Prediction of right ventricular failure after left ventricular assist device implantation in patients with heart failure: a meta-analysis comparing echocardiographic parameters

 Open in a separate windowOBJECTIVESBetween 10% and 40% of patients who receive a left ventricular assistance device (LVAD) suffer from right ventricular failure (RVF) shortly after the device is implanted. Patients with post-LVAD RVF tend to have poor outcomes. Only a few predictive factors concerning the right ventricle (RV) have been investigated. Our goal was to search for non-invasive variables that correlate with RV function, focusing on echocardiographic parameters of the RV. METHODSWe selected 3 parameters: tricuspid annular plane systolic excursion, right ventricular fractional area change and right ventricular global longitudinal strain. We searched the literature and pooled relevant studies in a meta-analysis. Finally, we performed a statistical analysis to confirm whether each parameter was a reliable predictor of RVF after LVAD implantation.RESULTSWe retained 19 articles involving a total of 1561 patients. We found a pooled standardized mean deviation of −0.13 cm for the tricuspid annular plane systolic excursion, with the lower and upper tails of −0.21 and −0.04 cm, respectively. Concerning the right ventricular fractional area change, the averaged standardized mean deviation was equal to −2.61%, with the lower and upper extremities of −4.12% and −1.09%, respectively. Finally, regarding the global longitudinal strain, the standardized mean deviation was equal to −2.06% with an uncertainty value between −3.23% and −0.88%.CONCLUSIONSThe tricuspid annular plane systolic excursion could be a reliable parameter in RVF prediction. The right ventricular fractional area change and global longitudinal strain are likely to be stronger predictors of RVF after LVAD implantation. Prospective studies should be carried out to confirm this observation.     

Left ventricular assist device implants in patients on extracorporeal membrane oxygenation: do we need cardiopulmonary bypass?

Open in a separate window OBJECTIVESImplanting a durable left ventricular assist device (LVAD) in a patient on extracorporeal life support (ECLS) is challenging. The goal of this study was to compare the results of patients from a European registry who had a durable LVAD implanted with or without transition from ECLS to cardiopulmonary bypass (CPB).METHODSA total of 531 patients on ECLS support who had an LVAD implant between January 2010 and August 2018 were analysed; after 1:1 propensity score matching, we identified and compared 175 patients in each group.RESULTSThe duration of preoperative ECLS was 7 [standard deviation (SD) 6] vs 7 (SD 6) days in patients with or without CPB (P = 0.984). The surgical time was longer in the CPB group [285 (SD 72) vs 209 [SD 75] min; P ≤ 0.001). The postoperative chest tube output was comparable [1513 (SD 1311) vs 1390 (SD 1121) ml; P = 0.3]. However, re-exploration for bleeding was necessary in 41% vs 29% of patients with or without CPB (P = 0.01) and a significantly higher number of packed red blood cells and fresh frozen plasma [8 (SD 8) vs 6 (SD 4) units; P = 0.001 and 6 (SD 7) vs 5 (SD 5) units; P = 0.03] were administered to patients operated on with CPB. A postoperative mechanical right ventricular support device was necessary in 50% vs 41% of patients (P = 0.08). The stroke rate was not significantly different (P 0.99). No difference in survival was observed.CONCLUSIONSOmitting CPB for an LVAD implant in patients on ECLS is safe and results in shorter operating time, less re-exploration for bleeding and fewer blood products. However, no survival benefit is observed.     

Results from a multicentre evaluation of plug use for left ventricular assist device explantation

Open in a separate window OBJECTIVESMyocardial recovery allows for left ventricular assist device (LVAD) explantations after long-term support. Several surgical approaches, including interventional decommissioning, off-pump explantation using a custom-made plug and complete LVAD removal through redo sternotomy, have been described. We present the results from an evaluation of the long-term follow-up of patients who received a titanium sintered plug after LVAD explantation. METHODSWe performed a retrospective, European, multicentre analysis of patients who received a titanium sintered plug to seal the apical fixation ring after LVAD explantation. Data were collected from a questionnaire that included demographics, procedural details and follow-up information.RESULTSOut of 54 contacted centres in 12 countries (n = 179 patients), a total of 68 patients were successfully included in the study. The median follow-up was 34 months (interquartile range: 17–58.5 months); 57 (84%) patients had >1-year follow-up. At the time of the last follow-up, 55 (81%) patients were alive, with a Kaplan–Meier 1-year survival of 90.1% (95% confidence interval: 84.0–98.1%) and a 5-year survival of 80.0% (95% confidence interval: 68.4–92.9%). One patient (1.5%) developed a plug infection originating from an infected part of the incorporated driveline and, after complete removal, is currently in good condition. No postoperative stroke has been reported after plug implantation.CONCLUSIONSIn this European multicentre study, the use of a custom-made titanium plug to close the apical fixation ring after LVAD explantation resulted in a low incidence of plug-related complications. With the volume of patients undergoing LVAD explantations after myocardial recovery increasing, the plug has evolved as a simple alternative to more invasive device explantation procedures or decommissioning with a high risk for infection of the remaining system or stroke.     

