A post-hoc analysis of the Systolic Blood Pressure Intervention Trial (SPRINT) composed of patients with hypertension at risk for cardiovascular (CV) events showed that levels of low-density lipoprotein cholesterol (LDL-C) do not affect CV event risk over a 3-year period in patients with hypertension. In patients with hypertension with a prior cardiovascular disease (CVD) history excluding stroke, however, LDL-C levels may increase the risk for CV events. Findings from this analysis were published in the International Journal of Cardiology.
Patients included in the SPRINT (N=9361) trial had hypertension and were randomly assigned to either intensive or standard anti-hypertension treatment. At baseline, all patients had ≥1 variable that placed them at an increased risk for CV events, including age >75, history of CVD other than stroke, chronic kidney disease, or 10-year Framingham risk score >15%. The median follow-up was 3.26 years.
The clinical outcomes defined by the post-hoc SPRINT researchers included a composite of various CV outcomes, all-cause mortality, and CV mortality. In the post-hoc analysis, researchers assessed the association between LDL-C and the primary clinical outcome. Analyses were adjusted for age, sex, body mass index, active smoking status, estimated glomerular filtration rate-estimated kidney function, history of CVD, Framingham risk score, SPRINT treatment arm (intensive or control), baseline high-density lipoprotein-bound cholesterol, and co-treatments with aspirin and statins.
In the overall cohort, ≤16.7% of patients had a prior history of CVD. No independent associations were found between LDL-C and the incidence of the primary outcome, according to multivariable Cox regression analyses. In patients with a previous history of CVD excluding stroke (n=1562), the researchers found an association between LDL-C (per 1 mg/dl increase) and the primary outcome (adjusted hazard ratio 1.005; 95% CI, 1.002-1.009; P =.005). This subgroup of patients had lower LDL-C compared with the overall cohort (94.6±35.4 vs 112.1±35.8, respectively; P <.00001).
A limitation of the study included the adjustment of only variables that were available at baseline, which resulted in the potential of unmeasured factors that may have influenced the findings.
These findings support “contemporary recommendations which emphasize secondary prevention with aggressive LDL-C lowering irrespective of baseline levels,” the researchers wrote. “This is even more relevant since the amplitude of risk reduction is proportional to the absolute LDL-C reduction, while LDL-C reduction is proportional to baseline LDL-C.”
Nguyen LS, Procopi N, Salem JE, Squara P, Funck-Brentano C. Relation between baseline LDL-cholesterol and cardiovascular outcomes in high cardiovascular risk hypertensive patients: A post-hoc SPRINT data analysis [published online January 15, 2019]. Int J Cardiol. doi:10.1016/j.ijcard.2019.01.048