Surgical Techniques and Outcomes in Patients With Intra-Cardiac Abscesses Complicating Infective Endocarditis.

Background: An intra-cardiac abscess is a serious complication of both native (NV-IE) and prosthetic valve infective endocarditis (PV-IE). Despite being an accepted indication for surgery, controversies remain regarding the optimal timing and type of operation. We aimed to report the outcomes of patients managed for intra-cardiac abscesses over more than a decade. Methods: Patients aged ≥18 years managed for intra-cardiac abscess between 1 January 2005 and 31 December 2017 were identified from a prospectively collected IE database. The primary outcome was 30-day mortality in operated patients and secondary outcomes were freedom from re-infection, re-operation and long-term mortality comparing those patients with aortic root abscess who underwent aortic valve replacement (AVR) and those who received aortic root replacement (ARR). Results: Fifty-nine patients developed an intra-cardiac abscess, and their median age was 55 (43-71) years; among them, 44 (75%) were men, and 10 (17%) were persons who injected drugs. Infection with beta-haemolytic streptococci was associated with NV-IE (p = 0.009) and coagulase-negative staphylococci with PV-IE (p = 0.005). Forty-four (75%) underwent an operation, and among those with aortic root abscess, 27 underwent AVR and 12 ARR. Thirty-day mortality was associated with infection with S. aureus (p = 0.006) but not the type or timing of the operation. Survival in operated patients was 66% at 1 year and 59% at 5 years. In operated patients, none had a relapse, although six developed late recurrence. Freedom from infection, re-operation and long-term mortality were similar in patients undergoing AVR compared to ARR. Conclusion: Patients diagnosed with intra-cardiac abscess who were not operated on had very poor survival. In those who underwent an operation, either by AVR or ARR based upon patient factors, imaging and intra-operative findings outcomes were similar.

Prosthetic valve endocarditis following transcatheter aortic valve implantation.

AIMS: The aims were to report the incidence and outcomes of transcatheter aortic valve implantation-infective endocarditis (TAVI-IE) from a high-volume TAVI centre in the United Kingdom, including how incidence varies relative to time from the procedure, and to assess the performance of modified Duke criteria in the diagnosis of TAVI-IE. METHODS: The retrospective, cohort study included all patients who underwent TAVI at Leeds Teaching Hospitals Trust during a 10-year period. Outcome measures were the incidence of TAVI-IE, the accuracy of the modified Duke criteria and the mortality rate. RESULTS: A total of 1337 patients were followed up for a median of 2.3 years. Thirteen patients (0.97%) were diagnosed with TAVI-IE, mean age of 81.3 years (SD 5.1 years). Four patients (30.8%) fulfilled modified Duke criteria for definite infective endocarditis. The remaining nine patients (69.2%) fulfilled the modified Duke criteria for possible infective endocarditis. In the majority (7/13; 53.8%) the causative organism was streptococcal. Cumulative incidence of TAVI-IE has risen in line with the number of patients living with TAVI prostheses, and cumulative number of TAVI-years. However, in relation to the number of 100 TAVI-years, the infection rate has remained low and static over the last 6 years. The in-hospital mortality rate was 38.5%, all attributable to TAVI-IE. CONCLUSION: The incidence of TAVI-IE was 0.97%, with an associated all-cause mortality of 53.8%. The incidence relative to the number of TAVI-years has remained low and static in recent years. The modified Duke criteria have relatively low sensitivity in the diagnosis of TAVI-IE, meaning that a high index of suspicion is required.

Long-term Outcomes Are Poor in Intravenous Drug Users Following Infective Endocarditis, Even After Surgery.

BACKGROUND: Previous studies of outcomes in people who inject drugs (PWID) with infective endocarditis (IE) have often been retrospective, have had small sample sizes, and the duration of follow-up has been short and limited to patients who were operated on. METHODS: PWID treated for IE between 1 January 2006 and 31 December 2016 were identified from a prospectively collected database. PWID hospitalized with other infections acted as a novel comparison group. Outcomes were all-cause mortality, cause of death, relapse, recurrence, and reoperation. RESULTS: There were 105 episodes of IE in 92 PWID and 112 episodes of other infections in 107 PWID in whom IE was suspected but rejected. Survival at 30 days for the IE group was 85%, and 30-day survival following surgery was 96%. The most common pathogens were Staphylococcus species (60%) and Streptococcus species (30%). The surgical intervention rate was 47%. Survival for the IE group at 1, 3, 5, and 10 years was 74%, 63%, 58%, and 44%, respectively. This was significantly lower compared with the comparator group of other infections in PWID (P = .0002). Mortality was higher in patients who required surgery compared with those who did not (hazard ratio, 1.8 [95% confidence interval, .95-3.3]). The commonest cause of death was infection (66%), usually a further episode of IE (55%). CONCLUSIONS: Although early survival was good, long-term life expectancy was low. This was attributable to ongoing infection risk, rather than other factors known to affect prognosis in PWID. Surgery conferred no long-term survival advantage. More efforts are needed to reduce reinfection risk following an episode of IE in PWID.While early survival for people who inject drugs (PWID) with infective endocarditis is good, long-term survival is poor due to ongoing infection risk. Surgery conferred no long-term survival advantage, so more efforts are needed to reduce reinfection risks for PWID.

