Michael Seco

Custodiol for myocardial protection and preservation: a systematic review

INTRODUCTION Custodiol cardioplegia is attractive for minimally invasive cardiac surgery, as a single dose provides a long period of myocardial protection. Despite widespread use in Europe, there is little data confirming its efficacy compared with conventional (blood or crystalloid) cardioplegia. There is similar enthusiasm for its use in organ preservation for transplant, but also a lack of data. This systematic review aimed to assess the evidence for the efficacy of Custodiol in myocardial protection and as a preservation solution in heart transplant. METHODS Electronic searches were performed of six databases from inception to October 2013. Reviewers independently identified studies that compared Custodiol with conventional cardioplegia (blood or extracellular crystalloid) in adult patients for meta-analysis; large case series that reported results using Custodiol were analyzed. Next, we identified studies that compared Custodiol with other organ preservation solutions for organ preservation in heart transplant. RESULTS Fourteen studies compared Custodiol with conventional cardioplegia for myocardial protection in adult cardiac surgery. No difference was identified in mortality; there was a trend for increased incidence of ventricular fibrillation in the Custodiol group that did not reach statistical significance. No difference was identified in studies that compared Custodiol with other solutions for heart transplant. CONCLUSIONS Despite widespread clinical use, the evidence supporting the superiority of Custodiol over other solutions for myocardial protection or organ preservation is limited. Large randomised trials are required.

Systematic review of robotic minimally invasive mitral valve surgery

BACKGROUND Robotic telemanipulators have evolved to assist the challenges of minimally invasive mitral valve surgery (MVS). A systematic review was performed to provide a synopsis of the literature, focusing on clinical outcomes and cost-effectiveness. METHOD Structured searches of MEDLINE, Embase, and Cochrane databases were performed in August 2013. All original studies except case-reports were included in qualitative review. Studies with ≥50 patients were presented quantitatively. RESULTS After applying inclusion and exclusion criteria to the search results, 27 studies were included in qualitative review, 16 of which had ≥50 patients. All studies were observational in nature, and thus the quality of evidence was rated low to medium. Patients generally had good left ventricular performance, were relatively asymptomatic, and mean patient age ranged from 52.6-58.4 years. Rates of intraoperative outcomes ranged from: 0.0-9.1% for conversion to non-robotic surgery, 106±22 to 188.5±53.8 min for cardiopulmonary bypass (CPB) time and 79±16 to 140±40 min for cross-clamp (XC) time. Rates of short-term postoperative outcomes ranged from: 0.0-3.0% for mortality, 0.0-3.2% for myocardial infarction (MI), 0.0-3.0% for permanent stroke, 1.6-15% for pleural effusion, 0.0-5.0% for reoperations for bleeding, 0.0-0.3% for infection, and 1.1-6% for prolonged ventilation (>48 hours), 1.5-5.4% for early repair failure, 12.3±6.7 to 36.6±24.7 hours for intensive care length of stay, 3.1±0.3 to 6.3±3.9 days for hospital length of stay (HLOS) and 81.7-97.6% had no or trivial mitral regurgitation (MR) before discharge. CONCLUSIONS All subtypes of mitral valve prolapse are repairable with robotic techniques. CPB and XC times are long, and novel techniques such as the Cor-Knot, Nitinol clips or running sutures may reduce the time required. The overall rates of early postoperative mortality and morbidity are low. Improvements in postoperative quality of life (QoL) and expeditious return to work offset the increase in equipment and intraoperative cost. Evidence for long-term outcomes is as yet limited.

Extracorporeal Membrane Oxygenation for Very High-risk Transcatheter Aortic Valve Implantation

