Postoperative autotransfusion of mediastinal shed blood does not influence haemostasis after elective coronary artery bypass grafting

Objectives: The rationale of using autotransfusion of mediastinal shed blood after cardiac surgery is to preserve haemoglobin levels and reduce the need for allogenic blood transfusions. However, the method is controversial and its clinical value has been questioned. We hypothesised that re-transfusion of mediastinal shed blood instead impairs haemostasis after routine coronary artery bypass grafting and thus increases postoperative bleeding. Methods: Seventy-seven consecutive elective coronary artery bypass surgery patients (mean age 67 ± 9 years, 77% men) were included in a prospective, randomised controlled study. The patients were randomised to postoperative re-transfusion of mediastinal shed blood (n = 39) or to a group where mediastinal shed blood was discarded (n = 38). Primary end point was bleeding during the first 12 postoperative hours. Secondary end points were postoperative transfusion requirements, haemoglobin levels, thrombo-elastometric variables and plasma concentrations of interleukin-6, thrombin–anti-thrombin complex and D-dimer. Results: Mean re-transfused volume in the autotransfusion group was 282 ± 210 ml. There was no difference in postoperative bleeding (median 394 ml (interquartile range 270–480) vs 385 (255–430) ml, p = 0.69), proportion of patients receiving transfusions of blood products (11/39 vs 11/38, p = 0.95), haemoglobin levels 24 h after surgery (116 ± 13 vs 116 ± 14 g l⁻¹, p = 0.87), thrombo-elastometric variables, interleukin-6 (219 ± 144 vs 201 ± 144 pg ml⁻¹, p = 0.59), thrombin–anti-thrombin complex (11.0 ± 9.1 vs 14.8 ± 15, p = 0.19) or D-dimer (0.56 ± 0.49 vs 0.54 ± 0.44, p = 0.79) between the autotransfusion group and the no-autotransfusion group. Conclusions: Autotransfusion of small-to-moderate amounts of mediastinal shed blood does not influence haemostasis after elective coronary artery bypass grafting.     

Tricuspid valve surgery: a thirty-year assessment of early and late outcome

Objective: Tricuspid valve (TV) surgery is usually performed as a concomitant reconstruction procedure in addition to the correction of other cardiac pathologies. Isolated tricuspid procedures are exceptionally rare. Prosthetic valve replacement is also seldom required. Generally, these patients face a high risk of operative mortality and long-term outcome is poor. In this study we reviewed our experience with TV surgery focusing on risk factors for operative mortality, long-term outcome and incidence of valve related complications Methods: Retrospective analysis of 416 consecutive patients >18 years with acquired TV disease operated on between 1974 and 2003. The follow-up is 97% complete (mean 5.9 ± 6.3 years). Three hundred and sixty-six patients (88%) underwent TV surgery with concomitant mitral (n = 340) or aortic (n = 100) valve surgery. The tricuspid valve was repaired in 310 patients (74.5%) and replaced in 106 (25.5%). A biological prosthesis was used in 68 patients (64%). Mean age at repair and replacement was 61 ± 12.5 and 50 ± 11.3 years, respectively (p < 0.001). Results: Overall 30-day mortality was 18.8% (78/416) and decreased from 33.3% (1974–1979) to 11.1% (2000–2003) (p ≤ 0.0001). Thirty-day mortality after TV repair and replacement was 13.9% (43/310) and 33% (35/106), respectively (p ≤ 0.001). Cox regression analysis revealed TV replacement as an independent predictor of 30-day mortality. Ten-year actuarial survival after TV repair and replacement was 47 ± 3.5% and 37 ± 4.8%, respectively (p = 0.002). Forty-five patients (10.8%) required a TV re-operation after 7.7 ± 5.1 years. Freedom from TV re-operation 10 years after TV repair and replacement was 83 ± 3.6% and 79 ± 6.1%, respectively (p = 0.092). Conclusions: Patients who require tricuspid valve surgery constitute a high-risk group. Tricuspid valve repair is associated with better perioperative and long-term outcome than valve replacement. However, patients undergoing replacement showed a significant higher incidence of risk factors for operative mortality. The incidence of re-operation is low with no significant difference when the tricuspid valve has been repaired or replaced. When valve replacement is necessary we recommend the use of a biological prosthesis considering the poor long-term survival.     

