Mechanical Circulatory Support Systems in Fulminant Myocarditis: Recent Advances and Outlook

Background: Fulminant myocarditis (FM) constitutes a severe and life-threatening form of acute cardiac injury associated with cardiogenic shock. The condition is characterised by rapidly progressing myocardial inflammation, leading to significant impairment of cardiac function. Due to the acute and severe nature of the disease, affected patients require urgent medical attention to mitigate adverse outcomes. Besides symptom-oriented treatment in specialised intensive care units (ICUs), the necessity for temporary mechanical cardiac support (MCS) may arise. Numerous patients depend on these treatment methods as a bridge to recovery or heart transplantation, while, in certain situations, permanent MCS systems can also be utilised as a long-term treatment option. Methods: This review consolidates the existing evidence concerning the currently available MCS options. Notably, data on venoarterial extracorporeal membrane oxygenation (VA-ECMO), microaxial flow pump, and ventricular assist device (VAD) implantation are highlighted within the landscape of FM. Results: Indications for the use of MCS, strategies for ventricular unloading, and suggested weaning approaches are assessed and systematically reviewed. Conclusions: Besides general recommendations, emphasis is put on the differences in underlying pathomechanisms in FM. Focusing on specific aetiologies, such as lymphocytic-, giant cell-, eosinophilic-, and COVID-19-associated myocarditis, this review delineates the indications and efficacy of MCS strategies in this context.

HeartMate 3 Snoopy: Noninvasive cardiovascular diagnosis of patients with fully magnetically levitated blood pumps during echocardiographic speed ramp tests and Valsalva maneuvers

PURPOSE

The HeartMate 3 (HM3) left ventricular assist device (LVAD) has demonstrated excellent clinical outcomes; however, pump speed optimization is challenging with the available HM3 monitoring. Therefore, this study reports on clinical HM3 parameters collected with a noninvasive HM3 monitoring system (HM3 Snoopy) during echocardiographic speed ramp tests and Valsalva maneuvers.

METHODS

In this prospective, single-center study, the HM3 data communication between the controller and pump was recorded with a novel data acquisition system. Twelve pump parameters sampled every second (1 Hz) and clinical assessments (echocardiography, electrocardiogram (ECG), and blood pressure measurement) during speed ramp tests were analyzed using Pearson's correlation (r, median [IQR]). The cause for the occurrence of pulsatility index (PI)-events during ramp speed tests and valsalva maneuvers was investigated.

RESULTS

In 24 patients (age: 58.9 ± 8.8 years, body mass index: 28.1 ± 5.1 kg/m2, female: 20.8%), 35 speed ramp tests were performed with speed changes in the range of ±1000 rpm from a baseline speed of 5443 ± 244 rpm. Eight HM3 pump parameters from estimated flow, motor current, and LVAD speed together with blood pressure showed positive collinearities (r = 0.9 [0.1]). Negative collinearities were observed for pump flow pulsatility, pulsatility index, rotor noise, and left ventricular diameters (r = -0.8 [0.1]), whereas rotor displacement and heartrate showed absence of collinearities (r = -0.1 [0.08]).

CONCLUSIONS

In this study, the HM3 Snoopy was successfully used to acquire more parameters from the HM3 at a higher sampling rate. Analysis of HM3 per-second data provide additional clinical diagnostic information on heart-pump interactions and cause of PI-events.

Outcome of patients supported with the HeartMate 3 after extracorporeal life support: On behalf of the Durable Mechanical Circulatory Support After Extracorporeal Life Support Study Group

OBJECTIVES

The Durable Mechanical Circulatory Support System After Extracorporeal Life Support registry is a multicenter registry of patients who were bridged from extracorporeal life support to a durable mechanical circulatory support system. Although numerous studies have highlighted the favorable outcomes after implantation of the HeartMate 3 (Abbott), the objective of our study is to examine the outcomes of patients who received HeartMate 3 support after extracorporeal life support.

METHODS

Data of patients undergoing HeartMate 3 implantation from January 2016 to April 2022 at 14 centers were collected and evaluated. Inclusion criteria were patients with extracorporeal life support before HeartMate 3 implantation. The outcome was reported and compared with patients receiving other types of pumps.

