The use of durable mechanical support, such as VADs, is a significant but often underutilized treatment for advanced heart failure (HF) patients. Despite advancements in medical therapy for stage C HF patients, survival rates for advanced HF remain under 20% at 5 years. In this context, VADs have become a substantial treatment option to improve both quality of life and survival for these patients.

This review provides a detailed and updated view on VAD use, analyzing indications, timing of referral, patient selection, surgical considerations, knowledge gaps, and future directions.

COMMENTARY:

The purpose of this blog entry is to summarize the key points from this document:

– Survival outcomes, adverse effects, and quality of life.

Innovations in VAD technology have reduced adverse event risk. Currently, the average survival rate for patients with a VAD is similar to heart transplant survival at 3 years, with a 5-year survival rate close to 60%. However, adverse events remain significant. Only 30% of patients are free from hospitalization in the first year post-implant. Among adverse event types, stroke and infection carry the highest mortality risk. One of the most common complications associated with VAD is mucocutaneous bleeding, affecting approximately 25-30% of patients during the first year after implantation. This phenomenon is due to vascular changes in response to continuous pump flow, acquired von Willebrand syndrome, and the combination of dual therapy with anticoagulants and antiplatelet agents. A recent study (ARIES HM3) demonstrated safety and bleeding reduction by excluding aspirin from the antithrombotic regimen in VAD patients.

In addition to prolonging survival, VAD aims to improve patient quality of life. The MOMENTUM 3 study showed significant improvements in health-related quality of life post-VAD implantation. Most patients (95%) who received the HeartMate 3 VAD in the study were in NYHA functional class IV before implantation. Of these, 77% improved to functional class I or II at 6 months, with these results remaining consistent up to 24 months.

– Implant Indications.

Despite multiple parameters, predicting events in advanced HF patients remains challenging, and they are often referred too late to specialized centers. Several relevant clinical findings help identify these patients. Ultimately, patients with persistent HF symptoms despite optimal medical treatment, with severely reduced left ventricular ejection fraction (LVEF) and significantly impaired functional capacity, should be immediately referred to a heart failure program for invasive option assessment. The American Heart Association recommends VAD therapy in advanced HF patients with severely reduced LVEF in NYHA functional class IV who depend on inotropes or short-term ventricular support (recommendation IA). For patients not dependent on inotropes or short-term support, the recommendation is IIaB.

Traditionally, VAD use has been categorized into several strategies: bridge to transplant, bridge to decision/candidacy, bridge to recovery, and destination therapy. In recent years, there has been a significant increase in VAD implantation for destination therapy, covering approximately 81% of patients, while its use as a bridge to transplant has substantially declined, representing about 5% of patients.

– Patient Selection.

Before VAD implantation, a multiorgan assessment of the patient’s progression is necessary. Irreversible organ damage (neurological, renal, or hepatic) is considered an absolute contraindication. Age should also be considered. Unlike transplantation, there is no age limit for VAD implantation. Although advanced age could be seen as a relative contraindication, an INTERMACS analysis showed that 4.8% of VAD recipients between 2010 and 2020 were over 75. Recent studies show that VAD implantation in the elderly is associated with functional capacity and quality-of-life improvements similar to those in younger patients.

Regarding obesity, it is not an absolute contraindication, though each center sets its limits. However, large registry data indicate obesity is associated with higher mortality and morbidity.

Right ventricular dysfunction is a significant cause of morbidity and premature mortality post-VAD implantation. Predicting the risk of right ventricular dysfunction remains a challenge. Risk scores combining clinical and hemodynamic profile variables exist, but none has positioned itself as a standard model.

– Surgical Considerations.

Key points in VAD implantation include aligning the inflow cannula from the left ventricular apex with the mitral valve; suturing the outflow cannula in the greater curvature of the ascending aorta at an angle to minimize aortic insufficiency; and tunneling the percutaneous cable through the rectus muscle of the upper abdominal wall before exiting the upper left or right quadrant.

Although median sternotomy is the most common approach for VAD implantation, an anterolateral thoracotomy approach has emerged as an alternative with certain advantages, particularly preserving the geometry of the right ventricle. The ongoing SWIFT study investigates various non-median sternotomy approaches. Preliminary results show no significant differences in hospital stay, transfusion needs, adverse effects, or quality of life between sternotomy and thoracotomy approaches.

When managing valve disease during these implantations, each valve must be approached specifically. While moderate or severe aortic valve insufficiency generally requires repair or replacement, some controversy remains about handling other valves. Recent study data suggest that correcting significant tricuspid valve insufficiency does not necessarily reduce the incidence of right ventricular dysfunction after VAD implantation. Similarly, mitral valve insufficiency raises questions, as recent MOMENTUM 3 study results indicate that preoperative mitral insufficiency decreased significantly in patients following VAD implantation.

– Knowledge Gaps and Future Directions.

Despite technological advances and improved outcomes over the last two decades, VAD use requires adjustments for widespread adoption in advanced HF patients. One area needing reconsideration is improving the use of these devices as adjunctive therapy to heart transplantation and identifying transplant candidates with myocardial recovery potential who could benefit from VADs to delay or avoid transplantation. Additionally, enhancing both quality of life and survival by synergistically combining a device with heart transplantation in a single patient, especially in younger patients, is essential.

Goals have been set to maximize patient benefit, and if implemented and streamlined, these advancements could double the significant progress achieved so far. These developments include improvements in patient and caregiver education, adverse event reduction, and technological advances in devices. With these actions, VAD use is expected to expand as awareness of contemporary mechanical support outcomes grows and device innovation advances.

Undoubtedly, the advent of continuous axial flow systems, along with the growing experience of teams—often compelled by the increasingly frequent donor shortages—has propelled this therapy’s promising path forward. Consensus documents like this one represent a recap of our current knowledge and, more importantly, what we need to know to make it a more widely used therapy. The history of VAD systems marks a milestone in medicine, with our specialty holding an undeniable prominence, and its story continues to be written today.

REFERENCE:

Tedford RJ, Leacche M, Lorts A, Drakos SG, Pagani FD, Cowger J. Durable Mechanical Circulatory Support: JACC Scientific Statement. J Am Coll Cardiol. 2023 Oct 3;82(14):1464-1481. doi: 10.1016/j.jacc.2023.07.019.