16S rDNA PCR for the aetiological diagnosis of culture-negative infective endocarditis.

INTRODUCTION: Culture-negative infective endocarditis (IE) accounts for 7-31% of all cases. Metagenomics has contributed to improving the aetiological diagnosis of IE patients undergoing valve surgery. We assessed the impact of 16S ribosomal DNA gene polymerase chain reaction (16S rDNA PCR) in the aetiological diagnosis of culture-negative IE. METHODS: Between January 2016 and January 2020, clinical data from culture-negative IE patients were reviewed retrospectively. Identification of bacteria was performed using 16S rDNA PCR in heart valve specimens. RESULTS: 36 out of 313 patients (12%) with culture-negative IE had their valve tissue specimens submitted for 16S rDNA PCR. 16S rDNA PCR detected and identified bacterial nucleic acid in heart valve tissue significantly more frequently compared to valve culture alone 25(70%) vs 5(12%); p < 0.05. Mean age was 57 years (SD 18) and 80% were male. Native and aortic valve were involved in 76% and 52% of cases, respectively. Streptococcus spp. (n 15) were the most commonly detected organisms, followed by bacteria of the HACEK group (Haemophilus parainfluenzae 2, Aggregatibacter actinomycetemcomitans 1), nutritionally variant streptococci (Abiotrophia defectiva 2), and one each of Staphylococcus aureus, Corynebacterium pseudodiphtheriticum, Helcococcus kunzii, Neisseria gonorrhoeae, Tropheryma whipplei. CONCLUSION: 16S rDNA PCR may be a useful diagnostic tool for the identification of the causative organism in culture-negative IE. Efforts towards a shorter turnaround time for results should be consider and further studies assessing the clinical impact of this technique in culture-negative IE are needed.

The impact of complete versus partial preservation of the sub-valvular apparatus on left ventricular function in mitral valve replacement.

INTRODUCTION: In mitral valve replacement (MVR), sudden increases in afterload and disruption of the annular-chordal-papillary-left-ventricular wall causes left ventricular (LV) dysfunction in the early postoperative period. Preservation of the posterior mitral leaflet apparatus (MVR-P) has a favorable outcome on LV function. However, there is paucity of data on the impact of complete preservation of the sub-valvular apparatus (MVR-C). OBJECTIVE: We investigated the impact of MVR-P and MVR-C on baseline and 3-months postoperative LV ejection fraction (EF) and global longitudinal strain (GLS). METHODS: We retrospectively analyzed a cohort of 29 MVR-P and 19 MVR-C patients with complete echocardiography data at our unit, who were operated between 2008 and 2017. Between-group changes in LVEF and GLS were compared using independent sample T-test. RESULTS: Median age was 59 years (IQR 50-69 years). Baseline LVEF was 58% (51%- 60%). Baseline GLS was -18.4 (-21.2 to -15.5). There were no significant between-group differences between all baseline demographics and echocardiographic markers. There was significantly higher absolute postoperative LVEF in MVR-C patients (p = 0.029). There was also significant worsening in LVEF (p = 0.0121) and GLS (p < 0.0001) after MVR-P and not MVR-C, suggesting no reduction in LV function post-MVR-C but a reduction post-MVR-P. There was significantly less postoperative worsening of GLS per patient in MVR-C group as compared to the MVR-P group (p = 0.023), indicating better preservation of LV function. There was also a smaller decline in LVEF per patient in the MVR-C as compared to the MVR-P group, although not statistically significant (p = 0.23). CONCLUSION: MVR with complete preservation of the sub-valvular apparatus shows a favorable impact on the longitudinal function of the heart at 3 months. Further studies with larger patient numbers are indicated to investigate the long-term results of this surgical approach.

Acute aortic dissection type A: Impact of aortic specialists on short and long term outcomes.

