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NEW ORLEANS -- A novel inter-atrial septal shunt implanted in heart failure patients to reduce left atrial pressure demonstrated efficacy 1 year, according to the late-breaking REDUCE LAP-HF study presented here.

One year after transcatheter shunt placement, individuals with heart failure with preserved ejection fraction (HFpEF) maintained improvements demonstrating the clinical efficacy of the device:

• Patients moved to New York Heart Association class I or II (P<0.001)
• Quality of life was boosted by 15 points on the Minnesota Living with Heart Failure questionnaire on average (P<0.001)
• Device recipients gained 33 meters in the 6 minute walk test (P<0.01).

Those who got the device had a death rate of 4.7% and a stroke frequency of 1.5%, , of Alfred Hospital in Australia, reported during the annual American Heart Association meeting. The REDUCE LAP-HF study was simultaneously published online in .

"The clinical and hemodynamic benefit observed 6 months after implant was sustained through 1 year, with no evidence of adverse sequelae," Kaye concluded, citing 6 month results that had been published previously in .

A computer model suggested that a 8 mm inter-atrial shunt would provide left atrial decompression during exercise, cutting off pulmonary venous hypertension and the ensuing pulmonary congestion and dyspnea.

In total, 64 patients with HFpEF and elevated pulmonary capillary wedge pressure -- indicating high left atrial pressure at rest and during exercise -- were given the inter-atrial septal shunt.

Echocardiographic data found that at 1 year, there was no change in left ventricular (LV) ejection fraction or atrial volumes from baseline. Rather, there was an increase in right ventricular (RV) ejection fraction; a reduction in LV end-diastolic volume index; and an uptick in RV end-diastolic volume index.

When patients were at rest, invasive hemodynamic monitoring revealed no difference in right atrial pressure, mean pulmonary artery pressure, and wedge pressure -- but an increase in cardiac output (5.2 at baseline versus 6.7 at 1 year, P<0.01). Cardiac output remained elevated during exercise; exercise time and workload were also boosted 1 year after shunt implantation.

"Based on the limited follow-up data available, there does not seem to be a marked change in echo, exercise, or hemodynamic parameters between 6 and 12 months," concluded discussant Nancy Sweitzer, MD, PhD, of University of Arizona in Tucson.

"In the 75% of patients evaluated, device flow remains left to right in all," she also commented at AHA, easing concerns over the long-term effects of chronic elevation in right-sided output.

Then again, hemodynamic evaluation was performed on a fairly small subset of patients, she noted; Kaye's non-randomized, open-label device trial had potential for bias.

Furthermore, other studies such as RELAX and MIRACLE -- as well as the first cardiac resynchronization therapy report -- reported that even a control group got boosts in self-reported quality of life and the 6 minute walk test just by virtue of being enrolled.

But Sweitzer conceded that the magnitude of improvement seen in REDUCE LAP-HF appears real and more than just a placebo effect.

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