Obesity and outcomes after left ventricular assist device implantation: insights from the EUROMACS Registry.

OBJECTIVES: The objective was to analyse associations between obesity and outcomes after left ventricular assist device (LVAD) implantation. METHODS: A retrospective analysis of the EUROMACS Registry was performed. Adult patients undergoing primary implantation of a continuous-flow LVAD between 2006 and 2019 were included (Medtronic HeartWare® HVAD®, Abbott HeartMate II®, Abbott HeartMate 3™). Patients were classified into 4 different groups according to body mass index at the time of surgery (body mass index <20 kg/m2: n = 254; 20-24.9 kg/m2: n = 1281; 25-29.9 kg/m2: n = 1238; ≥ 30 kg/m2: n = 691). RESULTS: The study cohort was comprised of 3464 patients. Multivariable Cox proportional cause-specific hazards regression analysis demonstrated that obesity (body mass index ≥30 kg/m2) was independently associated with significantly increased risk of mortality (body mass index ≥30 vs 20-24.9 kg/m2: hazard ratio 1.36, 95% confidence interval 1.18-1.57, overall P < 0.001). Moreover, obesity was associated with significantly increased risk of infection and driveline infection. The probability to undergo heart transplantation was significantly decreased in obese patients (body mass index ≥30 vs 20-24.9 kg/m2: hazard ratio 0.59, 95% confidence interval 0.48-0.74, overall P < 0.001). CONCLUSIONS: Obesity at the time of LVAD implantation is associated with significantly higher mortality and increased risk of infection as well as driveline infection. The probability to undergo heart transplantation is significantly decreased. These aspects should be considered when devising a treatment strategy before surgery.

Incidence, clinical relevance and therapeutic options for outflow graft stenosis in patients with left ventricular assist devices.

OBJECTIVES: We reviewed our institutional experience with outflow graft stenosis (OGS) in 3 contemporary left ventricular assist devices (LVAD). METHODS: Data from 347 consecutive adult recipients of LVAD [Medtronic HVAD (n = 184, 53.0%), Abbott HeartMate II (n = 62, 17.9%) and Abbott HeartMate 3 (n = 101, 29.1%)] implanted between March 2006 and October 2019 were analysed retrospectively. Primary study end points were the incidence of OGS necessitating treatment and survival on LVAD support. RESULTS: During the study period, 17 patients (4.9%) developed OGS requiring treatment with a probability of 0.6% at 1 year, 1.9% at 2 years, 3.8% at 3 years, 4.7% at 4 years and 5.9% at 5 years of LVAD support. Notably, in 13.8% of patients, a compression-related narrowing of the outflow graft with a probability of 1.5% at 6 months, 1.8% 1 year, 6.0% at 2 years, 12.3% at 3 years, 15.4% at 4 years and 16.6% at 5 years of LVAD support with no difference between devices (P = 0.26) was observed. There was a trend towards increased risk of mortality with OGS (hazard ratio 2.21, 95% confidence interval 0.87-5.51; P = 0.09). OGS preferentially occurred in segments of the outflow graft covered by a protective coating. CONCLUSIONS: OGS is a rare but potentially lethal complication during LVAD support. Modifications of pump design and implant techniques may be needed because OGS preferentially occurs within covered portions of the outflow graft. Systematic screening may be warranted.

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.

Thrombolysis as first-line therapy for Medtronic/HeartWare HVAD left ventricular assist device thrombosis.

OBJECTIVES: We reviewed our institutional experience with intravenous thrombolysis (TL) as first-line therapy in patients with Medtronic/HeartWare HVAD left ventricular assist device pump thrombosis (PT). METHODS: From March 2006 to November 2018, 30 Medtronic/HeartWare HVAD left ventricular assist device patients had 48 PT events. We analysed outcomes with intravenous Alteplase as a first-line therapy for PT. Pump exchange or urgent heart transplantation was only considered after the failure of TL or existing contraindications to TL. RESULTS: TL was used as the first-line therapy in 44 PT events in 28 patients without a contraindication to TL. TL was successful in 61.4% of PT events. More than 1 cycle of TL was necessary in 55.6% of events. The combined success of TL and heart transplantation or device exchange was 81.8%. In 15.9% of events, PT was fatal. Causes of death were severe complications (9.1%) related to TL or discontinuation of therapy for multi-organ failure (6.8%). Intracranial bleeding and arterial thromboembolism were observed in 4.5% and 11.5% of the PT events after TL. CONCLUSIONS: Intravenous TL as a first-line therapy for PT in Medtronic/HeartWare HVAD patients can be a reasonable treatment option and does not preclude subsequent heart transplantation or device exchange. However, thromboembolic and bleeding complications are common. The decision to perform TL or device exchange should, therefore, be made on an individual basis after balancing the risks and benefits of different treatment approaches.

Blood stream infection and outcomes in recipients of a left ventricular assist device.

