The market for atrial fibrillation catheter ablation devices continues to grow even as the field wrestles with basic questions and as new study results may dampen enthusiasm for some technologies. Though strategics dominate this sector, innovators with new approaches to ablation and mapping hope to help resolve unknowns and take a piece of this vast and underpenetrated market.

As part of START-UP’s annual Series A coverage, this year’s spotlight shines on the Novartis Venture Funds, the most active corporate group in biopharma company formation, and Versant Ventures, an unlikely device champion.

Device therapies for atrial fibrillation (AF) have so far failed to result in compelling efficacy across all types of disease and patients. The rates of elimination of AF following a catheter ablation procedure range from 30% to 80% according to the type of patient and the definition of success. The question of why success rates aren’t yet sufficient after a great deal of investment is an area of active pursuit, and one that opens up the door for next-generation AF device companies seeking to improve upon the results achieved to date.

Three years ago, the FDA approved Johnson & Johnson’s ThermoCool, the first in a series of ablation catheters specifically designed to halt atrial fibrillation. Despite these advances, the long-term success rates of catheter ablation procedures remain low, opening the door for start-ups to devise new approaches.