Then, LDL-C is calculated by subtracting VLDL-C and HDL-C from total cholesterol. 1 The formula’s core variable is an estimate of very low-density lipoprotein cholesterol (VLDL-C) as the level of triglycerides (in milligrams per deciliter) divided by 5, while the other 2 components, total and high-density lipoprotein cholesterol (HDL-C), are quantitated. The Friedewald formula to estimate low-density lipoprotein cholesterol (LDL-C) levels was derived from 448 normal or hyperlipidemic individuals more than 4 decades ago, before the existence of current LDL-lowering therapies. Trial Registration Identifier: NCT01764633 The Martin/Hopkins method may prevent undertreatment because of LDL-C underestimation by the Friedewald method. The correlation with PUC LDL-C was significantly higher for Martin/Hopkins vs Friedewald (ρ, 0.918 vs ρ, 0.867, P < .001).Ĭonclusions and Relevance In patients achieving low LDL-C with PCSK9 inhibition, the Martin/Hopkins method for LDL-C estimation more closely approximates gold standard PUC than Friedewald estimation does. These were significantly less than respective proportions with Friedewald estimation (40.1% and 13.3% P < .001), mainly because of underestimation by the Friedewald method. Overall, 22.9% of Martin/Hopkins LDL-C values were more than 5 mg/dL different than PUC values, and 2.6% were more than 10 mg/dL different than PUC levels. The median difference from PUC LDL-C levels for Martin/Hopkins LDL-C levels was −2 mg/dL (interquartile range, −4 to 1 mg/dL) and for Friedewald LDL-C levels was −4 mg/dL (IQR, −8 to −1 mg/dL P < .001). A total of 56 624 observations from 12 742 patients had Friedewald, Martin/Hopkins, and PUC LDL-C measurements. Results For this analysis, the mean (SD) age was 62.7 (9.0) years 2885 of the 12 742 patients were women (22.6%). Main Outcomes and Measures Low-density lipoprotein cholesterol calculated by the Friedewald and Martin/Hopkins methods, with PUC as the reference method. In the Martin/Hopkins method, patient-specific ratios of triglycerides to very low-density lipoprotein cholesterol (VLDL-C) ratios were determined and used to estimate VLDL-C, which was subtracted from the non–HDL-C level to obtain the LDL-C level. The patients’ LDL-C levels were assessed at baseline, 4 weeks, 12 weeks, 24 weeks, and every 24 weeks thereafter, and measured directly by PUC when the level was less than 40 mg/dL per the Friedewald method (calculated as non–HDL-C level − triglycerides/5). Objective To investigate accuracy of 2 different methods for estimating LDL-C levels (Martin/Hopkins and Friedewald) compared with gold standard preparative ultracentrifugation (PUC) in patients with low LDL-C levels in the Further Cardiovascular Outcomes Research With PCSK9 Inhibition in Patients With Elevated Risk (FOURIER) trial.ĭesign, Setting, and Participants The FOURIER trial was a randomized clinical trial of evolocumab vs placebo added to statin therapy in 27 564 patients with stable atherosclerotic cardiovascular disease. However, this method has not been tested in proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor–treated patients. A novel method (Martin/Hopkins) using a patient-specific conversion factor provides more accurate LDL-C levels. Importance Recent studies have shown that Friedewald underestimates low-density lipoprotein cholesterol (LDL-C) at lower levels, which could result in undertreatment of high-risk patients. Shared Decision Making and Communication.Scientific Discovery and the Future of Medicine.Health Care Economics, Insurance, Payment.Clinical Implications of Basic Neuroscience.Challenges in Clinical Electrocardiography.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |