Changing features of stent-supported primary angioplasty for acute myocardial infarction: Impact of new flexible stents

Although primary coronary stenting for acute myocardial infarction (AMI) ha s been reported to be superior to primary percutaneous transluminal coronar y angioplasty (PTCA), cautious entry criteria resulted in low-risk populati ons in these studies. This study was undertaken to delineate factors that h ave not been clarified by randomized multicenter studies and is based on th e results of stent-supported primary PTCA for AMI using second-generation n ew stents. In 1994-1998, 355 AMI patients were studied < 12 hours after ons et. The patients were divided into two groups: group 1 (n = 175) was treate d in 1994-1996 and group 2 (n = 180) in 1997-1998. In group 1, bailout sten ting was performed in 17% of the patients for acute coronary dissection or occlusion with use of Palmaz-Schatz stents. In group 2, stenting was perfor med in 62% of the patients for suboptimal coronary dilatation and dissectio n or occlusion, using second-generation flexible stents with excellent radi al force in 65% of them (Multilink, GFX, and NIR). In-hospital death and re infarction occurred in 7.4% of group 1 and 5.0% of group 2 patients, and fo llow-up death and reinfarction in 4.0% of group 1 and 0.6% of group 2 patie nts (p < 0.05). In-hospital target vessel revascularization was performed i n 8.6% of group 1 and 3.3% of group 2 patients (p < 0.05), and follow-up ta rget vessel revascularization in 21.1% of group 1 and 11.7% of group 2 pati ents (p < 0.02). Thus, the total adverse clinical event rates were 36.0% in group 1 and 18.3% in group 2 (p < 0.01). In conclusion, outcomes of stent- supported coronary intervention in nonselected AMI patients have improved a long with the availability of second-generation flexible stents, approachin g the outcomes of primary stent studies in highly selected patients.