Risk and Subtypes of Stroke Following New-Onset Postoperative Atrial Fibrillation in Coronary Bypass Surgery: A Population-Based Cohort Study

Background New-onset postoperative atrial fibrillation (POAF) develops in approximately one-third of patients undergoing cardiac surgery and is associated with a higher incidence of ischemic stroke and increased mortality. However, it remains unknown to what extent ischemic stroke events in patients with POAF are cardioembolic and whether anticoagulant therapy is indicated. We investigated the long-term risk and pathogenesis of postoperative stroke in patients undergoing coronary artery bypass grafting experiencing POAF. Methods and Results This was a register-based cohort study. Data from the WDHR (Western Denmark Heart Registry) were linked with the DNPR (Danish National Patient Register), the Danish National Prescription Register, and the Cause of Death Register. All stroke diagnoses were verified, and ischemic stroke cases were subclassified according to pathogenesis. Furthermore, investigations of all-cause mortality and the use of anticoagulation medicine for the individual patient were performed. A total of 7813 patients without a preoperative history of atrial fibrillation underwent isolated coronary artery bypass grafting between January 1, 2010, and December 31, 2018, in Western Denmark. POAF was registered in 2049 (26.2%) patients, and a postoperative ischemic stroke was registered in 195 (2.5%) of the patients. After adjustment, there was no difference in the risk of ischemic stroke (hazard ratio [HR], 1.08 [95% CI, 0.74-1.56]) or all-cause mortality (HR, 1.09 [95% CI, 0.98-1.23]) between patients who developed POAF and non-POAF patients. Although not statistically significant, patients with POAF had a higher incidence rate (IR; per 1000 patient-years) of cardioembolic stroke (IR, 1 [95% CI, 0.6-1.6] versus IR, 0.5 [95% CI, 0.3-0.8]), whereas non-POAF patients had a higher incidence rate of large-artery occlusion stroke (IR, 1.1 [95% CI, 0.8-1.5] versus IR, 0.7 [95% CI, 0.4-1.4]). Early initiation of anticoagulation medicine was not associated with a lower risk of ischemic stroke. However, patients with POAF were more likely to die of cardiovascular causes than non-POAF patients (P<0.001). Conclusions We found no difference in the adjusted risk of postoperative stroke or all-cause mortality in POAF versus non-POAF patients. Patients with POAF after coronary artery bypass grafting presented with a higher, although not significant, proportion of ischemic strokes of the cardioembolic type.

Validation of the national Danish ablation database: a retrospective, registry-based validation study

Aim.To validate the National Danish Ablation Database (NDAD) by investigating to what extent data in NDAD correspond to medical records.Type of study. Non-blinded, registry-based, retrospective, validation study. Material and methods. A sample of patients who underwent ablation for atrial fibrillation in Denmark between 1 January 2016 and 31 December 2016 were included. By utilizing medical records as gold standard, positive predictive (PPV) and negative predictive values (NPV) for NDAD were assessed and presented as five main categories: arrhythmia characteristics, demographics, cardiac history, complications, and medication. PPV's and NPV's exceeding 90% were considered as high agreement. Results. 597 patients (71.0% males) were included in the study. Median age was 63.1 (IQR: 54.9-68.4) years. The median PPV and NPV estimates across all variables were respectively 90.4% (95% CI: 68%-95.2%) (PPV) and 99.4% (95% CI: 98.4%-99.8%) (NPV) at baseline, and 91.7% (95% CI: 67.4%-95.4%) (PPV) and 99.3% (98.2%-99.3%) (NPV) at follow-up. Conclusion. The data registered in NDAD agrees to a great extent with the patients' medical records, suggesting NDAD is a database with high validity. As a result of low complication rate, the PPV- and NPV-estimates among complication variables were prone to somewhat greater uncertainty compared to the rest.

Safety and efficacy of direct oral anticoagulants in patients with anaemia and atrial fibrillation: an observational nationwide Danish cohort study

AIMS

The aim of this study was to evaluate the risk of stroke and bleeding among patients with atrial fibrillation (AF) treated with direct oral anticoagulants (DOACs) despite anaemia at treatment initiation time.

METHODS AND RESULTS

All Danish patients (N = 41 321) diagnosed with incident AF, having a baseline haemoglobin (Hb), and subsequently initiated DOAC therapy between 2012 and 2019 were identified through administrative registry databases. Patients with anaemia were subdivided according to the World Health Organization classification of anaemia and evaluated regarding risk of stroke and composite bleeding endpoint [hospitalization due to urogenital, gastrointestinal (GI), or intracranial bleeding or epistaxis]. Standardized absolute 1-year risks of stroke and composite bleeding endpoint were calculated using multivariable Cox regression analyses. The standardized absolute 1-year risk difference for composite bleeding increased by 0.96% [95% confidence interval (CI) 0.38-1.54] for patients with moderate/severe anaemia compared with patients with no anaemia. This risk was mainly driven by an increase in standardized absolute 1-year risk for serious GI bleeding, which increased by 0.41% (95% CI 0.19-0.63). No significant difference in standardized absolute 1-year bleeding risk was observed among patients with mild anaemia compared with patients with no anaemia 0.36% (95% CI -0.10 to 0.82). No significant difference in standardized absolute 1-year risk of stroke was observed among patients with mild anaemia, -0.16% (95% CI -0.13 to 0.15), and moderate/severe anaemia, -0.47% (95% CI -0.16 to 0.19), compared with patients with no anaemia.

CONCLUSION

For AF patients receiving DOACs, moderate/severe anaemia is a risk factor for serious GI bleeding, while stroke risk is the same regardless of whether anaemia was present at baseline or not.

Heart failure hospitalizations and diuretic use before and after first-time pulmonary vein isolation ablation for atrial fibrillation among patients with heart failure

Background

Small randomized clinical trials have found that patients with heart failure (HF) and atrial fibrillation (AF) randomized to an ablation strategy for AF experienced improved cardiovascular outcomes. We examined the relation in routine clinical practice.

