Development and validation of the HARMS2-AF lifestyle risk score to predict incident AF

Background

Lifestyle risk factors (RFs) are a modifiable target in atrial fibrillation (AF) management. However, the relative contribution of individual lifestyle RFs to AF incidence has not been described.

Purpose

Development and validation of a novel AF-lifestyle risk score to determine AF risk in the general population.

Methods

The UK Biobank (UKB) is a large prospective cohort with outcomes measured >10 years. In the UKB, we performed regression analysis of AF lifestyle RFs which were then evaluated in a multivariable model and a weighted score was developed. Next, the risk score was externally validated in the Framingham Heart Study (FHS) population. Kaplan-Meier estimates ascertained the 10-year risk of AF development.

Results

In the UKB, AF incidence was 5.3% among 302,926 participants, with a median time to AF 7.3 years (IQR 4.3–9.8). Hypertension, sleep apnoea, male sex, age, obesity (BMI>30 kg/m2), alcohol and smoking were predictive variables (all p<0.001); physical inactivity (OR 1.02,95% CI 0.97–1.10, p=0.3), diabetes (OR 0.98,95% CI 0.91–1.06, p=0.2) and BMI 27–30 kg/m2 (OR 1.02, 95% CI 0.97–1.07, p=0.424) were not significant. The HARMS2-AF score (Figure 1) had similar predictive performance (AUC=0.782, LogLoss 0.178, Brier Score 0.046) to the unweighted regression model (AUC 0.808) in the UKB. Validation in the FHS (AF incidence 6.7% of 7206 participants) maintained excellent predictive performance with an AUC of 0.747 (95% CI 0.724–0.769, Figure 2). A higher HARMS2-AF score (>5 points) was associated with a heightened 10-year AF risk (score 5–9: OR 9.35, score 10–14: OR 33.34).

Conclusions

The HARMS2-AF score is a novel lifestyle risk score which may help identify individuals at risk of AF and assists in general population screening.

Funding Acknowledgement

Type of funding sources: None.

Clinical risk prediction for left atrial appendage thrombus among patients with atrial fibrillation

Background

Exclusion of left atrial appendage thrombus (LAAT) by transoesophageal echocardiography (TOE) is recommended in patients with inadequate anticoagulation prior to direct cardioversion (DCR) or catheter ablation for atrial fibrillation/flutter (AF/AFL). LAAT risk factors in this population remain poorly defined.

Purpose

Determine LAAT predictors in AF/AFL patients undergoing pre-procedural TOE.

Methods

We evaluated available clinical and transthoracic echocardiographic (TTE) parameters in AF/AFL patients undergoing TOE between 1999–2022 in our institution in Melbourne, Australia. Regression analysis identified predictors of LAAT, which were applied to a weighted score developed in the derivation cohort (70%) and validated in the remaining 30%.

Results

Of 627 patients (age 62±12 years, 27% female, AF 84%,AFL 16%, left ventricular ejection fraction (LVEF) 44±20%), 24% had LAAT and 13.8% dense spontaneous echo contrast precluding DCR. Anticoagulation was NOAC 56.5%, warfarin 32.1% and none in 11.4%. In the LAAT cohort, thrombus resolution occurred in 39% on serial transoesophageal imaging with a median time to resolution of 131 days (IQR 54–398).

Diabetes (p=0.004), prior stroke (p=0.009), coronary disease (p=0.015), renal impairment (p<0.001) and CHADS2VASc >2 (73% vs. 55%, p<0.001) were higher in the LAAT cohort. Age (p=0.093), gender (p=0.689), BMI (p=0.828), anticoagulant type (p=0.316) and diabetes (p=0.107) were not univariate predictors, whereas anticoagulation duration (<30 days), creatinine and TTE markers of remodeling (LVEF, LAVI, RVSP and TAPSE) were independent predictors on univariate and multivariate regression; CHADS2VASc was not significant after adjustment (p=0.090). The weighted risk model included continuous (age, creatinine, LVEF, LAVI, TAPSE and RVSP) and categorical (anticoagulation duration) variables with excellent predictive performance: AUC 0.872 (95% CI 0.798–0.946), PPV 91%, NPV 70% and accuracy 80%.

Conclusion

A novel LAAT risk model comprising clinical and echocardiographic parameters enhances risk prediction over CHADS2VASc in AF/AFL and may guide the need for pre-procedural TOE imaging.

Funding Acknowledgement

Type of funding sources: None.

Long-term implications of pacemaker insertion in younger adults: a single centre experience

Background

The long-term implications of pacemaker insertion in younger adults are poorly described in the literature.

Methods

We performed a retrospective analysis of consecutive younger adult patients (18–50 years) undergoing pacemaker implantation at a quaternary hospital between 1986–2020. Defibrillators and cardiac resynchronisation therapy devices were excluded. All clinical records, pacemaker checks and echocardiograms were reviewed.