RESULTS

A total of 337 patients were bridged to durable mechanical circulatory support system after extracorporeal life support in the study period. Of those patients, 140 were supported with the HeartMate 3. The other types of pumps included 170 HeartWare HVADs (Medtronic) (86%), 14 HeartMate II devices (7%), and 13 (7%) other pumps (7%). Major postoperative complications included right heart failure requiring temporary right ventricular assist device in 60 patients (47%). Significantly lower postoperative stroke (16% vs 28%, P = .01) and pump thrombosis (3% vs 8%, P = .02) rates were observed in the patients receiving the HeartMate 3. The 30-day, 1-year, and 3-year survivals in patients receiving the HeartMate 3 were 87%, 73%, and 65%, respectively.

CONCLUSIONS

In this critically ill patient population, the survivals of patients who were transitioned to the HeartMate 3 are deemed acceptable and superior to those observed when extracorporeal life support was bridged to other types of durable mechanical circulatory support systems.

Quality of Anticoagulation With Phenprocoumon and Warfarin in Left Ventricular Assist Device Patients: A Multicenter Study

VISUAL ABSTRACT

of key results. INR, international normalized ratio; TTR, time in therapeutic range; PTR, percentage of tests in range; HRAE, hemocompatibility-related adverse event; FFUV, first follow-up visit; GIB, gastrointestinal bleeding; HR, hazard ratio.http://links.lww.com/ASAIO/A961.

Bleeding and thrombotic events in postcardiotomy extracorporeal life support

OBJECTIVES

Hemorrhagic and thrombotic complications are known obstacles in extracorporeal life support (ECLS), and patients requiring postcardiotomy ECLS are particularly prone. The objective of the study was to characterize incidence, type and clinical relevance of bleeding and thrombotic events on PC-ECLS.

METHODS

504 patients receiving PC-ECLS between 2000-2021 at a single center were included in a retrospective analysis. Incidence and type of hemorrhagic and thrombotic complications on PC-ECLS were assessed. Overall survival was compared and perioperative risk factors for bleeding and thrombotic events assessed by binary logistic regression.

RESULTS

Of 504 patients requiring PC-ECLS, 196 patients(38.9%) had 235 bleeding events (surgical site: n = 135(26.8%); cannulation site: n = 68(13.4%); requiring surgical revision, n = 39(7.7%) cannulation site change: n = 17(3.4%), fatal cannulation site bleeding: n = 4(0.8%); intracranial haemorrhage: n = 11(2.1%); gastrointestinal: n = 8(1.6%); pulmonary: n = 8(1.6%), and intra-abdominal/retroperitoneal: n = 5 (1%)). Overall mortality was higher in patients with major bleeding complications than in patients without bleeding complications (p < 0.0001).74 patients (14.7%) had 84 thrombotic events (ischaemic stroke n = 39 (7.7%); cannula/circuit thrombosis n = 26 (5.2%); peripheral embolism n = 11 (2.2%), device exchange for hemolysis n = 8 (1.6%)). 246 patients (48.8%) had at least one hemocompatibility-related adverse event. Preoperative dual antiplatelet therapy (adjusted OR: 1.83, 95% CI: 1.063-3.137) and ECLS duration (adjusted OR: 1.14, 95% CI: 1.086-1.197) were identified as independent risk factors for haemorrhage, and prior stroke/transient ischaemic attack (adjusted OR: 1.91, 95% CI: 1.08-3.83) and ECLS duration (adjusted OR: 1.09, 95% CI: 1.04-1.15) were identified as risk factors for thrombotic events.

CONCLUSIONS

Bleeding complications on ECLS are common and significantly impair survival. Nearly half of patients were affected by any hemocompatibility-related event.

Identifying patients at risk: multi-centre comparison of HeartMate 3 and HeartWare left ventricular assist devices

AIMS

Since the withdrawal of HeartWare (HVAD) from the global market, there is an ongoing discussion if and which patients require prophylactically exchange for a HeartMate 3 (HM3). Therefore, it is important to study outcome differences between HVAD and HM3 patients. Because centres differ in patient selection and standard of care, we performed a propensity score (PS)-based study including centres that implanted both devices and aimed to identify which HVAD patients are at highest risk.

METHODS AND RESULTS

We performed an international multi-centre study (n = 1021) including centres that implanted HVAD and HM3. PS-matching was performed using clinical variables and the implanting centre. Survival and complications were compared. As a sensitivity analysis, PS-adjusted Cox regression was performed. Landmark analysis with conditional survival >2 years was conducted to evaluate long-term survival differences. To identify which HVAD patients may benefit from a HM3 upgrade, Cox regression using pre-operative variables and their interaction with device type was performed. Survival was significantly better for HM3 patients (P < 0.01) in 458 matched patients, with a median follow-up of 23 months. Within the matched cohort, HM3 patients had a median age of 58 years, and 83% were male, 80% of the HVAD patients were male, with a median age of 59 years. PS-adjusted Cox regression confirmed a significantly better survival for HM3 patients when compared with HVAD, with a HR of 1.46 (95% confidence interval 1.14-1.85, P < 0.01). Pump thrombosis (P < 0.01) and ischaemic stroke (P < 0.01) occurred less in HM3 patients. No difference was found for haemorrhagic stroke, right heart failure, driveline infection, and major bleeding. Landmark-analysis confirmed a significant difference in conditional survival >2 years after implantation (P = 0.03). None of the pre-operative variable interactions in the Cox regression were significant.