Purpose

We aimed to assess if first-time pulmonary vein isolation ablation (PVI) for AF among patients with HF was associated with decrease in HF hospital admissions rates and furosemide dosage in the year after PVI compared with the year before.

Methods

We identified patients with HF and available left ventricular ejection fraction (LVEF) treated with a first-time PVI using the Danish Ablation Registry, and alive at 1-year follow-up. Patient comorbidities and concomitant pharmacotherapy (including furosemide dosage and HF hospital admissions) were identified utilizing Danish nationwide registries. For inclusion, patients were required to have been diagnosed with HF in an in- or outpatient setting &lt;10 years of first-time PVI or have a LVEF at the time of PVI ≤45%. Patients were grouped according to LVEF at time of PVI: ≤35%, 36–45%, and &gt;45%. For comparison of HF hospital admission and furosemide usage before and after PVI, McNemars test were used. Wilcox signed-rank test were used to test difference in furosemide dosage before and after PVI.

Results

We identified 668/3450 patients with HF treated with first-time PVI for AF between 2010–2017 (median age 62 years [Q1,Q3=56,69 years], 81% male, and median LVEF 45% [Q1,Q3=40,60%]). Of these, 13 patients (2%) died during one-year follow-up. Overall, 36% of patients with HF had one or more HF hospital admissions the year before PVI compared with 7% in the year after PVI (p&lt;0.0001) (Figure 1). Patients with LVEF ≤35% had the highest proportion of HF hospital admissions the year before PVI (53%) and was reduced more than 4-fold (13%) in the year after first-time PVI, with consistent findings in all LVEF groups (Figure 1). At the time of PVI, 36% of patients with HF were treated with furosemide compared with 30% in the year after PVI (p&lt;0.0001) (Figure 2). Moreover, we identified significant reductions in furosemide dose in the year after PVI compared with the year before (median dose 60 mg [Q1,Q3=30,80 mg] and 20 mg [Q1,Q3=0,60 mg], respectively, p=0.001). Here, reductions in furosemide requirements were consistent across LVEF subgroups.

Conclusion

Patients with HF treated with a first-time PVI strategy for AF had a 5-fold decrease in HF hospital admissions in the following year compared with the year before PVI. Among patients treated with furosemide at time of PVI, significant reductions in dose one year after PVI was identified but also significant reductions in proportion of patients requiring any furosemide at all.

Funding Acknowledgement

Type of funding sources: None.

Risk of lead explantation after first-time implantation of cardiac implantable electronic device as a function of comorbidity: a nationwide study

Background

The benefit of cardiac implantable electronic devices (CIEDs) is challenged by the risk of procedure-related complications and lead explantation. Whether patient comorbidity burden is associated with risk of lead explantation &lt;6 months of implantation is unknown.

Purpose

We assessed the risk of lead explantation and its association with comorbidity burden within 6 months after first-time CIED implantation.

Methods

The study population comprised patients ≥18 years old with first-time CIED implantation (i.e., pacemaker [PM], implantable cardioverter defibrillator [ICD], and cardiac resynchronisation therapy with defibrillator [CRT-D] or without [CRT-P]) using Danish nationwide registries including the Danish Pacemaker and ICD registry (1 January 2000 to 30 June 2018). Patients were followed from their first-time CIED implantation and 6 months forward. Patient comorbidity burden was categorised in four groups according to the Charlson Comorbidity Index (CCI) score: 0 (none), 1–2 (mild), 3–4 (moderate), and ≥5 (severe). Multivariable cause-specific Cox regression was performed to assess risk of lead explantation according to comorbidity burden, with death as competing risk. Comorbidity burden was adjusted for sex, age, type of CIED, and body mass index categories.

Results

We identified 73,491 patients with first-time CIED implantation including 55,733 (75.8%) with PM, 11,351 (15.5%) with ICD, 2,989 (4.1%) with CRT-P, and 3,418 (4.7%) with CRT-D. In total, 1,049 (1.4%) patients underwent lead explantation. The median age of the study population was 75.1 years [25th-75th percentile 66.2–82.5 years], and 62.1% were male. Patients undergoing lead explantation had higher median CCI score, compared with those not undergoing lead explantation (2 [1–3] and 1 [0–3], respectively). The median age and distribution of sex were similar in both groups. In the multivariable Cox regression model (Figure 1), an increase in patient comorbidity burden was associated with higher hazard ratio [HR] of lead explantation, compared with CCI score 0 (CCI score 1–2: HR=1.38 [95% confidence interval [CI]: 1.12–1.69], CCI score 3–4: HR=1.61 [95% CI: 1.28–2.03], and CCI score ≥5: HR=1.60 [95% CI: 1.25–2.05]).

Conclusion

Risk of lead explantation within 6 months after first-time implantation of cardiac implantable electronic device was 1.4% and associated with higher comorbidity burden.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Independent Research Fund Denmark

Incidence in atrial fibrillation in Denmark in relation to country of origin: a nationwide register-based study

Background

Immigrants' healthcare needs can be a considerable challenge, as their risk profile can differ from the native population, and they may experience barriers to accessing health services in recipient countries. Immigration is projected to increase further due to conflicts and climate changes, and awareness on immigrants' health status is therefore warranted. Atrial fibrillation (AF) is the most common sustained arrhythmia with an estimated prevalence of approximately 2%. However, there is a paucity of data on AF epidemiology among immigrants.

Purpose

The aim of this study is to examine incidence of AF hospital diagnoses according to country of origin and to study if there is a difference in risk between immigrants and Danish born individuals.

Methods

The study period included 1st of January 1998 to 31st of December 2017 and the population consisted of all Danish citizens aged 45 or older. We included individuals as they turned 45 during the study period. Individuals who had been diagnosed with AF were excluded. Data was obtained from the Danish National Patient Registry and the Civil Registration System. Country of origin was based on the ten most represented counties in the population. Immigrants were defined as people born outside Denmark with none of the parents being both Danish citizens and born in Denmark. AF was defined as a hospital diagnosis according to international Classification of Diseases (ICD) version 8 and 10. Poisson regression were used to compute relative risk (RR) and associated 95% confidence intervals (CI). RRs were adjusted for sex, age, socioeconomic status, visits to general practitioner and comorbidity.

