Risk factors associated with clinically relevant pericardial effusion after primary cardiac implantable electronic device implantation.

INTRODUCTION: Pericardial effusion, a known complication to implantation of cardiac implantable electronic devices (CIED), may cause life-threatening cardiac tamponade. Limited knowledge is available about risk factors for clinically relevant procedural pericardial effusion. The aim is to identify the patient- and procedure-related risk factors associated with clinically relevant procedural pericardial effusion. METHOD: A nationwide observational cohort study based on data on 55 121 patients from the Danish Pacemaker Register between 2000 and 2018. We defined a clinically relevant procedural pericardial effusion related to the implantation if it occurred within 90 days after the primary CIED-procedure. Prespecified risk factors were analysed by multivariable logistic regression models to estimate the association with pericardial effusion. RESULTS: There were 115 (0.21%) patients diagnosed with clinically relevant procedural pericardial effusion, with a median age of 75 years and 38.3% were females. Of these, 80.9% lead to a subsequent pericardiocentesis procedure. In adjusted logistic regression analysis, an increased risk of clinically relevant pericardial effusion was associated with female sex (OR:1.49 [95%CI: 1.03-2.16]), heart failure (OR:1.54 [95%CI: 1.06-2.23]), previous cardiac surgery (OR:1.63 [95%CI: 1.05-2.55]), CRT-device (OR:2.05 [95%CI: 1.23-3.41]), tertiary-centres (OR:1.8 [95%CI: 1.18-2.73]), increased procedural volume per year (>1000) (OR:1.85 [95%CI: 1.03-3.30]), indication of device-implantation (atrioventricular block) (OR:2.37 [95CI: 1.45-3.87]), and increasing number of leads implanted (two leads (OR:2.39 [95%CI: 1.43-4.00]), three leads (OR:4.77 [95%CI: 2.50-9.10])). CONCLUSION: Clinically relevant procedural pericardial effusion is a rare complication after CIED-implantation in Denmark. This study reveals important patient- and procedure-related risk factors associated with clinically relevant procedural pericardial effusion.

Association between QRS shortening and mortality after cardiac resynchronization therapy: Results from the DANISH study.

BACKGROUND: Changes in QRS duration (∆QRS) are often used in the clinical setting to evaluate the effect of cardiac resynchronization therapy (CRT), although an association between ∆QRS and outcomes is not firmly established. We aimed to assess the association between mortality and ∆QRS after CRT in patients from the DANISH (Danish Study to Assess the Efficacy of ICDs in Patients with Non-Ischemic Systolic Heart Failure on Mortality) study. METHODS: We included all patients from DANISH who received a CRT device and had available QRS duration data before and after implantation. Cox proportional hazards models were used to assess associations between ∆QRS (post-CRT QRS minus pre-CRT QRS) and mortality. RESULTS: Complete data were available in 572 patients. Median baseline QRS duration was 160 ms (IQR [146;180]). Post-CRT QRS was recorded a median of 48 days (IQR [33;86]) after implantation, and the median ∆QRS was -14 ms (IQR [-38;-3]). During a median follow-up of 4.1 years (IQR [2.5;5.8]), 106 patients died. In crude Cox regression, all-cause mortality was reduced by 6% per 10 ms shortening of QRS (HR 0.94; CI: 0.88-1.00, p = 0.04). The effect did not remain significant after multivariable adjustment (HR 1.01, CI: 0.93-1.10, p = 0.77). Further, no association was found between ∆QRS and improvement of New York Heart Association functional class at 6 months (OR 1.03, CI: 0.96-1.10, p = 0.42). CONCLUSION: In a large cohort of patients with non-ischemic cardiomyopathy, reduction of QRS duration after CRT was not associated with changes in mortality during long-term follow-up.

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.

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.

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.

Type 2 diabetes mellitus and higher rate of complete atrioventricular block: a Danish Nationwide Registry.

