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Context: Patients experience the highest rate of death and recurrent ischemic events during the early period after an acute coronary syndrome, but it is not known whether early initiation of treatment with a statin can reduce the occurrence of these early events.Objective: To determine whether treatment with atorvastatin, 80 mg/d, initiated 24 to 96 hours after an acute coronary syndrome, reduces death and nonfatal ischemic events.Design and Setting: A randomized, double-blind trial conducted from May 1997 to September 1999, with follow-up through 16 weeks at 122 clinical centers in Europe, North America, South Africa, and Australasia.Patients: A total of 3086 adults aged 18 years or older with unstable angina or non-Q-wave acute myocardial infarction.Interventions: Patients were stratified by center and randomly assigned to receive treatment with atorvastatin (80 mg/d) or matching placebo between 24 and 96 hours after hospital admission.Main Outcome Measures: Primary end point event defined as death, nonfatal acute myocardial infarction, cardiac arrest with resuscitation, or recurrent symptomatic myocardial ischemia with objective evidence and requiring emergency rehospitalization.Results: A primary end point event occurred in 228 patients (14.8%) in the atorvastatin group and 269 patients (17.4%) in the placebo group (relative risk [RR], 0.84; 95% confidence interval [CI], 0.70-1.00; P =.048). There were no significant differences in risk of death, nonfatal myocardial infarction, or cardiac arrest between the atorvastatin group and the placebo group, although the atorvastatin group had a lower risk of symptomatic ischemia with objective evidence and requiring emergency rehospitalization (6.2% vs 8.4%; RR, 0.74; 95% CI, 0.57-0.95; P =.02). Likewise, there were no significant differences between the atorvastatin group and the placebo group in the incidence of secondary outcomes of coronary revascularization procedures, worsening heart failure, or worsening angina, although there were fewer strokes in the atorvastatin group than in the placebo group (12 vs 24 events; P =.045). In the atorvastatin group, mean low-density lipoprotein cholesterol level declined from 124 mg/dL (3.2 mmol/L) to 72 mg/dL (1.9 mmol/L). Abnormal liver transaminases (>3 times upper limit of normal) were more common in the atorvastatin group than in the placebo group (2.5% vs 0.6%; P<.001).Conclusion: For patients with acute coronary syndrome, lipid-lowering therapy with atorvastatin, 80 mg/d, reduces recurrent ischemic events in the first 16 weeks, mostly recurrent symptomatic ischemia requiring rehospitalization. [ABSTRACT FROM AUTHOR]

Plasma free fatty acids (non-esterified fatty acids) increase in the first hour of the onset of acute myocardial ischaemia. This results from catecholamine stimulation of adipose tissue lipolysis. It can lead to a metabolic crisis in the injured myocardium with the development of ventricular arrhythmias and increased early mortality. Preconditioning, β-adrenergic blockade and glucose-insulin-potassium are possible therapeutic approaches, but anti-lipolytic agents, such as some nicotinic acid derivatives, can reduce plasma free fatty acid concentrations within minutes and have untried potential. A clinical trial of their effectiveness is needed from the first moment when a patient with an acute coronary syndrome is seen by paramedics.

During the onset of an acute coronary syndrome, an immediate increase in plasma free fatty acid (FFA) concentrations presents the ischaemic underperfused myocardium with a metabolic challenge to its survival. For the maintenance of contraction and to counter ventricular arrhythmias, parenteral treatment to reduce FFA availability should be available for paramedics when the patient is first seen. The best treatment options are insulin which partly inhibits FFA release from adipose tissue, immediate reduction of adipose tissue lipolysis, perhaps by new analogues of nicotinic acid, or measures to decrease the FFA/molar binding ratio with albumin. None has yet been tested in appropriate clinical trials.

Evidence that an excess of plasma free fatty acids (FFA) might lead to primary ventricular fibrillation and sudden cardiac death has hardened over the 36 years since the hypothesis was proposed. When the sympathetic nervous system is stimulated during the onset of an acute coronary syndrome, catecholamine-induced tissue lipolysis occurs, with a surge of plasma FFA. This may overload the acutely ischaemic myocardium and impair glucose utilization. Myocardial oxygen consumption can increase in regional areas of ischaemia, and could lead to abnormal electrophysiological conduction and refractoriness, with irreversible ventricular arrhythmias. Efforts to combat the adverse effects of excess FFA include beta-blockade, increasing glucose availability and extraction, or inhibition of lipolysis. This last approach appears promising, but no method has yet been clearly shown to prevent primary ventricular fibrillation or sudden cardiac death. The hypothesis remains viable. More research is needed to derive treatment that can be applied as soon as the onset of acute myocardial ischaemia is suspected.