Results

The study population consist of 3,596,234 Danish-Born and 215,401 immigrants. A total of 334,636 had an incident AF diagnosis during the study period. Compared to Danish-born individuals, migrants from the Nordic countries had a higher adjusted RR of being diagnosed with AF: Norway 1.21 [95% CI: 1.05; 1.40], Sweden 1.16 [95% CI: 0.99; 1.35] and Germany 1.17 [95% CI: 1.06; 1.28]. In contrast, lower adjusted RRs were observed for individuals from Poland (0.82 [95% CI: 0.67; 1.01]), UK (0.89 [95% CI: 0.73; 1.08]), and the US (0.95 [95% CI: 0.72; 1.25]), respectively, and in particular for individuals from the non-Western countries: Turkey (0.49 [95% CI: 0.40; 0.59], Iran (0.48 [95% CI: 0.36; 0.65]), Iraq (0.32 [95% CI: 0.22; 0.45] and Bosnia-Herzegovina (0.63 [95% CI: 0.49; 0.79]).

Conclusion

Substantial variation in the incidence rate of incident AF hospital diagnoses according to country of origin. Further studies are warranted in order to clarify to what extent these differences reflets true differences in AF incidence or ethnic inequalities in the detection of AF in the health care system.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Karen Elise Jensen Foundation

History of betablocker treatment breaks and risk of ventricular tachyarrhythmias among patients with heart failure and implantable cardioverter defibrillator: a nationwide cohort study

Background

Beta-blockers have in randomized clinical trials been shown to reduce the risk of life-threatening arrhythmias and sudden cardiac death (SCD) in patients with heart failure (HF), and treatment is a class 1A recommendation in current guidelines. Thus, beta-blocker treatment breaks (i.e. planned break, beta-blocker related side-effects, or poor adherence) may increase risk of life-threatening arrhythmias and SCD. Whether patients with HF and a history of beta-blocker treatment breaks before implantable cardioverter defibrillator (ICD) is associated with increased risk of device related therapy and mortality is largely unknown.

Aims

In patients with HF and an ICD alone or combined with cardiac resynchronization therapy (CRT-D), we examined the association between a history of a beta-blocker treatment breaks prior to device implantation and the risk of appropriate and inappropriate device related therapy (i.e., anti-tachycardia pacing [ATP] or DC shock [DC]), and all-cause mortality.

Methods

Using the Danish Pacemaker and ICD Registry, we identified all patients with HF receiving a first-time ICD (2000–2018). Beta-blocker treatment breaks &gt;60 consecutive days up to 3 years prior to device implantation were identified using the National Prescription Registry. Patients were able to switch between beta-blockers and were required to be in treatment at the time of implantation. We used multivariable Cox regressions to compare the 1-year risks of device-related therapy and all-cause mortality between patients with and without a history of a beta-blocker treatment break.

Results

We identified 9,239 patients with HF and an ICD (82.6% male; median age 67 years). A total of 82.5% had ischemic heart disease, 33.9% atrial fibrillation, and 33.1% of ICDs were secondary prophylaxis. During one-year follow-up, 5.7% of all patients died and appropriate DC and appropriate ATP was identified for 3.9% and 6.7% of patients, respectively. Overall, 14.6% of all HF patients had one or more beta-blocker treatment break &gt;60 days. Compared with HF patients with no history of treatment breaks, a history of treatment breaks &gt;60 days were associated with increased risk of appropriate DC (hazard ratio (HR)=1.33; 95% confidence interval [CI], 1.02–1.73) and appropriate ATP (HR 1.30; CI, 1.06–1.59), but also inappropriate DC and ATP therapy (Figure 1). There was no difference between groups with respect to all-cause mortality (HR=0.96; CI: 0.76–1.22). Treatment breaks of &gt;30 or &gt;90 days were also evaluated and yielded similar results as the main analysis.

Conclusion

Patients with heart failure who had a history of treatment breaks with beta-blockers prior to ICD implantation was associated with a higher 1-year risk of appropriate and inappropriate shocks and anti-tachycardia pacing, but not all-cause mortality.

Funding Acknowledgement

Type of funding sources: None.

Staphylococcus aureus bacteremia in Danish patients with cardiac implantable electronic devices: an explorative epidemiological study

Background

Device-related infection is the most common serious complication in patients with cardiac implantable electronic devices (CIED). Staphylococcus aureus accounts for up to 30% of CIED-related infections. There is a lack of scientific literature investigating risk of Staphylococcus aureus bacteremia (SAB) in CIED-patients.

Purpose

We aimed to describe the risk of SAB in Danish patients with a CIED through the years 2000–2018 compared to the background population.

Methods

Patients who received a CIED from 2000–2018 were identified from The Danish National Pacemaker and ICD Register. Patients were matched 1:5 on age and gender with the background population. We identified the primary endpoint of first time SAB from The National Danish Staphylococcus Aureus Bacteremia Database. The cumulative incidence of SAB was calculated using the Aalen-Johansen estimator, adding competing risk of death into account. Hazard ratios were estimated by Cox regression models adjusting for age and gender. Crude rates of relapse SAB, defined as a new SAB episode 14–180 days after first SAB, and device extractions were reported for all patients who survived 14 days from SAB diagnosis.

Results

We identified 79,324 CIED-patients (pacemaker (PM) = 61,227; Implantable Cardioverter Defibrillator (ICD) = 11,635; Cardiac resynchronization therapy, PM or ICD (CRT) = 6,364 and 396,590 matched controls (median age 75.5±13.3 years; 61% males). Age and gender distribution differed significantly by device type (age: PM 76.1±12.1; ICD 62.4±13.4; CRT 68.0±11.1; males: PM: 55.6%, ICD% 75.5: CRT: 80.9%). Across a mean follow-up of 5.9 (±4.6) years, we observed first episode of SAB in 1,430 (1.8%) CIED-patients, compared to 2,599 (0.7%) patients in the control population (p&lt;0.001).

