MRI-based strain measurements reflect morphological changes following myocardial infarction: A study on the UK Biobank cohort.

In a porcine experimental model of myocardial infarction, a localised, layer-specific, circumferential left ventricular strain metric has been shown to indicate chronic changes in ventricular function post-infarction more strongly than ejection fraction. This novel strain metric might therefore provide useful prognostic information clinically. In this study, existing clinical volume indices, global strains, and the novel, layer-specific strain were calculated for a large human cohort to assess variations in ventricular function and morphology with age, sex, and health status. Imaging and health data from the UK Biobank were obtained, including healthy volunteers and those with a history of cardiovascular illness. In total, 710 individuals were analysed and stratified by age, sex and health. Significant differences in all strain metrics were found between healthy and unhealthy populations, as well as between males and females. Significant differences in basal circumferential strain and global circumferential strain were found between healthy males and females, with males having smaller absolute values for both (all p ≤ 0.001). There were significant differences in the functional variables left ventricular ejection fraction, end-systolic volume, end-systolic volume index and mid-ventricular circumferential strain between healthy and unhealthy male cohorts aged 65-74 (all p ≤ 0.001). These results suggest that whilst regional circumferential strains may be useful clinically for assessing cardiovascular health, care must be taken to ensure critical values are indexed correctly to age and sex, due to the differences in these values observed here.

Surgical transcatheter valve implantation: The more pathways, the better.

Transcatheter aortic valve implantation (TAVI) is rapidly spreading across the world with the endorsement of the cardiological community and the supporting results of randomized controlled trials. However, TAVI-related complications like aortic dissection, aortic valvular rupture, or left ventricle perforation are still potentially catastrophic.

Surgical treatment of a giant right coronary aneurysm following coronary stent fracture.

BACKGROUND: Coronary artery aneurysm represents a challenging and potentially fatal disease. AIM AND MATERIAL METHODS: We present the case of a giant right coronary artery aneurysm treated surgically after percutaneous intervention and fracture of the stent. RESULTS AND DISCUSSION: The aneurism was opened and the coronary ligated proximally and distally. It was not possible to re-established continuity of the coronary artery or perform a bypass graft. An early surgical strategy would have re-established blood flow in the involved coronary artery and avoided chronic ischemia of the supplied myocardial territory.

Acute coronary occlusion after surgical replacement of the aortic valve treated with emergency off-pump coronary artery bypass grafting.

Acute coronary occlusion after surgical replacement of the aortic valve is a rare but potentially fatal event. Due to its rarity, there is no univocal treatment with the percutaneous approach being the most commonly used for its promptness and ease of use. Only a few cases have been treated with coronary artery bypass grafting (CABG) and, to the best of our knowledge, none has been reported with the use of off-pump CABG (OPCABG). Here we describe the case of acute coronary occlusion of the circumflex artery immediately after surgical replacement of the aortic valve in a 79-year-old patient. The occlusion was promptly diagnosed and treated with interval emergency balloon angioplasty followed by OPCABG of the circumflex artery. The patient made a full recovery and was discharged home 12 days after the surgery.

Benefits of mitral valve repair over replacement in the elderly: a systematic review and meta-analysis.

OBJECTIVES: Mitral valve (MV) repair has demonstrated excellent short- and long-term outcomes, however, its merit in the elderly population is still debated. We conducted a meta-analysis of studies that have compared the MV repair to replacement in the elderly population. METHODS: A systematic literature search was conducted for any study published on MV surgery on elderly patients (≥75 years old). A pooled risk-ratio meta-analysis was done to evaluate short-term mortality, postoperative complications, surgical timings, and long-term survival rates. RESULTS: A total of nine retrospective observational studies were included in the quantitative meta-analysis. Pooled meta-analysis showed a reduced risk of short-term mortality for the MV repair group (risk ratio [RR] = 0.41 [0.24-0.71], p-value = .005). Postoperative neurological complications were in favor of repair, although not significantly (RR = 0.49 [0.21-1.11], p-value = .07). Operative timings (cardiopulmonary bypass and crossclamp time) were not different between the groups although no data were available on the complexity of the repairs. Long-term survival rates were in favor of the repairs (pooled treatment effect of -0.47 [-0.64; -0.29], p = .005). CONCLUSIONS: MV surgery is a safe and effective procedure for the elderly. MV repair demonstrated better short-term outcomes compared to replacement. Long-term survival rates are significantly better after repair.

