The utility of temporal trends of blood biomarkers as predictors for bloodstream infections in left ventricular assist device recipients.

BACKGROUND: Temporal trends of routinely obtained parameters may provide valuable information for predicting BSIs, but this association has not yet been established in LVAD patients. METHODS: This retrospective analysis included data from 347 consecutive recipients of three rotary LVAD types. Study endpoints included the incidence of BSI, the association of temporal trends of routinely obtained blood biomarkers with the development of BSIs, the incidence of BSIs, and survival on LVAD support. RESULTS: During follow-up, 47.8% (n = 166) of the patients developed BSI. In multivariate analyses, the development of BSI was a significant predictor of mortality (HR 5.78, 95% CI 4.08-8.19, p < 0.0001). In univariate analyses, after adjusting for potential confounders, albumin (SHR 0.94, 95% CI 0.91-0.97, p < 0.00010), creatinine (SHR 1.49, 95% CI 1.03-2.15, p = 0.033), and C-reactive protein (SHR 1.19, 95% CI 1.08-1.32, p = 0.0007) significantly predicted the development of BSIs during LVAD support. Notably, the strength of the association of parameter changes with the prediction of BSIs demonstrated a time-dependent correlation in the cases of albumin (p = 0.045) and creatinine (p = 0.003). CONCLUSION: Bloodstream infections are highly prevalent among LVAD recipients and are independent predictors of mortality. Temporal biomarker trends significantly predict the development of BSIs. These findings suggest opportunities for interventions aiming to reduce the incidence of BSIs.

Preoperative anatomical landmarks and longitudinal HeartMate 3 pump position in X-rays: Relevance for adverse events.

BACKGROUND: Left ventricular assist device (LVAD) malposition has been linked to hemocompatibility-related adverse events (HRAEs). This study aimed to identify preoperative anatomical landmarks and postoperative pump position, associated with HRAEs during LVAD support. METHODS: Pre- and postoperative chest X-ray measures (≤14 days pre-implantation, first postoperative standing, 6, 12, 18, and 24 months post-implantation) were analyzed for their association with HRAEs over 24 months in 33 HeartMate 3 (HM3) patients (15.2% female, age 66 (9.5) years). RESULTS: HM3 patients with any HRAE showed significantly lower preoperative distances between left ventricle and thoracic outline (dLVT) (25.3 ± 10.2 mm vs. 40.3 ± 15.5 mm, p = 0.004). A ROC-derived cutoff dLVT ≤ 29.2 mm provided 85.7% sensitivity and 72.2% specificity predicting any HRAE during HM3 support (76.2% (>29.2 mm) vs. 16.7% (≤29.2 mm) freedom from HRAE, p < 0.001) and significant differences in cardiothoracic ratio (0.58 ± 0.04 vs. 0.62 ± 0.04, p = 0.045). Postoperative X-rays indicated lower pump depths in patients with ischemic strokes (9.1 ± 16.2 mm vs. 38.0 ± 18.5 mm, p = 0.007), reduced freedom from any neurological event (pump depth ≤ 28.7 mm: 45.5% vs. 94.1%, p = 0.004), and a significant correlation between pump depth and inflow cannula angle (r = 0.66, p < 0.001). Longitudinal changes were observed in heart-pump width (F(4,60) = 5.61, p < 0.001). CONCLUSION: Preoperative X-ray markers are associated with postoperative HRAE occurrence. Applying this knowledge in clinical practice may enhance risk stratification, guide therapy optimization, and improve HM3 recipient management.

Anesthetic practice during cardiac implantable electronic device implant procedures: A retrospective, single-center study.

Objectives: Data on anesthetic proceedings during cardiac implantable electronic device (CIED) implant procedures are scarce and it remains unclear whether anesthetic care is still required in selected patients. Methods: In this retrospective, single center study we assessed the prevalence of intraoperative anesthetic management comprising anesthetic standby, sedation or general anesthesia as well as anesthetic and procedural complications. We analyzed pre-existing and perioperative risk factors related to procedure-related adverse outcome such as perioperative cardiopulmonary resuscitation (CPR) and 30-day mortality in a uni- and multivariable analysis. Results: In total, PM and ICD insertion were performed in up to 85% and 58% under anesthetic standby, with an increasing tendency over time.Overall, Cardiopulmonary resuscitation (CPR) was required in 59 patients. Acute heart failure (AHF) was the only independent pre-existing risk factor for CPR and for 30-day mortality. Sedation and general anesthesia had a significantly increased odds ratio for CPR compared to anesthetic standby. The risk for CPR significantly decreased during the study period. Conclusions: Over the years anesthetic practice during CIED implant procedures shifted from mixed anesthetic proceedings to mainly standby duties. The prevalence of complications and emergency measures is low, however not uncommon. Accordingly, the presence of an anesthesiologist should be further guaranteed when sedatives were titrated and in AHF patients. However, in patients receiving local anesthetic infiltration only, it seems safe to perform CIED implant procedures without anesthetic standby.

