A Large-Diameter Vascular Graft Replacing Animal-Derived Sealants With an Elastomeric Polymer.

INTRODUCTION: To assess the safety and efficacy of an experimental large-diameter vascular graft externally sealed with an elastomeric polymer when used as an interposition graft in the descending aorta of sheep. METHODS: The experimental vascular grafts as well as control gelatin sealed interposition grafts were inserted into the descending aorta of juvenile sheep. The grafts were assessed by time to hemostasis and blood loss during surgery and hematology and biochemistry panels at distinct time points. Magnetic resonance imaging (MRI) was performed at 3 and at 6 mo after surgery, after which the animals were euthanized and necropsies were carried out including macroscopic and microscopic examination of the grafts, anastomoses, and distal organs. RESULTS: All animals survived the study period. There was no perceivable difference in the surgical handling of the grafts. The median intraoperative blood loss was 27.5 mL (range 10.0-125.0 mL) in the experimental group and 50.0 mL (range 10.0-75.0 mL) in the control group. The median time to hemostasis was 5.0 min (range 2.0-16.0 min) minutes in the experimental group versus 6.0 min (range 4.0-6.0 min) in the control group. MRI showed normal flow and graft patency in both groups. Healing and perianastomotic endothelialization was similar in both groups. CONCLUSIONS: The experimental graft has a similar safety and performance profile and largely comparable necropsy results, in comparison to a commonly used prosthetic vascular graft, with the experimental grafts eliciting a nonadherent external fibrous capsule as the major difference compared to the control grafts that were incorporated into the periadventitia. Survival, hemostatic sealing, and hematologic and radiologic results were comparable between the study groups.

Percutaneous coronary angioplasty versus coronary artery bypass grafting in the treatment of unprotected left main stenosis: updated 5-year outcomes from the randomised, non-inferiority NOBLE trial.

BACKGROUND: Percutaneous coronary intervention (PCI) is increasingly used in revascularisation of patients with left main coronary artery disease in place of the standard treatment, coronary artery bypass grafting (CABG). The NOBLE trial aimed to evaluate whether PCI was non-inferior to CABG in the treatment of left main coronary artery disease and reported outcomes after a median follow-up of 3·1 years. We now report updated 5-year outcomes of the trial. METHODS: The prospective, randomised, open-label, non-inferiority NOBLE trial was done at 36 hospitals in nine northern European countries. Patients with left main coronary artery disease requiring revascularisation were enrolled and randomly assigned (1:1) to receive PCI or CABG. The primary endpoint was major adverse cardiac or cerebrovascular events (MACCE), a composite of all-cause mortality, non-procedural myocardial infarction, repeat revascularisation, and stroke. Non-inferiority of PCI to CABG was defined as the upper limit of the 95% CI of the hazard ratio (HR) not exceeding 1·35 after 275 MACCE had occurred. Secondary endpoints included all-cause mortality, non-procedural myocardial infarction, and repeat revascularisation. Outcomes were analysed in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, NCT01496651. FINDINGS: Between Dec 9, 2008, and Jan 21, 2015, 1201 patients were enrolled and allocated to PCI (n=598) or CABG (n=603), with 17 subsequently lost to early follow-up. 592 patients in each group were included in this analysis. At a median of 4·9 years of follow-up, the predefined number of events was reached for adequate power to assess the primary endpoint. Kaplan-Meier 5-year estimates of MACCE were 28% (165 events) for PCI and 19% (110 events) for CABG (HR 1·58 [95% CI 1·24-2·01]); the HR exceeded the limit for non-inferiority of PCI compared to CABG. CABG was found to be superior to PCI for the primary composite endpoint (p=0·0002). All-cause mortality was estimated in 9% after PCI versus 9% after CABG (HR 1·08 [95% CI 0·74-1·59]; p=0·68); non-procedural myocardial infarction was estimated in 8% after PCI versus 3% after CABG (HR 2·99 [95% CI 1·66-5·39]; p=0·0002); and repeat revascularisation was estimated in 17% after PCI versus 10% after CABG (HR 1·73 [95% CI 1·25-2·40]; p=0·0009). INTERPRETATION: In revascularisation of left main coronary artery disease, PCI was associated with an inferior clinical outcome at 5 years compared with CABG. Mortality was similar after the two procedures but patients treated with PCI had higher rates of non-procedural myocardial infarction and repeat revascularisation. FUNDING: Biosensors.

