Left Lateral Thoracotomy for Centrifugal Continuous-Flow Left Ventricular Assist Device Placement: An Analysis from the Mechanical Circulatory Support Research Network
Continuous-flow left ventricular assist devices (CF-LVADs) have revolutionized the management of patients with advanced heart failure. Alternative implant strategies are increasingly used for device placement. We reviewed our experience from the Mechanical Circulatory Support Research Network registry with the HeartWare centrifugal CF-LVAD (HVAD). From May 2004 to August 2015, 1,150 patients underwent primary CF-LVAD implantation at our institutions. Within this group, a total of 283 patients (25%) were implanted with the HVAD. A minimally invasive left lateral thoracotomy (MILT) implant strategy was used in 53 patients (20%), of which 22 (42%) were implanted off-pump. Median age at implant was 59 years and 183 patients (65%) were implanted as bridge-to-transplantation. Follow-up was 100% complete for a total of 302 patient-years of support. In-hospital mortality was 4.9% (14 patients), and was comparable between the conventional sternotomy (CS) and MILT cohorts (p = 0.15). Patients in the MILT cohort had a shorter median length of stay (p < 0.01) and had a lower incidence of postimplant pump thrombus (p = 0.02). Cumulative survival at the end of follow-up reached 84%, and was comparable between the two groups (p = 0.298). Multivariate analysis identified preoperative bilirubin level as the only independent predictor of survival. Surgical technique had no impact on survival. In this large, multicenter experience, data demonstrate excellent survival and adverse event profiles for patients supported with the HVAD technology, regardless of surgical implant technique. With constant advancements in device technology along with our increasing clinical experience with the newer techniques, minimally invasive LVAD implantation continues to evolve as a valuable alternative to CS in selected patients.
Single Versus Multidrug Regimen for Surgical Infection Prophylaxis in Left Ventricular Assist Device Implantation
Infection is a serious complication of left ventricular assist device (LVAD) therapy. However, an optimal antimicrobial surgical infection prophylaxis (SIP) regimen for LVAD implantation is not well established. We retrospectively reviewed all adults who underwent continuous-flow LVAD implantation from February 2007 to March 2015 at Mayo Clinic Rochester. Left ventricular assist device infection (LVADI) was defined using criteria published by the International Society for Heart and Lung Transplant. Patients excluded from the analysis included those who did not have HeartMate II or HeartWare device, patients with incomplete documentation of SIP, and those with an actively treated infection at the time of LVAD implantation. We compared risk of LVAD-specific and LVAD-related infections and all-cause mortality between SIP regimens at postoperative day 90 and 1 year using Kaplan–Meier time-to-event analyses. During study period, 239 adults underwent continuous-flow LVAD implantation at our institution where 199 patients received single-drug and 40 received multidrug SIP regimen. Median patient age was 62 years. Left ventricular assist device infection occurred in three patients (1.5%) in the single-drug group versus two patients (5.0%) in the multidrug group at 90 days (p = 0.4). There was no difference in infection-free (p = 0.4) and overall survival (p = 0.9) between two groups at 1 year. In conclusion, there was no clear benefit of using multidrug regimen as it did not impact infection-free survival or all-cause mortality compared with single-drug regimen. Prospective clinical trials are needed to further define the optimal SIP regimen for LVAD implantation.
Pulmonary arteriovenous extracorporeal membrane oxygenation to avoid pulmonary overflow during total artificial heart implantation
Total artificial hearts (TAH) can be used as a bridge to transplant or, occasionally, as destination therapy for patients with severe biventricular dysfunction. Not infrequently TAHs are placed in patients with severe low flow states, in which the lungs of these patients are unable to adjust rapidly to the “normal” right ventricular output of a TAH. These patients may develop variable degrees of pulmonary edema secondary to stress failure of the pulmonary capillaries requiring increased respiratory support, which can occasionally be fatal. In this “how to do it” article, we describe the technique for a pulmonary arteriovenous extracorporeal membrane oxygenation with TAH to avoid sudden pulmonary overflow and gradually expose the lungs to increasing flow.
