Antihypertensive control and new-onset atrial fibrillation: Results from the Swedish Primary Care Cardiovascular Database (SPCCD)

Background: Atrial fibrillation is associated with increased cardiovascular morbidity and mortality. Hypertension is an important risk factor for the development of atrial fibrillation. Aim: This study assessed the relationship between blood pressure control and new-onset atrial fibrillation in hypertensive patients. Methods and results: We followed 45,530 hypertensive patients with no previously documented atrial fibrillation, attending primary healthcare in Sweden during 2001-2008. After a mean follow-up of 3.5 years 2057 patients (4.5%) developed atrial fibrillation. Compared to patients with no atrial fibrillation, the new-onset atrial fibrillation group (after adjustment for age, sex, diabetes mellitus, heart failure, ischaemic heart disease, cerebrovascular disease and number of visits) had higher mean in-treatment systolic blood pressure (SBP) and diastolic blood pressure of 3.8mmHg (95% confidence interval (CI) 3.0-4.6; P < 0.0001) and 1.6mmHg (95% CI 1.2-2.0; P<0.0001), respectively. Similarly, mean in-treatment pulse pressure in the new-onset atrial fibrillation group was 2.2mmHg (95% CI 1.6-2.9; P < 0.001) higher. In a logistic regression analysis, achieved SBP140mmHg was associated with a higher risk of new-onset atrial fibrillation, compared to SBP 130-139mmHg (odds ratio (OR) 1.5; 95% CI 1.3-1.7) and to SBP < 130mmHg (OR 1.3; 95% CI 1.1-1.5). There was no difference in risk for new-onset AF between SBP 130-139 and < 130mmHg (OR 0.9; 95% CI 0.7-1.1). Conclusion: The present findings indicate that blood pressure control in hypertension is associated with a lower risk of new-onset atrial fibrillation.