SBP variability is associated with clinical outcomes in atrial fibrillation patients
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)Literature - Proietti M, Romiti GF, Olshansky B, et al. - Hypertension 2017, published online ahead of print
SBP-VVV and quality of anticoagulation control
- The final adjusted linear regression model found that SBP-SD was inversely associated with TTR (standardized beta: -0.073; t: -4.142; P<0.001), and with PINRR (standardized beta: -0.070; t: -3.959; P<0.001).
- In the final logistic regression model, compared with patients in the 1stQ, those in the 4thQ had a significant inverse association with TTR >70% (OR: 0.75; 95% CI: 0.61–0.92), whereas patients in the 3rdQ and 4thQ were significantly associated with TTR ≤65% (P=0.014 for the 3rdQ and P<0.001 for the 4thQ), and with TTR ≤60% (both P<0.001).
- Continuous SBP-SD was inversely associated with TTR >70% (OR: 0.98; 95% CI: 0.96–0.99 per mm Hg) and directly associated with TTR ≤65% and TTR ≤60% (both P<0.001). Similar results were found for PINRR.
Follow-Up and Survival Analysis
- According to SBP-SD Qs, the rates of stroke and major bleeding progressively increased from the 1stQ to the 4thQ (both P<0.001). Patients in the 3rdQ and the 4thQ had the highest rate for CV death (P=0.005) and all-cause death (P<0.001).
- The composite outcome of stroke/major bleeding/CV death progressively increased from the 1stQ (10.8%) to 4thQ (20.8%; P<0.001).
- According to the Kaplan–Meier curves, patients in the 3rdQ and the 4thQ had a progressively higher risk of stroke (log-rank: 20.024; P<0.001), major bleeding (log-rank: 48.322; P<0.001), and CV death (log-rank: 11.985; P=0.007).
- Patients in the 4thQ had the highest risk for all-cause death (log-rank: 21.333; P<0.001). Patients in the 3rdQ and the 4thQ had the highest risk for the composite outcome (log-rank: 49.929; P<0.001).
- A final forward Cox multivariate regression analysis confirmed that patients in the 3rdQ and 4thQ had an independently increased risk for stroke (HR: 1.85; 95% CI: 1.02–3.35 and HR: 2.33; 95% CI: 1.30–4.16, respectively), and major bleeding (HR: 1.92; 95% CI: 1.18–3.15 and HR: 2.88; 95% CI: 1.79–4.61, respectively). SBP-SD as a continuous variable was associated with an increased risk for both outcomes (P=0.002 for stroke and P<0.001 for major bleeding).
- Despite an increase in risk of CV death for SBP-SD as a continuous variable (P=0.010), SBP-SD Qs were not independently associated with CV death. However, patients in 4thQ had an independent increase in risk for all-cause death (HR: 1.38; 95% CI: 1.00–1.91), which was also evident for SBP-SD as a continuous variable (P<0.001).
In the AFFIRM study, SBP-VVV was inversely associated with the quality of anticoagulation control in AF patients, and increasing SBP-VVV was associated with a higher risk of major adverse clinical events. These results suggest that reducing SBP-VVV and improving the quality of anticoagulation control might be of benefit for AF patients.