The 10-year cumulative incidence of SAB was 1.0% for controls and 2.2% for CIED patients. The risk of SAB differed substantially by device type (Figure 1). Compared to controls and adjusted for age and gender, increasing hazard ratios for SAB were observed with more advanced devices: PM 1.12 (1.11–1.13); ICD 1.36 (1.33–1.39); CRT 1.55 (1.51–1.59). However, CIED-patients with SAB did not have higher 30-day mortality rates than the non-CIED control population with SAB (Controls 34.8%; PM 35.1%; ICD 28.1% CRT 26.1%, p=0.016). Out of all SAB patients who survived 14 days from SAB diagnosis (Controls=1,672; CIED=1,107), relapse SAB occurred in 52 (3.1%) controls and in 51 (4.6%) CIED-patients (PM 4.0%; ICD 5.8%; CRT 6.3%). Device extraction within 14 and 30 days from SAB diagnosis was undertaken in less than 30% of the CIED-patients (PM: 11.3/13.6%; ICD: 22.7/27.5%; CRT: 17.4/20.1%).

Conclusion

The occurrence of SAB was higher in CIED patients compared with controls and increased with more advanced devices. There was no difference in 30-day mortality after SAB between CIED patients and controls. Relapse SAB occurred in less than 7%, despite a low percentage of early device extractions.

Funding Acknowledgement

Type of funding sources: None.

Risk of pacing-induced cardiomyopathy in patients with high-degree atrioventricular block – comparison between right ventricular pacing sites using computed tomography

Background

Right ventricular (RV) pacing may induce significant left ventricular (LV) dyssynchrony resulting in pacing-induced cardiomyopathy (PICM). LV activation sequence is affected by RV pacing site and previous studies suggest that RV septal pacing may be superior compared to traditional RV apical pacing. However, results are conflicting and randomized controlled trials have failed to show clear benefits from RV septal pacing. Traditionally, studies have applied fluoroscopy to determine RV lead implantation site. However, locating pacing site using this method is known to be inaccurate and poorly reproducible compared with cardiac computed tomography (CT). The purpose of our study was to evaluate the association between RV pacing site determined by cardiac CT and risk of PICM.

Methods

We retrospectively included 153 patients with pre-implant LV ejection fraction (LVEF) ≥50% who underwent fluoroscopy-guided dual chamber pacemaker implantation due to high-degree atrioventricular block between March 2012 and May 2020. All patients attended a follow-up visit including cardiac CT and transthoracic echocardiography. RV lead position was evaluated from CT dividing the RV into three segments: apical, septum or free wall (Figure 1). Furthermore, RV lead position estimated by the implanting physician, using fluoroscopy during pacemaker implantation, was retrieved from medical records. The primary endpoint was PICM defined as ≥10% decrease in LVEF from time of pacemaker implantation to follow-up, resulting in LVEF &lt;50%.

Results

Mean duration of follow-up was 3.7 years (range 2.1–8.7). The implanting physician estimated 131 (85.6%) leads to be located septal, 5 (3.3%) located non-septal and 17 (11.1%) were unknown. Based on CT, 48 (31.4%) leads were located septal and 105 (68.6%) were located non-septal of which 31 were located on the free wall (20.4%). With CT as the golden standard, 47 (35%) leads were estimated correctly during fluoroscopy-guided implantation. No significant differences between patient characteristics in the CT-estimated septal and non-septal groups were observed except for ischemic heart disease (P=0.05) (Table 1). There were 16 (33.3%) patients in the septal group who developed PICM compared to 31 (29.5%) in the non-septal group (P=0.6). Adjusting for ischemic heart disease did not change this result. In the septal group, the change in LVEF from baseline to follow-up was −9.0±10.4% compared to −7.5±9.1% in the non-septal group (P=0.4).

Conclusion

In total 31% developed PICM despite having a normal pre-implant LVEF with no observed difference between RV septal and non-septal pacing. With CT as the golden standard, RV leads were inaccurately located during fluoroscopy-guided pacemaker implantation with only 35% being located correctly. Misclassification of pacing sites in previous studies may have contributed to the inconsistent results.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Svend Andersens FondKarl G Andersens Fond

Long-term risk of replacement of cardiovascular implantable electronic devices following external cardioversion

Introduction

External cardioversion (ECV) with transthoracic shock is a recommended and important part of the rhythm control strategy regardless of cardiovascular implantable electronic devices (CIED). Studies and case reports have demonstrated rare, but serious CIED malfunctions related to the ECV procedure. However, follow-up data on contemporary CIEDs undergoing ECV procedures are limited. The aim of this study is to investigate the long-term risk of generator replacements following an ECV procedure.

Methods

All CIED implants and surgical re-interventions in Denmark were identified in the Danish Pacemaker and ICD Register from January 2005 to April 2021. The ECV procedures were identified in the Danish National Patient Registry from January 2010 to February 2019. For each patient undergoing ECV, five matched (age, sex, and type of CIED) controls without previous ECV were identified. Time to generator replacement was estimated using competing risk analyses, with death, extraction and up-/down-grade being competing events. Risks were estimated by the pseudo-observation method.

Results

We identified in total 3,924 ECV-events in 2,610 CIED patients with 74.4% male. Mean age of patients at first ECV-procedure were 68.6±11.7 years, and median implant time was 1.5 year. The type of CIED included 50% of pacemakers, 28% of Implantable Cardioverter Defibrillators, and 22% of Cardiac Resynchronization Therapy-systems. During the first 5 years of follow-up, 451 (17.3%) of the shock-exposed devices were replaced vs. 2,000 (15.2%) of the unexposed devices. The relative risks (RR) of device replacement were 1.43 (95% CI: 0.5; 2.4) after 12 months, 1.44 (95% CI: 0.1; 2.8) after 24 months, and −0.53 (95% CI: −2.8; 1.7) after 5 years. The cumulated incidence of first endpoint: Replacement, death, extraction, and up-/down-grade are illustrated in Figure 1. A larger proportion of patients died in the shock-exposed group with n=427 (16.4%) compared to n=1,588 (12.2%) in the unexposed group during 5-years of follow-up with RR=3.2 (95% CI: 1.2; 5.3) of dead before other events.

