Invasive Left Ventricular Assist Device Research Articles

Abstract 13623: In Silico Comparison of Pressure Head Loss for Outflow Variations of a Novel LVAD Accessory Compared to Generic LVAD Pump Outflow

Introduction: Left ventricular assist device (LVAD) implantation is a treatment option for end-stage heart failure, requiring a sternotomy. A novel accessory, redirecting the outflow via the left ventricular apex into the ascending aorta, allows for LVAD implantation via left thoracotomy. Pressure distribution within accessory designs is unknown. Our goal was to compare three different outflow designs with a generic LVAD outflow (Control) to optimize the accessory’s outflow design. Hypothesis: We hypothesize that the LVAD accessory leads to higher pressure head loss than Control and that there are relevant differences among varied designs. Methods: Volume models of the LVAD accessory variations (A–C) and Control were created using computer aided design. Computational fluid dynamics (CFD) was used to simulate blood flow through the accessories and generic outflows. A verification study was performed to optimize numerical parameters. Pressure head loss (mmHg) was calculated for each outflow while changing the LVAD flow rate continuously (2–7 L/min). Pressure loss was compared by mean differences (MD). Results: Pressure head loss increased with higher LVAD flow rate among all groups. Addressing the accessories’ outflow designs, Design B revealed the lowest increase in pressure loss revealing a mean slope of 2.3 mmHg/L/min compared to 4.6 and 3.0 for Design A and C. Referring to a flow rate of 5.5 L/min, a common flow rate among clinical LVAD patients, and comparing pressure head loss with Control, we found an additional pressure loss of 15.5, 6.4 and 8.3 mmHg in Design A, B and C, respectively. Conclusion: There is a trade off between fitting the outflow design to the cardiac geometry and the pressure head loss. Continued optimization of the LVAD accessory could allow minimally invasive LVAD implantation with minimal changes in LVAD performance. Potential compromise between improved design and performance renders CFD an important tool for medical device development.

Right Ventricular Contractility and Pulmonary Arterial Coupling After Less Invasive Left Ventricular Assist Device Implantation.

Right ventricular failure contributes significantly to morbidity and mortality after left ventricular assist device implantation. Recent data suggest a less invasive strategy (LIS) via thoracotomy may be associated with less right ventricular failure than conventional median sternotomy (CMS). However, the impact of these approaches on load-independent right ventricular (RV) contractility and RV-pulmonary arterial (RV-PA) coupling remains uncertain. We hypothesized that the LIS approach would be associated with preserved RV contractility and improved RV-PA coupling compared with CMS. We performed a retrospective study of patients who underwent durable, centrifugal left ventricular assist device implantation and had paired hemodynamic assessments before and after implantation. RV contractility (end-systolic elastance [Ees]), RV afterload (pulmonary effective arterial elastance [Ea]), and RV-PA coupling (Ees/Ea) were determined using digitized RV pressure waveforms. Forty-two CMS and 21 LIS patients were identified. Preimplant measures of Ees, Ea, and Ees/Ea were similar between groups. After implantation, Ees declined significantly in the CMS group (0.60-0.40, p = 0.008) but not in the LIS group (0.67-0.58, p = 0.28). Coupling (Ees/Ea) was unchanged in CMS group (0.54-0.59, p = 0.80) but improved significantly in the LIS group (0.58-0.71, p = 0.008). LIS implantation techniques may better preserve RV contractility and improve RV-PA coupling compared with CMS.

Less Invasive Left Ventricular Assist Device Implantation Is Safe and Feasible in Patients With Smaller Body Surface Area.