CONCLUSIONS

HM3 patients have a significantly better survival and a lower incidence of ischaemic strokes and pump thrombosis than HVAD patients. This survival difference persisted after 2 years of implantation. Additional research using post-operative variables is warranted to identify which HVAD patients need an upgrade to HM3 or expedited transplantation.

Three-month outcomes after the implantation of two HeartMate 3 devices in total artificial heart configuration

BACKGROUND

Total artificial heart (TAH) implantation is a rarely performed procedure. Contrarily, left ventricular assist device (VAD) implantation is rather common in many centers. As transplantation is quantitatively limited cardiac replacement with artificial hearts is a viable alternative in the treatment of severe biventricular heart failure. An alternative to TAH is the implantation of two VADs in a TAH configuration. We hereby present the first multi-center study on 3-months outcomes of patients treated by cardiectomy and placement of two HeartMate 3s in a TAH configuration.

METHODS

We retrospectively investigated a cohort of 15 patients that underwent HM3-TAH-implantation at three international institutions. Follow-up was 3 months after implantation. Baseline, intra- and postoperative parameters as well as survival data and adverse events were collected.

RESULTS

A total of 1089 days on HM3-TAH were observed. Thirty-day survival after HM3-TAH implantation was 53% (8/15) and three month survival was 40% (6/15). The longest duration on device was 274 days. Causes of death were multi-organ failure, sepsis, and neurological adverse events. No technical complications were documented. Two patients remained on the device. Four patients (26%) were successfully bridged to transplantation.

CONCLUSIONS

The implantation of two HeartMate 3s in a TAH configuration is a last resort and off-label concept in cases of extreme biventricular heart failure. In a diligently selected patient cohort, HM3-TAH implantation is a feasible method to increase the chance of survival in a severely ill patient cohort and successfully bridge patients to heart transplantation that would otherwise have died.

It's not only the pump: Assessment of human factors of wearable components and user experience of patients with left ventricular assist devices

BACKGROUND

Despite design improvements in left ventricular assist devices (LVADs) over the past decade, limitations of external, wearable VAD components affect patient quality of life and safety. The aim of this study was to describe both user experience and human factor issues of 2 contemporary LVADs.

METHODS

This single-center, cross-sectional study included LVAD outpatients who were at least 3 months after implantation. Before developing the 16-item survey, a systematic literature review and 2-round Delphi method involving 9 VAD clinicians were used to select items in 6 domains: power supply, emergency situations, wearability, mobility, and freedom to travel, user modifications, lifestyle, and home adaptations.

RESULTS

Fifty-eight patients (61.6 ± 11.6 years, 13.8% female, HeartMate 3 (HM3)/HVAD: n = 39/19) completed the one-time survey after median of 853 days on device: 10.3% reported problems changing power supply, 12.7% unintentional driveline disconnection (HM3: 5.6% vs HVAD: 26.3%, p = 0.041). Against the recommendation 74.1% sleep with battery-support (HM3: 88.9% vs HVAD: 44.4%, p = 0.001). About 65.3% criticized the carry bag weight/size (HM3: 71.4% vs HVAD: 50.0%, p = 0.035), thus 24.1% wear an own carrying-system, 42.1% modified their wearables, 38.9% their clothing, and 65.3% their home to cope with life on LVAD support. Mobility is reduced due to limited wearability: 18.9% went abroad (only 3.7% by plane) and 40.0% use less public transport than before implantation (the older the less: r = -0.37, p = 0.013).

CONCLUSIONS

HVAD and HM3 wearables still show a variety of human factors issues and potential for improved user experience. User-centered design and incorporation of patient feedback may increase user satisfaction, and patient safety.

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.