Impaired renal function impacts negatively on vascular stiffness in patients with coronary artery disease.

BACKGROUND: Chronic kidney disease (CKD) and coronary artery disease (CAD) are independently associated with increased vascular stiffness. We examined whether renal function contributes to vascular stiffness independently of CAD status. METHODS: We studied 160 patients with CAD and 169 subjects without CAD. The 4-variable MDRD formula was used to estimate glomerular filtration rate (eGFR); impaired renal function was defined as eGFR <60 mL/min. Carotid-femoral pulse wave velocity (PWV) was measured with the SphygmoCor® device. Circulating biomarkers were assessed in plasma using xMAP® multiplexing technology. RESULTS: Patients with CAD and impaired renal function had greater PWV compared to those with CAD and normal renal function (10.2 [9.1;11.2] vs 7.3 [6.9;7.7] m/s; P < 0.001). In all patients, PWV was a function of eGFR (ß = -0.293; P < 0.001) even after adjustment for age, sex, systolic blood pressure, body mass index and presence or absence of CAD. Patients with CAD and impaired renal function had higher levels of adhesion and inflammatory molecules including E-selectin and osteopontin (all P < 0.05) compared to those with CAD alone, but had similar levels of markers of oxidative stress. CONCLUSIONS: Renal function is a determinant of vascular stiffness even in patients with severe atherosclerotic disease. This was paralleled by differences in markers of cell adhesion and inflammation. Increased vascular stiffness may therefore be linked to inflammatory remodeling of the vasculature in people with impaired renal function, irrespective of concomitant atherosclerotic disease.

Cardiac magnetic resonance findings predict increased resource utilization in elective coronary artery bypass grafting.

Morbidity following CABG (coronary artery bypass grafting) is difficult to predict and leads to increased healthcare costs. We hypothesized that pre-operative CMR (cardiac magnetic resonance) findings would predict resource utilization in elective CABG. Over a 12-month period, patients requiring elective CABG were invited to undergo CMR 1 day prior to CABG. Gadolinium-enhanced CMR was performed using a trueFISP inversion recovery sequence on a 1.5 tesla scanner (Sonata; Siemens). Clinical data were collected prospectively. Admission costs were quantified based on standardized actual cost/day. Admission cost greater than the median was defined as 'increased'. Of 458 elective CABG cases, 45 (10%) underwent pre-operative CMR. Pre-operative characteristics [mean (S.D.) age, 64 (9) years, mortality (1%) and median (interquartile range) admission duration, 7 (6-8) days] were similar in patients who did or did not undergo CMR. In the patients undergoing CMR, eight (18%) and 11 (24%) patients had reduced LV (left ventricular) systolic function by CMR [LVEF (LV ejection fraction) <55%] and echocardiography respectively. LE (late enhancement) with gadolinium was detected in 17 (38%) patients. The average cost/day was $2723. The median (interquartile range) admission cost was $19059 ($10891-157917). CMR LVEF {OR (odds ratio), 0.93 [95% CI (confidence interval), 0.87-0.99]; P=0.03} and SV (stroke volume) index [OR 1.07 (95% CI, 1.00-1.14); P=0.02] predicted increased admission cost. CMR LVEF (P=0.08) and EuroScore tended to predict actual admission cost (P=0.09), but SV by CMR (P=0.16) and LV function by echocardiography (P=0.95) did not. In conclusion, in this exploratory investigation, pre-operative CMR findings predicted admission duration and increased admission cost in elective CABG surgery. The cost-effectiveness of CMR in risk stratification in elective CABG surgery merits prospective assessment.

Low-density lipoprotein cholesterol determines oxidative stress and endothelial dysfunction in saphenous veins from patients with coronary artery disease.