Comparison of outcomes of minimally invasive mitral valve surgery for posterior, anterior and bileaflet prolapse

Objective: We sought to compare the outcomes of minimally invasive mitral valve (MV) surgery for anterior (anterior mitral leaflet, AML), posterior (posterior mitral leaflet, PML) or bileaflet (BL) MV prolapse. Methods: Between August 1999 and December 2007, 1230 patients who presented with isolated AML (n = 156, 12.7%), isolated PML (n = 672, 54.6%) or BL (n = 402, 32.7%) MV prolapse underwent minimally invasive MV surgery. The preoperative mitral regurgitation (MR) grade was 3.3 ± 0.8, left ventricular ejection fraction (LVEF) was 62 ± 12% and mean age was 58.9 ± 13.0 years; 836 patients (68.0%) were male. Mean follow-up time was 2.7 ± 2.1 years, and the follow-up was 100% complete. Results: Overall, the MV repair rate was 94.0% (1156 patients). Seventy-four patients (6.0%) received MV replacement. MV repair for PML prolapse was accomplished in 651 patients (96.9%), for AML in 142 patients (91%) and for BL in 363 patients (90.3%). Repair techniques consisted predominantly of leaflet resection and/or implantation of neochordae, combined with ring annuloplasty. Concomitant procedures were tricuspid valve surgery (n = 56), atrial fibrillation ablation (n = 286) and closure of an atrial septal defect or patent foramen ovale (PFO) (n = 89). The overall duration of cardiopulmonary bypass was 127 ± 40 min and aortic cross-clamp time was 78 ± 33 min. The mean postoperative hospital stay was 11.6 ± 9.7 days for the overall group. Early echocardiographic follow-up revealed excellent valve function in the vast majority of patients, regardless of the repair technique, with a mean MR grade of 0.3 ± 0.5. For the overall group, 5-year survival rate was 87.3% (95% CI: 83.9–90.1) and 5-year freedom from cardiac reoperation rate was 95.6% (95% CI: 94.1–96.7). The log-rank test revealed no significant difference between the three groups regarding long-term survival or freedom from reoperation. Conclusions: Minimally invasive MV repair can be achieved with excellent results. Long-term outcomes and reoperation rates for AML prolapse are not significantly different from PML or BL prolapse.     

Assessment of aortic annulus dimensions for Edwards SAPIEN Transapical Heart Valve implantation by computed tomography: calculating average diameter using a virtual ring method

Objective: Accurate preoperative assessment of the aortic annulus dimensions is critical in patients undergoing transcatheter aortic valve implantation (TAVI) for severe AS. Using multislice computed tomography (MSCT), we evaluated a novel approach to quantify aortic annulus dimensions using cross-sectional area (CSA) assessment and average diameter calculation compared with the commonly applied electronic caliper measurements in patients undergoing transapical implantation of the Edwards SAPIEN Transcatheter Heart Valve. Methods: Seventy-one patients underwent pre-TAVI MSCT with the following dimensions assessed at the level of the most basal attachment points of all three aortic cusps joined by a virtual ring: CSA, calculated average annulus diameter (CAAD), and minimal, maximum, sagittal and coronal diameters. Measurements were compared with post-TAVI MSCT data sets at the level of the ventricular stent ending in 24 patients. Pre-TAVI measurements were compared to those taken post-TAVI. Eligibility to balloon-expandable TAVI was evaluated based on the different measurements. Results: The Edwards SAPIEN valve (23 mm, n = 8; 26 mm, n = 16) was implanted 2.1 ± 1.1 mm below the non-coronary sinus. Pre-TAVI CAAD was 23.0 ± 1.6 mm; post-TAVI CAAD was 23.0 ± 1.1 mm. Post-TAVI CSA was circular in 18 patients (75%) and ovoid in six (25%). Pre- and post-TAVI assessment showed strong correlation for CSA and CAAD (r = 0.835, p < 0.001; r = 0.841, p < 0.001, respectively). Minimal, maximum, coronal and sagittal dimension correlated weakly between pre- and post-TAVI measurements (r = 0.435–0.632, p = 0.001–0.034). Conclusion: Pre-TAVI CSA assessment and average diameter calculation using a virtual ring method is able to predict the post-interventional configuration of the annulus after balloon-expandable TAVI. We regard this approach as the best-available method to select the appropriate prosthesis size for balloon-expandable TAVI. Specific MSCT-based sizing recommendations should be developed.     

A new self-expanding aortic stent valve with annular fixation: in vitro haemodynamic assessment

Objective: Balloon-expandable stent valves require flow reduction during implantation (rapid pacing). The present study was designed to compare a self-expanding stent valve with annular fixation versus a balloon-expandable stent valve. Methods: Implantation of a new self-expanding stent valve with annular fixation (Symetis^®, Lausanne, Switzerland) was assessed versus balloon-expandable stent valve, in a modified Dynatek Dalta^® pulse duplicator (sealed port access to the ventricle for transapical route simulation), interfaced with a computer for digital readout, carrying a 25 mm porcine aortic valve. The cardiovascular simulator was programmed to mimic an elderly woman with aortic stenosis: 120/85 mmHg aortic pressure, 60 strokes/min (66.5 ml), 35% systole (2.8 l/min). Results: A total of 450 cardiac cycles was analysed. Stepwise expansion of the self-expanding stent valve with annular fixation (balloon-expandable stent valve) resulted in systolic ventricular increase from 120 to 121 mmHg (126 to 830 ± 76 mmHg)*, and left ventricular outflow obstruction with mean transvalvular gradient of 11 ± 1.5 mmHg (366 ± 202 mmHg)*, systolic aortic pressure dropped distal to the valve from 121 to 64.5 ± 2 mmHg (123 to 55 ± 30 mmHg) N.S., and output collapsed to 1.9 ± 0.06 l/min (0.71 ± 0.37 l/min* (before complete obstruction)). No valve migration occurred in either group. (* = p < 0.05). Conclusions: Implantation of this new self-expanding stent valve with annular fixation has little impact on haemodynamics and has the potential for working heart implantation in vivo. Flow reduction (rapid pacing) is not necessary.     

