LDL-cholesterol change and goal attainment following statin intensity titration among Asians in primary care: a retrospective cohort study

Abstract

Background: Clinical trials have demonstrated that either initiating or up-titrating a statin dose substantially reduce Low-Density Lipoprotein-Cholesterol (LDL-C) levels. However, statin adherence in actual practice tends to be suboptimal, leading to diminished effectiveness. This study aims to use real-world data to determine the effect on LDL-C levels and LDL-C goal attainment rates, when selected statins are titrated in Asian patients.

Methods: A retrospective cohort study over a 5-year period, from April 2014 to March 2019 was conducted on a cohort of multi-ethnic adult Asian patients with clinical diagnosis of Dyslipidaemia in a primary care clinic in Singapore. The statins were classified into low-intensity (LI), moderate-intensity (MI) and high-intensity (HI) groups according to the 2018 American College of Cardiology and American Heart Association (ACC/AHA) Blood Cholesterol Guidelines. Patients were grouped into "No statin", "Non-titrators" and "Titrators" cohorts based on prescribing patterns. For the "Titrators" cohort, the mean percentage change in LDL-C and absolute change in LDL-C goal attainment rates were computed for each permutation of statin intensity titration.

Results: Among the cohort of 11,499 patients, with a total of 266,762 visits, there were 1962 pairs of LDL-C values associated with a statin titration. Initiation of LI, MI and HI statin resulted in a lowering of LDL-C by 21.6% (95%CI = 18.9-24.3%), 28.9% (95%CI = 25.0-32.7%) and 25.2% (95%CI = 12.8-37.7%) respectively. These were comparatively lower than results from clinical trials (30 to 63%). The change of LDL-C levels due to up-titration, down-titration, and discontinuation were - 12.4% to - 28.9%, + 13.2% to + 24.6%, and + 18.1% to + 32.1% respectively. The improvement in LDL-C goal attainment ranged from 26.5% to 47.1% when statin intensity was up-titrated.

Conclusion: In this study based on real-world data of Asian patients in primary care, it was shown that although statin titration substantially affected LDL-C levels and LDL-C goal attainment rates, the magnitude was lower than results reported from clinical trials. These results should be taken into consideration and provide further insight to clinicians when making statin adjustment recommendations in order to achieve LDL-C targets in clinical practice, particularly for Asian populations.

Keywords: Asian; Goal attainment; LDL-cholesterol; Percentage change; Primary care; Real-world data; Statin.

Fig. 1

This figure illustrates the data processing to identify LDL-C pairs for patients in “Titrators” group. To obtain the LDL-C value before statin intensity change (pre_LDL) and after statin change (post_LDL) for the analysis, a statin intensity change is first identified. In the figure, two statin intensity changes (C1 and C2) were identified for the patient (P01). For each statin intensity change, the pre_LDL is taken to be the most recent LDL-C result within one year before a statin intensity titration, while the post_LDL is the first LDL-C value within six weeks to one year after the statin intensity titration. Abbreviations: C1 first statin intensity change, C2 second statin intensity change, P01 illustrative patient, pre_LDL LDL-C before statin intensity titration, post_LDL LDL-C after the statin intensity titration

Fig. 2

Flow chart illustrating the derivation of the patient cohorts. Abbreviation: n number of patients, m number of LDL-C pairs