SANTA ROSA -- Direct Flow Medical Inc., a Santa Rosa-based developer of transcatheter heart valves, recently won approval on two new patents, one from the U.S. Patent and Trademark Office and the second from the Japan Patent Office.

The patents come as Direct Flow, founded in 2004, seeks to bolster its presence in the aortic valve market by improving on clinical issues associated with the existing commercial valves available.

Its new patents are for proprietary technology for an artificial aortic valve with a metal-free frame and a flexible, low-profile delivery system that can eliminate aortic regurgitation, which can occur when the valve doesn't close tightly enough. That can lead to the flow of blood from the aorta into the left ventricle of the heart, which can eventually be a predictor of long-term mortality.

The company also announced results of a clinical discover trial, presented at the annual meeting of the American College of Cardiology, which found "excellent survivability" and improvements in blood movement with minimal occurrence of aortic regurgitation at six months for patients treated with its transcatheter aortic valve system.

The company now has 13 issued U.S. patents and 24 additional patent applications filed in the U.S. or under the Patent Cooperation Treaty.

“With issued U.S. and foreign patents, our intellectual property portfolio has global breadth, and we intend to continue to expand it as we develop and refine additional technologies,” said Gordon Bishop, Direct Flow’s chief technology officer, co-founder and inventor of the two recently awarded patents.

The discovery trial was a prospective study of up to 100 patients conducted at up to 10 European sites of patients with severe aortic valve stenosis who require replacement of their native aortic valve but are at extreme risk for open surgical repair. The device studied was the Direct Flow Medical Transcatheter Aortic Valve System.

“The Direct Flow Medical system is demonstrating very low mortality, sustained improvement in hemodynamics and minimal aortic regurgitation at six months,” said Dr. Latib. “It is also continuing to demonstrate excellent results in a larger patient cohort. The system enables us to optimize outcomes for our patients by allowing full hemodynamic assessment and the flexibility of repeated repositioning, as well as retrieval, improving the TAVR procedure and minimizing risk.”

Direct Flow Medical system received the CE Mark in January 2013 and is currently available commercially in Europe.

The recent trial results showed that 100 percent of  patients experienced mild or less aortic regurgitation at six months, with 74 percent of patients experiencing either none or trace amounts of aortic regurgitation. The trial monitored 30-day and six-month outcomes, which were presented by trial investigator Azeem Latib, MD, from San Raffaele Scientific Institute in Milan, Italy.