Artificial intelligence, big data and heart transplantation: Actualities

BACKGROUND

As diagnostic and prognostic models developed by traditional statistics perform poorly in real-world, artificial intelligence (AI) and Big Data (BD) may improve the supply chain of heart transplantation (HTx), allocation opportunities, correct treatments, and finally optimize HTx outcome. We explored available studies, and discussed opportunities and limits of medical application of AI to the field of HTx.

METHOD

A systematic overview of studies published up to December 31st, 2022, in English on peer-revied journals, have been identified through PUBMED-MEDLINE-WEB of Science, referring to HTx, AI, BD. Studies were grouped in 4 domains based on main studies' objectives and results: etiology, diagnosis, prognosis, treatment. A systematic attempt was made to evaluate studies by the Prediction model Risk Of Bias ASsessment Tool (PROBAST) and the Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis (TRIPOD).

RESULTS

Among the 27 publications selected, none used AI applied to BD. Of the selected studies, 4 fell in the domain of etiology, 6 in the domain of diagnosis, 3 in the domain of treatment, and 17 in that of prognosis, as AI was most frequently used for algorithmic prediction and discrimination of survival, but in retrospective cohorts and registries. AI-based algorithms appeared superior to probabilistic functions to predict patterns, but external validation was rarely employed. Indeed, based on PROBAST, selected studies showed, to some extent, significant risk of bias (especially in the domain of predictors and analysis). In addition, as example of applicability in the real-world, a free-use prediction algorithm developed through AI failed to predict 1-year mortality post-HTx in cases from our center.

CONCLUSIONS

While AI-based prognostic and diagnostic functions performed better than those developed by traditional statistics, risk of bias, lack of external validation, and relatively poor applicability, may affect AI-based tools. More unbiased research with high quality BD meant for AI, transparency and external validations, are needed to have medical AI as a systematic aid to clinical decision making in HTx.

Big Data in cardiac surgery: real world and perspectives

Big Data, and the derived analysis techniques, such as artificial intelligence and machine learning, have been considered a revolution in the modern practice of medicine. Big Data comes from multiple sources, encompassing electronic health records, clinical studies, imaging data, registries, administrative databases, patient-reported outcomes and OMICS profiles. The main objective of such analyses is to unveil hidden associations and patterns. In cardiac surgery, the main targets for the use of Big Data are the construction of predictive models to recognize patterns or associations better representing the individual risk or prognosis compared to classical surgical risk scores. The results of these studies contributed to kindle the interest for personalized medicine and contributed to recognize the limitations of randomized controlled trials in representing the real world. However, the main sources of evidence for guidelines and recommendations remain RCTs and meta-analysis. The extent of the revolution of Big Data and new analytical models in cardiac surgery is yet to be determined.

Diagnostic value of electroanatomical mapping in patients with suspected arrhythmogenic cardiomyopathy

Background

Case series suggested that low voltage areas (LVA) on invasive electroanatomical mapping (EAM) could identify arrhythmogenic cardiomyopathy (ACM) at an earlier stage as compared to late gadolinium enhancement (LGE) and fatty infiltration on cardiac magnetic resonance (CMR). Data comparing LVA with structural abnormalities on CMR are lacking.

Purpose

To report the prevalence of substrate abnormalities identified by EAM vs. CMR in a cohort of patients with suspected ACM.

Methods

We retrospectively identified 66 consecutive patients with suspected ACM, who underwent EAM following clinical onset with ventricular arrhythmias. The cutoff value for EAM-defined LVA was <0.5 mV bipolar, <8 mV unipolar. Data from a prior CMR, performed no more than 12 months before, were used for comparison.

Results

The study cohort (mean age 47 years, range 21–76; 83% males; mean left ventricular ejection fraction 53%, range 28–70%) was composed of patients with suspected ACM involving either the right (n=62) or the left ventricle (n=4) following presentation with sustained monomorphic ventricular tachycardia. EAM was obtained by isolated endocardial, epicardial, or combined approach, respectively, in 11 (17%), 15 (23%) and 40 (61%) patients. Overall, 61 patients (92%) had documented LVA, of whom 89% showed an epicardial localization. In the same population, CMR identified a lower prevalence of substrate abnormalities (LGE 65%; fatty infiltration 50%). In particular, there were 27 patients (41%) with EAM-defined LVA and absent substrate abnormalities on CMR. Based on the 2010 Task Force Criteria and the 2021 Padua Criteria, a definite diagnosis of ACM was missing for a total of 19 patients (29%): due to the uniform identification of LVA in the absence of CMR abnormalities, EAM helped to establish the most likely diagnosis of ACM in all of them (19/19).

Conclusions

Our data suggest that EAM is capable of identifying substrate abnormalities in a consistent proportion of patients with suspected ACM and absent abnormalities on CMR. In this setting, the implementation of LVA to the current diagnostic criteria could improve the diagnostic yield for ACM.

Funding Acknowledgement

Type of funding sources: None.

High prevalence of malignant ventricular arrhythmias in patients with early-stage left ventricular noncompaction

Background

Early-stage left ventricular non compaction (LVNC) is a nonischemic cardiomyopathy characterized with nondilated phenotype and unpredictable risk of malignant ventricular arrhythmias (MVA).

Purpose

To report the occurrence of MVA in patients with early-stage LVNC.

Methods

Consecutive patients (n=63) diagnosed with LVNC according to recognized criteria either on transthoracic echocardiogram or cardiac magnetic resonance were retrospectively enrolled. Patients with late-stage LVNC, defined by a coexistent dilated cardiomyopathy phenotype, were excluded (n=49). Patient-tailored medical treatment, as well as ICD implantation strategies, were based on the updated ESC guidelines integrated by the experience of a referral center for arrhythmia management. The study endpoint was the occurrence of MVA (defined as sustained VT, VF, or appropriate ICD therapy) by 5-year follow-up.