Smaller body surface area (BSA) frequently precludes patients from left ventricular assist device (LVAD) therapy. We sought to investigate the clinical outcomes in patients with small BSA undergoing less invasive LVAD implantation. We conducted a retrospective review of 216 patients implanted with HeartMate 3 LVAD (Abbott, Chicago, IL) via less invasive surgery at our institution. Patients were dichotomized based on their preimplant BSA for comparison between small BSA (≤1.8 m2) and normal/large BSA (>1.8 m2). We analyzed patient perioperative characteristics and outcomes. In our study, small BSA was found in 32 patients (14.8%), while 184 patients (85.2%) had normal/large BSA. Women were more prevalent in the small BSA group (50.0% vs 13.0%, P < 0.001). Preoperative and intraoperative data showed comparable results. Major complications and hospital length of stay did not differ by BSA group. Patients with smaller BSA had significantly decreased pump parameters at discharge, including LVAD flow (4.11 ± 0.49 vs 4.60 ± 0.54 L/min, P < 0.001) and pump speed (5,200 vs 5,400 rpm, P < 0.001). Survival to discharge and within 6 months after implantation were similar between the groups. Our study results suggest that less invasive HeartMate 3 implantation can be safely performed and demonstrates equivalent outcomes in patients with smaller body habitus. Randomized trials are required to confirm our data.

Left atrial appendage exclusion with less invasive left ventricular assist device implantation.

The objective of this single-center, pilot, prospective, and historical control study is to evaluate safety and feasibility outcomes associated with left atrial appendage exclusion (LAAE) concomitant with left ventricular assist device (LVAD) implantation via less invasive surgery (LIS) as a stroke prevention strategy. A predefined number of 30 eligible subjects scheduled for LIS LVAD with LAAE were enrolled in the prospective arm between January 2020 and February 2021. Eligible retrospective LIS LVAD patients without LAAE were propensity-matched in a 1:1 ratio with the prospective arm subjects. The primary study objectives were to evaluate the safety, feasibility, and efficacy of the LAAE concomitant with LIS LVAD. Preoperative characteristics of patients in the Non-LAAE and LAAE groups were similar. LAAE was successfully excluded in all prospective patients (100%). Primary safety endpoints of chest tube output within the first 24 postoperative hours, Reoperation for bleeding within 48 h, and index hospitalization mortality demonstrated comparable safety of LAAE versus Non-LAAE with LIS LVAD. Cox proportional hazard regression demonstrated that LAAE with LIS LVAD was associated with 37% and 49% reduction in the risk of stroke and disabling stroke, respectively (p > .05). Results from our pilot study demonstrated the safety and feasibility of LAAE concomitant with LIS LVAD as a stroke prevention strategy. This is the first prospective study describing LAAE performed concomitantly to less invasive LVAD implantation. The efficacy of LAAE in long-term stroke prevention needs to be confirmed in future prospective randomized clinical trials.

Minimally Invasive Left Ventricular Assist Device Insertion with Concomitant Aortic Valve Replacement Despite Prior Sternotomy

<h3>Introduction</h3> Minimally-invasive approaches to left ventricular assist device (LVAD) insertion have been described. However, reoperative sternotomy and/or need for concomitant procedures have been regarded as relative contraindications to a minimally-invasive approach. <h3>Case Report</h3> A 61 year-old female with ischemic cardiomyopathy and prior coronary bypass grafting via median sternotomy was deemed an appropriate candidate for LVAD insertion. While preoperative echocardiography demonstrated mild aortic insufficiency, intra-operative imaging revealed moderate aortic insufficiency. Intra-operatively, the aorta was accessed via a partial upper sternotomy to the 4^th intercostal space. The ventricular apex was accessed through a left anterolateral thoracotomy. Cardiopulmonary bypass was established via an aortic cannula inserted via the ascending aorta and a multi-stage venous cannula inserted into the right femoral vein. Cardioplegia was administered first via an antegrade aortic root catheter, and then later via retrograde catheter and direct coronary ostial cannulation during the valve replacement. The aortic valve was replaced with a 21-mm bioprosthetic valve via the partial sternotomy (Fig A). After aortotomy closure, the cross-clamp was removed and the heart re-perfused. An apical ventriculotomy was then created and the LVAD inflow cannula was inserted into the left ventricle and secured to the sewing ring (Fig B). The outflow graft was tunneled to the upper sternotomy and anastomosed to the aorta using a side-biting clamp. The postoperative course was notable for pneumonia leading to temporary re-intubation. She otherwise did well, and was discharged home on post-LVAD day 23. <h3>Summary</h3> Both a history of a prior sternotomy and the need for concomitant procedures present challenges to use of minimally-invasive approaches for LVAD insertion. Here, we demonstrate that concomitant AVR can be safely performed along with LVAD insertion in a reoperative setting.

