Objective: High serum cholesterol is one of the major risk factors for coronary heart disease (CHD). RESULTS from large clinical trials have convincingly shown the importance of cholesterol lowering therapy among patients with established CHD. Revised guidelines for cholesterol lowering therapy were published in Iceland in 1996 recommending reduction of total cholesterol below 5.0 mmol/L in the face of established coronary heart disease. We have today very limited knowledge about whether we are implementing these recommendations or not and the aim of this study was to evaluate this question. This study is a part of a larger enquiry into the actual practice of secondary prevention of CHD in Iceland.
Material and methods: All patients with residence in Hafnarfjörethur, Garethabaer and Bessastaethahreppur who have been diagnosed as having CHD were sent a letter with an invitation to participate in the study and a request for an informed consent. Those who chose to participate responded to a questionnaire and gave a permission for a review of their records with respect to a specific diagnosis and lipid values. The patients were divided into four groups on the basis of their history: I. myocardial infarction (MI), II. coro notnary artery bypass surgery (CABG), III. percuta notneous transiluminal coronary angioplasty (PTCA), IV. angina pectoris (AP). If a patient fulfilled a cri notterion for more than one diagnostic group the CABG group had the highest priority followed by PTCA, MI and finally AP.
Results: Of 533 patients with CHD 402 (75%) chose to participate. Average cholesterol in the total group was 6.2 mmol/L (95% C.I. 6.07-6.34). In the four subgroups the respective cholesterol values were: I 6.3, II 5.9, III 5.9, IV 6.5 mmol/L. Only 25% of the patients knew their cholesterol values, 20% in group I, 43% in group II, 30% and 15% in groups III and IV respectively. A total of 113 patients (28%) were receiving cholesterol lowering drug therapy at the time of the study. Respective treatment ratios in the four subgroups were 25% in group I, 47% in II, 42% in III and 13% in group IV.
Conclusions: In spite of overwhelming evidence of the benefit associated with lipid lowering therapy for CHD patients this study has shown marked underuse of this therapeutic modality. Quality control study as this one is a valuable method to evaluate how practising physicians are implementing recommendations, based on scientific evidence, given by health authorities.