matched 1:30 to controls on time, age, sex, and device type using risk set sampling. We used conditional logistic regression to estimate incidence rate ratios (IRRs) for the association between cardiac surgery and lead-related reoperation. RESULTS: Our final population consisted of 67 621 patients. We identified 1437 (2.1%) incident cases of lead-related reoperations and 42 698 controls. Risk of lead complications was highest within 6 months of cardiac surgery [IRR 9.7, 95% confidence interval (CI) 6.3-14.8, adjusted IRR 9.6, 95% CI 6.2-14.7], and at 1 year, the relative risk of lead-related reoperation was close to unity (adjusted IRR 1.2, 95% CI 0.8-1.7). CONCLUSIONS: Cardiac surgery was associated with a considerable risk of lead complications in patients with de novo CIEDs.

Troubleshooting the difficult left ventricular lead placement in cardiac resynchronization therapy: current status and future perspectives.

INTRODUCTION: Cardiac resynchronization therapy (CRT) is an important option in modern cardiac implantable electronic device (CIED) treatment. Techniques for left ventricular (LV) lead placement in the coronary sinus and its tributaries are neither well described nor studied systematically, despite attention regarding where to place the LV lead. AREAS COVERED: This review presents specialized tools and techniques to overcome some of the most common problems encountered in LV lead placement in CRT. These tools and techniques are termed Interventional CRT (I-CRT), as they share technology with other interventional procedures. The main principle in I-CRT, compared to the traditional over-the-wire technique, is to add better support for delivery of the LV lead through dedicated inner catheters that also allows more flexibility with the use of more guidewires and better imaging with direct venography in the target vein. EXPERT OPINION: Even though CRT is an established therapeutic option, there are still many challenges in the implementation of the therapy. The cornerstone should be an ease of delivering the CRT and specifically implantation of the LV lead. Therefore, knowledge of the principles in I-CRT is necessary, as I-CRT could make implantation simpler in general and easier to reach the optimal LV pacing site.

Diagnostic Yield of Genetic Testing in Young Patients With Atrioventricular Block of Unknown Cause.

Background The cause of atrioventricular block (AVB) remains unknown in approximately half of young patients with the diagnosis. Although variants in several genes associated with cardiac conduction diseases have been identified, the contribution of genetic variants in younger patients with AVB is unknown. Methods and Results Using the Danish Pacemaker and Implantable Cardioverter Defibrillator (ICD) Registry, we identified all patients younger than 50 years receiving a pacemaker because of AVB in Denmark in the period from January 1, 1996 to December 31, 2015. From medical records, we identified patients with unknown cause of AVB at time of pacemaker implantation. These patients were invited to a genetic screening using a panel of 102 genes associated with inherited cardiac diseases. We identified 471 living patients with AVB of unknown cause, of whom 226 (48%) accepted participation. Median age at the time of pacemaker implantation was 39 years (interquartile range, 32-45 years), and 123 (54%) were men. We found pathogenic or likely pathogenic variants in genes associated with or possibly associated with AVB in 12 patients (5%). Most variants were found in the LMNA gene (n=5). LMNA variant carriers all had a family history of either AVB and/or sudden cardiac death. Conclusions In young patients with AVB of unknown cause, we found a possible genetic cause in 1 out of 20 participating patients. Variants in the LMNA gene were most common and associated with a family history of AVB and/or sudden cardiac death, suggesting that genetic testing should be a part of the diagnostic workup in these patients to stratify risk and screen family members.

Rate of permanent cardiac implantable electronic device infections after active fixation temporary transvenous pacing: A nationwide Danish cohort study.

BACKGROUND: Temporary transvenous pacing (TP) has been associated with an increased risk of cardiac implantable electronic device (CIED) infections, but there is little data to document this in contemporary populations. OBJECTIVE: To investigate the impact of active fixation TP on rate of CIED infections in a nationwide cohort of Danish patients. METHODS: We identified all patients who underwent a first-time CIED implantation between 2009 and 2017. Patients were categorized according to TP status at implantation and followed for 1 year. The primary outcome was local or systemic CIED infection resulting in device system removal. The secondary outcomes were systemic CIED infections and hospitalization for infective endocarditis (IE). RESULTS: We included a total of 40,601 CIED patients. A total of 2952 were treated with active fixation TP. The primary outcome was met in 246 patients. Risk of CIED infection at 1 year was 0.61% for patients not treated with TP and 0.65% for patients who were, HR of 1.28 (95% CI 0.80-2.05) and adjusted HR 0.85 (95% CI 0.51-1.42). More systemic CIED infections and IE hospitalizations occurred in TP patients; however, these differences did not persist after confounder adjustment. Cumulative mortality at 1 year was 16.8% in patients with TP vs 8.4% in patients without. CONCLUSION: Active fixation TP was not associated with a higher rate of CIED infections. Patients treated with TP had higher mortality, more systemic CIED infections, and more IE hospitalizations within first year of implantation. Most was attributable to an accumulation of risk factors for infection among TP patients.