Results

81 patients (39.5±9.6 years, 53% male) underwent pacemaker implantation. Indications were complete heart block (41%), sinus node dysfunction (33%), high grade AV block (11%) and tachycardia-bradycardia syndrome (7%). During a median 7.6 (IQR=0.6–14.8) years follow-up, 9 patients (11%) developed 13 late device-related complications (generator or lead malfunction requiring reoperation (n=11), device infection (n=1) and pocket revision (n=1)). Five of these patients were <40 years old at time of pacemaker insertion. At long-term follow-up, a further 9 patients (11%) experienced significant symptoms from inadequate lead performance managed with device reprogramming. Sustained ventricular tachycardia was detected in 2 patients (2%). Deterioration in ventricular function (LVEF decline >10%) was observed in 14 patients (17%) and 7 of these patients required subsequent biventricular upgrade. Furthermore, 4 patients (5%) developed new tricuspid regurgitation (≥ moderate-severe). Of 69 patients with available long-term pacing data, minimal pacemaker utilisation (pacing <5% at all checks) was observed in 13 (19%) patients.

Conclusions

Pacemaker insertion in younger adults has significant long-term implications. Clinicians should carefully consider pacemaker insertion in this cohort given risk of device-related complications, potential for device under-utilisation and issues related to lead longevity. In addition, patients require close follow-up for development of structural abnormalities and arrhythmias.

Funding Acknowledgement

Type of funding sources: None.

Unearthing the evidence: post-mortem interrogation of cardiac implantable electronic devices

Background

The diagnostic yield of post-mortem interrogation of cardiac implantable electronic devices (CIEDs) including pacemakers, defibrillators and implantable loop recorders has not been well described.

Methods

We reviewed all post-mortem CIED interrogations performed by our statewide Institute of Forensic Medicine between 2005–2020 for investigation of sudden or unexplained death.

Results

260 patients (68.8% male, median age 72.8 years [IQR 62.7–82.2]) underwent post-mortem CIED interrogation (202 pacemakers, 56 defibrillators and 2 loop recorders). CIEDs were implanted for a median of 2.0 [IQR 0.75–5] years, with 19 devices requiring replacement (and 5 end of life). Post-mortem interrogation was successful in 256 (98.5%) cases. Potential CIED malfunction was identified in 21 (8.1%) cases: untreated ventricular arrhythmias (n=13), lead failures (n=3) and battery depletion (n=5). CIED interrogation directly informed cause of death in 130 (50.0%) cases, with fatal ventricular arrhythmias identified in 121 patients (46.5%). In retrospect, 72 (27.7%) patients had abnormalities recorded by their device in the 30 days preceding death: non-sustained ventricular tachycardia (n=26), rapid atrial fibrillation (n=17), longevity concerns (n=22), intrathoracic impedance alarms (n=3), lead issues (n=3) or therapy delivered (n=1). In 6 cases where the patient was found deceased after a prolonged time, CIED interrogation accurately determined time of death. In one case, CIED interrogation was the primary method of patient identification.

Conclusion

Post-mortem CIED interrogation frequently contributes important information regarding critical device malfunction, pre-mortem abnormalities, cause and time of death or patient identity. Device interrogation should be considered for select patients with CIEDs undergoing autopsy.

Funding Acknowledgement

Type of funding sources: None.

Impact of catheter ablation on HFpEF in people with comorbid atrial fibrillation and HFpEF using invasive haemodynamic testing

Background

The impact of catheter ablation (CA) for atrial fibrillation (AF) in patients with heart failure with preserved ejection fraction (HFpEF) is unknown.

Objectives

To determine whether CA for AF reverses adverse haemodynamic changes associated with HFpEF.

Methods

Consecutive consenting patients with EF ≥50% scheduled for index CA underwent baseline exercise right heart catheterisation (exRHC), cardiac output (CO) measurement, cardiac MRI, echocardiogram, QOL questionnaires and BNP testing. HFpEF was defined by resting pulmonary capillary wedge pressure (PCWP) ≥15mmHg or peak exercise PCWP ≥25 mmHg during exRHC. Patients with HFpEF were offered follow-up exRHC ≥6 months post-CA.

Results

Of 252 patients scheduled for CA between April 2017 and Sept 2019, 131 (51.9%) qualified for inclusion, 65 (49.6%) consented to exRHC and 11 (16.9%) were excluded due to a subsequent decrease in EF (10) and uncontrolled hypertension (1). Fifty-four underwent exRHC, with 35 (65%) meeting criteria for HFpEF. Of them 26 (74.3%) who underwent CA, 20 (77%) had a follow up exRHC at 12±6 months follow-up, showing an overall decrease in peak exercise PCWP from 30.3±4.2 to 26.8±4.7 mmHg (p<0.05). Patients without arrhythmia recurrence showed significant improvements in peak exercise PCWP (29.2±3.7 to 22.9±2.0 mmHg (p<0.01). Their cardiac output increased from 10.3±3.0 to 12.1±4.0 mmHg p=0.1), and BNP decreased from (94.6±101.6 to 38.0±34.0 mmHg (p=0.06),whereas those with arrhythmia recurrence did not. Overall, 9 patients (45.0%) no longer met criteria for HFpEF.

Conclusion

There is a high prevalence of HFpEF in people referred for AF ablation. Successful CA for AF reverses the adverse haemodynamic changes associated with HFpEF

Changes in PCWP following AF ablation

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): NHMRC, NHF, RACP