The role of primary angioplasty in patients presenting with acute myocardial infarction. American College of Emergency Physicians.
The role of primary coronary angioplasty in AMI patients presenting to the ED in cardiogenic shock or who have an absolute contraindication to fibrinolytic administration is well established. (1,2) In contrast, the role of primary angioplasty in patients with AMI eligible for fibrinolytic therapy is controversial.(3) A number of prospective trials have been conducted to address the issue of primary angioplasty versus fibrinolytic therapy with varying results. (4-12) Several of these studies have found modest but statistically significant benefits in short-term mortality, reinfarction rates, infarct size, and/or complication rates.(4-8) Other studies failed to confirm these benefits and found the 2 therapies to be of equal value.(9-12) Emergency physicians who practice in centers that offer primary angioplasty are frequently faced with the conundrum of whether to activate the emergency cardiac catheterization team or give fibrinolytic therapy in the ED. Likewise, emergency physicians who practice in a hospital that does not offer angioplasty face a similar dilemma if they have a patient with an AMI who they believe might benefit from immediate transfer to a facility with cardiac catheterization capabilities. A recent meta-analysis analyzed 10 prospective studies comparing primary angioplasty with intravenous fibrinolytic therapy and found that the mortality rate for 30 days or less was 4.4% for 1,290 patients treated with primary angioplasty compared with 6.5% for 1,316 patients treated with fibrinolytic agents (95% confidence intervals 0.46 to 0.49, P =.02).(13) When death was combined with nonfatal reinfarction, the rates were 7.2% for angioplasty and 11.9% for fibrinolytic therapy. In addition, angioplasty was associated with a statistically significant reduction in total strokes (0.7% versus 2.0%) and hemorrhagic stroke (0.1% versus 1.1%). Although the apparent benefit of primary angioplasty found in this analysis is enticing, 3 caveats must be considered before reaching a definitive conclusion. First, there is acknowledged potential for bias in both the quantitative review techniques and the enrollment practices of the individual studies reviewed.(14) Second, the time from presentation to the ED to inflation of the balloon in the angiography suite is relatively rapid in most of the studies used for the analysis, and in order for a center to duplicate these results, it is reasonable to presume they must be able to consistently equal or improve on the door-to-balloon times in the published studies. Although no clinical study definitively establishes the ideal door-to-balloon time, it may be reasonable to extrapolate that the balloon time ideally would be less than 90 minutes from time of ED diagnosis of AMI. Likewise, the experience of the interventionist is of critical importance and the procedure must be done at a high-volume center similar to those used in the reported trials. Third, there continue to be advances in interventional techniques, such as the use of platelet inhibitors and coronary stents, that may modify future results. Currently it can be concluded that primary angioplasty, when conducted in a timely manner in experienced hands, is a viable alternative to fibrinolytic therapy. When the element of time or experience is uncertain or cannot meet stringent criteria, fibrinolytic therapy remains the treatment of choice.
D000789:Angina, Unstable / Q000175:diagnosis / Q000628:therapy*; D015906:Angioplasty, Balloon, Coronary; D004636:Emergency Service, Hospital; D006801:Humans; D009203:Myocardial Infarction / Q000175:diagnosis / Q000628:therapy*; D011379:Prognosis; D015912:Thrombolytic Therapy