OBJECTIVE: There is evidence for a relationship between endothelial dysfunction and cardiovascular disease, but a causative role for oxidative stress remains to be determined. METHODS AND RESULTS: We studied 188 patients with severe coronary artery disease (CAD), of whom 51 were age and sex matched with 51 healthy controls undergoing varicose vein surgery. Relaxation of saphenous vein to calcium ionophore, apocynin, and allopurinol was studied together with the markers of oxidative stress, total antioxidant capacity and reduced/oxidized glutathione ratio. Vascular superoxide levels were measured using lucigenin chemiluminescence and hydroethidine. Relaxation to calcium ionophore was decreased in CAD compared with control patients (maximum relaxation 26+/-2% versus 60+/-1%; P<0.001). Total superoxide production was increased (0.89+/-0.09 versus 0.56+/-0.06 nmol/mg per min; P=0.008), whereas superoxide inhibition with apocynin or allopurinol had a greater effect on vasorelaxation in CAD patients. Low-density lipoprotein (LDL) cholesterol predicted relaxation to calcium ionophore (P<0.001) and oxidative stress markers (P<0.001) in CAD patients. CONCLUSIONS: Endothelial dysfunction is associated with raised levels of superoxide and biomarkers of oxidative stress in saphenous veins from CAD patients. LDL cholesterol is a major determinant of endothelial dysfunction and oxidative stress in these patients. These results support intensive LDL cholesterol-lowering therapy as suggested by recent clinical trials.

Outcomes of off-pump coronary artery bypass surgery: current best available evidence.

In the last decade, there has been an upsurge of interest in less invasive alternatives to standard coronary artery bypass grafting performed with cardiopulmonary bypass. Off-pump coronary artery bypass grafting is one such less invasive alternative that has seen a resurgence in the last 10 years. The development and application of the technology required has largely been driven by the hope of decreasing the incidence and/or severity of the adverse outcomes associated with cardiopulmonary bypass, the idea being to perform coronary artery bypass grafting without cardiopulmonary bypass. A number of studies that have reported the safety and efficacy of off-pump coronary artery bypass surgery have provided the impetus for the development of this technology over the last decade. Despite tremendous enthusiasm on the part of cardiac surgeons, patients, industry and the media, skepticism still exists about the actual impact of off-pump coronary artery bypass grafting on the outcomes after coronary artery bypass grafting. The only means of countering this skepticism is to validate the safety and efficacy of off-pump coronary artery bypass surgery through the explicit and conscientious assessment of current best evidence. This review article attempts to evaluate the current best evidence available from randomized, controlled trials in order to compare the outcomes of off-pump coronary artery bypass surgery and conventional coronary artery bypass grafting.

Advanced mechanical circulatory support for post-cardiotomy cardiogenic shock: a 20-year outcome analysis in a non-transplant unit.

BACKGROUND: Post-cardiotomy cardiogenic shock (PCCS) has an incidence of 2-6 % after routine adult cardiac surgery. 0.5-1.5 % are refractory to inotropic and intra-aortic balloon pump (IABP) support. Advanced mechanical circulatory support (AMCS) can be used to salvage carefully selected number of such patients. High costs and major complication rates have lead to centralization and limited funding for such devices in the UK. We have looked the outcomes of such devices in a non-transplant, intermediate-size adult cardiothoracic surgery unit. METHODS: Inclusion criteria included any adult patient who had received salvage veno-arterial extra-corporeal membrane oxygenation (V-A ECMO) or a ventricular assist device (VAD) for PCCS refractory to IABP and inotropic support following cardiac surgery from April 1995-April 2015. RESULTS: Sixteen patients met the inclusion criteria. Age range was 34-83 years (median 71). There was a male predominance of 12 (75 %). Overall, 15 (94 %) had received ECMO of which, 10 (67 %) had received central ECMO and 5 (33 %) had received peripheral ECMO. One patient (6 %) had a VAD. The most common complication was haemorrhage. Stroke, femoral artery pseudo-aneurysm, sepsis and renal failure also occurred. Thirty-day survival was 37.5 %. Survival rate to hospital discharge was 31.2 %. All survivors had NYHA class I-II at 24 months follow-up. CONCLUSIONS: Our survival rate is similar to that reported in several previous studies. However, the use of AMCS for refractory PCCS is associated with serious complications. The survivors in our cohort appear to maintain an acceptable quality of life.

A 20-year multicentre outcome analysis of salvage mechanical circulatory support for refractory cardiogenic shock after cardiac surgery.

