Multicentre analysis of current strategies and outcomes in open aortic arch surgery: heterogeneity is still an issue.

OBJECTIVES: The study was conducted to evaluate, on the basis of a multicentre analysis, current results of elective open aortic arch surgery performed during the last decade. METHODS: Data of 1232 consecutive patients who underwent aortic arch repair with reimplantation of at least one supra-aortic artery between 2004 and 2013 were collected from 11 European cardiovascular centres, and retrospective statistical examination was performed using uni- and multi-variable analyses to identify predictors for 30-day mortality. Acute aortic dissections and arch surgeries not involving the supra-aortic arteries were not included. RESULTS: Arch repair involving all 3 arch arteries (total), 2 arch arteries (subtotal) or 1 arch artery (partial) was performed in 956 (77.6%), 155 (12.6%) and 121 (9.8%) patients, respectively. The patients' characteristics as well as the surgical techniques, including the method of cannulation, perfusion and protection, varied considerably between the clinics participating in the study. The in-hospital and 30-day mortality rates were 11.4 and 8.8% for the entire cohort, respectively, ranging between 1.7 and 19.0% in the surgical centres. Multivariable logistic regression analysis identified surgical centre, patient's age, number of previous surgeries with sternotomy and concomitant surgeries as independent risk factors of 30-day mortality. The follow-up of the study group was 96.5% complete with an overall follow-up duration of 3.3 ± 2.9 years, resulting in 4020 patient-years. After hospital discharge, 176 (14.3%) patients died, yielding an overall mortality rate of 25.6%. The actuarial survival after 5 and 8 years was 72.0 ± 1.5% and 64.0 ± 2.0, respectively. CONCLUSIONS: The surgical risk in elective aortic arch surgery has remained high during the last decade despite the advance in surgical techniques. However, the patients' characteristics, numbers of surgeries, the techniques and the results varied considerably among the centres. The incompleteness of data gathered retrospectively was not effective enough to determine advantages of particular cannulation, perfusion, protection or surgical techniques; and therefore, we strongly recommend further prospective multicentre studies, preferably registries, in which all relevant data have to be clearly defined and collected.

Short-term intravenous sodium nitrite infusion improves cardiac and pulmonary hemodynamics in heart failure patients.

BACKGROUND: Nitrite exhibits hypoxia-dependent vasodilator properties, selectively dilating capacitance vessels in healthy subjects. Unlike organic nitrates, it seems not to be subject to the development of tolerance. Currently, therapeutic options for decompensated heart failure (HF) are limited. We hypothesized that by preferentially dilating systemic capacitance and pulmonary resistance vessels although only marginally dilating resistance vessels, sodium nitrite (NaNO2) infusion would increase cardiac output but reduce systemic arterial blood pressure only modestly. We therefore undertook a first-in-human HF proof of concept/safety study, evaluating the hemodynamic effects of short-term NaNO2 infusion. METHODS AND RESULTS: Twenty-five patients with severe chronic HF were recruited. Eight received short-term (5 minutes) intravenous NaNO2 at 10 µg/kg/min and 17 received 50 µg/kg/min with measurement of cardiac hemodynamics. During infusion of 50 µg/kg/min, left ventricular stroke volume increased (from 43.22±21.5 to 51.84±23.6 mL; P=0.003), with marked falls in pulmonary vascular resistance (by 29%; P=0.03) and right atrial pressure (by 40%; P=0.007), but with only modest falls in mean arterial blood pressure (by 4 mm Hg; P=0.004). The increase in stroke volume correlated with the increase in estimated trans-septal gradient (=pulmonary capillary wedge pressure-right atrial pressure; r=0.67; P=0.003), suggesting relief of diastolic ventricular interaction as a contributory mechanism. Directionally similar effects were observed for the above hemodynamic parameters with 10 µg/kg/min; this was significant only for stroke volume, not for other parameters. CONCLUSIONS: This first-in-human HF efficacy/safety study demonstrates an attractive profile during short-term systemic NaNO2 infusion that may be beneficial in decompensated HF and warrants further evaluation with longer infusion regimens.

Role of aldehyde dehydrogenase in hypoxic vasodilator effects of nitrite in rats and humans.

