Robert J. van Thiel

Connecting the Centrimag Levitronix pump to Berlin Heart Excor cannulae; a new approach to bridge to bridge.

BACKGROUND An increasing number of children are requiring circulatory support. Hospitals offering pediatric Ventricular Assist Device (VAD) should have devices of different sizes available to cover the full range of patient sizes incurring considerable expense. As in adults, post-operative bleeding often complicates VAD implantation. The use of a Levitronix Centrimag centrifugal pump, connected to Berlin Heart Excor cannulae, seems an attractive and logic combination, both in terms of patient safety and of hospital economics. METHODS We describe 3 children with therapy resistant cardiac failure who underwent extracorporeal membrane oxygenation (ECMO) as a rescue before proceeding to placement of the Berlin Heart Excor paracorporeal assist device. The Levitronix Centrimag pump was used as an intermediate device to allow the patients to be stabilised. Therefore, only Berlin Heart cannulae of different sizes have to be readily available; if successful stabilization can be achieved, the Berlin Heart Excor ventricles and the drive unit can then be ordered to replace the Levitronix pump. RESULTS Two patients were successfully stabilised with the Levitronix pump and were switched to the definitive Berlin Heart Excor ventricles after 6 days of support. The third child succumbed due to intractable pulmonary hemorrhage in severely damaged lungs. No device related complications, especially no thrombo-embolic events, occurred during Levitronix support. CONCLUSION The Levitronix Centrimag pump was easy to handle and gave effective circulatory support, the patients were only switched to the Berlin Heart Excor system after stabilization. In patients with a high risk of failure, it is a relatively cheap but safe and effective support system.

Mechanical circulatory support devices improve tissue perfusion in patients with end-stage heart failure or cardiogenic shock.

OBJECTIVES This study evaluated the effects of mechanical circulatory support (MCS) on sub-lingual microcirculation as a surrogate for splanchnic microvascular perfusion. METHODS Between May 2008 and April 2009, 10 consecutive patients received an MCS device or extracorporeal membrane oxygenation for end-stage chronic heart failure (n = 6) or cardiogenic shock (n = 4). Microcirculation was investigated using a hand-held Sidestream Dark Field imaging device. Perfused capillary density (PCD) and capillary red blood cell velocity (cRBCv) were assessed before device implantation (T0), immediately after implantation (T1), and 1 day after implantation (T2). RESULTS Median patient age was 45 years (interquartile range [IQR] 38-52 years) and 70% were men. MCS significantly decreased pulmonary capillary wedge pressure (p = 0.04). Median cardiac power index increased (0.29 [IQR, 0.21-0.34] W/m(2) at T0 vs 0.48 [IQR, 0.39-0.54] W/m(2) at T1, p = 0.005) as well as median central venous oxygen saturation (54% [IQR, 46%-61%] at T0 vs 78% [IQR, 67%-85%] at T1, p = 0.007). There was a 3-fold increase in tissue perfusion index (sub-lingual PCD x cRBCv) during mechanical circulatory support (573 [IQR, 407-693] at T0 vs 1909 [IQR, 1771-2835] at T1, p = 0.005). Microcirculatory parameters remained improved at T2. CONCLUSION Mechanical circulatory support for severe heart failure is associated with a consistent, significant, and sustained improvement in tissue perfusion, as measured at the bedside by a 2-dimensional microcirculation imaging technique.

Right Ventricular Unloading after Initiation of Venovenous Extracorporeal Membrane Oxygenation

Pulmonary hypertension frequently complicates acute respiratory distress syndrome (1), related to high airway pressures (2), hypoxia, and hypercapnia (3, 4). Venovenous extracorporeal membrane oxygenation (ECMO) improves oxygenation and reduces hypercapnia, facilitating lower airway pressures, and could thus decrease pulmonary hypertension and reduce right ventricular afterload. We therefore studied the effect of initiating venovenous ECMO on mean pulmonary artery pressure (mPAP), cardiac index (CI), and mixed venous oxygenation (Sv O2). Thirteen consecutive patients admitted to the Erasmus MC with acute respiratory failure treated with venovenous ECMO were included and studied for the first 6 hours after initiation. Before cannulation, a pulmonary artery catheter (777HF8; Edwards, Irvine, CA) was inserted. Heart rate, mean arterial pressures, peripheral oxygenation, mPAP, and CI were recorded just before initiation of venovenous ECMO (baseline) and at 30 seconds as well as 1, 3, 5, 10, and 15 minutes and 1 and 6 hours after initiation of venovenous ECMO. CI was measured continuously (Vigilance II monitor; Edwards). In six patients, Sv O2 measurements were available. All parameters were normally distributed. The effects of venovenous ECMO on hemodynamics and Sv O2 at each point were tested, using generalized estimating equations in all patients, at all points, with the baseline values as covariates. The association between mPAP and Sv O2 was tested with generalized estimating equations in six patients during the first 15 minutes. Values of the first blood gas after initiation of venovenous ECMO were subtracted from the values of the last blood gas analysis before venovenous ECMO and were defined as “D.” The associations among DPaO2, DPaCO2, and DmPAP were analyzed using Pearson’s correlation coefficient. All data are expressed in mean6 SE unless otherwise stated. Eleven men and two women (age, 586 3 yr) were included. All patients were diagnosed with pneumonia (seven bacterial, five viral, and one culture negative). Two patients were on the waiting list for lung transplantation. Baseline mPAP of these chronic patients was 26 and 43 mm Hg before initiation of venovenous ECMO. Three patients were treated with the Quadrox PLS oxygenator (Maquet, Rastatt, Germany); the others were treated with an iLa-Active system (6 XLung oxygenator and 4 NovaLung oxygenator; NovaLung, Heilbron, Germany). The NovaLung oxygenator does not have a heater, as the priming volume is low. In all other systems, ECMO blood flow was heated to 378C. One patient received a jugular 31-Fr double lumen cannula; all others received a 25or 29-Fr femoral cannula with a 19or 21-Fr reinfusion jugular cannula.