Mid-term outcomes of Contegra implantation for the reconstruction of the right ventricular outflow tract to proximal branch pulmonary arteries: Japan multicentre study

Open in a separate window OBJECTIVESTo reveal the mid-term outcomes of Contegra implantation for the reconstruction of the right ventricular outflow tract to proximal branch pulmonary arteries in a multicentre study. METHODSBetween April 2013 and December 2019, 178 Contegra conduits were implanted at 5 Japanese institutes. The median age and body weight at operation were 16 months (25th–75th percentile: 8–32) and 8.3 kg (6.4–10.6). Sixteen patients were neonates (9.0%). Selected conduit sizes were 12 mm in 28 patients (15.7%), 14 mm in 67 patients (37.6%), 16 mm in 66 patients (37.1%), 18 mm in 5 patients (2.8%) and <12 mm in 12 patients (6.7%). Fifty-six grafts (31.4%) were ring supported. Proximal branch pulmonary arteries were concomitantly augmented in 85 patients (47.5%). Follow-up was completed in all patients and the median follow-up period was 3.1 years (1.3–5.1).RESULTSThe overall, conduit explantation-free and conduit infection-free survival rates at 5 years were 91.3%, 71.0% and 83.7%, respectively. Infection (P = 0.009) and common arterial trunk (P = 0.024) were risk factors for explantation. Conduit durability was shorter in smaller one (P < 0.001). Catheter interventions (for conduit to proximal branch pulmonary artery)-free survival rates at 5 years was 52.9%; however, need for catheter interventions was not a risk factor for conduit explantation.CONCLUSIONSMid-term outcomes of reconstruction of the right ventricular outflow tract to the proximal branch pulmonary arteries with Contegra were acceptable. The need for explantation over time was higher in smaller conduits. Conduit infection was a strong risk factor for conduit explantation. Frequently and repeated catheter interventions effectively extended the conduit durability.     

Impact of reductive tricuspid ring annuloplasty on right ventricular size,geometry and strain in an ovine model of functional tricuspid regurgitation

Open in a separate window OBJECTIVESReductive ring annuloplasty of the tricuspid annulus represents the contemporary surgical approach to functional tricuspid regurgitation (FTR). We set out to investigate the influence of moderate reductive tricuspid ring annuloplasty on tricuspid regurgitation and right ventricular (RV) size, geometry and strain in an ovine model of chronic FTR.METHODSEight healthy Dorsett male sheep (62.8 + 2kg) underwent a left thoracotomy for placement and tightening of pulmonary artery band to at least double proximal pulmonary artery blood pressure. After 8 weeks of recovery, animals underwent sternotomy, epicardial echocardiography and sonomicrometry crystal implantation. Six crystals were placed around tricuspid annulus and 13 on RV free wall epicardium along 3 parallels defining 3 wall regions (basal, mid and lower) and 1 on the RV apex. All animals underwent beating heart implantation of 26 mm MC3 annuloplasty ring during a second cardiopulmonary bypass run after baseline data acquisition. Simultaneous haemodynamic, sonomicrometry and echocardiography data were acquired at Baseline and after reductive tricuspid ring annuloplasty.RESULTSImplantation of reductive ring annuloplasty resulted in 47 ± 7% annular area reduction (996 ± 152 mm vs 516 ± 52 mm², P = 0.0002) and significantly decreased RV end-diastolic volume (185 ± 27 vs 165 ± 30 ml, P = 0.02). Tricuspid ring annuloplasty effectively reduced FTR grade (3.75 ± 0.6 vs 0.3 ± 0.5, P = 0.00004) and had little influence on RV function, cross-sectional area, radius of curvature or free wall regional strains.CONCLUSIONSIn adult sheep with 8 weeks of pulmonary artery banding and FTR, tricuspid annulus reduction of 47% with prosthetic ring annuloplasty effectively abolished FTR while maintaining regional RV function and strain patterns.     

