Factors Associated With Normal Flow (TIMI 3) After Thrombolysis With Streptokinase in ST-Elevation Myocardial Infarction: A Prospective Observational Study

Background Thrombolysis with streptokinase (STK) is the most widely used reperfusion strategy for ST elevation myocardial infarction (STEMI) in India. Achieving full reperfusion as evidenced by thrombolysis in myocardial infarction (TIMI) flow grade 3 in coronary angiography (CAG) is associated with better outcomes. Recent studies show that hematological indices like neutrophil-lymphocyte ratio (NLR) and mean platelet volume (MPV) estimated before thrombolysis could predict TIMI 3 flow. We studied clinical, electrocardiographic and hematological parameters associated with TIMI 3 flow after thrombolysis with STK. Methods We prospectively studied 201 adult patients with STEMI presenting within 12 hours of onset of chest pain. Before thrombolysis, blood sample was collected for estimating NLR and MPV. Timing of CAG after thrombolysis was decided by consultant cardiologists. Patients were followed up for one month after discharge. Results Of 201 patients, 162 (81%) had relief of chest pain and 131 (65%) had ST segment recovery of ≥50% at 90 minutes after thrombolysis. CAG was performed within median (IQR) of four (3-5) days after thrombolysis. TIMI 3 flow was observed in 112 (56%) patients. NLR and MPV had no significant association with TIMI 3 flow. In multivariable analysis, ST-segment recovery of ≥50% at 90 minutes was associated with TIMI 3 flow (adjusted OR 3.47, 95% CI: 1.84-6.53, P= <0.001). Of 198 patients followed up for one month after discharge, 13 (6.5%) died. Conclusions In patients with STEMI, ST-segment recovery of ≥50% at 90 minutes after thrombolysis with STK predicted TIMI 3 flow independently. NLR and MPV values were not predictive of TIMI 3 flow.