Atmakuri SR et al. (2006) Initial experience with a magnetic navigation system for percutaneous coronary intervention in complex coronary artery lesions. J Am Coll Cardiol 47: 515–521

Difficulty in navigating guidewires through complex coronary artery lesions can lead to failure of percutaneous coronary intervention (PCI). A magnetic navigation system, recently approved by the FDA and now tested in a clinical trial, could help circumvent these problems. The Niobe® system (Stereotaxis, Inc., St Louis, MO) incorporates two permanent magnets that generate a 0.08 T magnetic field over the heart, a magnetic-tipped guidewire, and a software program to control the position of the magnets and deflect the guidewire. Navigation is viewed via a computer monitor.

A set of patients with tortuous or severely angulated coronary arteries underwent magnet-assisted PCI. For 46 patients this was the first attempt at intervention (primary group), whereas in 13 patients this was a re-intervention after conventional angioplasty had already failed (secondary group; mostly involving lesions within the circumflex artery territory). Crossing of the target lesion was largely successful, with 49 (89%) of 55 lesions crossed in the primary group and 9 (69%) of 13 in the secondary group. PCI was successful in 84% of primary cases and 62% of secondary cases. Although median times for crossing the lesion were longer in the secondary group than in the primary group—as were median procedure and fluoroscopy times—median time spent on guidewire placement in secondary procedures was less than in the initial, manual placement attempts.

Atmakuri et al. acknowledge that the equipment is in the early stages of development, but anticipate even greater success as the technology progresses.