Abstract
Introduction
The preventive effect of lipid lowering treatment in secondary prevention after coronary heart disease (CHD) is well documented. In 2015, regional guidelines recommend an LDL cholesterol of ≤1.8 mmol/L for patients with established CHD but the adherence to these guidelines is low.
Purpose
Our aim was to predict potential reductions in cardiovascular disease (CVD) events defined as acute myocardial infarction or stroke if patients: 1) with low-dose/less potent or no statin were treated with Atorvastatin 80 mg, or 2) all reached LDL ≤1.8 mmol/L.
Methods
In total, 37 120 patients with established CHD in a primary care regional register 2015 were studied. Predicted number of CVD events were calculated with actual treatment, with improved treatment and with lowered LDL. For risk estimation we used data from a Cox Proportional Hazards risk estimation model based on patients from 2010 (n=52 042) in combination with data from the literature on effect of statin treatment and LDL reduction. A risk reduction of 22% for CVD events per 1 mmol/L reduction in LDL was used in our model.
The risk prediction model included age, sex, diabetes mellitus, a history of heart failure and/or atrial fibrillations, treatment with acetylic salicylic acid and stroke or AMI past year. Smoking and BMI were excluded due to missing data but sensitivity analysis has shown only small differences in results.
Results
In total, 18% of included patients reached LDL ≤1.8 mmol/L and 32% had no statin treatment. Based on actual LDL levels and treatments, the predicted number of CVD events over 5 years was 9209/37120. If all patients with no statin or less potent statin treatment had been given atorvastatin 80 mg this would lead to a reduction of CVD events by 14% (7901 vs 9209). The largest gain, 33% reduction, occurred when adding statins to patients without previous treatment (1970 vs 2937). Furthermore, if all patients were to reach LDL ≤1.8 mmol/L the predicted number of events would be reduced by 18% (7577 vs 9209).
Conclusion
There is a substantial potential to reduce the number of CVD events in the large population of patients with established CHD in primary care by improved adherence to lipid treatment guidelines.
Acknowledgement/Funding
Närhälsan R&D Health Care, R&D Centre Gothenburg and Södra Bohuslän. the Swedish state under the Agreement concerning research and education of doctor