Atrial Shunt Devices may Redefine Heart Failure Management: JAMA

The post hoc analysis of REDUCE LAP-HF II Randomized Clinical Trial sheds light on the long-term effect of an atrial shunt device on cardiac structure and function in patients with heart failure and preserved or mildly reduced ejection fraction.

The study findings published in JAMA Cardiology showed no evidence of right ventricle (RV) dysfunction over the initial two years and supported the previously identified responder group hypothesis.

"The post hoc analysis of the REDUCE LAP-HF II RCT comprising 621 patients found that atrial shunting led to reverse remodeling of left-sided chambers and increases in volume of right-sided chambers but no change in RV systolic function compared with sham," the researchers wrote.

They found changes in cardiac function/structure to be favorable in previously defined responders versus the nonresponders.

The results of the REDUCE LAP-HF II trial were neutral overall, however, atrial shunt therapy demonstrated potential efficacy in responders (no latent pulmonary vascular disease and no cardiac rhythm management device). Therefore, Ravi B. Patel, Northwestern University Feinberg School of Medicine, Chicago, Illinois, and colleagues aimed to evaluate the effect of atrial shunt vs sham control on cardiac structure/function in the overall study and stratified by responder status.

For this purpose, the researcher conducted a sham-controlled randomized clinical trial of an atrial shunt device in HFpEF/HFmrEF. Trial participants with evaluable echocardiography scans were recruited from 89 international medical centers.

The outcome measures were changes in echocardiographic measures from baseline to 1, 6, 12, and 24 months after the index procedure.

The modified intention-to-treat analysis of the REDUCE LAP-HF II trial comprised 621 randomized patients with a median age of 72.0 years; 61.5% were females; shunt arm, 309; sham control arm, 312.

The researchers reported the following findings:

• Through 24 months, 98% of patients in the shunt arm with evaluable echocardiograms had patent shunts.
• In the overall trial population, the shunt reduced left ventricular (LV) end-diastolic volume (mean difference, −5.65 mL), left atrial (LA) minimal volume (mean difference, −2.8 mL), and improved LV systolic tissue Doppler velocity (mean difference, 0.69 cm/s) and LA emptying fraction (mean difference, 1.88 percentage units) compared with sham.
• Shunt treatment also increased right ventricular (RV; mean difference, 9.58 mL) and right atrial (RA; mean difference, 9.71 mL) volumes but did not affect RV systolic function, pulmonary artery pressure, or RA pressure compared with sham.
• In the shunt arm, responders had smaller increases in RV end-systolic volume (mean difference, 1.58 mL versus 7.89 mL), RV end-diastolic volume (mean difference, 5.71 mL vs 15.18 mL), and RV/LV ratio (mean difference, 0.07 vs 0.20) and a larger increases in transmitral A wave velocity (mean difference, 5.08 cm/s vs −1.97 cm/s) compared with nonresponders randomized to the shunt, suggesting a greater ability to accommodate shunted blood through the pulmonary circulation enabling LA unloading.

In conclusion, the analysis showed that atrial shunting led to reverse remodeling of left-sided chambers and increases in right-sided chamber volume consistent with the shunt flow but no change in RV systolic function compared with sham.

"Changes in cardiac function/structure were more favorable in responders versus nonresponders treated with the shunt, supporting the previously identified responder group hypothesis and mechanism, although there is a need for further evaluation with longer follow-up," the researchers wrote.

Reference:

Patel RB, Silvestry FE, Komtebedde J, et al. Atrial Shunt Device Effects on Cardiac Structure and Function in Heart Failure With Preserved Ejection Fraction: The REDUCE LAP-HF II Randomized Clinical Trial. JAMA Cardiol. Published online April 17, 2024.  doi:10.1001/jamacardio.2024.0520