The impact of patient-prosthesis mismatch on early and long-term survival after aortic replacement with the Edwards Perimount valve: A propensity score-matched analysis.

BACKGROUND: To investigate the impact of severe patient-prosthesis mismatch (PPM) related to the Edwards Lifesciences Perimount (EP) bioprosthesis in the aortic position on early in-hospital outcomes and long-term survival. METHODS: A total of 5964 consecutive patients underwent aortic valve replacement at the Bristol Heart Institute between 1998 and 2014, 2667 representing the cohort of this study received EP. PPM was defined severe as EOAi < 0.65 cm2 /m2 . To minimize bias, propensity score matching was conducted and two groups A and B (without and with severe PPM) of 320 patients with similar preoperative characteristics were matched. We assessed early in-hospital outcomes including CVA, re-exploration for bleeding, low cardiac output, wound infection, acute renal injury, length of hospital stay, and long-term survival for both groups in unmatched and matched populations. RESULTS: In the unmatched analysis, 18.3% of patients had severe PPM. Severe PPM was not associated with increased in-hospital mortality (4.5% vs. 2.9%, respectively, p = .09) or any other early adverse outcomes except increased length of hospital stay (10.57 ± 8.2 vs. 11.7 ± 9.4, respectively, p = .01). Long-term survival differed significantly between groups at 2 and 8 years (91.8% vs. 91.4% and 60.5% vs. 55.7%, respectively, p = .02). Matched analysis showed no differences between the groups in early health outcomes and overall survival at 2 and 8 years was also similar (89.7% vs. 91% and 57.3% vs. 58%, group A vs. B, respectively p = .9). CONCLUSION: Presence of PPM does not seem to affect early in-hospital outcomes or late survival when using EP in patients undergoing aortic valve replacement.

Saphenous vein graft disease, pathophysiology, prevention, and treatment. A review of the literature.

BACKGROUND: The saphenous vein remains the most frequently used conduit for coronary artery bypass grafting, despite reported unsatisfactory long-term patency rates. Understanding the pathophysiology of vein graft failure and attempting to improve its longevity has been a significant area of research for more than three decades. This article aims to review the current understanding of the pathophysiology and potential new intervention strategies. METHODS: A search of three databases: MEDLINE, Web of Science, and Cochrane Library, was undertaken for the terms "pathophysiology," "prevention," and "treatment" plus the term "vein graft failure." RESULTS: Saphenous graft failure is commonly the consequence of four different pathophysiological mechanisms, early acute thrombosis, vascular inflammation, intimal hyperplasia, and late accelerated atherosclerosis. Different methods have been proposed to inhibit or attenuate these pathological processes including modified surgical technique, topical pretreatment, external graft support, and postoperative pharmacological interventions. Once graft failure occurs, the available treatments are either surgical reintervention, angioplasty, or conservative medical management reserved for patients not eligible for either procedure. CONCLUSION: Despite the extensive amount of research performed, the pathophysiology of saphenous vein graft is still not completely understood. Surgical and pharmacological interventions have improved early patency and different strategies for prevention seem to offer some hope in improving long-term patency.

Impact of Body Mass Index on Short- and Long-Term Outcomes After Isolated First-Time Surgical Aortic Valve Replacement for Aortic Stenosis.

OBJECTIVE: To ascertain whether body mass index (BMI) has a clinical effect on short- and long-term postoperative outcomes after surgical aortic valve replacement in patients with severe aortic stenosis. DESIGN: Single-center, retrospective study. SETTING: Tertiary referral hospital. PARTICIPANTS: The study comprised 1,561 patients who underwent isolated first-time aortic valve replacement between 2005 and 2012. INTERVENTIONS: Fourteen underweight patients were removed from the analysis. The remaining patients were divided into the following 4 groups according to their BMI: 418 as normal weight (≥18.5 to <25 kg/m2), 629 as overweight (≥25 to <30 kg/m2), 342 as obese (≥30 to <35 kg/m2), and 158 as very obese (≥35 kg/m2). Early mortality and postoperative complications were compared, and long-term survival rates were investigated. MEASUREMENT AND MAIN RESULTS: Thirty-day mortality was higher in the normal weight group but did not reach statistical significance (p = 0.054), and the incidence of postoperative complications was not different for cerebrovascular accident (p = 0.70), re-sternotomy for bleeding (p = 0.17), sternal wound infection (p = 0.07), and dialysis (p = 0.07). With a mean follow-up time of 4.92 ± 2.82 years, survival rate was better in the overweight group. A Cox proportional hazard model found BMI inversely correlated with long-term mortality when analyzed in a univariable fashion (hazard ratio 0.95; p = 0.009), but this apparent protective effect disappeared when adjusted for preoperative covariates (hazard ratio 0.98, 95% confidence interval 0.96-1.004; p = 0.12). CONCLUSION: Once adjusted for preoperative characteristics, obesity does not represent an independent predictor for long-term survival rates. There was a higher incidence of 30-day mortality in the normal weight group compared with the overweight and very obese groups. The incidence of deep sternal wound infection was higher in very obese patients.

