Impact of treatment delays on outcomes of primary percutaneous coronary intervention for acute myocardial infarction: Analysis from the CADILLAC trial

Background: The impact of treatment delays on outcomes after primary percutaneous coronary intervention for acute myocardial infarction is controversial. Methods: The CADILLAC trial randomized 2082 patients with acute myocardial infarction to stenting versus percutaneous transluminal coronary angioplasty, each with or without abciximab. Results: Earlier reperfusion (<3 vs 3-6 vs >6 hours) was associated with lower 1-year mortality (2.6% vs 4.3% vs 4.8%, P = .046 for <3 vs ≥3 hours), more frequent grade 2 to 3 myocardial blush (55% vs 53% vs 44%, P = .003), more frequent complete ST-segment resolution (64% vs 68% vs 47%, P = .006), and greater improvement in left ventricular function. Early reperfusion (<3 vs 3-6 vs ≥3 hours) was associated with lower mortality in high-risk patients (3.8% vs 6.9% vs 7.0%, P = .051 for <3 vs ≥3 hours) but not in low-risk patients (1.4% vs 0.6% vs 1.0%, P = .63). Door-to-balloon times were independently correlated with mortality in patients presenting early after the onset of symptoms (≤2 hours, hazard ratio 1.24, P = .013) but not late (>2 hours, heart rate 0.88, P = .33). Conclusions: Early reperfusion results in superior clinical outcomes, enhanced microvascular reperfusion, and better recovery of left ventricular function. Incremental treatment delays impact mortality more in high-risk versus low-risk patients and more in patients presenting early versus late after the onset of symptoms. These data emphasize the importance of minimizing treatment delays and have implications regarding patient triage for primary percutaneous coronary intervention.