The concept is deceptively simple. A soft robotic sleeve is positioned around the surface of the heart and uses compliant actuators to reproduce or assist the squeezing motion of cardiac muscle. Instead of forcing blood through the body with a rotating impeller, as ventricular assist devices do, the sleeve aims to support the heart’s own pumping action from the outside. Depending on the design, its artificial muscles may be driven by pneumatic pressure, hydraulic fluid, cables, shape-changing materials or other mechanisms that generate controlled contraction.

That softness is central to the technology’s appeal. The human heart changes shape continuously as it fills and ejects blood, while its surface is delicate, wet and constantly moving. A rigid device can impose damaging pressure or interfere with natural motion. Soft robots, by contrast, can conform to curved biological structures and distribute forces over a larger area. In principle, a cardiac sleeve could provide assistance without placing a rotating pump inside the bloodstream, potentially reducing complications associated with blood-contacting components such as clot formation and bleeding.

The review by Foroughi, Nazari, Lovell and colleagues examines why that promise has not yet translated into widespread clinical use. One of the hardest engineering problems is synchronisation. The device must respond to the heart’s electrical and mechanical activity with precise timing, assisting contraction without obstructing relaxation or filling. If the sleeve squeezes too early, too late or too forcefully, it could reduce cardiac output rather than improve it. Reliable sensing systems will therefore be needed to detect the heart’s phase of activity and adjust assistance beat by beat.

The heart is also not a uniform pump. Its ventricles, atria and great vessels have different shapes and roles, and the geometry of a failing heart can vary substantially from one patient to another. A sleeve designed around a healthy anatomical model may fit poorly on a dilated or scarred heart. Uneven contact could create concentrated stresses, restrict coronary blood flow or injure surrounding tissue. The review highlights the importance of patient-specific designs, adaptable structures and carefully controlled force transmission if these devices are to work safely across diverse forms of heart failure.

Power and control present another obstacle. Pneumatic and hydraulic systems can generate strong, smooth actuation, but they may require external pumps, tubing and reservoirs that limit mobility and complicate implantation. Electrical systems can be more compact, yet they introduce questions about heat, battery life, insulation and long-term reliability. Every connector, sensor and moving component adds a potential failure point. A clinically useful sleeve must operate continuously for months or years, not merely survive short laboratory demonstrations.

Biocompatibility and surgical practicality are equally important. Any implant placed around the heart must resist inflammation, infection and tissue adhesion while remaining mechanically stable. Surgeons would need to position it without damaging the myocardium, coronary vessels or nearby organs. The device must also be removable or adjustable if a patient’s condition changes. Materials that perform well in benchtop tests may behave differently inside the body, where they encounter body fluids, immune responses, repeated mechanical loading and limited space.

The paper places these engineering questions within the wider challenge of clinical translation. Demonstrating that a sleeve can make a model heart beat more effectively is only an early milestone. Researchers must establish safety, durability and meaningful improvements in circulation through carefully designed animal studies and human trials. They will also need to define which patients are most likely to benefit: people awaiting transplantation, patients recovering from temporary cardiac injury, or those with chronic heart failure who are not candidates for conventional mechanical pumps. Regulatory approval will depend on evidence that benefits outweigh surgical and device-related risks.

Soft robotic cardiac sleeves therefore occupy an intriguing middle ground between biological repair and mechanical replacement. They do not attempt to rebuild damaged heart muscle, but they may provide external assistance while preserving more of the organ’s natural function. The review suggests that progress will depend on collaboration among roboticists, cardiologists, surgeons, materials scientists and rehabilitation specialists. If designers can solve synchronisation, anatomical fit, power delivery and long-term safety, an external robotic muscle could eventually become a new tool against heart failure. For now, however, the technology remains a compelling research frontier rather than a ready-made clinical cure.

Subject of Research: Soft robotic cardiac sleeves for assisting heart function in heart failure.

Article Title: Clinical translation and engineering challenges of soft robotic cardiac sleeves for heart failure.

Article References: Foroughi, J., Nazari, H., Lovell, N. et al. “Clinical translation and engineering challenges of soft robotic cardiac sleeves for heart failure.” Nature Communications 17, 8254 (2026). https://doi.org/10.1038/s41467-026-76596-z

Image Credits: AI Generated

DOI: https://doi.org/10.1038/s41467-026-76596-z

Keywords: soft robotics, cardiac sleeves, heart failure, cardiac assist devices, biomedical engineering, medical robotics, mechanical circulatory support, clinical translation

Heart failure with preserved ejection fraction (HFpEF) and mildly reduced ejection fraction (HFmrEF) present distinct pathophysiological challenges. Unlike traditional heart failure where the heart’s pumping capacity is markedly diminished, HFpEF patients maintain an ejection fraction above 50%. Here, the cardiac muscle contracts adequately but exhibits impaired relaxation during diastole, leading to inefficient ventricular filling. HFmrEF, characterized by ejection fractions between 41% and 49%, occupies a nuanced space between preserved and reduced function, with clinical profiles and treatment implications that are only recently being elucidated through emerging research.

The AHA’s new three-year quality improvement initiative, named IMPLEMENT-EF, seeks to systematically dissect and address these complexities. By mapping deficiencies in the patient journey and care delivery models, the initiative strives to delineate optimal management strategies and foster consistent application of evidence-based therapies. Using robust data obtained from the AHA’s Get With The Guidelines® – Heart Failure registry, it will leverage real-world clinical insights to refine treatment paradigms and disseminate best practices across care settings nationwide.

Central to the initiative is the mobilization of multidisciplinary care teams. Recognizing that effective management of HFpEF and HFmrEF transcends conventional cardiology, the program incorporates pharmacists, nurses, and allied health professionals as integral collaborators. This team-based approach emphasizes early identification of at-risk individuals, prompt initiation of scientific, protocol-driven treatments, and ongoing patient support to ensure adherence and optimal health outcomes.