When Nothing Goes Right: Risk Factors and Biomarkers of Right Heart Failure after Left Ventricular Assist Device Implantation

Right heart failure (RHF) is a severe complication after left ventricular assist device (LVAD) implantation. The aim of this study was to analyze the incidence, risk factors, and biomarkers for late RHF including the possible superiority of the device and implantation method. This retrospective, single-center study included patients who underwent LVAD implantation between 2014 and 2018. Primary outcome was freedom from RHF over one-year after LVAD implantation; secondary outcomes included pre- and postoperative risk factors and biomarkers for RHF. Of the 145 consecutive patients (HeartMate 3/HVAD: n = 70/75; female: 13.8%), thirty-one patients (21.4%) suffered RHF after a mean LVAD support of median (IQR) 105 (118) days. LVAD implantation method (less invasive: 46.7% vs. 35.1%, p = 0.29) did not differ significantly in patients with or without RHF, whereas the incidence of RHF was lower in HeartMate 3 vs. HVAD patients (12.9% vs. 29.3%, p = 0.016). Multivariate Cox proportional hazard analysis identified HVAD (HR 4.61, 95% CI 1.12–18.98; p = 0.03), early post-op heart rate (HR 0.96, 95% CI 0.93–0.99; p = 0.02), and central venous pressure (CVP) (HR 1.21, 95% CI 1.05–1.39; p = 0.01) as independent risk factors for RHF, but no association of RHF with increased all-cause mortality (HR 1.00, 95% CI 0.99–1.01; p = 0.50) was found. To conclude, HVAD use, lower heart rate, and higher CVP early post-op were independent risk factors for RHF following LVAD implantation.

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.

Driveline Features as Risk Factor for Infection in Left Ventricular Assist Devices: Meta-Analysis and Experimental Tests

Background: Risk factors for driveline infection (DLI) in patients with left ventricular assist devices are multifactorial. The aim of this study was to analyze the correlation between mechanical driveline features and DLI occurrence.

Methods: A meta-analysis was conducted that included studies reporting DLI rates at 6 months after implantation of any of three contemporary devices (HVAD with Pellethane or Carbothane driveline, HeartMate II, and HeartMate 3). Further, outer driveline diameter measurements and ex-vivo experimental three-point bending and torsion tests were performed to compare the stiffness of the four different driveline types.

Results: 21 studies with 5,393 patients were included in the meta-analysis. The mean weighted DLI rates ranged from 7.2% (HeartMate II) to 11.9% (HeartMate 3). The HeartMate II driveline had a significantly lower maximal bending force (Load_max) (4.52 ± 0.19 N) compared to the Carbothane HVAD (8.50 ± 0.08 N), the HeartMate 3 (11.08 ± 0.3 N), and the Pellethane HVAD driveline (15.55 ± 0.14 N) (p < 0.001). The maximal torque (Torque_max) of the HeartMate II [41.44 (12.61) mNm] and the Carbothane HVAD driveline [46.06 (3.78) mNm] were significantly lower than Torque_max of the Pellethane HVAD [46.06 (3.78) mNm] and the HeartMate 3 [95.63 (26.60) mNm] driveline (p < 0.001). The driveline of the HeartMate 3 had the largest outer diameter [6.60 (0.58) mm]. A relationship between the mean weighted DLI rate and mechanical driveline features (Torque_max) was found, as the the HeartMate II driveline had the lowest Torque_max and lowest DLI rate, whereas the HeartMate 3 driveline had the highest Torque_max and highest DLI rate.

Conclusions: Device-specific mechanical driveline features are an additional modifiable risk factor for DLI and may influence clinical outcomes of LVAD patients.

Access site complications of postcardiotomy extracorporeal life support

OBJECTIVE

To assess the influence of primary arterial access in patients receiving peripheral postcardiotomy extracorporeal life support on associated complications and outcome.

METHODS

Of 573 consecutive patients requiring PC-ECLS between 2000 and 2019 at a single center, 436 were included in a retrospective analysis and grouped according to primary arterial extracorporeal life support access site. Survival and rate of access-site-related complications with special emphasis on fatal/disabling stroke were compared.

RESULTS

The axillary artery was cannulated in 250 patients (57.3%), whereas the femoral artery was used as primary arterial access in 186 patients (42.6%). There was no significant difference in 30-day (axillary: 62%; femoral: 64.7%; P = .561) and 1-year survival (axillary: 42.5%; femoral: 44.8%; P = .657). Cerebral computed tomography-confirmed stroke with a modified ranking scale ≥4 was significantly more frequent in the axillary group (axillary: n = 28, 11.2%; femoral: n = 4, 2.2%; P = .0003). Stroke localization was right hemispheric (n = 20; 62.5%); left hemispheric (n = 5; 15.6%), bilateral (n = 5; 15.6%), or infratentorial (n = 2; 6.25%). Although no difference in major cannulation site bleeding was observed, cannulation site change for bleeding was more frequent in the axillary group (axillary: n = 13; 5.2%; femoral: n = 2; 1.1%; P = .03). Clinically apparent limb ischemia was significantly more frequent in the femoral group (axillary: n = 12, 4.8%; femoral: n = 31, 16.7%; P < .0001).