OBJECTIVES: Acute aortic dissection type-A (AADA) is a life threatening condition which requires emergency surgery. Surgery is usually performed by cardiac surgeons with various levels of aortic surgical experience. We compared the short-term perioperative outcome and long-term survival of patients operated by specialist aortic surgeons (SASs)and those who were operated by surgeons without specialist expertise. METHODS: A single center retrospective review of 232 patients who underwent acute surgery for AADA was conducted between 2005 and 2020. The cohort was divided into those operated on by SASs (Group A, n = 186) and those operated on by nonaortic surgeons (Group B, n = 46). Statistical comparison was done using regression modelling and groups were propensity matched. Kaplan-Meier comparison was undertaken using STATA14. RESULTS: Of 232 patients, 186 were operated on by an aortic specialist and 46 were operated by a nonaortic specialist. Overall 30-day mortality was 10% in Group A compared to 26.0% in Group B (unadjusted: p = .01, multivariate: p = .02, and propensity matched p = .05). Long-term mortality at 14 years was 26% in Group A compared to 52.0% in Group B (unadjusted: p = .001, multivariate: p = .001, and propensity matched: p = .01). Aortic surgeons performed a significantly higher number of aortic root procedures (43.0% vs. 17.3%, p = .001). The cross-clamp time and bypass time was significantly shorter in Group A patients (89 vs. 105 min, p < .01 and 153 vs. 185, p = < .001). Postoperative requirement for renal filtration was (19% vs. 37%, unadjusted p = .01, multivariate p = .03 and propensity matched p = .04). Although postoperative bleeding was less in Group A (4.0% vs. 11.0%, unadjusted p = .05) after propensity matching it was not statistically significant. CONCLUSIONS: In patients with AADA, surgery performed by aortic specialist's results in improved outcomes. Aortic specialists replaced more of dissected aorta, resulting in an increased number of complex procedures, which may explain improved long-term survival after AADA in this cohort. This study adds further support in establishing a specialist aortic surgical service in cardiac centers.

Pulmonary valve papillary fibroelastoma.

We present a case of a 70-year-old woman with exertional shortness of breath. A transthoracic echocardiogram showed a large mass on the ventricular side of the pulmonary valve. The anatomy of the mass was additionally investigated with a transesophageal echocardiogram, which delineated the anatomical details of the structure. The mass was surgically excised, and histopathology confirmed a cardiac papillary fibroelastoma.

Clinical and hemodynamic outcomes of the Perceval sutureless aortic valve from a real-world registry.

OBJECTIVES: Perceval sutureless valve has been in clinical use for >15 years. The aim of this study is to report the real-word clinical and haemodynamic performance from the SURE-aortic valve replacement international prospective registry in patients who underwent aortic valve replacement with Perceval valve. METHODS: From 2011 to 2021, patients from 55 institutions received a Perceval valve. Postoperative, follow-up, and echocardiographic outcomes were analysed. RESULTS: A total of 1652 patients were included; mean age was 75.3 ± 7.0 years (53.9% female); mean EuroSCORE II was 4.1 ± 6.3. Minimally invasive approach was performed in 45.3% of patients; concomitant procedures were done in 35.9% of cases. Within 30 days, 0.3 and 0.7% valve-related reinterventions were reported. Transient ischaemic attack, disabling and non-disabling strokes were limited (0.4%, 0.4% and 0.7%, respectively). Pacemaker implant was required in 5.7% of patients. Intra-prosthetic regurgitation ≥2 was present in 0.2% of cases, while paravalvular leak ≥2 in only 0.1%. At a maximum follow-up of 8 years, 1.9% of cardiovascular deaths and 0.8% of valve-related reintervention occurred. Among the 10 cases of structural valve deterioration (mean 5.6 ± 1.4 years after implant; range: 2.6-7.3 years), 9 were treated with a transcatheter vale-in-valve implantation and 1 with explant. Mean pressure gradient decreased from 45.8 ± 16.5 mmHg preoperatively to 13.3 ± 5.2 mmHg at discharge and remained stable during follow-up. CONCLUSIONS: This experience represents the largest prospective real-world cohort of patients treated with Perceval showing that Perceval is a safe and effective alternative to conventional surgical aortic valve replacement, providing favourable clinical and haemodynamic results also at mid-term follow-up.

