Results of the DISCOVER trial, presented at ACC 2013, have shown that patients treated with the Direct Flow Medical Transcatheter Aortic Valve System (Direct Flow Medical) achieved excellent survivability and sustained haemodynamic improvements with minimal occurrence of aortic regurgitation at six months. Also presented was a larger cohort of 54 patients at 30 days that continued to demonstrate excellent outcomes.
The DISCOVER trial 30-day and six-month outcomes were presented by trial investigator Azeem Latib, San Raffaele Scientific Institute, Milan, Italy. Data showed that in 54 patients, there was 98% freedom from all-cause mortality at 30 days. The six-month results comprised from the pre-specified CE mark cohort demonstrated 92% freedom from all-cause mortality. The average age of patients was 84 years, with a Logistic EuroSCORE of 23.5%.
One hundred per cent of patients experienced mild or less aortic regurgitation at six months, with 74% of patients experiencing none/trace aortic regurgitation. The mean gradient (mmHg) pre-procedure to discharge as measured by transthoracic echo improved from 47.1 mmHg to 13.8 mmHg, and sustained these results at six months (13.7 mmHg). The haemodynamic outcomes were assessed and reported by an independent imaging core laboratory.
Secondary endpoints (VARC defined Safety) had a combined Safety Rate of 89 and 85%, respectively, at 30 days and six months. Within 30 days, there were two strokes and one patient experienced a myocardial infarction; however, there were no additional strokes or myocardial infarctions after 30 days. There was only one major vascular complication in the 54 patient cohort. The VARC Combined Device Success was 96.3%. No patient required rapid pacing or post-dilatation, minimising the risk of haemodynamic stress for patients.
“The Direct Flow Medical system is demonstrating very low mortality, sustained improvement in haemodynamics and minimal aortic regurgitation at six months,” said Latib. “It is also continuing to demonstrate excellent results in a larger patient cohort. The system enables us to optimise outcomes for our patients by allowing full haemodynamic assessment and the flexibility of repeated repositioning, as well as retrieval, improving the TAVI procedure and minimising risk.”
The Direct Flow Medical system received the CE mark in January 2013 and is currently available commercially in Europe. It has not been approved for use in the USA, Canada, or Japan.
The DISCOVER trial is a prospective, multicentre 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, which includes a distinctive heart valve with a metal-free frame that was delivered transfemorally via a flexible, 18 French delivery system.