BACKGROUND AND PURPOSE: Hypoxic conditions favour the reduction of nitrite to nitric oxide (NO) to elicit vasodilatation, but the mechanism(s) responsible for bioconversion remains ill defined. In the present study, we assess the role of aldehyde dehydrogenase 2 (ALDH2) in nitrite bioactivation under normoxia and hypoxia in the rat and human vasculature. EXPERIMENTAL APPROACH: The role of ALDH2 in vascular responses to nitrite was studied using rat thoracic aorta and gluteal subcutaneous fat resistance vessels from patients with heart failure (HF; 16 patients) in vitro and by measurement of changes in forearm blood flow (FBF) during intra-arterial nitrite infusion (21 patients) in vivo. Specifically, we investigated the effects of (i) ALDH2 inhibition by cyanamide or propionaldehyde and the (ii) tolerance-independent inactivation of ALDH2 by glyceryl trinitrate (GTN) on the vasodilator activity of nitrite. In each setting, nitrite effects were measured via evaluation of the concentration-response relationship under normoxic and hypoxic conditions in the absence or presence of ALDH2 inhibitors. KEY RESULTS: Both in rat aorta and human resistance vessels, dilatation to nitrite was diminished following ALDH2 inhibition, in particular under hypoxia. In humans there was a non-significant trend towards attenuation of nitrite-mediated increases in FBF. CONCLUSIONS AND IMPLICATIONS: In human and rat vascular tissue in vitro, hypoxic nitrite-mediated vasodilatation involves ALDH2. In patients with HF in vivo, the role of this enzyme in nitrite bioactivation is at the most, modest, suggesting the involvement of other more important mechanisms.

One-stage repair in complex multisegmental thoracic aneurysmal disease: results of a multicentre study.

OBJECTIVES: Patients with thoracic aneurysmal disease involving the arch and the descending or thoracoabdominal aorta may require more than one surgical intervention. The results of one-stage repair using a hybrid stent-graft in the frozen elephant trunk manner are presented. METHODS: Between January 2005 and March 2012, 113 (age 67 ± 10 years) of 358 registered patients in the International E-Vita Open Registry were operated on for combined arch and descending and thoracoabdominal aortic aneurysm. Thirty-one (27%) patients had a previous cardiothoracic, abdominal aortic surgery or endovascular repair. The E-Vita Open hybrid stent-graft was used in all cases. Postoperatively and during the follow-up (100%), aortic image examinations were performed. RESULTS: Combined arch replacement and antegrade stent-grafting distally (graft diameter 34 ± 4 mm) were performed under selective cerebral perfusion (72 ± 27 min) and hypothermic visceral ischaemia (65 ± 27 min). Postoperatively, aneurysm exclusion was completely and partially achieved in 80% and 20%, respectively. In-hospital mortality and survival rate after 5 years were 12% (13 of 113) and 78%, respectively. Latest aortic imaging demonstrated 93% complete aneurysm exclusion. Freedom from secondary endovascular intervention and open surgery were 88 and 90%, respectively. CONCLUSIONS: In multisegmental thoracic aneurysmal disease, combined arch replacement with distal repair by a hybrid stent-graft enables one-stage treatment with acceptable mortality. Aneurysm exclusion by the stent-graft seems to be primarily curative and allows easier access for distal open or endovascular reintervention.

Measurement of extravascular lung water following human brain death: implications for lung donor assessment and transplantation.

