BACKGROUND
The potential for myocardial reconditioning and device explantation after long-term continuous-flow left ventricular assist device (LVAD) support presents an opportunity to delay or avoid transplantation in select patients.
METHODS
Thirty of 657 patients with end-stage heart failure supported with continuous-flow LVADs were assessed for device explantation. Each patient underwent an individualized process of weaning focused on principles of ventricular unloading, gradual reconditioning, and transition to medical therapy.
RESULTS
After varying reconditioning periods, 27 patients (16 men, 11 women; age, 39 ± 12 years) underwent LVAD explant, and 3 patients (2 men, 1 woman; age, 22 ± 6 years) were evaluated for explantation but could not be weaned. The duration of LVAD support was 533 ± 424 days (range, 42– 1,937 days) for the explant cohort and 1,097 ± 424 days (range, 643–1,483) for the non-explant cohort. The LV end-diastolic dimension, LV ejection fraction, systolic pulmonary artery pressure, cardiac output, and cardiac index in the explant cohort were significantly improved at explantation (all, p < 0.05). Two late deaths occurred after LVAD explantation despite satisfactory native cardiac function, and 1 patient required resumption of LVAD support 2.7 years after device removal. The remaining explant patients remain in New York Heart Association classes I to II with medical management alone (mean survival post-explant, 1,172 ± 948 days). The 3 candidates who could not be weaned ultimately underwent transplantation.
CONCLUSIONS
The potential for recovery of native LV function after long-term continuous-flow LVAD support should encourage a more aggressive approach to ventricular reconditioning with the goal of device explantation and a return to medical management, particularly in young patients with dilated cardiomyopathy.
BACKGROUND
Continuous-flow left ventricular assist devices (LVADs) expose blood cells to high shear stress, potentially resulting in the production of microparticles that express phosphatidylserine (PS+) and promote coagulation and inflammation. In this prospective study, we attempted to determine whether PS+ microparticle levels correlate with clinical outcomes in LVAD-supported patients.
METHODS
We enrolled 20 patients undergoing implantation of the HeartMate II LVAD and 10 healthy controls who provided reference values for the microparticle assays. Plasma was collected before LVAD implantation, at discharge, at 3-month follow-up, and when an adverse clinical event occurred. We quantified PS+ microparticles in the plasma using flow cytometry.
RESULTS
During the study period, 8 patients developed adverse clinical events: ventricular tachycardia storm (n=1), non–ST-elevation myocardial infarction (n=2), arterial thrombosis (n=2), gastrointestinal bleeding (n=2), and stroke (n=3). Levels of PS+ microparticles were higher in patients at baseline than in healthy controls (2.11%±1.26 vs 0.69±0.46, P=0.007). After LVAD implantation, patient PS+ microparticle levels increased to 2.39%±1.22 at discharge and then leveled to 1.97%±1.25 at 3-month follow-up. Importantly, patients who developed an adverse event had significantly higher levels of PS+ microparticles than did patients with no events (3.82%±1.17 vs 1.57%±0.59, P<0.001), even though the 2 patient groups did not markedly differ in other clinical and hematologic parameters.
CONCLUSIONS
Our results suggest that an elevation of PS+ microparticle levels may be associated with adverse clinical events. Thus, measuring PS+ microparticle levels in LVAD-supported patients may help identify patients at increased risk for adverse events.
A Large Single-Center StudyLeft ventricular assist device (LVAD) C irculatory support with left ventricular assist devices (LVADs) has emerged as a powerful therapy that can improve outcomes in patients who have advanced heart failure (HF) refractory to medical therapy.1-3 The scarcity of donor organs severely limits transplantation as an option for patients with advanced HF; moreover, transplant patients need lifelong immunosuppression, the medications for which can have their own serious side effects. The newest generation of LVADs comprises continuous-flow (CF) pumps, which use axial or centrifugal technology, deliver flows of up to 10 L/min, 2,4 and are smaller and more durable than previous models. Currently, these LVADs are implanted either as a bridge to transplantation (BTT) or as destination therapy (DT), which offers a permanent alternative to transplantation.Recently, patients with end-stage HF were given new options when the U.S. Food and Drug Administration (FDA) approved 2 continuous-flow LVADs: the HeartMate ® II (Thoratec Corporation; Pleasanton, Calif ) and the HeartWare ® Ventricular Assist System (HeartWare Inc.; Framingham, Mass). The HeartMate II was approved for BTT in 2008 and for DT in 2010, and the HeartWare was approved for BTT in 2012. These milestones initiated modern LVAD therapy, enabling this treatment to become available to a larger population of patients. [5][6][7][8][9] Consequently, LVAD use has dramatically increased throughout the world, particularly for DT, and growing numbers of medical centers are offering device therapy. [9][10][11] This trend has been bolstered by reports that LVAD use, in HF patients 70 years of age or older, is associated with
In our series of contemporary CF-VAD exchanges, a history of previous cerebrovascular events was a significant predictor for exchange. Exchange did not affect early or late survival. Our data suggest that aggressive surgical treatment of pump-related complications with exchange is safe and justified.
Continuous-flow LVAD support may significantly improve hepatic function, allowing patients with poor preimplant liver function to become better candidates for heart transplantation.
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