215 - Impact of LDL formula and apo B quantification on UK PCSK9i and ESC/EAS treatment thresholds in patients being investigated for familial combined hyperlipidaemia (ID 285)
Abstract
Background and Aims
Low-density lipoprotein cholesterol ( LDL-C) reduction remains crucial for managing cardiovascular disease risk and informs treatment targets. Friedewald LDL is the mainstay of UK practice. Claculated LDL-C using the new Martin's formula and apo B were compared to Friedewald to determine the impact on PCSK9i eligibility and risk classification.
Methods
Laboratory systems were searched over 14 months for patients with lipid profile and triglycerides < 4.5 mmol/L who were being investigated for familial combined hyperlipidaemia (FCH) with an apoB. LDL-C was calculated using Friedewald (LDL-F) and Martin equations (LDL-M). Values were compared to each other, apo B, treatment and risk thresholds.
Results
In 49 patients LDL-M, correlated well with LDL-F, but was consistently higher (mean 0.42 mmol/L). If LDL-M is used instead of LDL-F, 4% of patients would move from having LDL-C < 3.5 mmol/L to > 3.5, 8% <4 to >4 and 12% <5 to >5. The effect of changing formula was larger at higher LDL-C. The 2 patients with LDL-C <1.8 mmol/L ( both formula) also had an apo B <0.65 g/L. If using EAS risk thresholds for treatment escalation more people were treated well according to apo B than LDL (10 <1g/L compared to 2 <1.8 mmol/L).
Conclusions
Martin equation provides a greater estimation of LDL-C. Using LDL-M could result in increasing the number of patients eligible for PCSK9i therapy at most by 12% according to UK thresholds. Apo B demonstrated the converse, i.e.better apo B reduction than LDL however this may reflect the population ( suspected FCH).
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