CONCLUSIONS

Although survival did not differ, surgeons should be aware of access-site-specific complications when choosing peripheral PC-ECLS access. Although lower rates of limb ischemia and the advantage of antegrade flow seem beneficial for axillary cannulation, the high incidence of right hemispheric strokes in axillary artery cannulation should be considered.

Relevance of Neutrophil Neprilysin in Heart Failure

Significant expression of neprilysin (NEP) is found on neutrophils, which present the transmembrane integer form of the enzyme. This study aimed to investigate the relationship of neutrophil transmembrane neprilysin (mNEP) with disease severity, adverse remodeling, and outcome in HFrEF. In total, 228 HFrEF, 30 HFpEF patients, and 43 controls were enrolled. Neutrophil mNEP was measured by flow-cytometry. NEP activity in plasma and blood cells was determined for a subset of HFrEF patients using mass-spectrometry. Heart failure (HF) was characterized by reduced neutrophil mNEP compared to controls (p < 0.01). NEP activity on peripheral blood cells was almost 4-fold higher compared to plasma NEP activity (p = 0.031) and correlated with neutrophil mNEP (p = 0.006). Lower neutrophil mNEP was associated with increasing disease severity and markers of adverse remodeling. Higher neutrophil mNEP was associated with reduced risk for mortality, total cardiovascular hospitalizations, and the composite endpoint of both (p < 0.01 for all). This is the first report describing a significant role of neutrophil mNEP in HFrEF. The biological relevance of neutrophil mNEP and exact effects of angiotensin-converting-enzyme inhibitors (ARNi) at the neutrophil site have to be determined. However, the results may suggest early initiation of ARNi already in less severe HF disease, where effects of NEP inhibition may be more pronounced.

Telocytes in the human ascending aorta: Characterization and exosome-related KLF-4/VEGF-A expression

Telocytes (TCs), a novel interstitial cell entity promoting tissue regeneration, have been described in various tissues. Their role in inter‐cellular signalling and tissue remodelling has been reported in almost all human tissues. This study hypothesizes that TC also contributes to tissue remodelling and regeneration of the human thoracic aorta (HTA). The understanding of tissue homeostasis and regenerative potential of the HTA is of high clinical interest as it plays a crucial role in pathogenesis from aortic dilatation to lethal dissection. Therefore, we obtained twenty‐five aortic specimens of heart donors during transplantation. The presence of TCs was detected in different layers of aortic tissue and characterized by immunofluorescence and transmission electron microscopy. Further, we cultivated and isolated TCs in highly differentiated form identified by positive staining for CD34 and c‐kit. Aortic‐derived TC was characterized by the expression of PDGFR‐α, PDGFR‐β, CD29/integrin β‐1 and αSMA and the stem cell markers Nanog and KLF‐4. Moreover, TC exosomes were isolated and characterized for soluble angiogenic factors by Western blot. CD34⁺/c‐kit⁺ TCs shed exosomes containing the soluble factors VEGF‐A, KLF‐4 and PDGF‐A. In summary, TC occurs in the aortic wall. Correspondingly, exosomes, derived from aortic TCs, contain vasculogenesis‐relevant proteins. Understanding the regulation of TC‐mediated aortic remodelling may be a crucial step towards designing strategies to promote aortic repair and prevent adverse remodelling.

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.

Mechanical circulatory support in pediatric patients with biventricular and univentricular hearts

Background

Mechanical circulatory support (MCS) in pediatric patients remains challenging because of small body size, limited availability of approved devices, and the variety of etiologies, including biventricular and univentricular physiologies. We report our single-center experience with MCS in pediatric patients in terms of survival and adverse events.

Methods

Outcome, etiologic, and demographic data of pediatric patients implanted with a long-term MCS device between 2011 and 2019 at the Medical University of Vienna were retrospectively collected and analyzed. Overall survival and freedom of treatment-related adverse events at 1 year were investigated by Kaplan–Meier analyses and stratified for circulation (biventricular vs univentricular), age group (<6 years vs >6 years), and pump technology (pulsatile ventricular assist device [p-VAD] vs continuous flow pump [cf-VAD]).

