Pioneering HHS researcher targets strokes before they happen
Two international studies led by renowned Hamilton Health Sciences (HHS) heart surgeon and researcher Dr. Richard Whitlock could prevent life-threatening strokes, after performing a simple add-on procedure during heart surgery.
Both studies focus on preventing stroke in patients who are at risk of developing atrial fibrillation after surgery. Atrial fibrillation is a heart rhythm disorder where the upper chambers of the heart beat irregularly, causing them to be out-of-sync with the lower chambers.
“Here in Hamilton we’re performing research that alters medical practice worldwide.” — Dr. Richard Whitlock
Whitlock is a senior scientist with the Population Health Research Institute (PHRI), a joint institute of HHS and McMaster University and a world leader in heart and stroke health research. PHRI is a key collaborator in both trials, with American-based medical device company AtriCure as the sponsor. AtriCure devices are being used in both trials, as part of Whitlock’s ongoing research aimed at improving cardiovascular surgical outcomes worldwide through leading-edge investigations.
Giant LEAAPS
In July, the LEAAPS (Left Atrial Appendage Exclusion for Prophylactic Stroke Reduction) led by Whitlock will finish recruiting 6,500 patients globally, including over 430 HHS patients. LEAAPS is one of the world’s largest trials in surgical intervention during cardiac surgery.
All trial participants were found through medical tests to be at increased risk of atrial fibrillation and stroke. And all were already undergoing heart surgery for other reasons and agreed to also have the trial’s additional, potentially preventative procedure during their surgery.
For this trial, surgeons use AtriCure’s AtriClip, a tiny clamp for sealing off a part of the heart where dangerous clots might form. By closing off the left atrial appendage, the goal is to help lower the risk of stroke or blood clots in people at increased risk of developing atrial fibrillation.
“The LEAAPS trial seeks to show that we can reduce stroke risk in almost 60 per cent of patients already having heart surgery for other reasons, by also occluding the heart’s left atrial appendage,” says Whitlock, adding that recruitment for this study started in 2023 and will finish in July, almost two years earlier than anticipated.
The LEAAPs trial builds on earlier findings from a groundbreaking international study also led by Whitlock called LAAOS III, which spanned nine years and finished in 2021. It found that sealing off the heart’s left atrial appendage during heart surgery can help prevent strokes in people with atrial fibrillation.
A different kind of heart burn
Meanwhile, Whitlock’s BoxX-NoAF trial is gearing up to recruit 1,000 patients internationally, including 150 from HHS for a preventative measure performed during heart surgery, taking place for other reasons, to stop the development atrial fibrillation as a post-surgical complication in patients with no history of this disorder.
For this trial, surgeons perform box-lesion ablation, where a high-frequency electrical current is used to safely burn a line around the area of the heart that can trigger atrial fibrillation, creating a `box’ of scar tissue that keeps the heart beating normally by blocking faulty signals that trigger an irregular heartbeat. The specialized surgical instrument used for this procedure is AtriCure’s Isolator Synergy EnCompass Clamp.
“Our goal is to show that with patients who don’t yet have atrial fibrillation — but have shown on an ultrasound that they’re on the pathway to getting it — we can stop that pathway.”
Whitlock’s work speaks to the world-leading research happening in Hamilton, where cutting-edge discoveries are benefiting patients locally and worldwide. And since this research is happening here at HHS, our region’s patients are often the first to benefit from innovative new treatments.
“Here in Hamilton we’re performing research that alters medical practice worldwide,” says Whitlock.