Improved long-term survival in Dutch heart transplant patients despite increasing donor age: the Rotterdam experience.

Over the past decades donor and recipient characteristics and medical management of heart transplantation (HT) patients have changed markedly. We studied the impact of these changes on long‐term clinical outcome. Data of all consecutive HT recipients in our center have been collected prospectively. Cohort A (n = 353) was defined as the adult pts transplanted between 1984 and 1999 and was compared with cohort B (n = 227) transplanted between 2000 and 2013. Compared with cohort A, recipients in cohort B had older donors (mean age 29 vs. 43 years, donors aged >50 year: 2% vs. 33%, respectively). Survival at 1 and 10 years in cohort A vs. B was 89% vs. 86% and 53% vs. 68%, respectively (P = 0.02). Cohort B pts were treated more often with tacrolimus‐based immunosuppression (77% vs. 22%; P = <0.0001) and early statins post‐HT (88% vs. 18%; P = 0.0001), while renal function was better conserved at 5 and 10 years (P = 0.001 and 0.02). Multivariate analysis showed significant reduction in 10‐year mortality with tacrolimus‐based immunosuppression (HR 0.27 and 95% CI 0.17–0.42), hypertension post‐HT (HR 0.5, 95% CI 0.36–0.72), and revascularization (HR 0.28, 95% CI 0.15–0.52). In spite of the use of much older donors, the long‐term outcome after HT has improved considerably in the last decade, probably due to the introduction of newer treatment modalities.

Dexamethasone for the prevention of postoperative atrial fibrillation

BACKGROUND Postoperative atrial fibrillation (AF) is a common complication after cardiac surgery. Inflammation is believed to play a pivotal role in the etiology of postoperative AF. There is a suggestion from small studies that perioperative treatment with corticosteroids may reduce postoperative AF. The DExamethasone for Cardiac Surgery (DECS) study was a large randomized trial showing no protective effect of dexamethasone on major adverse events. The aim of this study was to investigate the effect of dexamethasone treatment on the occurrence of AF after cardiac surgery. METHODS The DECS study compared intra-operative dexamethasone (1mg/kg) or placebo treatment in 4494 adult patients undergoing cardiac surgery. AF was defined by the occurrence of any reported AF within 30days after surgery. We also performed an in-depth analysis of a subset of 1565 patients on new-onset AF. Relative risks (RRs) with 95% confidence intervals (CIs) were calculated. RESULTS The incidence of any AF in the main study of 4494 patients was 33.1% in the dexamethasone and 35.2% in the placebo group (RR 0.94, 95% CI: 0.87-1.02, p=0.14). In the substudy of 1565 patients, the incidence of new-onset AF was 33.0% vs. 35.5% (RR 0.93, 95% CI: 0.81-1.07, p=0.31), respectively. There was no protective effect of dexamethasone across clinically important patient subgroups. CONCLUSION Intraoperative administration of dexamethasone had no protective effect on the occurrence of any or new-onset atrial fibrillation after cardiac surgery. Therefore, the use of dexamethasone for the reduction of postoperative AF should not be recommended.