Ejection fraction, the clinical metric pivotal to this initiative, quantifies the proportion of blood ejected from the left ventricle per heartbeat. Normal EF ranges from 55% to 70%, serving as a benchmark for cardiac performance. In patients with HFpEF, the heart’s impaired relaxation compromises ventricular filling without undermining contraction strength, posing diagnostic and therapeutic conundrums. Conversely, HFmrEF reflects a mildly diminished pump function, linking pathophysiology more closely to traditionally studied heart failure phenotypes, but still demanding tailored treatment strategies.

Pharmacological treatment innovations for HFpEF and HFmrEF are burgeoning but remain underutilized. The initiative aims to expedite translation of cutting-edge therapies—including novel agents such as sodium-glucose cotransporter 2 (SGLT2) inhibitors and mineralocorticoid receptor antagonists—into clinical practice by educating providers and fostering rigorous treatment adherence. This effort is anticipated to mitigate morbidity and improve quality of life for millions grappling with these heart failure subtypes.

One of the distinctive features of IMPLEMENT-EF is its emphasis on education and knowledge dissemination. The initiative will deploy an array of professional learning modalities, from interactive eLearning modules and live expert presentations to an innovative podcast series featuring thought leaders in cardiology. These resources are designed to elevate provider competence and confidence, thereby enhancing clinical decision-making and patient management efficacy.

Supporting the educational framework, a dedicated Science Advisory Panel of renowned experts will oversee content development and ensure the integrity and currency of the materials. This panel’s guidance guarantees that frontline clinicians receive the most authoritative and up-to-date information, facilitating the adoption of evidence-based interventions throughout diverse healthcare environments.

Underpinning this ambitious endeavor is collaborative synergy with Bayer, whose support enables the recruitment of 40 hospitals to participate in the program’s inaugural phase. These sites will serve as hubs for knowledge exchange, peer collaboration, and pilot testing of quality improvement models. This experiential learning environment fosters innovation and facilitates scaling of successful interventions to broader healthcare systems, maximizing the initiative’s impact.

The urgency of addressing HFpEF and HFmrEF cannot be overstated. Unlike HFrEF, where decades of research have propelled treatment advances, the lingering knowledge gaps in these subtypes have contributed to stagnant outcomes. IMPLEMENT-EF aims to catalyze progress by infusing data-driven strategies, multidisciplinary cooperation, and targeted education into everyday care delivery, ultimately transforming the prognosis for millions afflicted by these insidious forms of heart failure.

Dr. Mariell Jessup, chief science and medical officer at the AHA, encapsulated the initiative’s vision by emphasizing the necessity of a coordinated, team-based approach. She highlighted how integrating diverse expertise and leveraging real-world data will not only elevate care quality but also forge scalable, replicable models that can be disseminated nationally to benefit broad patient populations.

Similarly, Robert Perkins, vice president of U.S. medical affairs for cardiovascular and renal at Bayer, expressed corporate commitment to advancing translational science in cardiovascular medicine. His remarks underscored the partnership’s shared goal of bridging gaps in evidence and expanding access to innovative, effective treatments for HFpEF and HFmrEF patients.

As this initiative unfolds, the medical community and patients alike are encouraged to stay informed through the AHA’s dedicated portal, HEART.org/IMPLEMENTEF. This resource will provide ongoing updates, insights, and tools emanating from the program’s unfolding progress, fostering transparency and community engagement in this vital quest to reshape heart failure care.

In sum, the American Heart Association’s IMPLEMENT-EF initiative represents a crucial advancement in addressing the unmet needs of heart failure patients with preserved and mildly reduced ejection fractions. By uniting data analytics, multidisciplinary collaboration, and professional education under one ambitious umbrella, the program promises to chart a new course toward improved survival, reduced symptoms, and enhanced quality of life for millions confronting these complex cardiac conditions.

Subject of Research: Heart failure with preserved and mildly reduced ejection fraction (HFpEF and HFmrEF) treatment and care improvement.

Article Title: American Heart Association Launches IMPLEMENT-EF, an Innovative Initiative to Transform Care for HFpEF and HFmrEF Patients.

News Publication Date: September 15, 2025.

Web References:

• https://www.heart.org/en/professional/quality-improvement/IMPLEMENT-EF
• https://www.heart.org/en/professional/quality-improvement/get-with-the-guidelines/get-with-the-guidelines-heart-failure
• https://www.heart.org/en/health-topics/heart-failure/what-is-heart-failure

References:

1. Savarese G, Stolfo D, Sinagra G, Lund L. Heart failure with mid-range or mildly reduced ejection fraction. Nat Rev Cardiol. 2022;19:100–116.
2. Shah S, Kitzman D, et al. Phenotype-Specific Treatment of Heart Failure With Preserved Ejection Fraction: A Multiorgan Roadmap. Circulation. 2016;134(1).
3. Shah K, Xu H, Matsouaka R, et al. Heart Failure With Preserved, Borderline, and Reduced Ejection Fraction: 5-Year Outcomes. JACC. 2017 Nov;70(20):2476–2486.
4. Kapelios CJ, Shahim B, Lund LH, Savarese G. Epidemiology, Clinical Characteristics and Cause-specific Outcomes in Heart Failure with Preserved Ejection Fraction. Cardiac Failure Review. 2023;9:e14.

Keywords: Heart Failure, HFpEF, HFmrEF, Ejection Fraction, Cardiovascular Care, Multidisciplinary Teams, Quality Improvement, Evidence-Based Therapies, Patient Outcomes, American Heart Association, IMPLEMENT-EF, Pharmacological Therapy.