Cardiac implantable electronic device infections: prognostic value of the PADIT score and its cost-utility implications for antimicrobial envelope use in the United Kingdom

Background

The incidence of cardiac implantable electronic device (CIED) infections is rising.

Purpose

We examined the factors associated with CIED infection, assessed the prognostic power of the PADIT risk score, and modelled the cost-utility of selective TYRX antimicrobial envelope use for preventing CIED infections.

Methods

Data were extracted from 2016 to 2019, and included all de novo implants, generator changes and lead interventions for transvenous CIEDs at a high-volume UK centre. CIED infection was defined as hospitalisation for device infection within 12 months of a procedure. Cost-utility analysis was informed by standardised tariffs, and quality adjusted life year (QALY) and efficacy data was extrapolated from analysis of the WRAP-IT trial.

Results

6,035 patients underwent 7,383 procedures; CIED infection occurred in 59 individuals (0.8%). In addition to the constituents of the PADIT score, lead extraction (HR 3.3 (1.9–6.1), p<0.0001), C-reactive protein >50mg/l (HR 3.0 (1.4–6.4), p=0.005), re-intervention within two years (HR 10.1 (5.6–17.9), p<0.0001), and procedure duration over two hours (HR 2.6 (1.6–4.1), p=0.001) were independent predictors of infection. Increased PADIT score was strongly associated with infection (AUC: 0.82, HR per point increase: 1.36 (1.27–1.47), p<0.0001). A cost-utility model assigning TYRX envelopes to patients with PADIT scores ≥6 predicted a reduction in infections (number needed to treat: 72) and a cost per QALY gained within the UK's (NICE) cost-effectiveness threshold (£25,107).

Conclusions

The PADIT score was a powerful predictor of CIED infections in a heterogeneous population,and may facilitate cost-effective TYRX envelope allocation in selected high-risk patients.

Funding Acknowledgement

Type of funding sources: None.

Transseptal puncture for left atrial ablation: risk factors for cardiac tamponade and a proposed causative classification system

Background

Cardiac tamponade is a high morbidity complication of transseptal puncture (TSP).

Purpose

We examined the associations of TSP-related cardiac tamponade (TRCT) for all patients undergoing left atrial ablation at our centre from 2016–2020.

Methods

Patient and procedural variables were extracted retrospectively. Cases of cardiac tamponade were scrutinised to adjudicate TSP culpability. Adjusted multivariate analysis examined predictors of TRCT.

Results

3,239 consecutive TSPs were performed; cardiac tamponade occurred in 51 patients (incidence: 1.6%) and was adjudicated as TSP-related in 35 (incidence: 1.1%; 68.6% of all tamponades). Patients of above-median age (OR 2.4 (1.19–4.2), p=0.006) and those undergoing re-do procedures (OR 1.95 (1.29–3.43, p=0.042) were at higher risk of TRCT. Of the operator-dependent variables, choice of transseptal needle (Endrys vs Brockenbrough, p>0.1) or puncture sheath (Swartz vs Mullins vs Agilis vs Vizigo vs Cryosheath, all p>0.1) did not predict TRCT. Adjusting for operator, equipment and demographics, failure to cross the septum first pass increased TRCT risk (OR 4.42 (2.45–8.2), p=0.001), whilst top quartile operator experience (OR 0.4 (0.17–0.85, p=0.002), transoesophageal echocardiogram (TOE prevalence: 26%, OR 0.51 (0.11–0.94), p=0.023), and use of the SafeSept guidewire (OR 0.22 (0.08–0.62), p=0.001) reduced TRCT risk. An increase in SafeSept wire use over time (2016: 15.6%, 2020: 60.2%) correlated with an annual reduction in TRCT (R2=0.72, p<0.001) and was associated with a relative risk reduction of 70%.

Conclusions

During left atrial ablation, the independent predictors of TRCT were patient age, re-do procedure, operator experience, unsuccessful first pass, TOE-guidance, and use of the SafeSept wire. A novel classification system for the causes of cardiac tamponade is proposed (table 1); this may be of interest to clinical trialists or auditors evaluating patient safety.

Funding Acknowledgement

Type of funding sources: None.

ECG-I Phenotyping of Persistent AF Based on Driver Burden and Distribution to Predict Response to Pulmonary Vein Isolation (PHENOTYPE-AF)

BACKGROUND

This prospective trial sought to phenotype persistent AF based on AF mechanisms using ECGI mapping to determine whether this would predict long term freedom from arrhythmia after pulmonary vein isolation (PVI).