BACKGROUND: Refractory post-cardiotomy cardiogenic shock (PCCS) is a relatively rare phenomenon that can lead to rapid multi-organ dysfunction syndrome and is almost invariably fatal without advanced mechanical circulatory support (AMCS), namely extra-corporeal membrane oxygenation (ECMO) or ventricular assist devices (VAD). In this multicentre observational study we retrospectively analyzed the outcomes of salvage venoarterial ECMO (VA ECMO) and VAD for refractory PCCS in the 3 adult cardiothoracic surgery centres in Scotland over a 20-year period. METHODS: The data was obtained through the Edinburgh, Glasgow and Aberdeen cardiac surgery databases. Our inclusion criteria included any adult patient from April 1995 to April 2015 who had received salvage VA ECMO or VAD for PCCS refractory to intra-aortic balloon pump (IABP) and maximal inotropic support following adult cardiac surgery. RESULTS: A total of 27 patients met the inclusion criteria. Age range was 34-83 years (median 51 years). There was a large male predominance (n = 23, 85 %). Overall 23 patients (85 %) received VA ECMO of which 14 (61 %) had central ECMO and 9 (39 %) had peripheral ECMO. Four patients (15 %) were treated with short-term VAD (BiVAD = 1, RVAD = 1 and LVAD = 2). The most common procedure-related complication was major haemorrhage (n = 10). Renal failure requiring renal replacement therapy (n = 7), fatal stroke (n = 5), septic shock (n = 2), and a pseudo-aneurysm at the femoral artery cannulation site (n = 1) were also observed. Overall survival to hospital discharge was 40.7 %. All survivors were NYHA class I-II at 12 months' follow-up. CONCLUSION: AMCS for refractory PCCS carries a survival benefit and achieves acceptable functional recovery despite a significant complication rate.

How to make an aortic root replacement simulator at home.

There is a paucity of low-fidelity and cost-efficient simulators for training cardiac surgeons in the aspects of aortic root/valve replacement. In this study we addressed this training challenge by creating a low-fidelity, low-cost but, at the same time, anatomically realistic aortic root replacement simulator for training purposes. We used readily available, low cost materials such as lint roller tubes, foam sheet, press-and-seal bags, glue, plywood sheet, heat-shrink sleeving tubes and condoms as the basic material to create a low-fidelity, aortic root, training simulator. We constructed a multi-purpose, anatomically realistic aortic root simulator using the above materials, both time- and cost-efficiently, using the minimum of surgical equipment. This simulator is easy to construct and enables self-training in major techniques of aortic root replacement as well as in stentless valve implantation for trainees in cardiac surgery.

Duroflo II heparin bonding does not attenuate cytokine release or improve pulmonary function.

BACKGROUND: Comparison of the cytokine generation and leukocyte activation properties of Duroflo II heparin bonded bypass circuit (Baxter Healthcare Corp, Compton, UK) and the conventional cardiopulmonary bypass circuit. Attempt to correlate these to pulmonary dysfunction postoperatively. METHODS: Forty patients undergoing elective, isolated coronary artery bypass grafting were randomly allocated to have either plain extracorporeal circuits (group C) or heparin bonded extracorporeal circuits (group H). Full systemic heparinization was used in all patients. The inflammatory response was assessed by measuring plasma levels of interleukin-6, interleukin-8, interleukin-10, and polymorphonuclear elastase. Gas exchange was assessed by measuring the PaO2/FIO2 ratio. RESULTS: Significant impairment of oxygenation was seen in both groups with the lowest values at the end of the operation before a gradual return to normal during the next 6 hours. There were no differences between the groups in gas exchange or times to extubation. There were significant elevations in all the cytokines, with interleukin-6 levels peaking at 4 hours in group H and 24 hours in group C, before starting to return to normal at 48 hours. The patterns of interleukin-8 and interleukin-10 rise were identical in the two groups. Polymorphonuclear elastase reached a peak at the end of the operation in group H and remained elevated up to 24 hours, whereas levels continued to rise in group C up to 4 hours. There were no significant differences in levels between groups at any time. There were no differences between the groups in blood loss or blood product usage. CONCLUSIONS: Cardiopulmonary bypass induces a systemic inflammatory response with release of cytokines and activation of leukocytes. This correlates with the severe deterioration in pulmonary gas exchange from preoperative levels up to 6 hours postoperatively (p < 0.05). In the presence of systemic heparinization, Duroflo II heparin bondingtf the circuits has minor effects on the pattern of evolution of this inflammatory response.

