Perioperative transfusion and long-term mortality after cardiac surgery: a meta-analysis.

OBJECTIVES: Cardiac surgical procedures are associated with a high incidence of periprocedural blood loss and blood transfusion. Although both may be associated with a range of postoperative complications there is disagreement on the impact of blood transfusion on long-term mortality. This study aims to provide a comprehensive review of the published outcomes of perioperative blood transfusion, examined as a whole and by index procedure. METHODS: A systematic review of perioperative blood transfusion cardiac surgical patients was conducted. Outcomes related to blood transfusion were analysed in a meta-analysis and aggregate survival data were derived to examine long-term survival. RESULTS: Thirty-nine studies with 180,074 patients were identified, the majority (61.2%) undergoing coronary artery bypass surgery. Perioperative blood transfusions were noted in 42.2% of patients and was associated with significantly higher early mortality (OR 3.87, p < 0.001). After a median of 6.4 years (range 1-15), mortality remained significantly higher for those who received a perioperative transfusion (OR 2.01, p < 0.001). Pooled hazard ratio for long-term mortality similar for patients who underwent coronary surgery compared to isolated valve surgery. Differences in long-term mortality for all comers remained true when corrected for early mortality and when only including propensity matched studies. CONCLUSIONS: Perioperative red blood transfusion appears to be associated with a significant reduction in long-term survival for patients after cardiac surgery. Strategies such as preoperative optimisation, intraoperative blood conservation, judicious use of postoperative transfusions, and professional development into minimally invasive techniques should be utilised where appropriate to minimise the need for perioperative transfusions.

Transcatheter Aortic Valve Implantation (TAVI) Versus Surgical Aortic Valve Replacement for Aortic Stenosis (SAVR): A Cost-Comparison Study.

BACKGROUND: Comparative costing studies using real-world data stratified by patient case-mix, are valuable to decision makers for making reimbursement decisions of new interventions. This study evaluated real-world hospital admissions and short-term costs of transcatheter aortic valve implantation (TAVI) and isolated surgical aortic valve replacement (SAVR) for patients with aortic stenosis, stratified by the Society of Thoracic Surgeons (STS) risk scores. METHODS: Retrospective analysis of consecutive patients with a principal diagnosis of aortic stenosis who underwent isolated valve replacement at a single tertiary hospital, January 2012-December 2017. Patients were followed-up for 30 days post-procedure or until hospital discharge if index hospitalisation was greater than 30 days. Intensive care unit (ICU) and hospital length of stay (days), and costs in 2018 Australian dollars for the index procedure and 30-day follow-up were assessed. Multivariable generalised linear and two-part models with gamma distribution and log link function adjusting for Society of Thoracic Surgeons (STS) risk group and key sociodemographic characteristics were used. RESULTS: Of 488 patients, 61% males, median age 78 years (IQR 14 years), 221 (45%) received transcatheter aortic valve replacement (TAVI) and 267 (55%) received surgical aortic valve replacement (SAVR). STS risk scores were low (28%), intermediate (46%) and high (26%) for TAVI patients, and low (85%), intermediate (12%) and high (3%) for SAVR patients. When adjusted, TAVI length of stay was 57% shorter than SAVR (95% CI 31-83%, p<0.001) for intensive care unit (ICU) admission, and 64% shorter (95% CI 47-81%, p<0.001) for hospital admissions. TAVI costs were 13% lower than SAVR (95% CI 4-22%, p=0.005). CONCLUSION: This data suggests short-term health care costs are lower for patients with aortic stenosis undergoing TAVI than SAVR. A further roll-out of the TAVI program in hospitals across Australia may result in savings to the health system.

Contemporary outcomes of continuous-flow biventricular assist devices.

