Bristol Heart Institute Research Articles

Linked Cardiology records of the children in the Avon Longitudinal Study of Parents and Children (ALSPAC) From The University Hospitals Bristol and Weston NHS Foundation Trust (UHBW) Heart-Suite (HS) dataset

This data note describes the linked records of the index children of the Avon Longitudinal Study of Parents and Children (ALSPAC) birth cohort study found within the cardiology records of the University Hospitals Bristol and Weston NHS Foundation Trust (UHBW) Heart-Suite (HS) dataset. It is important to note that ALSPAC only provided details of participants alive after one year of age, and who had allowed their data to be used for linking, which may have excluded a non-trivial, unknown, quantity from linking to the Bristol tertiary cardiac clinic database. These records were extracted from the computerised record system ‘Heart-Suite’ which is maintained by the Bristol Heart Institute (BHI) in UHBW based at Bristol Royal Infirmary (BRI). The Heart-Suite database is the case management system used by the BHI. A data extract was provided by the BHI data team to ALSPAC. The cleaned Heart-Suite records provide a dataset of specialist, clinical records of a subset of the ALSPAC cohort who were referred to the tertiary cardiac team at UHBW. These data can be linked to the wider ALSPAC dataset and made available to approved research users.

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

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. 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. 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). 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.

Outcome Monitoring After Cardiac Surgery (OMACS): a single-centre prospective cohort study of cardiac surgery patients

IntroductionMore than 30 000 cardiac surgery procedures are performed in the UK each year, however, postoperative complications and long-term failure of interventions are common, leading to repeated surgeries. This represents...

The impact of surgical training on early and long-term outcomes after isolated aortic valve surgery.

OBJECTIVESPatients presenting with more comorbidities, requiring more complex cardiac surgical procedures and an increase in public scrutiny are impacting on training programme because of the perceived risk of worse outcomes. Hence, we aimed to provide evidence that trainees as the first operator can achieve comparable results to consultants when performing isolated surgical aortic valve replacement. METHODSFrom 1996 to 2017, 2919 patients underwent surgical aortic valve replacement at the Bristol Heart Institute, operated on by either a consultant (n = 2220) or a trainee (n = 870) as the first operator. Propensity score matching was used to adjust for imbalance in the baseline characteristics of the 2 groups.RESULTSOver a 21-year period, the proportion of trainee cases dropped from 41.5% to 25.9%. No differences in the rates and risk of in-hospital mortality, new cerebrovascular accidents, re-exploration for bleeding, deep sternal wound infection and length of stay were found between patients operated on in the 2 groups. Also, there was a comparable risk of late death between the 2 groups (HR 0.88; 95% CI 0.73–1.06; P = 0.27) and this was present regardless of trainees career level and patients surgical risk based on the EuroSCORE. Finally, we showed an increase in patients risk profile in the latest year but, this was not associated with the worst outcomes when trainees performed the operation.CONCLUSIONSSurgical aortic valve replacement is a safe and reproducible technique and regardless of the patient’s risk profile, and no differences in the outcomes between trainees and consultant cases were found.

Ten minutes with Dr Andy Georgiou, Director of Intensive Care, and Margi Jenkins, Matron for Intensive Care and Outreach at The Royal United Hospitals NHS Trust, Bath, UK

Photograph: R Howman. ### Biography Andy Georgiou has been the director of the Intensive Care Unit at the Royal United Hospital in Bath since 2013 and is an honorary senior...

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.

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. 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. 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). Presence of PPM does not seem to affect early in-hospital outcomes or late survival when using EP in patients undergoing aortic valve replacement.

Quantitative evaluation and comparison of coronary artery characteristics by 3D coronary volume reconstruction

Non-atherosclerotic abnormalities of vessel calibre, aneurysm and ectasia, are challenging to quantify and are often overlooked in qualitative reporting. Utilising a novel 3-dimensional (3D) quantitative coronary angiography (QCA) application, we have evaluated the characteristics of normal, diabetic and aneurysmal or ectatic coronary arteries. We selected 131 individuals under 50 years-of-age, who had undergone coronary angiography for suspected myocardial ischaemia between 1st January 2011 and 31st December 2015, at the Bristol Heart Institute, Bristol, UK. This included 42 patients with angiographically normal coronary arteries, 36 diabetic patients with unobstructed coronaries, and 53 patients with abnormal coronary dilatation (aneurysm and ectasia). A total of 1105 coronary segments were analysed using QAngio XA 3D (Research Edition, Medis medical imaging systems, Leiden, The Netherlands). The combined volume of the major coronary arteries was significantly different between each group (1240 ± 476 mm3 diabetic group, 1646 ± 391 mm3 normal group, and 2072 ± 687 mm3 abnormal group). Moreover, the combined coronary artery volumes correlated with patient body surface area (r = 0.483, p < 0.01). Inter-observer variability was assessed and intraclass correlation coefficient of the total coronary artery volume demonstrated a low variability of 3D QCA (r = 0.996, p < 0.001). Dedicated 3D QCA facilitates reproducible coronary artery volume estimation and allows discrimination of normal and diseased vessels.

