Outcomes in Smaller Body Size Adults after HeartMate 3 Left Ventricular Assist Device Implantation

Left Ventricular Dimensions and Clinical Outcomes With a Fully Magnetically Levitated Left Ventricular Assist Device

BACKGROUND

Prior analyses have suggested that a smaller left ventricular end-diastolic diameter (LVEDD) is associated with reduced survival following HeartMate 3 left ventricular assist device implantation.

OBJECTIVES

In this trial-based comprehensive analysis, the authors sought to examine clinical characteristics and association with the outcome of this specific relationship.

METHODS

The authors analyzed the presence of LVEDD <55 mm among 1,921 analyzable HeartMate 3 patients within the MOMENTUM 3 (Multicenter Study of MagLev Technology in Patients Undergoing Mechanical Circulatory Support Therapy With HeartMate 3) trial portfolio, on endpoints of overall survival and adverse events at 2 years. Adverse events included hemocompatibility-related (stroke, bleeding, and pump thrombosis) and non-hemocompatibility-related (right heart failure, infection) outcomes.

RESULTS

Those with a smaller LVEDD (<55 mm) (n = 108) were older (age 63 ± 11 years vs 60 ± 12 years; P = 0.005), were more often female (31% vs 20%; P = 0.096), and had more ischemic cardiomyopathy (60.2% vs 42.6%; P = 0.0004) compared with the LVEDD ≥55 mm group (n = 1,813). Death during implant hospitalization was higher (14.8 vs 5.7%; P = 0.0007) and survival at 2 years was lower (63.3% vs 81.8%; HR: 1.97 [95% CI: 1.39-2.79]; P = 0.0002) in the LVEDD <55 mm group. The LVEDD <55 mm group experienced more deaths due to hemocompatibility-related adverse events (2.8% vs 0.6%; HR: 4.61 [95% CI: 1.29-16.45]; P = 0.018) and right heart failure, both early (0-30 days; 7.4% vs 2.0%; HR: 3.70 [95% CI: 1.73-7.91]; P = 0.001) and late (>30 days; 12.0 vs 4.8%; HR: 2.58 [95% CI: 1.37-4.84]; P = 0.003). Low-flow alarms rehospitalizations were higher in the LVEDD <55 mm cohort (17.4 vs 8.3%; HR: 2.39 [95% CI: 1.59-3.59]; P < 0.001).

CONCLUSIONS

Although infrequent in occurrence, smaller LVEDD (<55 mm) is associated with increased risk for early and late mortality, a consequence of hemocompatibility-related and right heart failure-related deaths. Rehospitalizations due to low-flow alarms are also more frequent. (MOMENTUM 3 IDE Clinical Study Protocol [HM3™]; NCT02224755; MOMENTUM 3 Continued Access Protocol [MOMENTUM 3 CAP]; NCT02892955).

Anatomical compatibility of a novel total artificial heart: An in-silico study

BACKGROUND

ShuttlePump is a novel total artificial heart (TAH) recently introduced to potentially overcome the limitations associated with the current state-of-the-art mechanical circulatory support devices intended for adults. In this study, we adapted the outflow cannulation of the previously established ShuttlePump TAH and evaluated the anatomical compatibility using the virtual implantation technique.

METHODS

We retrospectively assessed the anatomical compatibility of the ShuttlePump using virtual implantation techniques within 3D-reconstructed anatomies of adult heart failure patients. Additionally, we examined the impact of outflow cannula modification on the hemocompatibility of the ShuttlePump through computational fluid dynamic simulations.

RESULTS

A successful virtual implantation in 9/11 patients was achieved. However, in 2 patients, pump interaction with the thoracic cage was observed and considered unsuccessful virtual implantation. A strong correlation (r <-0.78) observed between the measured anatomical parameters and the ShuttlePump volume exceeding pericardium highlights the importance of these measurements apart from body surface area. The numerical simulation revealed that the angled outflow cannulation resulted in a maximum pressure drop of 1.8 mmHg higher than that of the straight outflow cannulation. With comparable hemolysis index, the shear stress thresholds of angled outflow differ marginally (<5%) from the established pump model. Similar washout behavior between the pump models indicate that the curvature did not introduce stagnation zone.

CONCLUSION

This study demonstrates the anatomic compatibility of the ShuttlePump in patients with biventricular failure, which was achieved by optimizing the outflow cannulation without compromising hemocompatibility. Nevertheless, clinical validation is critical to ensure the clinical applicability of these findings.

Circulatory Support: Artificial Muscles for the Future of Cardiovascular Assist Devices

Artificial muscles enable the design of soft implantable devices which are poised to transform the way we mechanically support the heart today. Heart failure is a prevalent and deadly disease, which is treated with the implantation of rotary blood pumps as the only alternative to heart transplantation. The clinically used mechanical devices are associated with severe adverse events, which are reflected here in a comprehensive list of critical requirements for soft active devices of the future: low power, no blood contact, pulsatile support, physiological responsiveness, high cycle life, and less-invasive implantation. In this review, prior art in artificial muscles for their applicability in the short and long term is investigated and critically evaluated. The main challenges regarding the effectiveness, controllability, and implantability of recently proposed actuators are highlighted and the future perspectives for attachment, physiological responsiveness, durability, and biodegradability as well as equitable design considerations are explored.

Back to the basics: The need for an etiological classification of chronic heart failure

The left ventricular (LV) ejection fraction (LVEF), despite its severe limitations, has had an epicentral role in heart failure (HF) classification, management, and risk stratification for decades. The major argument favoring the LVEF based HF classification has been that it defines groups of patients in which treatment is effective. However, this reasoning has recently collapsed, since medical treatment with neurohormonal inhibitors, has proved beneficial in most HF patients regardless of the LVEF. In addition, there has been compelling evidence, that the LVEF provides poor guidance for device treatment of chronic HF (implantation of cardioverter defibrillator, cardiac resynchronization therapy) since sudden cardiac death may occur and cardiac dyssynchronization may be disastrous in all HF patients. The same holds true for LV assist device implantation, in which the LVEF has been used as a surrogate for LV size. In this review article we update the evidence questioning the use of LVEF-based HF classification and argue that guidance of chronic HF treatment should transition to more contemporary concepts. Specifically, we propose an etiologic chronic HF classification predominantly based on epidemiological data, which will be foundational for further higher resolution phenotyping in the emerging era of precision medicine.

Advanced Heart Failure: Therapeutic Options and Challenges in the Evolving Field of Left Ventricular Assist Devices

Heart Failure is a chronic and progressively deteriorating syndrome that has reached epidemic proportions worldwide. Improved outcomes have been achieved with novel drugs and devices. However, the number of patients refractory to conventional medical therapy is growing. These advanced heart failure patients suffer from severe symptoms and frequent hospitalizations and have a dismal prognosis, with a significant socioeconomic burden in health care systems. Patients in this group may be eligible for advanced heart failure therapies, including heart transplantation and chronic mechanical circulatory support with left ventricular assist devices (LVADs). Heart transplantation remains the treatment of choice for eligible candidates, but the number of transplants worldwide has reached a plateau and is limited by the shortage of donor organs and prolonged wait times. Therefore, LVADs have emerged as an effective and durable form of therapy, and they are currently being used as a bridge to heart transplant, destination lifetime therapy, and cardiac recovery in selected patients. Although this field is evolving rapidly, LVADs are not free of complications, making appropriate patient selection and management by experienced centers imperative for successful therapy. Here, we review current LVAD technology, indications for durable MCS therapy, and strategies for timely referral to advanced heart failure centers before irreversible end-organ abnormalities.