BACKGROUND: Significant right ventricular failure (RVF) complicating left ventricular assist device (LVAD) placement has been reported at 10-30%. Although primarily indicated for left ventricular failure, ventricular assist devices (VADs) have become utilized in a biventricular setup to combat right ventricular failure (RVF) following LVAD implantation. With the advent of continuous-flow LVADs (CF-LVADs) superseding their pulsatile predecessors, the shift towards CF-biventricular assist devices (CF-BiVADs) come with the prospect of improved outcomes over previous pulsatile BiVADs. We aim to review the literature and determine the outcomes of CF-BiVAD recipients. METHODS: A systematic review was performed to determine the outcomes of CF-BiVADs. Pre-operative demographics and device configuration data was collected. Primary outcomes evaluated were short-term survival, long-term survival, duration of support, and survival to transplant. Secondary outcomes evaluated included intensive care unit (ICU) and hospital length of stay (ICU-LOS and HLOS, respectively), pump thrombosis, pump exchange. Median and interquartile range was reported where appropriate. A major limitation was the likely overlap of cohorts across publications, which may have contributed to some selection bias. RESULTS: Of 1,282 screened, 12 publications were evaluated. Sample size ranged from 4 to 93 CF-BiVAD recipients, and follow-up ranged from 6 to 24 months. Mean age ranged from 34 to 52 years old. Forty-five percent of CF-BiVADs had right atrial (RA-) inflow cannulation, with the remaining being right ventricular (RV). Thirty-day survival was a median of 90% (IQR 82-97.8%) and 12-month survival was a median of 58.5% (IQR 47.5-62%). Where reported, rate of pump thrombosis (predominantly the right VAD) was a median of 31% (IQR 14-36%), although pump exchange was only 9% (IQR 1.5-12.5%). CONCLUSIONS: RVF post-LVAD implantation is a high morbidity and mortality complication. There is no on-label continuous-flow RVAD currently available. Thus, the modifications of LVADs for right ventricular support to combat pump thrombosis has resulted in various techniques. BiVAD recipients are predominantly transplant candidates, and complications of pump thrombosis and driveline infection whilst on wait-list are of great consequence. This study demonstrates the need for an on-label CF-BiVAD.

Minimally-invasive versus transcatheter aortic valve implantation: systematic review with meta-analysis of propensity-matched studies.

BACKGROUND: Minimally invasive aortic valve replacement (MiAVR) and transcatheter aortic valve implantation (TAVI) provide aortic valve replacement (AVR) by less invasive methods than conventional surgical AVR, by avoiding complete sternotomy. This study directly compares and analyses the available evidence for early outcomes between these two AVR methods. METHODS: Electronic databases were searched from inception until August 2019 for studies comparing MiAVR to TAVI, according to predefined search criteria. Propensity-matched studies with sufficient data were included in a meta-analysis. RESULTS: Eight studies with 9,744 patients were included in the quantitative analysis. Analysis of risk-matched patients showed no difference in early mortality (RR 0.76, 95% CI, 0.37-1.54, P=0.44). MiAVR had a signal towards lower rate of postoperative stroke, although this did not reach statistical significance (OR 0.42, 95% CI, 0.13-1.29, P=0.13). MiAVR had significantly lower rates of new pacemaker (PPM) requirement (OR 0.29, 95% CI, 0.16-0.52, P<0.0001) and postoperative aortic insufficiency (AI) or paravalvular leak (PVL) (OR 0.05, 95% CI, 0.01-0.20, P<0.0001) compared to TAVI, (OR 0.42, 95% CI, 0.13-1.29, P=0.13), while acute kidney injury (AKI) was higher in MiAVR compared to TAVI (11.1% vs. 5.2%, OR 2.28, 95% CI, 1.25-4.16, P=0.007). CONCLUSIONS: In patients of equivalent surgical risk scores, MiAVR may be performed with lower rates of postoperative PPM requirement and AI/PVL, higher rates of AKI and no statistical difference in postoperative stroke or short-term mortality, compared to TAVI. Further prospective trials are needed to validate these results.

Silent brain infarcts and early cognitive outcomes after transcatheter aortic valve implantation: a systematic review and meta-analysis.