AIMS: The present study aimed to determine the association between Type 2 diabetes mellitus (T2DM) and third-degree (complete) atrioventricular block. METHODS AND RESULTS: This nationwide nested case-control study included patients older than 18 years, diagnosed with third-degree atrioventricular block between 1 July 1995 and 31 December 2018. Data on medication, comorbidity, and outcomes were collected from Danish registries. Five controls, from the risk set of each case of third-degree atrioventricular block, were matched on age and sex to fit a Cox regression model with time-dependent exposure and time-dependent covariates. Subgroup analysis was conducted with Cox regression models for each subgroup. We located 25 995 cases with third-degree atrioventricular block that were matched with 130 004 controls. The mean age was 76 years and 62% were male. Cases had more T2DM (21% vs. 11%), hypertension (69% vs. 50%), atrial fibrillation (25% vs. 10%), heart failure (20% vs. 6.3%), and myocardial infarction (19% vs. 9.2%), compared with the control group. In Cox regression analysis, adjusting for comorbidities and atrioventricular nodal blocking agents, T2DM was significantly associated with third-degree atrioventricular block (hazard ratio: 1.63, 95% confidence interval: 1.57-1.69). The association remained in several subgroup analyses of diseases also suspected to be associated with third-degree atrioventricular block. There was a significant interaction with comorbidities of interest including hypertension, atrial fibrillation, heart failure, and myocardial infarction. CONCLUSION: In this nationwide study, T2DM was associated with a higher rate of third-degree atrioventricular block compared with matched controls. The association remained independent of atrioventricular nodal blocking agents and other comorbidities known to be associated with third-degree atrioventricular block.

Myocardial fibrosis and ventricular ectopy in patients with non-ischemic systolic heart failure: results from the DANISH trial.

Patients with non-ischemic systolic heart failure (HF) have increased risk of sudden cardiovascular death (SCD). The initiation and substrate for ventricular arrhythmias remains poorly understood. Our purpose was to describe the relationship between cardiac magnetic resonance (CMR) late gadolinium enhancement (LGE) and Holter recorded ventricular arrhythmic activity. Patients from the DANISH trial underwent a Holter-recording and a CMR-scan. The presence of non-sustained ventricular tachycardia (NSVT) and premature ventricular contractions (PVC) were examined in relation to presence and amount of LGE. Outcome measures were all-cause mortality and SCD. Overall, 180 patients were included. LGE was present in 86 (47%). NSVT occurred in 72 (40%), not different according to LGE status (p = 0.65). The amount of LGE was not correlated to the occurrence of NSVT (p = 0.40). The occurrence of couplet PVCs (p = 0.997), frequent PVCs (p = 0.12), PVCs in bigemini (p = 0.29), in trigemini (p = 0.26), or in quadrimini (p = 0.35) did not differ according to LGE status. LGE was significantly associated with risk of all-cause mortality (HR 2.14; 95% CI 1.05-4.37, p = 0.04). NSVT did not increase risk of all-cause mortality in either patients with LGE (HR 1.00; 95% CI 0.46-2.16, p = 0.996) or without LGE (HR 1.37; 95% CI 0.46-4.08, p = 0.57). There was no interaction between LGE and NSVT for the risk of all-cause mortality (p = 0.62). In patients with non-ischemic systolic HF there was no relationship between the presence of LGE and NSVT or any other Holter recorded ventricular tachyarrhythmia. LGE was associated with increased risk of mortality, independent of the presence of NSVT.

Device-related complications in subcutaneous versus transvenous ICD: a secondary analysis of the PRAETORIAN trial.

BACKGROUND: The subcutaneous implantable cardioverter-defibrillator (S-ICD) is developed to overcome lead-related complications and systemic infections, inherent to transvenous ICD (TV-ICD) therapy. The PRAETORIAN trial demonstrated that the S-ICD is non-inferior to the TV-ICD with regard to the combined primary endpoint of inappropriate shocks and complications. This prespecified secondary analysis evaluates all complications in the PRAETORIAN trial. METHODS AND RESULTS: The PRAETORIAN trial is an international, multicentre, randomized trial in which 849 patients with an indication for ICD therapy were randomized to receive an S- ICD (N = 426) or TV-ICD (N = 423) and followed for a median of 49 months. Endpoints were device-related complications, lead-related complications, systemic infections, and the need for invasive interventions. Thirty-six device-related complications occurred in 31 patients in the S-ICD group of which bleedings were the most frequent. In the TV-ICD group, 49 complications occurred in 44 patients of which lead dysfunction was most frequent (HR: 0.69; P = 0.11). In both groups, half of all complications were within 30 days after implantation. Lead-related complications and systemic infections occurred significantly less in the S-ICD group compared with the TV-ICD group (P < 0.001, P = 0.03, respectively). Significantly more complications required invasive interventions in the TV-ICD group compared with the S-ICD group (8.3% vs. 4.3%, HR: 0.59; P = 0.047). CONCLUSION: This secondary analysis shows that lead-related complications and systemic infections are more prevalent in the TV-ICD group compared with the S-ICD group. In addition, complications in the TV-ICD group were more severe as they required significantly more invasive interventions. This data contributes to shared decision-making in clinical practice.