Results

One-year survival of all 33 pediatric patients (median, 4 years; interquartile range, 0-13 years) was 73%, with a tendency toward better outcomes in patients with biventricular circulation than in those with univentricular circulation (80%; n = 25 vs 50%; n = 8; P = .063). The trends toward better survival probability in older patients and in patients with cf-VADs did not reach statistical significance (63.2% vs 85.7%; P = .165 and 82.4% vs 62.5%; P = .179, respectively). Freedom from adverse events was higher in older patients (57.1% vs 5.6%; P < .001) and in the cf-VAD group (52.9% vs 0%; P < .001), with pump thrombosis as the main discriminator.

Conclusions

MCS is a promising therapy for a broad spectrum of pediatric patients, irrespective of heart failure etiology, age, and pump type. With increasing experience, improved devices, and patient selection, MCS may become a valuable treatment option for patients with univentricular hearts.

Reversal of pulmonary hypertension in paediatric patients with restrictive cardiomyopathy

Left ventricular assist devices can reverse pulmonary hypertension in cardiac transplant candidates with heart failure with a reduced ejection fraction. Whether a similar approach is applicable in restrictive cardiomyopathy is uncertain. We report the successful implantation of a Medtronic HVAD left ventricular assist device in a bridge-to-candidacy concept in 2 paediatric patients with restrictive cardiomyopathy.

Impact of extra-corporeal life support (ECLS) cannulation strategy on outcome after durable mechanical circulation support system implantation on behalf of durable MCS after ECLS Study Group

Background

The literature on outcomes of patients requiring durable mechanical circulatory support (MCS) after extra-corporeal life support (ECLS) is limited. The aim of this study was to investigate the impact of preoperative ECLS cannulation on postoperative outcome after durable MCS implantation.

Methods

The durable MCS after ECLS registry is a multicenter retrospective study that gathered data on consecutive patients who underwent durable MCS implantation after ECLS between January 2010 and August 2018 in eleven high volume European centers. Patients who underwent the implantation of total artificial heart, pulsatile pumps, or first-generation pumps after ECLS were excluded from the analysis. The remaining patients were divided into two groups; central ECLS group (cECLS) and peripheral ECLS group (pECLS). A 1:1 propensity score analysis was performed to identify two matched groups. The outcome of these two groups was compared.

Results

A total of 531 durable MCS after ECLS were implanted during this period. The ECLS cannulation site was peripheral in 87% (n=462) and central in 13% (n=69) of the patients. After excluding pulsatile pumps and total artificial heart patients, a total of 494 patients remained (pECLS =434 patients, cECLS =60 patients). A 1:1 propensity score analysis resulted in 2 matched groups (each 55 patients) with median age of 54 years (48-60 years) in cECLS group and 54 years (43-60 years) in pECLS group. HeartWare HVAD (Medtronic, Minneapolis, MN) was implanted in the majority of the patients (cECLS =71% vs. pECLS =76%, P=0.67). All postoperative morbidities were comparable between the groups. The thirty-day, one year and long-term survival was comparable between the groups (P=0.73).

Conclusions

The cannulation strategy of ECLS appears to have no impact on the post-operative outcome after durable MCS implantation.

Cardio-microcurrent device for chronic heart failure: first-in-human clinical study

AIMS

Most devices for treating ambulatory Class II and III heart failure are linked to electrical pulses. However, a steady electric potential gradient is also necessary for appropriate myocardial performance and may be disturbed by structural heart diseases. We investigated whether chronic application of electrical microcurrent to the heart is feasible and safe and improves cardiac performance. The results of this study should provide guidance for the design of a two-arm, randomized, controlled Phase II trial.

METHODS AND RESULTS

This single-arm, non-randomized pilot study involved 10 patients (9 men; mean age, 62 ± 12 years) at two sites with 6 month follow-up. All patients had New York Heart Association (NYHA) Class III heart failure and non-ischaemic dilated cardiomyopathy, with left ventricular ejection fraction (LVEF) <35%. A device was surgically placed to deliver a constant microcurrent to the heart. The following tests were performed at baseline, at hospital discharge, and at six time points during follow-up: determination of LVEF and left ventricular end-diastolic/end-systolic diameter by echocardiography; the 6 min walk test; and assessment of NYHA classification and quality of life (36-Item Short-Form Health Survey questionnaire). Microcurrent application was feasible and safe; no device-related or treatment-related adverse events occurred. During follow-up, rapid and significant signal of efficacy (P < 0.005) was present with improvements in LVEF, left ventricular end-diastolic diameter, left ventricular end-systolic diameter, and distance walked. For eight patients, NYHA classification improved from Class III to Class I (for seven, as early as 14 days post-operatively); for one, to Class II; and for one, to Class II/III. 36-Item Short-Form Health Survey questionnaire scores also improved highly significantly.