A detailed explantation assessment protocol for patients with left ventricular assist devices with myocardial recovery

Open in a separate window OBJECTIVESLeft ventricular assist device (LVAD) implantation for end-stage heart failure patients has been on the rise, providing a reliable long-term option. For some LVAD patients, longer term LV unloading leads to recovery; hence, the need for evaluating potential myocardial recovery and weaning eligibility has emerged.METHODSAll patients who underwent contemporary LVAD explantation at our institution between 2009 and 2020 were included in the study. Patients in New York Heart Association I, left ventricular ejection fraction >40%, a cardiac index >2.4 l/min and a peak oxygen intake >50% predicted underwent a 4-phase weaning assessment. A minimally invasive approach using a titanium plug was the surgery of choice in the most recent explants. Kaplan–Meier curves were used to estimate the survival at 1 and 5 years.RESULTSTwenty-six patients (17 HeartMate II, 9 HeartWare) underwent LVAD explantation after a median 317 days of support [IQ (212–518)], range 131–1437. Mean age at explant was 35.8 ± 12.7 years and 85% were males. Idiopathic dilated cardiomyopathy was the underlying diagnosis in 70% of cases. Thirteen (48%) patients were on short-term mechanical circulatory support and 60% required intensive care unit admission prior to the LVAD implantation. At 1 year, Kaplan–Meier estimated survival was 88%, whereas at 6 years, it was 77%. The average left ventricular ejection fraction at 1 year post-explant was 44.25% ± 8.44.CONCLUSIONSThe use of a standardized weaning protocol (echocardiographic and invasive) and a minimally invasive LVAD explant technique minimizes periprocedural complications and leads to good long-term device-free survival rates.     

Impact of cardiac fibrosis and collagens on right ventricular failure and acute kidney injury in patients after continuous-flow left ventricular assist devices

 Open in a separate windowOBJECTIVESWe aim to investigate the impact of cardiac fibrosis and collagens on right ventricular failure (RVF) and acute kidney injury (AKI) in patients receiving continuous flow left ventricular assist devices.METHODSHeart tissues from 34 patients were obtained from continuous flow left ventricular assist device insertion sites and corresponding clinical data were collected. The participants were divided into 2 groups according to the extent of the cardiac fibrosis or collagens.RESULTSOverall, 18 patients developed RVF with 14 receiving right ventricular assist device (RVAD), and 22 patients developed AKI with 12 needing new-onset renal replacement therapy. Higher collagen I (Col1) was significantly associated with increased incidences of RVF (76.5% vs 29.4%, P = 0.015), RVAD support (64.7% vs 17.6%, P = 0.013) and stage 3 AKI (58.8% vs 17.6%, P = 0.032), and patients with higher Col1 were more prone to renal replacement therapy (52.9% vs 17.6%, P = 0.071). Receiver operating characteristic curves showed that Col1 had good predictive effects on RVF [area under the curve (AUC) = 0.806, P = 0.002], RVAD support (AUC = 0.789, P = 0.005), stage 3 AKI (AUC = 0.740, P = 0.020) and renal replacement therapy (AUC = 0.731, P = 0.028) after continuous-flow left ventricular assist device. Moreover, patients with higher Col1 had significantly longer postoperative duration of mechanical ventilation, duration of intensive care unit stay and hospital length of stay (all P < 0.05). Cardiac fibrosis, collagen III (Col3) and Col1/Col3 shared similar results or trends with Col1.CONCLUSIONSCardiac fibrosis and related collagens in the apical left ventricular tissue are associated with increased risks of RVF, RVAD use and worse renal function. Further study is warranted owing to the small sample size.     

