6.2 Interventional Strategies for HFrEF: Shunt the Atrium or Squeeze the Muscle(s)?

Problem Presenter: Steve Bailey

These proceedings summarize the educational activity of the 18th Biennial Meeting of the International Andreas Gruentzig Society held January 27 to 30, 2026, in Puerto Ayora, Santa Cruz, Ecuador.

Faculty Disclosures     Sponsors

2026 IAGS Summary Document

Statement of problem or issue

Heart failure with reduced ejection fraction (HFrEF) continues to be a serious clinical problem. While optimal medical therapy for HFrEF has been shown to improve outcomes, the 5-year mortality rate remains very high at 50%-75%.[1,2] This is partly due to overall low use of optimal medical therapy after hospitalization for heart failure.[3] There are several non-pharmacologic therapies (ie, devices) which may help improve outcomes in HFrEF patients, and this subject area is under active investigation presently.

Gaps in current knowledge

Hemodynamic information has been shown to be useful in identifying and classifying HFrEF patients and guiding their management.[4,5] A recent meta-analysis of pooled, patient-level data from three randomized trials of implantable hemodynamic monitors (pulmonary artery or left atrial pressure) demonstrated lower mortality and fewer heart failure hospitalizations in patients with implantable monitors compared to control patients.[6] However, this remains a large knowledge gap area, since the precise hemodynamic parameters of greatest utility are not known.

• • Knowledge Gap: What do we need to treat, and how?
    • Afterload
    • Preload
    • Contractility
    • Myocardial Stress/Strain
    • Cardiopulmonary Coupling
    • Resting state alone, or Rest/Exercise

Possible solutions or future directions

An overview of device therapy for HFrEF is shown below:

• Cardiac resynchronization (CRT)
  • Adaptive CRT (aCRT)
  • Endocardial CRT systems (WiSE-CRT)
• Neuromodulation
  • Baroreflex
  • Vagus nerve
• Remote monitoring / Implantable sensors
  • CardioMems
  • Heartlogic
  • Corvu
• Regenerative and bioelectronic devices
  • Stem-cell scaffolds
  • Bioelectronic patches
  • Microelectronic muscle stimulators
  • Synchronized diaphragmatic stimulation
  • Bioelectronic mesh
  • Heart on a Chip
• Cardiac contractility modulation (CCM)
  • Impulse Dynamics
• Left ventricular unloading & circulatory support devices
  • Implantable left atrial shunt
  • Interatrial flow regulator
  • Partial mechanical LV unloading (Synergy pump)
• Interatrial and pericardial decompression devices
  • Parachute device
  • AccuCinch

Two recent studies of atrial (inter-atrial) shunting have yielded important insights. First, in the RELIEVE-HF trial, atrial shunting did not improve clinical outcomes overall.[7] However, in an exploratory analysis, shunting did improve outcomes in patients with HFrEF, but was associated with worse outcomes in patients with HFpEF.[7]

Second, in the REDUCE-LAP II trial, atrial shunting in patients with LVEF≥40% was associated with reverse LV remodeling over 2 years.[8] A cluster of variables were identified consistent with existence of responder and non-responder phenotypes. Changes in cardiac structure and function were more favorable in responders compared to non-responders. Future directions will include both improving adoption of optimal medical therapies, and investigating and then applying various devices.

References

1. Rao VN, et al. Optimal Medical Therapy and Outcomes Among Patients With Chronic Heart Failure With Reduced Ejection Fraction. JACC Heart Fail. 2024;12(11):1862-1875. doi: 10.1016/j.jchf.2024.05.026. Epub 2024 Aug 7. PMID: 39115518.
2. Bozkurt B, et al; WRITING COMMITTEE MEMBERS. HF STATS 2024: Heart Failure Epidemiology and Outcomes Statistics An Updated 2024 Report from the Heart Failure Society of America. J Card Fail. 2025;31(1):66-116. doi: 10.1016/j.cardfail.2024.07.001. Epub 2024 Sep 24. PMID: 39322534.
3. Shoji S, et al. Guideline-Directed Medical Therapy After Hospitalization for Acute Heart Failure: Insights From the CONNECT-HF. J Am Heart Assoc. 2024;13(24):e036998. doi: 10.1161/JAHA.124.036998. Epub 2024 Dec 10. PMID: 39655748.
4. Kramer DG, et al. Quantitative evaluation of drug or device effects on ventricular remodeling as predictors of therapeutic effects on mortality in patients with heart failure and reduced ejection fraction: a meta-analytic approach. J Am Coll Cardiol. 2010;56(5):392-406. doi: 10.1016/j.jacc.2010.05.011. PMID: 20650361.
5. Rajagopalan N, et al. Practical Guidance for Hemodynamic Assessment by Right Heart Catheterization in Management of Heart Failure. JACC Heart Fail. 2024;12(7):1141-1156. doi: 10.1016/j.jchf.2024.03.020. PMID: 38960519.
6. Lindenfeld J, et al; GUIDE-HF, CHAMPION, and LAPTOP-HF Investigators. Implantable Hemodynamic Monitors Improve Survival in Patients With Heart Failure and Reduced Ejection Fraction. J Am Coll Cardiol. 2024;83(6):682-694. doi: 10.1016/j.jacc.2023.11.030. PMID: 38325994.
7. Stone GW, et al; RELIEVE-HF Investigators. Interatrial Shunt Treatment for Heart Failure: The Randomized RELIEVE-HF Trial. Circulation. 2024;150(24):1931-1943. doi: 10.1161/CIRCULATIONAHA.124.070870. Epub 2024 Sep 23. PMID: 39308371.
8. Patel RB, 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. 2024 Jun 1;9(6):507-522. doi: 10.1001/jamacardio.2024.0520. PMID: 38630494.