Initial experience with a magnetic navigation system for percutaneous coronary intervention in complex coronary artery lesions

OBJECTIVES: The aim of this study was to evaluate the feasibility of a magnetic-assisted navigation system during percutaneous coronary intervention (PCI) of tortuous and severely angulated coronary arteries. BACKGROUND: The magnetic navigation system consists of two 0.8-T permanent magnets which generate a magnetic field over the heart. Altering the magnetic vector deflects a coronary guidewire with a magnetic tip. METHODS: Patients were selected for magnetic-assisted intervention (MAI) for potentially difficult to cross lesions. The time required for placement of the guidewire, total procedure time, fluoroscopy time, and amount of contrast for the procedure were recorded. There were a total of 59 patients undergoing PCI of 68 lesions. RESULTS: Patients were grouped based on whether MAI was attempted as a first option ("primary attempt"; n = 46) or following failure to pass a conventional guidewire ("secondary attempt"; n = 13). The target lesion was successfully crossed in 49 of 55 lesions (89%) and 9 of 13 lesions (69%) in patients undergoing primary and secondary attempts, respectively. The procedural success rates were 84% and 62%, respectively. Most lesions were located in the circumflex artery territory (39% and 62% of lesions, respectively). The median (25th and 75th percentiles) time for crossing the lesion was longer in the secondary attempt group (14.8 [5, 15.5] vs. 28.9 [8, 38] min). Median fluoroscopy time and median contrast used were also higher among the secondary attempt group. CONCLUSIONS: This first report of MAI suggests that it may become a useful adjunct for wire placement in difficult coronary interventions.