Conclusion

Contemporary CIEDs do not indicate different risk of generator replacement following external cardioversion with transthoracic shocks. Shock-exposed device patients were more prone for extraction and death.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): This is work was financed by Department of Cardiology, Aalborg University Hospital and supported by Karl G. Andersen foundation.

Risk of pacemaker implantation after femur fracture in patients with and without a history syncope: a Danish nationwide registry-based follow-up study

BACKGROUND

It has previously been described that fall-associated injuries including fractures are commonly observed among patients with bradyarrhythmia. However, knowledge on the risk of pacemaker implantation after admission due to femur fracture from large population-based epidemiologic data is lacking. Therefore, we investigated the risk of pacemaker implantation following femur fracture in patients with and without a history of previous syncope.

METHODS

All patients with femur fracture between 2005-2017 were identified using the Danish Nationwide Patient Registry. Among these, patients already having a pacemaker were excluded. Primary outcome was one-year risk of pacemaker implantation and secondary outcome was one-year all-cause mortality. Multivariable logistic regression was used to obtain absolute and relative risks of the study endpoint in relation to patients with versus without history of syncope and standardized to the age, sex, selected comorbidity and pharmacotherapy distribution of all patients.

RESULTS

Of 93,093 patients with femur fracture, 5508 (5.9%) had a history of syncope within five years. Patients with prior syncope were slightly older (84 vs. 83 years), more often male (33.6% vs. 29.4%), and had more often comorbidities relative to those without history of syncope. All-cause mortality was significantly higher among those with previous history of syncope compared to those without previous syncope (29.9% vs. 28.6%, P = 0.021). The relative mortality risk was 1.05 (95% CI: 1.01-1.09, P = 0.021). A total of 695 (0.8%) patients underwent pacemaker implantation within 5 years following femur fracture, and a significantly higher proportion of patients with syncope had a pacemaker implanted within one year (1.6% vs. 0.7%, P < 0.001; relative risk, 2.01 [95% CI: 1.55-2.46]).

CONCLUSIONS

In patients with femur fracture, a history of syncope was significantly associated with a higher one-year risk of pacemaker implantation.

Non-invasive estimation of QLV from the standard 12-lead ECG in patients with left bundle branch block

Background: Cardiac resynchronization therapy (CRT) is a treatment for patients with heart failure and electrical dyssynchrony, i.e., left bundle branch block (LBBB) ECG pattern. CRT resynchronizes ventricular contraction with a right ventricle (RV) and a left ventricle (LV) pacemaker lead. Positioning the LV lead in the latest electrically activated region (measured from Q wave onset in the ECG to LV sensing by the left pacemaker electrode [QLV]) is associated with favorable outcome. However, optimal LV lead placement is limited by coronary venous anatomy and the inability to measure QLV non-invasively before implantation. We propose a novel non-invasive method for estimating QLV in sinus-rhythm from the standard 12-lead ECG.

Methods: We obtained 12-lead ECG, LV electrograms and LV lead position in a standard LV 17-segment model from procedural recordings from 135 standard CRT recipients. QLV duration was measured post-operatively. Using a generic heart geometry and corresponding forward model for ECG computation, the electrical activation pattern of the heart was fitted to best match the 12-lead ECG in an iterative optimization procedure. This procedure initialized six activation sites associated with the His-Purkinje system. The initial timing of each site was based on the directions of the vectorcardiogram (VCG). Timing and position of the sites were then changed iteratively to improve the match between simulated and measured ECG. Noninvasive estimation of QLV was done by calculating the time difference between Q-onset on the computed ECG and the activation time corresponding to centroidal epicardial activation time of the segment where the LV electrode is positioned. The estimated QLV was compared to the measured QLV. Further, the distance between the actual LV position and the estimated LV position was computed from the generic ventricular model.

Results: On average there was no difference between QLV measured from procedural recordings and non-invasive estimation of QLV (ΔQLV=−3.0±22.5 ms, p=0.12). Median distance between actual LV pacing site and the estimated pacing site was 18.6 mm (IQR 17.3 mm).

Conclusion: Using the standard 12-lead ECG and a generic heart model it is possible to accurately estimate QLV. This method may potentially be used to support patient selection, optimize implant procedures, and to simulate optimal stimulation parameters prior to pacemaker implantation.

Epidemiology and impact of frailty in patients with atrial fibrillation in Europe

BACKGROUND

Frailty is a medical syndrome characterised by reduced physiological reserve and increased vulnerability to stressors. Data regarding the relationship between frailty and atrial fibrillation (AF) are still inconsistent.

OBJECTIVES

We aim to perform a comprehensive evaluation of frailty in a large European cohort of AF patients.

METHODS

A 40-item frailty index (FI) was built according to the accumulation of deficits model in the AF patients enrolled in the ESC-EHRA EORP-AF General Long-Term Registry. Association of baseline characteristics, clinical management, quality of life, healthcare resources use and risk of outcomes with frailty was examined.

RESULTS

Among 10,177 patients [mean age (standard deviation) 69.0 (11.4) years, 4,103 (40.3%) females], 6,066 (59.6%) were pre-frail and 2,172 (21.3%) were frail, whereas only 1,939 (19.1%) were considered robust. Baseline thromboembolic and bleeding risks were independently associated with increasing FI. Frail patients with AF were less likely to be treated with oral anticoagulants (OACs) (odds ratio 0.70, 95% confidence interval 0.55-0.89), especially with non-vitamin K antagonist OACs and managed with a rhythm control strategy, compared with robust patients. Increasing frailty was associated with a higher risk for all outcomes examined, with a non-linear exponential relationship. The use of OAC was associated with a lower risk of outcomes, except in patients with very/extremely high frailty.

CONCLUSIONS

In this large cohort of AF patients, there was a high burden of frailty, influencing clinical management and risk of adverse outcomes. The clinical benefit of OAC is maintained in patients with high frailty, but not in very high/extremely frail ones.