Effectiveness and Safety of Aprotinin Use in Thoracic Aortic Surgery.

OBJECTIVE: To determine the effectiveness and safety of aprotinin use in adult patients undergoing thoracic aortic surgery. DESIGN: Single-center, retrospective study. SETTING: All cases performed at a single university hospital. PARTICIPANTS: Between January 2004 and December 2014, 846 adult patients underwent thoracic aortic surgery. Due to missing or duplicated data on primary outcomes, 314 patients were excluded. The final sample of 532 patients underwent surgery on the thoracic aorta. INTERVENTIONS: The patients were divided in the following 2 groups: 107 patients (20.1%) received aprotinin during the surgery, which represented the study group, whereas the remaining 425 patients (79.9%) underwent surgery without the use of aprotinin. MEASUREMENTS AND MAIN RESULTS: To adjust for patient selection and preoperative characteristics, a propensity score-matched analysis was conducted. Mean total blood loss at 12 hours after surgery was similar between the 2 groups. The blood product transfusion rates did not differ in the 2 groups, except for the rate of fresh frozen plasma transfusion being significantly higher in the aprotinin group. Re-exploration for bleeding and the incidence of a major postoperative bleeding event were similar between the groups. Rates of in-hospital mortality, renal failure, and cerebrovascular accidents did not show any statistically significant difference. Aprotinin did not represent a risk factor for mortality over the long term (hazard ratio 1.14, 95% confidence interval 0.62-2.08, p = 0.66). CONCLUSIONS: The use of aprotinin demonstrated a limited effect in reducing postoperative bleeding and prevention of major bleeding events. Aprotinin did not adversely affect early outcomes and long-term survival.

Intramyocardial immunomodulation with human CD16+ monocytes to treat myocardial infarction in pig: a blind randomized preclinical trial.

Background: Human CD16+ monocytes (hCD16+ Ms) have proangiogenic properties. We assessed the feasibility, safety and efficacy of hCD16+ Ms in a porcine model of myocardial infarction (MI). Methods and results: A total of 27 female Large White pigs underwent MI with reperfusion and cardiac magnetic resonance (CMR). Five days later, animals received intramyocardial injections of hCD16+ Ms in saline (n = 13) or saline only (n = 14). hCD16+ Ms were selected from leucocyte cones. Feasibility/safety endpoints included injury at injected sites, malignant arrhythmias, cancer, haematoma, left ventricular (LV) dilatation, troponin release and downstream organ injury. Co-primary efficacy outcome included LV scar and ejection fraction (LVEF) at 30-day post-injections by CMR. Immunohistochemistry included neo-angiogenesis, fibrosis, markers of myofibroblast and inflammation. Four animals were excluded before injections due to untreatable malignant arrhythmias or lung injury. Median cell number and viability were 48.75 million and 87%, respectively. No feasibility/safety concerns were associated with the use of hCD16+ Ms. The LV scar dropped by 14.5gr (from 25.45 ± 8.24 to 10.8 ± 3.4 gr; -55%) and 6.4gr (from 18.83 ± 5.06 to 12.4 ± 3.9gr; -30%) in the hCD16+ Ms and control groups, respectively (p = 0.015). The 30-day LVEF did not differ between groups, but a prespecified sub-analysis within the hCD16+ Ms group showed that LVEF was 2.8% higher and LV scar 1.9gr lower in the subgroup receiving a higher cell dose. Higher tissue levels of neo-angiogenesis, myofibroblast and IL-6 and lower levels of TGF-ß were observed in the hCD16+ Ms group. Conclusions: The use of hCD16+ Ms in acute MI is feasible, safe and associated with reduced LV scar size, increased tissue levels of neo-angiogenesis, myofibroblasts and IL-6 and reduced pro-fibrotic TGF-ß at 30-day post-injections. A higher cell dose might increase the LVEF effect while reducing scar size, but this warrants validation in future studies.