Is tricuspid valve replacement a catastrophic operation?

Objective: Tricuspid valve replacement (TVR) has a high postoperative mortality, despite recent advances in perioperative care. We report the results of our experience in TVR with an emphasis on early mortality and morbidity and long-term follow-up. Methods: Between October 1994 and August 2007, 80 consecutive TVRs were performed in 78 patients. The mean age was 48 ± 14 (range: 20–70) years. The underlying disease of the patients was classified as rheumatic (n = 54), congenital (n = 12), endocarditis (n = 10) or degenerative (n = 4). Previous cardiac surgery had been performed in 40 patients (50%). Isolated TVR was performed in 24 patients (30%). Results: Hospital mortality occurred in one patient (1.4%). Postoperative morbidities included intra-aortic balloon pump (n = 5), bleeding re-operation (n = 4), delayed sternal closure (n = 3), acute renal failure (n = 3), subdural haematoma (n = 3), extracorporeal membrane oxygenation (n = 1), mediastinitis (n = 1) and pacemaker insertion (n = 4). In 42 patients, ventilator support was needed for more than 72 h. Based on multivariate analysis, age (p < 0.001) and the cardiopulmonary time (p = 0.004) were the identified risk factors. Follow-up was completed in all patients with a mean duration of 56 ± 37 (range: 0–158) months. During the follow-up period, there were seven deaths (8.8%), including five cardiac deaths. The 5- and 8-year survival rates were 95 ± 3% and 79 ± 9% and event-free survival rates were 76 ± 6% and 61 ± 9%, respectively. Based on multivariate analysis, the only identified predictors of late deaths was a postoperative low cardiac output (p = 0.024). Conclusions: TVR can be performed and low operative mortality can be achieved thorough optimal perioperative management in the current era.     

Intracardiac allogeneic mesenchymal stem cell transplantation elicits neo-angiogenesis in a fully immunocompetent ischaemic swine model

Objectives: Autologous mesenchymal stem cell transplantation has been shown to improve myocardial function in ischaemic cardiomyopathy. We studied one hypothetical mechanism, neo-angiogenesis, using allogeneic mesenchymal stem cell transplantation in an ischaemic swine model. Methods: Allogeneic mesenchymal stem cells were injected in the peri-infarct area (1 × 10⁶ cells kg⁻¹) 2 weeks after myocardial infarction. Myocardial infarction alone (n = 3) served as a control group. In the myocardial infarction–mesenchymal stem cells group (n = 6), tacrolimus was given from day 0 to day 12. Capillary density and inflammatory/rejection processes (anti-factor VIII and anti-CD3/CD68 monoclonal antibodies, respectively) were compared between groups. Results: In scarred myocardium, capillary density was similar between both ischaemic groups: 15.4 (±15.3) and 14.7 (±15.2) vessel/field in myocardial infarction–mesenchymal stem cells and myocardial infarction-alone groups (non-significant). In viable myocardium adjacent to the infarction, capillary density was significantly increased in the myocardial infarction–mesenchymal stem cells group than in the myocardial infarction-alone group (p = 0.002). The number of infiltrating CD3+ cells was equivalent in both myocardial infarction-alone and myocardial infarction–mesenchymal stem cells groups (CD3+: 8.6% vs 9.3%, non-significant). However, CD68+ cell infiltration was more prominent after mesenchymal stem cell transplantation (4.7% vs 2% in myocardial infarction alone, p < 0.01). Conclusions: Allogeneic mesenchymal stem cell transplantation enhances angiogenesis after myocardial infarction. This effect is limited to the viable myocardium. Using a concomitant 12-day course of tacrolimus, no mesenchymal stem cell-specific cellular immune response was demonstrated.     