BACKGROUND: Silent brain infarcts (SBIs) are frequently identified after transcatheter aortic valve implantation (TAVI), when patients are screened with diffusion-weighted magnetic resonance imaging (DW-MRI). Outside the cardiac literature, SBIs have been correlated with progressive cognitive dysfunction; however, their prognostic utility after TAVI remains uncertain. This study's main goals were to explore (i) the incidence of and potential risk factors for SBI after TAVI; and (ii) the effect of SBI on early post-procedural cognitive dysfunction (PCD). METHODS AND RESULTS: A systematic literature review was performed to identify all publications reporting SBI incidence, as detected by DW-MRI after TAVI. Silent brain infarct incidence, baseline characteristics, and the incidence of early PCD were evaluated via meta-analysis and meta-regression models. We identified 39 relevant studies encapsulating 2408 patients. Out of 2171 patients who underwent post-procedural DW-MRI, 1601 were found to have at least one new SBI (pooled effect size 0.76, 95% CI: 0.72-0.81). The incidence of reported stroke with focal neurological deficits was 3%. Meta-regression noted that diabetes, chronic renal disease, 3-Tesla MRI, and pre-dilation were associated with increased SBI risk. The prevalence of early PCD increased during follow-up, from 16% at 10.0 ± 6.3 days to 26% at 6.1 ± 1.7 months and meta-regression suggested an association between the mean number of new SBI and incidence of PCD. The use of cerebral embolic protection devices (CEPDs) appeared to decrease the volume of SBI, but not their overall incidence. CONCLUSIONS: Silent brain infarcts are common after TAVI; and diabetes, kidney disease, and pre-dilation increase overall SBI risk. While higher numbers of new SBIs appear to adversely affect early neurocognitive outcomes, long-term follow-up studies remain necessary as TAVI expands to low-risk patient populations. The use of CEPD did not result in a significant decrease in the occurrence of SBI.

Postoperative Atrial Fibrillation After Cardiac Surgery: A Meta-Analysis.

BACKGROUND: Postoperative atrial fibrillation (POAF) is common after cardiac surgery and linked to poorer short-term and long-term outcomes; however, conflicting evidence exists on stroke risk and how the index procedure affects outcomes. This study aims to provide a comprehensive review of the published outcomes of POAF after cardiac surgery, examined as a whole and by index procedure. METHODS: A systematic review of POAF after cardiac surgery was conducted. Outcomes related to POAF were analyzed in a meta-analysis, and aggregate survival data were derived to examine long-term survival. RESULTS: Sixty-one studies with 239,018 patients were identified, the majority (78.7%) undergoing coronary surgery. POAF occurred in 25.5% of patients and was associated with significantly higher rates of early mortality and stroke (odds ratio [OR], 1.74; P < .001; and OR, 2.21, P < .001, respectively) along with longer intensive care and overall hospital length of stay (mean difference 0.8 days, P = .008; and mean difference 2.8 days, P < .001, respectively). After a median of 6.6 years (range, 0.5-20 years), mortality and stroke remained significantly higher for those with POAF (OR, 1.57, P < .001; and OR, 1.81, P = .001). Pooled hazard ratio for long-term mortality was significantly higher for patients who underwent coronary surgery compared with isolated valve surgery. CONCLUSIONS: POAF is common after cardiac surgery and is associated with significantly higher rates of both short-term and long-term stroke and mortality as well as increased hospital stay. Differences in hazard for long-term survival may be due to the underlying pathophysiological risk factors for POAF, which differ by surgical procedure.

Subclinical valve thrombosis in transcatheter aortic valve implantation: A systematic review and meta-analysis.

BACKGROUND: Recent high-resolution computed tomography studies after transcatheter aortic valve insertion (TAVI) have reported a high prevalence of subclinical valve thrombosis (SCVT), potentially contributing to increased risk of late stroke. We aimed to investigate SCVT in patients after TAVI, with a focus on prevalence, predisposing factors, management, and potential sequelae. METHODS: A comprehensive literature review of patients with SCVT after TAVI was carried out on all published studies in 3 major electronic databases from their inception until October 2019. Studies with sufficient data were included in a meta-analysis comparing the risk of stroke between patients with SCVT and those with normal valve function, as well as the protective effects of antiplatelet and anticoagulation on preventing SCVT. RESULTS: From 3456 patients examined in a comprehensive review, 398 patients (11.5%) demonstrated evidence of SCVT during follow-up. Dual antiplatelet therapy was given in 45.5% of cases, single antiplatelet therapy in 19.8%, and oral anticoagulation in 28.5%. A meta-analysis demonstrated that rates of stroke were more than 3 times greater in patients with SCVT compared with those without (logistic odds, 1.10; 95% confidence interval, 0.63-1.57, P < .0001). Oral anticoagulation was superior to dual antiplatelet therapy or single antiplatelet therapy, preventing the formation of SCVT (logistic odds, -1.05, 95% confidence interval, -1.71 to -0.39, P < .0001). CONCLUSIONS: Subclinical valve thrombosis is seen in 11.5% of patients after TAVI and is associated with increased risk of stroke. When oral anticoagulation is used postprocedurally, it is more effective than either dual or single-antiplatelet therapy in preventing subclinical valve thrombosis. These findings suggest that further studies are needed to define the optimal antithrombotic regimen to mitigate thrombotic and embolic sequelae after TAVI.