Three-dimensional printing in modelling mitral valve interventions.

Mitral interventions remain technically challenging owing to the anatomical complexity and heterogeneity of mitral pathologies. As such, multi-disciplinary pre-procedural planning assisted by advanced cardiac imaging is pivotal to successful outcomes. Modern imaging techniques offer accurate 3D renderings of cardiac anatomy; however, users are required to derive a spatial understanding of complex mitral pathologies from a 2D projection thus generating an 'imaging gap' which limits procedural planning. Physical mitral modelling using 3D printing has the potential to bridge this gap and is increasingly being employed in conjunction with other transformative technologies to assess feasibility of intervention, direct prosthesis choice and avoid complications. Such platforms have also shown value in training and patient education. Despite important limitations, the pace of innovation and synergistic integration with other technologies is likely to ensure that 3D printing assumes a central role in the journey towards delivering personalised care for patients undergoing mitral valve interventions.

Should more patients be offered repair for mitral valve endocarditis? a single-centre 15-year experience.

OBJECTIVE: To describe the long-term outcomes of mitral valve repair (MVr) versus mitral valve replacement (MVR) in patients with native valve infective endocarditis (IE) at a centre with high-repair rates. METHODS: We conducted a retrospective single-centre cohort study. From 2005 to 2021, 183 patients with active or healed native valve IE were included. The primary outcome was long-term mortality. Patient status was last confirmed 31 March 2021. Secondary outcomes were post-operative MR, MV reoperation, length of post-operative intensive care stay and total hospital stay. RESULTS: 85 patients (46.4%) underwent MVr and 98 (53.6%) underwent MVR. Follow-up was 98.9% complete. Mean follow-up time was 5.3 years with 17% of patients reaching a follow-up time of over 10 years. There were 47 deaths (25.7%) within the follow-up period. MVR patients were more likely to have higher logistic EuroSCORE, active IE and were less likely to have elective surgery. In multivariate Cox proportional hazards analysis, there was no significant difference in long-term mortality between MVr and MVR groups (hazard ratio 1.09, 95% confidence interval [0.59-2.00]). In Kaplan-Meier analysis, MVR patients had a higher all-cause mortality although there was no significant difference at the endpoint. Propensity score matching analysis showed a significantly higher mortality in the replacement group instead (p = 0.002), Subgroup analysis revealed there remained no significant difference in mortality even in patients with active IE (P-interaction = 0.859) or non-elective surgery (P-interaction = 0.122). MV reoperation (odds ratio 1.00 [0.24-4.12]), post-operative intensive care stay (p = 0.9650) and total hospital stay (p = 0.9144) were comparable. CONCLUSIONS: Our data demonstrates repair was at least non-inferior to replacement in IE, supporting more aggressive use of repair. There is no reason the general principle of why repair is superior to replacement should not hold in IE, with enough operator expertise. Other experienced units should be encouraged to increase repair rates as feasible in line with current guidelines.

Diagnostic value of 18F-FDG PET/CT in infective endocarditis.

INTRODUCTION: 18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET/CT) is not routinely recommended for the diagnosis of infective endocarditis (IE) due to the lack of clinical impact. MATERIALS AND METHODS: Between January 2016 and January 2020, clinical data from patients with a possible diagnosis of IE were reviewed retrospectively to evaluate the value of 18F-FDG-PET/CT in the diagnosis of IE. 18F-FDG PET/CT scan was performed as an additional diagnostic tool in possible IE when echocardiography was inconclusive or in patients with definite IE to identify extracardiac complications. Cases were classified according to modified Duke criteria as rejected, definite or possible. RESULTS: 313 patients with suspected IE were included. 72 (23%) patients underwent 18F-FDG PET/CT. 18F-FDG PET/CT resulted in a reclassification of Duke criteria in 29/72 (40%) patients, from "possible" to "definite" (n, 10) and to "rejected" (n, 19). Patients who benefited from a Duke criteria reclassification following 18F-FDG PET/CT were more frequently classified as possible IE at inclusion or had a non-conclusive baseline echocardiography (100% vs 58%; p 0.001) and had more likely a prosthetic metallic valve replacement (59% vs 21%; p 0.001). Abnormal perivalvular uptake was identified in 46 patients (71% prosthetic vs 50% native; p 0.118). 18F-FDG PET/CT identified extracardiac uptake consistent with septic emboli in 14/72 (19%) patients. In addition, extracardiac uptake indicative of an alternative diagnosis was identified in 5 patients (2% prosthetic vs 17% native; p 0.039). CONCLUSION: The use of 18F-FDG-PET/CT has shown to be useful in the diagnosis of IE, particularly in prosthetic IE and may provide additional value in the detection of septic emboli and/or the identification of an alternative diagnosis different from IE.

