Number of comorbidities is associated with symptom severity and arrhythmia progression in paroxysmal atrial fibrillation - Data from the RACE V study

FUNDING ACKNOWLEDGEMENTS: Type of funding sources: Public grant(s) – National budget only. Main funding source(s): We acknowledge the support from the Netherlands Cardiovascular Research Initiative: an initiative with support of the Dutch Heart Foundation, CVON 2014-9: Reappraisal of Atrial Fibrillation: interaction between hyperCoagulability, Electrical remodelling, and Vascular destabilisation in the progression of AF (RACE V). Unrestricted grant support from Medtronic Trading NL B.V. BACKGROUND: Atrial fibrillation (AF) progression is associated with morbidity and mortality. Both comorbidities and symptom severity are pillars in the ABC treatment pathway as proposed by the ESC guidelines. Interaction between comorbidities, symptom severity and AF progression seems evident, but evidence is lacking. AIMS: The aim of the present study is to investigate whether the number of comorbidities is related with severity of AF symptoms, and whether AF symptom severity is associated with AF progression in patients with paroxysmal AF. METHODS: Patients Underwent extensive phenotyping at baseline and received continuous rhythm monitoring with an implantable loop recorder during follow-up. We studied the relation between comorbidities, AF symptom severity [quantified with the Toronto AF Severity Scale (AFSS)], and AF progression in patients with paroxysmal AF included in the RACE V study. Multivariate regression analysis was performed to study the association between comorbidities and AFSS tertiles, and the association between AF progression and AFSS tertiles. RESULTS: Of 417 paroxysmal AF patients, AFSS questionnaires at baseline were available in 403 patients (97%). Mean age was 65 (IQR 58-71) years, 174 (43%) were women. 132 patients (33%) reported a low score [score 0–2; lowest tertile (T1)], 129 patients (32%) reported a moderate score [score 3–7; middle tertile (T2)], and 142 (35%) reported a high score [score 8–35; highest tertile (T3)]. Patients with the most severe symptoms were older, more often women, more often had coronary artery disease, kidney dysfunction, and a higher body mass index (BMI). The number of comorbidities [defined as hypertension, heart failure, age >65 years, diabetes mellitus; coronary artery disease, BMI >25kg/m2, moderate or severe mitral valve regurgitation and kidney dysfunction (estimated glomerular rate (eGFR) <60)] was a significant determinant of higher AFSS scores [2 (1-3) in T1, 2 (2-3) in T2, 3 (2-4) in T3, respectively P <0.001], with a coefficient of 1.417 (P <0.001) for each extra comorbidity. AF progression occurred most frequently in T3 of the AFSS [10 (7%) in T1, 19 (15%) in T2, 21 (15%) in T3, respectively, P = 0.01]. After adjusting the AFSS tertile for age, coronary artery disease, BMI and eGFR there was no significant association for AFSS with AF progression, AFSS T2 versus T1 OR 2.19 (CI 0.92 - 5.63, P = 0.087), and AFSS T3 versus T1 OR 2.23 (CI 0.92 - 5.84, P = 0.085). AF progression occurred in 14% of AF patients with multimorbidity, defined as ≥2 comorbidities, in comparison to 5% in the AF patients with ≤1 comorbidity (P = 0.023) CONCLUSIONS: In paroxysmal AF, multimorbidity was associated with symptom severity and AF progression. However, symptom severity was not associated with AF progression. [Figure: see text] [Figure: see text]