Use of Different Scores for Cardiovascular Risk Stratification in Primary Prevention and Their Implications in Statin Indication

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Abstract

Background: Our setting lacks a cardiovascular risk score arising from a local epidemiological study, and so scores developed from great epidemiological studies in other regions are used. However, although these scores are very useful in clinical practice, they have limitations associated to calibration and discrimination capacity.
Objectives: The purpose of this study was to 1) to stratify cardiovascular risk in a primary prevention population using different scores; 2) to estimate the concordance between these scores; 3) to analyze statin use recommendations; and 4) to estimate the prevalence of carotid atherosclerotic plaque (CAP) and the optimal cut-off point (OCP) of the new American score (NS) to discriminate between subjects with or without CAP.
Methods: Primary prevention patients without diabetes or lipid-lowering therapy were included in the study. The Framingham score (FS), the European score (ES), the score recommended by the World Health Organization (WHOS) and the NS proposed by the new American guidelines were calculated, analyzing the concordance among them. The indication of statins was based on each score. Ultrasound was used to assess CAP occurrence. A ROC analysis was performed to analyze results.
Results: The study included 772 patients. Mean age was 52 ± 11 years and 66% were women. According to FS, ES and WHOS, 78.8%, 50.9% and 91.7% of the population were respectively classified at “low risk”. A poor level of agreement between scores was found (kappa 0.14). The percentage of cases with absolute indication for statins based on FS, ES and NS was 23.6%, 7% and 33%, respectively. When there was no such indication and using the same scores, 23.5%, 50% and 18% of subjects had an optional recommendation. Applying WHOS, only 3% of patients would have been treated. The prevalence of CAP was greater in higher risk strata, though not negligible in low risk subjects. The OCP for NS was 5.2%.
Conclusions: Risk stratification and the use of statins vary according to the cardiovascular score used. Knowledge of the relationship between presence of CAP and scores could improve the estimation of risk in our population.