Long-term outcome after pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension: a single institution experience

Objective: Pulmonary endarterectomy (PEA) for chronic thromboembolic pulmonary hypertension (CTEPH) is the first treatment of choice with good short-term results. Only limited data are available concerning the long-term outcome after PEA. The purpose of this study is to evaluate the long-term survival and functional outcome after PEA with nearly 10 years experience. Method: In the period of December 1998 and December 2007 120 patients with CTEPH were referred to the St Antonius Hospital (Nieuwegein, The Netherlands) of whom 72 underwent PEA. The clinical data are collected retrospectively. Results: In-hospital mortality was (5/72) 6.9%. Since 2004 one patient died in the hospital (1/38, 2.9%). Two patients died during long-term follow-up with a median observation of 3 years. The overall 1-, 3- and 5-year survival rates were 93.1%, 91.2% and 88.7% respectively. Prior to surgery patients were in New York Heart Association functional class III (58) and IV (14) with a mean pulmonary vascular resistance of 572 ± 313 dynes s cm⁻⁵. The following data were compared before and after operation: mean pulmonary artery pressure (mPAP) decreased from 42 ± 11 to 22 ± 7 mmHg (p = 0.0001), NT-pro BNP improved from 1527 ± 1652 to 160 ± 3 pg/ml (p = 0.0001), 6 min walk distance (6MWD) from 359 ± 124 to 518 ± 11 m (p = 0.0001), and almost all patients returned to functional class I or II (p = 0.0001). Conclusion: Pulmonary endarterectomy for patients with CTEPH has shown a dramatic improvement of clinical status with excellent long-term survival.     

The mode of death in the non-heart-beating donor has an impact on lung graft quality

Objective: We hypothesised that the agonal phase prior to cardiac death may negatively influence the quality of the pulmonary graft recovered from non-heart-beating donors (NHBDs). Different modes of death were compared in an experimental model. Methods: Non-heparinised pigs were divided into three groups (n = 6 per group). Animals in group I [FIB] were sacrificed by ventricular fibrillation resulting in immediate circulatory arrest. In group II [EXS], animals were exsanguinated (45 ± 11 min). In group III [HYP], hypoxic cardiac arrest (13 ± 3 min) was induced by disconnecting the animal from the ventilator. Blood samples were taken pre-mortem in HYP and EXS for measurement of catecholamine levels. After 1 h of in situ warm ischaemia, unflushed lungs were explanted and stored for 3 h (4 °C). Left lung performance was then tested during 60 min in our ex vivo reperfusion model. Total protein concentration in bronchial lavage fluid was measured at the end of reperfusion. Results: Pre-mortem noradrenalin (mcg l⁻¹) concentration (baseline: 0.03 ± 0) increased to a higher level in HYP (50 ± 8) vs EXS (15 ± 3); p = 0.0074. PO₂ (mmHg) at 60 min of reperfusion was significantly worse in HYP compared to FIB (445 ± 64 vs 621 ± 25; p < 0.05), but not to EXS (563 ± 51). Pulmonary vascular resistance (dynes s cm⁻⁵) was initially higher in EXS (p < 0.001) and HYP (NS) vs FIB (15824 ± 5052 and 8557 ± 4933 vs 1482 ± 61, respectively) but normalised thereafter. Wet-to-dry weight ratio was higher in HYP compared to FIB (5.2 ± 0.3 vs 4.7 ± 0.2, p = 0.041), but not to EXS (4.9 ± 0.2). Total protein (g l⁻¹) concentration was higher, although not significant in HYP and EXS vs FIB (18 ± 6 and 13 ± 4 vs 4.5 ± 1.3, respectively). Conclusion: Pre-mortem agonal phase in the NHBD induces a sympathetic storm leading to capillary leak with pulmonary oedema and reduced oxygenation upon reperfusion. Graft quality appears inferior in NHBD lungs when recovered in controlled (HYP) vs uncontrolled (EXS and FIB) setting.     

Balloon-expanding transcatheter aortic valve implantation for degenerated Mitroflow bioprostheses: clinical and echocardiographic long-term outcomes

Open in a separate window OBJECTIVESThis study aims to analyse the risks associated with valve-in-valve procedures for treating structural valve deterioration in Mitroflow bioprostheses, as well as to determine the impact of the original Mitroflow size on the patients’ long-term outcomes.METHODSBetween January 2012 and September 2019, 21 patients (61.9% males; mean age 82.4 ± 5.4 years) were treated for Mitroflow deterioration with valve-in-valve procedures (12 transapical and 9 transfemoral).RESULTSMean EuroSCORE I and EuroSCORE II were 28.2% ± 13.6% and 10.5% ± 6.1%, respectively. Six patients presented an indexed aortic root diameter <14 mm/m² and 7 patients a diameter of sinus of Valsalva <30 mm. Implanted transcatheter valve sizes were 20 mm in 6 cases, 23 mm in 14 cases and 26 mm in 1 patient. A Valve Academic Research Consortium-2 complication occurred in 23.8% of cases, including 3 coronary occlusions. In-hospital mortality was 9.5%. The 20 mm transcatheter valves presented significantly higher postoperative peak and mean aortic gradients than other sizes (54.1 ± 11.3 mmHg vs 29.9 ± 9.6 mmHg, P = 0.003; and 29.3 ± 7.7 mmHg vs 17.4 ± 5.9 mmHg, P = 0.015, respectively). There were 12 cases of patient–prosthesis mismatch (57.1%) and 3 cases (14.3%) of severe patient–prosthesis mismatch. Cumulative survival was 85.7% ± 7.6% at 1 year, 74.3% ± 10% at 2 years and 37.1% ± 14.1% at 5 years.CONCLUSIONSValve-in-valve procedures with balloon-expandable transcatheter valves associate a high risk of coronary occlusion in patients with indexed aortic root diameter <14 mm/m² and low coronary ostia <12 mm. Valve-in valve procedures with 20 mm balloon-expandable transcatheter valves in ≤21 mm Mitroflow bioprosthesis leave significant residual transvalvular gradients that might obscure patients’ long-term outcomes.     

