Electrocardiographic spatial QRS-T angle and incident cardiovascular disease in hiv-infected patients (from the Strategies for the Management of Antiretroviral Therapy [SMART] Study)

Widening of the electrocardiographic (ECG) spatial QRS-T angle has been predictive of cardiovascular disease (CVD) events in the general population. However, its prognostic significance in human immunodeficiency virus (HIV)-infected patients remains unknown. The spatial QRS-T angle was derived from the baseline resting 12-lead electrocardiogram of 4,453 HIV-infected patients aged 43.5 ± 9.3 years from the Strategies for Management of Antiretroviral Therapy (SMART) trial. CVD events were identified during a median follow-up of 28.7 months. Quartiles of the spatial QRS-T angle was calculated for men and women separately, and values in the upper quartile were considered as a widened angle (values >74° for women and >93° for men). A multivariate Cox proportional hazards analysis was used to examine the association between a widened baseline spatial QRS-T angle and incident CVD events. During 11,965 person-years of follow-up, 152 CVD events occurred at a rate of 1.27 events/100 person-years. The rate of CVD events in those with a widened spatial QRS-T angle was almost double the rate in those with a normal spatial QRS-T angle (rate ratio 1.94, 95% confidence interval 1.40 to 2.69; p <0.001). In a model adjusted for study treatment arm, demographics, CVD risk factors, HIV characteristics, inflammatory markers, and other ECG abnormalities, a widened spatial QRS-T angle was associated with a >50% increased risk of CVD events compared to a normal spatial QRS-T angle (hazard ratio 1.53, 95% confidence interval 1.07 to 2.17; p = 0.02). No interaction was seen by SMART trial arm (p value for interaction = 0.37) or gender (p value for interaction = 0.84). In conclusion, a widened spatial QRS-T angle was independently predictive of CVD events in HIV-infected patients receiving antiretroviral therapy. This highlights the potential role of routine electrocardiography as a simple noninvasive CVD risk-screening tool in HIV-infected patients.