Less Invasive Left Ventricular Assist Device Implantation is Safe and Feasible in Patients with Smaller Body Surface Area

<h3>Purpose</h3> Smaller body surface area (BSA) frequently precludes patients for Left Ventricular Assist Device (LVAD) therapy. We sought to investigate the clinical outcomes in patients with small BSA undergoing less invasive LVAD implantation. <h3>Methods</h3> We conducted a retrospective review of 216 patients implanted with HeartMate 3 LVAD via less invasive surgery (LIS) at our institution. Patients were dichotomized and compared based on their pre-implant BSA: small BSA (BSA≤1.8 m²) and normal/large BSA (BSA>1.8 m²). We analyzed patients' perioperative characteristics and outcomes. <h3>Results</h3> In our study, small BSA was found in 32 (14.8%) patients, while 184 (85.2%) had normal/large BSA (Table 1). Women were more prevalent in the small BSA group (50.0% vs. 13.0%, p<0.001). Preoperative and intraoperative data showed comparable results. Major complications and hospital length of stay did not differ by BSA group. Patients with smaller BSAs had significantly decreased pump parameters at discharge, this includes LVAD flow (4.11±0.49 vs.4.60±0.54, L/min, p<0.001) and pump speed (5200 vs. 5400, rpm, p<0.001). Survival to discharge and within 6 post-implantation months were similar between the groups (Figure 1). <h3>Conclusion</h3> Our study results suggest that less invasive HeartMate 3 implantation can be safely performed and demonstrates equivalent outcomes in patients with smaller body habitus. Randomized trials are required to confirm our data.

Study results suggest less invasive HeartMate 3 implantation is a safe and effective approach for obese patients

Historically, obesity was considered a relative contraindication to left ventricular assist device (LVAD) implantation with less invasive surgery (LIS). The present study aimed to compare the outcomes of obese patients who underwent LVAD implantation through LIS with those who received full sternotomy (FS) implantation. We retrospectively reviewed all patients implanted with HeartMate 3 LVAD in our institution between September 2015 and June 2020. Obese patients (BMI ≥ 30 kg/m2) were included and dichotomized based on surgical approach into the FS or LIS cohort. Of 231 implanted patients, 107 (46%) were obese and included in the study. FS was performed in 26 (24%) patients and LIS approach in 81 (76%) patients. Preoperative patient characteristics were similar between the cohorts. Postoperatively, patients in LIS cohort had less bleeding (p=0.029), fewer transfusions (p=0.042), shorter duration of inotropic support (p=0.049), and decreased incidence of severe RV failure (11.1% vs 30.8%, p=0.028). Survival to discharge for the obese population was 87.5% overall and did not differ based on an approach (91.4% LIS vs 76.9% FS, p=0.079). More LIS patients were discharged home (60.0% vs 82.4%, p=0.041) rather than to rehabilitation center. Our results showed that the LIS approach in obese patients is associated with fewer postoperative complications and a trend towards better short-term survival. These results suggest that less invasive LVAD implantation is a safe and effective approach for obese patients. Future prospective randomized trials are required to substantiate these results.

Minimally Invasive Left Ventricular Assist Device Implantation: A Systematic Review and Meta-Analysis

Purpose Minimally invasive (MI) approaches for left ventricular assist device (LVAD) implantation has the potential to offer similar benefits to of other well-established cardiac surgery procedures. We performed a systematic review and meta-analysis to determine the potential benefits of MI LVAD implantation compared to sternotomy. Methods We searched MEDLINE and EMBASE databases for studies comparing MI continuous-flow LVAD implantation with sternotomy. Data was extracted by two independent investigators. The main outcomes were perioperative mortality and complications. Results 19 observational studies (1619 patients) with mean follow-up of 9 months were included. HeartWare was the most commonly implanted device (80%), followed by HeartMate II (6%). Serum bilirubin was lower (MD: -5.4 uM; 95%CI: ‒8.1 to -2.7; p Conclusion MI LVAD implantation led to an improved perioperative complication profile and enhanced patient recovery, potentially decreasing mid-term mortality. These are consistent with findings from other well-established MI cardiac surgical procedures. A future randomized trial could further clarify these benefits and establish this technique as a standard practice.