METHODS

Patients with persistent AF of < 2 years duration underwent cryoballoon PVI. ECGI mapping was performed prior to PVI to determine potential drivers (PDs) defined as rotational activations completing ≥ 1.5 revolutions or focal activations. The co-primary end point was the association between (1) PD burden (defined as the number of PD occurrences) and (2) PD distribution (defined as the number of segments on an 18 segment model of the atria harbouring PDs) with freedom from arrhythmia at 1 year follow up.

RESULTS

Of 100 patients, 97 completed follow up and 52 (53.6%) remained in sinus rhythm off antiarrhythmic drugs. Neither PD burden nor PD distribution predicted freedom from arrhythmia (HR 1.01, 95% CI 0.99 - 1.03, p = 0.164; and HR 1.04, 95% CI 0.91 - 1.17, p = 0.591 respectively). Otherwise, the burden of rotational PDs, rotational stability, and the burden of PDs occurring at the pulmonary veins and posterior wall all failed to predict arrhythmia recurrence (all p > 0.10).

CONCLUSIONS

AF mechanisms as determined using ECGI mapping do not predict outcome after PVI for persistent AF. Further studies using different methodologies to characterise AF mechanisms are warranted. (NCT03394404) This article is protected by copyright. All rights reserved.

Transseptal puncture for left atrial ablation: risk factors for cardiac tamponade and a proposed causative classification system

Aims

Cardiac tamponade is a high morbidity complication of transseptal puncture (TSP). We examined the associations of TSP‐related cardiac tamponade (TRCT) for all patients undergoing left atrial ablation at our center from 2016 to 2020.

Methods and Results

Patient and procedural variables were extracted retrospectively. Cases of cardiac tamponade were scrutinized to adjudicate TSP culpability. Adjusted multivariate analysis examined predictors of TRCT. A total of 3239 consecutive TSPs were performed; cardiac tamponade occurred in 51 patients (incidence: 1.6%) and was adjudicated as TSP‐related in 35 (incidence: 1.1%; 68.6% of all tamponades). Patients of above‐median age [odds ratio (OR): 2.4 (1.19–4.2), p = .006] and those undergoing re‐do procedures [OR: 1.95 (1.29–3.43, p = .042] were at higher risk of TRCT. Of the operator‐dependent variables, choice of transseptal needle (Endrys vs. Brockenbrough, p > .1) or puncture sheath (Swartz vs. Mullins vs. Agilis vs. Vizigo vs. Cryosheath, all p > .1) did not predict TRCT. Adjusting for operator, equipment and demographics, failure to cross the septum first pass increased TRCT risk [OR: 4.42 (2.45–8.2), p = .001], whilst top quartile operator experience [OR: 0.4 (0.17–0.85), p = .002], transoesophageal echocardiogram [TOE prevalence: 26%, OR: 0.51 (0.11–0.94), p = .023], and use of the SafeSept transseptal guidewire [OR: 0.22 (0.08–0.62), p = .001] reduced TRCT risk. An increase in transseptal guidewire use over time (2016: 15.6%, 2020: 60.2%) correlated with an annual reduction in TRCT (R² = 0.72, p < .001) and was associated with a relative risk reduction of 70%.

Conclusions

During left atrial ablation, the risk of TRCT was reduced by operator experience, TOE‐guidance, and use of a transseptal guidewire, and was increased by patient age, re‐do procedures, and failure to cross the septum first pass.

ProGlide venous closure device facilitates early ambulation following cryoablation of atrial fibrillation

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): Heart Foundation

Background

Same-day discharge following atrial fibrillation (AF) ablation is increasingly common. ProGlide device suture-mediated vascular closure (PD) offers a technique that may expedite mobilisation following large-bore (&gt;12F) venous access. The utility of PD closure following cryoablation of AF has not been reported.

Purpose

We sought to evaluate haemostasis and early ambulation outcomes in patients receiving the ProGlide compared with conventional techniques.

Methods

104 consecutive patients undergoing cryoballoon pulmonary vein isolation (PVI) for paroxysmal or persistent at a single high-volume institution were included. PVI was  performed via a standardised approach including sedation, ultrasound-guided vascular access for 14F Cryosheath and second 7F sheath, anticoagulation protocol, transeptal puncture, 28mm cryoballoon and nurse-led same-day discharge protocol. Haemostasis was achieved using the Perclose Proglide device (PD) in the 14F access point ("pre-closure" technique) plus 5 minutes manual pressure at the 7F sheath site. Alternatively, a figure-of-eight/Z-suture (ZS) was employed for closure according to operator preference. Protamine was used for heparin reversal in all patients. Safety outcomes of major bleeding, haematoma and minor bleeding were assessed. Time to ambulation (TTA), time to discharge (TTD), same-day discharge and complications at initial follow-up were measured.