Atrial Fibrillation Should Guide Prophylactic Tricuspid Procedures During Left Ventricular Assist Device Implantation
Atrial fibrillation (AF) and tricuspid regurgitation (TR) are common in patients undergoing left ventricular assist device (LVAD) implantation. TR progression is associated with the presence of AF, and questions remain as to who benefits from tricuspid valve procedures (TVPs). We examined the impact of preoperative AF on TR progression after LVAD implantation. From February 2007 to May 2014, 250 patients underwent LVAD implantation at our institution. Patients with concomitant TVP were excluded from this analysis (113 patients). The indication for LVAD was destination therapy in 80 patients (58%) and the etiology of heart failure was ischemic in 73 (53%). Follow-up was available in all early survivors for a total of 393 patient-years of support. Of the 137 non-TVP patients, 52 (38%) had AF preoperatively. Observed overall survival at 1, 3, and 5 years was 82%, 67%, and 55%, respectively. Median grade of TR increased from 2 preoperatively to 3 (p = 0.04) in the AF group and 2.2 (p = 0.75) in the non-AF group at 5 years of follow-up. We also observed a significant difference in the degree of TR between groups at 3 months (p = 0.03) and 12 months (p = 0.01) postimplantation, and a trend toward significance at 18 (p = 0.06) and 24 (p = 0.07) months. The presence of AF is associated with early progression of TR after LVAD implantation. Addition of concomitant TVP in patients with preoperative AF may be considered in patients with less than severe TR. The impact of these findings on right ventricular failure/remodeling remains to be evaluated.
Update in Artificial Heart Technology: Are We There Yet?
Percutaneous Transcatheter Interventions for Aortic Insufficiency in Continuous-Flow Left Ventricular Assist Device Patients: A Systematic Review and Meta-Analysis
De novo progressive aortic insufficiency (AI) is a side effect frequently related to prolonged support with continuous-flow left ventricular assist devices (CF-LVAD). Its progression can result in recurrent clinical heart failure symptoms and significantly increased mortality. Recently, percutaneous intervention methods, such as transcatheter aortic valve replacement (TAVR) and percutaneous occluder devices, have emerged. However, given the very scarce global experience with these approaches, evidence in the literature is lacking. We sought to assess the outcomes of CF-LVAD patients who had undergone percutaneous intervention for AI. A systematic search of six databases from inception to April 2016 was performed by two independent reviewers. Eligible studies were those that included series or cases where patients had percutaneous transcatheter interventions for AI in CF-LVAD patients. Data were extracted and meta-analyzed from the identified studies. A total of 29 patients from 15 published studies and 3 unpublished records were included in the analysis. Mean patient age was 56.6 ± 13.7 years, and 72.4% were male. The etiology of heart failure resulting in LVAD placement was ischemic cardiomyopathy in 17.2%. The two intervention groups were TAVR (27.6%) and occluder devices (72.4%). A transfemoral approach (69%), apical approach (10%), brachial approach (7%), subclavian approach (3%), and mini-sternotomy (3%) were used. The preintervention AI grade was severe with a median grade of 4 (interquartile range, 4–4). Postoperatively, the AI grade improved significantly to a median grade of 0 (0–2). At long-term follow-up AI grade was still trivial with a median AI grade of 1 (0–1). Subgrouping the treatments into the occluder device and TAVR, it was found that both interventional techniques were similarly effective in reducing the AI grade from severe to trivial. In terms of complications, from the occluder group, two patients were complicated with device migration and another two with transient hemolysis. In the TAVR cohort, two patients experienced device migration and another had significant postimplant perivalvular leakage. Our results indicate that percutaneous interventions for AI in CF-LVAD patients with TAVR, and closure devices demonstrate similar efficacy in significantly reducing severe AI. Current results are encouraging, potentiating viability as a treatment option, particularly in nonsurgical candidates. Future research with larger patient cohorts and comparative controls is required to sufficiently evaluate the efficacy of this technique and promote its widespread acceptance as a mainstay treatment.