Detection of familial hypercholesterolemia in patients from a general practice database

Abstract

Objectives: Familial hypercholesterolemia (FH) is the most common monogenic lipid disorder associated with premature coronary heart disease. Early cholesterol-lowering therapy could effectively reduce cardiovascular disease morbidity and mortality in these patients. However, the majority of people with FH are undiagnosed, also due to low awareness and knowledge of FH in general practice, despite the high number of contacts GPs have with most of their patients which allows a systematic and effective approach to the detection of this condition. Here, we present a simple method to improve detection and to enhance awareness of FH in primary care using GP electronic health records.

Methods: We used electronic data from the Co.S. Consortium, involving more than 600 Italian affiliated GPs. Electronic data include demographic information, laboratory test results, recorded history of vascular disease and prescription of an HMG-CoA reductase inhibitor class medication. We performed a partial assessment of the Dutch Lipid Clinic Network (DLCN) score using those data that were recorded or available. We also sought to determine the prevalence of possible FH based on age-specific LDL-cholesterol thresholds employed by the diagnostic criteria of MEDPED and the non-age adjusted cut-off point (LDL-C ≥190 mg/dL).

Results: Data on LDL-C were available for 162,864 subjects. Mean LDL-C levels (SD) were 124.3 (33.6) mg/dL for non-treated subjects and 106.4 (38.5) mg/dL for statin-treated subjects. The cut-off of LDL-C ≥190 mg/dL yielded a prevalence of 2.9% among non-treated subjects and of 3.5% among statin-treated patients. Using the cut-off of ≥250 mg/dL, the prevalence was 0.1% among non-treated subjects and 0.3% among statin-treated patients. Using the cut-off ≥330 mg/dL (suggesting a probable diagnosis of FH according to the DLCN score) the prevalence was 0.01% and 0.02%. According to the stratification proposed by MEDPED criteria for the general population, the age-specific LDL-cholesterol thresholds identified 0.7% among non-treated subjects and 18.5% among statin-treated patients.

Conclusion: The diagnosis of FH is possible in general medicine and should be an integral part of the GP's activity.

Keywords: Cardiovascular diseases; Familial hypercholesterolemia; Primary healthcare.