THE IMPACT OF CONTROLLING RISK-FACTORS AFTER MYOCARDIAL-INFARCTION

The relative risks of each factors and the benefits of their reduction after myocardial infarction are comparable to those observed in primary prevention. However; because of an overexposure to the risk, the absolute gains are five times greater. The impact of diet is one of the most important : in addition to the limitation of polyunsaturated fats and global calory intake, especially in cases of central obesity, the increase in dietary alpha-linolenic acid and in omega-3, has been shown to reduce the risk of myocardial infarction and mortality by up to 70 %. Supplements of vitamins A and E could be useful. After infarction, the risks of an ex-smoker decrease rapidly by half and become comparable to those of non-smokers in 2 to 3 years. Physical exercice reduces cardiovascular mortality by 20-25 % and contributes to better control of risk factors. The management of some psycho-physiological factors (reaction to stress, hostility) also gives encouraging results). A 10 % reduction in total cholesterol leads to a 20 % or more decrease in coronary events and a 10 % reduction in mortality with a marked dose-response effect inciting to the reduction of its level to under 2 g/l. The progression of atherosclerosis delayed; early lesions, with the greatest risk of rupture and thrombosis, are stabilised and may even regress. A low HDL-c concentration should lead to more energetic reduction of LDL-c and control of smoking, obesity and sedentarity. Its association with hypertriglyceridaemia, glucose intolerance, hypertension and central obesity defines the syndrome of insulin resistance which multiplies cardiovascular risk. The control of hypertension could reduce the number of recurrences and of coronary mortality by 20 %; betablockers and ACE inhibitors are logical prioritary drugs. The control of diabetes with diet and insulin reduces the incidence of vascular complications. Thrombogenic factors (especially fibrinogen, partially associated with smoking and triglycerides) reinforce the indications of antithrombotic agents. These different approaches in most cases integrate the use of drugs, the prophylactic efficacy of which has been demonstrated : aspirin or vitamin K antagonists, betablockers, ACE inhibitors.