Aortic valve surgery in the UK, trends in activity and outcomes from a 15-year complete national series.

OBJECTIVES: Since the turn of the century, cardiac surgery has evolved quite notably. This study sought to investigate the trends in aortic valve surgery activity and subsequent outcomes in the UK by using a mandatory national cardiac surgical clinical database within the context of a comprehensive public healthcare system (National Health Service). METHODS: The UK National Adult Cardiac Surgery Audit database provided data for aortic valve surgery procedures performed between 2002 and 2016, and the data were validated and cleaned using reproducible algorithms. The findings and trends in in activity and outcomes were then analysed by financial year. RESULTS: During the study period, a total of 148 862 procedures were performed, with the number of cases per year peaking in 2014/2015 at 12 483. The mean in-hospital mortality rate for all aortic valve surgery has fallen from 5.6% to 3.4%, despite an increase in patient age and mean logistic EuroSCORE. While the number of isolated aortic valve replacements has remained stable at around 5000 per year, aortic valve replacement and coronary artery bypass graft have increased to over 3200 with transcatheter aortic valve implantation activity continuing to increase. CONCLUSIONS: This study demonstrates that despite an increase in patient risk profile, there has been a consistent reduction in in-hospital mortality within all aortic valve surgery procedures performed in the UK over a 15-year period. Increasing catheter-based interventions have not yet resulted in a significant decrease in surgical aortic valve replacements in the UK.

Sutureless Valve in Repeated Aortic Valve Replacement: Results from an International Prospective Registry.

OBJECTIVE: To report early and midterm results registry of patients undergoing repeated aortic valve replacement (RAVR) with sutureless prostheses from an international prospective registry (SURE-AVR). METHODS: Between March 2011 and June 2019, 69 patients underwent RAVR with self-expandable sutureless aortic bioprostheses at 22 international cardiac centers. RESULTS: Overall mortality was 2.9% with a predicted logistic EuroSCORE II of 10.7%. Indications for RAVR were structural valve dysfunction (84.1%) and infective prosthetic endocarditis (15.9%) and were performed in patients with previously implanted bioprostheses (79.7%), mechanical valves (15.9%), and transcatheter valves (4.3%). Minimally invasive approach was performed in 15.9% of patients. Rate of stroke was 1.4% and rate of early valve-related reintervention was 1.4%. Overall survival rate at 1 and 5 years was 97% and 91%, respectively. No major paravalvular leak occurred. Rate of pacemaker implantation was 5.8% and 0.9% per patient-year early and at follow-up, respectively. The mean transvalvular gradient at 1-year and 5-year follow-up was 10.5 mm Hg and 11.5 mm Hg with a median effective orifice area of 1.8 cm2and 1.8 cm2, respectively. CONCLUSIONS: RAVR with sutureless valves is a safe and effective approach and provides excellent clinical and hemodynamic results up to 5 years.

Clinical outcomes after implantation of a sutureless aortic bioprosthesis with concomitant mitral valve surgery: the SURE-AVR registry.