Results

The study cohort consisted of 14 patients (mean age 37±17 y, 64% males), presenting with palpitation (n=4), syncope (n=4), or dyspnea on effort (n=6). LVNC was diagnosed by echocardiogram and cardiac magnetic resonance in 13 and 1 patients, respectively. Because of nonmalignant VA, seven patients (50%) underwent ICD implant before discharge. By 5-year follow-up, 5 patients (36%) experienced MVA, including VF or appropriate ICD shocks for fast VT. Left ventricular ejection fraction (LVEF) ≥45% was the only factor associated with the occurrence of MVA (5/11 event in cases with LVEF ≥45% vs. 0/3 events in controls with LVEF <45%; p=0.145). Baseline features, including age, gender, NC/C ratio, and clinical presentation were comparable between cases with LVEF ≥45% and controls, all p>0.05. Drug treatment, including RAAS inhibitors, betablockers and antiarrhythmics was also comparable.

Conclusions

Our preliminary data show that in early-stage LVNC the occurrence of MVA is higher for patients with LVEF ≥45%. Efforts are needed to identify earlier predictors of arrhythmic risk, to improve patient selection for ICD implant.

Funding Acknowledgement

Type of funding sources: None.

PTX3 as a novel inflammatory biomarker in patients with myocarditis

Background

Pentraxin-3 (PTX3) is an acute phase protein, which plays pivotal roles in innate immunity and inflammation. Among cardiovascular diseases, PTX3 was found to be elevated in acute myocardial infarction, chronic heart failure, and cardiac arrest. So far, however, PTX3 has never been investigated in the context of myocarditis.

Purpose

To evaluate PTX3 as a circulating marker of inflammation in patients with suspected myocarditis.

Methods

We enrolled 30 consecutive inpatients with new diagnosis of myocarditis, proven both by the updated Lake Louise criteria on cardiac magnetic resonance (CMR), and by the Dallas criteria on endomyocardial biopsy (EMB) (100%). Circulating serum PTX3 was assessed at the time of EMB, by ELISA technique using a commercial kit. Normal values for PTX3 were considered as <2 ng/mL, as in previous studies. A normal control group (n=10) was used for results validation of PTX3.

Results

In our cohort (77% males, age 50±18 y; median left ventricle ejection fraction [LVEF] 50%, IQR 30–59%), PTX3 levels were assessed in 30 patients. PTX3 levels were elevated in 26/30 (87%) patients with myocarditis (median 4,36 ng/mL, IQR 2,44–6,72, range 1,20–40,0), and in none (0/10) among healthy controls (median 1,28 ng/mL, IQR 1,04–1,36, range 0,77–1,94) (p=0,001). In the study group, the yield of other cardiac biomarkers was lower: 12/30 (40%) for C-reactive protein, 23/30 (77%) for T-troponin, and 20/30 (67%) for NTproBNP. PTX3 was constantly elevated in patients presenting with heart failure (HF) (16/16, 100%), compared with those presenting with acute coronary syndrome-like (8/10, 80%), or arrhythmias (2/4, 50%) (p=0,024). In particular, elevated PTX3 was associated with systolic dysfunction (LVEF <50%) at discharge (16/16 vs. 10/14, p=0,022).

Conclusion

Our preliminary data suggest PTX3 as a novel biomarker with potential diagnostic and prognostic value for myocarditis and inflammatory cardiomyopathy.

Funding Acknowledgement

Type of funding sources: None.

Prognostic role of myocardial inflammation in patients with undefined left ventricular arrhythmogenic cardiomyopathy

Funding Acknowledgements

Type of funding sources: None.

Background

Etiology identification and risk stratification represent major issues for patients presenting with undefined left ventricular arrhythmogenic cardiomyopathy (ULVACM).

Purpose

To investigate the role of genetics and histology for ULVACM classification, management, and risk assessment.

Methods

We retrospectively analyzed a multicenter cohort of patients (screened n=1037) with ULVACM defined by ventricular arrhythmia (VA) onset, nonischemic late gadolinium enhancement (LGE) limited to the LV, and no severe dilated cardiomyopathy (LVEF≥40%). We selected patients undergoing both next generation sequencing (NGS) screening and endomyocardial biopsy (EMB) for etiology definition. When feasible, immunosuppressive therapy (IST) was used to target active myocardial inflammation (AMI). The study endpoint was a composite of cardiac death, heart transplantation and malignant VAs (VT, VF, appropriate ICD treatment).

Results

The study cohort is composed by 135 ULVACM patients (age 43±14 years, 63% males, LVEF 55±7 %). NGS identified pathogenic or likely-pathogenic variants (PVs/LPVs) consistent with ACM in 21 cases (16%), whereas EMB showed AMI in 78 patients (58%), including 13/21 PVs/LPVs+ (62%). After reclassification of 86 patients (64%), only 49 (36%) remained ULVACM. IST was started in 41/78 AMI patients (53%), including 9/13 PVs/LPVs+ (69%). Twenty patients (15%) met the study endpoint by 12 months, and 36 (27%) by the end of the study (60±27 months). Beyond malignant VT onset, AMI was the only predictor of events by 12 months (HR 5.0, 95%CI 1.4-18.1, p=0.007). No prognostic role was found for PVs/LPVs, except for the subgroup (n=77) with nonsustained VT onset. Among AMI patients, those treated by IST had a significantly lower occurrence of events, both by 12-months (1/41 vs. 16/37, p<0.001) and later (HR 0.05, 95%CI 0.01-0.21, p<0.001). Results were independently confirmed in PVs/LPVs+ and PVs/LPVs- cases. Excluding the IST population, the association of multiple factors among VT onset, PVs/LPVs, and AMI, resulted in an improved discrimination of arrhythmic risk profiles.

Conclusion

The combined genetic and histological workup allowed reclassification of up to 64% ULVACM patients, and substantially contributed into prognostic assessment. Furthermore, EMB identified suitable candidates for IST, who showed better outcomes irrespectively of their genotype.

C65 POST–DISCHARGE ARRHYTHMIC RISK STRATIFICATION OF PATIENTS WITH ACUTE MYOCARDITIS AND LIFE–THREATENING VENTRICULAR TACHYARRHYTHMIAS

Aims

The outcomes of patients presenting with acute myocarditis and life–threatening ventricular arrhythmias (LT–VA) are unclear. The aim of this study was to assess the incidence and predictors of recurrent major arrhythmic events (MAEs) after hospital discharge in this patient population.

