Reperfusion before percutaneous coronary intervention in ST-elevation myocardial infarction patients is associated with lower N-terminal pro-brain natriuretic peptide levels during follow-up, irrespective of pre-treatment with full-dose fibrinolysis

AIMS: N-terminal pro-brain natriuretic peptide (NT-proBNP) levels predict outcomes in ST-elevation myocardial infarction patients treated with fibrinolysis or primary percutaneous coronary intervention (PCI). However, its role in facilitated PCI has not yet been assessed; it may be a tool to evaluate the lower event rates with primary PCI in ASSENT-4. METHODS AND RESULTS: In ASSENT-4, 1667 patients were randomized to tenecteplase (TNK) followed by PCI or primary PCI alone. Baseline, discharge/Day 7, and 90-day NT-proBNP levels were available for 1008, 971, and 813 patients. Increasing quartiles of baseline NT-proBNP levels were associated with a higher risk of the combined endpoint of death, heart failure, and shock at 90 days and 1-year mortality (P < 0.001). Events were more common with TNK + PCI, regardless of baseline NT-proBNP quartile. When analysing baseline NT-proBNP as a continuous variable, no treatment interaction was observed for the primary endpoint (P = 0.17) or 1-year mortality (P = 0.08). Overall, NT-proBNP levels at Day 7 or 90 were not different between the two treatments. In patients with TIMI 2-3 flow before PCI, NT-proBNP at Day 90 was lower in PCI-only patients (P = 0.01), although no interaction was observed (P = 0.14). In TNK-pre-treated patients without reperfusion (TIMI 0-1) after PCI, NT-proBNP levels at Day 7 or 90 were not significantly higher than in PCI patients. CONCLUSION: Baseline NT-proBNP predicts outcome at 90 days and 1 year in patients undergoing PCI with or without facilitation with TNK. A higher rate of reperfusion in lytic-pre-treated patients did not result in lower NT-proBNP during follow-up. Thus, baseline and subsequent NT-proBNP levels do not explain the lower mortality rate with PCI alone seen in this trial.