OBJECTIVES: The measurement of extravascular lung water could aid the assessment and guide the management of potential lung donors following brain death. We therefore sought to validate a single indicator thermodilution extravascular lung water index (EVLWI-T) measurement using gravimetry and to assess the impact and clinical correlates of elevated EVLWI-T in potential lung donors and transplant recipients. METHODS: In a prospective study, we measured serial EVLWI-T and haemodynamic and oxygenation data in 60 potential lung donors. To validate the EVLWI-T measurement, we measured in vivo thermodilution EVLWI (EVLWI-T) and gravimetric ex vivo EVLWI (EVLWI-G) in donor lungs rejected for transplant using the Holcroft and Trunkey modification of Pearce's method. We assessed the clinical correlates of elevated lung water and measured interleukin-8 and hepatocyte growth factor in bronchoalveolar lavage (BAL) fluid. RESULTS: The mean EVLWI-T (n = 60) was 9.7 (4.5) ml kg(-1), being >7-10 ml kg(-1) in 23/60 and >10 ml kg(-1) in 16/60 potential donors. Donor lungs with EVLWI >10 ml kg(-1) were more likely to be receiving norepinephrine (P = 0.04), have higher pulmonary capillary wedge pressures (P = 0.008), be unsuitable for transplantation (P = 0.007) and, if transplanted, have worse survival (P = 0.04). Lungs submitted to gravimetric analysis [n = 20 in 11 donors (9 double and 2 single)] had EVWLI-T of 10.8 (2.7) and EVLWI-G was 10.1 (2.5). There was a strong correlation between EVLW-T and EVLW-G (r = 0.7; P = 0.014), but EVLWI-T over-predicted the EVLWI-G by ≈ 1 ml kg(-1) (EVLW-T = 1.05 × EVLW-G). Cytokine levels in BAL fluid were elevated. CONCLUSIONS: Elevated lung water is found in >50% of potential lung donors, predicts lung suitability for transplant and may adversely affect recipient outcome. Although EVLWI-T intrinsically overestimates gravimetric lung water, its measurement may aid the assessment of organ suitability. Lung water accumulation and the proinflammatory response may both be targets for modifying therapy.

The future of aortic surgery in Europe.

At least every ten years, each specialty should reflect upon its past, its present and its future, in order to be able to reconfirm the direction in which it is headed, to adopt suggestions from inside and outside and, consequently, to improve. As such, the aim of this manuscript is to provide the interested reader with an overview of how aortic surgery and (perhaps more accurately) aortic medicine has evolved in Europe, and its present standing; also to provide a glimpse into the future, trying to disseminate the thoughts of a group of people actively involved in the development of aortic medicine in Europe, namely the Vascular Domain of the European Association of Cardio-Thoracic Surgery (EACTS).

Spontaneous aortic rupture early postpartum without trauma or connective tissue disorder.

Rupture of the thoracic aorta is a rare but recognized complication following pregnancy. The common causes of thoracic aortic rupture in the peripartum period are trauma, dissecting aneurysms and saccular aneurysms secondary to systemic connective tissue disease. We report a case of non-traumatic spontaneous aortic rupture in a patient without trauma or systemic connective tissue disease 1 day postpartum, which was successfully managed by surgical repair of the thoracic aorta.

A systematic review and meta-analysis of the cardioprotective effects of remote ischaemic preconditioning in open cardiac surgery.

OBJECTIVE: To investigate the cardioprotective efficacy of remote ischaemic preconditioning (RIPC) in cardiac surgery. DESIGN: We have performed a systematic search of MEDLINE, EMBASE and Cochrane Central Register of Controlled Trials to identify randomized controlled trials involving RIPC. SETTING: Randomized controlled trials of RIPC in open cardiac surgery patients. MAIN OUTCOME MEASURES: Meta-analysis was performed with the primary outcome the standardized mean difference between intervention and control groups in 12 hour postoperative troponin concentration. Heterogeneity was examined by fixed effects meta-regression. RESULTS: Ten studies with a total of 693 participants were included in the meta-analysis. RIPC reduced troponin levels 12 hours after surgery compared with control. The fixed and random effects differences were 0.35 (95% CI 0.19 to 0.51) and 0.53 (95% CI 0.18-0.88) respectively. However, important heterogeneity was present. Fixed effects meta-regression partially accounted for heterogeneity based on whether studies had full blinding, comprising blinding of patients, surgeons, anaesthetists and investigators. Studies with incomplete or no blinding demonstrated a larger estimate of effect, 0.74 (95% CI 0.47 to 1.00) compared to those with full blinding, 0.13 (95% CI - 0.07 to 0.33). CONCLUSIONS: Although our analysis suggests RIPC may result in cardiac protection during cardiac surgery, the effect was most marked in studies without full blinding, with a smaller and statistically non-significant effect in fully blinded studies. We propose that further double blind randomized controlled trials investigating the cardioprotective effects of RIPC in cardiac surgery are required to resolve the current clinical uncertainty.

