Impact of atrial fibrillation on the symptoms and echocardiographic evaluation of patients with aortic valve stenosis

Abstract

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): Aarne Koskelo foundation and Helsinki University Hospital EVO funding Introduction Atrial fibrillation (AF) is common among patients with aortic valve stenosis (AS) and can cause similar symptoms. AF may also contribute to diastolic dysfunction. Since AF may alter the echocardiographic profile and provoke symptoms independent of AS, it may complicate the evaluation of AS severity and decision of the time for valve intervention. The purpose of this study was to assess the effect of AF on symptoms and the echocardiographic evaluation of AS. Methods We followed 192 patients (46% female) with suspected severe symptomatic AS who were referred to our institution for intervention. Echocardiography and symptom questionnaires were performed at baseline and 3 months after the intervention. Aortic valve calcium score was measured using computed tomography in the 121 patients considered for transcatheter intervention (TAVR). Results 52 of the 192 patients (27%) had AF. Patients with AF were older (median 81.5 [IQR 74.5-86.3] vs. 74 [64.0-81.3] years) and more often underwent TAVR (81% vs. 54%). In patients with AF the aortic valve mean pressure gradient was lower (39.5 [31.8-48.3] mmHg) than in patients without AF (46 [39.8-52.3] mmHg, p = 0.006, Fig.1A) and a low-gradient phenotype was more common (50% vs. 25% had mean gradient < 40 mmHg). There were no significant differences between groups in AVA, median EF or the proportion of patients with EF <50% (27% vs 17%). The aortic valve calcium score was similar in patients with or without AF (Fig.1B) and, based on the calcium score, 86% (AF) vs. 88% (no AF) of the patients were classified likely or very likely to have severe AS. AF patients had more advanced diastolic dysfunction as demonstrated by higher average E/e’ ratio (15.5 [12.9-20.2] vs. 12.4 [9.90-14.0], p <0.001), left atrial volume index (55.3 [42.0-62.7] vs. 36.7 [32.4-48.7] ml/m2, p <0.001) and tricuspid regurgitation gradient (35.0 [29.0-43.0 vs. 25.0 [23.0-29.0] mmHg, p <0.001). AF patients had worse functional class at baseline (49% vs. 27% with NYHA III or higher, p = 0.01, Fig.2A). There was significant improvement in both groups on follow-up (71% vs 72% improved at least one class), with no difference between groups. Dyspnoea, chest pain and exercise intolerance were equally frequent in patients with and without AF (Fig.2B). After intervention symptoms decreased significantly in both groups. Only exercise intolerance remained more common among AF patients (35% vs. 17%, p = 0.01). Conclusions AS patients with AF present more often with low-gradient phenotype and diastolic dysfunction, which may hamper the evaluation of AS severity. However, calcium score can serve as an alternative tool in the assessment of AS severity particularly in patients with AF and low gradient. Patients with AF are more symptomatic at baseline, but their symptoms improve significantly after intervention and nearly as well as in those without AF. Multiple imaging tools may be needed in decision-making in these patients. Abstract Figure 1 Abstract Figure 2