Off-Pump Implant Strategy for the Jarvik 2000 LVAD

Purpose Median sternotomy and cardiopulmonary bypass (CPB) represent the gold standard for the left ventricular assist device (LVAD) implantation. Long-term survival rates in LVAD patients are highly dependent on the immediate peri- and post-operative course. The CPB deleterious effects in this fragile population include right ventricular dysfunction, bleeding, and end-organ injury. Minimally invasive strategies, with off-pump implantation and alternative access rather than sternotomy, have been recently reported for contemporary continuous-flow LVAD placement.We sought to assess the safety, feasibility, and short-term outcomes of minimally invasive off-pump LVAD implantation. Methods We retrospectively reviewed data of 19 patients who underwent off-pump Jarvik 2000 LVAD implantation, as destination therapy, from December 2010 to April 2019, at our center. The surgical access was: J-ministernotomy + left minithoracotomy in 89.5%, and anterolateral thoracotomy in 10.5% of the patients. Study endpoints were perioperative outcomes and long-term survival. Results Mean age was 67.1±5.2 years, 89.5 % were male and the underlying disease was ischemic cardiomyopathy in 42.1%. INTERMACS class was: II: 10.5%, III: 31.6%, IV: 57.9%. There were no on-pump conversions; a major bleeding required a surgical access conversion in 2 cases. Mean mechanical ventilation time was 17±7 hours, median of blood transfusion units was 6 (interquartile range 3-15). Perioperative stroke, bleeding requiring surgical re-entry and severe right ventricular failure were 5.2%, 21.1%, and zero, respectively. Median postoperative hospital stay was 30 days (interquartile range 21.5-45) with a 5.2% 30-day mortality rate. Mean duration of support was 1034.7 days (range 8-1981 days). Three patients had LVAD-related complications leading to device explant, after a mean time of 983±310 days: two patients underwent a re-do LVAD exchange, one was successfully transplanted. One- and 2-year overall survival were 77.8% ± 9.8% and 70% ± 11.5%, respectively. Conclusion Our preliminary experience shows that off-pump Jarvik 2000 LVAD implantation is feasible and safe alternative to the standard implantation technique. Good peri-operative outcomes and long-term survival rates could encourage an extended use of this strategy. However, additional implants and comparison of outcomes in larger populations are needed.

Less Invasive LVAD Implantation Decreases Postoperative Right Ventricular Dysfunction

<h3>Purpose</h3> Right ventricular failure (RVF) remains one of the major cause of morbidity and mortality after left ventricular assist device (LVAD) surgery. The purpose of this study was to investigate the incidence of RVF after less invasive surgery (LIS) LVAD surgery compared to median sternotomy. <h3>Methods</h3> The study population comprised of 231 patients who underwent HeartMate 3 LVAD implantation in our institution between September 2015 and June 2020. Patients were compared based on surgical approach: full sternotomy (FS) or LIS. The primary outcome was RVF as defined by INTERMACS. Index hospitalization major complications and survival were secondary outcomes. <h3>Results</h3> LIS approach was used in 161 (69.7%) patients and FS approach in 70 (30.3%) of our LVAD patients. Baseline patient characteristics were similar between cohorts apart from LIS patients being younger (54±14 vs 60±11, p=0.003). Postoperatively, LIS patients had decreased postoperative bleeding (p=0.001) and shorter time on mechanical ventilation (p<0.001) or inotropes (p=0.0042). LIS was associated with a 3-fold reduction in the primary endpoint of RVF (8.7% vs 28.6%; respectively; p<0.001) as well as in the need for Right Ventricular Assist Device support (5 vs 17.1%, p=0.003). Multivariate analysis showed that LIS was associated with a significant reduction in the risk of major postoperative events (Figure 1), including a 76% (p<0.001) reduction in RVF occurrence and a 75% (p=0.004) reduction in the need for RVAD support. Survival at index hospitalization was higher with LIS vs. FS (91.3% vs 78.6%, p=0.0073). <h3>Conclusion</h3> Less invasive LVAD implantation is associated with improved perioperative outcomes compared to median sternotomy, including a lower incidence of severe right heart failure and need for temporary mechanical circulatory support. Further research is needed to elucidate the mechanism of the less invasive approach in preserving RV function.

