DEGREE OF RESIDUAL STENOSIS OF THE INFARCT-RELATED ARTERY - ANOTHER VARIABLE AFFECTING RECOVERY OF REGIONAL FUNCTION AFTER THROMBOLYSIS

Aims The aim of this study was to analyse the relationship between inf arct-related artery residual stenosis, assessed by quantitative corona ry angiography, and left ventricular function changes during the in-ho spital period in patients with acute myocardial infarction undergoing thrombolytic treatment. Methods and Results The study population consi sted of 90 patients with acute myocardial infarction treated with thro mbolysis within 6h of the onset of symptoms. Left ventricular function was serially assessed by an echocardiographic asynergy score (before thrombolysis and pre-discharge). Left ventricular end-diastolic and en d-systolic volumes were also calculated. Coronary stenosis was evaluat ed by computer-assisted videodensitometric analysis at pre-discharge c oronary angiography. Three subgroups were identified on the basis of l eft ventricular function changes: 25 patients (Group A) with regional myocardial improvement (echo score from 7.5 +/- 3.5 to 43 +/- 32), 51 (Group B) with no variation in echo score (4.8 +/- 2.7) and 14 (Group C) with myocardial regional worsening (echo score from 4.4 +/- 2.1 to 8.8 +/- 2.4). Group A patients exhibited a very high incidence of infa rct-related artery patency (23/25 patients, 92%) vs 71% with unchanged (Group B) and 14% (Group C) with worsening regional left ventricular function (P<0.001). Subdivision of the study population on the basis o f residual stenosis severity showed that a significant improvement in left ventricular function was present only in the subgroup with residu al stenosis <75% (echo score from 5.2 +/- 3.4 to 3.6 +/- 2.9, P<0.001) . Conclusion These results support the important role exerted by compl ete coronary patency after thrombolysis in inducing left ventricular f unction recovery, and the poor functional improvement in patients with incomplete coronary patency.