Methods and Results

We retrospectively analysed 156 patients (median age 44 years; 77% male) discharged with a diagnosis of acute myocarditis and LT–VA from 16 hospitals worldwide. Diagnosis of myocarditis was based on histology or the combination of increased markers of cardiac injury and cardiac magnetic resonance (CMR) Lake Louise criteria. MAEs were defined as the relapse, after discharge, of sudden cardiac death or successfully defibrillated ventricular fibrillation, or sustained ventricular tachycardia (sVT) requiring implantable cardioverter–defibrillator therapy or synchronized external cardioversion. Median follow–up was 23months [first to third quartile (Q1–Q3) 7–60]. Fifty–eight (37.2%) patients experienced MAEs after discharge, at a median of 8 months (Q1–Q3 2.5–24.0 months; 60.3% of MAEs within the first year). At multivariable Cox analysis, variables independently associated with MAEs were presentation with sVT [hazard ratio (HR) 2.90, 95% confidence interval (CI) 1.38–6.11]; late gadolinium enhancement involving ≥2 myocardial segments (HR 4.51, 95% CI 2.39–8.53), and absence of positive short–tau inversion recovery (STIR) (HR 2.59, 95% CI 1.40–4.79) at first CMR.

Conclusions

In this international multicentre study, patients discharged free from HTx or LVAD after an acute myocarditis complicated by LT–VA had a recurrence of MAEs during follow–up of 37.2%, after a median time of 8 months. Initial CMR pattern and sVT at presentation stratify the risk of arrhythmia recurrence.

Comprehensive evaluation of Impella RP® in right ventricular failure

Right ventricular failure has a high morbidity and mortality in patients suffering from advanced heart failure, pulmonary hypertension, acute myocardial infarction after cardiac surgery and in left ventricular assist device patients. The Impella RP^® catheter is a mechanical circulatory device, positioned from a venous femoral percutaneous access and passing through the tricuspid and pulmonary valves, reaches the pulmonary artery. Impella RP (Abiomed Inc., MA, USA) acts as a direct right ventricle bypass and it provides a flow up to 4.4 liters per minute, unloading the right ventricle. The main contraindications are: thrombi in the vena cava, right atrium and ventricle and pulmonary artery; mechanical tricuspid or pulmonary prostheses. In this review, the principles of operations, clinical applications and results of Impella RP are summarized and evaluated.

Association between common cardiovascular risk factors and clinical phenotype in patients with hypertrophic cardiomyopathy from the European Society of Cardiology (ESC) EurObservational Research Programme (EORP) Cardiomyopathy/Myocarditis registry

AIMS

The interaction between common cardiovascular risk factors (CVRF) and hypertrophic cardiomyopathy (HCM) is poorly studied. We sought to explore the relation between CVRF and the clinical characteristics of patients with HCM enrolled in the EURObservational Research Programme (EORP) Cardiomyopathy registry.

METHODS AND RESULTS

1739 patients with HCM were studied. The relation between hypertension (HT), diabetes (DM), body mass index (BMI), and clinical traits was analysed. Analyses were stratified according to the presence or absence of a pathogenic variant in a sarcomere gene. The prevalence of HT, DM, and obesity (Ob) was 37, 10, and 21%, respectively. HT, DM, and Ob were associated with older age (P<0.001), less family history of HCM (HT and DM P<0.001), higher New York Heart Association (NYHA) class (P<0.001), atrial fibrillation (HT and DM P<0.001; Ob p = 0.03) and LV (left ventricular) diastolic dysfunction (HT and Ob P<0.001; DM P = 0.003). Stroke was more frequent in HT (P<0.001) and mutation-positive patients with DM (P = 0.02). HT and Ob were associated with higher provocable LV outflow tract gradients (HT P<0.001, Ob P = 0.036). LV hypertrophy was more severe in Ob (P = 0.018). HT and Ob were independently associated with NYHA class (OR 1.419, P = 0.017 and OR 1.584, P = 0.004, respectively). Other associations, including a higher proportion of females in HT and of systolic dysfunction in HT and Ob, were observed only in mutation-positive patients.

CONCLUSION

Common CVRF are associated with a more severe HCM phenotype, suggesting a proactive management of CVRF should be promoted. An interaction between genotype and CVRF was observed for some traits.

Eculizumab in patients with severe coronavirus disease 2019 (COVID-19) requiring continuous positive airway pressure ventilator support: Retrospective cohort study

Background

Complement activation contributes to lung dysfunction in coronavirus disease 2019 (COVID-19). We assessed whether C5 blockade with eculizumab could improve disease outcome.

Methods

In this single-centre, academic, unblinded study two 900 mg eculizumab doses were added-on standard therapy in ten COVID-19 patients admitted from February 2020 to April 2020 and receiving Continuous-Positive-Airway-Pressure (CPAP) ventilator support from ≤24 hours. We compared their outcomes with those of 65 contemporary similar controls. Primary outcome was respiratory rate at one week of ventilator support. Secondary outcomes included the combined endpoint of mortality and discharge with chronic complications.

Results

Baseline characteristics of eculizumab-treated patients and controls were similar. At baseline, sC5b-9 levels, ex vivo C5b-9 and thrombi deposition were increased. Ex vivo tests normalised in eculizumab-treated patients, but not in controls. In eculizumab-treated patients respiratory rate decreased from 26.8±7.3 breaths/min at baseline to 20.3±3.8 and 18.0±4.8 breaths/min at one and two weeks, respectively (p<0.05 for both), but did not change in controls. Between-group changes differed significantly at both time-points (p<0.01). Changes in respiratory rate correlated with concomitant changes in ex vivo C5b-9 deposits at one (rs = 0.706, p = 0.010) and two (rs = 0.751, p = 0.032) weeks. Over a median (IQR) period of 47.0 (14.0–121.0) days, four eculizumab-treated patients died or had chronic complications versus 52 controls [HR_Crude (95% CI): 0.26 (0.09–0.72), p = 0.010]. Between-group difference was significant even after adjustment for age, sex and baseline serum creatinine [HR_Adjusted (95% CI): 0.30 (0.10–0.84), p = 0.023]. Six patients and 13 controls were discharged without complications [HR_Crude (95% CI): 2.88 (1.08–7.70), p = 0.035]. Eculizumab was tolerated well. The main study limitations were the relatively small sample size and the non-randomised design.

Conclusions

In patients with severe COVID-19, eculizumab safely improved respiratory dysfunction and decreased the combined endpoint of mortality and discharge with chronic complications. Findings need confirmation in randomised controlled trials.