Evaluation of Thoracotomy versus Median Sternotomy Approach in Third-Generation Left Ventricular Assist Device Implantation

<h3>Purpose</h3> The purpose of this study is to compare short term results of patients undergoing a third generation (HVAD™or HeartMate™ 3) Left Ventricular Assist Device (LVAD) implantation through either minimally-invasive, thoracotomy approach or standard median sternotomy. <h3>Methods</h3> We prospectively collected data on all patients at our institution that received an LVAD from September 2008 to February 2020. Surgical approach was decided by the implanting surgeon. We used 1:1 propensity score (PS) matching to compare the sternotomy versus thoracotomy groups. A logistic regression model based on 19 explanatory variables was used to estimate the propensity score. Overall survival post-implantation was summarized using Kaplan-Meier curves and compared using the log-rank test. <h3>Results</h3> A total of 272 patients were included, of whom 194 had sternotomy and 78 had either left thoracotomy and hemi-sternotomy or bilateral thoracotomies. Using PS matching, 128 (64/64) patients were selected. Demographics and operative characteristics were well balanced between groups. Overall, there was a trend towards better survival in thoracotomy group (33.1% vs 66.4%, p=0.06) at 5 years, but higher stroke rate (11% in sternotomy group vs 21% in thoracotomy group, p = 0.035). Following PS-matching, however, there was no difference in early or late mortality (Graph 1) but there was a higher rate of pump exchange in the thoracotomy group (2% vs 9%, p = 0.052). There was no difference in perioperative stroke rates (sternotomy 6% vs thoracotomy 9%), extubation time (2.5 days vs 2.5 days), right ventricular failure (13% vs 14%), renal failure (8% vs 5%) or hospital readmissions (81% vs 88%). <h3>Conclusion</h3> Minimally invasive LVAD implantation is feasible and safe in the current LVAD era. In a PS matched analysis, patients in the minimally invasive group displayed lower overall mortality, but without reaching statistical significance. Adverse events were similar in both groups.

Impact of Less Invasive Left Ventricular Assist Device Implantation on Heart Transplant Outcomes

Left ventricular assist device implantation without sternotomy (LIS) may simplify heart transplantation (HTX) by avoiding adhesions and eliminating the need for a re-sternotomy. This study investigates the impact of LIS LVAD implantation on HTX outcomes. A retrospective comparison of 46 patients undergoing HTX between 07/13 and 06/19 after conventional LVAD implantation with a full sternotomy (FS) and LIS LVAD implantation (LIS: n = 27 patients, 59%; FS: n = 19 patients, 41%) was performed. Endpoints were perioperative data including blood product use, de-novo formation of donor specific antibodies (DSAs) and survival. Patient demographics (mean age FS: 60.3 ± 9.3 years vs LIS 58.0 ± 7.7 years, P = 0.313; male gender FS: 84% vs LIS: 82%, P = 1.000; urgent HTX FS: 16% vs LIS 18%, P = 1.000) were comparable between LIS and FS patients. The primary finding was a significantly higher risk to develop de novo donor specific antibodies (DSAs) after HTX in patients of the FS group (FS: 36% vs LIS: 4%; P = 0.006). LIS patients had a significant reduction of intraoperative packed red blood cells (PRBCs) use (LIS: 4 (IQR 2-7) Units vs FS: 7 (IQR 4-8) Units; P = 0.045). Other adverse events rates and in-hospital mortality (LIS: 7% vs FS 5%, P = 1.000) were comparable between both groups. LIS LVAD reduces formation of donor specific antibodies after HTX.

Minimally Invasive Left Ventricular Assist Device Insertion Facilitates Subsequent Heart Transplant.

