Features and Outcomes of Females and Males Requiring Postcardiotomy Extracorporeal Life Support

BACKGROUND

Although cardiogenic shock requiring extracorporeal life support (ECLS) after cardiac surgery is associated with high mortality, the impact of sex on outcomes of post-cardiotomy ECLS remains unclear with conflicting results in literature. We compare patient characteristics, in-hospital outcomes, and overall survival between females and males requiring post-cardiotomy ECLS.

METHODS

This retrospective, multicentre (34 centres), observational study included adults requiring post-cardiotomy ECLS between 2000 and 2020. Pre-operative, procedural, and ECLS characteristics, complications, and survival were compared between females and males. Association between sex and in-hospital survival was investigated through mixed-Cox proportional hazards models.

RESULTS

This analysis included 1823 patients [females:40.8%; median age:66.0 (interquartile range:56.2-73.0 years)]. Females underwent more mitral (females:38.4%, males:33.1%, p=0.019) and tricuspid (females:18%, males:12.4%, p<0.001) valve surgery, while males had more coronary artery surgery (females:45.9%, males:52.4%, p=0.007). ECLS implantation was more common intra-operatively in females (females:64.1%, males:59.1%) and post-operatively in males (females:35.9%, males:40.9%, p=0.036). Ventricular unloading (females:25.1%, males:36.2%, p<0.001) and intra-aortic balloon pump (females: 25.8%, males:36.8%, p<0.001) were most frequently used in males. Females suffered more post-operative right ventricular failure (females:24.1%, males:19.1%, p=0.016) and limb ischemia (females:12.3%, males:8.8%, p=0.23). In-hospital mortality was 64.9% in females and 61.9% in males (p=0.199) with no differences in 5-year survival (females:20%, 95%CI:17-23; males:24%, 95%CI:21-28;p=0.069). Crude hazard ratio for in-hospital mortality in females was 1.12 (95%CI: 0.99-1.27,p=0.069) and did not change after adjustments.

CONCLUSIONS

This study demonstrates that females and males requiring post-cardiotomy ECLS have different pre-operative and ECLS characteristics, as well as complications, without a statistical difference in in-hospital and 5-year survival.

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.

On-Support and Postweaning Mortality in Postcardiotomy Extracorporeal Membrane Oxygenation

BACKGROUND

Postcardiotomy venoarterial extracorporeal membrane oxygenation (VA ECMO) is characterized by discrepancies between weaning and survival-to-discharge rates. This study analyzes the differences between postcardiotomy VA ECMO patients who survived, died on ECMO, or died after ECMO weaning. Causes of death and variables associated with mortality at different time points are investigated.

METHODS

The retrospective, multicenter, observational Postcardiotomy Extracorporeal Life Support Study (PELS) includes adults requiring postcardiotomy VA ECMO between 2000 and 2020. Variables associated with on-ECMO mortality and postweaning mortality were modeled using mixed Cox proportional hazards, including random effects for center and year.

RESULTS

In 2058 patients (men, 59%; median age, 65 years; interquartile range [IQR], 55-72 years), weaning rate was 62.7%, and survival to discharge was 39.6%. Patients who died (n = 1244) included 754 on-ECMO deaths (36.6%; median support time, 79 hours; IQR, 24-192 hours), and 476 postweaning deaths (23.1%; median support time, 146 hours; IQR, 96-235.5 hours). Multiorgan (n = 431 of 1158 [37.2%]) and persistent heart failure (n = 423 of 1158 [36.5%]) were the main causes of death, followed by bleeding (n = 56 of 754 [7.4%]) for on-ECMO mortality and sepsis (n = 61 of 401 [15.4%]) for postweaning mortality. On-ECMO death was associated with emergency surgery, preoperative cardiac arrest, cardiogenic shock, right ventricular failure, cardiopulmonary bypass time, and ECMO implantation timing. Diabetes, postoperative bleeding, cardiac arrest, bowel ischemia, acute kidney injury, and septic shock were associated with postweaning mortality.

CONCLUSIONS

A discrepancy exists between weaning and discharge rate in postcardiotomy ECMO. Deaths occurred during ECMO support in 36.6% of patients, mostly associated with unstable preoperative hemodynamics. Another 23.1% of patients died after weaning in association with severe complications. This underscores the importance of postweaning care for postcardiotomy VA ECMO patients.

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.

