Thrombolysis versus primary percutaneous coronary intervention in patients with suspected ST-elevation myocardial infarction - a SWEDEHEART observational study
Authors: Isma B , Von Koch S , Andell P , Reitan C , Jernberg T , Olivecrona G K , Koul S , Sarno G , Andersson J , Erlinge D , Mohammad M A 
Published: October 2024

Abstract

Background
Primary percutaneous coronary intervention (PCI) is the recommended reperfusion strategy in ST-elevation myocardial infarction (STEMI) patients provided time to reperfusion is ≤120 minutes. In patients presenting early with an estimated time to reperfusion &gt;120 minutes, thrombolytic therapy should be considered according to European Society of Cardiology guidelines. However, there is a lack of contemporary data on patients treated with thrombolysis.

Aims
Our aim was to determine how often thrombolysis was administered in STEMI patients having an estimated time to reperfusion of &gt;120 minutes and to study outcome differences between patients treated with thrombolysis compared to those treated with primary PCI.

Methods
We calculated transport times to nearest primary PCI centre using three-digit zip codes for each patient enrolled in the SWEDEHEART registry from 2008–2021 in the five geographic areas in Sweden routinely using thrombolysis and included those with &gt;120 min estimated transportation time to reperfusion time. Patients without ST-elevations on prehospital ECG and ongoing chest pain as well as patients with left bundle branch block, pacemaker rhythm and patients with contraindications to thrombolysis were excluded. Patients were grouped by received reperfusion therapy with prehospital thrombolysis or no prehospital thrombolysis and studied with regard to 1- and 3-year mortality using Kaplan-Meier failure estimates and Cox regression adjusted for difference in baseline characteristics.

Results
A total of 1,840 patients were included of whom 1,381 (75.1%) received thrombolysis. A final diagnosis of STEMI was observed in 92.6% of patients receiving thrombolysis and 80.2% of patients treated with primary PCI. The median transport time estimate to a PCI centre was 153 minutes in both groups. Median time from onset of symptoms to reperfusion therapy was 131 minutes for the thrombolysis group and 255 minutes for the PCI group. Patients who received thrombolysis were on average 2 years younger and had fewer comorbidities such as diabetes, cancer and heart failure. Among patients treated with thrombolysis, a total of 42.7% of patients underwent rescue PCI. There was no significant difference in 365-day mortality (6.7% vs 11.8%, adjusted HR 0.84, 95% CI: 0.59-1.19, p=0.33) or 3-year mortality rates (10.3% vs 16.6%, adjusted HR 0.89, 95% CI: 0.66-1.19, p=0.44) between patients treated with thrombolysis and primary PCI groups.

Conclusions
In this population-based study of patients where primary PCI cannot be expeditiously used, we observed a commendable adherence rate of 75% to the ESC guidelines for thrombolysis treatment. Moreover, our findings revealed that the administration of thrombolysis was not associated with any discernible benefits or harm.Unadjusted and adjusted Cox-modelKaplan-Meier survival analysis