RESUMEN
Reinfarction occurs in approximately 10-20% of patients with acute myocardial infarction with an year incidence of about 3% for males and 9% for females. The reinfarction induces a worsen prognosis by producing arrhythmias and a new ventricular "remodelling" with an increase in sudden death and cardiogenic shock. The new event may occur, early or later, in regions either adjacent to or remote from the initial myocardial infarction. Among all the patients admitted to our coronary care unit (1181) during the last 6 years, the overall reinfarction rate was 11.4%; among these, 46% were in the same side (SSMI), while 54% in the distant side (DSMI). The SSMI occurred more often during early months after infarction, while the DSMI occurred significantly later. Cigarettes smoking has been shown to be a common and often the only risk factor in patients with early reinfarction; while arterial hypertension, mostly associated with diabetes and hypercholesterolemia, was found the most important risk factor in later reinfarctions. SSMI was strongly related to one coronary vessel disease or to a double vessel disease (especially with interventricular artery and right coronary artery); while DSMI occurred in presence of triple coronary vessel disease involving secondary branches. The later SSMI is related to serious impairment of left ventricular function in 30% of patients, with cardiogenic shock and death evolution in 25%. The clinical trials for prevention of reinfarction showed that the correction of risk factors and the use of anticoagulation and/or antiaggregation therapy, beta-blockers or Ca(++)-antagonist drugs, must be chosen in relation to the myocardial damage related to previous infarct. In all the patients follow-up during the acute, subacute and chronic phases, must be performed by clinical and instrumental controls able to evidence the developing new cardiovascular events in order to decision making.