The influence of preoperative dialysis on survival after continuous-flow left ventricular assist device implantation

 Open in a separate windowOBJECTIVESDialysis is considered a contraindication to continuous-flow left ventricular assist device (CF-LVAD) implantation. We evaluated clinical outcomes and survival in carefully selected, low-risk patients with renal failure who required dialysis before CF-LVAD implantation.METHODSWe extracted medical record data of patients who underwent CF-LVAD placement at our centre between 1 January 2006 and 31 August 2017, with 2 clinical scenarios: those who required long-term (>14 days) dialysis and those who required short-term (≤14 days) dialysis immediately before implantation. Demographic, clinical and intraoperative characteristics and survival outcomes were assessed.RESULTSOf 621 patients who underwent CF-LVAD implantation during the study period, 31 underwent dialysis beforehand. Of these, 17 required long-term dialysis (13 haemodialysis, 4 peritoneal dialysis), and 14 underwent short-term haemodialysis. Compared with the long-term dialysis patients, the short-term dialysis patients were more likely to be Interagency Registry for Mechanically Assisted Circulatory Support profile 1–2 (92.9% vs 70.6%; P < 0.001), to have needed preoperative mechanical circulatory support (78.6% vs 70.6%; P < 0.01) and to have higher in-hospital mortality (85.7% vs 29.4%; P = 0.01). Patients stable on long-term dialysis had acceptable overall survival and markedly better 6-month and 1-year survival than those with short-term dialysis before implantation (64.7% vs 14.3% and 58.8% vs 7.1%, respectively; P < 0.001).CONCLUSIONSCarefully selected patients who are stable on long-term dialysis have acceptable survival rates after CF-LVAD implantation. Patients with acute renal failure had much poorer outcomes than those with chronic end-stage renal disease.     

Survival after left ventricular assist device implantation correlates with a novel device-based measure of heart rate variability: the heart rate score

Open in a separate window OBJECTIVESThe heart rate score (HRS) serves as a device-based measure of impaired heart rate variability and is an independent predictor of death in patients with heart failure and a cardiac implantable electrical device. However, no data are available for predicting death from the HRS in patients with end stage heart failure and a left ventricular assist device.METHODSFrom November 2011 to July 2018, a total of 56 patients with a pre-existing cardiac implantable electrical device underwent left ventricular assist device implantation at our 2 study sites. The ventricular HRS was calculated retrospectively during the first cardiac implantable electrical device follow-up examination following the index hospitalization. Survival during follow-up was correlated with initial HRS.RESULTSDuring the follow-up period, 46.4% of the patients (n = 26) died. The median follow-up period was 33.2 months. The median HRS after the index hospitalization was 41.1 ± 21.8%. More patients with an HRS >65% died compared to patients with an HRS <30% (76.9% vs 14.4%; P = 0.007).CONCLUSIONSIn our multicentre experience, survival of patients after an left ventricular assist device implant correlates with the HRS. After confirmation of our findings in a larger cohort, the effect of rate-responsive pacing will be within the scope of further investigation.     

Does microbiological contamination of homografts prior to decontamination affect the outcome after right ventricular outflow tract reconstruction?

Open in a separate window OBJECTIVESHomografts are often in short supply. Today, European guidelines recommend that all tissues contaminated by any of 18 different bacteria and fungi be discarded before antibiotic decontamination has been conducted. The tissue bank in Lund uses more liberal protocols: It accepts all microbes prior to decontamination except multiresistant microbes and Pseudomonas species. The aim of this study was to analyse the effect of contamination on the long-term outcome and occurrence of endocarditis in recipients.METHODSData were collected on homografts and on recipients of homografts in the right ventricular (RV) outflow tract who were operated on between 1995 and 2018 in Lund. The long-term outcome of recipients was analysed in relation to different types of contamination using Cox proportional hazard regression. The proportion of patients with endocarditis was analysed with the χ² test.RESULTSThe study included 509 implanted homografts. Follow-up was a maximum of 24 years and 99% complete. A total of 156 (31%) homografts were contaminated prior to antibiotic decontamination. Homografts contaminated with low-risk microbes had the lowest reintervention rate, but there was no significant difference compared to no contamination [hazard ratio (HR) 1.1, 95% confidence interval (CI) 0.73–1.7] or contamination with high-risk microbes (HR 1.6, 95% CI 0.87–2.8) in the multivariable analysis. There was no significant difference in the proportion of cases of endocarditis during the follow-up period between recipients of homografts contaminated prior to decontamination and recipients of homografts with no contamination (P = 0.83).CONCLUSIONSContamination of homograft tissue prior to decontamination did not show any significant effect on the long-term outcome or the occurrence of endocarditis after implantation in the RV outflow tract. Most contaminated homografts can be used safely after approved decontamination.     

