Unanswered questions in including HDL-cholesterol in the cardiovascular risk estimation. Is time still on our side?

Estimation of cardiovascular risk based on total cholesterol versus total cholesterol/high-density lipoprotein within different ethnic groups: The HELIUS study

Aims

European guidelines recommend estimating cardiovascular disease risk using the Systematic COronary Risk Evaluation (SCORE) algorithm. Two versions of SCORE are available: one based on the total cholesterol/high-density lipoprotein cholesterol ratio, and one based on total cholesterol alone. Cardiovascular risk classification between the two algorithms may differ, particularly among ethnic minority groups with a lipid profile different from the ethnic majority groups among whom the SCORE algorithms were validated. Thus in this study we determined whether discrepancies in cardiovascular risk classification between the two SCORE algorithms are more common in ethnic minority groups relative to the Dutch.

Methods

Using HELIUS study data (Amsterdam, The Netherlands), we obtained data from 7572 participants without self-reported prior cardiovascular disease of Dutch, South-Asian Surinamese, African Surinamese, Ghanaian, Turkish and Moroccan ethnic origin. For both SCORE algorithms, cardiovascular risk was estimated and used to categorise participants as low (<1%), medium (1–5%), high (5–10%) or very high (≥10%) risk. Odds of differential cardiovascular risk classification were determined by logistic regression analyses.

Results

The percentage of participants classified differently between the algorithms ranged from 8.7% to 12.4% among ethnic minority men versus 11.4% among Dutch men, and from 1.9% to 5.5% among ethnic minority women versus 6.2% among Dutch women. Relative to the Dutch, only Turkish and Moroccan women showed significantly different (lower) odds of differential cardiovascular risk classification.

Conclusion

We found no indication that discrepancies in cardiovascular risk classification between the two SCORE algorithms are consistently more common in ethnic minority groups than among ethnic majority groups.

Prevalence and treatment of atherogenic dyslipidemia in the primary prevention of cardiovascular disease in Europe: EURIKA, a cross-sectional observational study

Background

Atherogenic dyslipidemia is associated with poor cardiovascular outcomes, yet markers of this condition are often ignored in clinical practice. Here, we address a clear evidence gap by assessing the prevalence and treatment of two markers of atherogenic dyslipidemia: elevated triglyceride levels and low levels of high-density lipoprotein cholesterol.

Methods

This cross-sectional observational study assessed the prevalence of two atherogenic dyslipidemia markers, high triglyceride levels and low high-density lipoprotein cholesterol levels, in the study population from the European Study on Cardiovascular Risk Prevention and Management in Usual Daily Practice (EURIKA; N = 7641; of whom 51.6% were female and 95.6% were White/Caucasian). The EURIKA population included European patients, aged at least 50 years with at least one cardiovascular risk factor but no history of cardiovascular disease.

Results

Over 20% of patients from the EURIKA population have either triglyceride or high-density lipoprotein cholesterol levels characteristic of atherogenic dyslipidemia. Furthermore, the proportions of patients with one of these markers were higher in subpopulations with type 2 diabetes mellitus or those already calculated to be at high risk of cardiovascular disease. Approximately 55% of the EURIKA population who have markers of atherogenic dyslipidemia are not receiving lipid-lowering therapy.

Conclusions

A considerable proportion of patients with at least one major cardiovascular risk factor in the primary cardiovascular disease prevention setting have markers of atherogenic dyslipidemia. The majority of these patients are not receiving optimal treatment, as specified in international guidelines, and thus their risk of developing cardiovascular disease is possibly underestimated.

Trial registration

The present study is registered with ClinicalTrials.gov (ID: NCT00882336).

Electronic supplementary material

The online version of this article (doi:10.1186/s12872-017-0591-5) contains supplementary material, which is available to authorized users.

The high-density lipoprotein-adjusted SCORE model worsens SCORE-based risk classification in a contemporary population of 30,824 Europeans: the Copenhagen General Population Study

Aims

Recent European guidelines recommend to include high-density lipoprotein (HDL) cholesterol in risk assessment for primary prevention of cardiovascular disease (CVD), using a SCORE-based risk model (SCORE-HDL). We compared the predictive performance of SCORE-HDL with SCORE in an independent, contemporary, ‘low-risk’ European population, focusing on ability to identify those in need of intensified CVD prevention.

Methods and results

Between 2003 and 2008, 46 092 individuals without CVD, diabetes, or statin use were enrolled in the Copenhagen General Population Study (CGPS). During a mean of 6.8 years of follow-up, 339 individuals died of CVD. In the SCORE target population (age 40–65; n = 30 824), fewer individuals were at baseline categorized as high risk (≥5% 10-year risk of fatal CVD) using SCORE-HDL compared with SCORE (10 vs. 17% in men, 1 vs. 3% in women). SCORE-HDL did not improve discrimination of future fatal CVD, compared with SCORE, but decreased the detection rate (sensitivity) of the 5% high-risk threshold from 42 to 26%, yielding a negative net reclassification index (NRI) of −12%. Importantly, using SCORE-HDL, the sensitivity was zero among women. Both SCORE and SCORE-HDL overestimated risk of fatal CVD. In well-calibrated models developed from the CGPS, HDL did not improve discrimination or NRI. Lowering the decision threshold from 5 to 1% led to progressive gain in NRI for both CVD mortality and morbidity.

Conclusion

SCORE-HDL did not improve discrimination compared with SCORE, but deteriorated risk classification based on NRI. Future guidelines should consider lower decision thresholds and prioritize CVD morbidity and people above age 65.

High density lipoproteins: Measurement techniques and potential biomarkers of cardiovascular risk

Plasma high density lipoprotein cholesterol (HDL) comprises a heterogeneous family of lipoprotein species, differing in surface charge, size and lipid and protein compositions. While HDL cholesterol (C) mass is a strong, graded and coherent biomarker of cardiovascular risk, genetic and clinical trial data suggest that the simple measurement of HDL-C may not be causal in preventing atherosclerosis nor reflect HDL functionality. Indeed, the measurement of HDL-C may be a biomarker of cardiovascular health. To assess the issue of HDL function as a potential therapeutic target, robust and simple analytical methods are required. The complex pleiotropic effects of HDL make the development of a single measurement challenging. Development of laboratory assays that accurately HDL function must be developed validated and brought to high-throughput for clinical purposes. This review discusses the limitations of current laboratory technologies for methods that separate and quantify HDL and potential application to predict CVD, with an emphasis on emergent approaches as potential biomarkers in clinical practice.