The effect of occlusive polytetrafluoroethylene outflow graft protectors in left ventricular assist device recipients.

BACKGROUND: The use of polytetrafluoroethylene (PTFE) material as a protective cover for left ventricular assist device (LVAD) outflow grafts (OG) is a common practice. However, it has descriptively been linked to the development of blood flow obstruction (BFO). METHODS: Patient data from 194 consecutive HVAD (Medtronic Inc; Medtronic, Minneapolis, MN) recipients implanted between March 2006 and January 2021 were retrospectively analyzed. PTFE covers were used in 102 patients. Study outcomes included the incidence of BFO and survival on LVAD support. RESULTS: Thirty-seven patients (19.1%) developed BFO during the study period. On a multivariable Cox regression analysis, PTFE use was an independent predictor for the development of BFO (HR 2.15, 95% CI 1.03-4.48, p = .04). BFO comprised of 2 types of device malfunction: eleven patients (5.7%) developed outflow graft stenosis (OGS), and 31 patients (16.0%) developed pump thrombosis (PT). There was a significantly higher cumulative incidence of OGS in patients with PTFE cover than in those without (Gray's test, p =.03). However, the observed higher cumulative incidence of PT in PTFE patients was non-significant (Gray's test, p =.06). In a multivariable Cox regression model, the effect of PTFE use on survival was non-significant (HR 0.95, 95% CI 0.60-1.48, p =.81), while the development of BFO was independently associated with increased mortality (HR 3.43, 95% CI 1.94-6.06, p < .0001). CONCLUSIONS: The use of PTFE OG cover in LVAD patients is associated with an increased cumulative probability of development of BFO, the latter adversely impacting survival and is therefore, harmful.

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.

Validation of Intrinsic Left Ventricular Assist Device Data Tracking Algorithm for Early Recognition of Centrifugal Flow Pump Thrombosis.

Advanced stage heart failure patients can benefit from the unloading effects of an implantable left ventricular assist device. Despite best clinical practice, LVADs are associated with adverse events, such as pump thrombosis (PT). An adaptive algorithm alerting when an individual's appropriate levels in pump power uptake are exceeded, such as in the case of PT, can improve therapy of patients implanted with a centrifugal LVAD. We retrospectively studied 75 patients implanted with a centrifugal LVAD in a single center. A previously optimized adaptive pump power-tracking algorithm was compared to clinical best practice and clinically available constant threshold algorithms. Algorithm performances were analyzed in a PT group (n = 16 patients with 30 PT events) and a thoroughly selected control group (n = 59 patients, 34.7 patient years of LVAD data). Comparison of the adaptive power-tracking algorithm with the best performing constant threshold algorithm resulted in sensitivity of 83.3% vs. 86.7% and specificity of 98.9% vs. 95.3%, respectively. The power-tracking algorithm produced one false positive detection every 11.6 patient years and early warnings with a median of 3.6 days prior to PT diagnosis. In conclusion, a retrospective single-center validation study with real-world patient data demonstrated advantageous application of a power-tracking algorithm into LVAD systems and clinical practice.

Inflow cannula position as risk factor for stroke in patients with HeartMate 3 left ventricular assist devices.

BACKGROUND: A relation between the left ventricular assist device inflow cannula (IC) malposition and pump thrombus has been reported. This study aimed to investigate if the pump position, derived from chest X-rays in HeartMate 3 (HM3) patients, correlates with neurological dysfunction (ND), ischemic stroke (IS), hemorrhagic stroke (HS) and survival. METHODS: This analysis was performed on routinely acquired X-rays of 42 patients implanted with a HM3 between 2014 and 2017. Device position was quantified in patients with and without ND from frontal and lateral X-rays characterizing the IC and pump in relation to spine, diaphragm or horizontal line. The primary end-point was freedom from stroke and survival one-year after HM3 implantation stratified by pump position. RESULTS: The analysis of X-rays, 33.5 (41.0) days postoperative, revealed a significant smaller IC angle of HM3 patients with ND versus no ND (0.1° ± 14.0° vs. 12.9° ± 10.1°, p = 0.005). Additionally, the IC angle in the frontal view, IS: 4.1 (20.9)° versus no IS: 13.8 (7.5)°, p = 0.004 was significantly smaller for HM3 patients with IS. Using receiver operating characteristics derived cut-off, IC angle <10° provided 75% sensitivity and 100% specificity (C-statistic = 0.85) for predicting IS. Stratified by IC angle, freedom from IS at 12 months was 100% (>10°) and 60% (<10°) respectively (p = 0.002). No significant differences were found in any end-point between patients with and without HS. One-year survival was significantly higher in patients with IC angle >10° versus <10° (100% vs. 71.8%, p = 0.012). CONCLUSIONS: IC malposition derived from standard chest X-rays serves as a risk factor for ND, IS and worse survival in HM3 patients.