Transcatheter aortic valve implantation: from fantasy to reality.

Increased life expectancy has led to the presentation of more complicated patients in old age for the replacement of the aortic valve. The emergence of Transcatheter Aortic Valve Implantation (TAVI) was considered as a significant breakthrough in the management of symptomatic, moribund patients suffering from aortic valve stenosis who had been rejected for surgical intervention. A novel technology often has a long journey from the point at which it is created to its every-day-use. It is now obvious that TAVI practice in multiple institutes around the world has gone beyond the evidence. Serious concerns have been raised questioning the current TAVI practice. Analysis of future TAVI use may assist clinicians and healthcare managers to understand and deploy this technology in accordance with the evidence.

Is it safe to divide and ligate the left innominate vein in complex cardiothoracic surgeries?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether it is safe to divide the left innominate vein (LIV) in aortic arch surgery to improve access. Altogether, 228 relevant papers were found using the reported search, of which nine represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Following LIV division, the venous drainage takes place via multiple collateral systems such as the azygous/hemiazygous, the internal mammary veins, the lateral thoracic and superficial thoracoabdominal veins, vertebral venous plexus as well as the transverse sinus. The possible complications are mainly left upper limb swelling and neurological symptoms. In one case series of 14 patients, the LIV was divided and ligated to facilitate the exposure for aortic arch surgery. More than 2-year follow-up did not reveal upper limb oedema or neurological symptoms. In two cohorts of 52 patients, the LIV was ligated prior to the superior vena cava (SVC) resection for malignancy. During the mid-term follow-up, no neurological or upper limb symptoms were reported. Although in two studies with 72 and 70 patients undergoing SVC resection it was not specified how many of them had LIV ligation, no relevant complications were reported. In a report, LIV occlusion was observed in 4 patients undergoing left internal jagular vein catheterization for haemodialysis. The reported symptom was left arm swelling with no neurological problems. In a cohort of 18 patients undergoing SVC resection for malignancy and major vein reconstruction, 7 patients underwent ligation of the LIV with no neurological symptoms. It was also concluded that reconstruction of the LIV is not consistent with favourable patency. In a case series of 10 patients with central venous obstruction, collateral pathways to conduct efficient venous drainage were mapped. We conclude that division of the LIV is safe in selected patients and operations. Patients will initially have symptoms of central vein obstruction, but these will decrease with conservative management as collaterals form.

Perioperative and long-term outcomes following aortic valve replacement: a population cohort study of 4124 consecutive patients.

OBJECTIVE: Because of increasing life expectancy, more patients require valve replacement for aortic stenosis. We aimed to determine perioperative and long-term outcomes, the factors associated with these and whether they have changed over time. METHODS: We undertook a retrospective cohort study of all 4124 patients, who underwent isolated, primary aortic valve replacement in Scotland between April 1996 and March 2009 inclusive. RESULTS: Annual operations increased by 68%, from 261 to 439. The overall risk of dying within 30 days, 5 years and 10 years was 3.4%, 19.9% and 38.5%, respectively. Over 10 years' follow-up, 4.4% underwent further valve surgery, 7.9% suffered a stroke and 5.3% a myocardial infarction. Age, renal impairment and urgency were predictors of both perioperative and long-term death. Perioperative death was associated with left-ventricular impairment and long-term death with respiratory disease, diabetes and deprivation. Over the 13 years, there was an increase in median age (from 66 to 69 years, p < 0.001), diabetes (from 1.9% to 12.6%, p < 0.001), hypertension (from 26.4% to 56.1%, p < 0.001), cerebrovascular disease (from 3.7% to 9.8%, p < 0.001), respiratory disease (from 6.6% to 9.7%, p = 0.020) and previous myocardial infarction (from 0.6% to 5.8%, p < 0.001), but the risk of perioperative death fell from 6.5% to 3.1% (odds ratio (OR) 0.87, 95% confidence interval (CI) 0.83, 0.92, p < 0.001) per year. CONCLUSIONS: Patients undergoing aortic valve replacement have a poor risk profile. Over time, their numbers, age and co-morbidity have increased. In spite of these, there has been a significant reduction in the risk of perioperative death.

Microsimulation and clinical outcomes analysis support a lower age threshold for use of biological valves.