Periodic Repolarization Dynamics Identifies ICD Responders in Nonischemic Cardiomyopathy: A DANISH Substudy.

BACKGROUND: Identification of patients with nonischemic cardiomyopathy who may benefit from prophylactic implantation of a cardioverter-defibrillator. We hypothesized that periodic repolarization dynamics (PRD), a marker of repolarization instability associated with sympathetic activity, could be used to identify patients who will benefit from prophylactic implantable cardioverter defibrillator (ICD) implantation. METHODS: We performed a post hoc analysis of DANISH (Danish ICD Study in Patients With Dilated Cardiomyopathy), in which patients with nonischemic cardiomyopathy, left ventricular ejection fraction (LVEF) ≤35%, and elevated NT-proBNP (N-terminal probrain natriuretic peptides) were randomized to ICD implantation or control group. Patients were included in the PRD substudy if they had a 24-hour Holter monitor recording at baseline with technically acceptable ECG signals during the night hours (00:00-06:00). PRD was assessed using wavelet analysis according to previously validated methods. The primary end point was all-cause mortality. Cox regression models were adjusted for age, sex, NT-proBNP, estimated glomerular filtration rate, LVEF, atrial fibrillation, ventricular pacing, diabetes, cardiac resynchronization therapy, and mean heart rate. We proposed PRD ≥10 deg2 as an exploratory cut-off value for ICD implantation. RESULTS: A total of 748 of the 1116 patients in DANISH qualified for the PRD substudy. During a mean follow-up period of 5.1±2.0 years, 82 of 385 patients died in the ICD group and 85 of 363 patients died in the control group (P=0.40). In Cox regression analysis, PRD was independently associated with mortality (hazard ratio [HR], 1.28 [95% CI, 1.09-1.50] per SD increase; P=0.003). PRD was significantly associated with mortality in the control group (HR, 1.51 [95% CI, 1.25-1.81]; P<0.001) but not in the ICD group (HR, 1.04 [95% CI, 0.83-1.54]; P=0.71). There was a significant interaction between PRD and the effect of ICD implantation on mortality (P=0.008), with patients with higher PRD having greater benefit in terms of mortality reduction. ICD implantation was associated with an absolute mortality reduction of 17.5% in the 280 patients with PRD ≥10 deg2 (HR, 0.54 [95% CI, 0.34-0.84]; P=0.006; number needed to treat=6), but not in the 468 patients with PRD <10 deg2 (HR, 1.17 [95% CI, 0.77-1.78]; P=0.46; P for interaction=0.01). CONCLUSIONS: Increased PRD identified patients with nonischemic cardiomyopathy in whom prophylactic ICD implantation led to significant mortality reduction.

Efficacy and Safety of Appropriate Shocks and Antitachycardia Pacing in Transvenous and Subcutaneous Implantable Defibrillators: Analysis of All Appropriate Therapy in the PRAETORIAN Trial.