CONCLUSIONS

Chronic application of microcurrent to the heart is feasible and safe and leads to a rapid and lasting improvement in heart function and a near normalization of heart size within days. The NYHA classification and quality of life improve just as rapidly.

Transition From Temporary to Durable Circulatory Support Systems

BACKGROUND

The decision to implant durable mechanical circulatory systems (MCSs) in patients on extracorporeal life support (ECLS) is challenging due to expected poor outcomes in these patients.

OBJECTIVES

The aim of this study was to identify outcome predictors that may facilitate future patient selection and decision making.

METHODS

The Durable MCS after ECLS registry is a multicenter retrospective study that gathered data on consecutive patients who underwent MCS implantation after ECLS between January 2010 and August 2018 in 11 high-volume European centers. Several perioperative parameters were collected. The primary endpoint was survival at 1 year after durable MCS implantation.

RESULTS

A total of 531 durable MCSs after ECLS were implanted during this period. The average patient age was 53 ± 12 years old. ECLS cannulation was peripheral in 87% of patients and 33% of the patients had history of cardiopulmonary resuscitation before ECLS implantation. The 30-day, 1-year, and 3-year actuarial survival rates were 77%, 53%, and 43%, respectively. The following predictors for 1-year outcome have been observed: age, female sex, lactate value, Model of End-Stage Liver Disease XI score, history of atrial fibrillation, redo surgery, and body mass index >30 kg/m². On the basis of this data, a risk score and an app to estimate 1-year mortality was created.

CONCLUSIONS

The outcome in patients receiving durable MCS after ECLS remains limited, yet preoperative factors may allow differentiating futile patients from those with significant survival benefit.

Implanting the HeartMate 6 (total artificial heart)

The HeartMate 3 is a ventricular assist device that supports the heart with a centrifugal continuous flow. It contains a fully levitated rotor to minimize hemolysis and was initially designed as an apical intrapericardial implant. It can be used as a bridge to a transplant, to recovery, or to destination therapy. After we excise the ventricles, we implant 2 HeartMate 3 devices as a total artificial heart (HeartMate 6). The patient was 35 years old when the devices were implanted and had been diagnosed with Yamaguchi syndrome (apical hypertrophic cardiomyopathy) at 13 years of age. Being listed for a transplant was not an option due to secondary pulmonary hypertension. Furthermore, the conventional method of apically implanting a left ventricular assist device was not possible due to the underlying pathology. A HeartMate 6 implant as a bridge to transplant therapy was planned. Additionally, a CardioMEMS HF System was implanted to monitor the pulmonary artery pressure. The video tutorial provides step-by-step instructions for implanting 2 HeartMate 3 devices as a total artificial heart.

Concomitant cardiac surgery procedures during left ventricular assist device implantation: single-centre experience

Background

Additional cardiac pathologies including tricuspid or mitral valve regurgitation are common in left ventricular assist device (LVAD) recipients and whether to address them remains controversial. We present our institutional outcomes of concomitant cardiac procedures, other than temporary right ventricular (RV) support, at the time of LVAD implantation.

Methods

From 03/2006 to 06/2020, 352 adult patients {median age 60 [interquartile range (IQR): 52-66] years; INTERMACS level 1 29%; INTERMACS level 2 17%; INTERMACS level 3 23%, INTERMACS level 4-6 31%; male 86%} underwent continuous-flow LVAD [Medtronic HVAD^® (HVAD) 50%; Abbott HeartMate II^TM (HMII) 17%; Abbott HeartMate 3^TM (HM3) 33%] implantation. Concomitant valvular procedures were performed in 86 patients (24%) and the majority of patients received the LVAD as bridge to candidacy (BTC) for transplant (74%). Primary study endpoints were short- and mid-term mortality, as well as need for temporary RV support.

Results

Tricuspid valve annuloplasty was the most frequent concomitant procedure (77%), followed by aortic valve replacements (AVRs) or Park's stitch (33%). Temporary RV support was common in the study cohort (35%) using either extracorporeal life support (ECLS, 37%) or a temporary RV assist device (RVAD, 63%). A less invasive (LIS) implantation technique was pursued in 12%. Thirty-day mortality was comparable between those with and without concomitant surgery (4% vs. 6%, P=0.426). In-hospital mortality was significantly higher for additional interventions (22% vs. 14%, P=0.05), whereas one-year survival was similar (71% vs. 79%, P=0.106).

