Duy Le, MD
Park et al evaluate whether markers outside of LDL alone have any predictive value for secondary prevention of stroke. They evaluate ratios of TG/HDL, TC/HDL, LDL/HDL. Data was reviewed from the Vitamin Intervention for stroke Prevention (VISP) trial. The VISP trial was a multicenter, double blinded, randomized control trial performed in 2004 at centers across the US, Canada and Scotland which enrolled 3680 patients to determine whether high doses of multivitamin given to lower homocysteine levels would reduce the risk of recurrent stroke and major vascular events in non-cardioembolic ischemic stroke. Primary results from this study showed that folate supplementation for elevated homocysteine levels did not change outcomes in terms of recurrent stroke. In this study, serum lipid levels were obtained after an overnight 12 hour fast and at 6,12 and 24 month visits. Park et al tap into this data set. Patient’s data were pulled from their last follow up visit which was defined by the last documented study encounter that preceded either a vascular outcome event or end of trial. Primary outcome was ischemic stroke. Secondary outcome was a composite of stroke, CHD, MI or vascular death.
Each lipid variable was divided into quintiles. A hazard ratio for vascular events by increasing strata was calculated. In the end, when comparing the top quintile to the bottom quintile, the only category which had a p value of significance for both the primary and secondary outcome was the triglyceride/HDL ratio.
Taken altogether, there is suggestion that elevated TG/HDL ratios may be of prognostic value for identifying subjects at risk of a secondary stroke. Prior populations studies have shown no relation between TG/HDL ratios and an increased risk of stroke. However the population evaluated from that study was a mixed patient population. From a secondary standpoint however, TG/HDL may have significance. If this finding is true, then there may be a role of adding a fibrate on to standard statin therapy to decrease the risk of a secondary stroke. Evaluation of this theory would include a double blinded randomized controlled trial with statin vs statin + fibrate and evaluating stroke as a primary outcome and TG/HDL ratios as a secondary outcome.