Minimised versus conventional cardiopulmonary bypass: outcome of high-risk patients

Background: Coronary artery bypass grafting (CABG) with extracorporeal circulation (ECC) is the gold standard for surgical coronary re-vascularisation. Recently, minimised extracorporeal circulation system (MECC) has been postulated a safe and advantageous alternative for multi-vessel CABG. Method: Between January 2004 and December 2007, 244 high-risk patients (logistic EuroScore (ES) > 10%) underwent CABG in our institution. ECC was used in 139 (57%) and MECC in 105 (43%) patients. Demographic data including age (MECC: 73.4 ± 7.4 years; ECC: 73.3 ± 6.4 years), ES (MECC: 19.2 ± 9.8%; ECC: 21.4 ± 11.9%), left-ventricular ejection fraction (MECC: 45.6 ± 16.1%; ECC: 43.1 ± 15.3%), diabetes mellitus (MECC: 14.3%; ECC: 15.1%) and COPD (MECC: 6.7%; ECC: 7.9%) did not differ between the two groups. Preoperative end-stage renal failure was an exclusion criterion. The clinical course and serological/haematological parameters in the ECC and MECC patients were compared in a retrospective manner. Results: Although the numbers of distal anastomoses did not differ between the two groups (MECC: 3.0 ± 0.9; ECC: 2.9 ± 0.9), ECC time was significantly shorter in the MECC group (MECC: 96 ± 33 min; ECC: 120 ± 50 min, p < 0.01). Creatinine kinase (CK) levels were significantly lower 6 h after surgery in the MECC group (MECC: 681 ± 1505 U l⁻¹; ECC: 1086 ± 1338 U l⁻¹, p < 0.05) and the need of red blood cell transfusion was significantly less after MECC surgery (MECC: 3 [range: 1–6]; ECC: 5 [range: 2–9] p < 0.05). Moreover, 30-day mortality was significantly lower in the MECC group as compared to the ECC group (MECC: 12.4%; ECC: 26.6, p < 0.01). Discussion: MECC is a safe alternative for CABG surgery. A lower 30-day mortality, lower transfusion requirements and less renal and myocardial damage encourage the use of MECC systems, especially in high-risk patients.     

Brain preservation with selective cerebral perfusion for operations requiring circulatory arrest: protection at 25 °C is similar to 18 °C with shorter operating times

Background: Hypothermic circulatory arrest (HCA) is employed for aortic arch and other complex operations, often with selective cerebral perfusion (SCP). Our previous work has demonstrated real-time evidence of improved brain protection using SCP at 18 °C. The purpose of this study was to evaluate the utility of SCP at warmer temperatures (25 °C) and its impact on operating times. Methods: Piglets undergoing cardiopulmonary bypass (CPB) and 60 min of HCA were assigned to three groups: 18 °C without SCP, 18 °C with SCP and 25 °C with SCP (n = 8 animals per group). CPB flows were 100 ml kg⁻¹ min⁻¹ using pH-stat management. SCP flows were 10 ml kg⁻¹ min⁻¹ via the innominate artery. Cerebral oxygenation was monitored using NIRS (near-infrared spectroscopy). A microdialysis probe placed into the cerebral cortex had samples collected every 15 min. Animals were recovered for 4 h after separation from CPB. All data are presented as mean ± standard deviation (SD; p < 0.05, significant). Results: Cerebral oxygenation was preserved during deep and tepid HCA with SCP, in contrast to deep HCA without SCP (p < 0.05). Deep HCA at 18 °C without SCP resulted in significantly elevated brain lactate (p < 0.01) and glycerol (p < 0.01), while the energy substrates glucose (p < 0.001) and pyruvate (p < 0.001) were significantly depleted. These derangements were prevented with SCP at 18 °C and 25 °C. The lactate/pyruvate ratio (L/P) was profoundly elevated following HCA alone (p < 0.001) and remained persistently elevated throughout recovery (p < 0.05). Piglets given SCP during HCA at 18 °C and 25 °C maintained baseline L/P ratios. Mean operating times were significantly shorter in the 25 °C group compared to both 18 °C groups (p < 0.05) without evidence of significant acidemia. Conclusion: HCA results in cerebral hypoxia, energy depletion and ischaemic injury, which are attenuated with the use of SCP at both 18 °C and 25 °C. Procedures performed at 25 °C had significantly shorter operating times while preserving end organs.     