'Caveat emptor': the cautionary tale of endocarditis and the potential pitfalls of clinical coding data-an electronic health records study.

BACKGROUND: Diagnostic codes from electronic health records are widely used to assess patterns of disease. Infective endocarditis is an uncommon but serious infection, with objective diagnostic criteria. Electronic health records have been used to explore the impact of changing guidance on antibiotic prophylaxis for dental procedures on incidence, but limited data on the accuracy of the diagnostic codes exists. Endocarditis was used as a clinically relevant case study to investigate the relationship between clinical cases and diagnostic codes, to understand discrepancies and to improve design of future studies. METHODS: Electronic health record data from two UK tertiary care centres were linked with data from a prospectively collected clinical endocarditis service database (Leeds Teaching Hospital) or retrospective clinical audit and microbiology laboratory blood culture results (Oxford University Hospitals Trust). The relationship between diagnostic codes for endocarditis and confirmed clinical cases according to the objective Duke criteria was assessed, and impact on estimations of disease incidence and trends. RESULTS: In Leeds 2006-2016, 738/1681(44%) admissions containing any endocarditis code represented a definite/possible case, whilst 263/1001(24%) definite/possible endocarditis cases had no endocarditis code assigned. In Oxford 2010-2016, 307/552(56%) reviewed endocarditis-coded admissions represented a clinical case. Diagnostic codes used by most endocarditis studies had good positive predictive value (PPV) but low sensitivity (e.g. I33-primary 82% and 43% respectively); one (I38-secondary) had PPV under 6%. Estimating endocarditis incidence using raw admission data overestimated incidence trends twofold. Removing records with non-specific codes, very short stays and readmissions improved predictive ability. Estimating incidence of streptococcal endocarditis using secondary codes also overestimated increases in incidence over time. Reasons for discrepancies included changes in coding behaviour over time, and coding guidance allowing assignment of a code mentioning 'endocarditis' where endocarditis was never mentioned in the clinical notes. CONCLUSIONS: Commonly used diagnostic codes in studies of endocarditis had good predictive ability. Other apparently plausible codes were poorly predictive. Use of diagnostic codes without examining sensitivity and predictive ability can give inaccurate estimations of incidence and trends. Similar considerations may apply to other diseases. Health record studies require validation of diagnostic codes and careful data curation to minimise risk of serious errors.

Optimising pacemaker therapy and medical therapy in pacemaker patients for heart failure: protocol for the OPT-PACE randomised controlled trial.

INTRODUCTION: Permanent artificial pacemaker implantation is a safe and effective treatment for bradycardia and is associated with extended longevity and improved quality of life. However, the most common long-term complication of standard pacemaker therapy is pacemaker-associated heart failure. Pacemaker follow-up is potentially an opportunity to screen for heart failure to assess and optimise patient devices and medical therapy. METHODS AND ANALYSIS: The study is a multicentre, phase-3 randomised trial. The 1200 participants will be people who have a permanent pacemaker for bradycardia for at least 12 months, randomly assigned to undergo a transthoracic echocardiogram with their pacemaker check, thereby tailoring their management directed by left ventricular function or the pacemaker check alone, continuing with routine follow-up. The primary outcome measure is time to all-cause mortality or heart failure hospitalisation. Secondary outcomes include external validation of our risk stratification model to predict onset of heart failure and quality of life assessment. ETHICS AND DISSEMINATION: The trial design and protocol have received national ethical approval (12/YH/0487). The results of this randomised trial will be published in international peer-reviewed journals, communicated to healthcare professionals and patient involvement groups and highlighted using social media campaigns. TRIAL REGISTRATION NUMBER: NCT01819662.

Multicentre randomised trial comparing contact force with electrical coupling index in atrial flutter ablation (VERISMART trial).