Mobilization of patients on venovenous extracorporeal membrane oxygenation support using an ECMO helmet

Dear Editor, Venovenous extracorporeal membrane oxygenation (vvECMO) is increasingly used in patients with acute severe respiratory failure, when conventional treatment has failed. vvECMO can bridge patients to recovery or—in case of irreversible lung disease—to lung transplantation. Although ECMO patients are often considered to be not stable enough for active physical therapy, early reconditioning has been shown to improve outcome [1–4]. Since the development of a single bicaval duallumen cannula, patients can be mobilized during vvECMO. Theoretically, possible side effects of mobilization during ECMO therapy are severe hemodynamic or respiratory instability, even leading to collapse, and dislocation of the ECMO cannulas, which may lead to disturbance of the ECMO flow, decannulation, or bleeding. However, none of these events are actually reported [2–4]. To prevent cannula dislocation during mobilization, we first fixated the cannula manually. Next we tried an endotracheal tube holder to fixate the cannulas during mobilization. A cycling helmet fixated the cannula better, but a custom-made gypsum helmet (Fig. 1) achieved the best fixation while maintaining mobilization freedom. Between November 2012 and February 2014, six patients were mobilized with an ECMO helmet in our center (median age 52 years; four men). To make mobilization under ECMO support possible, the patients were awake and able to follow instructions. Furthermore, they were free of renal replacement therapy and had no high doses of vasopressors, which makes it a selected group of patients. With support of a physiotherapist, reconditioning was optimized for each patient, ranging from exercising in bed to walking outside the room. We defined the patient as ‘mobilized’ when he or she succeeded in at least sitting in bed in an upright position with both legs hanging outside of the bed. Reasons for respiratory failure of the patients were end-stage cystic fibrosis, idiopathic pleuroparenchymal fibroelastosis, idiopathic pulmonary fibrosis (n = 2), interstitial pulmonary disease after an influenza A pneumonia, and a complicated lung transplantation (pneumectomia of the transplanted lung) (see Table 1 for characteristics and outcomes). Four patients were able to stand and walk a short distance (up to 100 m) and two patients could sit upright with both legs hanging outside of the bed. Mobilization of all patients was uncomplicated. The ECMO cannulas did not need to be held by hand and did not dislocate in any patient during mobilization (measured by marks on the cannulas and skin). Eventually, four patients could be bridged to lung transplantation and two patients died on the ECMO. We concluded that mobilization of patients on vvECMO support with an ECMO helmet is feasible and safe.

Recovery of Long-Axis Left Ventricular Function after Aortic Valve Replacement in Patients with Severe Aortic Stenosis

Background: Patients with aortic stenosis (AS) should undergo aortic valve replacement (AVR) before irreversible LV dysfunction has developed. Assessment of long‐axis left ventricular (LV) function may assist in proper timing of AVR. Objectives: To assess serial changes in long‐axis LV function before and after AVR in patients with severe AS and preserved LV ejection fraction. Methods: The study comprised 27 consecutive patients (mean age 64.9 ± 11.7 years, 15 males) with symptomatic severe AS, scheduled for AVR. Seventeen subjects without known cardiac disease, matched for age, gender, LV ejection fraction and cardiovascular risk factors, served as a control group. Long‐axis LV function assessment was done with tissue Doppler imaging at 3 weeks, 6 months, and 12 months after AVR. Results: Mean aortic valve area in the AS group was 0.70 ± 0.24 cm2. Pre‐AVR peak systolic mitral annular velocities were significantly lower compared to controls (6.7 ± 1.5 vs. 8.9 ± 2.0 cm/s, P < 0.05). Post‐AVR peak systolic mitral annular velocities improved to 9.1 ± 2.9 at 3 weeks, 8.6 ± 2.7 at 6 months, and 8.1 ± 1.7 cm/s at 12 months (P < 0.05). Improvements were seen over the whole range of pre‐AVR peak systolic mitral annular velocities. Patients with improved Sm after AVR (defined as ≥10% compared to baseline values) did not differ in baseline characteristics as compared to those who did not improve. Conclusions: In patients with severe AS and preserved LV ejection fraction, abnormal systolic mitral annular velocities improve after AVR, independent of the pre‐AVR value. (Echocardiography 2010;27:1177‐1181)

Risk factors and prognosis of postpericardiotomy syndrome in patients undergoing valve surgery

Objective: The study aim was to investigate the long‐term prognosis and risk factors of postpericardiotomy syndrome (PPS). Methods: We performed a single‐center cohort study in 822 patients undergoing nonemergent valve surgery. Risk factors of PPS were evaluated using multivariable logistic regression analysis. We also compared the incidence of reoperation for tamponade at 1 year between patients with and without PPS. Main secondary outcomes were hospital stay and mortality. Results: Of the 822 patients, 119 (14.5%) developed PPS. A higher body mass index (odds ratio (OR) per point increase, 0.94; 95% confidence interval (CI), 0.89–0.99) was associated with a lower risk of PPS, whereas preoperative treatment for pulmonary disease without corticosteroids (OR, 2.55; 95% CI, 1.25–5.20) was associated with a higher risk of PPS. The incidence of reoperation for tamponade at 1 year in PPS versus no PPS was 20.9% versus 2.5% (OR, 15.49; 95% CI, 7.14–33.58). One‐year mortality in PPS versus no PPS was 4.2% versus 5.5% (OR, 0.68; 95% CI, 0.22–2.08). Median hospital stay was 13 days (interquartile range, 9–18 days) versus 11 days (interquartile range, 8–15 days) (P = .001), respectively. Conclusions: Despite longer hospital stays and more short‐term reoperations for tamponade, patients with PPS had an excellent 1‐year prognosis.