Aortic valve replacement using stented or sutureless/rapid deployment prosthesis via either full-sternotomy or a minimally invasive approach: a network meta-analysis.

BACKGROUND: New technologies such as sutureless or rapid deployment prosthetic valves and access via minimally invasive incisions offer alternatives to traditional full-sternotomy aortic valve replacement (SAVR). However, a comprehensive comparison of these surgical techniques along with alternative valve prosthesis has not been completed. METHODS: Electronic databases were searched for studies comparing outcomes for SAVR, minimally invasive AVR (MiAVR), sutureless/rapid-deployment AVR (SuAVR) via full-sternotomy, or minimally invasive SuAVR (MiSuAVR) from their inception until September 2018. Early postoperative outcomes and follow-up data were included in a Bayesian network meta-analysis. RESULTS: Twenty-three studies with 8,718 patients were identified. Compared with standard SAVR, SuAVR had significantly lower incidence of postoperative AF [odds ratio (OR) 0.33, 95% confidence interval (CI): 0.14-0.79, P=0.013] and MiSuAVR greater requirement for postoperative permanent pacemaker (OR 2.27, 95% CI: 1.25-4.14, P=0.008). All sutureless/rapid-deployment procedures had reduced cardiopulmonary bypass and cross-clamp times, by a mean of 25.9 and 25.0 min, respectively. Hospital length of stay (LOS), but not intensive care LOS, was reduced for all groups (MiAVR -1.53 days, MiSuAVR -2.79 days, and SuAVR 3.37 days). A signal towards reduced early mortality, wound infections, and acute kidney injury was noted in both sutureless/rapid-deployment and minimally invasive techniques but did not achieve significance. Sutureless/rapid-deployment procedures had favourable survival and freedom from valve related reoperation, however follow-up times were short and demonstrated significant heterogeneity between intervention groups. CONCLUSIONS: Minimally invasive and sutureless techniques demonstrate equivalent early postoperative outcomes to SAVR and may reduce ventilation time, hospital LOS and postoperative atrial fibrillation (POAF) burden.

Novel Oral Anticoagulants Compared to Warfarin for Postoperative Atrial Fibrillation After Isolated Coronary Artery Bypass Grafting.

BACKGROUND: Postoperative atrial fibrillation (POAF) is common after cardiac surgery and contributes to short- and long-term morbidity, particularly thromboembolism. Anticoagulation for sustained or recurrent POAF is suggested to reduce thromboembolism. Novel oral anticoagulants may present a safe alternative to warfarin with further benefits including shorter hospital length of stay and better patient convenience. METHODS: A retrospective analysis was performed on all isolated cases of coronary artery surgery (CABG) at our institution between January 2015 and December 2018, totalling 960 patients. Rates of POAF were examined with particular focus on preoperative factors, postoperative outcomes, and anticoagulation practices. RESULTS: The incidence of POAF was 31.8% (305 patients) and was higher in older patients (67.6±9.4 yrs vs 63.0±10.7 yrs, p<0.001), those with a history of cerebrovascular disease (14.6% vs 8.7%, p=0.02), those with higher CHADS-VASc scores (2.5±1.3 vs 2.8±1.3, p<0.001) those who had a postoperative return to theatre (2.6% vs 0.8%, p=0.002), and those with new renal failure (4.9% vs 1.8%, p=0.02). Off-pump surgery was associated with lower incidence of POAF (29.8% vs 37.1%, p=0.03). Patients who developed POAF had significantly longer admissions than those without (12.6±10.6 days vs 9.3±16.3 days, p<0.001). In total, 106 patients (11.0%) went home anticoagulated; 77 (72.6%) on warfarin and 29 (27.4% on a NOAC). Readmission for bleeding was higher in patients on anticoagulation (1.0% vs 0.0%, p=0.02), but did not drive readmission for pericardial effusion (0.3% vs 0.6%, p=0.55). No bleeding complications occurred in patients who were discharged on a NOAC. Overall mortality at median of 2 years was 1.8% (17 patients) and no mortality occurred in any patient discharged on anticoagulation. CONCLUSION: Postoperative atrial fibrillation is a common adverse event and is linked to higher preoperative and postoperative morbidity. Anticoagulation may be safely started in these patients and use of novel anticoagulation does not appear to increase postoperative complications, although overall numbers are low.

