Primary percutaneous coronary intervention for all?

REPERFUSION THERAPY WITH THROMBOLYSIS OR PRImary percutaneous coronary intervention (PCI) has been a major advance in the treatment of acute ST-segment elevation myocardial infarction (MI), with a 25% reduction in mortality with thrombolysis. Primary PCI has been considered in the American College of Cardiology/American Heart Association (ACC/AHA) guidelines in 1999 to be an alternative to thrombolysis. Since then, the number of trials and number of patients randomized has more than doubled to 21 trials and 6800 patients, all of which show clear benefit of PCI over thrombolysis. A metaanalysis of the randomized trials carried out through 1997 showed a clear reduction in mortality, recurrent MI, stroke, and intracranial hemorrhage. Mortality was reduced a relative 34% (6.5% for thrombolysis vs 4.4% for primary PCI), suggesting that 20 patients’ lives would be saved for every 1000 patients treated with primary PCI instead of thrombolytic therapy. Nonfatal reinfarction was reduced nearly 50% (5.3% for thrombolysis and 2.9% for PCI) and intracranial hemorrhage was essentially eliminated (1.1% with thrombolysis and 0.1% with PCI). In addition, cost appears to be similar between the 2 strategies, largely because many patients receive PCI following initial thrombolysis. Thus, based on these initial 10 randomized trials, primary PCI is considered a superior strategy both for efficacy and safety. The caveats to this conclusion were that these excellent results were obtained in the setting of clinical trials with experienced interventionists. Could these benefits be accomplished in the real world? Initial data from 2 registries actually suggested otherwise, with no difference in outcomes between patients treated with primary PCI vs thrombolysis. However, interventional cardiology has advanced dramatically during the last decade with the advent of stents and glycoprotein IIb/IIIa inhibitors, which have appeared to make a difference in outcomes in patients treated with an invasive strategy with unstable angina and non–ST elevation MI. More recent registry data show a benefit of primary PCI over thrombolysis. A study of more than 62000 thrombolyticeligible patients in the National Registry of Myocardial Infarction compared patients treated with primary PCI with those treated with thrombolysis. Because hospital volume is an important marker of overall skill, experience, and outcomes in performing primary PCI, patients were stratified into groups reflecting low-, intermediate-, and highvolume centers, based on primary PCI volume of the hospital at which they were treated. At high-volume centers, in-hospital mortality was lower among patients treated with primary PCI (3.4%) than with thrombolysis (5.4%)—ie, 20 lives saved for every 1000 patients treated with primary PCI. Mortality at intermediate-volume hospitals was also lower for patients who received PCI than for those who received thrombolysis (4.5% vs 5.9%). At low-volume hospitals, mortality was similar between thrombolytic-treated and primary PCI-treated patients. However, across all hospitals, primary PCI had a safety advantage, with nonfatal stroke occurring in 0.4% vs 1.1%. Thus, even at low-volume centers, which performed 16 or fewer primary PCI procedures per year, there was an overall advantage for primary PCI. Another major issue involves time delays that might attenuate any benefit of primary PCI. In an analysis of more than 27000 primary PCI-treated patients, increasing doorto-balloon time (time from hospital arrival to angioplasty balloon inflation) was found to be a significant factor related to increased mortality. Comparing patients who had an ideal door-to-balloon time of less than an hour, patients who had door-to-balloon times of more than 2 hours had a 40% to 60% increase in adjusted mortality. In accord with these data, the ACC/AHA guidelines recommend that patients undergoing primary PCI should have a door-toballoon time of 90 minutes ±30 minutes. Another key issue has been the need for surgical backup in the event of any complications of the primary PCI procedure. Registry data have suggested that immediate surgical capabilities may not be absolutely required because complication risks of primary PCI are quite low in the current era of coronary stenting. It is in this overall setting that the Atlantic Cardiovascular Patient Outcomes Research Team (C-PORT) study re-