P-358: Are doctors and patients using statins effectively for the prevention of coronary heart disease?

Abstract

The aim of this study was to determine whether HMG-CoA reductase inhibitors (statins) are used in line with current recommendations for the prevention of coronary heart disease and to identify factors which determine patient response.

Patients attending the Cardiovascular Risk Clinic in Aberdeen were prospectively screened for statin use. Gender, age, current statin and dose, treatment start date, pre- and most recent post-treatment lipid measurements were recorded.

407 patients receiving a statin were identified of whom 355 had a complete lipid data set. 194 (54.6%) failed to meet the recommended total cholesterol (TC) target of <5.0mmol/l. Failure to meet target levels was associated with a significantly higher pre-treatment TC (7.66±1.37 vs 6.61±1.13mmol/l, p<0.001), statin treatment for primary prevention (47.9% vs 34.8%, p<0.05), and a significant increase in length of time since the last lipid measurement (13.00±9.36 vs 11.05±8.03 months, p<0.05). Although the average duration of treatment was greater for the failed group (32.7±20.0 vs 27.7±15.0 months, p<0.05), 71.1% of patients had not had a serum lipid estimation within the preceding 6 months and 40.6% within the preceding year. Despite similar levels of statin usage in both groups (21.1±10.1 vs 19.4±7.8mg/day of simvastatin, failed vs met, p=0.086) patients in the failed group had a significantly lower response to statin therapy (21.34±12.80% vs 32.45±12.10, p<0.001) indicating poor patient compliance or the existence of a group of poor responders. To identify factors other than pre-treatment TC which might explain treatment failure, 116 patients were matched for pre-treatment TC (58 met, 58 failed) and data analysed. The only significant difference between these two groups was the response to statin therapy, which was greater in those who had met target (33.6±7.6% vs 14.1±9.0%, p<0.001).

At the present time we are failing to meet recommended cholesterol targets. The reasons for this are evident from the low doses of statin prescribed (mean 20.15±8.82mg/day), and failure to measure response appropriately. Pre-treatment TC should determine the starting statin dose which then should be up-titrated according to response. There are also a group of individuals who have a poor response to statin therapy regardless of pre-treatment TC raising the possibility of poor compliance. Although statins may be used in appropriate patients they are not used to achieve optimal CHD risk reduction indicating the need for further doctor and patient education.

HMG-CoA Reductase Inhibitors, Efficacy, Poor Responders