Impact of pretransplant left ventricular assist device support duration on outcome after heart transplantation

 Open in a separate windowOBJECTIVESHeart transplantation after left ventricular assist device (LVAD) implantation remains challenging. It is still unclear whether its support duration impacts the outcome after transplantation. METHODSAll patients undergoing heart transplantation between 2010 and 2021 at a single department after previous left ventricular assistance were retrospectively reviewed and divided into 4 different study groups with regard to the duration of LVAD support to examine the impact on the postoperative morbidity and mortality.RESULTSA total of n = 198 patients were included and assigned to the 4 study groups (group 1: <90 days, n = 14; group 2: 90 days to 1 year, n = 31; group 3: 1–2 years, n = 29; group 4: >2 years, n = 24). Although there were no differences between the 4 groups concerning relevant mismatch between the recipients and donors, the incidence of primary graft dysfunction was numerically increased in patients with the shortest support duration, and also those patients with >1 year of support (group 1: 35.7%, group 2: 25.8%, group 3: 41.4%, group 4: 37.5%, P = 0.63). The incidence of acute graft rejection was by trend increased in patients of group 1 (group 1: 28.6%, group 2: 3.3%, group 3: 7.1%, group 4: 12.5%, P = 0.06). Duration of LVAD support did not impact on perioperative adverse events (infections, P = 0.79; acute kidney injury, P = 0.85; neurological events, P = 0.74; thoracic bleeding, P = 0.61), neither on postoperative survival (1-year survival: group 1: 78.6%, group 2: 66.7%, group 3: 80.0%, group 4: 72.7%, P = 0.74).CONCLUSIONWe cannot identify a significant impact of the duration of pretransplant LVAD support on postoperative outcome; therefore, we cannot recommend a certain timeframe for transplantation of LVAD patients.     

Mid-term outcomes of coronary artery bypass grafting in patients with mild left ventricular systolic dysfunction: a multicentre retrospective cohort study

 Open in a separate windowOBJECTIVESLeft ventricular systolic dysfunction (LVSD) is common and associated with adverse events in patients receiving coronary artery bypass grafting (CABG). However, the prognosis of mild LVSD has not been clearly described. We aimed to evaluate the mid-term outcomes of patients with mild LVSD following CABG.METHODSThis multicentre cohort study using propensity score matching took place from December 2012 to October 2019 in Jiangsu Province, China, with a mean and maximum follow-up of 3.2 and 7.2 years, respectively. Patients were classified to normal left ventricular systolic function (left ventricular ejection fraction ≥53%) and mild LVSD (left ventricular ejection fraction >40%/<53%). The primary outcomes were death from all causes and death from cardiovascular causes. The secondary outcomes were heart failure, myocardial infarction, repeat revascularization and a composite of all mentioned outcomes, including death from all causes (major adverse events).RESULTSA total of 581 pairs were formed after matching. In-hospital death (1.5% vs 2.1%, P = 0.51) did not differ between 2 cohorts. Throughout 7 years, mild LVSD was associated with higher rates of death from all causes [hazard ratio (HR) 0.59, 95% confidence interval (CI) 0.39–0.89; P = 0.012], death from cardiovascular causes (HR 0.55, 95% CI 0.36–0.90; P = 0.017), heart failure (HR 0.60, 95% CI 0.37–0.93; P = 0.023) and major adverse events (HR 0.66, 95% CI 0.49–0.91; P = 0.009). There was no difference in the rates of myocardial infarction and repeat revascularization.CONCLUSIONSMild LVSD was associated with a worse mid-term prognosis in patients following CABG.     

Eleven-year outcomes of U-clips in totally robotic coronary artery bypass grafting versus standard hand-sewn running suture in robotic-assisted coronary artery bypass grafting

