Atrial Mechanics in Heart Failure With Preserved Ejection Fraction: Effect of a No-Implant Interatrial Shunt.

BACKGROUND

The atria play an important role in the pathophysiology of heart failure with preserved ejection fraction. Decreased left atrial strain is associated with worse clinical outcomes. The impact of no-implant interatrial shunting on atrial structure and function has not been described.

METHODS

We characterized the left atrial (LA) and right atrial strain-pressure relationship at rest and during exercise, before and after creation of a no-implant interatrial shunt. We included patients with New York Heart Association class II, III, or ambulatory IV heart failure with a left ventricular ejection fraction ≥40% and elevated LA wedge pressure during supine ergometry (≥25 mm Hg). Exercise hemodynamics and echocardiographic measurements were analyzed at baseline, 1 month and 6 months (echo only) following transcatheter, transeptal creation of a 7 mm no-implant interatrial shunt.

RESULTS

A total of 33 patients were enrolled/included in the study. At 1 month, LA pressure at rest was significantly reduced from 19.7±7.0 to 17.2±5.0 mm Hg (P=0.044), and from 39.7±10.5 to 33.6±11.1 mm Hg (P=0.002) during exercise. Reductions in LA pressure were associated with a mean decrease of 55.4 mm Hg/W·kg in LA work (P<0.001). Echo measurements demonstrated significant improvements in LA reservoir strain of +4.0% (P=0.015) and +4.1% (P=0.046) at 1 and 6 months, respectively. Modest improvements were observed in LA conduit and contractile strain, with a similar overall trend in right atrial strain measurements. These findings were associated with a significant reduction in LA volumes and an increase in right atrial volume. There was no change in right atrial pressure or measures of right ventricular function.

CONCLUSIONS

Hemodynamic and strain assessment in patients with heart failure with preserved ejection fraction suggests that a no-implant interatrial shunt can significantly improve the pressure-function relationship of the LA.

REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifiers: NCT04583527, NCT04838353, and NCT05501652.