Remote ischaemic preconditioning in coronary artery bypass surgery: a meta-analysis.

AIM: Randomised trials exploring remote ischaemic preconditioning (RIPC) in patients undergoing coronary artery bypass graft (CABG) surgery have yielded conflicting data regarding potential cardiovascular and renal protection, and are individually flawed by small sample size. METHODS: Three investigators independently searched the MEDLINE, EMBASE and Cochrane databases to identify randomised trials testing RIPC in patients undergoing CABG. RESULTS: Nine studies with 704 patients were included. Standardised mean difference of troponin I and T release showed a significant decrease (-0.36 (95% CI -0.62 to -0.09)). This difference held true after excluding the trials with cross-clamp fibrillation, the study with off-pump CABG and studies using a flurane as anaesthetic agent (-0.41 (95% CI -0.69 to -0.12), -0.38 (95% CI -0.70 to -0.07) and -0.37 (95% CI -0.63 to -0.12), respectively). A similar trend was also obtained for patients with multivessel disease (-0.41 (95% CI -0.73 to -0.08)). The trials evaluating postoperative creatinine reported a non-significant reduction (0.02 (95% CI -0.09 to 0.13)). Moreover, the length of in-hospital stay was not influenced by the kind of treatment (weighted mean difference 0.27 (95% CI -0.24 to 0.79)). CONCLUSION: RIPC reduced the release of troponin in patients undergoing CABG. Larger randomised trials are needed to clarify the presence of a causal relationship between RIPC-induced troponin release and clinical adverse events.

Effect of donor smoking on survival after lung transplantation: a cohort study of a prospective registry.

BACKGROUND: The risk that a positive smoking history in lung donors could adversely affect survival of transplant recipients causes concern. Conversely, reduction of the donor pool by exclusion of donors with positive smoking histories could compromise survival of patients waiting to receive a transplant. We examined the consequences of donor smoking on post-transplantation survival, and the potential effect of not transplanting lungs from such donors. METHODS: We analysed the effect of donor smoking on 3 year survival after first adult lung transplantation from brain-dead donors done between July 1, 1999, and Dec 31, 2010, by Cox regression modelling of data from the UK Transplant Registry. We estimated the effect of acceptance of lungs from donors with positive smoking histories on survival and compared it with the effect of remaining on the waiting list for a potential transplant from a donor with a negative smoking history donor, by analysing all waiting-list registrations during the same period with a risk-adjusted sequentially stratified Cox regression model. FINDINGS: Of 1295 lung transplantations, 510 (39%) used lungs from donors with positive smoking histories. Recipients of such lungs had worse 3 year survival after transplantation than did those who received lungs from donors with negative smoking histories (unadjusted hazard ratio [HR] 1·46, 95% CI 1·20-1·78; adjusted HR 1·36, 1·11-1·67). Independent factors affecting survival were recipient's age, donor-recipient cytomegalovirus matching, donor-recipient height difference, donor's sex, and total ischaemic time. Of 2181 patients registered on the waiting list, 802 (37%) died or were removed from the list without receiving a transplant. Patients receiving lungs from donors with positive smoking histories had a lower unadjusted hazard of death after registration than did those who remained on the waiting list (0·79, 95% CI 0·70-0·91). Patients with septic or fibrotic lung disease registered in 1999-2003 had risk-adjusted hazards of 0·60 (95% CI 0·42-0·87) and 0·39 (0·28-0·55), respectively. INTERPRETATION: In the UK, an organ selection policy that uses lungs from donors with positive smoking histories improves overall survival of patients registered for lung transplantation, and should be continued. Although lungs from such donors are associated with worse outcomes, the individual probability of survival is greater if they are accepted than if they are declined and the patient chooses to wait for a potential transplant from a donor with a negative smoking history. This situation should be fully explained to and discussed with patients who are accepted for lung transplantation. FUNDING: National Health Service Blood and Transplant.

Subtle changes in renal function are associated with differences in late survival following adult cardiac surgery.