Clinical impact of continuous electrical monitoring in patients with arrhythmic myocarditis: a prospective cohort study

Background

Although potentially life-threatening, arrhythmias in myocarditis are under-reported.

Purpose

To assess diagnostic yield and clinical impact of continuous arrhythmia monitoring (CAM) in patients with arrhythmic myocarditis.

Methods

We enrolled consecutive adult patients (n=104; 71% males, age 47±11y, mean LVEF 50±13%) with biopsy-proven active myocarditis and de novo ventricular arrhythmias (VA). All patients underwent prospective monitoring by both sequential 24-hour Holter ECGs (4/y in the first year; 2/y in years 2–5; 1/y later) and CAM, including either ICD (n=62; 60%) or loop recorder (n=42; 40%).

Results

By 3.7±1.6 y follow-up, 45 patients (43%) had VT, 67 (64%) NSVT, and 102 (98%) premature ventricular complexes (PVC). As compared to Holter ECG (average 9.5 exams per patient), CAM identified more patients with VA (VT: 45 vs. 4; NSVT: 64 vs. 45; both p&lt;0.001), more VA episodes (VT: 100 vs. 4%; NSVT: 91 vs. 12%), and earlier NSVT timing (median 6 vs. 24 months, p&lt;0.001). Conversely, Holter ECG allowed VA morphology characterization and daily PVC quantification. The time to first treatment modification was 12±9 months by CAM vs. 33±16 months by Holter ECG (p&lt;0.001), and drug withdrawal was always CAM-dependent. Guided by CAM findings, 8 patients (8%) started anticoagulants for newly-diagnosed atrial arrhythmias. Differently from ICDs, loop recorders did not interfere with the interpretation of cardiac magnetic resonance.

Conclusion

In patients with arrhythmic myocarditis, CAM allowed accurate arrhythmia detection and showed a considerable clinical impact. As a complementary exam, VA characterization and PVC burden were better assed by repeated Holter ECGs.

Funding Acknowledgement

Type of funding sources: None.

Arrhythmic risk stratification in patients with clinically-suspected left ventricular arrhythmogenic cardiomyopathy

Background

Arrhythmic risk of patients with left ventricular arrhythmogenic cardiomyopathy (LVAC) is unpredictable.

Purpose

To identify risk facors associated with major ventricular tachyarrhythmias (VTA) in clinically-suspected LVAC patients.

Methods

We enrolled 127 consecutive patients (69% males, age 46±13 y, LVEF 54±7%) with clinically-suspected LVAC. All patients presented with either major (VT, VF) or minor VTA (NSVT, frequent VEB), and underwent extensive diagnostic workup to rule-out alternative diagnoses. Medical treatment and ICD implant were clinically-driven. Prospective follow-up was obtained via sequential 24h-Holter ECG (2–4/y) with or without continuous arrhythmia monitoring (ICD or implantable loop recorders, ILR). The primary endpoint was occurrence of major VTA (VT/VF/ICD therapy) by 24-month follow-up.

Results

At presentation, 56 (44%) and 71 patients (56%) had, respectively, major and minor VTA. Variants in desmosomal genes were identified in 7 of the 9 patients with clinically-indicated genetic test. Delayed gadolinium enhancement (DGE, average 23±12% of the LV mass) had anteroseptal distribution in 43 cases (34%). Monitoring strategy included ICD (n=64), ILR (n=33), or sequential Holer ECGs (n=30). By 24-month follow-up, major VTA occurred in 32 patients (25%). At univariable anlysis, major VTA onset (HR 16.8, 95% CI 5.4–52.2, p&lt;0.001) and anteroseptal DGE (HR 3.0, 95% CI 1.3–6.9, p=0.010) were significantly associated with major VTA by 24-month follow-up. Among patients presenting with minor VTA, the only factor significantly associated with the primary endpoint was anteroseptal DGE (3/4 vs. 14/67, p=0.004).

Conclusion

Our preliminary experience suggests that, in patients with clinically-suspected LVAC, major VTA onset and anteroseptal DGE are relevant risk factors for major arrhythmic events by 24-month follow-up.

Funding Acknowledgement

Type of funding sources: None.

Cardiac Toxicity Associated with Cancer Immunotherapy and Biological Drugs

Cancer immunotherapy significantly contributed to an improvement in the prognosis of cancer patients. Immunotherapy, including human epidermal growth factor receptor 2 (HER2)-targeted therapies, immune checkpoint inhibitors (ICI), and chimeric antigen receptor-modified T (CAR-T), share the characteristic to exploit the capabilities of the immune system to kill cancerous cells. Trastuzumab is a monoclonal antibody against HER2 that prevents HER2-mediated signaling; it is administered mainly in HER2-positive cancers, such as breast, colorectal, biliary tract, and non-small-cell lung cancers. Immune checkpoint inhibitors (ICI) inhibit the binding of CTLA-4 or PD-1 to PDL-1, allowing T cells to kill cancerous cells. ICI can be used in melanomas, non-small-cell lung cancer, urothelial, and head and neck cancer. There are two main types of T-cell transfer therapy: tumor-infiltrating lymphocytes (or TIL) therapy and chimeric antigen receptor-modified T (CAR-T) cell therapy, mainly applied for B-cell lymphoma and leukemia and mantle-cell lymphoma. HER2-targeted therapies, mainly trastuzumab, are associated with left ventricular dysfunction, usually reversible and rarely life-threatening. PD/PDL-1 inhibitors can cause myocarditis, rare but potentially fulminant and associated with a high fatality rate. CAR-T therapy is associated with several cardiac toxic effects, mainly in the context of a systemic adverse effect, the cytokines release syndrome.

The novel Mechanical Ventilator Milano for the COVID-19 pandemic

This paper presents the Mechanical Ventilator Milano (MVM), a novel intensive therapy mechanical ventilator designed for rapid, large-scale, low-cost production for the COVID-19 pandemic. Free of moving mechanical parts and requiring only a source of compressed oxygen and medical air to operate, the MVM is designed to support the long-term invasive ventilation often required for COVID-19 patients and operates in pressure-regulated ventilation modes, which minimize the risk of furthering lung trauma. The MVM was extensively tested against ISO standards in the laboratory using a breathing simulator, with good agreement between input and measured breathing parameters and performing correctly in response to fault conditions and stability tests. The MVM has obtained Emergency Use Authorization by U.S. Food and Drug Administration (FDA) for use in healthcare settings during the COVID-19 pandemic and Health Canada Medical Device Authorization for Importation or Sale, under Interim Order for Use in Relation to COVID-19. Following these certifications, mass production is ongoing and distribution is under way in several countries. The MVM was designed, tested, prepared for certification, and mass produced in the space of a few months by a unique collaboration of respiratory healthcare professionals and experimental physicists, working with industrial partners, and is an excellent ventilator candidate for this pandemic anywhere in the world.

