The relation between ST-segment resolution and in-hospital mortality after primary percutaneous coronary interventions

Objective: The resolution of ST-segment elevation (>50%) indicates successful reperfusion with thrombolytic therapy. The aim of this study is to evaluate the relation of ST-segment resolution post-primary percutaneous cardiac intervention (PCI) with in-hospital mortality and coronary thrombolysis in myocardial infarction (TIMI) blood flow. Methods: This study is a single-centred retrospective study. The study enrolled 100 patients who were referred to the Nasiriya Heart Centre for primary PCI. We measured the ST segment amplitude in the lead with the highest elevation prior to primary PCI and assessed the ST-segment elevation post-primary PCI. The ratio of ST-segment resolution was calculated and considered complete if reaches ≥70% from the initial ST-segment elevation. We assessed the association of ST-segment resolution with in-hospital mortality. Results: Analysis of the electrocardiogram (ECG) showed that 21 patients (21%) had complete ST-segment (≥ 70%) resolution. No significant association was shown between ST-segment resolution and in-hospital mortality. Two out of 21 patients with complete ST-segment resolution died in the hospital and 6 out of 79 patients with incomplete ST-segment resolution died (P=0.77). There is no significant association between ST-segment resolution and coronary TIMI flow grades. In patients with complete ST-segment resolution, 19 patients had TIMI III flow and 2 patients had TIMI II flow. In patients with incomplete ST-segment resolution, 72 patients had TIMI III flow, 6 patients had TIMI II flow; and 1 patient had no-reflow (P=0.84). Conclusion: Complete ST-segment resolution in post-primary PCI settings has no significant association with in-hospital mortality. Absent or incomplete ST-segment resolution is not necessarily an indicator of coronary artery re-occlusion after primary PCI.