Usefulness of novel Martin/Hopkins and Sampson equations over Friedewald equation in cardiology outpatients: A CVSCORE-TR substudy.

Abstract

The Friedewald equation (LDL-Cf) is known to produce inaccurate estimations of low-density lipoprotein cholesterol (LDL-C) when triglycerides are high (>400mg/dL) or LDL-C is low (<70mg/dL). The Martin/Hopkins (LDL-Cmh) and Sampson (LDL-Cs) equations were developed to overcome these limitations, but few data are available to assess whether these equations offer incremental usefulness over LDL-Cf. Our aim was to understand whether there was any incremental usefulness of novel equations on decisions regarding patient management. Four thousand one hundred and ninety-six cardiology patients who were included in a multicentre registry database were analysed. Each patient was assigned to a cardiovascular risk class using the SCORE (Systematic COronary Risk Evaluation) algorithm, and relevant European guidelines were used to assess LDL-C targets. Compared with LDL-Cmh and LDL-Cs, LDL-Cf was able to correctly identify 96.9%-98.08% of patients as within or outside the LDL-C target, respectively, and 1.95%-2.8% of patients were falsely identified as being within the LDL-C target. Kappa coefficients for agreement between LDL-Cf vs LDL-Cmh and LDL-Cf vs LDL-Cs were 0.868 and 0.918 (P<.001). For patients not on cholesterol-lowering drugs, the decision to initiate treatment would be different in 1.2%-1.8% of cases if LDL-Cs or LDL-Cmh were used, respectively. For those already on cholesterol-lowering drugs, decisions regarding treatment intensification would be different in 1.5%-2.4% of cases if LDL-Cs or LDL-Cmh were used. In most cardiology outpatients, the Friedewald equation has excellent agreement with the novel Martin/Hopkins and Sampson equations, and treatment decisions should not change in most patients.