BACKGROUND: The PRAETORIAN trial (A Prospective, Randomized Comparison of Subcutaneous and Transvenous Implantable Cardioverter Defibrillator Therapy) showed noninferiority of subcutaneous implantable cardioverter defibrillator (S-ICD) compared with transvenous implantable cardioverter defibrillator (TV-ICD) with regard to inappropriate shocks and complications. In contrast to TV-ICD, S-ICD cannot provide antitachycardia pacing for monomorphic ventricular tachycardia. This prespecified secondary analysis evaluates appropriate therapy and whether antitachycardia pacing reduces the number of appropriate shocks. METHODS: The PRAETORIAN trial was an international, investigator-initiated randomized trial that included patients with an indication for implantable cardioverter defibrillator (ICD) therapy. Patients with previous ventricular tachycardia <170 bpm or refractory recurrent monomorphic ventricular tachycardia were excluded. In 39 centers, 849 patients were randomized to receive an S-ICD (n=426) or TV-ICD (n=423) and were followed for a median of 49.1 months. ICD programming was mandated by protocol. Appropriate ICD therapy was defined as therapy for ventricular arrhythmias. Arrhythmias were classified as discrete episodes and storm episodes (≥3 episodes within 24 hours). Analyses were performed in the modified intention-to-treat population. RESULTS: In the S-ICD group, 86 of 426 patients received appropriate therapy, versus 78 of 423 patients in the TV-ICD group, during a median follow-up of 52 months (48-month Kaplan-Meier estimates 19.4% and 17.5%; P=0.45). In the S-ICD group, 83 patients received at least 1 shock, versus 57 patients in the TV-ICD group (48-month Kaplan-Meier estimates 19.2% and 11.5%; P=0.02). Patients in the S-ICD group had a total of 254 shocks, compared with 228 shocks in the TV-ICD group (P=0.68). First shock efficacy was 93.8% in the S-ICD group and 91.6% in the TV-ICD group (P=0.40). The first antitachycardia pacing attempt successfully terminated 46% of all monomorphic ventricular tachycardias, but accelerated the arrhythmia in 9.4%. Ten patients with S-ICD experienced 13 electrical storms, versus 18 patients with TV-ICD with 19 electrical storms. Patients with appropriate therapy had an almost 2-fold increased relative risk of electrical storms in the TV-ICD group compared with the S-ICD group (P=0.05). CONCLUSIONS: In this trial, no difference was observed in shock efficacy of S-ICD compared with TV-ICD. Although patients in the S-ICD group were more likely to receive an ICD shock, the total number of appropriate shocks was not different between the 2 groups. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01296022.

Clinical performance of implantable cardioverter-defibrillator lead monitoring diagnostics.

BACKGROUND: Implantable cardioverter-defibrillator (ICD) lead monitoring diagnostic alerts facilitate the diagnosis of structural lead failure. OBJECTIVE: The purpose of this study was to prospectively study the performance of Medtronic ICD lead monitoring alerts. METHODS: A prespecified ancillary substudy, World-Wide Randomized Antibiotic Envelope Infection Prevention Trial, was conducted in patients with an ICD with all available alerts enabled. The investigators reported possible lead system events (LSEs), with or without an alert. An independent committee reviewed all data and classified events as lead failure, other LSE, or nonlead system events (NLEs). RESULTS: In 4942 patients who were followed for 19.4 ± 8.7 months, there were 124 alerts (65 LSEs, 59 NLEs) and 19 LSEs without an alert. Lead monitoring alerts had 100% sensitivity for the 48 adjudicated lead failures (95% confidence interval 92.6%-100%) and for 10 events adjudicated as either lead failure or connection issue. The positive predictive value of alerts for lead failure was 38.7% (48 of 124). For 34 pace-sense lead failures, an alert that incorporated oversensing was more sensitive than the pacing impedance threshold alert (33 patients [97.1%] vs 9 patients [26.5%]; P < .0001). However, the sensitivity was only 13.6% for lead dislodgments or perforations. Inappropriate shocks occurred in 2 patients with pace-sense lead failure (5.9%). No patient had unnecessary lead replacement for any of the NLEs. CONCLUSION: In this first real-world prospective study, lead monitoring alerts had 100% sensitivity for identifying lead failures. Although their positive predictive value was modest, no false-positive alerts resulted in an unnecessary lead replacement. For the diagnosis of pace-sense lead failure, an alert for oversensing was more sensitive than a pacing impedance threshold alert. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02277990.

Cause-specific death and risk factors of 1-year mortality after implantable cardioverter-defibrillator implantation: a nationwide study.