INTRODUCTION: Electrical coupling index (ECI) and contact force (CF) have been developed to aid lesion formation during catheter ablation. ECI measures tissue impedance and capacitance whilst CF measures direct contact. The aim was to determine whether the presence of catheter / tissue interaction information, such as ECI and CF, reduce time to achieve bidirectional cavotricuspid isthmus block during atrial flutter (AFL) ablation. METHODS: Patients with paroxysmal or persistent AFL were randomised to CF visible (range 5-40g), CF not visible, ECI visible (change of 12%) or ECI not visible. Follow-up occurred at 3 and 6 months and included a 7 day ECG recording. The primary endpoint was time to bidirectional cavotricuspid isthmus block. RESULTS: 114 patients were randomised, 16 were excluded. Time to bidirectional block was significantly shorter when ECI was visible (median 30.0 mins (IQR 31) to median 10.5mins (IQR 12) p 0.023) versus ECI not visible. There was a trend towards a shorter time to bidirectional block when CF was visible. Higher force was applied when CF was visible (median 9.03g (IQR 7.4) vs. 11.3g (5.5) p 0.017). There was no difference in the acute recurrence of conduction between groups. The complication rate was 2%, AFL recurrence was 1.1% and at 6 month follow-up, 12% had atrial fibrillation. CONCLUSION: The use of tissue contact information during AFL ablation was associated with reduced time taken to achieve bidirectional block when ECI was visible. Contact force data improved contact when visible with a trend towards a reduction in the procedural endpoint. ClinicalTrials.gov trial identifier: NCT02490033.

Impact of the duration of antibiotic therapy on relapse and survival following surgery for active infective endocarditis.

OBJECTIVES: Surgery is often required for acute infective endocarditis (IE) to repair or replace damaged heart valves. Traditionally, long courses of antibiotic treatment have been prescribed after surgery for active IE for fear of infecting newly implanted/repaired valves, but the need for this, in the present era of enhanced antimicrobial stewardship, has been questioned. In our institution, the choice and duration of antimicrobial therapy is tailored to individual patients by a multidisciplinary team with an interest in IE. The influence of the duration of postoperative antibiotic therapy on outcomes was studied in patients requiring surgery prior to the completion of a planned course of antibiotic therapy. METHODS: This was a retrospective observational study on patients with acute IE requiring surgery between January 2004 and December 2015. The primary outcome was relapse. Secondary outcomes were early reoperation and 1-year mortality. RESULTS: In total, 182 IE episodes were included in the final analysis. The median duration of postoperative antibiotic therapy was 23.5 days (interquartile range 12-40 days) and decreased significantly during the period of study (P < 0.001). There were 2 relapses (1.1%) and 18 (9.9%) postoperative deaths within 1 year. Nine (5%) patients underwent early reoperation. The duration of postoperative antibiotic therapy did not affect either the primary or the secondary outcomes. CONCLUSIONS: This work supports previous findings that selected patients who require surgery during active IE can be safely given shorter courses of postoperative antibiotics without an impact on relapse of infection or survival.

A novel diagnostic aid for intra-abdominal adhesion detection in cine-MRI: pilot study and initial diagnostic impressions.

OBJECTIVE: A non-invasive diagnostic technique for abdominal adhesions is not currently available. Capture of abdominal motion due to respiration in cine-MRI has shown promise, but is difficult to interpret. This article explores the value of a complimentary diagnostic aid to facilitate the non-invasive detection of abdominal adhesions using cine-MRI. METHOD: An image processing technique was developed to quantify the amount of sliding that occurs between the organs of the abdomen and the abdominal wall in sagittal cine-MRI slices. The technique produces a "sheargram" which depicts the amount of sliding which has occurred over 1-3 respiratory cycles. A retrospective cohort of 52 patients, scanned for suspected adhesions, made 281 cine-MRI sagittal slices available for processing. The resulting sheargrams were reported by two operators and compared with expert clinical judgment of the cine-MRI scans. RESULTS: The sheargram matched clinical judgment in 84% of all sagittal slices and 93-96% of positive adhesions were identified on the sheargram. The sheargram displayed a slight skew towards sensitivity over specificity, with a high positive adhesion detection rate but at the expense of false positives. CONCLUSION: Good correlation between sheargram and absence/presence of inferred adhesions indicates quantification of sliding motion has potential to aid adhesion detection in cine-MRI. ADVANCES IN KNOWLEDGE: This is the first attempt to clinically evaluate a novel image processing technique quantifying the sliding motion of the abdominal contents against the abdominal wall. The results of this pilot study reveal its potential as a diagnostic aid for detection of abdominal adhesions.

South Asian ethnicity is associated with a lower prevalence of atrial fibrillation despite greater prevalence of established risk factors: a population-based study in Bradford Metropolitan District.