Results

Overall, mean age was 64 ± 11 years, 65 (64%) were male and 52 (50%) of patients had paroxysmal AF, there were no significant differences between group demographics, with 31 patients (30%) in the PD group and 73 (70%) in the ZS group. All patients had uninterrupted oral anticoagulation throughout the periprocedural period. No major femoral bleeding complications requiring intervention occurred in either group. Haematomas occurred in none of the PD group compared with 2 (2.8%) in the ZS group. Incidence of minor bleeding was not significantly different between groups (PD: 3 [9.7%] vs ZS: 2 [2.7%], p = 0.155). Mean TTA was significantly shorter in the PD group (3.3 ± 1.1 vs 4.1 ± 1.7 hrs, p = 0.025). However, there was no significant difference in same-day discharge (PD: 25 [81%] vs ZS: 53 [73%], p = 0.386) and TTD (5.0 ± 3.6 vs 6.1 ± 4.2 hrs, p = 0.275) between groups. 1 patient complained of groin pain which delayed discharge in the ZS group not seen in the PD group. After a mean follow-up of 2.2 ± 1.4 months, there were no differences in major or minor complications.

Conclusion

Use of the Proglide closure device was associated with significant reductions in time to ambulation compared with Z-suture haemostasis following cryoablation of AF, and groin access complications were uncommon across groups.  PD closure may contribute to further streamlining patient pathways in day-case AF ablation.

Long-term outcomes of index cryoballoon ablation or point-by-point radiofrequency ablation in patients with atrial fibrillation and systolic heart failure

Catheter ablation is an established effective approach for the treatment of atrial fibrillation (AF) in patients with heart failure, however, the role of cryoablation in this setting is unclear. Procedural success and left ventricular systolic dysfunction (LVEF) improvement in patients with LVEF ≤ 45% undergoing index catheter ablation with cryoablation were evaluated. Freedom from AF recurrence was seen in 43% rising to 59% following repeat procedure. There were significant improvements in LVEF and functional status at long-term follow-up. Results were comparable to a contemporaneous cohort of heart failure patients undergoing index ablation with radiofrequency ablation. Cryoablation is an effective first-line AF ablation approach in the setting of heart failure.

P6586Brugada syndrome risk stratification - Evaluation of clinical and ECG risk markers in a multicenter international primary prevention cohort

Background

Risk stratification for sudden cardiac death (SCD) in Brugada syndrome (BrS) is a significant challenge.

Purpose

To evaluate the importance of clinical and ECG factors in the likelihood of developing significant ventricular arrhythmias (VAs)/SCD in BrS patients.

Methods

VA occurrence during follow-up were assessed and the role of 16 proposed clinical or ECG risk markers evaluated in a multicenter international study of BrS patients and no history of cardiac arrest. Markers with predictive power were identified and incorporated into a risk score model.

Results

Across 15 international centers, 1084 patients were included. During a follow-up of 5.3 years (IQR 2.7–9.0 years)- 110 patients had VA occurrence (10.1%) with an annual event rate of 1.7% (95% CI 1.4–2.0). Of the 16 proposed risk factors, diagnosis by family screening of sudden cardiac death (HR 4.65; p<0.001), probable arrhythmia related syncope (HR 3.88, p<0.001), type 1 spontaneous ECG (HR 3.56; p<0.001), Early Repolarisation (HR 3.15; p<0.001) and type 1 Brugada pattern in peripheral leads (HR 2.42; p<0.001) were associated with a higher VA occurrence risk during follow-up. These 5 variables were incorporated into a risk score model whereby each variable was allocated a point score based on the variable's predictive strength. The total points obtained from the model for a patient could then be translated into the predicted VA occurrence risk during follow-up (Figure 1). The model showed a sensitivity of 63.5% (95% CI 50.0–76.9) and specificity of 84.2% (95% CI 81.1–87.1) in predicting VA occurrence at 5-years follow-up. The model showed a greater discriminative power compared to an existing model (AUC 0.83 vs. 0.71; p<0.001).

Figure 1

Conclusions

This multicenter study with longest reported follow-up to date identified 5 risk markers for VA occurrence. Utilizing these markers in a risk score model can aid BrS risk stratification to enable individualized risk prediction and ICD prescription.

Assessment of a conduction-repolarisation metric to predict Arrhythmogenesis in right ventricular disorders

BACKGROUND

The re-entry vulnerability index (RVI) is a recently proposed activation-repolarization metric designed to quantify tissue susceptibility to re-entry. This study aimed to test feasibility of an RVI-based algorithm to predict the earliest endocardial activation site of ventricular tachycardia (VT) during electrophysiological studies and occurrence of haemodynamically significant ventricular arrhythmias in follow-up.