AIMS: Current treatment guidelines recommend implantable cardioverter-defibrillators (ICDs) in eligible patients with an estimated survival beyond 1 year. There is still an unmet need to identify patients who are unlikely to benefit from an ICD. We determined cause-specific 1-year mortality after ICD implantation and identified associated risk factors. METHODS AND RESULTS: Using Danish nationwide registries (2000-2017), we identified 14 516 patients undergoing first-time ICD implantation for primary or secondary prevention. Risk factors associated with 1-year mortality were evaluated using multivariable logistic regression. The median age was 66 years, 81.3% were male, and 50.3% received an ICD for secondary prevention. The 1-year mortality rate was 4.8% (694/14 516). ICD recipients who died within 1 year were older and more comorbid compared to those who survived (72 vs. 66 years, P < 0.001). Risk factors associated with increased 1-year mortality included dialysis [odds ratio (OR): 3.26, confidence interval (CI): 2.37-4.49], chronic renal disease (OR: 2.14, CI: 1.66-2.76), cancer (OR: 1.51, CI: 1.15-1.99), age 70-79 years (OR: 1.65, CI: 1.36-2.01), and age ≥80 years (OR: 2.84, CI: 2.15-3.77). The 1-year mortality rates for the specific risk factors were: dialysis (13.8%), chronic renal disease (13.1%), cancer (8.5%), age 70-79 years (6.9%), and age ≥80 years (11.0%). Overall, the most common causes of mortality were related to cardiovascular diseases (62.5%), cancer (10.1%), and endocrine disorders (5.0%). However, the most common cause of death among patients with cancer was cancer-related (45.7%). CONCLUSION: Among ICD recipients, mortality rates were low and could be indicative of relevant patient selection. Important risk factors of increased 1-year mortality included dialysis, chronic renal disease, cancer, and advanced age.

Clinician Preimplementation Perspectives of a Decision-Support Tool for the Prediction of Cardiac Arrhythmia Based on Machine Learning: Near-Live Feasibility and Qualitative Study.

BACKGROUND: Artificial intelligence (AI), such as machine learning (ML), shows great promise for improving clinical decision-making in cardiac diseases by outperforming statistical-based models. However, few AI-based tools have been implemented in cardiology clinics because of the sociotechnical challenges during transitioning from algorithm development to real-world implementation. OBJECTIVE: This study explored how an ML-based tool for predicting ventricular tachycardia and ventricular fibrillation (VT/VF) could support clinical decision-making in the remote monitoring of patients with an implantable cardioverter defibrillator (ICD). METHODS: Seven experienced electrophysiologists participated in a near-live feasibility and qualitative study, which included walkthroughs of 5 blinded retrospective patient cases, use of the prediction tool, and questionnaires and interview questions. All sessions were video recorded, and sessions evaluating the prediction tool were transcribed verbatim. Data were analyzed through an inductive qualitative approach based on grounded theory. RESULTS: The prediction tool was found to have potential for supporting decision-making in ICD remote monitoring by providing reassurance, increasing confidence, acting as a second opinion, reducing information search time, and enabling delegation of decisions to nurses and technicians. However, the prediction tool did not lead to changes in clinical action and was found less useful in cases where the quality of data was poor or when VT/VF predictions were found to be irrelevant for evaluating the patient. CONCLUSIONS: When transitioning from AI development to testing its feasibility for clinical implementation, we need to consider the following: expectations must be aligned with the intended use of AI; trust in the prediction tool is likely to emerge from real-world use; and AI accuracy is relational and dependent on available information and local workflows. Addressing the sociotechnical gap between the development and implementation of clinical decision-support tools based on ML in cardiac care is essential for succeeding with adoption. It is suggested to include clinical end-users, clinical contexts, and workflows throughout the overall iterative approach to design, development, and implementation.

New onset anxiety and depression in patients with an implantable cardioverter defibrillator during 24 months of follow-up (data from the national DEFIB-WOMEN study).

OBJECTIVE: To examine the cumulative incidence of and covariates' association with new onset anxiety and depression in implantable cardioverter defibrillator (ICD) patients during 24 months of follow-up in patients without depression and anxiety at implant. METHODS: Patients (n = 1040; 155 (14.9%) women; mean age: 64.2 ± 10.6) with a first-time ICD enrolled in the national, multi-center prospective observational DEFIB-WOMEN study comprised the study cohort. We obtained information on demographic and clinical data from the Danish Pacemaker and ICD Register. RESULTS: During 24 months of follow-up, 138 (14.5%) patients developed new onset anxiety and 109 (11.3%) new onset depression. Age ≥ 60 [HR:0.60;95%CI:0.40-0.90] and an anxiety score between 3 and 4 [HR:2.85; 95%CI:1.71-4.75] and 5-7 [HR:5.97; 95%CI:3.77-9.45] on the Hospital Anxiety and Depression Scale (HADS) were associated with different hazards of new onset anxiety during follow-up. Age ≥ 60 [HR:0.62;95%CI:0.42-0.93] and a HADS depression score between 3 and 4 [HR:2.99;95%CI:1.80-4.95] and 5-7 [HR:6.45; 95%CI:4.12-10.10] were associated with different hazards of new onset depression. CONCLUSION: During 24 months of follow-up, respectively 14.5% and 11.3% of patients developed new onset anxiety and depression, suggesting that screening patients at several timepoints, and in particular those with even minimally elevated HADS scores at baseline, may be warranted to identify patients at risk for poor health outcomes.