Validation of the German Registry for Acute Aortic Dissection Type A Score in predicting 30-day mortality after type A aortic dissection surgery.

OBJECTIVES: No reliable scores are available to predict mortality following surgery for type A acute aortic dissection (TAAAD). Recently, the German Registry of Acute Aortic Dissection Type A (GERAADA) score has been developed. We aim to compare how the GERAADA score performs in predicting operative mortality for TAAAD to the European System for Cardiac Operative Risk Evaluation (EuroSCORE) II. METHODS: We calculated the GERAADA score and EuroSCORE II in patients who underwent TAAAD repair at the Bristol Heart Institute. As there are no precise criteria to calculate the GERAADA score, we used 2 methods: a Clinical-GERAADA score, which evaluated malperfusion with clinical and radiological evidence, and a Radiological-GERAADA score, where malperfusion was assessed by computed tomography scan alone. RESULTS: 207 consecutive patients had surgery for TAAAD, and the observed 30-day mortality was 15%. The Clinical-GERAADA score showed the strongest discriminative power with an area under the curve (AUC) of 0.80 [95% confidence interval (CI) 0.71-0.89], while the Radiological-GERAADA score had an AUC of 0.77 (95% CI 0.67-0.87). EuroSCORE II showed acceptable discriminative power with an AUC of 0.77 (95% CI 0.67-0.87). CONCLUSIONS: Clinical GERAADA score performed better than the other scores and it is specific and easy to use in the context of a TAAAD. Further validation of the new criteria for malperfusion is needed.

Human coronary microvascular contractile dysfunction associates with viable synthetic smooth muscle cells.

AIMS: Coronary microvascular smooth muscle cells (SMCs) respond to luminal pressure by developing myogenic tone (MT), a process integral to the regulation of microvascular perfusion. The cellular mechanisms underlying poor myogenic reactivity in patients with heart valve disease are unknown and form the focus of this study. METHODS AND RESULTS: Intramyocardial coronary micro-arteries (IMCAs) isolated from human and pig right atrial (RA) appendage and left ventricular (LV) biopsies were studied using pressure myography combined with confocal microscopy. All RA- and LV-IMCAs from organ donors and pigs developed circa 25% MT. In contrast, 44% of human RA-IMCAs from 88 patients with heart valve disease had poor (<10%) MT yet retained cell viability and an ability to raise cytoplasmic Ca2+ in response to vasoconstrictor agents. Comparing across human heart chambers and species, we found that based on patient medical history and six tests, the strongest predictor of poor MT in IMCAs was increased expression of the synthetic marker caldesmon relative to the contractile marker SM-myosin heavy chain. In addition, high resolution imaging revealed a distinct layer of longitudinally aligned SMCs between ECs and radial SMCs, and we show poor MT was associated with disruptions in these cellular alignments. CONCLUSION: These data demonstrate the first use of atrial and ventricular biopsies from patients and pigs to reveal that impaired coronary MT reflects a switch of viable SMCs towards a synthetic phenotype, rather than a loss of SMC viability. These arteries represent a model for further studies of coronary microvascular contractile dysfunction.

Clinical Outcomes and OCT Analysis After Culotte Stenting With 2nd- and 3rd-Generation Everolimus-Eluting Stents: Two-Year Follow-Up of the CELTIC Bifurcation Study.

PURPOSE: The aim of this study was to provide 2-year clinical outcomes for patients with Medina 1,1,1 bifurcation lesions treated with a culotte technique, comparing Synergy and Xience drug eluting stent (DES) platforms. A sub-group analysis of 9-month Optical Coherence Tomography (OCT) was performed to assess stent healing. METHODS: A total of 170 patients with non-left main stem Medina 1,1,1 lesions, were randomized to treatment with Synergy or Xience DES. The primary outcome was a composite of death, myocardial infarction, stroke, target vessel failure, stent thrombosis and angiographic restenosis. Qualitative and quantitative analyses of 30 bifurcations were carried out on OCT images taken at 9-month follow-up. RESULTS: After 2 years, the primary outcome had occurred in 17.7% of patients in the Synergy group and 18.8% of patients in the Xience group. The non-inferiority test was met (p = 0.0055). MACCE occurred in 7.3% of all patients by 2 years. OCT analysis found smaller stent and lumen areas in patients treated with Synergy stents. There was a higher proportion of malapposed struts in patients treated with Xience stents. CONCLUSIONS: The first report of the CELTIC bifurcation study demonstrated a low MACCE rate after 9 months. There was little accrual of events after this timepoint. There was no difference in clinical outcomes between the platforms tested. OCT analysis demonstrated excellent healing of both platforms.