METHODS

Patients with Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) (n = 11), Brugada Syndrome (BrS) (n = 13) and focal RV outflow tract VT (n = 9) underwent programmed stimulation with unipolar electrograms recorded from a non-contact array in the RV.

RESULTS

Lowest values of RVI co-localised with VT earliest activation site in ARVC/BrS but not in focal VT. The distance between region of lowest RVI and site of VT earliest site (Dmin) was lower in ARVC/BrS than in focal VT (6.8 ± 6.7 mm vs 26.9 ± 13.3 mm, p = 0.005). ARVC/BrS patients with inducible VT had lower Global-RVI (RVIG) than those who were non-inducible (-54.9 ± 13.0 ms vs -35.9 ± 8.6 ms, p = 0.005) or those with focal VT (-30.6 ± 11.5 ms, p = 0.001). Patients were followed up for 112 ± 19 months. Those with clinical VT events had lower Global-RVI than both ARVC and BrS patients without VT (-54.5 ± 13.5 ms vs -36.2 ± 8.8 ms, p = 0.007) and focal VT patients (-30.6 ± 11.5 ms, p = 0.002).

CONCLUSIONS

RVI reliably identifies the earliest RV endocardial activation site of VT in BrS and ARVC but not focal ventricular arrhythmias and predicts the incidence of haemodynamically significant arrhythmias. Therefore, RVI may be of value in predicting VT exit sites and hence targeting of re-entrant arrhythmias.

Validation of a novel mapping system and utility for mapping complex atrial tachycardias

INTRODUCTION

This study sought to validate a novel wavefront mapping system utilizing whole-chamber basket catheters (CARTOFINDER, Biosense Webster). The system was validated in terms of (1) mapping atrial-paced beats and (2) mapping complex wavefront patterns in atrial tachycardia (AT).

METHODS AND RESULTS

Patients undergoing catheter ablation for AT and persistent AF were included. A 64-pole-basket catheter was used to acquire unipolar signals that were processed by CARTOFINDER mapping system to generate dynamic wavefront propagation maps. The left atrium was paced from four sites to demonstrate focal activation. ATs were mapped with the mechanism confirmed by conventional mapping, entrainment, and response to ablation. Twenty-two patients were included in the study (16 with AT and 6 with AF initially who terminated to AT during ablation). In total, 172 maps were created with the mapping system. It correctly identified atrial-pacing sites in all paced maps. It accurately mapped 9 focal/microreentrant and 18 macroreentrant ATs both in the left and right atrium. A third and fourth observer independently identified the sites of atrial pacing and the AT mechanism from the CARTOFINDER maps, while being blinded to the conventional activation maps.

CONCLUSIONS

This novel mapping system was effectively validated by mapping focal activation patterns from atrial-paced beats. The system was also effective in mapping complex wavefront patterns in a range of ATs in patients with scarred atria. The system may therefore be of practical use in the mapping and ablation of AT and could have potential for mapping wavefront activations in AF.

Safety and efficacy of paramedic treatment of regular supraventricular tachycardia: a randomised controlled trial

INTRODUCTION

Supraventricular tachycardias (SVTs) are a common cause of acute hospital presentations. Adenosine is an effective treatment. To date, no studies have directly compared paramedic-with hospital-delivered treatment of acute SVT with adenosine.

METHOD

Randomised controlled trial comparing the treatment of SVT and discharge by paramedics with conventional emergency department (ED)-based care. Patients were excluded if they had structural heart disease or contraindication to adenosine. Discharge time, follow-up management, costs and patient satisfaction were compared.

RESULTS

Eighty-six patients were enrolled: 44 were randomised to paramedic-delivered adenosine (PARA) and 42 to conventional care (ED). Of the 37 patients in the PARA group given adenosine, the tachycardia was successfully terminated in 81%. There was a 98% correlation between the paramedics' ECG diagnosis and that of two electrophysiologists. No patients had any documented adverse events in either group. The discharge time was lower in the PARA group than in the ED group (125 min (range 55-9513) vs 222 min (range 72-26 153); p=0.01), and this treatment strategy was more cost-effective (£282 vs £423; p=0.01). The majority of patients preferred this management approach. Being treated and discharged by paramedics did not result in the patients being less likely to receive ongoing management of their arrhythmia and cardiology follow-up.

CONCLUSIONS

Patients with SVT can effectively and safely be treated with adenosine delivered by trained paramedics. Implementation of paramedic-delivered acute SVT care has the potential to reduce healthcare costs without compromising patient care.

TRIAL REGISTRATION NUMBER

NCT02216240.

Management of atrial fibrillation: when are invasive approaches useful?

The management of atrial fibrillation extends from stroke prevention to rate or rhythm control strategies. The role of an invasive strategy is expanding and it remains important to identify suitable candidates early in the disease process.