These are tough times for companies developing PFO closure devices. Various energy-based approaches have hit the rocks, and clinical trial enrollment difficulties have derailed others. Coherex Medical hopes for better results with technology that it describes as safe, user-friendly, and more effective than competing technologies. The company's FlatStent PFO closure system combines a self-expanding stent with tissue growth materials, and a design that provides multiple means to close the PFO and thus boost the chances for long-term success.

Medical device investors who have avoided heart failure, because of the long and uncertain development course of ventricular assist devices, should take another look. The minimally invasive revolution in heart failure, to some extent a logical extension of interventional cardiology's migration into other areas of structural heart disease like heart valves and PFOs, is providing new device opportunities, which have the potential to get to market sooner and at the same address an even larger patient population than heart failure devices that came before.

While the greater efficacy of drug-eluting stents (DES) compared to bare-metal stents is widely accepted, over the past year, data has continued to build showing that first-generation DES also have a higher late-stage in-stent thrombosis risk, a complication that can cause death 30% of the time, according to some estimates. The findings of these studies had some physicians at this year's World Congress of Cardiology calling for "an immediate halt to DES overuse." However, most conceded that additional randomized trials will be needed to fully understand the potential risks associated with these devices.