BACKGROUND Transcatheter aortic valve implantation (TAVI) can cause profound haemodynamic perturbation in the peri-operative period. Veno-arterial extracorporeal membrane oxygenation (ECMO) can be used to provide cardiorespiratory support during this time, either prophylactically or emergently. METHOD 100 TAVI procedures were performed between 2009 and 2013 in our institution. ECMO was used in 11 patients, including eight prophylactic and three rescue cases. Rescue ECMO was required for ventricular fibrillation after valvuloplasty, and aortic annulus rupture. The criteria for prophylactic ECMO included heart failure requiring stabilisation pre-TAVI, haemodynamic instability with balloon aortic valvuloplasty performed to improve heart function pre-TAVI, moderate or severe left and/or right ventricular failure, or borderline haemodynamics at procedure. Differences in preoperative characteristics and postoperative outcomes between ECMO and non-ECMO TAVI patients were compared, and significant results were further assessed controlling for EuroSCORE. RESULTS Compared to TAVI patients who did not require ECMO, ECMO patients had significantly higher mean EuroSCORE (51 vs. 30%, p<.05). Postoperative outcomes, however, were largely comparable between the two groups. All-cause mortality occurred in nil prophylactic ECMO patients, one rescue ECMO patient, and two non-ECMO patients. The difference in mortality between ECMO and non-ECMO patients was not significantly different (9 vs. 2%; p>.05). ECMO patients were more likely to develop acute renal failure than non-ECMO patients (36 vs. 8%, p<.05), which was most likely due to haemodynamic collapse and end-organ dysfunction in patients that required ECMO rescue. CONCLUSIONS Instituting prophylactic ECMO in selected very high-risk patients may help avoid consequences of intra-operative complications and the need for emergent rescue ECMO.

Serum Biomarkers of Neurologic Injury in Cardiac Operations

Assessment of subtle neurocognitive decline after surgical procedures has been hampered by heterogeneous testing techniques and a lack of reproducibility. This review summarizes the sensitivity and specificity of biomarkers of neurologic injury to determine whether they can be applied in the postoperative period to accurately predict neurocognitive decline. Creatine kinase-brain type, neuron-specific enolase, and S100B can be released into serum during operations by extracranial sources. Glial fibrillary acidic protein is a sensitive marker, and there are extracranial sources that are antigenically different from the brain-derived form. Serum levels of tau protein after acute neurologic injury do not reliability correlate with incidence.

The silent and apparent neurological injury in transcatheter aortic valve implantation study (SANITY): concept, design and rationale.

BackgroundThe incidence of clinically apparent stroke in transcatheter aortic valve implantation (TAVI) exceeds that of any other procedure performed by interventional cardiologists and, in the index admission, occurs more than twice as frequently with TAVI than with surgical aortic valve replacement (SAVR). However, this represents only a small component of the vast burden of neurological injury that occurs during TAVI, with recent evidence suggesting that many strokes are clinically silent or only subtly apparent. Additionally, insult may manifest as slight neurocognitive dysfunction rather than overt neurological deficits. Characterisation of the incidence and underlying aetiology of these neurological events may lead to identification of currently unrecognised neuroprotective strategies.MethodsThe Silent and Apparent Neurological Injury in TAVI (SANITY) Study is a prospective, multicentre, observational study comparing the incidence of neurological injury after TAVI versus SAVR. It introduces an intensive, standardised, formal neurologic and neurocognitive disease assessment for all aortic valve recipients, regardless of intervention (SAVR, TAVI), valve-type (bioprosthetic, Edwards SAPIEN-XT) or access route (sternotomy, transfemoral, transapical or transaortic). Comprehensive monitoring of neurological insult will also be recorded to more fully define and compare the neurological burden of the procedures and identify targets for harm minimisation strategies.DiscussionThe SANITY study undertakes the most rigorous assessment of neurological injury reported in the literature to date. It attempts to accurately characterise the insult and sustained injury associated with both TAVI and SAVR in an attempt to advance understanding of this complication and associations thus allowing for improved patient selection and procedural modification.

Systematic review of robotic-assisted, totally endoscopic coronary artery bypass grafting

BACKGROUND Advancements in surgical robotic technology over the last two decades have enabled coronary artery bypass grafting to be performed totally endoscopically, and have the potential to significantly change clinical practice in the future. METHODS A systematic review of studies reporting clinical outcomes of total endoscopic coronary artery bypass grafting (TECABG) was performed. RESULTS 14 appraised studies included 880 beating heart TECABGs, 360 arrested heart TECABGs, 633 one-vessel operations and 357 two-vessel operations. Patients were generally low-risk. There was a significant learning curve. The weighted means for short-term beating heart and arrested heart TECABG results respectively were: intraoperative exclusion rate of 5.7% and 1.9%, intraoperative conversion rate of 5.6% and 15.0%, all-cause mortality of 1.2% and 0.4%, stroke of 0.7% and 0.8%, myocardial infarction of 0.8% and 1.8%, new onset atrial fibrillation of 10.7% and 5.1% and post-operative reintervention rate of 2.6% and 2.3%. The overall rate of short term postoperative graft patency for beating heart and arrested heart TECABG was 98.3% and 96.4% respectively. CONCLUSIONS Appropriate patient selection was important in minimizing the risk of intraoperative and postoperative complications. Short-term outcomes of both beating and arrested heart TECABG were acceptable, but results so far have been heterogeneous. There were fewer studies reporting intermediate to long-term outcomes, but results were encouraging, and further investigation and development of the procedure is warranted.

