Introduction: Novel Approaches to Managing Bradycardia during Coronary Rheolytic Thrombectomy

Primary percutaneous coronary intervention (PCI) is the preferred treatment for revascularizing infarct-related arteries in patients experiencing acute myocardial infarction (AMI). Thrombolytic occlusion of the coronary artery is the inciting event responsible for AMI, and angiographic evidence of a large thrombus has been associated with poor clinical outcomes. Several studies1–4 have reported the benefits of rheolytic thrombectomy (RT) as an adjunct to PCI for AMI patients. The VeGAS studies,1,2 randomized studies sponsored by Possis Medical, Inc., under an Investigational Device Exemption (IDE) approved by the US Food and Drug Administration, demonstrated that the AngioJet® Rheolytic™ Thrombectomy System was a safe and effective treatment for intracoronary thrombus. These studies also reported a lower in-hospital complication rate, a shorter mean length of stay and a lower total mean cost of initial treatment in the AngioJet arm when compared to the drug treatment arm. Antoniucci et al3 conducted a one-site, prospective, randomized study comparing AngioJet and stenting with stenting alone in patients with ST-segment elevation myocardial infarction (STEMI). In this study, STEMI patients treated with AngioJet and stenting exhibited a higher rate of ST resolution, a higher rate of thrombolysis in myocardial infarction grade 3 flow in the infarcted arteries and a smaller average final infarct size when compared with the patients treated with stenting alone. Sianos et al4 conducted an extensive review of 900 STEMI patients treated with drug-eluting stents at the ThoraxCenter in Rotterdam. They noted that patients with large thrombus unresolved prior to stenting had higher rates of subsequent stent thrombosis, death and repeat MI than did patients presenting with little or no thrombus prior to stenting. They also observed that patients presenting with large thrombus in whom AngioJet was used for removal prior to stenting had low rates of subsequent stent thrombosis, death and repeat MI, similar to those patients presenting with little or no thrombus prior to stenting. While the benefits of RT use have been demonstrated, transient and symptomatic bradyarrhythmias have been observed in a subset of patients. The mechanisms of these dysrhythmias remain unclear, although a persuasive argument that the Bezold-Jarish reflex may be involved is presented in this supplement. Up to now, management of such bradyarrhythmias has been accomplished, albeit imperfectly, through temporary transvenous pacing. Labeling for coronary catheters has indicated “…placing a temporary pacing catheter to support the patient…”5 Yet temporary pacing is not without risks in this population. This supplement presents a series of novel approaches to manage bradyarrhythmias during RT in coronary applications. Since many of our contributors have been working on these “new” techniques for several years, we are pleased to present data along with their insights and experiences. It is our wish that this information from a variety of colleagues working on the leading edge of interventional cardiology informs and inspires the practice of all who manage patients with MI.

1. Kuntz RE, Baim DS, Cohen DJ, et al. A trial comparing rheolytic thrombectomy with intracoronary urokinase for coronary and vein graft thrombus (the Vein Graft AngioJet Study [VeGAS 2]). Am J Cardiol 2002;89:326–330.
2. Cohen DJ, Ramee S, Baim DS, et al; Vein Graft AngioJet Study (VeGAS) 2 Investigators. Economic assessment of rheolytic thrombectomy versus intracoronary urokinase for treatment of extensive intracoronary thrombus: Results from a randomized clinical trial. Am Heart J 2001;142:648–656.
3. Antoniucci D, Valenti R, Migliorini A, et al. Comparison of rheolytic thrombectomy before direct infarct artery stenting versus direct stenting alone in patients undergoing percutaneous coronary intervention for acute myocardial infarction. Am J Cardiol 2004;93:1033–1035.
4. Sianos G, Papafaklis MI, Daemen J, et al. Angiographic stent thrombosis after routine use of drug-eluting stents in ST-segment elevation myocardial infarction: The importance of thrombus burden. J Am Coll Cardiol 2007;50:573–583.
5. Spiroflex Coronary Catheter, 105979, Rev. 3 [instructions for use]. Minneapolis, MN: Possis Medical, Inc.