Procalcitonin in myocarditis patients: role in aetiology identification and risk stratification

Background

Procalcitonin (PCT) is an established predictor of bacterial infections and sepsis. However, PCT involvement in cardiovascular diseases has been scarcely investigated so far. In particular, no studies at all ever addressed the role of PCT in myocarditis patients.

We aimed at evaluating PCT in myocarditis patients, as a potential biomarker of: a) aetiologic diagnosis; b) prognosis.

Methods

A cohort of 130 consecutive patients with a novel diagnosis of myocarditis confirmed by both endomyocardial biopsy and cardiac magnetic resonance were included in the study. Patients with known bacterial infections or bacterial myocarditis were excluded (n=5). PCT concentration was measured on admission in all patients. Prospective follow-up (FU) was performed every 6 months up to 5 years.

Results

Of 125 patients analyzed (mean age 45±15 years, males 62%, mean LVEF 48±15%), 22 (18%) had fulminant myocarditis (FM). The remaining 103 cases had non-fulminant myocarditis (NFM), including infarct-like presentation and non-malignant arrhythmias. Aetiology was viral or virus-negative in 23 and 102 patients, respectively.

The mean PCT value was 0.44±0.18 mcg/ml, with no significant differences between viral and virus-negative myocarditis (0.43±0.19 vs. 0.44±0.18 mcg/ml, p=0.90).

Baseline PCT concentration was significantly higher in FM patients (0.69±0.21 vs. 0.39±0.16 mcg/ml, p=0.07). Consistently, PCT was higher in patients with LVEF &lt;60% (0.51±0.20 vs. 0.30±0.14 mcg/ml, p=0.03) and in those with elevated (&gt;400 pg/mL) NT-proBNP (0.55±0.19 vs. 0.36±0.17 mcg/ml, p=0.03). As for inflammatory biomarkers, patients with high ESR (&gt;20 mm/h) had also higher PCT values (0.56±0.20 vs. 0.37±0.16 mcg/ml, p=0.03). By converse, no association was found between PCT and CRP abnormal values (p&gt;0.05).

At univariate analysis, high PCT (≥0.20 mcg/ml) was predictive of heart failure recurrence (OR 2.77, 95% CI 1.18–6.48, p=0.02) or arrhythmic cardiac arrest (OR 3.22, 95% CI 1.19–8.71, p=0.02) by discharge, with overall hospitalization prolonged by 10±4 days (p&lt;0.05). Furthermore, patients with high PCT were more prone to myocarditis recurrences (13/80 vs. 4/45, p=0.03) by 5-year FU.

Conclusions

In myocarditis patients, elevated PCT values at presentation are not associated with myocarditis aetiology. Nonetheless, PCT suggests a worse short-term clinical outcome, and also a higher risk of myocarditis recurrences at long-term FU.

Funding Acknowledgement

Type of funding source: None

Immunosuppression and outcomes of myocarditis patients presenting with ventricular arrhythmias

Background

Effects of immunosuppressive therapy (IST) on ventricular arrhythmias (VA) have not been reported in immune-mediated biopsy-proven myocarditis patients. Furthermore, myocarditis arrhythmic risk is still unpredictable. The aim of our study was to evaluate effectiveness of IST on VA in myocarditis patients, and stratify their arrhythmic risk, using clinical and diagnostic features, including serum organ-specific anti-heart (AHA) and antiintercalated-disk autoantibodies (AIDA).

Methods

From a cohort of 498 consecutive patients, we enrolled 255 cases with biopsy-proven virus-negative myocarditis and evidence of VA (VF, VT, NSVT, and Lown's grade ≥2 PVC) at index hospitalization. Serum AHA and AIDA were detected by a standardised indirect immunofluorescence technique. Whenever accepted and non-contraindicated, IST was started. Controls (IST-) were chosen after 1:1 matching to IST+ cases by age, gender, ethnicity, left ventricular ejection fraction, VA type, and treatment. Prospective follow-up (FU), occurred at defined timepoints.

Results

58 matched patient couples (42±13 y, 67% males, 50% IST+) were analyzed in the main study cohort. Overall, 28 (24%) had VT, and 62 (53%) were discharged with ICD. IST duration was 12±1 months. No patients died and no serious complications from IST occurred. By 24-month FU, major VA occurred in 6 IST+ vs. 10 IST- patients (p=0.420), with no cases of VT following IST termination. As compared to IST- ones, IST+ patients showed a significant reduction in NSVT and PVC burden, as well as an improvement in clinical, laboratory and imaging findings (all p&lt;0.05). Major VA onset and positive AIDA status were independently associated with major VA at FU (HR 14.2, 95% CI 2.9–68.7, and 8.0, 95% CI 2.6–25.2, respectively, both p&lt;0.001). Furthermore, in the whole study population (N=255), IST played as an independent protective factor from major VA (HR 0.3, 95% CI 0.2–0.7, p=0.005) at 38±21 months FU.

Conclusions

In immune-mediated virus-negative myocarditis patients presenting with VA, IST is feasible and effective on NSVT and PVC burden, as well as on structural, laboratory and imaging endpoints. Short-term effects are limited on major VA, which were independently associated with major arrhythmic onset and positive AIDA, in keeping with the proposed etiopathogenetic involvement of autoimmunity in virus-negative myocarditis.

Funding Acknowledgement

Type of funding source: None

Soft X-ray induced radiation damage in thin freeze-dried brain samples studied by FTIR microscopy

In order to push the spatial resolution limits to the nanoscale, synchrotron-based soft X-ray microscopy (XRM) experiments require higher radiation doses to be delivered to materials. Nevertheless, the associated radiation damage impacts on the integrity of delicate biological samples. Herein, the extent of soft X-ray radiation damage in popular thin freeze-dried brain tissue samples mounted onto Si₃N₄ membranes, as highlighted by Fourier transform infrared microscopy (FTIR), is reported. The freeze-dried tissue samples were found to be affected by general degradation of the vibrational architecture, though these effects were weaker than those observed in paraffin-embedded and hydrated systems reported in the literature. In addition, weak, reversible and specific features of the tissue-Si₃N₄ interaction could be identified for the first time upon routine soft X-ray exposures, further highlighting the complex interplay between the biological sample, its preparation protocol and X-ray probe.

