Long-term outcome of patients with ST-segment elevation myocardial infarction treated with low-dose intracoronary thrombolysis during primary percutaneous coronary intervention: the 5-year results of the DISSOLUTION Trial.

We tested the hypothesis that adjunctive thrombolysis at time of primary percutaneous coronary intervention (PCI) may affect favourably the long-term outcome of patients with ST elevation myocardial infarction (STEMI). To this end, we undertook a substudy of the DISSOLUTION (Delivery of thrombolytIcs before thrombectomy in patientS with ST-segment elevatiOn myocardiaL infarction Undergoing primary percuTaneous coronary interventION) trial. A total of 95 patients were randomized to local delivery of urokinase (n = 48) or placebo (n = 47). After PCI, a greater proportion of patients receiving urokinase had an improvement in myocardial perfusion, as indicated by a significantly higher final Thrombolysis in myocardial infarction (TIMI) grade 3, myocardial blush grade, and 60-min ST-segment resolution > 70%, as well as lower corrected TIMI frame count. At 1-year echocardiography, urokinase-treated patients exhibited significantly lower LV dimension, as well as higher LV ejection fraction and wall motion score index as compared with placebo-treated patients. At 5 years, major acute cardiovascular events (MACEs) were significantly less common in the urokinase group (P = 0.023), mainly due to a lower occurrence of hospitalisation for heart failure (P = 0.038). Multivariate analysis showed that factors independently associated with 5-year occurrence of MACEs were LV remodelling at 1-year echocardiography (P = 0.0001), 1-year LV ejection fraction (P = 0.0001), TIMI grade flow 0-2 (P = 0.0019), and age at time of PCI (P = 0.0173). In conclusion, low-dose intracoronary urokinase during primary PCI is associated with a more favourable 5-year outcome of patients with STEMI.