DANAMI-2 Trial: More Comparison of Fibrinolysis vs. Primary PTCA
Abstract & Commentary
Source: Anderson HR, et al. A comparison of coronary angioplasty with fibrinolytic therapy in acute myocardial infarction. The "DANAMI-2" Trial. N Engl J Med 2003;349: 733-742.
Well-done studies have established that percutaneous transluminal coronary angioplasty (PTCA) is superior to fibrinolytic administration for the reduction of early death (7% vs 9%), non fatal re-infarction (3% vs 7%), or stroke (1% vs 2%), provided that the center where it is performed has expertise with the procedure, and door-to-balloon time can be kept to 90 minutes or less.1 Overall, when performed by experienced operators at high-volume centers, PTCA is expected to save 20 lives and result in 60 fewer subsequent events for every 1000 patients treated when compared to fibrinolysis. Despite this fact, the majority of patients with acute myocardial infarction (AMI) in the United States receive fibrinolytic therapy, as most hospitals do not have around-the-clock angioplasty capabilities. Fibrinolysis becomes the default treatment regimen at these centers, as there is assumed to be significant risk involved in patient transfer for primary PTCA, given the inherent delays this can represent as well as the assumed risk of transportation during active myocardial infarction.
The DANAMI-2 study is an attempt to definitively answer this question. Anderson and his Danish colleagues randomly assigned 1572 patients presenting with AMI at one of 24 referral hospitals to treatment with either primary PTCA at one of five regional centers or accelerated intravenous alteplase at the referral hospital. They report that these 24 referral hospitals and five regional centers serve approximately 62% of the Danish population. The primary end-point for the study was a composite of death, reinfarction, or disabling stroke at 30 days.
The reported results from the study are impressive. The primary endpoint was reached in 8.5% of the patients transferred for PTCA, vs. 14.2% in the fibrinolysis group (p = 0.0002). Virtually all of the difference in the two groups was driven by the reduction in the rate of reinfarction (6.7% for PTCA, 12.3% for fibrinolytic).
There was no significant difference in the overall rate of death or stroke between the two groups. Notably, 96% of patients were transferred within two hours of randomization. Median interval from randomization to start of transport was 50 minutes, and median transport time was 32 minutes. Overall, the median interval from symptom onset to treatment for the fibrinolysis group was 169 minutes (interquartile range 110-270), and 224 minutes for the PTCA group (interquartile range 171-317). Also important to note was the fact that there were no deaths en route. Described events during transport include 14 patients who developed atrial fibrillation, 13 patients who developed advanced atrioventricular block, and eight patients who developed ventricular fibrillation. One patient developed refractory ventricular fibrillation en route, and died one hour after arrival at the regional center.
Commentary by Andrew D. Perron, MD, FACEP
This is an important study that has the potential to impact the everyday practice of our specialty. The authors, as well as an accompanying editorial,2 advocate a clear change in the "door-to-balloon in 90 minutes or less or else fibrinolysis" algorithm that has become ingrained in our practice. This well-done, randomized study extends this window of opportunity to improve patient outcome beyond 90 minutes, provided that transfer can be accomplished in fewer than two hours. An absolute reduction of 5.7% in a combined end-point of re-infarction, death, and stroke can be achieved, according to these authors, with the adoption of this strategy.
So what are the barriers to implementing this strategy in the United States right now? As always, the devil is in the details. As the authors of the study point out, the study was "designed to minimize all components of delay in treatment." All patients were brought primarily to the coronary care unit (bypassing the ED), where a decision was made and randomization occurred while the transporting ambulance crew waited with the patient. The receiving hospital’s angioplasty suite was contacted directly, and the patient was brought directly to that area on arrival. Ideal, yes, but not necessarily real-world. Delay will be compounded in overcrowded EDs, where door-to-triage time, triage-to-bed, bed-to ECG, and ECG-to-physician time all can slow this process. Similarly, over-taxed emergency medical services may have to choose between sending ambulances out of their coverage areas or calling in on-call teams for such transports.
The accompanying editorial to this article asks: "Primary Angioplasty for Acute Myocardial Infarction—Is It Worth the Wait?" This important study concludes that the answer is a strong "yes." What remains to be seen is whether these results can be reproduced in our medical system, which has not been "designed to minimize all components of delay in treatment."
Dr. Perron is Associate Residency Director, Department of Emergency Medicine, Maine Medical Center, Portland, ME.
References
1. Keeley EC, et al. Primary angioplasty versus intravenous thrombolytic therapy for acute myocardial infarction: A review of 23 randomised trials. Lancet 2003;361:13-20.
2. Jacobs AK Primary angioplasty for acute myocardial infarction—is it worth the wait? N Engl J Med 2003; 349:8:798-800.
Well-done studies have established that percutaneous transluminal coronary angioplasty (PTCA) is superior to fibrinolytic administration for the reduction of early death (7% vs 9%), non fatal re-infarction (3% vs 7%), or stroke (1% vs 2%), provided that the center where it is performed has expertise with the procedure, and door-to-balloon time can be kept to 90 minutes or less.You have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
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