Impacts of Telomeric Length, Chronic Hypoxia, Senescence, and Senescence-Associated Secretory Phenotype on the Development of Thoracic Aortic Aneurysm

Thoracic aortic aneurysm (TAA) is an age-related and life-threatening vascular disease. Telomere shortening is a predictor of age-related diseases, and its progression is associated with premature vascular disease. The aim of the present work was to investigate the impacts of chronic hypoxia and telomeric DNA damage on cellular homeostasis and vascular degeneration of TAA. We analyzed healthy and aortic aneurysm specimens (215 samples) for telomere length (TL), chronic DNA damage, and resulting changes in cellular homeostasis, focusing on senescence and apoptosis. Compared with healthy thoracic aorta (HTA), patients with tricuspid aortic valve (TAV) showed telomere shortening with increasing TAA size, in contrast to genetically predisposed bicuspid aortic valve (BAV). In addition, TL was associated with chronic hypoxia and telomeric DNA damage and with the induction of senescence-associated secretory phenotype (SASP). TAA-TAV specimens showed a significant difference in SASP-marker expression of IL-6, NF-κB, mTOR, and cell-cycle regulators (γH2AX, Rb, p53, p21), compared to HTA and TAA-BAV. Furthermore, we observed an increase in CD163⁺ macrophages and a correlation between hypoxic DNA damage and the number of aortic telocytes. We conclude that chronic hypoxia is associated with telomeric DNA damage and the induction of SASP in a diseased aortic wall, promising a new therapeutic target.

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.

Single Donor Infusion of S-Nitroso-Human-Serum-Albumin Attenuates Cardiac Isograft Fibrosis and Preserves Myocardial Micro-RNA-126-3p in a Murine Heterotopic Heart Transplant Model

Objectives: Cold ischemia and subsequent reperfusion injury are non-immunologic cornerstones in the development of graft injury after heart transplantation. The nitric oxide donor S-nitroso-human-serum-albumin (S-NO-HSA) is known to attenuate myocardial ischemia-reperfusion (I/R)-injury. We assessed whether donor preservation with S-NO-HSA affects isograft injury and myocardial expression of GATA2 as well as miR-126-3p, which are considered protective against vascular and endothelial injury.

Methods: Donor C57BL/6 mice received intravenous (0.1 μmol/kg/h) S-NO-HSA (n = 12), or 0.9% saline (control, n = 11) for 20 min. Donor hearts were stored in cold histidine-tryptophan-α-ketoglutarate-N solution for 12 h and underwent heterotopic, isogenic transplantation, except 5 hearts of each group, which were analysed immediately after preservation. Fibrosis was quantified and expression of GATA2 and miR-126-3p assessed by RT-qPCR after 60 days or immediately after preservation.

Results: Fibrosis was significantly reduced in the S-NO-HSA group (6.47% ± 1.76 vs. 11.52% ± 2.16; p = 0.0023; 12 h-S-NO-HSA-hHTX vs. 12 h-control-hHTX). Expression of miR-126-3p was downregulated in all hearts after ischemia compared to native myocardium, but the effect was significantly attenuated when donors received S-NO-HSA (1 ± 0.27 vs. 0.33 ± 0.31; p = 0.0187; 12 h-S-NO-HSA-hHTX vs. 12 h-control-hHTX; normalized expression to U6 snRNA).

Conclusion: Donor pre-treatment with S-NO-HSA lead to reduced fibrosis and preservation of myocardial miR-126-3p and GATA2 levels in murine cardiac isografts 60 days after transplantation.

A Sensorless Modular Multiobjective Control Algorithm for Left Ventricular Assist Devices: A Clinical Pilot Study

Background

Contemporary Left Ventricular Assist Devices (LVADs) mainly operate at a constant speed, only insufficiently adapting to changes in patient demand. Automatic physiological speed control promises tighter integration of the LVAD into patient physiology, increasing the level of support during activity and decreasing support when it is excessive.

Methods

A sensorless modular control algorithm was developed for a centrifugal LVAD (HVAD, Medtronic plc, MN, USA). It consists of a heart rate-, a pulsatility-, a suction reaction—and a supervisor module. These modules were embedded into a safe testing environment and investigated in a single-center, blinded, crossover, clinical pilot trial (clinicaltrials.gov, NCT04786236). Patients completed a protocol consisting of orthostatic changes, Valsalva maneuver and submaximal bicycle ergometry in constant speed and physiological control mode in randomized sequence. Endpoints for the study were reduction of suction burden, adequate pump speed and flowrate adaptations of the control algorithm for each protocol item and no necessity for intervention via the hardware safety systems.

