Background: Atrial fibrillation (AF) increases morbidity and mortality in heart failure with preserved ejection fraction (HFpEF), yet identification of HFpEF-patients at risk for new-onset AF is challenging. Amplified P-wave duration (APWD) non-invasively detects arrhythmogenic atrial substrate with high accuracy. We hypothesized that APWD may help in the prediction of new-onset AF in HFpEF.
Methods: Patients with suspected HFpEF (n = 99, left ventricular ejection fraction > 50%, no evidence of valvulopathy, coronary artery disease, or non-cardiac dyspnea) underwent exercise testing with concomitant right-heart catheterization. Normal resting pulmonary capillary wedge pressure (PCWP; < 12 mmHg) with an increase during exercise > 25.5 mmHg/W/kg defined early HFpEF. Advanced HFpEF was diagnosed with PCWP > 12 mmHg at rest. Arrhythmogenic atrial substrate (defined as APWD > 150 ms) was investigated on digitized standard 12-lead ECGs and patients were followed for new-onset AF at 6-month intervals.
Results: Forty-seven patients had normal exercise haemodynamics and served as controls. Early and advanced HFpEF was diagnosed in 29 and 23 patients, respectively. Eighty-seven per cent of patients with advanced HFpEF had evidence of arrhythmogenic atrial substrate, (APWD 175 ± 29 ms vs. 132 ± 14 ms in controls, p < 0.0001), which was associated with a tenfold increased risk for new-onset AF during 4.6 years of follow-up (hazard ratio [HR] 9.684, 95% CI 2.61-35.89, p < 0.0001). Early HFpEF was neither related to APWD (p = 0.395), nor to a higher risk for AF (HR 3.44, 95% CI 0.57-20.72, p = 0.178). Importantly, the presence of arrhythmogenic substrate was independent of left atrial indexed volume.
Conclusion: The analysis of amplified P-wave duration (APWD) allows for the prediction of new-onset AF in patients with advanced HFpEF.
Keywords: Atrial arrhythmia; Atrial fibrillation; Diastolic dysfunction; HFPEF; Heart failure.