We have observed that minimally invasive left ventricular assist device (LVAD) insertion leads to more facile re-entry and easier cardiac transplantation. We hypothesize minimally invasive LVAD implantation results in improved outcomes at the time of subsequent heart transplant. All adults undergoing cardiac transplantation between October 2015 and March 2019 at our institution were retrospectively reviewed. Those bridged to transplantation with a HeartWare HVAD were identified and divided into 2 cohorts based upon the surgical approach: those who underwent HVAD placement by conventional sternotomy versus minimally invasive insertion via lateral thoracotomy and hemisternotomy (LTHS). Patient demographics, as well as perioperative transplant outcomes, including survival, length of stay (LOS), blood utilization, ischemic time, bypass time, and postoperative extracorporeal membrane oxygenation (ECMO) were compared between cohorts. Forty-two patients were bridged to heart transplant with a HVAD implanted via either sternotomy (n = 22) or LTHS technique (n = 20). Demographics were similar between groups. There was 1 predischarge death in the sternotomy group and none in the LTHS group. Body surface area, cardiopulmonary bypass time, ischemic time, ECMO utilization, and reoperation for bleeding were similar. Red blood cell units transfused were significantly lower in the LTHS cohort (3.0 [1.0-5.0] vs 6.0 [2.5-10.0] P = 0.046). The LTHS cohort had a significantly shorter hospital LOS (12.0 [11.0-28.0] vs 22.5 [15.7-41.7] P = 0.022) with a trend toward shorter intensive care unit LOS (6.0 [5.0-10.5] vs 11.0 [6.0-21.5] days P = 0.057). Minimally invasive HVAD implantation improves outcomes at subsequent heart transplantation, resulting in shorter LOS and less red cell transfusion. Larger multi-institutional studies are necessary to validate these findings.

The Partial Support of the Left Ventricular Assist Device Shifts the Systemic Cardiac Output Curve Upward in Proportion to the Effective Left Ventricular Ejection Fraction in Pressure-Volume Loop.

Left ventricular assist device (LVAD) has been saving many lives in patients with severe left ventricular (LV) failure. Recently, a minimally invasive transvascular LVAD such as Impella enables us to support unstable hemodynamics in severely ill patients. Although LVAD support increases total LV cardiac output (COTLV) at the expense of decreases in the native LV cardiac output (CONLV), the underlying mechanism determining COTLV remains unestablished. This study aims to clarify the mechanism and develop a framework to predict COTLV under known LVAD flow (COLVAD). We previously developed a generalized framework of circulatory equilibrium that consists of the integrated CO curve and the VR surface as common functions of right atrial pressure (PRA) and left atrial pressure (PLA). The intersection between the integrated CO curve and the VR surface defines circulatory equilibrium. Incorporating LVAD into this framework indicated that LVAD increases afterload, which in turn decreases CONLV. The total LV cardiac output (COTLV) under LVAD support becomes COTLV = CONLV+EFe · COLVAD, where EFe is effective ejection fraction, i.e., Ees/(Ees+Ea). Ees and Ea represent LV end-systolic elastance (Ees) and effective arterial elastance (Ea), respectively. In other words, LVAD shifts the total LV cardiac output curve upward by EFe · COLVAD. In contrast, LVAD does not change the VR surface or the right ventricular CO curve. In six anesthetized dogs, we created LV failure by the coronary ligation of the left anterior descending artery and inserted LVAD by withdrawing blood from LV and pumping out to the femoral artery. We determined the parameters of the CO curve with a volume-change technique. We then changed the COLVAD stepwise from 0 to 70–100 ml/kg/min and predicted hemodynamics by using the proposed circulatory equilibrium. Predicted COTLV, PRA, and PLA for each step correlated well with those measured (SEE; 2.8 ml/kg/min 0.17 mmHg, and 0.65 mmHg, respectively, r2; 0.993, 0.993, and 0.965, respectively). The proposed framework quantitatively predicted the upward-shift of the total CO curve resulting from the synergistic effect of LV systolic function and LVAD support. The proposed framework can contribute to the safe management of patients with LVAD.

Less Invasive Reoperative Ventricular Assist Device Insertion for Patients With Patent Bypass Grafts

We report our technique for left ventricular assist device insertion that is useful in patients with patent coronary artery bypass grafts or mediastinal adhesions from other previous surgeries. An inverted-T upper hemisternotomy is made at the level of the second or third intercostal space, and with the left sternal section retracted, dissection is carried along the chest wall into the left pleural space. The device is implanted in the left ventricular apex via a left thoracotomy in the fifth or sixth intercostal space. The outflow graft is routed through the left pleural space and anastomosed to the ascending aorta.

Less Invasive Left Ventricular Assist Device Implantation Is Safe and Reduces Intraoperative Blood Product Use: A Propensity Score Analysis VAD Implantation Techniques and Blood Product Use.

