Rapid Inflation-Deflation vs Pressure-Optimized Stenting During Primary PCI

BACKGROUND: Incomplete microvascular reperfusion during primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI) remains a major challenge. OBJECTIVES: This study sought to determine whether the pressure optimization protocol (POP) improves reperfusion outcomes compared with conventional rapid inflation-deflation stenting in patients undergoing primary PCI for STEMI. METHODS: In this multicenter randomized trial with blinded endpoint assessment, patients undergoing primary PCI were assigned 1:1 to POP (stent inflation to ≥14 atm maintained until pressure stability, defined as no pressure drop ≥0.3 atm over 30 seconds) or conventional rapid inflation-deflation stenting. The primary endpoint was hierarchical reperfusion success, analyzed using the Finkelstein-Schoenfeld unmatched WIN ratio: ST-segment resolution ≥70% at 90 minutes, final TIMI grade 3, and absence of slow-flow/no-reflow. RESULTS: Between September 30, 2024, and November 11, 2025, 607 patients underwent randomization (POP arm, n = 307; conventional arm, n = 300). POP improved the primary hierarchical reperfusion endpoint (WIN ratio: 1.42; 95% CI: 1.11-1.79; P = 0.004). The net WIN difference was +12.64% (95% CI: 3.69-20.98), driven mainly by the first 2 hierarchical components, ST-segment resolution ≥70% (+5.70%; 95% CI: -1.89 to 12.56) and final TIMI grade 3 flow (+5.95%; 95% CI: 1.80-10.00). Postdilation was less frequent with POP (213 of 326 stents [65.3%] vs 294 of 323 [91.0%]; P < 0.001). At median follow-up of 30 days (IQR: 29-32), major adverse cardiovascular events (death, myocardial infarction, stent thrombosis, or stroke) occurred in 6 of 307 vs 12 of 300 patients; Kaplan-Meier estimated event rates were 2.0% (95% CI: 0.4-3.5) and 4.1% (95% CI: 1.8-6.3), respectively (HR: 0.49; 95% CI: 0.18-1.31; P = 0.15). CONCLUSIONS: Among patients with STEMI undergoing primary PCI, pressure-optimized stent inflation resulted in significantly higher rates of successful reperfusion than conventional stenting and reduced need for post dilation. A trend toward fewer 30-day major adverse cardiovascular events was observed. Larger trials are warranted to assess effects on longer-term clinical outcomes. (RAPID-POP: A Randomized Controlled Trial; NCT06430892).