Aims: Patients with acute coronary syndrome (ACS) in the Myocardial Ischaemia Reduction with Aggressive Cholesterol Lowering (MIRACL) study had diminished cardiovascular events after 16 weeks of treatment of atorvastatin 80 mg daily. We determined whether plasma lipoproteins at baseline and then at 6 weeks after randomization predicted clinical outcome., Methods and Results: Cox proportional hazards models were constructed to determine relations between lipoproteins and clinical endpoint events. Baseline LDL cholesterol (LDL-C) did not predict outcome. In contrast, baseline HDL-C predicted outcome with a hazard ratio of 0.986 per mg/dL increment in HDL-C, P<0.001, indicating 1.4% reduction in risk for each 1 mg/dL increase in HDL-C. Atorvastatin treatment profoundly lowered LDL-C, but had minimal effect on HDL-C. Neither Week 6 LDL-C nor absolute change of LDL-C from baseline by Week 6 had any significant impact on clinical endpoints occurring between Week 6 and Week 16 after randomization., Conclusion: Plasma HDL-C, but not LDL-C, measured in the initial stage of ACS predicts the risk of recurrent cardiovascular events over the ensuing 16 weeks. LDL-C reduction does not account for the clinical risk reduction with atorvastatin treatment after ACS. This finding may suggest that the clinical benefit of atorvastatin after ACS is mediated by qualitative changes in the LDL particle and/or by non-lipid (pleiotropic) effects of the drug.

Background: This report describes the effect of intensive cholesterol lowering with atorvastatin on the incidence of nonfatal stroke, a secondary end point, in a randomized, placebo-controlled trial of patients with unstable angina or non-Q-wave myocardial infarction. The primary end point, a composite of death, nonfatal myocardial infarction, resuscitated cardiac arrest, or recurrent symptomatic myocardial ischemia with objective evidence requiring emergency rehospitalization, was reduced from 17.4% in the placebo group to 14.8% in the atorvastatin group over the 16 weeks of the trial (P=0.048)., Methods and Results: Strokes were adjudicated by a blinded end-point committee using standard clinical and imaging criteria. The outcomes of nonfatal stroke and fatal plus nonfatal stroke were analyzed by time to first occurrence during the 16-week trial. Of 38 events (in 36 patients) adjudicated as fatal or nonfatal strokes, 3 were classified as hemorrhagic, one as embolic, and 29 as thrombotic or embolic; 5 could not be categorized. Nonfatal stroke occurred in 9 patients in the atorvastatin group and 22 in the placebo group (relative risk, 0.40; 95% confidence intervals, 0.19 to 0.88; P=0.02). Fatal or nonfatal stroke occurred in 12 atorvastatin patients and 24 placebo patients (relative risk, 0.49; 95% confidence intervals, 0.24 to 0.98; P=0.04). All 3 hemorrhagic strokes occurred in the placebo group., Conclusion: Intensive cholesterol lowering with atorvastatin over 16 weeks in patients with acute coronary syndromes reduced the overall stroke rate by half and did not cause hemorrhagic stroke. These findings need to be confirmed in future trials.

The mechanisms leading to ventricular fibrillation that occur during acute myocardial ischemia are ill understood. Whether primary ventricular fibrillation is due to a transient imbalance of electrolytes, an alteration of membrane permeability, electrical re-entry phenomena, or other factors, one overriding influence is the development of regional myocardial energy crises. Acute alteration in the balance of substrate supply may lead, during greatly reduced blood flow, to instability of myocardial electrical conduction with the development of re-entry circuits. An immediate response to the angor animi and initial symptoms of an acute coronary syndrome is a rapid and marked increase in catecholamine release, which leads to adipose tissue lipolysis with an acute increase in plasma free fatty acid concentrations, suppression of insulin activity, and a reduction in glucose uptake by the myocardium. The utilization of free fatty acids instead of glucose by the ischemic myocardium could precipitate regional oxygen or energy crises. Prevention therefore should focus on minimizing the catecholamine response and providing the myocardium with an optimum supply of energy substrates. Since catecholamines are inotropic, the aim should be to redress the imbalance of substrate availability by controlling adipose lipolysis with reduction of plasma free fatty acid concentrations, increasing the availability of glucose, or both. Other approaches include inhibition of acylcarnitine transport and manipulation of fatty acid intermediaries. To combat primary ventricular fibrillation, preventive treatment must be established within 6 to 10 hours of the onset of ischemia. There is already experimental and clinical evidence that antilipolytic drugs decrease the incidence of ventricular fibrillation, but their potential has not been explored extensively.