Palpebral Fissure Response to Phenylephrine Indicates Autonomic Dysfunction in Patients With Type 1 Diabetes and Polyneuropathy

Purpose

The superior and inferior tarsal muscles are sympathetically innervated smooth muscles. Long-term diabetes often leads to microvascular complications, such as, retinopathy and autonomic neuropathy. We hypothesized that diabetes induces (1) sympathetic paresis in the superior and inferior tarsal muscles and that this measure is associated with (2) the severity of diabetic retinopathy, (3) the duration of diabetes, and (4) autonomic function. In addition, association between the severity of retinopathy and autonomic function was investigated.

Methods

Forty-eight participants with long-term type 1 diabetes and confirmed distal symmetrical polyneuropathy were included. Palpebral fissure heights were measured bilaterally in response to topically applied 10% phenylephrine to the right eye. The presence of proliferative diabetic retinopathy (PDR) or nonproliferative diabetic retinopathy and disease duration were denoted. Time and frequency derived heart rate variability parameters obtained from 24-hour continuous electrocardiography were recorded.

Results

The difference in palpebral fissure heights between phenylephrine treated and untreated eyes (∆PFH) was 1.02 mm ± 0.29 (P = 0.001). The ∆PFH was significantly lower in the PDR group (0.41 mm ± 0.43 vs. 1.27 mm ± 1.0), F(1,35) = 5.26, P = 0.011. The ∆PFH was lower with increasing diabetes duration, r(37) = -0.612, P = 0.000. Further, the ∆PFH was lower with diminished autonomic function assessed as total frequency power in electrocardiogram (r = 0.417, P = 0.014), and sympathetic measures of very low (r = 0.437, P = 0.010) and low frequency power (r = 0.384, P = 0.025).

Conclusions

The ∆PFH is a simple ambulatory sympathetic measure, which was associated with the presence of PDR, disease duration, and autonomic function. Consequently, ∆PFH could potentially be an inexpensive and sensitive clinical indicator of autonomic dysfunction.

External cardioversion of atrial fibrillation and flutter in patients with cardiac implantable electrical devices

Funding Acknowledgements

Type of funding sources: None.

Introduction

Atrial tachyarrhythmias are often treated with external cardioversion (ECV) with direct current shocks in patients with potentially electrically sensitive cardiovascular implantable electronic devices (CIED). Long-term follow-up data on contemporary pacemakers and implantable cardioverter defibrillators (ICD) undergoing ECV is sparsely described. This study investigated shock-related complications and impact on CIEDs.

Methods

All ECV procedures of atrial fibrillation and flutter from 2010 to 2020 in patients with CIED performed at a tertiary hospital (Denmark) were identified in the Danish National Patient Registry. Data on device interrogation before and after ECV and procedure-related complications were retrieved retrospectively by review of medical records.

Results

We analysed 664 ECV-events performed in 362 CIEDs, median implant time 1.5 year. Mean age of patients at first ECV-event were 69.4±9.7 years and 72.2% were men. We identified two cases of major programming changes and two cases of premature battery depletion (≤3 years after generator implant) following ECV. Minor shock-related device changes were found for impedances, atrial sensing values and pacing thresholds of right ventricle lead. In two cases increased pacing threshold of right ventricle leads following ECV triggered exit-blocks after few months. No patients died due to shock-related device dysfunctions.

Conclusion

Following external cardioversion with transthoracic direct current shocks, sporadic (&lt;1%) but potentially critical changes in device function were identified in patients with contemporary pacemakers and implantable cardioverter-defibrillators. The present study suggests that routine post-cardioversion device interrogation is imperative for patient safety.

A webbased intervention for patients with an implantable cardioverter defibrillator, a qualitative study of nurses experiences

Funding Acknowledgements

Type of funding sources: None.

Background

Implantable cardioverter defibrillator (ICD) therapy is the gold standard for prevention of sudden cardiac death. Patients generally adapt well to living with an ICD, but 20% have difficulties adjusting, with increased risk of anxiety and depression and decreased quality of life. New web-based interventions engaging patients with an ICD might be efficient, but there is sparse knowledge on experiences with web-based care from the perspective of cardiac nurses.

Purpose

The aim of the study was to explore cardiac nurses’ experiences with a web-based intervention designed to empower patients with an ICD.

Methods

We conducted a qualitative study based on semi-structured interviews. The informants (n=9) were experienced cardiac nurses across 5 Danish university hospitals. They were delivering a comprehensive web-based intervention for patients with an ICD, including patient education, chats, monitoring of anxiety and depression and a patient forum. The intervention was tested in a randomized controlled trial. The interviews were transcribed verbatim, coded and analyzed using qualitative content analysis with NVivo software.

Results

We identified an overall theme: "Between traditional nursing and modern eHealth". The theme emerged from six categories, each covering three or four subcategories (Figure 1). The categories were: (1) comprehensive intervention, (2) patient-related differences in engagement, (3) following the protocol is a balancing act, (4) online communication challenges patient contact, (5) professional collaboration varies, and (6) an intervention with potential. Cardiac nurses were in general positive towards the concept of this web-based intervention and believe it holds a large potential. On the other hand, they were challenged by not establishing a personal relation and by losing face-to-face contact with patients, which they found valuable for getting a feeling for patients’ wellbeing and potential mental health issues. Ensuring face-to-face contact by either starting the intervention with a personal contact or including the possibility of video contacts might enhance the value of web-based interventions from the perspective of cardiac nurses. The nurses found the intervention especially suitable for patients who had suffered a cardiac arrest.

Conclusion

Specific training in eHealth communication is necessary as web-based care entails a shift in nursing role and a new format of communication for cardiac nurses. Future evaluations of web-based cardiac rehabilitation interventions in clinical practice are needed to assess the potential impact in "real-life" cardiac care.