An initial evaluation of post-cardiopulmonary bypass acute kidney injury in swine

Objective: Acute kidney injury (AKI) post-cardiac surgery is associated with mortality rates approaching 20%. The development of effective treatments is hindered by the poor homology between rodent models, the mainstay of research into AKI, and that which occurs in humans. This pilot study aims to characterise post-cardiopulmonary bypass (CPB) AKI in an animal model with potentially greater homology to cardiac surgery patients. Methods and results: Adult pigs, weighing 50–75 kg, underwent 2.5 h of CPB. Pigs undergoing saphenous vein grafting procedures served as controls. Pre-CPB measures of porcine renal function were within normal ranges for adult humans. The effect of CPB on renal function; a 25% reduction in ⁵¹Cr-EDTA clearance (p = 0.068), and a 33% reduction in creatinine clearance (p = 0.043), was similar to those reported in clinical studies. CPB resulted in tubular epithelial injury (median NAG/creatinine ratio 2.6 u mmol⁻¹ (interquartile range (IQR): 0.81–5.43) post-CPB vs 0.48 u mmol⁻¹ (IQR: 0.37–0.97) pre-CPB, p = 0.043) as well as glomerular and/or proximal tubular injury (median albumin/creatinine ratio 6.8 mg mmol⁻¹ (IQR: 5.45–13.06) post-CPB vs 1.10 mg mmol⁻¹ (IQR: 0.05–2.00) pre-CPB, p = 0.080). Tubular injury scores were significantly higher in kidneys post-CPB (median score 2.0 (IQR: 1.0–2.0) relative to vein graft controls (median score 1.0 (IQR 1.0–1.0), p = 0.019). AKI was associated with endothelial injury and activation, as demonstrated by reduced DBA (dolichos biflorus agglutinin) lectin and increased endothelin-1 and vascular cell adhesion molecule (VCAM) staining. Conclusions: The porcine model of post-CPB AKI shows significant homology to AKI in cardiac surgical patients. It links functional, urinary and histological measures of kidney injury and may offer novel insights into the mechanisms underlying post-CPB AKI.     

During treatment protocol for univentricular heart serum levels of natriuretic peptides decrease

Objective: In children treated for univentricular heart (UVH), prospective evaluation of serum levels of N-terminal proatriopeptide (ANPN) and N-terminal pro-brain natriuretic peptide (NT-proBNP) was performed. Methods: Serum samples were analysed in 19 children before the first operation, before the bi-directional Glenn (BDG) operation, at age 1 year and before total cavopulmonary connection (TCPC). In addition, we performed cross-sectional measurement of peptide levels in 32 children: 22 hypoplastic left ventricle (LV), 10 hypoplastic right ventricle (RV) before; and in 12 children: nine hypoplastic LV, three hypoplastic RV, 2 (range: 0.5–5.3) years after the TCPC operation. Controls comprised 12 children aged less than 6 months and 41 children aged from 6 months to 7 years. Results: Between the first and second operations, peptide levels decreased. Before TCPC, further decreases had occurred. Throughout follow-up, peptide levels were higher than in controls. In the cross-sectional study, before TCPC, median ANPN concentration measured 0.37 (range: 0.18–1.00) nmol l⁻¹ (P = 0.059, compared with controls) and NT-proBNP 155 (range: 13–718) ng l⁻¹ (P < 0.001). After TCPC, median ANPN concentration measured 0.39 (range: 0.09–0.98) nmol l⁻¹ (P = ns) and NT-proBNP 201 (range: 76–1406) ng l⁻¹ (P < 0.001). Before TCPC, levels of NT-proBNP were higher in patients with RV than with LV morphology. Conclusions: Natriuretic peptide levels decreased during treatment protocol for UVH, but NT-proBNP levels remained higher than in controls. These reflect reduction of volume overload of the single ventricle and can prove useful for haemodynamic monitoring.     

Leucocyte filtration of salvaged blood during cardiac surgery: effect on red blood cell function in concentrated blood compared with diluted blood

Objective: Leucocyte filtration of salvaged blood has been suggested to prevent patients from receiving activated leucocytes during auto-transfusion in cardiac surgery. This study examines whether leucocyte filtration of salvaged blood affects the red blood cell (RBC) function and whether there is a difference between filtration of the concentrated and diluted blood on RBC function. Methods: Forty patients undergoing cardiac surgery with cardiopulmonary bypass were randomly divided into a group receiving leucocyte filtration of concentrated blood (High-Hct, n = 20) and another group receiving leucocyte filtration of the diluted blood (Low-Hct, n = 20). During operation, all the salvaged blood, as well as the residual blood, from the heart–lung machine was filtered. In the High-Hct group, blood was concentrated with a cell saver prior to filtration, whereas in the Low-Hct group, blood was filtered without concentration. RBC function was represented by RBC aggregation and deformability measured by a laser-assisted optical rotational cell analyser and by the RBC 2,3-diphosphoglycerate (2,3-DPG) and adenosine triphosphate (ATP) contents with conventional biochemical tests. Results: Leucocyte filtration of diluted blood with a low haematocrit (14 ± 4%) did not affect RBC function. However, when the concentrated blood with a high haematocrit (69 ± 12%) was filtered, there was a reduction of ATP content in RBCs after passing through the filter (from 1.45 ± 0.57 μmol g⁻¹ Hb to 0.92 ± 0.75 μmol g⁻¹ Hb, p < 0.05). For patients who received the concentrated blood, their in vivo RBC function did not differ from those who received diluted blood. Conclusions: Leucocyte filtration of the diluted salvaged blood during cardiac surgery does not affect RBC function, but it tends to deplete the ATP content of RBCs as the salvaged blood has been concentrated prior to filtration.     