FRI0183 DISTINCTIVE TRAITS OF MYOCARDIAL INFLAMMATION IN PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS: A MULTICENTRE STUDY

Background:

Myocarditis is an infrequent but potentially life-threatening inflammatory disorder and might be part of the spectrum of systemic lupus erythematosus (SLE). Little is known about the clinical and histologic features of myocarditis in SLE, especially compared to other forms of myocarditis.

Objectives:

to test for potential distinctive traits among myocarditis in SLE (MyoSLE), SLE without myocarditis (OnlySLE) and myocarditis without SLE (OnlyMyo)

Methods:

Patients with MyoSLE were identified from three centres and compared with 231 cross-sectionally enrolled patients with OnlySLE and 87 patients with OnlyMyo. MyoSLE patients were split into two groups based on myocarditis onset within (early onset) vs after (late onset) the first year from SLE diagnosis. OnlySLE patients were dichotomised in the same way based on disease duration at time of enrolment. Demographics and general clinical features were collected retrospectively. SLE disease activity index 2000 (SLEDAI-2K), SLE International Collaborating Clinics/American College of Rheumatology damage index (SDI), clinical and laboratory features were collected at time of myocarditis onset in MyoSLE and at enrolment in OnlySLE. Quantitative data are expressed as median [interquartile range].

Results:

Fourteen MyoSLE patients were identified, 50% with early onset. Women were equally frequent among MyoSLE (71%) and OnlySLE patients (87%) and less frequent in the OnlyMyo group (43%; p<0.001). Age was comparable among groups. Clinical features at presentation, including left ventricular ejection fraction, were similar between MyoSLE and OnlyMyo, although the former had higher levels of pro-brain natriuretic peptide (1.1 [0.4-1.8] vs 0.1 [0.1-0.5] ng/ml; p=0.004). Patients with MyoSLE also had a lower frequency of left ventricle lateral wall involvement (36 vs 68%; p=0.035) and of oedema (20 vs 71%; p=0.036) and necrosis (0 vs 64%; p=0.009) at biopsy. Antiphospholipid antibodies (aPL) were more frequent in MyoSLE (57%) compared to both OnlyMyo (16%; p=0.003) and OnlySLE (28%; p=0.031). Compared to OnlySLE, patients with MyoSLE also had a higher prevalence of aPL-syndrome (APS: 36 vs 7%; p=0.003), neuropsychiatric (NPSLE: 43 vs 19%; p=0.039) and gastrointestinal manifestations (21 vs 5%; p=0.045). Early and late onset patients had similar demographics and clinical features and did not differ from patients with OnlySLE with similar disease duration in terms of SLEDAI-2K and SDI. Late onset MyoSLE patients had a higher prevalence of NPSLE (57 vs 18%; p=0.026) and APS (57 vs 7%; p=0.001) and higher C-reactive protein levels (6 [2-12] vs 1[0-4] mg/l; p=0.024) compared to OnlySLE patients with the same disease duration.

Conclusion:

Demographics of patients with MyoSLE are more similar to patients with OnlySLE than to OnlyMyo patients. MyoSLE might have distinct histological and pathogenic features compared to OnlyMyo. Patients with MyoSLE show similar patterns of disease activity and accrued damage at time of myocarditis onset compared to patients with OnlySLE with the same disease duration but might diverge later on in SLE course. aPL are frequent in MyoSLE and might both contribute to the pathogenesis of myocardial inflammation and account for the high prevalence of NPSLE and APS, especially in late onset cases.

References:

[1]Gartshteyn Y et al., Lupus, 2020

[2]Thomas G et al., J Rheumatol, 2017

[3]Peretto G et al., Int J Cardiol, 2019

[4]McDonnell T et al., Blood Rev, 2019

Disclosure of Interests:

Giuseppe Alvise Ramirez: None declared, Maria Gerosa: None declared, Giacomo De Luca Speakers bureau: SOBI, Novartis, Celgene, Pfizer, MSD, Lorenzo Beretta Grant/research support from: Pfizer, Simone Sala: None declared, Giovanni Peretto: None declared, Luca Moroni: None declared, Francesca Mastropaolo: None declared, adriana cariddi: None declared, Silvia Sartorelli: None declared, Corrado Campochiaro Speakers bureau: Novartis, Pfizer, Roche, GSK, SOBI, Enrica Bozzolo: None declared, Roberto Caporali Consultant of: AbbVie; Gilead Sciences, Inc.; Lilly; Merck Sharp & Dohme; Celgene; Bristol-Myers Squibb; Pfizer; UCB, Speakers bureau: Abbvie; Bristol-Myers Squibb; Celgene; Lilly; Gilead Sciences, Inc; MSD; Pfizer; Roche; UCB, Lorenzo Dagna Grant/research support from: The Unit of Immunology, Rheumatology, Allergy and Rare Diseases (UnIRAR) received unresctricted research/educational grants from Abbvie, Bristol-Myers Squibb, Celgene, Janssen, Merk Sharp & Dohme, Mundipharma Pharmaceuticals, Novartis, Pfizer, Roche, Sanofi-Genzyme, and SOBI., Consultant of: Prof Lorenzo Dagna received consultation honoraria from Abbvie, Amgen, Biogen, Bristol-Myers Squibb, Celltrion, Novartis, Pfizer, Roche, Sanofi-Genzyme, and SOBI.