Conclusions

Concomitant cardiac procedures, especially tricuspid and aortic valve surgery, are frequent but are associated with a higher perioperative morbidity and mortality.

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.

Impact of a surgical approach for implantation of durable left ventricular assist devices in patients on extracorporeal life support

BACKGROUND

The aim of this study was to evaluate the impact of the surgical approach on the postoperative outcome in patients who underwent left ventricular assist device (LVAD) implantation after having received veno-arterial extracorporeal life support (va-ECLS) using data from a European registry (ECLS-VAD). Five hundred and thirty-one patients were included.

METHODS

A propensity score-adjusted outcome analysis was performed, resulting in 324 patients in the full sternotomy (FS) group and 39 in the less invasive surgery (LIS) group.

RESULTS

The surgery lasted in median 236 min in the FS group versus 263 min in the LIS group (p = 0.289). The median chest tube output during the first 24 h was similar in both groups. Patients who underwent implantation with an FS required more blood products during the first 24 postoperative hours (median 16 vs. 12, p = 0.033). The incidence of revision due to bleeding was also higher (35.5 vs. 15.4%, p = 0.016). A temporary postoperative right ventricular assist device was necessary in 45.1 (FS) versus 23.1% (LIS) of patients, respectively (p = 0.067). No stroke occurred in the LIS group during the first 30 days after surgery (7.4% in the FS group). The incidence of stroke and of renal, hepatic, and respiratory failure during the follow-up was similar in both groups. The 30-day and one-year survival were similar in both groups.

CONCLUSION

LIS for implantation of a durable LVAD in patients on va-ECLS implanted for cardiogenic shock is associated with less revision due to bleeding, less administration of blood products and absence of perioperative stroke, with no impact on survival.

Left ventricular assist device driveline infections in three contemporary devices

Driveline infections (DLI) are common adverse events in left ventricular assist devices (LVADs), leading to severe complications and readmissions. The study aims to characterize risk factors for DLI readmission 2 years postimplant. This single‐center study included 183 LVAD patients (43 HeartMate II [HMII], 29 HeartMate 3 [HM3], 111 HVAD) following hospital discharge between 2013 and 2017. Demographics, clinical parameters, and outcomes were retrospectively analyzed and 12.6% of patients were readmitted for DLI, 14.8% experienced DLI but were treated in the outpatient setting, and 72.7% had no DLI. Mean C‐reactive protein (CRP), leukocytes and fibrinogen were higher in patients with DLI readmission (P < .02) than in outpatient DLI and patients without DLI, as early as 60 days before readmission. Freedom from DLI readmission was comparable for HMII and HVAD (98% vs. 87%; HR, 4.52; 95% CI, 0.58‐35.02; P = .15) but significantly lower for HM3 (72%; HR, 10.82; 95% CI, 1.26‐92.68; P = .03). DLI (HR, 1.001; 95% CI, 0.999‐1.002; P = .16) or device type had no effect on mortality. DLI readmission remains a serious problem following LVAD implantation, where CRP, leukocytes, and fibrinogen might serve as risk factors already 60 days before. HM3 patients had a higher risk for DLI readmissions compared to HVAD or HMII, possibly because of device‐specific driveline differences.

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

OBJECTIVES

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

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 &lt; 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.

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.

Der Herzinsuffizienzchirurg – Hausarzt und Herzchirurg

Bei der Therapie der terminalen Herzinsuffizienz handelt es sich um einen Wachstumsmarkt – sowohl für Kardiologen als auch für Herzchirurgen. Der besondere Reiz der Arbeit eines Herzinsuffizienzchirurgen besteht in der notwendigen Multidisziplinarität und der Tatsache, dass es nicht nur um den rein mechanistischen Zugang im Sinne der chirurgischen Therapie geht. Vielmehr macht ein Großteil der Arbeit die Vor- und Nachbehandlung aus, die meist durch den Chirurgen selbst ausgeführt wird. Umfassende herzchirurgische Kenntnisse sind ebenso unumgänglich wie das Verständnis kardiologischer und intensivmedizinischer Therapiekonzepte, um dem Patienten eine individuelle und sinnvolle Therapie anbieten zu können. Der vorliegende Beitrag bietet interessierten Kollegen einen Überblick über die Möglichkeiten und Anforderungen in diesem Teilgebiet der Herzchirurgie.

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.

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.