GENERAL CARDIOLOGY

TNT post hoc analysis highlights importance of HDL

A post hoc analysis of the Treating to New Targets (TNT) study looked specifically at the benefit of raising high-density lipoprotein (HDL) cholesterol in the setting of very low LDL. The original trial had demonstrated the benefits of giving high-dose atorvastatin treatment to lower LDL cholesterol below 100 mg/dl (2.6 mmol/l) in patients with stable coronary artery disease. This analysis looked at 9770 subjects from the trial who were stratified into quintiles based on their HDL cholesterol levels after 3 months of the double-blind treatment phase. A Cox regression model analysis was used to determine the expected 5-year risk of a first major adverse cardiac event (MACE) from non-parametric survivor function estimates determined by quintile of HDL cholesterol.

The HDL cholesterol level in patients receiving statins was predictive of major adverse events across the TNT study cohort, both when HDL cholesterol was considered as a continuous variable and also when stratified according to quintiles of HDL cholesterol. When the analysis was stratified according to LDL cholesterol level, the relationship between HDL cholesterol and major adverse events was of borderline significance (p = 0.05). However, in those with LDL cholesterol levels <70 mg/dl (1.8 mmol/l), patients in the highest quintile of HDL cholesterol were at less risk for MACE than those in the lowest quintile (p = 0.03).

This analysis again confirms that a low HDL level is a powerful predictor of cardiovascular risk. In particular, the data suggest that in patients with known coronary heart disease, higher HDL cholesterol levels may offset the increased risk associated with raised levels of LDL cholesterol. The quintile analysis demonstrates that even among those with very low levels of LDL cholesterol, the risk of a MACE was reduced with higher HDL levels.

▸ Barter P, Gotto AM, LaRosa JC, et al. HDL cholesterol, very low levels of …