OBJECTIVES: Our aim was to investigate associations between blood stream infection [≥1 positive blood culture (BC)] and outcomes in recipients of a left ventricular assist device (LVAD). METHODS: We retrospectively analysed all adult recipients of a continuous-flow LVAD between 2006 and 2016 at the Division of Cardiac Surgery, Medical University of Vienna (n = 257; devices: Medtronic HeartWare® HVAD®, Abbott HeartMate II®, Abbott HeartMate 3™). The primary outcome was all-cause mortality during follow-up. Secondary outcomes included the risk of stroke and pump thrombus during follow-up as well as the probability of heart transplantation (HTx). Risk factors for the development of ≥1 positive BC were evaluated additionally. RESULTS: The incidence of ≥1 positive BC during the first year of LVAD support was 32.1% [95% confidence interval (CI) 26.4-37.9]. Multivariable Cox proportional cause-specific hazards regression analysis showed that a positive BC was associated with significantly increased all-cause mortality [hazard ratio (HR) 5.51, 95% CI 3.57-8.51; P < 0.001]. Moreover, a positive BC was associated with a significantly increased risk of stroke (HR 2.41, 95% CI 1.24-4.68; P = 0.010). There was no association with the risk of pump thrombus or the probability of HTx. Independent risk factors for a positive BC included preoperative albumin and extracorporeal membrane oxygenation/intra-aortic balloon pump support. CONCLUSIONS: Blood stream infection is common and associated with a significantly increased risk of all-cause mortality and stroke at any given time during LVAD support. Effective strategies of prevention and treatment are necessary.

Impact of Bleeding Revision on Outcomes After Left Ventricular Assist Device Implantation.

BACKGROUND: Few reports have described associations between a bleeding revision and outcomes after implantation of a continuous-flow left ventricular assist device (LVAD). METHODS: We retrospectively analyzed all adult recipients of a continuous-flow LVAD who were operated on between January 2006 and December 2016 at the Division of Cardiac Surgery, Medical University of Vienna (N = 257). LVAD types were HeartWare HVAD (Medtronic, Minneapolis, MN), HeartMate II (Abbott [Thoratec], Abbott Park, IL), and HeartMate 3 (Abbott [Thoratec]). The primary outcome variable was survival during LVAD support. Secondary outcome variables were rates of prolonged ventilation, intensive care unit stay, hospital stay, renal replacement therapy, and stroke. We additionally investigated risk factors for a bleeding revision. RESULTS: Thirty-six patients (14%) underwent surgical revision for bleeding. In a multivariable Cox proportional hazards model, bleeding revision was associated with significantly reduced survival during LVAD support (3 months: hazard ratio [HR], 2.04; 95% confidence interval [CI], 1.20 to 3.48; 6 months: HR, 1.63; 95% CI, 0.95 to 2.82; 12 months: HR, 1.30; 95% CI, 0.69 to 2.46; 24 months: HR, 1.04; 95% CI 0.48 to 2.26; overall p = 0.007). Rates of secondary outcome variables were substantially higher in the revision group compared with patients who survived the hospital stay without a bleeding revision. Concomitant implantation of a temporary right ventricular assist device (p = 0.002) and age (p = 0.028) were independent risk factors for a bleeding revision. CONCLUSIONS: A bleeding revision is associated with significantly reduced survival and substantially increased morbidity during LVAD support. Preoperative, intraoperative, and postoperative prophylactic strategies may help to prevent this life-threatening complication.

Minimally invasive approaches for implantation of left ventricular assist devices.

The era of intracorporal continuous flow pumps has initiated significant success of left ventricular assist device (LVAD) surgery. However, median sternotomy has been the only surgical approach for implantation over many years. During the last decade, less-invasive access ways gained popularity. Within this review, we describe our own clinical experience in minimally invasive ventricular assist device (VAD) surgery and summarize the current scientific literature on this topic.

Long-term heart transplant outcomes after lowering fixed pulmonary hypertension using left ventricular assist devices.

OBJECTIVES: Fixed pulmonary hypertension (fPH) is a contraindication for heart transplantation (HTX). Left ventricular assist device (LVAD) implantation as a bridge to candidacy can reverse fPH in patients with terminal heart failure by chronic left ventricular unloading. We report our institutional experience with terminal heart failure patients and fPH that were successfully bridged to candidacy and underwent subsequent HTX. METHODS: We retrospectively reviewed the data of 79 patients with terminal heart failure and fPH who were successfully bridged to candidacy for HTX with 6 different LVAD devices at our centre from October 1998 to September 2016 (Novacor n = 4, MicroMed DeBakey n = 29, DuraHeart n = 2, HeartMate II n = 14, HVAD n = 29 and MVAD n = 1). Median duration of LVAD support was 288 days (range 45-2279 days). Within the same timeframe, a control group of 48 patients underwent HTX after bridge-to-transplant LVAD therapy for reasons other than PH. Study end points were (i) development of fPH after LVAD implantation, (ii) post-transplant outcomes and (iii) incidence of severe adverse events. RESULTS: Pulmonary vascular resistance, assessed by vasodynamic catheterization, was 4.3 ± 1.8 WU before LVAD implantation. After a median support period of 89 days (interquartile range 4-156 days), pulmonary vascular resistance decreased to 2.0 ± 0.9 WU (P ≤ 0.001), and patients were listed for HTX. Median duration of LVAD support in the study group was 288 days (45-2279 days). We observed 2 patients (2.5%) with acute right heart failure who required extracorporeal mechanical support after HTX in the study group. Long-term post-transplant survival between the study group (3 years: 83.5%, 5 years: 81.0%) and the control group (3 years: 87.5%, 5 years: 85.4%) was comparable (log-rank: P = 0.585). CONCLUSIONS: LVAD implantation as a bridge to candidacy reverses fPH in patients with terminal heart failure. Post-HTX survival is excellent and comparable to results obtained in patients without fPH at the time of HTX listing.

