An LDL cholesterol (LDLc) under 70 mg/dl is recommended for all patients with ischemic heart disease. The publication of new trials showing reduction in major adverse cardiac events in the last years have spread the idea that "the lower the better" when treating LDLc. Even so, recent observational studies in different countries in Europe have shown a little prevalence of appropriate LDLc control.
The purpose of our study is to evaluate, in real life, the LDLc control in an ambulatory very high risk population, as well as the variation from 2013 and 2018, presumably influenced by scientific literature. We also aim to determine which clinical variables contribute to a worse LDLc control.
We selected all consecutive patients visited from the June 2014 to July 2016 in Cardiology ambulatory visits diagnosed with myocardial infarction and three LDLc determinations in 2013, 2016 and 2018 and basic demographic variables were collected. For every year, LDLc means were obtained and predictors of attaining an LDLc lower than 70 mg/dl were assessed. We evaluated the variation of LDLc between 2013 and 2018 an the percentage of people with LDLc lower than 70 mg/dl.
We identified 805 patients with myocardial infarction diagnosis and all three LDL measurements. Only 21,6% patients in 2013 had an LDLc<70 mg/dl, and this number increased up to 33,8% in 2018. Only 9,1% of the population had all three LDLc measurements under 70 mg/dl, and 48,4% of them had none of the measurements in the optimal range. Male sex (p<0,05) and diabetes mellitus (p<0,05) were both predictors of attaining an LDLc<70 mg/dl in both years. There was a significant mean LDLc reduction from 2013 to 2018 (p<0,001), with a mean LDLc of 95,79 +- 34,05 mg/dl in 2013 and a mean of 83,69 +- 29,45 mg/dl in 2018. The more recent the year of the first myocardial infarction was, the bigger the LDLc reduction was in these years.
LDLc under 70 mg/dl in a very high risk population is attained only in a small fraction of the entire population, being our data consistent with existing registries. Even so, a reduction in LDLc has been observed, possibly attributable to the impact of recent literature, but the fact that only 9,1% of the patients had all three LDLc measurements under 70mg/dl probably indicates that medical treatment is diminished in these patients. Since no differences in LDLc reduction has been observed between subgroups in clinical trials, further studies should investigate why this consistent subgroup effect depending on sex and diabetes is observed, and if it may be due to different risk perceived by the physician. By analysing actual LDLc control, our study identifies some shortcomings in LDLc management in a very high risk population and offers the opportunity to solve them.