Times to treatment in transfer patients undergoing primary percutaneous coronary intervention in the United States - National Registry of Myocardial Infarction (NRMI)-3/4 analysis

Background - Treatment delays in patients with ST-segment - elevation myocardial infarction ( STEMI) transferred for primary percutaneous coronary intervention (PCI) may decrease the advantage of this strategy over on-site fibrinolytic therapy that has been demonstrated in recent clinical trials. Accordingly, we sought to describe patterns of times to treatment in patients undergoing interhospital transfer for primary PCI in the United States. Methods and Results - We analyzed patients with STEMI undergoing interhospital transfer for primary PCI between January 1999 and December 2002 in the National Registry of Myocardial Infarction. The primary outcome was "total" door-to-balloon time measured from time of arrival at the initial hospital to time of balloon inflation at the PCI hospital. Multivariable hierarchical models were used to assess the relationship of total door-to-balloon time with patient and hospital characteristics. Among 4278 patients transferred for primary PCI at 419 hospitals, the median total door-to-balloon time was 180 minutes, with only 4.2% of patients treated within 90 minutes, the benchmark recommended by national quality guidelines. Comorbid conditions, absence of chest pain, delayed presentation after symptom onset, less specific ECG findings, and hospital presentation during off-hours were associated with longer total door-to-balloon times. Patients at teaching hospitals in rural areas also had significantly longer times to treatment. Conclusions - Total door-to-balloon times for transfer patients undergoing primary PCI in the United States rarely achieve guideline-recommended benchmarks, and current decision making should take these times into account. For the full benefits of primary PCI to be realized in transfer patients, improved systems are urgently needed to minimize total door-to-balloon times.