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.

International Normalized Ratio Test Frequency in Left Ventricular Assist Device Patients Affects Anticoagulation Quality and Adverse Events.

Anticoagulation therapy in patients using left ventricular assist device (LVAD) is essential to reduce hemocompatibility related adverse events (HRAEs). Vitamin K-antagonist dosage must be adapted and monitored by INR point-of-care testing (POCT) in outpatients. The study aims to determine if the frequency of INR POCT in LVAD outpatients has an influence on the quality of anticoagulation therapy (ACQ), HRAEs, and outcomes. This retrospective study included n = 48 patients who received LVAD implantation (HMII, HM3, and HVAD) between 2013 and 2017. ACQ (% of INR tests in range, PTR), outcomes and HRAEs using Kaplan-Meier curves were compared in a daily (n = 36) and 3×/week (n = 12) INR POCT group. Further, based on the achieved PTR ranging from 0-60% (poor), 61-70% (acceptable), and 71-100% (well controlled), HRAEs and outcomes were compared. Daily and 3×/week groups were similar in perioperative risk factors and INR target (p = 0.28). Freedom from any HRAE (38.9% vs. 25.0%, p = 0.44), any readmission (72.2% vs. 75.0%, p = 0.97), and 1 year survival (91.7% vs. 91.7%, p = 0.98) were comparable in both groups. The PTR was significantly higher with the daily self-assessments (73.5% vs. 68.4%, p = 0.006). Well vs. poorly controlled INR POCT patients more often had (p = 0.01) a daily POCT frequency (92%) vs. poorly controlled (54%) and significantly higher freedom from neurologic events (96.0 vs. 69.2%, p = 0.024) as well as hemorrhagic strokes (100% vs. 76.9%, p = 0.011). Well-controlled anticoagulation of LVAD outpatients is associated with less neurologic events. The frequency of INR POCT could be one of the key factors in the reduction of HRAEs, so future prospective, large-scale studies should help to clarify the effects.

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.

Hemodynamic exercise responses with a continuous-flow left ventricular assist device: Comparison of patients' response and cardiorespiratory simulations.

BACKGROUND: Left ventricular assist devices (LVADs) are an established treatment for end stage heart failure patients. As LVADs do not currently respond to exercise demands, attention is also directed towards improvements in exercise capacity and resulting quality of life. The aim of this study was to explore hemodynamic responses observed during maximal exercise tests to infer underlying patient status and therefore investigate possible diagnostics from LVAD derived data and advance the development of physiologically adaptive LVAD controllers. METHODS: High resolution continuous LVAD flow waveforms were recorded from 14 LVAD patients and evaluated at rest and during maximum bicycle exercise tests (n = 24). Responses to exercise were analyzed in terms of an increase (↑) or decrease (↓) in minimum (QMIN), mean (QMEAN), maximum flow (QMAX) and flow pulsatility (QP2P). To interpret clinical data, a cardiorespiratory numerical simulator was used that reproduced patients' hemodynamics at rest and exercise. Different cardiovascular scenarios including chronotropic and inotropic responses, peripheral vasodilation, and aortic valve pathologies were simulated systematically and compared to the patients' responses. RESULTS: Different patients' responses to exercise were observed. The most common response was a positive change of ΔQMIN↑ and ΔQP2P↑ from rest to exercise (70% of exercise tests). Two responses, which were never reported in patients so far, were distinguished by QMIN↑ and QP2P↓ (observed in 17%) and by QMIN↓ and QP2P↑ (observed in 13%). The simulations indicated that the QP2P↓ can result from a reduced left ventricular contractility and that the QMIN↓ can occur with a better left ventricular contractility and/or aortic insufficiency. CONCLUSION: LVAD flow waveforms determine a patients' hemodynamic "fingerprint" from rest to exercise. Different waveform responses to exercise, including previously unobserved ones, were reported. The simulations indicated the left ventricular contractility as a major determinant for the different responses, thus improving patient stratification to identify how patient groups would benefit from exercise-responsive LVAD control.

Continuous LVAD monitoring reveals high suction rates in clinically stable outpatients.

