1Universitäres Herz- und Gefäßzentrum Hamburg Klinik für Kardiologie Hamburg, Deutschland; 2Universitäres Herz- und Gefäßzentrum Hamburg Klinik für Kardiologie mit Schwerpunkt Elektrophysiologie Hamburg, Deutschland; 3Universitäres Herz- und Gefäßzentrum Hamburg Allgemeine und Interventionelle Kardiologie Hamburg, Deutschland
Introduction
Atrial tachyarrhythmias are primary drivers in the development of arrhythmia-induced cardiomyopathy (AiCM). The restoration of sinus rhythm in patients with an AF (atrial fibrillation) based AiCM results in enhancement of left ventricular ejection fraction (LV-EF). This study aims to assess the prevalence of undiagnosed and unexplained heart failure among patients with AF referred for catheter ablation and seeks to phenotype these patients.
Methods
The TRUST registry, a prospective, observational clinical cohort that recruits patients with heart rhythm disorders at a large tertiary-care center since March 2021 was interrogated for AF patients. These patients underwent screening for heart failure based on clinical, laboratory, and imaging baseline characteristics. Undiagnosed heart failure at baseline, lack of heart failure medication and absence of known structural heart disease were considered suspicious for lone AiCM.
Results
A total of 1225 patients were analyzed. 35.2% were female, median age was 67 (IQR 59;75) years, median LV-EF 55.0 (IQR 50;60) % and median NT-proBNP 686 (IQR 210;1630) mg/dl. NYHA class I was reported in 28.3% cases, NYHA class II in 32.2%, NYHA class III in 20.2% and NYHA class IV in 2%.
At baseline, 263 patients (17.6%) had an ejection fraction < 50%, of those 110/263 (42%) with suspected AiCM. Patients with suspected AiCM were 67 (IQR 58;76) years old, 40.9% were female, median LV-EF was 41.0 (IQR 35;41) % and NT-proBNP at admission was 1681 (IQR 775;2352) mg/dl. Patients with suspected AiCM had a significantly reduced TAPSE (19 vs. 22 mm; p<0.001), showed clinical characteristics of heart failure (NTproBNP: p<0.001, NYHA class: p=0.049), while EHRA score was significantly lower (p=0.006).
In contrast, patients with known cardiomyopathy of non-AiCM origin at baseline and EF < 50% (n=153) had significantly higher LAVI (44.8 vs. 38.8 ml/m2; p=0.002), were predominantly male (76.5 vs. 59.1 %; p=0.004) and had lower GFR (60.2 vs. 68.5 ml/min; p=0.002) compared to AiCM patients.
Among 29/110 suspected AiCM patients with available TTE at follow-up (within 12 months post-catheter ablation), 26/29 exhibited an improved LV-EF (40% at baseline vs. 54% at FU; p<0.001). 3/3 patients without LV-EF improvement exhibited arrhythmia recurrence.
Conclusion
Primary AiCM was suspected in 42% of all AF patients with reduced LV-Function referred for catheter ablation. These patients exhibited distinctive phenotypic characteristics and 90% benefited from catheter ablation in terms of EF improvement. These findings call for structured HF screening in clinical routine in AF patients. In the future, validated scores are required to enable early rhythm control for these patients.Figure 1: proportion of patients with reduced ejection fraction (already diagnosed cardiomyopathy at baseline vs. suspected Arrhythmia-induced Cardiomyopathy (AiCM)) among all patients with atrial fibrillation (AF) referred for catheter ablation.
Figure 2: course of ejection fraction following catheter ablation in patients with suspected Arrhythmia-induced Cardiomyopathy (AiCM).