Preoperative predictors of recurrent atrial fibrillation late after successful mitral valve reconstruction

Objective: Late outcome after mitral valve repair was examined to define preoperative predictors of recurrent atrial fibrillation late after successful mitral valve reconstruction. Methods: One hundred and eighty-nine patients, 112 with preoperative sinus rhythm and 72 with preoperative chronic or intermittent atrial fibrillation, were followed for 12.2±10 years after valve repair. Clinic, hemodynamic end echocardiographic data were entered into Cox-regression and Kaplan–Meyer analysis to assess predictors for recurrent atrial fibrillation late after successful mitral valve repair. Results: Univariate and multivariate predictors for recurrent atrial fibrillation late after successful mitral valve reconstruction were preoperative atrial fibrillation (P=0.0001), preoperative antiarrhythmic drug treatment (P=0.005), heart rate (P=0.01), left ventricular ejection fraction (P=0.01) and increased left ventricular posterior wall thickness (P=0.05). Patients>57.5 years with a mean pulmonary artery pressure ≥23mm Hg and a history of preoperative antiarrhythmic drug treatment had an odds ratio of 53.33 (95% confidence limits 6.12–464.54) for atrial fibrillation late after successful mitral valve repair. Conclusion: Older patients with a history of atrial fibrillation, antiarrhythmic treatment or an elevated pulmonary artery pressure may present atrial fibrillation late after successful mitral valve repair. They could be considered for combined mitral valve reconstruction and surgery for atrial fibrillation even though sinus rhythm is present preoperatively.     

Muscle Mass Is More Strongly Related to Hip Bone Mineral Density Than Is Quadriceps Strength or Lower Activity Level in Adults Over Age 50 Year

This cross-sectional study examined whether reduced hip bone mineral density (BMD) is better explained by isokinetic knee extensor strength (KES), lower limb lean body mass (L-LBM), or Physical Activity Scale for the Elderly (PASE). Through population-based recruitment, 1543 adults without knee osteoarthritis were recruited. For men and women respectively, means ± SD were age 60.8 ± 8.0 and 61.1 ± 7.9 yr; body mass index 29.6 ± 4.6 and 29.1 ± 5.4 kg/m²; hip BMD 1.025 ± 0.138 and 0.895 ± 0.128 g/cm²; KES 124.9 ± 41 and 72.7 ± 22.9 N·m; L-LBM 10.3 ± 1.5 and 7.0 ± 1.2 kg; and PASE 206.4 ± 99.7 and 163.8 ± 77.0. The relationship between BMD and KES in men (r² = 0.21, p ≥ 0.002) and women (r = 0.23, p < 0.001) was significant before adjustment. However, this association was no longer significant after controlling for L-LBM. Even after controlling for age, race, and sex, the association between BMD and KES was better explained by L-LBM (partial R² = 0.14, p < 0.001) than by PASE (partial R² = 0.00). Allometric scaling of KES to body size attenuated the association of BMD with KES (Std Beta = 0.03). The significant association between BMD and L-LBM (Std Beta = 0.36) remained stronger than that between BMD and weight (Std Beta = 0.21). Therefore, muscle mass accounted for a greater proportion of the variance in hip BMD than KES or activity level and explained a significant proportion of the association between weight and BMD.     

Long-term clinical outcome of mitral valve repair in asymptomatic severe mitral regurgitation

Objective: To assess the long-term survival, the incidence of cardiac complications and the factors that predict outcome in asymptomatic patients with severe degenerative mitral regurgitation (MR) undergoing mitral valve repair. Methods: Up to 143 asymptomatic patients (mean age 63 ± 12 years) with severe degenerative MR who underwent mitral valve repair between 1990 and 2001 were subsequently followed up for a median of 8 years. The study population was subdivided into three subgroups: patients with left ventricular (LV) dysfunction and/or dilatation (n = 18), patients with atrial fibrillation and/or pulmonary hypertension (n = 44) and patients without MR-related complications (n = 81). Results: For the patients, 10-year overall and cardiovascular survival was 82 ± 4% and 90 ± 3%. At 10 years, patients without preoperative MR-related complications had significantly better overall survival than patients with preoperative LV dysfunction and/or dilatation (89 ± 4% vs 57 ± 13%, log rank p = 0.001). Patients without preoperative MR-related complications also tended to have a better 10-year overall and cardiovascular survival than patients with atrial fibrillation and/or pulmonary hypertension (overall survival of 79 ± 8%), although this did not reach statistical significance (log rank p = 0.17). Cox regression analysis identified the baseline left ventricular ejection fraction and age as the sole independent predictors of outcome. Conclusion: Our data indicate that in asymptomatic patients with severe degenerative MR, mitral valve repair is associated with an excellent long-term prognosis. Nonetheless, the presence of preoperative MR-related complications, in particular LV dysfunction and/or dilatation, greatly attenuates the benefits of surgery. This suggests that mitral valve repair should be performed early, before any MR-related complications ensue.     