Early ICD implantation in cardiac arrest survivors with acute coronary syndrome - predictors of implantation, ICD-therapy and long-term survival.

Objectives. Implantable cardioverter defibrillator (ICD) implantation in patients resuscitated from out-of-hospital cardiac arrest (OHCA) due to acute myocardial infarction (AMI) is controversial. Design. Consecutive OHCA-survivors due to AMI from two Danish tertiary heart centers from 2007 to 2011 were included. Predictors of ICD-implantation, ICD-therapy and long-term survival (5 years) were investigated. Patients with and without ICD-implantation during the index hospital admission were included (later described as early ICD-implantation). Patients with an ICD after hospital discharge were censored from further analyses at time of implantation. Results. We identified 1,457 consecutive OHCA-patients, and 292 (20%) of the cohort met the inclusion criteria. An ICD was implanted during hospital admission in 78 patients (27%). STEMI and successful revascularization were inversely and independently associated with ICD-implantation (ORSTEMI = 0.37, 95% CI: 0.14-0.94, ORrevasc = 0.11, 0.03-0.36) whereas age, sex, LVEF <35%, comorbidity burden or shockable first OHCA-rhythm were not associated with ICD-implantation. Appropriate ICD-shock therapy during the follow-up period was noted in 15% of patients (n = 12). Five-year mortality-rate was significantly lower in ICD-patients (18% vs. 28%, plogrank = 0.02), which was persistent after adjustment for prognostic factors (HR = 0.44 (95% CI: 0.23-0.88)). This association was no longer found when using first event (death or appropriate shock whatever came first) as outcome variable (plogrank = 0.9). Conclusions. Mortality after OHCA due to AMI was significantly lower in patients with early ICD-implantation after adjustment for prognostic factors. When using appropriate shock and death as events, ICD-patients had similar outcome as patients without an ICD, which may suggest a survival benefit due to appropriate device therapy.

Temporal Incidence of Appropriate and Inappropriate Therapy and Mortality in Secondary Prevention ICD Patients by Cardiac Diagnosis.

OBJECTIVES: This study sought to estimate the temporal development in rates and incidences of appropriate and inappropriate implantable cardioverter-defibrillator (ICD) therapy and shocks by cardiac diagnosis in a real-world population of patients with secondary prevention ICDs. BACKGROUND: Data on cardiac diagnoses and temporal development of ICD therapies in patients with secondary prevention ICDs are limited. METHODS: Patients (N = 4,587) with a secondary prevention ICD were identified from the Danish Pacemaker and ICD Register (January 1, 2007, to December 31, 2016) and linked to nationwide administrative registers. The outcome of appropriate and inappropriate ICD therapy and all-cause mortality were analyzed by annual event rates, cumulative incidence plots, and Cox regression models. RESULTS: During a mean follow-up of 3.6 ± 2.4 years, 1,362 patients (30%) experienced appropriate ICD therapy (16.8% shocks), and 350 patients (7.6%) experienced inappropriate ICD therapy (4.6% shocks). From 2007 to 2016, there was a significant temporal reduction in both appropriate and inappropriate ICD therapy from 28.2 (95% confidence interval [CI]: 21.6 to 37.0) to 7.9 (95% CI: 6.8 to 9.1) and 10.0 (95% CI: 6.4 to 15.5) to 1.0 (95% CI: 0.7 to 1.5) per 100 person-years (p for trends <0.001). Multivariate Cox regression analyses showed that arrhythmogenic right ventricular cardiomyopathy was associated with the highest probability of appropriate ICD therapy (hazard ratio: 2.45; 95% CI: 1.77 to 3.39; p < 0.0001), whereas patients with hypertrophic cardiomyopathy had the lowest probability (hazard ratio: 0.62; 95% CI: 0.42 to 0.93; p = 0.0196) when compared to patients with ischemic heart disease. CONCLUSIONS: In this nationwide real-life cohort of patients with secondary prevention ICDs, we observed a significant temporal decline in delivered appropriate and inappropriate shocks and ICD therapies in the last decade. A large proportion of patients still experienced ICD therapy but with significant differences by cardiac diagnosis.