Effective decellularisation of human saphenous veins for biocompatible arterial tissue engineering applications: Bench optimisation and feasibility in vivo testing.

Human saphenous vein (hSV) and synthetic grafts are commonly used conduits in vascular grafting, despite high failure rates. Decellularising hSVs (D-hSVs) to produce vascular scaffolds might be an effective alternative. We assessed the effectiveness of a detergent-based method using 0% to 1% sodium dodecyl sulphate (SDS) to decellularise hSV. Decellularisation effectiveness was measured in vitro by nuclear counting, DNA content, residual cell viability, extracellular matrix integrity and mechanical strength. Cytotoxicity was assessed on human and porcine cells. The most effective SDS concentration was used to prepare D-hSV grafts that underwent preliminary in vivo testing using a porcine carotid artery replacement model. Effective decellularisation was achieved with 0.01% SDS, and D-hSVs were biocompatible after seeding. In vivo xeno-transplantation confirmed excellent mechanical strength and biocompatibility with recruitment of host cells without mechanical failure, and a 50% patency rate at 4-weeks. We have developed a simple biocompatible methodology to effectively decellularise hSVs. This could enhance vascular tissue engineering toward future clinical applications.

Adult coronary artery bypass grafting by congenital surgeons-a propensity matched analysis.

OBJECTIVES: Surgical myocardial revascularization will be increasingly needed in adult patients with congenital heart disease. We investigated the results of coronary artery bypass grafting (CABG) performed on adults by congenital cardiac surgeons at our institution. METHODS: We conducted a retrospective, single-centre study. Adults undergoing isolated or combined CABG from 2004 to 2017 were included. Early and late outcomes were analyzed for the whole cohort. Furthermore, a propensity matched analysis was conducted comparing the results of isolated CABG between congenital and adult surgeons. RESULTS: A total of 514 and 113 patients had isolated and combined CABG for acquired heart disease, respectively. A total of 33 patients had myocardial revascularization at the time of surgery for congenital heart disease. Overall early mortality was 1.2%, the rate of re-exploration for bleeding was 4.5%, and an internal mammary artery to left anterior descending artery graft was used in 85.6% patients. One-year survival was 97.5% (96.2-98.8%), and 5-year survival was 88.0% (84.8-91.3%). After propensity matching (468 pairs), early mortality (0.6% vs 1.2%, P = 0.51), re-exploration for bleeding (3.6% vs 3.0%, P = 0.72), use of internal mammary artery to left anterior descending artery graft (92.7% vs 91.9%, P = 0.70) and late survival did not differ between congenital surgeons and adult surgeons, respectively. CONCLUSIONS: Surgical myocardial revascularization can be required for adult congenital patients in a broad spectrum of clinical situations. Despite lower volumes, congenital cardiac surgeons perform CABG safely and with results that are comparable to those of the adult surgeons at our centre.

Combined Degenerative Mitral Valve and Coronary Surgery: Early Outcomes and 10-Year Survival.

BACKGROUND: This study investigated the impact of combined degenerative mitral valve (DMV) and coronary artery bypass grafting (CABG+DMV) surgery vs DMV surgery only on in-hospital health outcome and 10-year survival. METHODS: We identified 745 patients with DMV disease. Of these, 186 (24.9%) were affected also by coronary disease and underwent combined DMV+CABG. They were compared with the remaining 559 patients receiving DMV-only surgery in in-hospital and 1-, 5-, and 10-year survival. We evaluated a short-term composite outcome of hospital mortality, acute kidney injury, cerebrovascular events, and low cardiac output requiring postoperative use of intraaortic balloon pump. In addition, we assessed mitral valve repair rates over time and their correlation with long-term survival. To minimize bias, we conducted a propensity score-matching analysis. RESULTS: DMV+CABG surgery was associated with a similar incidence of the composite end point compared with DMV-only surgery in the unmatched analysis (6.5% vs 5.4%, P = .71) and matched analysis (7.5% vs 8.2%, P = .82). The 10-year survival was 70.5% vs 68.6% (P = .07) for the unmatched analysis and 64.6% vs 62.5% (P = .9) for the matched analysis, DMV+CABG vs DMV-only, respectively. Mitral valve repair had a beneficial effect on short-term outcomes and long-term mortality rates, regardless the presence of concomitant coronary surgery. CONCLUSIONS: Combined DMV+CABG surgery is a very effective surgical treatment with high mitral valve repair rate. Early in-hospital outcome and long-term survival are comparable with DMV-only surgery. In these combined procedures, mitral valve repair is associated with better long-term survival.