Assessing the decoupling of economic growth from environmental impacts in the European Union: A consumption-based approach

Pursuing a responsible and sustainable development, the United Nations urged to decouple economic growth from environmental impacts. Several European Union (EU) policies have been implemented towards such goal. Although multiple authors have evaluated the decoupling of the economic growth from the resource use or environmental concerns, the environmental assessment mostly focused on pressures rather than impacts, and used single indicators assumed to be a proxy of the overall effects on the environment. Furthermore, no studies were found using a process-based life cycle approach to quantify the environmental impacts of consumption. To solve such research gap, this paper assesses the decoupling in the EU focusing on potential environmental impacts, complementing a production-based approach with two options for accounting for the impacts of consumption. The aim of this paper is to evaluate the decoupling of the economic growth (in terms of Gross Domestic Product) from the environmental impacts due to EU-28 consumption, assessed by means of life cycle assessment (LCA). The decoupling is then assessed in impact terms rather than limited to pressures by using the Environmental Footprint (EF2017) indicators, which allows assessing 16 different impacts. The Consumption Footprint indicator quantified the environmental impacts of EU apparent consumption, including the territorial impacts (Domestic Footprint) and the embodied impacts in both imports and exports (Trade Footprint). The inventory of pressures for the trade component is compiled either with a bottom-up approach (process-based LCA of representative traded goods) or a top-down approach (input-output-based LCA). Methodological aspects influencing the decoupling assessment and the resulting outputs are presented and discussed. According to the results, the environmental impacts of EU-28 consumption showed decoupling during the last decades (2005-2014), between relative to absolute decoupling depending on the inventory modeling approach taken. Some countries showed higher decoupling levels than others displaying a heterogeneous map of EU-28 decoupling, which was led by acidification, particulate matter, land use and eutrophication impacts. Notwithstanding current limitations, the assessment of decoupling using consumption-based environmental indicators is very promising for supporting policy-making towards addressing the actual impacts driven by the EU production and consumption system.

P5557Cardiac autoantibodies and ventricular arrhythmias in patients with biopsy-proved myocarditis

Background

Cardiac autoandibodies have been associated with dilatative cardiomyopathy in subjects with inflammatory heart disease. However, their association with ventricular arrhythmias (VA) in patients with autoimmune myocardits has never been investigated so far.

Purpose

To evaluate the association between cardiac autoantibodies and both baseline and FU VA in patients with a de novo diagnosis of biopsy-proved autoimmune myocarditis.

Methods

We enrolled 44 consecutive patients (59% males, mean age 44±13y, mean LVEF 50±10%) presenting with symptomatic VA (VF, VT, NSVT, >1ehz746.0501 PVC/24h) and a de novo diagnosis of biopsy-proved autoimmune myocarditis according to the ESC criteria. Serum anti-heart (AHA) and anti-intercalated disk (AIDA) autoantibodies were assessed at a referral center at the time of the index hospitalization. Complete baseline data, including ECG, arrhythmia telemonitoring, echocardiogram, cardiac magnetic resonance (CMR) and blood biomarkers (T-troponin, NT-proBNP) were collected. The endpoint of the study was the occurrence of major VA (VT, VF, appropriate ICD shocks) at 5y FU, as assessed by 2/y Holter ECG monitoring and (when applicable) ICD interrogation.

Results

At baseline evaluation, 24 (55%) and 23 patients (52%) were AHA+ and AIDA+, respectively. Clinical onset with major VA was documented in 24 patients (55%): 9 AHA+ vs. 15 AHA- (p=0.017) and 13 AIDA+ vs. 11 AIDA- (p=0.547). At presentation, no significant differences were found between AHA+ vs. AHA- and AIDA+ vs. AIDA- patients in LVEDV, LVEF, T-troponin and NT-proBNP values (all p=n.s.). Positive (2/3) Lake Louise criteria at CMR were found in 33 patients (75%; p=n.s. among different subgroups). Before discharge, 27 subjects (61%) underwent ICD implant. Optimal medical treatment was started in all of the cases, with no significant differences in betablockers, antiarrhythmic drugs and immunsuppressive therapy, among different subgroups (all p=n.s.). Overall, 10 patients (23%) experienced major VA by 5y FU: 3 AHA+ vs. 7 AHA- (p=0.147) and 9 AIDA+ vs. 1 AIDA- (p=0.013). In particular, 18 events were documented (range 1–3 episodes per patient at 2.2±1.7 y mean FU), including 3 VT episodes and 15 appropriate ICD shocks. Taking together baseline and FU data, multiple (>1) major VA episodes occurred in 8 patients: 3 AHA+ vs. 5 AHA- (p=0.436) and 8 AIDA+ vs. 0 AIDA- (p=0.005). Of note, 3/3 AHA+ patients with multiple major VA espisodes were also AIDA+ (double positivity).

Conclusion

In biopsy-proved autoimmune myocarditis presenting with VA, major VA occurrence by 5y FU, as well as arrhythmias recurrences, are more common among AIDA+ patients. By converse, none of the isolated AHA+ cases experienced multiple episodes of major VA. These findings may suggest distinct pathophysiological mechanisms involving the different molecular targets of cardiac autoimmunity.

Acknowledgement/Funding

None

P5695Catheter ablation of ventricular tachycardia in patients with acute vs. previous myocarditis

Background

Ventricular tachycardias (VT) may occur late after myocarditis, as well as in the acute inflammatory phase of the disease. However, the role of catheter ablation (CA) in preventing VT recurrences in patients with acute (AM) vs. previous myocarditis (PM) has never been investigated so far.

Purpose

To evaluate the results of CA performed in patients presenting with VA and biopsy-proved myocarditis at different inflammatory stages.

Methods

We enrolled 46 consecutive patients (74% males, mean age 43±12y, mean LVEF 46±9%) with myocarditis and VT at index hospitalization. Based on endomyocardial biopsy and cardiac magnetic resonance (CMR) results, the patients were divided into AM and PM groups: in AM group, myocarditis was biopsy-proved, according to the ESC criteria; PM patients had a history of biopsy-proved myocarditis more than 12 months before, with no current signs of active inflammation (negative biopsy according to the ESC criteria; nonischaemic LGE at CMR with negative Lake-Louise criteria; absence of unexplained troponin abnormalities). ICD were implanted upon clinical indications. All of the patients underwent electroanatomical mapping (EAM) and VT CA. During 3 (2.5–3.5)y FU, VT recurrences were evaluated by 2/y Holter ECG and ICD interrogation.