 Open in a separate windowOBJECTIVESThe aim of this study was to evaluate the clinical outcomes of patients undergoing off-pump robotic coronary artery bypass grafting (CABG) with either interrupted nitinol U-Clips in totally endoscopic coronary artery bypass (TECAB) or standard running suture anastomosis in robotically assisted direct coronary artery bypass (RADCAB) over a decade.METHODSFrom January 2007 to December 2017, 280 patients underwent robotic off-pump CABG using the da Vinci S/Si Surgical System in our centre. TECAB with interrupted nitinol U-Clips anastomosis was performed in the left internal mammary artery (LIMA) to LAD grafting in 126 patients and RADCAB (n = 154) of the LIMA to LAD was completed with standard running suture. After discharge, patients were contacted through telephone interview and were invited to attend the outpatient clinic every 6 months or 1 year. The graft patency was assessed by coronary angiography or computed tomography angiography.RESULTSAll cases were completed without conversion to median sternotomy or cardiopulmonary bypass. A total of 275 single internal mammary artery (IMA) grafts (271 LIMAs, 4 right internal mammary arteries) and 5 bilateral IMA grafts were used as single graft or composite grafts. All the patients were discharged without in-hospital mortality or adverse outcomes. The average follow-up was 89.7 ± 30.4 months (range, 14–143 months). The cumulative survival rates (P = 0.53), the cumulative IMA patency rates (P = 0.83), and the rates of freedom from major adverse cerebrovascular and cardiovascular events (P = 0.41) between TECAB and RADCAB all showed no significant difference in the follow-up.CONCLUSIONSRobotic off-pump CABG using IMA grafts is safe and can provide reliable long-term outcomes. Compared with the standard hand-sewn running suture technique in RADCAB, interrupted suture with the nitinol U-Clips in TECAB showed similar long-term clinical results and graft patency in LIMA to LAD bypass grafting.     

Minimally invasive coronary artery bypass grafting via a lower ministernotomy for left anterior descending artery myocardial bridging: mid-term results

Open in a separate window OBJECTIVESCoronary artery bypass grafting or supra-arterial myotomy is now suggested as a better therapeutic option in myocardial bridging (MB) when medical treatment fails to control symptoms. For left anterior descending (LAD) MB, minimally invasive coronary artery bypass via a lower ministernotomy can be offered.METHODSForty-four consecutive patients who underwent elective minimally invasive coronary artery bypass surgery from 2005 to 2014 via an inferior sternotomy using the left internal mammary artery as a bypass graft for LAD MB were evaluated retrospectively.RESULTSThe mean age was 59.1 ± 13.1 years with 26 (59%) men and 18 (41%) women. The mean body mass index was 27.2 ± 3.9 and the mean EuroSCORE II was 1.6 ± 1.8. Routine coronary multislice computed tomography angiography on the 6th postoperative day revealed 97.7% graft patency. During the initial hospital stay, 1 patient (2.3%) underwent a reoperation for early graft failure. Forty patients (91%) could be followed up for a mean period of 64.4 ± 24.5 months after the procedure, during which 2 patients (4.5%) died of non-cardiac causes and 9 patients (20.5%) underwent postoperative coronary angiography with confirmed graft occlusion in only 1 case (2.3%). The improvement in the distribution of patients in the Canadian Cardiovascular Society class 0 was from 4 patients (9%) preoperatively to 37 patients (84%) at the end of the follow-up period (P-value 0.001).CONCLUSIONSMinimally invasive coronary artery bypass surgery via a lower ministernotomy may be safe and efficient for treating LAD artery MB with acceptable complication rates, cosmetic benefits and patency rates.     

Effect of a reduced donor heart right ventricular distensibility on post-heart transplant haemodynamics

Open in a separate window OBJECTIVESThis study aimed to investigate the characteristics of a reduced right ventricular distensibility after heart transplant.METHODSThis study enrolled 64 adult patients who underwent heart transplant at our institution. The degree of right ventricular distensibility was quantified by calculating the difference between right atrial pressures (RAPs) of X descent and Y descent (X–Y) from the RAP waveform in right heart catheterization. Histologically, the ratio of the interstitial tissue in myocardial biopsy samples was calculated.RESULTSOf the 64 patients, 35 (55%) had a reduced right ventricular distensibility at 1 week after heart transplant (X–Y > 1 mmHg, RD group), and 29 (45%) had a normal right ventricular distensibility (X–Y ≤ 1 mmHg, ND group). The mean RAP and mean pulmonary capillary wedge pressure 1 week after heart transplant in the RD group were significantly higher than that in the ND group. The mean RAP and mean pulmonary capillary wedge pressure in the RD group gradually normalized 12 weeks postoperation. The ratio of the interstitial tissue of biopsy samples significantly correlated with the X–Y value. The number of patients who required inotropic support >14 days was higher in the RD group than in the ND group.CONCLUSIONSReduced donor heart distensibility was a common impairment early after heart transplant. It might result from interstitial oedema in the myocardial tissue of the donor heart. Reduced donor heart distensibility after heart transplant might be associated with early clinical outcomes; however, further investigation is required.     

