Coronary Reperfusion: Stent vs. Fibrinolysis
Abstract & Commentary
Source: Le May MR, et al. Stenting versus thrombolysis in acute myocardial infarction trial (STAT). J Am Coll Cardiol 2001;37:985-991.
Early and complete reperfusion is the primary goal for the treatment of acute myocardial infarction (AMI) in the emergent setting. However, the best reperfusion strategy remains controversial. Pharmacologic therapy (fibrinolysis/thrombolysis) and mechanical reperfusion (angioplasty or percutaneous transluminal coronary angioplasty [PTCA]) each have advantages and disadvantages that depend on the patient’s clinical presentation and available hospital resources. Recent work with the use of stents has shown significant benefit over standard PTCA in the setting of AMI. This study, termed STAT, directly compares the use of mechanical stents to pharmacologic fibrinolysis.
Experienced investigators at an university medical center randomized 123 AMI patients to stenting (62) or accelerated-dosed tissue plasminogen activator (tPA, 61). Exclusion criteria were cardiogenic shock, active bleeding, history of stroke, prior stent or coronary artery bypass graft, recent surgery, trauma, or PTCA. The primary end point was a composite of death, reinfarction, stroke, or repeat target vessel revascularization (TVR) for ischemia. Stent placement was successful in 50 (81%) subjects, and the number of patients with TIMI-3 (normal) angiographic flow increased from one to 46 in the stent group. All patients assigned to tPA received the medication, seven of which (11.5%) underwent rescue PTCA due to lytic failure.
The combined end point of death, reinfarction, stroke, and repeat TVR was significantly lower for the stent vs. tPA group during hospitalization (19% vs 47%), at six weeks (19% vs 51%), and at six months (24% vs 56%). Most of this difference was due to repeat TVR rates, as the incidence of death, stroke, and reinfarction was not significantly different between the two groups when studied separately. Recurrent unstable ischemia after treatment was significantly lower in the stent group at six months (9.7 vs 26.2%). Median lengths of hospital stay were shorter for those who were in the stent group (4 vs 7 days). Based on their results, the authors conclude that primary stenting in the AMI setting may be an attractive alternative to fibrinolytic therapy in terms of outcome and length of hospitalization.
Comment by Theodore C. Chan, MD, FACEP
New advances continue to alter the ongoing debate between pharmacologic and mechanical reperfusion strategies for AMI. Newer fibrinolytic agents, such as tenecteplase, have improved the ease of administration and reduced the adverse effects associated with pharmacologic therapy. Stenting has been shown to have additional benefits over standard angioplasty for mechanical reperfusion.1
In this study comparing stenting to fibrinolysis, stenting demonstrated a clear advantage over pharmacologic reperfusion in terms of recurrent unstable ischemia and the need for repeat TVR within six months. In addition, stented patients had significantly shorter hospital stays. However, these results should be viewed with some caution. First, this study was limited by its small sample size, which may explain why no significant differences were found when comparing rates of death, reinfarction, and stroke separately (as opposed to the combined end point which included repeat TVR). Second, prior studies have shown that emergent mechanical reperfusion, unlike fibrinolytic therapy, varies with hospital resources, experience, and volume.2 This study was conducted at a single institution with experience in mechanical reperfusion and a high volume of angioplasties (> 1200 per year). The benefit of stenting (as well as the shorter hospital stays) seen in this study may be limited only to high-volume, experienced centers.
It is interesting to note that routine use of platelet glycoprotein inhibitors initially was discouraged. When growing evidence suggested benefit from stenting, the use of these agents was left to the discretion of the physician and, ultimately, 12 patients in the stent group received abciximab. Although no analysis was performed, recent reports suggest significant benefit from the combined therapy of stenting and platelet inhibition over fibrinolysis.3 There likely will be greater interest in and research on combination therapies (platelet inhibition, fibrinolysis, and mechanical reperfusion) as optimal strategies for AMI treatment in the future.4
References
1. Grines CL, et al. Coronary angioplasty with or with-out stent implantation for acute myocardial infarction. N Engl J Med 1999;341:1949-1956.
2. Magid DJ, et al. Relation between hospital primary angioplasty volume and mortality for patients with acute MI treated with primary angioplasty vs thrombolytic therapy. JAMA 2000;284:313-318.
3. Schomig A, et al. Coronary stenting plus platelet glycoprotein IIb/IIIa blockade compared with tissue plasminogen activator in acute myocardial infarction. N Engl J Med 2000;343:385-391.
4. Sayre MR. Facilitated percutaneous coronary intervention for acute myocardial infarction. J Emerg Med 2000;19(3 suppl):27S-32S.
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