A randomized comparison of the magnetic navigation system versus conventional percutaneous coronary intervention

Objective : A randomized comparison of the magnetic navigation system (MNS) to conventional guidewire techniques in percutaneous coronary interventions. Background : The MNS precisely directs a magnetized guidewire in vivo through two permanent external magnets. Methods : A total of 111 consecutive patients were enrolled. Crossing success, crossing‐/fluoroscopy times, and contrast usage were directly compared. Lesions were classified according to the AHA/ACC criteria. Three tertiles of vessel/lesion complexity [low (<5), medium (6–10) and high (>10)] were defined using 3D reconstructions and angiographic information. Results : The crossing success for magnetic and the conventional wires were 93.3and 95.6%, respectively. Crossing and fluoroscopy times were longer with the magnetic wires (72.9 ± 50.3 sec vs. 58.1 ± 47.2 sec, P < 0.001 and 66.2 ± 44.1 sec vs. 55.2 ± 44.4 sec, P = 0.03, respectively). In vessels with low and medium complexity the magnetic wires had significantly longer times ( P < 0.001) but for those with high scores (>10) a trend towards shorter times was observed. The MNS resulted in a small but significant reduction in contrast usage (2.3 ± 3.5 ml vs. 4.5 ± 4.4 ml, P < 0.001). Moreover by superimposing a virtual roadmap of the vessel on the live fluoroscopy image 48% of the lesions were crossed without requiring contrast agents with the MNS. Conclusion : The MNS has comparable crossing success to conventional PCI. It is relatively slower but there is a trend to support a potential advantage in more complex vessels. By simultaneously employing a virtual roadmap there is a small but significant reduction in contrast usage. © 2008 Wiley‐Liss, Inc.