BACKGROUND: Early treatment of aortic valve stenosis is recommended in eligible symptomatic patients with severe aortic valve stenosis who would otherwise have a poor prognosis. The sutureless aortic valve bioprosthesis offers an alternative to standard aortic valve replacement with a sutured valve, but limited data are available in patients who have undergone multiple valve procedures involving the new, sutureless technology. We sought to investigate outcomes in high operative risk patients with previous or concomitant valve surgery who were implanted with a sutureless valve. METHODS: SURE-AVR is an ongoing, prospective, multinational registry of patients undergoing aortic valve replacement. In-hospital and post-discharge outcomes up to 5 years were collected. RESULTS: The study population comprised 78 patients (mean ± SD: age 73.6 ± 7.6 years, logistic EuroSCORE 18.0 ± 17.5) enrolled at 13 sites who presented for concomitant or previous mitral valve repair (n = 45) or replacement (n = 33), with or without additional concomitant procedures, and were implanted with a sutureless valve. Mean ± SD overall aortic cross-clamp time was 109 ± 41 min and cardiopulmonary bypass time was 152 ± 49 min. Mean ± SD aortic pressure gradients decreased from 37.6 ± 17.7 mmHg preoperatively to 13.0 ± 5.7 mmHg at hospital discharge, and peak aortic pressure gradient from 61.5 ± 28.7 to 23.4 ± 10.6 mmHg. Early events included 1 death, 1 transient ischaemic attack, and 1 bleed (all 1.3%); a permanent pacemaker implantation was required in 6 patients (7.7%), and 2 reoperations (not valve related) (2.6%) took place. Over a median follow-up of 55.5 months (Q1 13.4, Q3 68.6), 12 patients died (6 cardiovascular and 6 non-cardiovascular, both 2.1% per patient-year). Five-year survival was 81.3%. Late paravalvular leak occurred in 2 patients (0.7% per patient-year) and permanent pacemaker implantation was required in 3 patients (0.1% per patient-year). There was no apparent rise in mean or peak aortic pressure gradient over the study. CONCLUSIONS: These results suggest that the sutureless implant is a technically feasible procedure during mitral surgery and is associated with good clinical outcomes.

Surgical aortic valve replacement in the era of transcatheter aortic valve implantation: a review of the UK national database.

OBJECTIVES: To date the reported outcomes of surgical aortic valve replacement (SAVR) are mainly in the settings of trials comparing it with evolving transcatheter aortic valve implantation. We set out to examine characteristics and outcomes in people who underwent SAVR reflecting a national cohort and therefore 'real-world' practice. DESIGN: Retrospective analysis of prospectively collected data of consecutive people who underwent SAVR with or without coronary artery bypass graft (CABG) surgery between April 2013 and March 2018 in the UK. This included elective, urgent and emergency operations. Participants' demographics, preoperative risk factors, operative data, in-hospital mortality, postoperative complications and effect of the addition of CABG to SAVR were analysed. SETTING: 27 (90%) tertiary cardiac surgical centres in the UK submitted their data for analysis. PARTICIPANTS: 31 277 people with AVR were identified. 19 670 (62.9%) had only SAVR and 11 607 (37.1%) had AVR+CABG. RESULTS: In-hospital mortality for isolated SAVR was 1.9% (95% CI 1.6% to 2.1%) and was 2.4% for AVR+CABG. Mortality by age category for SAVR only were: <60 years=2.0%, 60-75 years=1.5%, >75 years=2.2%. For SAVR+CABG these were; 2.2%, 1.8% and 3.1%. For different categories of EuroSCORE, mortality for SAVR in low risk people was 1.3%, in intermediate risk 1% and for high risk 3.9%. 74.3% of the operations were elective, 24% urgent and 1.7% emergency/salvage. The incidences of resternotomy for bleeding and stroke were 3.9% and 1.1%, respectively. Multivariable analyses provided no evidence that concomitant CABG influenced outcome. However, urgency of the operation, poor ventricular function, higher EuroSCORE and longer cross clamp and cardiopulmonary bypass times adversely affected outcomes. CONCLUSIONS: Surgical SAVR±CABG has low mortality risk and a low level of complications in the UK in people of all ages and risk factors. These results should inform consideration of treatment options in people with aortic valve disease.

Minimally invasive versus conventional sternotomy for Mitral valve repair: protocol for a multicentre randomised controlled trial (UK Mini Mitral).

