Echocardiographic Changes in Patients Implanted With a Fully Magnetically Levitated Left Ventricular Assist Device (Heartmate 3).

BACKGROUND: The Heartmate 3 (HM3) is a Conformiteé Européenne mark-approved left ventricular (LV) assist device (LVAD) with fully magnetically levitated rotor and features consisting of a wide range operational speeds, wide flow paths, and artificial pulse. We performed a hemodynamic-echocardiographic speed optimization evaluation in HM3-implanted patients to achieve optimal LV- and right ventricular (RV) shape. METHODS AND RESULTS: Sixteen HM3 patients underwent pump speed ramp tests with right heart catheterization. Three-dimensional echocardiographic (3DE) LV and RV datasets (Philips) were acquired, and volumetric (Tomtec) and shape (custom software) analyses were performed (LV: sphericity, conicity; RV: septal and free-wall curvatures). Data were recorded at up to 13 speed settings. Speed changes were in 100-rpm steps, starting at 4600 rpm and ramping up to 6200 rpm. 3DE was feasible in 50% of the patients. Mean original speed was 5306 ± 148 rpm. LV end-diastolic (ED) diameter (-0.15 ± 0.09 cm/100 rpm) and volumes (ED: 269 ± 109 mL to 175 ± 90 mL; end-systolic [ES]: 234 ± 111 mL to 146 ± 81 mL) progressively decreased as the shape became less spherical and more conical; RV volumes initially remained stable, but at higher speeds increased (ED: from 148 ± 64 mL to 181 ± 92 mL; ES: 113 ± 63 mL to 130 ± 69 mL). On average, the RV septum became less convex (bulging toward the LV) at the highest speeds. CONCLUSIONS: LV and RV shape changes were noted in HM3-supported patients. Although a LV volumetric decrease and shape improvement was consistently noted, RV volumes grew in response to increase in speed above a certain point. A next concern would be whether understanding of morphologic and function changes in LV and RV during LVAD speed change assessed with the use of 3DE helps to optimize LVAD speed settings and improve clinical outcomes.

The evolving role of the total artificial heart in the management of end-stage congenital heart disease and adolescents.

Advances in medical therapies have yielded improvement in morbidity and a decrease in mortality for patients with congenital heart disease, both surgically palliated and uncorrected. An unintended consequence is a cohort of adolescent and adult patients with heart failure who require alternative therapies. One intriguing option is placement of a total artificial heart (TAH) either as a bridge to transplant or as a destination therapy. Of the 1091 Jarvik-7 type TAH (Symbion, CardioWest and SynCardia) placed between 1985 and 2012, only 24 have been performed in patients with congenital heart disease, and a total of 51 were placed in patients younger than 21. At our institution, the SynCardia TAH was implanted in a 19-year-old patient with cardiac allograft failure because of chronic rejection and related multisystem organ failure including need for hemodialysis. Over the next year, she was nutritionally and physically rehabilitated, as were her end organs, allowing her to come off dialysis, achieve normal renal function and eventually be successfully transplanted. Given the continued growth of adolescent and adult congenital heart disease populations with end-stage heart failure, the TAH may offer therapeutic options where previously there were few. In addition, smaller devices such as the SynCardia 50/50 will open the door for applications in smaller children. The Freedom Driver offers the chance for patients to leave the hospital with a TAH, as does the AbioCor, which is a fully implantable TAH option. In this report, we review the history of the TAH and potential applications in adolescent patients and congenital heart disease.

The future of heart transplantation.

The field of heart transplantation has seen significant progress in the past 40 years. However, the breakthroughs in long-term outcome have seen stagnation in the past decade. Through advances in genomics and transcriptomics, there is hope that an era of personalized transplant therapy lies in the future. To see where heart transplantation truly fits into the long term, searching for and understanding the alternative approaches for heart failure therapy is both important and inevitable. The application of mechanical circulatory support has contributed to the largest advancement in treatment of end stage heart failure. It has already been approved for destination therapy of heart failure, and greater portability and ease of use of the device will be the future trend. Although it is still not prime time for stem cell therapy, clinical experiences have already suggested its potential therapeutic effects. And finally, whole organ engineering is on the horizon as new techniques have opened the way for this to proceed. In the end, progress on alternative therapies largely depends on our deeper understanding of the mechanisms of heart failure and how to prevent it.

Bridge to recovery: what remains to be discovered?

The use of left ventricular assist devices to induce substantial myocardial recovery with explantation of the device, bridge to recovery (BTR), is an exciting but currently grossly underused application. Recently acquired knowledge relating to BTR and its mechanisms offers unprecedented opportunities to streamline its use and unravel some of the secrets of heart failure with much wider implications. This article reviews the status, challenges, and future of cardiac recovery.