Results

A total of six patients (median age 53.5, 100% male) completed 13 tests in the intermediate care unit or in an outpatient setting, without necessity for intervention during control mode operation. Physiological control reduced speed and flowrate during patient rest, in sitting by a median of −75 [Interquartile Range (IQR): −137, 65] rpm and in supine position by −130 [−150, 30] rpm, thereby reducing suction burden in scenarios prone to overpumping in most tests [0 [−10, 2] Suction events/minute] in orthostatic upwards transitions and by −2 [−6, 0] Suction events/min in Valsalva maneuver. During submaximal ergometry speed was increased by 86 [31, 193] rpm compared to constant speed for a median flow increase of 0.2 [0.1, 0.8] L/min. In 3 tests speed could not be increased above constant set speed due to recurring suction and in 3 tests speed could be increased by up to 500 rpm with a pump flowrate increase of up to 0.9 L/min.

Conclusion

In this pilot study, safety, short-term efficacy, and physiological responsiveness of a sensorless automated speed control system for a centrifugal LVAD was established. Long term studies are needed to show improved clinical outcomes.

Clinical Trial Registration

ClinicalTrials.gov, identifier: NCT04786236.

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.

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.

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.

Decrease in serum alkaline phosphatase and prognostic relevance in adult cardiopulmonary bypass

OBJECTIVES

Cardiopulmonary bypass (CPB) induces inflammatory responses, which may lead to the loss of alkaline phosphatase (AP) that is consumed in the process of dephosphorylating detrimental extracellular nucleotides in this proinflammatory state. It has been reported that low postoperative AP levels correlate with increased postoperative support requirement and organ dysfunction after paediatric cardiac surgery. However, little is known about the perioperative development and clinical relevance of AP depletion in adults undergoing CPB.

METHODS

A total of 183 patients with a preoperative left ventricular ejection fraction ≤50% undergoing mitral valve surgery ± concomitant related procedures at the Department of Cardiac Surgery, Medical University of Vienna, between 2013 and 2016 were included in this retrospective analysis. Serum AP measurements at baseline and on postoperative days 1-15 were collected. Absolute and relative drop of AP on postoperative day 1 from baseline was correlated with perioperative and early postoperative parameters. Receiver operating characteristics were used to define suitable predictors and cut-offs for postoperative outcome variables.

RESULTS

Receiver operating characteristics showed a reduction of >50% of baseline AP to predict in-hospital mortality [area under the curve (AUC) 0.807], prolonged intensive care unit stay (>72 h, AUC 0.707), prolonged mechanical ventilation (>24 h, AUC 0.712) and surgery-related dialysis requirement (AUC 0.736). Patients with a perioperative reduction in circulating AP to levels below 50% of baseline had a significantly decreased survival. Patients with high perioperative AP loss had higher preoperative AP levels (P < 0.001), longer CPB duration (P < 0.001) and higher incidence of extracorporeal membrane oxygenation support (P < 0.001).

CONCLUSIONS

Increased perioperative AP loss is associated with adverse early outcome. Prospective trials are needed to determine whether this effect can be counteracted by perioperative AP supplementation.

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.

Molecular-level HLA mismatch is associated with rejection and worsened graft survival in heart transplant recipients - a retrospective study

The aim was to evaluate the association of molecular‐level human leukocyte antigen (HLA) mismatching with post‐transplant graft survival, rejection, and cardiac allograft vasculopathy (CAV). We retrospectively analyzed all primary cardiac transplant recipients between 01/1984‐06/2016. 1167 patients fulfilled inclusion criteria and had HLA typing information available. In 312 donor‐recipient pairs, typing at serological split antigen level was available. We used the Epitope MisMatch Algorithm to calculate the number of amino acid differences in antibody‐verified HLA eplets (amino acid mismatch load (AAMM)) between donor and recipient. Patients with a higher HLA‐DR AAMM load had inferior 1‐year graft survival (hazard ratio [HR], 1.14; 95% confidence interval [CI], 1.01–1.28). The HLA‐AB AAMM load showed no impact on graft survival. In the subgroup with available split‐level information, we observed an inferior graft survival for a higher HLA‐DR AAMM load 3 months after transplantation (HR, 1.22; 95% CI, 1.04–1.44) and a higher risk for rejection for an increasing HLA‐AB (HR, 1.70; 95% CI, 1.29–2.24) and HLA‐DR (HR, 1.32; 95% CI, 1.09–1.61) AAMM load. No impact on the development of CAV was found. Molecular‐level HLA mismatch analysis could serve as a tool for risk stratification after heart transplantation and might take us one step further into precision medicine.

Anticoagulation strategy in a patient on the HeartMate III® left ventricular assist device with acquired von Willebrand syndrome and recurring gastrointestinal bleeding episodes: sometimes less is more

Acquired von Willebrand syndrome is a frequently encountered complication of continuous flow ventricular assist devices, which may lead to clinically relevant bleeding in up to 30% of patients after continuous flow ventricular assist device implantation. As standard anticoagulation strategies may be detrimental, individualized treatment is called for, as described in our patient on the HeartMate III® left ventricular assist device.

