Thrombolytic therapy impact on prognosis after twelve months of first acute myocardial infarction

Thrombolytic therapy is still widely used to restore antegrade flow in the infarct related artery (IRA), with unquestionable benefits in mortality reduction of such patients. The aim of this study was to evaluate early (< or = 28 days) and one-year mortality of patients with a first Q wave myocardial infarction (Q AMI), comparing those who underwent thrombolytic therapy with those who did not.

A retrospective study was done on 907 patients (median age: 35 +/- 13 years, 66% male) admitted to a Coronary Unit with the diagnosis of first Q AMI, from January 1988 to December 1997, all in the same geographical area (minimum follow-up period of one year, mean follow-up 43 +/- 37 months). We compared demographics and clinical characteristics (coronary risk factors, previous history of angina, MI location and evolution, cardiac events, 28 day and one-year mortality) of patients who underwent thrombolysis (group T = 355) versus those who did not undergo reperfusion therapy (group NT = 552).

Of these patients 39% underwent thrombolytic therapy. Group NT had a greater number of female patients (40% vs 25%; p < 0.001), a significantly higher mean age (67 +/- 12.2 vs 61 +/- 12; p < 0.001), and a higher percentage of diabetics (29% vs 19%; p < 0.001), in comparison to group T. The Q AMI developed into Killip class > or = 2 in 43% of patients in group NT and 23% in group T (p < 0.001). A higher number of AV block (NT-13% vs T-8%; p < 0.05) and higher in-hospital mortality (NT-14% vs T-9%; p < 0.05) was observed in patients not undergoing thrombolysis. The early (NT-22% vs T-12%; p < 0.001) and one-year (NT-33% vs T-16%; p < 0.001) mortalities were significantly higher in group NT than in group T, even after multivariate analysis.

1--Patients who did not undergo thrombolytic therapy initially had a profile of greater severity, and a higher early and one-year mortality rate. 2--Those who underwent thrombolytic therapy presented a significantly lower mortality, a benefit that was still observed after one year of follow-up and after multivariate correction.