Introduction of an interdisciplinary heart team-based transcatheter aortic valve implantation programme: short and mid-term outcomes.

Transcatheter aortic valve implantation (TAVI) has been developed to treat symptomatic aortic stenosis in patients deemed too high risk for open‐heart surgery. To address this complex population, an interdisciplinary heart team approach was proposed.

Transapical Aortic Valve Implantation—An Australian Experience

BACKGROUND The aim of this study was to report our initial experience with the transapical approach to transcatheter aortic valve implantation (TAVI) at an Australian institution. METHODS All patients with severe, symptomatic aortic stenosis were assessed by our multidisciplinary team. A total of 32 patients received a transapical TAVI using an Edwards SAPIEN prosthesis. Data were prospectively collected and analysed according to the Valve Academic Research Consortium version 2 guidelines. RESULTS Intraoperative outcomes included: 100% device success with no conversion to surgical valve replacement, extracorporeal membrane oxygenation was used electively in 15.6% and emergently in 6.3%, and no valve migration or malpositioning requiring prosthesis retrieval and re-implantation. Outcomes at 30 days post-TAVI included: No mortality, 3.1% myocardial infarction, no disabling stroke, 3.1% non-disabling stroke, no transient ischaemic attacks, 6.3% life-threatening bleeding, 15.6% major bleeding, 3.1% major vascular complications, and 12.5% postoperative acute kidney injury requiring renal replacement therapy. Mild paravalvular regurgitation was present in 29%, and there was no moderate or severe regurgitation. Mean follow-up time was 28.8±12.9 months. Cumulative results included: 9.4% mortality, 6.3% stroke, 6.3% myocardial infarction, and no repeat procedures. At one year postoperation, echocardiography demonstrated that the mean pressure across the prosthesis was 10.1±1.7mmHg, and the mean aortic valve area was 1.4±0.2cm(2). CONCLUSION Good short-term outcomes and low or zero mortality are achievable with transapical TAVI at an Australian institution.

Long-term prognosis and cost-effectiveness of left ventricular assist device as bridge to transplantation: a systematic review

BACKGROUND This systematic review aimed to evaluate the clinical outcomes and cost-effectiveness of left ventricular assist devices (LVADs) used as bridge to transplantation (BTT), compared to orthotopic heart transplantation (OHT) without a bridge. METHOD Systematic searches were performed in electronic databases with available data extracted from text and digitized figures. Meta-analysis of short and long-term term post-transplantation outcomes was performed with summation of cost-effectiveness analyses. RESULTS Twenty studies reported clinical outcomes of 4575 patients (1083 LVAD BTT and 3492 OHT). Five studies reported cost-effectiveness data on 837 patients (339 VAD BTT and 498 OHT). There was no difference in long-term post-transplantation survival (HR 1.24, 95% CI 1.00-1.54), acute rejection (HR 1.10, 95% CI 0.93-1.30), or chronic rejection and cardiac allograft vasculopathy (HR 0.99, 95% CI 0.73-1.36). No differences were found in 30-day post-operative mortality (OR 0.91, 95% CI 0.42-2.00), stroke (OR 1.64, 95% CI 0.43-6.27), renal failure (OR 1.43, 95% CI 0.58-3.54), bleeding (OR 1.56, 95% CI 0.78-3.13), or infection (OR 2.44, 95% CI 0.81-7.38). Three of the five studies demonstrated incremental cost-effectiveness ratios below the acceptable maximum threshold. The total cost of VAD BTT ranged from

Neurocognitive and Psychiatric Issues Post Cardiac Surgery

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