Magna ease bioprosthetic aortic valve: mid-term haemodynamic outcomes in 1126 patients

 Open in a separate windowOBJECTIVESThe Magna Ease aortic valve (Edwards Lifesciences, Irvine, CA) is a third-generation bioprosthetic valve developed as a modification of the well-studied Perimount and Magna valve designs. This study’s objective is to evaluate a large, single-centre experience with Magna Ease aortic valve replacement (AVR) focusing on clinical outcomes and haemodynamic performance.METHODSAll patients undergoing AVR between 8/2010 and 10/2018 at our institution implanted with the Magna Ease valve were included except those undergoing ventricular assist device or congenital aortic surgery. Primary outcomes were overall survival and freedom from reoperation. Mean transprosthetic gradient (mTPG) and structural valve deterioration (SVD) served as secondary outcomes.RESULTSTotally 1126 consecutive implantations of Magna Ease valves were included. Concomitant procedures were performed in 56.5% (n = 636). No severe patient–prosthesis mismatch (PPM) was present at implantation. Overall survival at 30 days, 1 year, 5 years and 9 years was 97.2%, 95.0%, 86.1% and 78.2%, respectively, with improved survival for isolated AVR. Total of 2.4% (n = 27) of patients required reoperation with 0.3% (n = 4) for SVD. Echocardiographic follow-up data revealed low mTPG throughout the study period. SVD occurred in 28.7% of patients at a mean of 3.9 years post implantation. CONCLUSIONSMagna Ease AVR maintained low mean transprosthetic gradients throughout mid-term evaluation and was associated with excellent overall survival and freedom from reoperation at nine years post implantation.     

Atrial and ventricular flows across a transcatheter mitral valve

 Open in a separate windowOBJECTIVESThe objective of this study was to evaluate the haemodynamic performance of transcatheter mitral valve replacement (TMVR) Implant with a focus on turbulence and washout adjacent to the ventricular surface of the leaflets. TMVR holds the promise of treating a large spectrum of mitral valve diseases. However, the haemodynamic performance and flow dynamics of such replacements are not fully understood. METHODSA tri-leaflet biopsrosthetic TMVR represented by Caisson implant of size 36A was implanted in the mitral position of a left heart simulator pulse duplicating system under physiological conditions. The 36A implant covers an anterior–posterior range of 26–32 mm and a commissure-to-commissure range of 30–36 mm. Transmitral pressure gradient, effective orifice area and regurgitant fraction were calculated. Particle image velocimetry was performed to evaluate turbulence in 2 perpendicular planes (Reynolds and viscous shear stresses, respectively). Additionally, dye experiments were performed to visualize washout.RESULTSTransmitral pressure gradient was 1.29 ± 0.27 mmHg and effective orifice area was 2.96 ± 0.28 cm². Regurgitant fraction was 14.13 ± 0.08%. Total washout was 4.27 cardiac cycles. Largest viscous shear stress reaches 3.7 Pa and 2.4 Pa in ventricle and atrium, respectively. Reynolds shear stress in the atrial side was <10 Pa. In the ventricular side, the largest Reynolds shear stress reached ∼35 Pa.CONCLUSIONSTMVR leads to favourable haemodynamics with low degree of turbulence combined with fast washout around the leaflets indicating promising potential for freedom from blood damage potential and thrombosis corroborated by initial clinical studies as part of the valves’s Early Feasibility Study.     

Correlation of ventricular septal defect height and outcomes after complete atrioventricular septal defect repair

