Am Fam Physician. 2005;71(7):1416-1418
Statins have demonstrated efficacy in primary and secondary prevention of coronary artery disease. Although these benefits have been attributed to lipid-lowering effects, statins may decrease negative outcomes by other effects such as modulation of inflammation, inhibition of platelet function and thrombosis, and improvement of endothelial function. Data from the Platelet Receptor Inhibition for Ischemic Syndrome Management (PRISM) trial demonstrated better short-term outcomes in patients with acute coronary syndrome who were already taking statins than in those who were not. Spencer and associates reviewed data from a large multinational observation study that compared outcomes in patients with acute coronary syndromes who used statins or received in-hospital statin treatment with patients who did not use statins.
Patients were entered into the Global Registry of Acute Coronary Events (GRACE) study based on an initial diagnosis of acute coronary syndromes and were followed for final diagnosis and outcomes. Previous statin use was defined as taking statins on a long-term basis and within seven days of the acute event precipitating hospitalization. In-hospital treatment with statins was defined as initiating statin therapy during hospitalization, and statin use at discharge was defined as initiating statin therapy after discharge.
Patients who already were taking statins were more likely than the other groups to have hyperlipidemia, hypertension, vascular disease, or diabetes, and were slightly less ill at the time of hospitalization. These patients were much less likely to have a final diagnosis of myocardial infarction and were less likely to die during hospitalization or develop other selected clinical complications. Patients who had used statins previously and continued taking them in the hospital had better outcomes than patients who had never taken statins. Initiation of statin therapy during hospitalization in statin-naïve patients resulted in decreased mortality rates and decreased development of serious cardiac complications compared with patients who never received statin therapy.
The authors conclude that previous or early use of statin therapy improves in-hospital outcomes in patients admitted for acute coronary syndromes. Pretreated patients were less likely to present with ST-segment elevation or have a large infarct. These benefits probably are related to effects other than lipid-lowering. This positive effect was less apparent if statin treatment was not continued in the hospital. Statin withdrawal may result in a rebound effect that causes plaque destabilization and increased endothelial dysfunction.
In an editorial in the same journal, Laupacis and Mamdani note that observational studies remain useful for real-life pattern analyses, but these studies are problematic because of survivor treatment selection bias and competing medical issues. Although statins have been documented in other studies to be useful in patients at high risk of acute coronary syndrome, the usefulness of early initiation of statin therapy during hospitalization remains less certain.
editor’s note: The most recent guidelines offered by the National Cholesterol Education Program reflect additional knowledge from recent clinical trials with statin therapy and clinical end points. Several changes in cholesterol management have been recommended, including (1) persons at very high risk should have a low-density lipoprotein (LDL) cholesterol goal of < 70 mg per dL (1.80 mmol per L). This can be achieved with medication, if necessary; (2) for high-risk patients with low high-density lipoprotein (HDL) cholesterol or high triglyceride levels, a fibrate or nicotinic acid can be added to the lipid-lowering regimen; (3) for moderately high-risk patients (i.e., those with two or more risk factors), an LDL cholesterol goal of < 100 mg per L (2.60 mmol per L) is recommended; (4) lifestyle intervention is appropriate for all patients in the very high-risk or moderately high-risk groups; (5) lipid-lowering therapy should be sufficient to achieve a 30 to 40 percent reduction in LDL cholesterol levels; and (6) the goals of therapy remain unchanged from previous recommendations for patients in lower-risk categories.1 Issues about very low LDL cholesterol levels continue to be investigated, and physicians can treat patients as mentioned above or base therapy on patient risk and medication efficacy, safety, and cost.1—r.s.