OBJECTIVES: To determine the predictors of post-operative renal function following adult cardiac surgery, and to assess the influence of this on late survival. METHODS: Prospectively collected data were analysed on 8032 patients who underwent coronary artery bypass grafting, valve surgery or combined procedures from 1 January 1998 until 31 December 2008, who did not require preoperative renal replacement therapy. The estimated glomerular filtration rate (eGFR) was calculated by the Modification of Diet in Renal Disease formula accounting for ethnicity pre-operatively, post-operatively on the fourth post-operative day, and the post-operative nadir based upon the peak post-operative creatinine within 30 days of surgery. Late survival data were obtained from the UK Central Cardiac Audit Database (CCAD). Appropriate frailty analyses were conducted in R and model fit was compared using Aikaike's Information Criterion. Initial analysis intended to determine predictors of post-operative renal function including pre-operative eGFR, EuroSCORE and surgical procedure including the operative procedure and bypass time. Further analysis examined its influence on late survival. RESULTS: Median follow-up was 72 months (IQR 48-105) during which there were 904 late deaths. The most powerful predictor of the day 4 eGFR was the pre-operative eGFR but other factors contributed including increasing EuroSCORE and bypass time. The pre-operative eGFR was shown to be a strong and independent predictor of late outcome (P = 0.0001, HR 0.497 95%CI 0.434-564); however, model fit was significantly improved using the day 4 eGFR (P = 0.0001, HR 0.43 95%CI 0.385-0.482). No specific change in individual renal function was identified as a predictor of adverse late survival, and neither the pre-operative nor day 4 eGFR was predictive of the nadir of renal function. CONCLUSIONS: Subtle early changes in renal function at the time of surgery are powerful predictors of adverse late outcome and can be predicted by pre-operative renal function.

Chronic kidney disease after nonrenal solid organ transplantation: a histological assessment and utility of chronic allograft damage index scoring.

BACKGROUND: It is proposed that chronic calcineurin inhibitor (CNI) nephrotoxicity has a central role in chronic kidney disease after nonrenal solid organ transplantation (NRSOT), although there are little data on renal histology in this setting. The aim of this study was to assess the histological features and renal outcomes of a cohort of patients with chronic kidney disease after NRSOT. METHODS: Renal biopsies of 62 NRSOT recipients were evaluated for histological diagnoses. Biopsies were graded for chronic allograft damage index parameters and for arteriolar hyalinosis. The sum of all chronic allograft damage index parameters and arteriolar hyalinosis scores was called chronic damage index. RESULTS: The biopsies were performed at a median of 4 (range: 0.3-15.9) years after NRSOT and at serum creatinine of 318±17.7 µmol/L (mean±standard deviation). Twenty-two (35.5%) biopsies showed predominant features of chronic CNI nephrotoxicity, 27 (43.5%) predominant features of hypertensive nephropathy, and 12 (19.3%) an alternative primary renal pathology. Twenty-four (38.7%) patients had progression to end-stage renal disease, at a median of 1.5 (0-10.1) years after biopsy and 6.9 (0.3-19.2) years after NRSOT. The risk of renal progression was associated with in situ damage measured by chronic damage index. CONCLUSIONS: Although CNI nephrotoxicity is an important cause of renal failure after NRSOT, many patients do not have overt histological evidence of CNI toxicity. Quantitative parameters of chronic damage can stratify renal prognosis.

Evidence, lack of evidence, controversy, and debate in the provision and performance of the surgery of acute type A aortic dissection.

Acute type A aortic dissection is a lethal condition requiring emergency surgery. It has diverse presentations, and the diagnosis can be missed or delayed. Once diagnosed, decisions with regard to initial management, transfer, appropriateness of surgery, timing of operation, and intervention for malperfusion complications are necessary. The goals of surgery are to save life by prevention of pericardial tamponade or intra-pericardial aortic rupture, to resect the primary entry tear, to correct or prevent any malperfusion and aortic valve regurgitation, and if possible to prevent late dissection-related complications in the proximal and downstream aorta. No randomized trials of treatment or techniques have ever been performed, and novel therapies-particularly with regard to extent of surgery-are being devised and implemented, but their role needs to be defined. Overall, except in highly specialized centers, surgical outcomes might be static, and there is abundant room for improvement. By highlighting difficulties and controversies in diagnosis, patient selection, and surgical therapy, our over-arching goal should be to enfranchise more patients for treatment and improve surgical outcomes.