Despite increasing popularity and multiple postulated benefits, less invasive (LIS) left ventricular assist device (LVAD) implantation has not been sufficiently compared with standard full sternotomy (FS). We report the outcomes of a propensity score analysis designed to compare LIS and FS LVAD implantation, with perioperative blood product use, adverse event rates, and mortality as primary objective. From September 2010 to August 2016, 159 consecutive patients received a Medtronic HVAD or Abbott HeartMate 3 LVAD via a FS or LIS approach. Outcomes were analyzed using proportional hazard Cox regression, with risk adjustment based on a LIS approach propensity score model computed from demographics, risk factors, and operative covariates. Seventy-five patients were matched and compared (HVAD 83% [n = 62]; LIS approach 43% [n = 32]; mean age 60 ± 12 years; 89% [n = 67] male; 48% [n = 36] ischemic cardiomyopathy [ICMP]; 37% [n = 28]). Patient groups were comparable with regard to preoperative patient characteristics. Less invasive LVAD implantation was successful in all patients with no intraoperative conversions. In-hospital mortality was 16% in both groups, despite 37% Interagency Registry for Mechanically Assisted Circulatory Support Level I patients. Overall, 28% of the LIS patients did not receive any blood products intraoperatively, whereas, in the FS group, only two patients (5%) did not require the administration of blood products (p = 0.000). This was also a significant finding in the overall perioperative phase in which seven LIS patients (22%) who not receive any blood products versus two FS patients (5%; p = 0.033). Otherwise, outcomes were comparable. Less invasive LVAD implantation is a feasible, safe, and reduces blood product use.

Less Invasive Approach to Left Ventricular Assist Device Implantation May Improve Survival in High-Risk Patients

Despite improvement in outcomes after left ventricular assist device (LVAD) implantation over the past 2 decades, high-risk recipients continue to have a prohibitive rate of morbidity and mortality. We hypothesized that a less invasive approach to LVAD implantation would be associated with improved survival compared to a conventional approach in this high-risk cohort. All consecutive LVAD recipients (2013 to 2017) that underwent centrifugal LVAD implantation were retrospectively reviewed. Patients were classified as high-risk if INTERMACS 1 or required temporary VAD/venoarterial extracorporeal membrane oxygenation prior to durable VAD implantation. Patients were stratified into 3 groups: left thoracotomy with hemi-sternotomy (LTHS) high-risk, conventional sternotomy (CS) high-risk, and non-high-risk. The primary outcome was 1-year survival. A total of 57 patients (LTHS high-risk: 11, CS high-risk: 12, non-high-risk: 34) were identified. Preoperative right ventricular failure scores, HeartMate-II mortality scores, and end-organ dysfunction were similar between the 2 high-risk groups. While operative time was similar between the 3 groups, cardiopulmonary bypass time was significantly shorter in the LTHS high-risk group compared to other groups. There was a trend toward decreased intensive care unit length of stay and ventilator time in LTHS high-risk compared to CS high-risk patients. Moreover, between these 2 groups, there was a significant decrease in temporary right VAD support (50% vs 0%, P = 0.014), and 1-year survival was significantly higher in the LTHS group (42% vs 91%, P = 0.025). Less invasive LVAD implantation appears to be associated with improved survival compared to conventional LVAD implantation in high-risk patients.