Evaluation of aortic stenosis using cardiovascular magnetic resonance: a systematic review & meta-analysis.

BACKGROUND: As the average age of patients with severe aortic stenosis (AS) who receive procedural intervention continue to age, the need for non-invasive modalities that provide accurate diagnosis and operative planning is increasingly important. Advances in cardiovascular magnetic resonance (CMR) over the past two decades mean it is able to provide haemodynamic data at the aortic valve, along with high fidelity anatomical imaging. METHODS: Electronic databases were searched for studies comparing CMR to transthoracic echocardiography (TTE) and transoesophageal echocardiography (TEE) in the diagnosis of AS. Studies were included only if direct comparison was made on matched patients, and if diagnosis was primarily through measurement of aortic valve area (AVA). RESULTS: Twenty-three relevant, prospective articles were included in the meta-analysis, totalling 1040 individual patients. There was no significant difference in AVA measured as by CMR compared to TEE. CMR measurements of AVA size were larger compared to TTE by an average of 10.7% (absolute difference: + 0.14cm2, 95% CI 0.07-0.21, p < 0.001). Reliability was high for both inter- and intra-observer measurements (0.03cm2 +/- 0.04 and 0.02cm2 +/- 0.01, respectively). CONCLUSIONS: Our analysis demonstrates the equivalence of AVA measurements using CMR compared to those obtained using TEE. CMR demonstrated a small but significantly larger AVA than TTE. However, this can be attributed to known errors in derivation of left ventricular outflow tract size as measured by TTE. By offering additional anatomical assessment, CMR is warranted as a primary tool in the assessment and workup of patients with severe AS who are candidates for surgical or transcatheter intervention.

New Onset Atrial Fibrillation Following Transcatheter and Surgical Aortic Valve Replacement: A Systematic Review and Meta-Analysis.

BACKGROUND: New-onset atrial fibrillation (NOAF) is a well-recognised, although variably reported complication following surgical aortic valve replacement (SAVR). Rates of NOAF following transcatheter aortic valve implantation (TAVI) seem to be notably less than SAVR, even though this population is typically older and of higher risk. The aim of this study was to determine the prevalence of NOAF in both these populations and associated postoperative outcomes. METHODS: We conducted a systematic review and meta-analysis of studies reporting rates of NOAF post SAVR or TAVI, along with early postoperative outcomes. Twenty-five (25) studies with a total of 13,010 patients were included in the final analysis. RESULTS: The prevalence of NOAF post SAVR was 0.4 (95% CI 0.36-0.44) and post TAVI 0.15 (95% CI 0.11-0.18). NOAF was associated with an increased risk of postoperative cerebrovascular accident (CVA) for SAVR and TAVI (RR 1.44 95% CI 1.01-2.06 and RR 2.24 95% CI 1.46-3.45 respectively). NOAF was associated with increased mortality in the TAVI group (RR 3.02 95% CI 1.55-5.9) but not the SAVR group (RR 1.00, 95% CI 0.54-1.84). Hospital length of stay was increased for both TAVI and SAVR patients with NOAF (MD 2.54 days, 95% CI 2.0-3.00) and (MD 1.64 days, 95% CI 0.04-3.24 respectively). CONCLUSIONS: The prevalence of NOAF is significantly less following TAVI, as compared to SAVR. While NOAF is associated with increased risk of postoperative stroke for both groups, for TAVI alone NOAF confers increased risk of early mortality.

Minimally invasive surgical approaches to left main and left anterior descending coronary artery revascularization are superior compared to first- and second-generation drug-eluting stents: a network meta-analysis.

