Sinus Node Dysfunction is Associated with Higher Symptom Burden and Increased Comorbid Illness: Results from the ORBIT-AF Registry

Background Patients with sinus node dysfunction (SND) have increased risk of atrial tachyarrhythmias, including atrial fibrillation (AF). To date, treatment patterns and outcomes of patients with SND and AF have not been well described. Hypothesis Patients with SND and AF have higher risk of adverse cardiovascular outcomes. Methods Sinus node dysfunction was defined clinically, based on treating physician. Treatment patterns were described and logistic regression analysis performed to assess outcomes. Results Overall, 1710 (17.7%) out of 9631 patients had SND at enrollment. Patients with SND and AF had increased comorbid medical illnesses, more severe symptoms (European Heart Rhythm Association class IV: 17.5% vs 13.9%; P = 0.0007), and poorer quality of life (median 12-month Atrial Fibrillation Effect on Quality of Life score: 79.6 vs 85.2; P = 0.0008). There were no differences in AF management strategy between patients with SND and those without (rate control, 69.7% vs 67.7%; rhythm control, 30.0% vs 32.0%; P = 0.11). After adjustment, patients with SND were more likely than those without SND to progress from paroxysmal AF at baseline to persistent or permanent AF at any follow-up, or persistent AF at baseline to permanent AF at any follow-up (odds ratio: 1.23, 95% confidence interval: 1.01-1.49, P = 0.035). However, there was no association between SND and major risk-adjusted outcomes. Conclusions Sinus node dysfunction is present in 1 of 6 patients with AF and is associated with increased comorbidities and higher symptom burden. However, SND is not associated with an increase in major risk-adjusted outcomes.