Extracorporeal immunoadsorption in heparin- and protamine-induced thrombocytopaenia prior to cardiac surgery

Exposure to heparin and protamine during cardiac surgery on cardiopulmonary bypass (CPB) may trigger heparin-induced thrombocytopaenia and/or protamine-induced thrombocytopaenia. Further surgery on CPB with heparin and protamine in the presence of these antibodies implies increased thromboembolic risk. We present the successful application of extracorporeal immunoadsorption to deplete antibodies causing heparin-induced and protamine-induced thrombocytopaenia preoperatively.

Heparin-induced thrombocytopaenia diagnostic testing after adult cardiac surgery: a single-centre experience and development

OBJECTIVES

To assess the incidence and outcome of heparin-induced thrombocytopaenia (HIT) in patients after cardiac surgery on cardiopulmonary bypass (CPB) and to review the time course of platelet counts and the use of different immunological diagnostic tests.

METHODS

All patients ≥18 years of age who underwent CPB from 2006 to 2015 and who were postoperatively admitted to our cardiac intensive care unit (ICU) were included in this retrospective study. Screening for heparin/platelet factor-4 antibodies was performed using an antibody test, which was later replaced with a screening test specific for IgG antibodies without IgA/IgM cross-reactivity. The enzyme immunoassay (EIA) for the detection of antibodies of all immunoglobulin classes against heparin/PF4 complexes was replaced with an IgG-specific EIA. HIT was confirmed by a heparin-induced platelet aggregation test until 2014.

RESULTS

Among 4978 patients admitted between 2006 and 2015, 539 (11%) patients were evaluated for HIT. Patients were excluded because of age <18 years (n = 9), non-cardiac surgery without CPB (n = 10) or incomplete data (n = 3). Of the remaining 517 patients, 43 (8.3%) patients were HIT-positive. HIT incidence was 0.86%. The proportion of HIT-positive patients was similar in men and women (8.4% and 8.2%, respectively). Men and women with suspected HIT also had similar in-hospital mortality (odds ratio ≈ 1; P = 0.926).

CONCLUSIONS

The incidence of HIT was lower in our study than previously reported. Novel immunological tests have improved to specifically detect IgG antibodies. Furthermore, they are able to detect anti-protamine antibodies, which may be present in patients with high clinical probability of testing negative for HIT. Incidence and clinical relevance of heparin/protamine antibodies will be subjects of future investigation.

The impact of age on cardiac function and extracellular matrix component expression in adverse post-infarction remodeling in mice

The aim of this study was to describe the potential associations of the expression of matricellular components in adverse post-infarction remodeling of the geriatric heart. In male geriatric (OM, age: 18 months) and young (YM, age: 11 weeks) OF1 mice myocardial infarction (MI) was induced by permanent ligation of the left anterior descending coronary artery. Cardiac function was evaluated by MRI. Plasma and myocardial tissue samples were collected 3d, 7d, and 32d post-MI. Age and MI were associated with impaired cardiac function accompanied by left-ventricular (LV) dilatation. mRNA expression of MMP-2 (7d: p < 0.05), TIMP-1 (7d: p < 0.05), TIMP-2 (7d: p < 0.05), Collagen-1 (3d and 7d: p < 0.05) and Collagen-3 (7d: p < 0.05) in LV non-infarcted myocardium was significantly higher in YM than in OM after MI. MMP-9 activity in plasma was increased in OM after MI (3d: p < 0.01). Tenascin-C protein levels assessed by ELISA were decreased in OM as compared to YM after MI in plasma (3d: p < 0.001, 7d: p < 0.05) and LV non-infarcted myocardium (7d: p < 0.01). Dysregulation in ECM components in non-infarcted LV might be associated and contribute to adverse LV remodeling and impaired cardiac function. Thus, targeting ECM might be a potential therapeutic approach to enhance cardiac function in geriatric patients following MI.

Cusp Tear of Trifecta™ Aortic Bioprosthesis Resulting in Acute Heart Failure

Herein is presented the case of an 83-year-old male patient in cardiogenic shock with acute aortic regurgitation that occurred six years after aortic valve replacement (AVR) with a 23 mm Trifecta™ valve. Prosthesis endocarditis was initially suspected because of a floating structure attached to the aortic valve that was visible on echocardiography. Emergency redo-AVR surgery was performed, but no signs of endocarditis were found intraoperatively. Hence, cusp tearing of the implanted bioprosthesis was considered to be the reason for the severe aortic regurgitation.