AIMS: Previous studies indicate that South Asians (SAs) may have a reduced risk of developing atrial fibrillation (AF) despite having a higher prevalence of traditional cardiovascular risk factors. This observational study was designed to explore the relative differences between SAs and Whites in a well-defined, multi-ethnic population with careful consideration of traditional cardiovascular risk factors that are thought to contribute to the development of AF. METHODS AND RESULTS: Anonymized data from 417 575 adults were sourced from primary care records within Bradford Metropolitan District, UK. Atrial fibrillation diagnosis was indicated by the presence on the AF Quality Outcomes Framework register. Self-reported ethnicity was mapped to census ethnic codes. The age-standardized prevalence rates of AF were calculated for comparison between the White and SA populations; our study sample presented relative proportions of 2.39 and 0.4%. Multivariable logistic regression analysis was performed to estimate the odds of developing AF given SA ethnicity. Adjustment for age, sex, and established risk factors found a 71% reduction in odds of AF in SAs when compared with Whites [odds ratio (OR): 0.29, 95% confidence interval (CI): 0.26-0.32]. When stratified by ethnicity, analyses revealed significantly different odds of AF for patients with diabetes; diabetes was not associated with the development of AF in the SA population (0.81, 95% CI: 0.63-1.05). CONCLUSION: This study, in a multi-ethnic population, presents ethnicity as a predictor of AF in which prevalence is significantly lower in SAs when compared with Whites. This is despite SAs having a higher frequency of established risk factors for the development of AF, such as ischaemic heart disease, heart failure, hypertension, and type 2 diabetes. These findings are consistent with previous literature and add weight to the need for further investigation, although this is the first study to investigate the differential associations of individual risk factors with development of AF.

Effects of Vitamin D on Cardiac Function in Patients With Chronic HF: The VINDICATE Study.

BACKGROUND: Patients with chronic heart failure (HF) secondary to left ventricular systolic dysfunction (LVSD) are frequently deficient in vitamin D. Low vitamin D levels are associated with a worse prognosis. OBJECTIVES: The VINDICATE (VitamIN D treatIng patients with Chronic heArT failurE) study was undertaken to establish safety and efficacy of high-dose 25 (OH) vitamin D3 (cholecalciferol) supplementation in patients with chronic HF due to LVSD. METHODS: We enrolled 229 patients (179 men) with chronic HF due to LVSD and vitamin D deficiency (cholecalciferol <50 nmol/l [<20 ng/ml]). Participants were allocated to 1 year of vitamin D3 supplementation (4,000 IU [100 µg] daily) or matching non-calcium-based placebo. The primary endpoint was change in 6-minute walk distance between baseline and 12 months. Secondary endpoints included change in LV ejection fraction at 1 year, and safety measures of renal function and serum calcium concentration assessed every 3 months. RESULTS: One year of high-dose vitamin D3 supplementation did not improve 6-min walk distance at 1 year, but was associated with a significant improvement in cardiac function (LV ejection fraction +6.07% [95% confidence interval (CI): 3.20 to 8.95; p < 0.0001]); and a reversal of LV remodeling (LV end diastolic diameter -2.49 mm [95% CI: -4.09 to -0.90; p = 0.002] and LV end systolic diameter -2.09 mm [95% CI: -4.11 to -0.06 p = 0.043]). CONCLUSIONS: One year of 100 µg daily vitamin D3 supplementation does not improve 6-min walk distance but has beneficial effects on LV structure and function in patients on contemporary optimal medical therapy. Further studies are necessary to determine whether these translate to improvements in outcomes. (VitamIN D Treating patIents With Chronic heArT failurE [VINDICATE]; NCT01619891).

A Novel Diagnostic Aid for Detection of Intra-Abdominal Adhesions to the Anterior Abdominal Wall Using Dynamic Magnetic Resonance Imaging.

Introduction. Abdominal adhesions can cause serious morbidity and complicate subsequent operations. Their diagnosis is often one of exclusion due to a lack of a reliable, non-invasive diagnostic technique. Development and testing of a candidate technique are described below. Method. During respiration, smooth visceral sliding motion occurs between the abdominal contents and the walls of the abdominal cavity. We describe a technique involving image segmentation and registration to calculate shear as an analogue for visceral slide based on the tracking of structures throughout the respiratory cycle. The presence of an adhesion is attributed to a resistance to visceral slide resulting in a discernible reduction in shear. The abdominal movement due to respiration is captured in sagittal dynamic MR images. Results. Clinical images were selected for analysis, including a patient with a surgically confirmed adhesion. Discernible reduction in shear was observed at the location of the adhesion while a consistent, gradually changing shear was observed in the healthy volunteers. Conclusion. The technique and its validation show encouraging results for adhesion detection but a larger study is now required to confirm its potential.