INTRODUCTION: Numbers of patients undergoing mitral valve repair (MVr) surgery for severe mitral regurgitation have grown and will continue to rise. MVr is routinely performed via median sternotomy; however, there is a move towards less invasive surgical approaches.There is debate within the clinical and National Health Service (NHS) commissioning community about widespread adoption of minimally invasive MVr surgery in the absence of robust research evidence; implementation requires investment in staff and infrastructure.The UK Mini Mitral trial will provide definitive evidence comparing patient, NHS and clinical outcomes in adult patients undergoing MVr surgery. It will establish the best surgical approach for MVr, setting a standard against which emerging percutaneous techniques can be measured. Findings will inform optimisation of cost-effective practice. METHODS AND ANALYSIS: UK Mini Mitral is a multicentre, expertise based randomised controlled trial of minimally invasive thoracoscopically guided right minithoracotomy versus conventional sternotomy for MVr. The trial is taking place in NHS cardiothoracic centres in the UK with established minimally invasive mitral valve surgery programmes. In each centre, consenting and eligible patients are randomised to receive surgery performed by consultant surgeons who meet protocol-defined surgical expertise criteria. Patients are followed for 1 year, and consent to longer term follow-up.Primary outcome is physical functioning 12 weeks following surgery, measured by change in Short Form Health Survey (SF-36v2) physical functioning scale. Early and 1 year echo data will be reported by a core laboratory. Estimates of key clinical and health economic outcomes will be reported up to 5 years.The primary economic outcome is cost effectiveness, measured as incremental cost per quality-adjusted life year gained over 52 weeks following index surgery. ETHICS AND DISSEMINATION: A favourable opinion was given by Wales REC 6 (16/WA/0156). Trial findings will be disseminated to patients, clinicians, commissioning groups and through peer reviewed publication. TRIAL REGISTRATION NUMBER: ISRCTN13930454.

Management of pneumothorax in mechanically ventilated COVID-19 patients: early experience.

A significant proportion of patients infected with the novel coronavirus, now termed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), require intensive care admission and subsequent mechanical ventilation. Pneumothorax, a potential fatal complication of mechanical ventilation, can further complicate the management of COVID-19 patients, whilst chest drain insertion may increase the risk of transmission of attending staff. We present a case series and a suggested best-practice protocol for how to manage and treat pneumothoraces in COVID-19 patients in an intensive care unit setting.

Minimally Invasive Aortic Valve Replacement with Sutureless Valves: Results From an International Prospective Registry.

OBJECTIVE: To report the early and mid-term results of patients who underwent minimally invasive aortic valve replacement (MI-AVR) with a sutureless prosthesis from an international prospective registry. METHODS: Between March 2011 and September 2018, among 957 patients included in the prospective observational SURE-AVR (Sorin Universal REgistry on Aortic Valve Replacement) registry, 480 patients underwent MI-AVR with self-expandable Perceval aortic bioprosthesis (LivaNova PLC, London, UK) in 29 international institutions through either minithoracotomy (n = 266) or ministernotomy (n = 214). Postoperative, follow-up, and echocardiographic outcomes were analyzed for all patients. RESULTS: Patient age was 76.1 ± 7.1 years; 64.4% were female. Median EuroSCORE I was 7.9% (interquartile range [IQR], 4.8 to 10.9). Median cardiopulmonary bypass and cross-clamp times were 81 minutes (IQR 64 to 100) and 51 minutes (IQR 40 to 63). First successful implantation was achieved in 97.9% of cases. Two in-hospital deaths occurred, 1 for noncardiovascular causes and 1 following a disabling stroke. In the early (≤30 days) period, stroke rate was 1.4%. Three early explants were reported: 2 due to nonstructural valve dysfunction (NSVD) and 1 for malpositioning. One mild and 1 moderate paravalvular leak were reported. In 16 patients (3.3%) pacemaker implantation was needed. Mean follow-up was 2.4 years (maximum = 7 years). During follow-up 5 explants were reported, 3 due to endocarditis and 2 due to NSVD. Follow-up stroke rate was 2.5%. Three structural valve deteriorations not requiring reintervention were reported. Five-year survival was 91.45%. CONCLUSIONS: In this large prospective international registry, MI-AVR with Perceval valve confirmed to be safe, reproducible, and effective in an intermediate-risk population, providing excellent clinical recovery both in early and mid-term follow-up.