OBJECTIVE: To characterise contemporary results of aortic valve replacement in relation to type of prosthesis and subsequent competing hazards. METHODS: 5470 procedures in 5433 consecutive patients with aortic valve replacement ± coronary artery bypass grafting (CABG) were studied. Microsimulation of survival and valve-related outcomes was performed based on meta-analysis and patient data inputs, with separate models for age, gender and CABG. Survival was validated against the UK Heart Valve Registry. RESULTS: Patient survival at 1, 5 and 10 years was 90%, 78% and 57%, respectively. The crossover points at which bioprostheses and mechanical prostheses conferred similar life expectancy (LE) was 59 years for men and women (no significant difference between prosthesis types between the ages of 56 and 69 for men, and 58 an 63 for women). The improvement in event-free LE for mechanical valves was greater at younger ages with a crossover point of 66 years for men and 67 years for women. Long-term survival was independently influenced by age, male gender and concomitant CABG, but not by type of prosthesis. In bioprostheses the most common long-term occurrence was structural deterioration. For men aged 55, 65 and 75 at initial operation it had a lifetime incidence of 50%, 30% and 13%, respectively. The simulation output showed excellent agreement with registry data. CONCLUSION: Bioprostheses can be implanted selectively in patients as young as 56 without significant adverse effects on life expectancy, although event-free life expectancy remains significantly lower with bioprostheses up to age of implant of 63.

Reduced LDL-cholesterol levels in patients with coronary artery disease are paralleled by improved endothelial function: An observational study in patients from 2003 and 2007.

OBJECTIVE: Recent guidelines recommend more aggressive lipid-lowering in secondary prevention protocols. We examined whether this resulted in improved endothelial function. METHODS: We studied saphenous vein specimens of patients undergoing surgical coronary revascularisation in 2007 and compared results with those of patients examined in 2003. Endothelium-dependent vasodilation was assessed by relaxation to calcium ionophore A23187, and vascular superoxide production by lucigenin enhanced chemiluminescence. RESULTS: Statin dose increased from 26+/-16 mg/d in 2003 to 37+/-17 mg/d in 2007 (P<0.001), and total (4.0+/-0.9 mmol/L vs 4.8+/-1.0 mmol/L) and LDL-cholesterol levels (2.0+/-0.7 mmol/L vs 3.0+/-0.9 mmol/L) were lower in 2007 compared to 2003 (P<0.001; n=90 each). Endothelium-dependent vasodilation was greater in 2007 (44+/-15%) compared to 2003 (28+/-12%; n=36 each; P<0.001). Vascular superoxide derived from endothelial NO synthase (eNOS) was lower in 2007 than in 2003 (reduction by NG-nitro-L-arginine-methyl ester, 0.29+/-0.21 nmol/(mg min) vs 0.09+/-0.20 nmol/(mg min); P=0.002). In linear regression analysis, LDL-cholesterol levels have been shown to be the major determinant of endothelial function in the combined 2003 and 2007 cohort. CONCLUSION: Intensive lipid-lowering is associated with improved endothelial function and reduced superoxide production from eNOS. Further improvement in vascular function could be achieved by targeting other sources of superoxide including xanthine oxidase.

Stentless Versus Stented Bioprosthetic Aortic Valves: A Consensus Statement of the International Society of Minimally Invasive Cardiothoracic Surgery (ISMICS) 2008.

OBJECTIVE: : The purpose of this consensus conference was to determine whether stentless bioprosthetic valves improve clinical and resource outcomes compared with stented valves in patients undergoing aortic valve replacement, and to outline evidence-based recommendations for the use of stentless and stented bioprosthetic valves in adult aortic valve replacement. METHODS: : Before the consensus conference, the best available evidence was reviewed in that systematic reviews, randomized trials, and nonrandomized trials were considered in descending order of validity and importance. At the consensus conference, evidence-based statements were created, and consensus processes were used to determine the ensuing recommendations. The American Heart Association/American College of Cardiology system was used to label the level of evidence and class of recommendation. RESULTS AND RECOMMENDATIONS: : Seventeen randomized studies published in 23 articles involving 1317 patients, and 14 nonrandomized trial published in 18 articles involving 2485 patients were included in the meta-analysis and consensus conference. All randomized trials inserted the stentless bioprosthetic valves in the subcoronary configuration. The consensus panel agreed upon the following statements and recommendations in patients undergoing aortic valve replacement:Because there were no randomized control trial comparing subcoronary stentless prosthetic valve and root replacement, the following recommendations are derived from expert opinion:

Stentless versus stented bioprosthetic aortic valves: a systematic review and meta-analysis of controlled trials.

