Decreasing mortality with primary percutaneous coronary intervention in patients with acute myocardial infarction: The Mayo Clinic experience from 1991 through 1997

Objective: To characterize and determine the overall impact of changes in primary percutaneous coronary intervention (PCI) on the clinical outcome of patients presenting within 24 hours of acute myocardial infarction (AMI). Patients and Methods: We retrospectively analyzed a prospective PCI registry for 1073 consecutive patients undergoing primary PCI for AMI at the Mayo Clinic in Rochester, Minn, from 1991 through 1997. The primary outcome measure was mortality from any cause within 30 days and 1 year. Results: The number of patients treated for AMI by primary PCI per year increased from 119 in 1991 to 193 in 1997. Intracoronary stent use increased from 1.7% in 1991 to 64.8% in 1997 (P<.001). This coincided with an increase in ticlopidine use from 3.6% in 1994 to 62.1% in 1997 (P<.001) and in abciximab use from 2.7% in 1995 to 63.2% in 1997 (P<.001). An increase in β-blocker (58.3% to 75.3%; P<.001), angiotensin-converting enzyme inhibitor (0.9% to 40.0 %; P<.001), and 3-hydroxy-3-methylglutaryl coenzyme A reductase use (1.9% to 40.5%; P<.001) as well as a decrease in calcium channel antagonist (34.3% to 8.4%; P<.001) use occurred on discharge. From 1991 through 1997, there was a significant decrease in the 30-day mortality rate (10.1% to 5.2%; P=.05). The 1-year mortality rate also decreased (13.4% in 1991 to 10.4% in 1997) (P=.09). After adjustment for other confounding variables, treatment in more recent years was associated with a significant decrease in death at 30 days (odds ratio, 0.89; 95% confidence interval, 0.79-1.00; P=.05) and during long-term follow-up (odds ratio, 0.93; 95% confidence interval, 0.87-1.00; P=.04). Conclusions: Percutaneous coronary intervention methods of reperfusion for AMI, along with adjuvant pharmacotherapy, have changed over recent years and have been associated with improved short- and long-term survival.