Short-term outcomes after percutaneous coronary intervention: effects of stenting and institutional volume shifts.

BACKGROUND: This study examines how the dissemination of stenting and procedural shifts to high-volume facilities have affected short-term outcomes after percutaneous coronary intervention (PCI). METHODS: Discharge information from the 1994 and 1997 US Nationwide Inpatient Sample was used. Data from 1994 involved 84,036 angioplasties, 27.3% of which were performed for acute myocardial infarction (AMI), at a time when stents were generally unavailable. Data from 1997 included 118,548 angioplasties, 30.2% of which were performed for AMI and 59% of which involved stenting. Outcomes included same-admission mortality and same-admission bypass grafting surgery (CABG). RESULTS: Compared with 1994, in 1997 stents were in widespread use, and there was a significant shift in PCI procedures to high-volume facilities. There was no significant difference in overall mortality rates between 1994 and 1997. However, same-admission CABG rates were lower in 1997 than in 1994 for the AMI group (2.9% vs 4.7%, P <.0001) and for the no-AMI group (1.8% vs 3.0%, P <.0001), which was attributable almost entirely to stenting. For 1997 only, patients receiving stents had a lower mortality rate than patients undergoing PCI without stenting (AMI 2.7% vs 4.7%, P <.0001, no AMI 0.7% vs 0.9%, P =.004). CONCLUSIONS: Despite the dissemination of stenting and shifts to high-volume facilities, overall mortality rates after PCI have not significantly changed. However, patients undergoing stenting in 1997 had a significantly lower mortality rate than patients who did not undergo stenting, suggesting that stents may prevent inhospital deaths. Furthermore, same-admission CABG rates have decreased dramatically, an association seen with the introduction of stenting, but not with volume shifts.