Suction of the left ventricle can lead to potentially life-threatening events in left ventricular assist device (LVAD) patients. With the resolution of currently available clinical LVAD monitoring healthcare professionals are unable to evaluate patients' suction occurrences in detail. This study investigates occurrences and durations of suction events and their associations with tachycardia in stable outpatients. Continuous high-resolution LVAD data from HVAD patients were analyzed in the early outpatient period for 15 days. A validated suction detection from LVAD signals was used. Suction events were evaluated as suction rates, bursts of consecutive suction beats, and clusters of suction beats. The occurrence of tachycardia was analyzed before, during, and after suction clusters. Furthermore, blood work, implant strategy, LVAD speed setting, inflow cannula position, left ventricular diameters, and adverse events were evaluated in these patients. LVAD data of 10 patients was analyzed starting at 78 ± 22 postoperative days. Individuals' highest suction rates per hour resulted in a median of 11% (range 3%-61%). Bursts categorized as consecutive suction beats with n = 2, n = 3-5, n = 6-15, and n > 15 beats were homogenously distributed with 10.3 ± 0.8% among all suction beats. Larger suction bursts were followed by shorter suction-free periods. Tachycardia during suction occurred in 12% of all suction clusters. Significant differences in clinical parameters between individuals with high and low suction rates were only observed in left ventricular end-diastolic and end-systolic diameters (P < .02). Continuous high-resolution LVAD monitoring sheds light on outpatient suction occurrences. Interindividual and intraindividual characteristics of longitudinal suction rates were observed. Longer suction clusters have higher probabilities of tachycardia within the cluster and more severe types of suction waveforms. This work shows the necessity of improved LVAD monitoring and the implementation of an LVAD speed control to reduce suction rates and their concomitant burden on the cardiovascular system.

Early Detection of Pump Thrombosis in Patients With Left Ventricular Assist Device.

Pump thrombosis (PT) is a serious adverse event in patients receiving left ventricular assist devices (LVAD). The study aims to determine whether pump parameters and clinical data may enable early detection of PT. This retrospective study included 88 patients who received an LVAD between 2012 and 2015 among which those with intra-PT were identified. In a propensity score-matched control group observation, time periods were matched with time before thrombosis. International normalized ratio (INR) time in therapeutic range (TTR) and lactate dehydrogenase (LDH) were analyzed for 60 days preceding PT. Furthermore, pump data (power, flow, and speed) in HeartWare ventricular assist devices (HVAD) patients were analyzed 7 days before PT using a mixed-design analysis of variance to investigate temporal changes in pump data. Pump thrombosis occurred in 15 patients (13 males, age 58 ± 10 years, 7 HeartMate II and 8 HVAD). International normalized ratio therapeutic range (2.0-3.0) and acetylsalicylic acid daily doses (100-200 mg) were similar for both groups, but patients with PT had lower TTR (36% vs. 65%; p = 0.025). No significant difference in LVAD power between groups was seen at baseline (p = 0.31), and power did not change in the control group over time (p > 0.99). Lactate dehydrogenase increased already 1 week prior PT and power from 4.4 ± 0.8 W at baseline to 4.9 ± 0.8 W (p = 0.007) 2 days before readmission and to 6.5 ± 1.8 W (p = 0.015) at readmission. Pump thrombosis is associated with a lower percentage of INR TTR and elevated LDH before the event. A better monitoring of pump parameters would enable PT detection already up to 2 days in advance.

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.

A Standardized Telephone Intervention Algorithm Improves the Survival of Ventricular Assist Device Outpatients.

Ventricular assist devices (VADs) are an established therapeutic option for patients with chronic heart failure. Continuous monitoring of VAD parameters and their adherence to guidelines are crucial to detect problems in an early stage to optimize outcomes. A telephone intervention algorithm for VAD outpatients was developed, clinically implemented and evaluated. During the phone calls, a structured inquiry of pump parameters, alarms, blood pressure, INR, body weight and temperature, exit-site status and heart failure symptoms was performed and electronically categorized by an algorithm into 5 levels of severity. VAD outpatient outcomes without (n = 71) and with bi-weekly telephone interviews in their usual care (n = 25) were conducted using proportional hazard Cox regression, with risk adjustment based on a propensity score model computed from demographics and risk factors. From February 2015 through October 2017, 25 patients (n = 3 HeartMate II, n = 4 HeartMate 3 and n = 18 HeartWare HVAD) underwent 637 telephone interventions. In 57.5% of the calls no problems were identified, 3.9% were recalled on the next day because of alarms. In 26.5% (n = 169), the VAD Coordinator had to refer to the physician due to elevated blood pressure (n = 125, >85 mm Hg), INR < 2.0 or > 4.0 (n = 24) or edema (n = 10), 11.9% of the calls led to a follow-up because of equipment or exit-site problems. Propensity-adjusted 2-year survival (89% vs. 57%, P = 0.027) was significantly higher for the telephone intervention group. Continuous, standardized communication with VAD outpatients is important for early detection of upcoming problems and leads to significantly improved survival.