Concurrent Left Atrial Appendage Occlusion and Sternal-Sparing LVAD Implantation

Thromboembolic events (TEs) remain common adverse events for left ventricular assist device (LVAD) patients. There is early evidence that left atrial appendage occlusion (LAAO) at the time of LVAD implantation may reduce the incidence of TEs, but the feasibility of LAAO during less invasive LVAD implantation is unknown. Patients who underwent LAAO during LVAD implantation via the complete sternal-sparing (CSS) approach were retrospectively reviewed. LAAO was performed through the left thoracotomy incision using a commercially available left atrial appendage exclusive device. Preoperative patient characteristics, intraoperative data, and postoperative complications were collected. The primary outcome was incidence of intraoperative complications. Secondary outcomes included operative time, successful placement of exclusion device, and incidence of postoperative TEs. A total of 8 patients underwent concurrent LAAO at the time of CSS LVAD implantation. Average age was 62 ±12 years and five (63%) patients were male. Two patients (25%) were INTERMACS Profile 1, five (63%) Profile 3, and one (12%) was Profile 4. Four patients (50%) had evidence of preoperative left ventricular thrombus, and six (75%) had a history of arrhythmia. All patients received a fully magnetically levitated LVAD. There were no intraoperative complications and all patients had evidence of complete atrial appendage occlusion on intraoperative transesophageal echocardiogram. Performing LAAO did not significantly increase operative time compared to CSS implantation without concomitant LAAO. Median postoperative length of stay was 12 [10-13] days. During a total of 587 patient-days of follow-up, one patient suffered a non-disabling thrombotic stroke with no residual defects and one patient died from unrelated causes. LAAO is feasible via the left thoracotomy incision during CSS LVAD implantation. Early evidence suggests the procedure is safe and effective at occluding the left atrial appendage. Further research is needed to determine potential long-term benefits.

The Effect of Left Thoracotomy LVAD Implantation to LVAD Surgery and Followed Heart Transplantation Surgery

Left ventricular assist device (LVAD) implantations have traditionally been approached via full median sternotomy (FS). Recently, minimally invasive left thoracotomy (LT) approach has been popularized with improved surgical technique and emergence of smaller centrifugal LVAD devices. However, the surgical outcomes from minimal surgical approach remains to be unclear. The primary objective was to compare outcomes among patients who received an LVAD via FS compared to LT as well as their subsequent outcomes following heart transplantation. This is a single center retrospective study. 126 patients who underwent primary LVAD implantation from Jan 2014 to June 2018 are included (FS group n=83, LT group n=43). 49 patients had following HT (FS group n=27, LT group n=22). Preoperative patient demographics, intraoperative variables, hospital stay, postoperative survival and complications from LVAD implantation and heart transplantation were analyzed. Preoperatively, FS group had higher right atrial pressure (p<0.05). Intraoperative data showed LT group had 24% longer LVAD implant surgical time (p<0.05). Kaplan Meier curve showed better survival in LT group after LVAD implantation (p=0.04). The 1 year survival rate after heart transplantation was 100% for both groups. For post LVAD complications, FS group had more gastrointestinal bleeding events (p<0.05). There were no significant differences in post heart transplantation complications. Lastly, average length of hospital stay after LVAD implantation and heart transplantation showed no significance, respectively (25.0±24.9 vs 19.3±12.0, p=0.18),(28.2±41.9 vs 21.1± 13.7, p=0.46). Our study showed LT group was associated with improved survival after LVAD implantation. However, our study has limitation of containing bias from retrospective, non-randomized study design. Further, larger studies are warranted to prove the effects of minimally invasive LVAD implantation surgery.

Outcomes of obese patients undergoing less invasive LVAD implantation.

Obesity and heart failure rates continue to rise, confronting heart failure centers with challenging left ventricular assist device (LVAD) implantations. Although less invasive approaches to implantation have been successfully implemented by many centers, this surgical approach has not yet been well evaluated in the obese population. Therefore, we sought to describe our experience with less invasive device implantation in this patient cohort. All implants of centrifugal ventricular assist devices were retrospectively reviewed. Patients implanted with a less invasive approach via a left thoracotomy and upper hemisternotomy were included. Patients were stratified by body mass index (<30 vs ≥30 kg/m2 ). Perioperative and short-term outcomes were evaluated. Forty-two patients implanted with the less invasive approach (BMI <30: 27 vs. BMI ≥30 kg/m2 : 15) were identified. The obese cohort was significantly younger (58.5 vs 46.1 years, P = .022), while other preoperative demographics were similar. Postoperative mechanical ventilator time was longer in the obese cohort (22.9 vs 46.1 hour, P = .045). However, other perioperative and short-term outcomes were comparable. Wound dehiscence occurred in one obese patient. Six-month survival was also comparable between cohorts (96.3% vs 86.7%, P = .264). In this limited patient series, outcomes appear to be comparable in nonobese and obese patients undergoing less invasive LVAD implantation. Therefore, obesity should perhaps not be viewed as a lone contraindication to the application of this surgical approach.