Effects of intracoronary low-dose prourokinase administration on ST-segment elevation in patients with myocardial infarction and a high thrombus burden: a randomized controlled trial

Microvascular reperfusion of fibrinolysis followed by percutaneous coronary intervention versus primary percutaneous coronary intervention for ST-segment-elevation acute myocardial infarction

Background

Primary percutaneous coronary intervention (PPCI) has been widely recognized as the preferred treatment for ST-segment-elevation myocardial infarction (STEMI). However, substantial numbers of STEMI patients cannot receive timely PPCI. Early fibrinolysis followed by routine percutaneous coronary intervention (FPCI) has been proposed as an effective and safe alternative for eligible patients. To date, few studies have compared FPCI with PPCI in terms of microvascular reperfusion. This study aimed to evaluate the microvascular function of FPCI and PPCI.

Methods

STEMI patients at the Peking University First Hospital and Miyun Hospital were enrolled in this retrospective study between January 2015 to December 2020. Microvascular function documented by the coronary angiography-derived index of microvascular resistance (caIMR) was measured at the final angiogram after revascularization. The primary end point was the caIMR of the culprit vessels. The secondary end points were in-hospital and follow-up major adverse cardiovascular events (MACE), including cardiovascular death, non-fatal recurrent myocardial infarction, target-vessel revascularization (TVR), and non-fatal stroke/transient ischemic attacks (TIA). Details of the adverse clinical events were obtained from telephone interviews and electronic medical record systems until January 2022.

Results

In total, 496 STEMI patients were enrolled in this cross-sectional retrospective study. Of these patients, 81 underwent FPCI, and 415 underwent PPCI. At the baseline, the PPCI patients had a higher-risk profile than the FPCI patients. The time from symptom onset to reperfusion therapy was significantly shorter in the FPCI group than the PPCI group (median 3.0 vs. 4.5 hours; P<0.001). The caIMR was significantly lower in the FPCI group than the PPCI group (median 20.34 vs. 40.33; P<0.001). The median follow-up duration was 4.1 years. During the follow-up period, the rate of MACE was lower in the FPCI group than the PPCI group [7 (10.1%) vs. 82 (20.8%), P=0.048]. After propensity score matching to adjust for the imbalances at the baseline, the caIMR remained significant and the clinical outcomes did not differ significantly between the two groups.

Conclusions

In eligible STEMI patients, clinically successful FPCI may be associated with better microvascular reperfusion and comparable clinical outcomes as compared with PPCI.