Endocrine changes in brain death and transplantation.

Following brain death (BD) many hormonal changes occur. These include an increase and then a fall in the levels of circulating catecholamines, reduced levels of anti-diuretic hormone and cortisol as well as alterations in the hypothalamic-pituitary thyroid axis consistent with the non-thyroidal illness syndrome. In an era when the numbers of potential recipients listed for transplantation are greater than the number of donors, with an increasing donor age, a detailed knowledge of the endocrine changes and pathophysiological consequences of these is essential to optimise the management of the brain-stem dead organ donor. There still remains significant debate as to whether hormone replacement therapy to correct the observed changes is beneficial.

UK guidelines for referral and assessment of adults for heart transplantation.

Patients with advanced heart failure have a dismal prognosis and poor quality of life. Heart transplantation provides an effective treatment for a subset of these patients. This article provides cardiologists with up-to-date information about referral for transplantation, the role of left ventricular assist devices prior to transplant, patient selection, waiting-list management and donor heart availability. Timing is of central importance; patients should be referred before complications (eg, cardiorenal syndrome or secondary pulmonary hypertension) have developed that will increase the risk of, or potentially contraindicate, transplantation. Issues related to heart failure aetiology, comorbidity and adherence to medical treatment are reviewed. Finally, the positive role that cardiologists can play in promoting and facilitating organ donation is discussed.

Recommendations for haemodynamic and neurological monitoring in repair of acute type a aortic dissection.

During treatment of acute type A aortic dissection there is potential for both pre- and intra-operative malperfusion. There are a number of monitoring strategies that may allow for earlier detection of potentially catastrophic malperfusion (particularly cerebral malperfusion) phenomena available for the anaesthetist and surgeon. This review article sets out to discuss the benefits of the current standard monitoring techniques available as well as desirable/experimental techniques which may serve as adjuncts in the monitoring of these complex patients.

Which troponometric best predicts midterm outcome after coronary artery bypass graft surgery?

BACKGROUND: Various troponin I measurements (troponometrics) have been used as surrogate markers of patient outcome after coronary artery bypass grafting (CABG). Our aim was to define the postoperative troponometric best able to predict in-hospital and late mortality. METHODS: In 440 patients (seen from January 2000 to September 2004) undergoing isolated on-pump CABG with standardized anesthesia, perfusion, cardioplegia, and postoperative care, we followed all-cause mortality (census June 2009, 100% complete). Subjects underwent troponin I (cardiac troponin I [cTnI]) estimation at baseline and 6, 12, 24, 48, and 72 hours postoperatively, and individual time-point cTnI (T6, T12, T24, T48, T72), peak cTnI (Cmax), increase in cTnI between 6 and 12 hours (T↑6-12) and 6 and 24 hours (T↑6-24), cumulative area under the curve cTnI (CAUC24, CAUC48, and CAUC72), and cTnI≥13 ng·mL(-1) at any time point were each analyzed using univariate and multivariable Cox models to identify the probability of in-hospital and late death. Logistic EuroSCOREs and calculated creatinine clearance (CrCl) were also included. The Akaike information criterion (AIC) was used to determine goodness of fit. RESULTS: There were 62 of 440 deaths after a median (interquartile range) follow-up period of 7.0 (5.7 to 8.1) years. Univariate Cox analysis demonstrated T12, T24, T48, T72, T↑6-12, T↑6-24, standardized CAUC24, CAUC48, and CAUC72 each to be predictors of midterm mortality. On Cox multivariable analysis in models incorporating both logistic EuroSCOREs and CrCl, both T72 (hazard ratio [HR], 95% confidence interval [CI], 1.10 [1.06 to 1.14]; p<0.001) and CAUC72 (1.45 [1.26 to 1.62], p<0.001) were identified as independent predictors of mortality. Of these, CAUC72 was superior based on the lowest AIC. CONCLUSIONS: In myocardial protection studies, serial troponin I data should be collected until 72 hours postoperatively to calculate CAUC72, as this troponometric best predicts midterm mortality.