Isolated aortic insufficiency valve repair with external ring annuloplasty: a standardized approach.

OBJECTIVES: Aortic valve (AV) insufficiency with normal root and ascending aorta is most frequently treated by valve replacement with significant prosthetic-related complications and reduced life expectancy. We compared the outcomes of a new standardized isolated AV repair approach using an external aortic annuloplasty ring at the subvalvular level (single ring annuloplasty) and the role of an additional supravalvular ring at the sinotubular junction (double ring annuloplasty). METHODS: Single centre data were collected from the Aortic Valve Insufficiency and ascending aorta Aneurysm InternATiOnal Registry (AVIATOR) between 2003 and 2017. A total of 93 patients (56 single ring and 37 double ring) underwent isolated AV repair. RESULTS: The overall 30-day mortality rate and the need for a permanent pacemaker were 1% and 2%, respectively. The overall survival rate at 6 years was similar for sex- and age-matched members of the general population (89% vs 95%; P = 0.1) and did not differ between the double and single ring groups (82% vs 93%; P = 0.4) at 6 years. There were no thromboembolic or bleeding events in the entire cohort. However, at 6 years, the cumulative incidence of valve-related reintervention was 26% in the single ring annuloplasty group compared to 3% in the double ring annuloplasty (P = 0.02) group. Similarly, at 6 years, the cumulative incidence of moderate-to-severe (>2) aortic insufficiency was 30% in the single ring annuloplasty group compared to 0% in the double ring annuloplasty group (P = 0.007). CONCLUSIONS: Standardized AV repair with external ring annuloplasty has a survival rate similar to that of the general population. The additional stabilization of the sinotubular junction with a second supravalvular ring (double ring annuloplasty) is associated with better outcomes compared to single subvalvular annuloplasty. It can be considered as a first line intervention for patients with isolated aortic insufficiency and pliable leaflets.

Design, development, testing at ISO standards and in vivo feasibility study of a novel polymeric heart valve prosthesis.

Clinically available prosthetic heart valves are life-saving, but imperfect: mechanical valves requiring anticoagulation therapy, whilst bioprosthetic valves have limited durability. Polymer valves offer the prospect of good durability without the need for anticoagulation. We report the design and development of a polymeric heart valve, its bench-testing at ISO standards, and preliminary extra-vivo and in vivo short-term feasibility. Prototypes were manufactured by injection moulding of styrenic block copolymers to achieve anisotropic mechanical properties. Design was by finite element stress-strain modelling, which has been reported previously, combined with feedback from bench and surgery-based testing using various combinations of materials, valve geometry and processing conditions. Bench testing was according to ISO 5840:2015 standards using an in vitro cardiovascular hydrodynamic testing system and an accelerated fatigue tester. Bench comparisons were made with a best-in-class bio-prosthesis. Preliminary clinical feasibility evaluations included extra-vivo and short-term (1-24 hours) in vivo testing in a sheep model. The optimised final prototype met the requirements of ISO standards with hydrodynamic performance equivalent to the best-in-class bioprosthesis. Bench durability of greater than 1.2 billion cycles (30 years equivalent) was achieved (still ongoing). Extra-vivo sequential testing (n = 8) allowed refinement of external diameter, 3D shape, a low profile, flexibility, suturability, and testing of compatibility to magnetic resonance imaging and clinical sterilisation. In vivo short-term (1-24 hours) feasibility (n = 3) confirmed good suturability, no mechanical failure, no trans-valvular regurgitation, competitive trans-valvular gradients, and good biocompatibility at histopathology. We have developed and tested at ISO standards a novel prosthetic heart valve featuring competitive bench-based hydrodynamics and durability, well beyond the ISO requirements and comparable to a best-in-class bioprosthesis. In vivo short-term feasibility testing confirmed preliminary safety, functionality and biocompatibility, supporting progression to a long-term efficacy trial.

Correction: Design, development, testing at ISO standards and in vivo feasibility study of a novel polymeric heart valve prosthesis.

Correction for 'Design, development, testing at ISO standards and in vivo feasibility study of a novel polymeric heart valve prosthesis' by Joanna R. Stasiak et al., Biomater. Sci., 2020, DOI: .