Abstract 3669: Systolic Blood Pressure is a Better Predictor of Incident Atrial Fibrillation than Pulse Pressure in Healthy Women
Background Recent data suggest that pulse pressure (PP) may be a stronger risk factor than systolic blood pressure (SBP) for the development of atrial fibrillation (AF) in a middle-aged to elderly cohort. However, these associations may differ for younger individuals or women.
Methods We sought to determine the impact of SBP, diastolic blood pressure (DBP), and PP on the risk of incident AF in a prospective cohort of 38,204 apparently healthy women enrolled in the Women’s Health Study. Women included in this analysis were free of cardiovascular disease and AF at study entry and provided complete information on baseline SBP and DBP. SBP and DBP were self-reported by the female health professionals, a group where self-report of BP has proven highly accurate. PP was calculated as the difference between SBP and DBP. The primary endpoint was time to first occurrence of self-reported AF. We constructed Cox proportional hazards models to evaluate the association of SBP, DBP and PP with incident AF, after adjustment for age and other potential confounders.
Results Mean age and body mass index at baseline were 55 ± 7 years and 26.0 ± 5.1 kg/m2, respectively. Mean SBP, DBP and PP were 122 ± 16, 77 ± 10 mmHg and 46 ± 12 mmHg, respectively. During 10.2 years of follow-up, 1009 women (2.6%) reported a new diagnosis of AF. All BP measurements were directly related to risk of AF in age-adjusted and multivariable adjusted models. After multivariable adjustment, the HR (95% CI) for incident AF per 10-mmHg increase in SBP, DBP and PP were 1.08 (1.03–1.13), 1.08 (1.01–1.16) and 1.08 (1.02–1.14). Model fit for the SBP model did not improve by adding DBP or PP to the model (p=ns by likelihood ratio test). Furthermore, when DBP or PP were added separately to the multivariable SBP model, neither added parameter was significant (HR (95% CI) 1.00 (0.92–1.10) and 1.00 (0.91–1.09), respectively). SBP remained a significant predictor of AF in both models (HR (95% CI) 1.08 (1.02–1.14) and 1.08 (1.01–1.16)).
Conclusion In this large prospective study of apparently healthy middle-aged women, SBP was a strong and independent predictor of incident AF. Neither PP nor DBP significantly added to risk prediction in this population.