Trend in morbidity and mortality in surgical aortic valve replacement: a retrospective, observational, single-centre study.

Continuous improvement in the management of patients undergoing surgical aortic valve replacement (SAVR) may have considerably enhanced surgical outcomes including in-hospital mortality and perioperative complications. We aimed to analyse in-hospital mortality and morbidity trends in patients undergoing SAVR in a single centre to provide insights for future benchmarking for transcatheter aortic valve implantation indications. This was a retrospective study of prospectively collected data from patients undergoing either isolated SAVR or combined with coronary artery bypass grafting (CABG) at the Bristol Heart Institute, UK, from January 2000 to December 2017. Baseline characteristics were extracted and analysed across 3 different eras (2000-2005, 2006-2011 and 2012-2017). Risk-adjusted time trend was obtained from univariate and multivariate logistic regression including all baseline characteristics. A total of 2719 patients (63.2%) underwent isolated SAVR, and 1581 (36.8%) underwent combined CABG and SAVR during the study period. For patients undergoing SAVR, in-hospital mortality decreased from 2.9% in 2000-2005 to 0.7% in 2012-2017 (risk-adjusted time trend 0.0001). Hospital mortality in patients aged 75-79 and ≥80 years decreased from 5.6% and 5.3% to 0.4% and 2.2%, respectively. Mortality after combined SAVR and CABG did not significantly decrease (from 3.9% in 2000-2005 to 3.5% in 2012-2017; risk-adjusted time trend = 0.62). However, in patients aged ≥80 years, index hospitalization mortality showed a decreasing non-significant trend from 9.8% to 4.8%. Our findings support the hypothesis that mortality and morbidity rates following SAVR have significantly improved over the years, including for patients at high risk.

QTc interval in survivors of out of hospital cardiac arrest

BackgroundQTc interval (QTc) prolongation is seen on the post-arrest electrocardiogram (ECG) of many out of hospital cardiac arrest (OHCA) survivors. It remains unclear whether this is a transient phenomenon or a manifestation of an underlying arrhythmic substrate.This observational study assessed the trend of QTc in an unselected group of patients presenting with OHCA. We sought to identify any relationship between QTc, gender and aetiology of arrest. We observed whether targeted temperature management (TTM) is associated with malignant arrhythmia. MethodWe analysed 60 patients presenting with OHCA to the Bristol Heart Institute during a 20-month period. We measured QTc on admission and assessed for persistence, development and resolution of prolongation at up to 5 time points post-OHCA. Aetiology of arrest was divided into coronary, non-coronary or primary arrhythmic to investigate for patterns in QTc behaviour. Results81.7% (49/60) of arrests were attributed to an acute coronary event. 55% (33/60) had QTc prolongation on admission, of which 79% resolved. There were no significant differences in QTc behaviour by aetiology.One patient presenting with a normal QTc, developed prolongation during admission and received a genetic diagnosis of Long QT Syndrome. TTM was employed in 57/60, with no increased incidence of malignant arrhythmia. ConclusionsProlonged QTc on admission does not imply a primary arrhythmic aetiology and resolves in the majority pre-discharge. However, an initial normal QTc post-OHCA does not preclude a diagnosis of Long QT syndrome, highlighting the importance of thorough investigations in these patients. TTM appears safe from a cardiac perspective.

Developing a cardiac surgery unit in the Caribbean: A reflection.

Access to specialized cardiac surgery is a problem in emerging countries. Here, we reflect on the approach we used to establish a cardiac surgery unit in Trinidad and Tobago. The program started in 1993 with monthly visits by a team from Bristol Heart Institute. A group of local doctors, nurses, and perfusionists were identified for training, and a senior nurse moved to the island to start a teaching program. The visiting support was gradually reduced, and the local team gained independence in managing the service in 2006. The initial low volume surgery increased to around 380 cases a year with the implementation of comprehensive service in 2006. Most patients required coronary artery bypass graft (CABG). In-hospital mortality declined from 5% in the nascent years to below 2% thereafter. In the last 5 years (2015-2019), 1764 patients underwent surgery (mean age 59.6 ± 10.8 years, 66% male). The majority were East-Indian-Caribbean (79.1%) or Afro-Caribbean (16.7%), half had diabetes, and two-thirds hypertension (EuroScore II 1.8 ± 1.9). The majority (1363 patients) underwent CABG (99.5% off-pump; conversion to on-pump 1.5%). The mean number of grafts was 2.5 ± 0.7 with 98.5% and 23.1% receiving one and two or more arterial grafts, respectively. In-hospital mortality was 1.1%, re-exploration for bleeding 2%, stroke 0.1%, mediastinitis 0.2%. The length of the postoperative hospital stay was 5.8 ± 2 days. Frequent outside visits complemented by training in an overseas center, and transfer of knowledge proved to be an effective strategy to develop a cardiac surgery unit in an emerging country with results comparable to accepted international standards.