 Open in a separate windowOBJECTIVESThere are limited data available on the height of the ventricular component of the septal deficiency (VSD) in patients undergoing complete atrioventricular septal defect (CAVSD) repair. VSD height may influence optimal choice of repair strategy with potential consequences for long-term outcomes. We aimed to measure VSD height using 2-dimensional echocardiography and review its association with postoperative outcomes.METHODSWe retrospectively reviewed the preoperative echocardiograms of 45 consecutive patients who underwent CAVSD repair between May 2010 and December 2015 at a single centre. VSD height and left ventricular length on the four-chamber view were measured. Demographic details and early and late outcomes including reoperation and long-term survival were studied.RESULTSTwenty patients underwent modified single-patch repair and 25 patients underwent double-patch repair of CAVSD. VSD height in the modified single-patch group ranged from 4.2 to 11.7 mm and in the double-patch group ranged from 5.1 to 14.9 mm. Nine patients had a deep ‘scoop’ with a VSD height of >10 mm, (7 double patch, 2 modified single patch). VSD height did not correlate with a specific Rastelli classification. There was no significant difference in the VSD height (P = 0.51) or the VSD height-to-left ventricular length ratio (P = 0.43) between the 2 repair groups. There was no 30-day mortality. Eight patients required reoperation; however, VSD height was not a significant predictor of reoperation (hazard ratio 0.95, 95% confidence interval 0.69–1.33; P = 0.08).CONCLUSIONSThere was no correlation between VSD height and risk of reoperation after CAVSD repair. A deep ventricular scoop is uncommon in CAVSD patients.     

Re-dosing of del Nido cardioplegia in adult cardiac surgery requiring prolonged aortic cross-clamp

Open in a separate window OBJECTIVESFew data exist on the use of del Nido cardioplegia in adults, specifically during operations requiring prolonged aortic cross-clamp. In this pilot study, we evaluate outcomes of patients undergoing surgery with cross-clamp time >3 h based on re-dosing strategy, using either full dose (FD; 1:4 blood to crystalloid ratio) or dilute (4:1 blood to crystalloid ratio) solution.METHODSConsecutive adult patients (>18 years) undergoing cardiac surgery from 2012 to 2018 with cross-clamp time >3 h were reviewed. Patients were excluded if del Nido cardioplegia was not used. Patients were categorized into FD or dilute groups based on re-dosing solution. Propensity score matching was used to control for baseline differences between groups. The primary endpoint was in-hospital mortality. Other outcomes examined included: postoperative mechanical support, arrhythmia, stroke, dialysis and cardiac function.RESULTSIncluded for analysis were 173 patients (115 male) with median age of 63.8 (interquartile range 53.9–73.1). Major comorbidities included diabetes (45), cerebrovascular disease (34), hypertension (131), atrial fibrillation (52) and previous cardiac surgery (83). There were 108 patients (62%) who received FD re-dosing, while 65 (38%) received dilute. A greater proportion of patients in the dilute group received retrograde delivery, for both induction (32/108 vs 39/65, P < 0.001) and re-dose (50/108 vs 53/65, P < 0.001). After propensity score matching, in-hospital mortality was not different between groups (6/48 vs 1/48, P = 0.131). There were no differences in rates of postoperative mechanical circulatory support, stroke, left ventricular ejection fraction or right ventricle dysfunction.CONCLUSIONSDel Nido cardioplegia has been used in complex cardiac surgery requiring prolonged cross-clamp. Re-dosing can be performed with either FD or dilute del Nido solution with no statistical difference in outcomes.     

Long-term viability and extensibility of an in situ regenerated canine aortic wall using hybrid warp-knitted fabric

Open in a separate window OBJECTIVESMany surgical materials promoting tissue regeneration have been explored for use in paediatric cardiac surgery. The aim of this study is to evaluate the long-term viability and extensibility of the canine aortic wall regenerated using a novel synthetic hybrid fabric.METHODSThe sheet is a warp-knitted fabric of biodegradable (poly-l-lactic acid) and non-biodegradable (polyethylene terephthalate) yarns coated with cross-linked gelatine. This material was implanted as a patch to fill an oval-shaped defect created in the canine descending aorta. The tissue samples were explanted after 12, 24 or 36 months (N = 3, 2, 2, respectively) for histological examination and biomechanical testing.RESULTSThere was no shrinkage, rupture or aneurysmal change after 24 months. The regenerated wall showed prototypical vascular healing without material degeneration, chronic inflammation, calcification or abnormal intimal overgrowth. Bridging tissue across the patch was well-formed and had expanded over time. The biodegradable yarns had completely degraded at 24 months after implantation, as scheduled, but the regenerated aortic wall demonstrated satisfactory levels of mechanical strength and extensibility in tensile strength tests.CONCLUSIONSThe sheet achieved good long-term viability and extensibility in the regenerated aortic wall. These findings suggest that it is a promising surgical material for repairing congenital heart defects. Further developments of the sheet are required, including clinical studies.