Le système nerveux sympathique est un médiateur des contraintes mécaniques dans le tissu osseuxSympathetic nervous system as transmitter of mechanical loading in bone

Sympathetic innervation has been demonstrated in bone. Adrenergic stimulation is one of the transmitters of bone loss by uncoupling between decreased bone formation and increased bone resorption.Objective. – By using a non specific antagonist of β-adrenergic pathway (propranolol per os), we hypothesized that we could rescue the uncoupling induced mechanical unloading bone loss in the rat model of tail-suspension.Materials and methods. – Twenty-two female rats Wistar, 12 week-old, have been divided into three groups: eight tail-suspended rats (SR), six tail-suspended rats treated by propranolol (SRP) and eight non suspended rats (NSR) during 30 days. Bone mineral density (BMD, g/cm²) has been measured by DXA (Hologic QDR-4500A) at D0 and D30 of the study, in the distal femoral metaphysis (DFM), the femoral diaphysis (FD), the whole body (WB, g) and body composition.Results. – Between D0 and D30, in DFM a significant variation in BMD is observed between NSR and SR (% BMD change: NSR +15.6 ± 3.1% vs. SR –1.0 ± 1.4%, P < 0.0001) and BMD rescue in SRP group (% BMD change SRP +5.3 ± 1.5% vs. SR –1.0 ± 1.4%, P = 0.03). In FD, gain of BMD is significant in NSR compared to SR (+17.5 ± 1.5% vs. +8.2 ± 2.8%, P = 0.007), and to SRP (+17.5 ± 1.5% vs + 10.1 ± 2.4%, P = 0.046). Gain in SRP group is not significant compared to SR group (P = 0.6). In WB SRP gain more BMD than NSR (+14.0 ± 1.8% vs. +5.4 ± 0.7%, P = 0.0002) and than SR (+14.0 ± 1.8% vs. +7.8 ± 1.4%, P = 0.0043). There is no difference between NSR and SR groups (P = 0.19).Conclusion. – We demonstrate that β-adrenergic pathway of sympathetic nervous system is a major transmitter pathway of mechanical loading in rat bone. A specific study is necessary to analyse a possible systemic effect of propranolol in rat bone. Propranolol could be used to prevent induced mechanical unloading bone loss as weightlessness.     

Impact of donor quality on outcome of heart transplantation

Objective: Over the last few years, there have been changes in both donor and recipient profiles in heart transplantation. Encouraging clinical outcome of marginal donors in candidates older than 60 years of age led us to allocate suboptimal donors for younger recipients as well. We reviewed our experience retrospectively so as to assess the impact of donor quality on heart transplantation. Methods: Among 181 patients who underwent heart transplantation between January 2000 and February 2009, there were 75 patients (41%) aged 61–70 years and 106 patients (59%) ranging in age between 18 and 60 years. According to the recipient's age, they were classified into four groups. The younger recipients (106 patients) had either optimal donors (70 patients, group 1) or marginal donors (36 patients, group 2). The older recipients (75 patients) had either marginal grafts (64 patients, group 3) or optimal grafts (11 patients, group 4). Sex distribution, cause of end-stage heart failure, preoperative pulmonary hypertension, pre-heart-transplantation clinical status or mean follow-up duration did not show any statistically significant difference among the four groups. Results: Overall, the 9-year actuarial survival rate was 78% ± 1%. The 30 days and 9-year actuarial survival rates were 94% ± 2% and 80% ± 1% in group 1; 86% ± 5% and 55% ± 12% in group 2; 90% ± 4% and 73% ± 7% in group 3; 99% ± 1% and 82% ± 7% in group 4 (P = 0.07). Comparison among the four groups did not show any statistical difference in terms of freedom from graft failure (P = 0.3), right ventricular failure (P = 0.3), acute rejection (P = 0.2), chronic rejection (P = 0.2), neoplasia (P = 0.5) and chronic renal failure (P = 0.2). Older recipients of marginal donors (group 3) had slightly higher prevalence of permanent pacemaker implants: eight permanent pacemakers versus two in group 2, and none in group 1 and group 4 (P = 0.4). Conclusions: Our results suggest that extended donor acceptance criteria may not compromise clinical outcome after heart transplantation. Further follow-up is warranted.