Long-term survival after off-pump versus on-pump coronary artery bypass graft surgery. Does completeness of revascularization play a role?

BackgroundWe sought to compare the incidence of incomplete revascularization (IR) and long-term survival (up to 20years) after off-pump (OPCAB) versus on-pump (ONCAB) coronary artery bypass in a high OPCAB volume centre where OPCAB was introduced in 1996 and has become the preferred strategy over the years. Methods and resultsFrom 1996 to 2015 a total of 7,427 OPCAB and 7128 ONCAB procedures were performed at Bristol Heart Institute, United Kingdom. We obtained 5423 propensity matched pairs for final comparison. Mixed effect Cox model accounting for clustering due to different surgeon was used to investigate the treatment effect on mortality. ResultsOPCAB was associated with higher rate of incomplete revascularization 13.3% versus 6.7%; P<0.0001). Mean follow-up time was 7.8±4.6year [max 17.3]. At 12years OPCAB was associated with a marginal but significant +3% increase in overall mortality (67.4%[95%CI 65.8–69.1] vs 64.4%[95%CI 62.7–66.2]; stratified log-rank P=0.03). When compared to ONCAB with complete revascularization, OPCAB with IR (HR 1.74;95%CI 1.53–1.99; P<0.001) and ONCAB with IR (HR 1.29; 95%CI 1.06–1.57; P=0.01) but not OPCAB with complete revascularization (HR 1.02;95%CI 0.94–1.11; P=0.63) were associated with increased risk of late mortality. ConclusionDespite completeness of revascularization was achieved in the majority of OPCAB cases, OPCAB remained associated with a significantly higher rate of incomplete revascularization. This translated into a marginal but significant reduction in late survival rates after OPCAB when compared to ONCAB.

Diagnosing myocarditis with magnetic resonance

Bristol Heart Institute, University of Bristol, Bristol, UK Correspondence to Chiara Bucciarelli-Ducci, PhD, Wolters Kluwer, London, UK E-mail: [email protected] Received 12 September, 2016 Accepted 14 September, 2016

How to measure vessel flow with CMR phase contrast imaging

Background Accurately measuring blood flow with CMR is paramount in patients with valvular disease. These flow measurements are important components of a CMR report and provide the referring clinicians with valuable information in which to base further clinical management. This poster presents a guide on how to measure blood flow accurately based on our experience at the Bristol Heart Institute.

T2 values of the acutely infarcted myocardium following primary PCI: the relationship with infarct characteristics and gadolinium extracellular volume of distribution

Background T2 mapping has been shown to detect myocardial oedema as assessed by histology in animals, and is a promising sequence to detect the area at risk in STEMI. The specific cut off value to identify abnormal myocardium in STEMI has not been identified nor have the effects of infarct characteristics on T2 valves. The extra cellular volume fraction (ECV) has been validated against histology in humans. The aims of this study were to identify a cut-off T2 for prediction of myocardial oedema following acute reperfused myocardial infarction and determine if infarct characteristics affect T2 values. In addition, this study aims to determine if T2 values are associated with the ECV following STEMI. Methods 50 consecutive patients presenting with STEMI to the Bristol Heart Institute Primary PCI service were approached for inclusion in the study. Patients had a CMR scan day 2 following STEMI. T2 values were assessed by T2 mapping. The myocardium was divided according to the AHA segments. Regional wall motion, LGE transmurality, presence of persistent microvascular obstruction (PMVO) and T2 values were assessed per segment. Segments were deemed affected if they did not have normal wall motion. In addition, a further 30 patients had a CMR day 2 following STEMI. Pre-contrast T1, T2 valves were assessed. Post contrast T1 was measured at 25 minutes following contrast administration. ECV was calculated as:

Localised inhibition of microrna-15 and -16 results in an improved angiogenic recovery following limb ischaemia

s / International Journal of Surgery 12 (2014) S13eS117 S15 assessors (1 surgery, 1 pathology). Survival was analyzed using KaplaneMeier curves and the Log-rank test. Results: There is increased tumour epithelial cytoplasmic staining for NR4A2, and an altered nuclear-cytoplasmic ratio with more cytoplasmic NR4A2 in tumour compared to matched normal tissue (p 1⁄4 0.001). High tumour cytoplasmic NR4A2 is associated with a significantly worse overall and disease specific survival in colorectal cancer. (5-year DSS 64% high cytoplasmic NR4A2 versus 80% low cytoplasmic NR4A2, log-rank test p1⁄40.049, 5-year OS p1⁄40.003) Conclusions: There is marked cytoplasmic mislocalisation of NR4A2 in colon cancer. High tumour cytoplasmic NR4A2 is associated with an adverse prognosis. 0921: LOCALISED INHIBITION OF MICRORNA-15 AND -16 RESULTS IN AN IMPROVED ANGIOGENIC RECOVERY FOLLOWING LIMB ISCHAEMIA Saran Shantikumar, Lynsey Howard, Micol Marchetti, Marco Meloni, Costanza Emanueli. Bristol Heart Institute, Bristol, UK. Introduction: MicroRNAs (miRNA;miR) are small non-coding RNAswhich negatively regulatemRNA translation. miR-15m Department of Pathology, Cambridge University,

The effects of propofol cardioplegia on blood and myocardial biomarkers of stress and injury in patients with isolated coronary artery bypass grafting or aortic valve replacement using cardiopulmonary bypass: protocol for a single-center randomized controlled trial.

BackgroundDespite improved myocardial protection strategies, cardioplegic arrest and ischemia still result in reperfusion injury. We have previously published a study describing the effects of propofol (an anesthetic agent commonly used in cardiac surgery) on metabolic stress, cardiac function, and injury in a clinically relevant animal model. We concluded that cardioplegia supplementation with propofol at a concentration relevant to the human clinical setting resulted in improved hemodynamic function, reduced oxidative stress, and reduced reperfusion injury when compared to standard cardioplegia.ObjectiveThe Propofol cardioplegia for Myocardial Protection Trial (ProMPT) aims to translate the successful animal intervention to the human clinical setting. We aim to test the hypothesis that supplementation of the cardioplegic solution with propofol will be cardioprotective for patients undergoing isolated coronary artery bypass graft or aortic valve replacement surgery with cardiopulmonary bypass.MethodsThe trial is a single-center, placebo-controlled, randomized trial with blinding of participants, health care staff, and the research team. Patients aged between 18 and 80 years undergoing nonemergency isolated coronary artery bypass graft or aortic valve replacement surgery with cardiopulmonary bypass at the Bristol Heart Institute are being invited to participate. Participants are randomly assigned in a 1:1 ratio to either cardioplegia supplementation with propofol (intervention) or cardioplegia supplementation with intralipid (placebo) using a secure, concealed, Internet-based randomization system. Randomization is stratified by operation type and minimized by diabetes mellitus status. Biomarkers of cardiac injury and metabolism are being assessed to investigate any cardioprotection conferred. The primary outcome is myocardial injury, studied by measuring myocardial troponin T. The trial is designed to test hypotheses about the superiority of the intervention within each surgical stratum. The sample size of 96 participants has been chosen to achieve 80% power to detect standardized differences of 0.5 at a significance level of 5% (2-tailed) assuming equal numbers in each surgical stratum.ResultsA total of 96 patients have been successfully recruited over a 2-year period. Results are to be published in late 2014.ConclusionsDesigning a practicable method for delivering a potentially protective dose of propofol to the heart during cardiac surgery was challenging. If our approach confirms the potential of propofol to reduce damage during cardiac surgery, we plan to design a larger multicenter trial to detect differences in clinical outcomes.Trial RegistrationInternational Standard Randomized Controlled Trial Number (ISRCTN): 84968882; http://www.controlled-trials.com/ISRCTN84968882/ProMPT (Archived by WebCite at http://www.webcitation.org/6Qi8A51BS).

99 5 Year Experience of Tavi Implantation: Patient Characteristics, Morbidity and Mortality

AimsTo define the characteristics of a real world population treated with transcatheter aortic valve implantation (TAVI) in a tertiary hospital and to evaluateclinical outcome. This includes in hospital morbidity rates...

Database development to maximise recruitment in a busy cardiac surgery department

The Bristol Clinical Trials and Evaluation Unit run multiple cardiac surgery trials in the Bristol Heart Institute (BHI), where approximately 1600 cardiac surgery operations take place annually. We will describe the operational challenges of managing the recruiting process across a range of studies and the database management solution we have developed to help us maximise recruitment.

Perioperative compliance with VSGBI quality improvement framework for major limb amputations in a single vascular centre

Perioperative compliance with VSGBI quality improvement framework for major limb amputations in a single vascular centre

Transcatheter and endovascular stent graft management of coarctation-related pseudoaneurysms

ObjectiveSurgical correction of congenital aortic coarctation can lead to a number of important problems including late pseudoaneurysm formation. Redo surgery has a significant risk. Endovascular stent graft repair is increasingly...