BISMICS consensus statement: implementing a safe minimally invasive mitral programme in the UK healthcare setting.

Disseminating the practice of minimally invasive mitral surgery (mini-MVS) can be challenging, despite its original case reports a few decades ago. The penetration of this technology into clinical practice has been limited to centres of excellence, and mitral surgery in most general cardiothoracic centres remains to be conducted via sternotomy access as a first line. The process for the uptake of mini-MVS requires clearer guidance and standardisation for the processes involved in its implementation. In this statement, a consensus agreement is outlined that describes the benefits of mini-MVS, including reduced postoperative bleeding, reduced wound infection, enhanced recovery and patient satisfaction. Technical considerations require specific attention and can be introduced through simulation and/or use in conventional cases. Either endoballoon or aortic cross clamping is recommended, as well as femoral or central aortic cannulation, with the use of appropriate adjuncts and instruments. A coordinated team-based approach that encourages ownership of the programme by the team members is critical. A designated proctor is also recommended. The organisation of structured training and simulation, as well as planning the initial cases, is an important step to consider. The importance of pre-empting complications and dealing with adverse events is described, including re-exploration, conversion to sternotomy, unilateral pulmonary oedema and phrenic nerve injury. Accounting for both institutional and team considerations can effectively facilitate the introduction of a mini-MVS service. This involves simulation, team-based training, visits to specialist centres and involvement of a designated proctor to oversee the initial cases.

Calculated plasma volume status and outcomes in patients undergoing coronary bypass graft surgery.

OBJECTIVES: Congestion is associated with worse outcomes in critically ill surgical patients but can be difficult to quantify noninvasively. We hypothesised that plasma volume status (PVS), estimated preoperatively using a validated formula that enumerates percentage change from ideal plasma volume (PV), would provide incremental prognostic utility after coronary artery bypass graft (CABG) surgery. METHODS: In this retrospective cohort study, patients who underwent CABG surgery (1999-2010) were identified from a prospectively collected database. Actual ([1-haematocrit] x [a+(b x weight [kg])]) and ideal (c x weight [kg]) PV were obtained from equations where a, b and c are sex-dependent constants. Calculated PVS was then derived (100% x [(actual-ideal)/ideal]). RESULTS: In 1887 patients (mean age 67±10 years; 79% male; median European System for Cardiac Operative Risk Evaluation [EuroSCORE] 4), mean PVS was -8.2±9%. While 8% of subjects had clinical evidence of congestion, a relatively increased PV (PVS >0%) was estimated in 17% and correlated with lower serum sodium, higher EuroSCORE and a diagnosis of diabetes mellitus. A PVS≥5.6% was optimally prognostic and associated with greater mortality (HR: 2.31, p=0.009), independently of, and incremental to, EuroSCORE, New York Heart Association class and serum sodium. A PVS≥5.6% also independently predicted longer intensive care (ß: 0.65, p=0.007) and hospital (ß: 2.01, p=0.006) stays, and greater postoperative renal (OR: 1.61, p=0.008) and arrhythmic (OR: 1.29, p=0.03) complications. CONCLUSIONS: Higher PVS values, calculated simply from weight and haematocrit, are associated with worse inpatient outcomes after CABG. PVS could help refine risk stratification and further investigations are warranted to evaluate the potential clinical utility of PVS-guided management in patients undergoing CABG.

Silzone-coated St. Jude Medical valves: six-year experience in 46 patients.