OBJECTIVES: There are a number of minimally invasive approaches to revascularization of coronary artery disease that involve the left main or proximal left anterior descending artery; however, studies to date provide mixed results. METHODS: A Bayesian network meta-analysis was performed to compare early and late postoperative outcomes between percutaneous coronary intervention with first- and second-generation drug-eluting stents (DESs), off-pump coronary artery bypass and minimally invasive direct coronary artery bypass (MIDCAB) in patients with involvement of left main or left anterior descending disease. RESULTS: A total of 37 studies with 31 728 patients were included in the analysis. There were no significant differences in early mortality rates, strokes or myocardial infarctions (MIs). The long-term all-cause mortality rate was equivalent between the groups. Patients who had off-pump coronary artery bypass had fewer late MI compared with those who had first-generation DES (DES1) [odds ratio (OR) 0.38, 95% confidence interval (CI) 0.20-0.72] and MIDCAB (OR 0.41, 95% CI 0.17-0.97) and reduced late target vessel revascularization compared with DES1 (OR 0.17, 95% CI 0.09-0.32) and second-generation DES (DES2) (OR 0.32, 95% CI 0.14-0.72). The rate of late major adverse cardiac events was lower with off-pump coronary artery bypass compared with that with DES1 (OR 0.33, 95% CI 0.26-0.43) and DES2 (OR 0.62, 95% CI 0.45-0.90). The rate of late major adverse cardiac events with MIDCAB was lower than that with DES1 (OR 0.43, 95% CI 0.31-0.62) as was that with DES2 compared with DES1 (OR 0.53, 95% CI 0.39-0.70). CONCLUSIONS: Surgical approaches to left main or proximal left anterior descending disease remain superior to first- or second-generation DES in terms of long-term freedom from MI and target vessel revascularization as well as improved overall long-term survival. Conflicting rates of late MI and target vessel revascularization in patients who underwent MIDCAB suggest disease in alternate vessels that may best be approached via hybrid techniques.

Silent Brain Infarcts Following Cardiac Procedures: A Systematic Review and Meta-Analysis.

Background Silent brain infarcts ( SBI ) are increasingly being recognized as an important complication of cardiac procedures as well as a potential surrogate marker for studies on brain injury. The extent of subclinical brain injury is poorly defined. Methods and Results We conducted a systematic review and meta-analysis utilizing studies of SBI s and focal neurologic deficits following cardiac procedures. Our final analysis included 42 studies with 49 separate intervention groups for a total of 2632 patients. The prevalence of SBI s following transcatheter aortic valve implantation was 0.71 (95% CI 0.64-0.77); following aortic valve replacement 0.44 (95% CI 0.31-0.57); in a mixed cardiothoracic surgery group 0.39 (95% CI 0.28-0.49); coronary artery bypass graft 0.25 (95% CI 0.15-0.35); percutaneous coronary intervention 0.14 (95% CI 0.10-0.19); and off-pump coronary artery bypass 0.14 (0.00-0.58). The risk ratio of focal neurologic deficits to SBI in aortic valve replacement was 0.22 (95% CI 0.15-0.32); in off-pump coronary artery bypass 0.21 (95% CI 0.02-2.04); with mixed cardiothoracic surgery 0.15 (95% CI 0.07-0.33); coronary artery bypass graft 0.10 (95% CI 0.05-0.18); transcatheter aortic valve implantation 0.10 (95% CI 0.07-0.14); and percutaneous coronary intervention 0.06 (95% CI 0.03-0.14). The mean number of SBI s per patient was significantly higher in the transcatheter aortic valve implantation group (4.58 ± 2.09) compared with both the aortic valve replacement group (2.16 ± 1.62, P=0.03) and the percutaneous coronary intervention group (1.88 ± 1.02, P=0.03). Conclusions SBI s are a very common complication following cardiac procedures, particularly those involving the aortic valve. The high frequency of SBI s compared with strokes highlights the importance of recording this surrogate measure in cardiac interventional studies. We suggest that further work is required to standardize reporting in order to facilitate the use of SBI s as a routine outcome measure.

Replacement of the aortic root with a composite valve-graft conduit: risk factor analysis in 246 consecutive patients.