Novel non-invasive 12-lead ECG-based imaging method with potential to guide and optimise right ventricular lead implantation

Funding Acknowledgements

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Svend Andersens Foundation

Karl G Andersens Foundation

Helsefonden

Background

Right ventricular (RV) pacing may induce electrical and mechanical dyssynchrony which may lead to heart failure. Often, the physician aims for lead implantation at the RV septum as this is expected to result in a more physiologic activation compared to alternative RV lead locations. Fluoroscopy, often in combination with QRS morphology derived from the 12-lead ECG, is used to guide lead implantation. However, this method is inaccurate and can result in a non-optimal RV lead location. We present a novel non-invasive method to create patient-specific 3D electrical activation maps from the 12-lead ECG that has potential to support RV lead implantation.

Methods

Data from 34 patients with an implanted dual chamber pacemaker were used. A contrast-enhanced cardiac CT scan showing the RV lead implantation site was obtained as well as recording of a 12-lead ECG during RV pacing together with a 3D photo documenting the ECG electrode positions. Discrete patient-specific torso and heart models were created from the CT scans. Each torso model was merged with the 3D photo for precise placement of the ECG electrodes in relation to the heart (figure 1). Combining the 12-lead ECGs and the heart/torso models, patient-specific 3D electrical activation maps originating from the RV were created using a novel inverse-ECG technique applying electrophysiological rules. The accuracy of the inverse-ECG method was determined by comparing the earliest site of activation from the 3D activation map with the known RV insertion site marked on the CT scan.

Results

Documented by the implanting physician in the medical records, 33 RV leads were estimated to be septal and one apical. Estimated from the CT scan 9 leads were placed septal, 18 apical and 7 on the free wall. The mean geodesic distance between the initial site of activation in the 3D activation map and the marked RV insertion site from CT was 13.6 ±5.7 mm (range 4.3-28.6). The distance for each patient is shown in figure 2. The initial site of activation was constrained to the discrete nodes of the ventricular model whereas the marker for RV lead position was localized freely on the CT scan. The average distance from the RV CT marker to the nearest discrete node was 4.3 ±2.2 mm. Correcting for this error, the geodesic distance between the initial site of activation and RV CT marker was 9.3 ±5.4 mm (range 0.0-24.6). The average time used for 3D activation map computation was 1.1 ±0.4 s per ECG.

Conclusions

We demonstrated a novel non-invasive 12-lead ECG-based method to accurately and effectively localize the RV lead in relation to the ventricular anatomy during RV pacing. Furthermore, we confirmed that the RV lead was often implanted in an unintended position. With further advancements, this method has the potential to support physicians during pacemaker implantation to ensure optimal RV lead positioning. Further studies are needed to confirm the accuracy.

Early mortality and complications following first-time catheter ablation of atrial fibrillation in a nationwide cohort

Funding Acknowledgements

Type of funding sources: None.

Background

Atrial fibrillation (AF) is the most common clinical arrhythmia. Pulmonary vein isolation (PVI) by catheter ablation has become a cornerstone in the treatment of AF. Serious complications to PVI have been reported to be at an acceptable level and risk of death after AF ablation is low.

Purpose

In a contemporary nationwide cohort of patients undergoing first-time PVI by catheter ablation, we wanted to investigate the 30-day mortality after ablation, and to examine risk and potential risk factors of PVI-related complications.

Methods

Population-based cohort study in patients who underwent first-time PVI by catheter ablation between 2011-2018 identified from the National Danish Ablation Registry. Primary outcome was early post-procedural mortality, defined as death of any cause within 30 days of index PVI procedure, or in connection to a hospitalization started within 30 days. Secondary outcomes were all-cause rehospitalization and complication, including postoperative infection, cardiac, vascular, neurological, vascular, and pulmonary complications within 30 days. Data on mortality and complications were collected from national health and administrative registries. Binary regression was used to estimate risk ratio (RR) with 95% confidence intervals (CI) for association between selected predictors and any complication, and adjusted gender, age, BMI, prior ablation, calendar period (ablation from 2011-2013, 2014-2016, and &gt;2016).

Results

We included 8560 patients. Median age was 62, 66% were men, 12% had a history of heart failure, and median CHA2DS2VASc score was 1 (Interquartile range [IQR]; 1-2). Charlton Comorbidity index (CCI) was none in 66%, moderate in 29% and severe in 5%. A total of 10 (0.12%) patients died within 30 days of ablation, of which 4 patients died during initial hospitalization. Median time to death was 20 (IQR, 12 to 29) days. Patients who died were more likely to have experienced a procedure-related complication (40% vs. 4%, P&lt;0.001). Procedure-related complications occurred in 298 (3.5%), and the risk was 4.4%, 3.0% and 3.3% in the time periods between 2011-2013, 2014-2016 and &gt;2016, respectively. Most common complications were postoperative infection (26%), cardiac complication (26%), and vascular complications (18%). Complication risk was increased in patients with higher age (aRR, 65-74 year; 1.67 [1.32-2.11] and &gt;74 years; 2.48 [1.60-3.84]), moderate CCI (aRR 1.45 [1.14-1.83]), cardiovascular disease (aRR 1.52 [1.09-2.11]) and antithrombotic treatment (aRR 1.41 [1.05-1.89]). After first-time PVI, 1.963 (23%) patients were re-hospitalized within 30 days, and most common primary discharge diagnoses were AF (87%) and direct cardioversion was performed in 765 (39%) patients.

Conclusion

In a nationwide cohort of patients who underwent first-time PVI, number of deaths within 30 days of ablation was low (0.12%). Risk of complication was low and 23% of the patients were re-hospitalized within 30 days.

