RESPECT PFO/Stroke Trial Completes Enrollment

Shelley Wood

January 04, 2012

January 4, 2012 (St Paul, MN) — After eight years running, investigators for the RESPECT trial, looking at patent foramen ovale (PFO) closure for recurrent stroke, say they have collected enough events to stop the trial [1].

The trial sponsor, St Jude Medical, announced the decision yesterday. The company said only that the trial had "met a stopping rule . . . triggered by reaching the protocol-required number of primary events in the trial, defined as stroke and all-cause mortality."

RESPECT is one of a dwindling number of studies still investigating the strategy of PFO closure for cryptogenic stroke. Smaller, nonrandomized studies have for years suggested that closing a PFO can reduce or prevent recurrent stroke, and several devices are approved outside the US for this indication.

But the few randomized trials in this field have, for years, struggled to enroll sufficient numbers of patients, in large part due to off-label use of closure devices by physicians already convinced that PFO closure can cure stroke. As reported by heartwire, the first trial to make it across the finish line was CLOSURE, which found that PFO closure using NMT Medical's Starflex device was not superior to best medical therapy for preventing recurrent stroke or transient ischemic attack (TIA). This disappointing result only exacerbated enrollment problems for other trials and spawned intense speculation on ideal device and trial design. CLOSURE was stopped after a prespecified number of patients had reached two-year follow-up.

According to St Jude, RESPECT has enrolled 980 patients over its eight years running, yielding more than 2300 patient-years of data. The company expects to present the results "at a major medical meeting sometime in 2012."

Commenting on the RESPECT news for heartwire, lead investigator for CLOSURE, Dr Anthony Furlan (Case Western Reserve University, Cleveland, OH), observed that the number of patients in RESPECT is "essentially" the same as CLOSURE, with 909 patients, "so it will be interesting to compare end points, especially two-year stroke rates, [which were] about 3% in CLOSURE in both the device and medical arm."

Dr Jonathan Tobis (University of California, Los Angeles), an investigator in RESPECT, called the announcement "exciting news" but said he had no more information beyond what was in the press release.

The company has not said publicly which "stopping rule" in RESPECT triggered the decision to stop enrollment.

St Jude acquired the Amplatzer technology when it bought AGA Medical in 2010; a second St Jude trial of the Amplatzer device in the PFO setting is ongoing in Europe--the PC Trial. Gore also has a device under investigation for this indication, its Helex septal occluder being studied in the randomized REDUCE study.


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.