Systolic Blood Pressure Visit-to-Visit Variability and Major Adverse Outcomes in Atrial Fibrillation: The AFFIRM Study (Atrial Fibrillation Follow-Up Investigation of Rhythm Management)

Abstract

Hypertension and atrial fibrillation predict major adverse events independently. Visit-to-visit variability (VVV) in systolic blood pressure (SBP) predicts outcomes beyond SBP itself, but risk associated with SBP-VVV in atrial fibrillation remains uncertain. We evaluated relationships between SBP-VVV, quality of oral anticoagulation control, and outcomes in patients with atrial fibrillation. Data from the AFFIRM trial (atrial fibrillation follow-up investigation of rhythm management) were analyzed. SBP-VVV was defined according to SD of SBP (SBP-SD) during follow-up. SBP-VVV was categorized by quartiles (1st, <10.09; 2nd, 10.09-13.85; 3rd, 13.86-17.33; and 4th, ≥17.34 mm Hg) and as a continuous variable. Among the original cohort, 3843 (94.7%) patients were eligible. Time in therapeutic range and percentage of international normalized ratio in range were progressively lower by quartiles (both P<0.001). An inverse linear association existed between SBP-SD and time in therapeutic range/percentage of international normalized ratio in range (P<0.001). After a median (interquartile range) follow-up of 3.6 (2.7-4.6) years, stroke and major bleeding rates progressively increased by SBP-VVV quartile (both P<0.001). Patients in the 4th quartile had the highest rate of cardiovascular and all-cause death (P=0.005 and P<0.001). A Cox multivariate analysis confirmed that 3rd and 4th quartiles were associated independently with a higher risk for stroke (P=0.042 and P=0.004) and major bleeding (P=0.009 and P<0.001). Patients in 4th quartile had also a higher risk for all-cause death (P=0.048). SBP-SD as a continuous variable was associated with increased risk for all outcomes. In conclusion, SBP-VVV is inversely associated with quality of anticoagulation control and independently predicts major adverse outcomes. Management of blood pressure variability may improve outcomes in atrial fibrillation.

Clinical trial registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00000556.

Keywords: anticoagulant drugs; atrial fibrillation; hypertension; major bleeding; outcomes research; stroke.