Predictors of Failed Thrombolysis in Acute Myocardial Infarction

Background & objectives: Acute myocardial infarction (AMI) is becoming increasingly important problem in developing countries, and thrombolysis is the main modality of treatment here. About 2550% of patients fail to achieve successful reperfusion and these patients have poor prognosis. Since alternative modes of reperfusion are available, it is important to identify them. This study was aimed at defining the extent of failed thrombolysis and identifying its demographic and clinical predictors Methods: 50 cases of thrombolysed AMI patients were studied. Failed thrombolysis considered if there is < 50% resolution of ST-segment elevation after 90minutes of thrombolysis in single lead showing maximum ST elevation at presentation. The clinical predictors of the outcome were assessed. Results: Of 50 patients studied 30(60%) achieved successful thrombolysis and 20(40%) failed. Mean time to thrombolysis from onset of symptom was 5.85 ±2.49 hrs in failed group v/s 4.55 ±2.4hrs in successful group (P<0.05).Mean age was 52.3±11.14yrs v/s 57.4±12.5yrs (P>0.05), percentage of females was 25% v/s 16.7%(P>0.05), mean time for resolution of chest pain was 3.55±1.1 hrs v/s. 1.98±0.93 hrs (P<0.001), percentage of anterior MI was 70% v/s 53% (P>0.05), inferior wall MI was 30% v/s 46% (P>0.05) in failed and successful group respectively. Interpretation and conclusion: Late presentation is an important risk factor for failed thrombolysis in AMI. Persistence of chest pain and non-resolution of reciprocal ST depression are significantly associated with failed thrombolysis