An evaluation of 20 year survival in patients with diabetes mellitus and acute myocardial infarction.

BACKGROUND: Diabetes mellitus (DM) is an established adverse prognostic factor in patients sustaining myocardial infarction (MI). However, its impact on long-term survival remains less clear. The aim of this observational study was to quantify lifetime mortality and years of life lost after MI in patients with and without DM. METHODS: In 1995, 2153 individuals with MI were recruited from 20 adjacent hospitals within Yorkshire, UK. Median survival, all-cause mortality at 20 years and lost years of life when compared to actuarial predictions were compared in patients with and without DM. Landmark analyses were conducted to define the ongoing impact of DM beyond specified time points. RESULTS: 13% (279/2153) had known DM. They experienced higher mortality at 30 days (33.1% vs 24.6%; p<0.0001) and at 20 years (84.9% vs 75.7%; p<0.0001). Overall, there was a 48% increased risk of death (p<0.0001), which persisted after adjustment for potential confounders. There was no interaction between DM and prior MI in predicting mortality (p=0.67). Median survival decreased by 3.3 years (p<0.0001). The adverse impact of DM persisted in sequential landmark analyses at 1, 5 and 10 years. Presence of DM conferred 2 extra years of life lost when compared with actuarial predictions (8 vs 6 years; p<0.0001). CONCLUSIONS: DM remains an independent adverse prognostic factor in the long-term after MI. Persistently diverging survival curves support enduring efforts to reduce mortality late after MI.

Towards radiological diagnosis of abdominal adhesions based on motion signatures derived from sequences of cine-MRI images.

This paper reports novel development and preliminary application of an image registration technique for diagnosis of abdominal adhesions imaged with cine-MRI (cMRI). Adhesions can severely compromise the movement and physiological function of the abdominal contents, and their presence is difficult to detect. The image registration approach presented here is designed to expose anomalies in movement of the abdominal organs, providing a movement signature that is indicative of underlying structural abnormalities. Validation of the technique was performed using structurally based in vitro and in silico models, supported with Receiver Operating Characteristic (ROC) methods. For the more challenging cases presented to the small cohort of 4 observers, the AUC (area under curve) improved from a mean value of 0.67 ± 0.02 (without image registration assistance) to a value of 0.87 ± 0.02 when image registration support was included. Also, in these cases, a reduction in time to diagnosis was observed, decreasing by between 20% and 50%. These results provided sufficient confidence to apply the image registration diagnostic protocol to sample magnetic resonance imaging data from healthy volunteers as well as a patient suffering from encapsulating peritoneal sclerosis (an extreme form of adhesions) where immobilization of the gut by cocooning of the small bowel is observed. The results as a whole support the hypothesis that movement analysis using image registration offers a possible method for detecting underlying structural anomalies and encourages further investigation.

Initial observations using a novel "cine" magnetic resonance imaging technique to detect changes in abdominal motion caused by encapsulating peritoneal sclerosis.

Encapsulating peritoneal sclerosis (EPS) is an uncommon complication of peritoneal dialysis (PD), with high mortality and morbidity. The peritoneum thickens, dysfunctions, and forms a cocoon that progressively "strangulates" the small intestine, causing malnutrition, ischemia, and infarction. There is as yet no reliable noninvasive means of diagnosis, but recent developments in image analysis of cine magnetic resonance imaging for the recognition of adhesions offers a way forward. We used this protocol before surgery in 3 patients with suspected EPS. Image analysis revealed patterns of abdominal movement that were markedly different from the patterns in healthy volunteers. The volunteers showed marked movement throughout the abdomen; in contrast, movement in EPS patients was restricted to just below the diaphragm. This clear difference provides early "proof of principle" of the approach that we have developed.

A framework for the modeling of gut blood flow regulation and postprandial hyperaemia.

After a meal the activity of the gut increases markedly as digestion takes place. Associated with this increase in activity is an increase in blood flow, which has been shown to be dependent on factors such as caloric content and constitution of the meal. Much qualitative work has been carried out regarding mechanisms for the presence of food in a section of gut producing increased blood flow to that section, but there are still many aspects of this process that are not fully understood. In this paper we briefly review current knowledge on several relevant areas relating to gut blood flow, focusing on quantitative data where available and highlighting areas where further research is needed. We then present new data on the effect of feeding on flow in the superior mesenteric artery. Finally, we describe a framework for combining this data to produce a single model describing the mechanisms involved in postprandial hyperaemia. For a section of the model, where appropriate data are available, preliminary results are presented.