Use of the Novel Surgical Enhancement Tools for Less Invasive Abbott HeartMate 3 Implantation.

This report presents an initial experience with the novel Abbott surgical enhancement tools for less invasive HeartMate 3 (Abbott, Chicago, IL) left ventricular assist system implantation. Three new devices are introduced: (1) a mini-apical cuff with (2) a cuff holder and (3) a newly designed coring knife, facilitating access through a left sided minithoracotomy.

Tricuspid valve replacement: results of an orphan procedure - which is the best prosthesis?

BACKGROUND: Replacement of the tricuspid valve is uncommon. Prostheses specifically designed for this position are not available. Bovine, porcine as well as mechanical valve prostheses are currently used, however, the most suitable prosthesis type has not been defined. METHODS: We retrospectively analyzed all consecutive patients who underwent tricuspid valve replacement (TVR) at the Medical University of Vienna from 1996 to 2014. Baseline patient characteristics, prosthesis type, and postoperative outcome data were collected. RESULTS: A total of 58 patients underwent TVR. Forty-one patients (71%) received biological (18 bovine, 23 porcine), and 17 patients (29%) mechanical prostheses. One-year survival (70.2% vs. 76.5%, P=0.18), and freedom from reoperation at one year (86.3% vs. 94.1%, P=0.35) was not significantly different bioprostheses and mechanical valves. Freedom from reoperation rates for bovine versus porcine prostheses (one-year: 88.2% vs. 84.4%, P=0.145) were also not significantly different. However, three bovine prosthesis had to be reoperated due to high-grade central regurgitation without any signs of endocarditis or structural valve degeneration. CONCLUSIONS: There is a lack of clinical trials on tricuspid valve replacement and no specific guidelines for the choice of prosthesis. In the current study we have not identified significant differences in mortality between mechanical and biological valves. However, bovine prostheses seem less suitable for the tricuspid position due to the high closing volume with consecutive severe postoperative regurgitation.

Extracorporeal membrane oxygenation support for right ventricular failure after left ventricular assist device implantation.

OBJECTIVES: Right ventricular (RV) failure complicating left ventricular assist device implantation is associated with increased mortality. Despite a lack of supporting evidence, venoarterial extracorporeal membrane oxygenation (ECMO) support is increasingly being used as an alternative to traditional temporary RV support. We report our institutional experience with ECMO-facilitated RV support after left ventricular assist device implantation. METHODS: We retrospectively reviewed the concept of temporary ECMO support for perioperative RV failure in 32 consecutive left ventricular assist device (mean age 52 ± 14 years; male 84.4%; ischaemic cardiomyopathy 40.6%; INTERMACS Level I 71.8%; INTERMACS Level II 6.3%; INTERMACS Level III 12.5%; INTERMACS Level IV-VII 9.4%; HeartWare ventricular assist device 75%; HeartMate II: 25%) from May 2009 to April 2014. The study end points were RV recovery during ECMO support, mortality and causes of death. RESULTS: Twenty-nine (90.6%) patients were successfully weaned from ECMO support after RV recovery. Three (9.4%) patients expired during ECMO support. ECMO support improved RV function and haemodynamic parameters (central venous pressure 13 mmHg vs 10 mmHg, P < 0.01; mean pulmonary artery pressure 28 mmHg vs 21 mmHg, P < 0.01; cardiac output 5.1 l/min vs 5.9 l/min, P = 0.09) over a median period of 3 (range 1-15) days. Thirty-day and in-hospital mortality were 18.8% and 25%, respectively. One-year survival was 75%, causes of death were multiorgan dysfunction syndrome (50%), sepsis (25%), haemorrhagic stroke (12.5%) and ischaemic stroke (12.5%). Causes of death during ECMO support were ischaemic stroke, sepsis and multiorgan dysfunction syndrome. CONCLUSIONS: Temporary ECMO-facilitated RV support is associated with good long-term outcomes and high rates of RV recovery.

High-Intensity Transient Signals in the Outflow Graft and Thrombosis of a HeartWare Left Ventricular Assist Device.

We report the echocardiographic detection of microbubbles in the outflow prosthesis of a HeartWare HVAD left ventricular assist device using transthoracic echocardiography. In this case it was a specific sign associated with device thrombosis that resolved after successful treatment with systemic thrombolysis.