Prevalence and prognostic association of ventricular arrhythmia in non-ischaemic heart failure patients: results from the DANISH trial.

AIMS: Improved risk stratification to identify non-ischaemic heart failure patients who will benefit from primary prophylactic implantable cardioverter-defibrillator (ICD) is needed. We examined the potential of ventricular arrhythmia to identify patients who could benefit from an ICD. METHODS AND RESULTS: A total of 850 non-ischaemic systolic heart failure patients with left ventricle ≤35% and elevated N-terminal pro-brain natriuretic peptides had a 24-h Holter monitor recording performed. We examined present non-sustained ventricular tachycardia (NSVT), defined as ≥3 consecutive premature ventricular contractions (PVCs) with a rate of ≥100/min, and number of PVCs per hour stratified into low (<30) and high burden (≥30) groups. Outcome measures were overall mortality, sudden cardiac death (SCD), and cardiovascular death (CVD). In total, 193 patients died, 49 from SCD and 125 from CVD. Non-sustained ventricular tachycardia (365 patients) was significantly associated with increased all-cause mortality [hazard ratio (HR) 1.47; 95% confidence interval (CI) 1.07-2.03; P = 0.02] and to CVD (HR 1.89; CI 1.25-2.87; P = 0.003). High burden PVC (352 patients) was associated with increased all-cause mortality (HR1.38; CI 1.00-1.90; P = 0.046) and with CVD (HR 1.78; CI 1.19-2.66; P = 0.005). There was no statistically significant association with SCD for neither NSVT nor PVC. In interaction analyses, neither NSVT (P = 0.56) nor high burden of PVC (P = 0.97) was associated with survival benefit from ICD implantation. CONCLUSION: Ventricular arrhythmia in non-ischaemic heart failure patients was associated with a worse prognosis but could not be used to stratify patients to ICD implantation.

Atrial fibrillation is a marker of increased mortality risk in nonischemic heart failure-Results from the DANISH trial.

BACKGROUND: Atrial fibrillation (AF) in heart failure (HF) patients has been associated with a worse outcome. Similarly, excessive supraventricular ectopic activity (ESVEA) has been linked to development of AF, stroke, and death. This study aimed to investigate AF and ESVEA's association with outcomes and effect of prophylactic implantable cardioverter defibrillator (ICD) implantation in nonischemic HF patients. METHODS: A total of 850 patients with nonischemic HF, left ventricle ejection fraction ≤35%, and elevated N-terminal pro-brain natriuretic peptides underwent 24 hours Holter recording. The presence of AF (≥30 seconds) and ESVEA (≥30 supraventricular ectopic complexes (SVEC) per hour or run of SVEC ≥20 beats) were registered. Outcomes were all-cause mortality, cardiovascular death (CVD), and sudden cardiac death (SCD). RESULTS: AF was identified in 188 patients (22%) and ESVEA in 84 patients (10%). After 4 years and 11 months of follow-up, a total of 193 patients (23%) had died. AF was associated with all-cause mortality (hazard ratio [HR] 1.44; confidence interval [CI] 1.04-1.99; P = .03) and CVD (HR 1.59; CI 1.07-2.36; P = .02). ESVEA was associated with all-cause mortality (HR 1.73; CI 1.16-2.57; P = .0073) and CVD (HR 1.76; CI 1.06-2.92; P = .03). Neither AF nor ESVEA was associated with SCD. ICD implantation was not associated with an improved prognosis for neither AF (P value for interaction = .17), nor ESVEA (P value for interaction = .68). CONCLUSIONS: Both AF and ESVEA were associated with worsened prognosis in nonischemic HF. However, ICD implantation was not associated with an improved prognosis for either group.