OBJECTIVE: : This meta-analysis sought to determine whether stentless bioprosthetic valves improve clinical and resource outcomes compared with stented valves in patients undergoing aortic valve replacement. METHODS: : A comprehensive search was undertaken to identify all randomized and nonrandomized controlled trials comparing stentless to stented bioprosthetic valves in patients undergoing aortic valve replacement available up to March 2008. The primary outcomes were clinical and resource outcomes in randomized controlled trial (RCT). Secondary outcomes clinical and resource outcomes in nonrandomized controlled trial (non-RCT). Odds ratios (OR), weighted mean differences (WMD), or standardized mean differences and their 95% confidence intervals (CI) were analyzed as appropriate. RESULTS: : Seventeen RCTs published in 23 articles involving 1317 patients, and 14 non-RCTs published in 18 articles involving 2485 patients were included in the meta-analysis. For the primary analysis of randomized trials, mortality for stentless versus stented valve groups did not differ at 30 days (OR 1.36, 95% CI 0.68-2.72), 1 year (OR 1.01, 95% CI 0.55-1.85), or 2 to 10 years follow-up (OR 0.82, 95% CI 0.50-1.33). Aggregate event rates for all-cause mortality at 30 days were 3.7% versus 2.9%, at 1 year were 5.5% versus 5.9% and at 2 to 10 years were 17% versus 19% for stentless versus stented valve groups, respectively. Stroke or neurologic complications did not differ between stentless (3.6%) and stented (4.0%) valve groups. Risk of prosthesis-patient mismatch was numerically lower in the stentless group (11.0% vs. 31.3%, OR 0.30, 95% CI 0.05-1.66), but this parameter was reported in few trials and did not reach statistical significance. Effective orifice area index was significantly greater for stentless aortic valve compared with stented valves at 30 days (WMD 0.12 cm/m), at 2 to 6 months (WMD 0.15 cm/m), and at 1 year (WMD 0.26 cm/m). Mean gradient at 1 month was significantly lower in the stentless valve group (WMD -6 mm Hg), at 2 to 6 month follow-up (WMD -4 mm Hg,), at 1 year follow-up (WMD -3 mm Hg) and up to 3 year follow-up (WMD -3 mm Hg) compared with the stented valve group. Although the left ventricular mass index was generally lower in the stentless group versus the stented valve group, the aggregate estimates of mean difference did not reach significance during any time period of follow-up (1 month, 2-6 months, 1 year, and 8 years). CONCLUSIONS: : Evidence from randomized trials shows that subcoronary stentless aortic valves improve hemodynamic parameters of effective orifice area index, mean gradient, and peak gradient over the short and long term. These improvements have not led to proven impact on patient morbidity, mortality, and resource-related outcomes; however, few trials reported on clinical outcomes beyond 1 year and definitive conclusions are not possible until sufficient evidence addresses longer-term effects.

Moderate ischemic mitral regurgitation: to treat or not to treat?

There is consensus of opinion that patients with moderately severe to severe (grade 3+ or 4+) ischemic mitral regurgitation (IMR) should undergo mitral valve surgery at the time of coronary artery bypass grafting (CABG), while trace to mild (grade 1+) IMR can probably be left alone. However, the management of moderate (grade 2+) IMR continues to be a subject of constant debate and controversy. In particular, as techniques of valvular repair continue to be refined; many surgeons have advocated mitral valve repair and concomitant CABG for these patients. Others, however, have continued to treat these patients with revascularization alone and close postoperative observation of the mitral valve. In their opinion, degree of concomitant mitral valve dysfunction in this group of patients does not justify the increased operative risks associated with simultaneous mitral valve correction. We are currently practicing in an era of evidence-based medicine (EBM) in which clinical decision-making has to be guided by current best available evidence from scientific, clinical studies. This review article attempts to tackle this controversial issue and find the best approach of dealing with moderate IMR at the time of CABG by evaluating current best available evidence.