Association Between Newly Diagnosed Atrial Fibrillation and Work Disability (from a Nationwide Danish Cohort Study)

It is previously shown that cardiovascular conditions have a negative effect on the ability to work. However, it is unknown if incident atrial fibrillation (AF) influences the ability to work. We examined the association between AF and the risk of work disability and the influence of socioeconomic factors. All Danish residents with a hospital diagnosis of AF and aged ≥30 and ≤63 years in the period January 1, 2000, to September 31, 2014, were included and matched 1:10 with an AF-free gender and age-matched random person from the general population. Permanent social security benefit was used as a marker of work disability. Risk difference (RD) and 95% confidence interval (95% CI) of work disability were calculated over 15 months. The analyses were furthermore stratified in low, medium, and high levels of socioeconomic factors. In total, 28,059 patients with AF and 312,667 matched reference persons were included. The risk of receiving permanent social security benefits within 15 months was 4.5% (4.3% to 4.8%) for the AF cohort and 1.3% (95% CI 1.3% to 1.4%) for the matched reference cohort. Adjusted RD (95% CI) was 2.3% (2.0% to 2.5%). Stratified on income, RDs were higher in low-income groups (adjusted RD 3.7% [95% CI 3.1% to 4.3%]) versus high-income groups (RD 1.3% [1.0% to 1.5%]). In conclusion, the risk of work disability within 15 months after incident AF was more than 3 times as high in patients with AF compared with the general population, especially when comparing individuals in lower socioeconomic strata.

Disparities in oral anticoagulation initiation in patients with schizophrenia and atrial fibrillation: a nationwide cohort study

Aims

Schizophrenia is associated with poor anticoagulation control and clinical prognosis in patients with atrial fibrillation (AF). Little is known about initiation of oral anticoagulation therapy (OAC) in this patient population.

Methods

In the nationwide Danish health registries, we identified all patients with incident AF and schizophrenia with indication for OAC treatment. Patients with schizophrenia (n = 673) were matched 1:5 on sex, age, stroke risk score, and calendar‐period to incident AF patients without schizophrenia. We calculated absolute risk and risk difference (RD) of OAC initiation, adjusting for stroke and bleeding risk factors. Analyses were stratified by calendar period (2000–2011 and 2012–2018) to account for changes after the introduction of non‐vitamin K OACs (NOAC).

Results

Among patients with schizophrenia (mean age 69.5 years, 50.3% females), 33.7% initiated OAC within the first year after AF diagnosis, compared with 54.4% of patients without schizophrenia, corresponding to an adjusted RD of −20.7 (95% confidence interval [CI]: −24.7 to −16.7). OAC initiation increased over time regardless of schizophrenia status. During 2000–2011, 18.3% of patients with schizophrenia and 42.9% without schizophrenia initiated OAC (adjusted RD −23.6%, 95% CI −28.8 to −18.6). During 2012–2018, this was 48.5% and 65.7%, respectively (adjusted RD −14.4%, 95% CI −20.4 to −8.4).

Conclusion

Initiation of OAC was substantially lower among patients with AF and schizophrenia compared with matched AF peers. These findings accentuate the importance of close attention to disparities in initiation of OAC treatment, and potential missed opportunities for prevention of disabling strokes in AF patients with schizophrenia.

The prevalence of atrial fibrillation in Greenland: a register-based cross-sectional study based on disease classifications and prescriptions of oral anticoagulants

   Previous studies of the prevalence of atrial fibrillation (AF) in Greenland are based on either single-point electrocardiograms (ECGs) or patients admitted with stroke. This study estimates the prevalence of AF based on disease classifications in the electronic medical record system (EMR) and prescriptions of oral anticoagulants (OACs). Patients given a diagnose classification code for AF or atrial flutter or prescribed the vitamin K antagonist Warfarin or the direct-acting oral anticoagulant Rivaroxaban were identified in the EMR. Descriptive data and selected laboratory values were extracted, and a minimum CHA₂DS₂-VASc score was calculated for the 790 patients identified in the EMR (66% men). A total prevalence of AF of 1.4% was found in the general population (1.8% among men and 1.0% among women), with a significantly lower prevalence among women younger than 70 years. There was a significant increase in AF-prevalence with advancing age (p<0.001) for both men and women. A minimum CHA₂DS₂-VASc was estimated and app. 10% of the patients may be undertreated with OACs. The prevalence of AF found in this study is higher than that found in previous studies in Greenland and comparable to the prevalence found in other Western countries, indicating that AF is common in Greenland.

Perception of pharmacological prevention and subsequent non-adherence to medication in patients with ischaemic heart disease: a population-based cohort study

OBJECTIVE

A patient-focused approach is advocated to embody risk of non-adherence to medication and subsequent adverse clinical outcomes following ischaemic heart disease (IHD). This study aimed to explore how patient perceived information on pharmacological prevention was associated with subsequent non-adherence to medication (measured by non-initiation, non-implementation and non-persistence) in patients with incident IHD.

DESIGN

Cohort study.

SETTING

Denmark.

PARTICIPANTS

Register-based cohort of 829 patients with incident IHD in 2013.

MEASURES

Perception covered whether patients' experienced being adequately informed about their pharmacological prevention. Information on such was obtained from a survey and divided into 'Well informed', 'Moderately informed' and 'Poorly informed'. Information on baseline characteristics, and reimbursed prescriptions of medication (antiplatelets, statins, ACE-inhibitors/angiotensin receptor blockers and β-blockers) during follow-up were obtained by linkage to nationwide public registers. Non-initiation and non-implementation of medication, measured as proportion of days covered, were analysed by Poisson regression. Non-persistence to medication, measured as risk of discontinuation, was analysed by multivariable Cox proportional hazard regression.

PRIMARY AND SECONDARY OUTCOME MEASURES

Non-implementation and non-persistence to medication up to 365 days of follow-up were primary outcomes. Secondary outcomes included non-initiation as well as non-implementation and non-persistence to medication at 180 days of follow-up.

RESULTS

A dose-response association was in general found between perception of pharmacological prevention and risk of non-implementation and non-persistence. For example, the hazard of non-persistence to antiplatelets was 1.18 (95% CI 0.71 to 1.96) times higher for patients reporting 'Moderately informed' and 1.89 (95% CI 1.10 to 3.25) times higher for patients reporting 'Poorly informed', compared with patients reporting 'Well informed of perception of pharmacological prevention' up to 365 days of follow-up.

CONCLUSION

Lower levels of perception of pharmacological prevention were associated with subsequent non-implementation and non-persistence to medication in patients with incident IHD.