BACKGROUND AND AIM OF THE STUDY: The Silzone-coated St. Jude Medical valve was developed to reduce prosthetic valve endocarditis, but in the Artificial Valve Endocarditis Trial (AVERT) was recalled following reports of major paravalvular leaks. A separate study suggested an increased risk of thromboembolic complications associated with the Silzone valve. Herein is reviewed the present authors' experience in patients with Silzone valves. METHODS: Between April 1998 and November 1999, 46 patients (28 males, 18 females; mean age 62.6 years; range: 41-78 years) received a total of 49 Silzone valves. Seven of the patients were in NYHA class IV, and 29 in class III; four patients had active endocarditis. Twenty-one patients underwent aortic valve replacement, 22 mitral valve replacement, and three had both mitral and aortic valve replacement. Concomitant procedures were performed in nine patients. RESULTS: The 30-day mortality was 6.5 % (n = 3). At post-mortem examination, the valves were found to be seated well, with no evidence of malfunction, thrombotic occlusion or infection. Follow up examinations were conducted initially at six months after surgery, and annually thereafter. All patients underwent transthoracic echocardiography. Follow up was 100% complete; the mean follow up period was 73.5 months (range: 62-81 months). Six late deaths have occurred; five deaths were due to non-cardiac causes, and one cardiac death was unrelated to the valve prosthesis. No cases of paravalvular leak have been identified. Two patients had postoperative thromboembolic complications, but echocardiography did not demonstrate the presence of thrombus or paravalvular leakage. CONCLUSION: In this single-center, non-randomized study of 46 patients, the findings of increased paravalvular leak with the Silzone valve, as identified in AVERT study, could not be confirmed. Moreover, the incidence of thromboembolic complications reported was modest.

FCCP is cardioprotective at concentrations that cause mitochondrial oxidation without detectable depolarisation.

OBJECTIVE: The role of mitochondria and in particular of mitochondrial uncoupling in the mechanism of cardioprotection is not defined. In the accompanying paper we have shown that pretreatment of isolated rat hearts with a low concentration (100 nM) of FCCP, prior to global ischaemia, is cardioprotective, while 300 nM FCCP exacerbates injury. Here we define the mitochondrial responses to increasing concentrations of FCCP and also to explore the equivalence of the cardioprotective doses of diazoxide. METHODS: Changes in mitochondrial respiration in response to FCCP and diazoxide were determined in isolated rat ventricular myocytes. In addition, mitochondrial state was monitored using confocal microscopy to record mitochondrial potential (TMRM) and redox state (NADH) during FCCP and diazoxide treatment. Myocytes were also voltage-clamped and whole cell currents recorded in response to 100 nM FCCP. RESULTS: FCCP (10-1000 nM) caused significant dose-dependent increase in oxygen consumption. Diazoxide (30 microM) failed to cause any measurable change in mitochondrial function. FCCP at 100 nM caused mitochondrial oxidation, but no change in mitochondrial membrane potential or (sarc)K(ATP) channel current, while at 300 nM, FCCP caused significant mitochondrial depolarisation. Diazoxide failed to induce any mitochondrial oxidation or depolarisation. CONCLUSIONS: Concentrations of FCCP that cause mitochondrial oxidation without depolarisation are cardioprotective. Higher FCCP concentrations dissipate mitochondrial membrane potential and exacerbate injury. This establishes the principle that mild mitochondrial uncoupling activates a protective mechanism. Diazoxide did not cause mitochondrial oxidation or mitochondrial depolarisation, suggesting it induces protection via another mechanism.

Pneumococcal pulmonary valve endocarditis.

Pulmonary valve endocarditis is an rare type of infective endocarditis (IE). Streptococcus pneumoniae is a pathogen that is uncommonly associated with IE. A 50 year-old man was referred to us to an incidental echocardiographic finding of a pulmonary valve vegetation. He had a recent admission for drainage of a scrotal abscess from which streptococcus pneumoniae was isolated, complicated by hospital acquired pneumonia and pulmonary embolism. Analysis using Polymerase Chain Reaction of the surgically resected mass revealed signs of 16S rDNA consistent with Streptococcus pneumoniae infection. This is the first confirmed case of pneumococcal pulmonary valve IE presenting entirely asymptomatically in the absence of any known risk factors.