Functional evaluation of sublingual microcirculation indicates successful weaning from VA-ECMO in cardiogenic shock

BackgroundVeno-arterial extracorporeal membrane oxygenation (VA-ECMO) is increasingly adopted for the treatment of cardiogenic shock (CS). However, a marker of successful weaning remains largely unknown. Our hypothesis was that successful weaning is associated with sustained microcirculatory function during ECMO flow reduction. Therefore, we sought to test the usefulness of microcirculatory imaging in the same sublingual spot, using incident dark field (IDF) imaging in assessing successful weaning from VA-ECMO and compare IDF imaging with echocardiographic parameters.MethodsWeaning was performed by decreasing the VA-ECMO flow to 50% (F50) from the baseline. The endpoint of the study was successful VA-ECMO explantation within 48 hours after weaning. The response of sublingual microcirculation to a weaning attempt (WA) was evaluated. Microcirculation was measured in one sublingual area (single spot (ss)) using CytoCam IDF imaging during WA. Total vessel density (TVDss) and perfused vessel density (PVDss) of the sublingual area were evaluated before and during 50% flow reduction (TVDssF50, PVDssF50) after a WA and compared to conventional echocardiographic parameters as indicators of the success or failure of the WA.ResultsPatients (n = 13) aged 49 ± 18 years, who received VA-ECMO for the treatment of refractory CS due to pulmonary embolism (n = 5), post cardiotomy (n = 3), acute coronary syndrome (n = 2), myocarditis (n = 2) and drug intoxication (n = 1), were included. TVDssF50 (21.9 vs 12.9 mm/mm2, p = 0.001), PVDssF50 (19.7 vs 12.4 mm/mm2, p = 0.01) and aortic velocity–time integral (VTI) at 50% flow reduction (VTIF50) were higher in patients successfully weaned vs not successfully weaned. The area under the curve (AUC) was 0.99 vs 0.93 vs 0.85 for TVDssF50 (small vessels) >12.2 mm/mm2, left ventricular ejection fraction (LVEF) >15% and aortic VTI >11 cm. Likewise, the AUC was 0.91 vs 0.93 vs 0.85 for the PVDssF50 (all vessels) >14.8 mm/mm2, LVEF >15% and aortic VTI >11 cm.ConclusionThis study identified sublingual microcirculation as a novel potential marker for identifying successful weaning from VA-ECMO. Sustained values of TVDssF50 and PVDssF50 were found to be specific and sensitive indicators of successful weaning from VA-ECMO as compared to echocardiographic parameters.

Incidence, predictors and clinical outcome of early bleeding events in patients undergoing a left ventricular assist device implant

OBJECTIVES Bleeding is a common complication following left ventricular assist device (LVAD) implantation. The goal of this study was to investigate the incidence, predictors and clinical outcome of early bleeding events in patients after LVAD implantation. METHODS A total of 83 patients (age 50 ± 13 years, 76% men) had an LVAD implanted [77% HeartMate II, 19% HeartMate 3 (Abbott, Chicago, IL, USA)] over a period of 11 years. Patients were included consecutively. An early bleeding event was defined as the need for thoracic surgical re-exploration or transfusion with >4 units of packed red blood cells before discharge. RESULTS Overall, 39 (47%) patients (age 50 ± 14 years, 77% men) experienced an early bleeding event [median time 6 days (interquartile range 1-9 days)]. Furthermore, 10 (26%) of these patients had ≥2 bleeding events. Twelve of the 14 (92%) patients with venoarterial extracorporeal membrane oxygenation (ECMO) support before LVAD implantation experienced an early bleeding event versus 27 of the 69 (39%) patients without ECMO support (P < 0.001). No difference was found in early bleeding rates between HeartMate II and HeartMate 3. Predictors for early bleeding events were lower pre- and postimplant platelet counts and ECMO support preimplantation. After multivariable adjustment, early bleeding events were associated with ECMO support preimplantation (odds ratio 6.3, 95% confidence interval 1.2-32.4; P = 0.03) and thrombocytopenia (<150 × 109/l) postimplant (odds ratio 5.9, 95% confidence interval 1.9-18.7; P = 0.002). Patients who experienced an early bleeding event had a significantly worse 90-day survival rate compared to patients who did not (79% vs 96%, P = 0.03). CONCLUSIONS An early bleeding event needing surgical exploration is highly prevalent after LVAD implantation, especially in patients bridged with ECMO and with pre- and postimplant thrombocytopenia.