BACKGROUND: Composite valve-graft (CVG) replacement of the aortic root is a well-studied and recognised treatment for various aortic root conditions, including valvular disease with associated aortopathy. There have been few previous studies of the procedure in large numbers in an Australian setting. METHOD: From January 2006 to June 2013, 246 successive patients underwent CVG root replacements at our institution. Mean age was 56.8 years, 85.4% were male, and 87 had evidence of bicuspid aortic valve. Indications for operation included ascending aortic aneurysm in 222 patients, annuloaortic ectasia in 67 patients, and aortic dissection in 38 patients. RESULTS: The overall unit 30-day mortality was 5.7%, including: elective 30-day mortality of 2.2%, and emergent 30-day mortality of 17.2%. Statistically significant multivariate predictors of 30-day mortality were: acute aortic dissection (OR=20.07), peripheral vascular disease (OR=11.17), new ventricular tachycardia (OR=30.17), re-operation for bleeding (OR=14.42), concomitant mitral stenosis (OR=68.30), and cerebrovascular accident (OR=144.85). CONCLUSIONS: Low postoperative mortality in our series matches closely with results from similar sized international studies, demonstrating that this procedure can be performed with low risk in centres with sufficient experience in the operative procedure.

Normalisation of haemodynamics in patients with end-stage heart failure with continuous-flow left ventricular assist device therapy.

BACKGROUND: New generation continuous-flow left ventricular assist devices (LVADs) utilise centrifugal pumps. Data concerning their effect on patient haemodynamics, ventricular function and tissue perfusion is limited. We aimed to document these parameters following HeartWare centrifugal continuous-flow LVAD (HVAD) implantation and to assess the impact of post-operative right heart failure (RHF). METHODS: We reviewed 53 consecutive patients (mean age 49.5 ± 14.1 yrs) with HVAD implanted in the left ventricle, at St. Vincent's Hospital, Sydney, between January 2007 and August 2012. Available paired right heart catheterisation (n=35) and echocardiography (n=39) data was reviewed to assess response of invasive haemodynamics and ventricular function to LVAD support. RESULTS: A total of 28 patients (53%) were implanted from interim mechanical circulatory support. Seventeen patients (32%) required short-term post-implant veno-pulmonary artery extracorporeal membrane oxygenation. At 100 ± 61 days post-implant, mean pulmonary artery pressure and mean pulmonary capillary wedge pressure decreased from 38.8 ± 7.7 to 22.9 ± 7.7 mmHg and 28.3 ± 6.4 to 13.4 ± 5.4 mmHg respectively (p<0.001). LV end diastolic diameter decreased from 71.3 ± 12.7 to 61.1 ± 13.7 mm and LV end-systolic diameter from 62.7 ± 12.3 to 53.9 ± 14.4mm (p<0.001). Aortic regurgitation remained trivial. Serum sodium increased from 133.3 ± 5.7 to 139.3 ± 2.8 mmol/L and creatinine decreased from 109.1 ± 42.5 to 74.3 ± 26.2 µmol/L (p<0.001). Across the entire cohort, the six-month survival/transplant rate was significantly lower for RHF patients (72.2%, n=18) compared to those without (96.9%, n=35, p=0.01). CONCLUSIONS: HVAD support improves haemodynamics, LV dimensions and renal function. Following implantation with a centrifugal continuous-flow LVAD, RHF remains a significant risk with a tendency to worse outcomes in the short to medium term.

Derivation of indices of left ventricular contractility in the setting of continuous-flow left ventricular assist device support.

It is important to accurately monitor residual cardiac function in patients under long-term continuous-flow left ventricular assist device (cfLVAD) support. Two new measures of left ventricular (LV) chamber contractility in the cfLVAD-unloaded ventricle include IQ, a regression coefficient between maximum flow acceleration and flow pulsatility at different pump speeds; and K, a logarithmic relationship between volumes moved in systole and diastole. We sought to optimize these indices. We also propose RIQ, a ratio between maximum flow acceleration and flow pulsatility at baseline pump speed, as an alternative to IQ. Eleven patients (mean age 49 ± 11 years) were studied. The K index was derived at baseline pump speed by defining systolic and diastolic onset as time points at which maximum and minimum volumes move through the pump. IQ across the full range of pump speeds was markedly different between patients. It was unreliable in three patients with underlying atrial fibrillation (coefficient of determination R(2) range: 0.38-0.74) and also when calculated without pump speed manipulation (R(2) range: 0.01-0.74). The K index was within physiological ranges, but poorly correlated to both IQ (P = 0.42) and RIQ (P = 0.92). In four patients there was excellent correspondence between RIQ and IQ, while four other patients showed a poor relationship between these indices. As RIQ does not require pump speed changes, it may be a more clinically appropriate measure. Further studies are required to determine the validity of these indices.