NEW ORLEANS — Just 4% of U.S. acute MI patients transferred from one hospital to another for primary percutaneous intervention are treated within 90 minutes as recommended in recent guidelines, Brahmajee K. Nallamothu, M.D., reported at the annual scientific sessions of the American Heart Association.
This finding from the large National Registry of Myocardial Infarction (NRMI) database indicates an urgent need for improved process-of-care systems in order to minimize time delays for transferred MI patients, said Dr. Nallamothu of the University of Michigan, Ann Arbor.
PCI, when performed expeditiously, yields outcomes clearly superior to thrombolytic therapy. But at present, only about 20% of U.S. acute care hospitals have the capacity to perform primary PCI.
When a patient presents to a hospital without such capacity, the only options are on-site thrombolysis or immediate transfer to another facility for the procedure.
The pro-transfer argument is bolstered by several favorable European randomized controlled trials. However, these trials were conducted in countries with better-organized care and shorter transfer distances than are the norm in the United States. As a result, total door-to-balloon times in the randomized trials was only about 90 minutes. And the great majority of transferred American patients don't even come close to that speed of care.
Dr. Nallamothu's analysis of the NRMI-3 and −4 cohorts underscores that point. Of 4,278 consecutive acute MI patients transferred for primary PCI at 419 hospitals participating in the registry, only 4.2% had a door-to-balloon time of 90 minutes or less, as recommended in the recently issued AHA/American College of Cardiology guidelines (J. Am. Coll. Cardiol. 2004;44:671–719). The median door-to-balloon time was 180 minutes. Only 16.2% of transferred patients had a door-to-balloon time of 120 minutes or less, as recommended in earlier AHA/ACC guidelines. The great bulk of the time delay occurred because of prolonged transit times. More than 50% of transferred patients had transfer times in excess of 120 minutes.
NRMI is an ongoing project funded by Genentech. Dr. Nallamothu's study was supported by the National Heart, Lung, and Blood Institute.