What are the associations of traditional risk factors and longitudinal measures of human immunodeficiency virus (HIV) disease severity with risk of incident atrial fibrillation (AF) in a contemporary cohort of HIV-infected individuals?
The investigators studied a national sample of 30,533 HIV-infected veterans followed in the Veterans Affairs HIV Clinical Case Registry from 1996-2011. They examined the independent associations of demographic characteristics, time-updated comorbidities, and time-updated clinical measurements including CD4+ cell count and viral load with the outcome of incident AF using proportional-hazards regression for multivariable analysis. Estimates of relative risk were obtained using a time-to-event analysis with multivariable Cox proportional-hazards regression models including demographic and traditional risk factors, as well as markers of HIV severity (CD4+ cell count and viral load).
Over a median follow-up of 6.8 years, 780 (2.6%) patients developed AF. After multivariable
adjustment for traditional risk factors, a lower CD4+ cell count (<200 compared with >350
; hazard ratio [HR], 1.4; 95% confidence interval [CI], 1.1-1.8; p = 0.018) and higher viral load (>100,000 compared with <500 copies/ml; HR, 1.7; 95% CI, 1.2-2.4; p = 0.002) were independently associated with increased risk of incident AF. Additional risk factors independently associated with risk of AF included older age, White race, coronary artery disease, congestive heart failure, alcoholism, proteinuria, reduced kidney function, and hypothyroidism.
The authors concluded that in a large HIV-infected cohort, markers of HIV disease severity
were independently associated with development of AF.
This large, national sample of HIV-infected veterans suggests a significant and graded association between markers of HIV severity and incident AF. Importantly, both a lower CD4+ cell count and a higher viral load provided complementary and independent prognostic information, with an overall pattern of worsened HIV disease severity corresponding with an increased risk of incident AF. These findings suggest a potential biologic link between HIV infection and risk of incident AF that needs further study.
Debabrata Mukherjee, MD, F.A.C.C. (Disclosure)
Arrhythmias, Cardiac Rhythm Management, Afib, Prevention/Vascular