Results

At baseline, 23 patients (50%) had AM, and 23 PM. Overall, 16 AM and 21 PM patients underwent ICD implant (p=n.s.). The clinical VT was monomorphic in 22 AM and 23 PM patients, respectively (p=n.s.) with a dominant right-bundle branch block with superior axis (RS) morphology in both groups (16 AM vs. 17 PM cases, p=n.s.). However, RS morphology was associated with left ventricular inferoposterior LGE at CMR in 9/16 AM vs. 17/17 PM patients (p=0.003). Similarly, inferoposterior localization of low-voltage areas at EAM was found in 11/16 AM vs. 17/17 PM patients (p=0.018). Furthermore, CMR showed a greater LGE transmural extension in AM patients (65±19%) as compared to PM ones (40±25%, p<0.001). Epicardial EAM and CA were performed in 14 AM vs. 15 PM patients, with endocardial-only approach adopted in the remaining cases (p=n.s.). VT CA was defined as successful (class A) in all of the subjets. However, during FU VT recurrences were documented in 7/23 AM vs. 0/23 PM patients (p=0.009). Four AM cases underwent redo CA late after myocarditis (1.5±0.3y after index hospitalization), with no further VT recurrences in FU.

Conclusion

In myocarditis patients presenting with VT, CA results are significantly better in PM cases as compared to AM ones. These findings are consistent with the different underlying substrate, and suggest the best role for ablation strategy after myocarditis healing.

Acknowledgement/Funding

None

Biodiversity impacts due to food consumption in Europe

Food security and biodiversity conservation are closely interconnected challenges to be addressed to achieve a sustainable food system on a global scale. Due to the complex nature of food production and consumption system, quantifying the impacts of food supply chains on biodiversity is challenging. Life cycle assessment (LCA) allows for systematically addressing environmental impacts along supply chains, representing a reference methodology that can be applied for assessing food systems. In the present study, 32 representative food products of consumption in the European Union (EU) were selected and their environmental impacts calculated through a process-based LCA. The potential contribution of EU food consumption to the current biodiversity decline has been evaluated adopting both midpoint and endpoint indicators. A comparison of the impact drivers was performed. Meat products, the underpinning land use for agricultural purposes, and climate change represent the main hotspots of impacts on biodiversity. Notwithstanding several drivers of biodiversity loss can be accounted for with LCA, the evidence of the increasing biodiversity decline on both a European and a global scale indicates that the assessment system should be further expanded, especially for what concerns refining impact categories such as ecotoxicity, and including resource overexploitation, and impact due to invasive species. This study illustrates: how far the current LCA based impact assessment framework may help to address the drivers of biodiversity loss; which are the main uncertainties associated to results stemming from the application of different endpoint methods; which aspects need to be elaborated further to ensure a comprehensive assessment of biodiversity impacts due to food production and consumption.

First demonstration of antimatter wave interferometry

Interference of matter waves is at the heart of quantum physics and has been observed for a wide range of particles from electrons to complex molecules. Here, we demonstrate matter wave interference of single positrons using a period-magnifying Talbot-Lau interferometer based on material diffraction gratings. The system produced high-contrast periodic fringes, which were detected by means of nuclear emulsions capable of determining the impact point of each individual positron with submicrometric resolution. The measured energy dependence of fringe contrast in the range of 8 to 16 keV proves the quantum-mechanical origin of the periodic pattern and excludes classical projective effects, providing the first observation to date of antimatter wave interference. Future applications of this interferometric technique include the measurement of the gravitational acceleration of neutral antimatter systems exploiting the inertial sensing capabilities of Talbot-Lau interference.

Updated clinical overview on cardiac laminopathies: an electrical and mechanical disease

Cardiac laminopathies, associated with mutations in the LMNA gene, encompass a wide spectrum of clinical manifestations, involving electrical and mechanical alterations of cardiomyocytes. Thus, dilated cardiomyopathy, bradyarrhythmias and atrial or ventricular tachyarrhythmias may occur in a number of combined phenotypes. Nowadays, some attempt has been made to identify clinical predictors for the most life-threatening complications of LMNA-associated heart disease, i.e. sudden cardiac death and end-stage heart failure. The goal of this manuscript is to combine the most recent evidences in an updated review to show the state-of-the-art of such a complex disease group. This is supposed to be the starting point to collect more data and design new ad hoc studies to identify clinically useful predictors to stratify risk in mutation carriers, including probands and their asymptomatic relatives.

Lipid-based nanovesicles for nanomedicine

Multifunctional lipid-based nanovesicles (L-NVs) prepared by molecular self-assembly of membrane components together with (bio)-active molecules, by means of compressed CO₂-media or other non-conventional methods lead to highly homogeneous, tailor-made nanovesicles that are used for advanced nanomedicine. Confocal microscopy image of siRNA transfection using L-NVs, reprinted with permission from de Jonge,et al.,Gene Therapy, 2006,13, 400–411.

Morphometric analysis and lymph node yield in laparoscopic complete mesocolic excision performed by supervised trainees

BACKGROUND

Complete mesocolic excision with central vascular ligation (CME) produces an optimal colonic cancer specimen. The ability of expert laparoscopic surgeons to produce equivalent specimens is unknown.

METHODS

Fresh specimen photographs and clinicopathological data from patients undergoing laparoscopically assisted CME at St Mark's Hospital, Harrow, were submitted for independent pathological review. Surgery was performed by a mixture of consultant specialists and trainees under consultant specialist supervision, between February 2010 and July 2011. The planes of surgery were graded and tissue morphometry was performed using standard methods. The results were compared with published data from open CME and non-CME surgery.

RESULTS

In total, 69 patients were identified, and in 96 per cent resection was performed completely or partially by surgical trainees. Laparoscopic CME produced a similar specimen to open CME. The laparoscopic mesocolic plane resection rate was similar to that for open surgery (90 versus 88 per cent). The distance between the bowel wall and site of vascular division was similar for laparoscopic and open right-sided CME (92 versus 95 mm respectively). The corresponding values for left-sided CME were also similar (103 versus 107 mm). Compared with values from two non-CME series, laparoscopic CME had a higher mesocolic plane rate (90 versus 40 and 48 per cent), and resected more tissue between the bowel wall and the vascular division (right-sided: 92 versus 72 and 76 mm; left-sided: 103 versus 85 and 70 mm). The lymph node yield remained low following laparoscopic CME compared with open CME (median 18 versus 32; P < 0·001) and identical to that of non-CME surgery (median 18).

CONCLUSION

Laparoscopic CME can be performed to the same standard as open surgery by supervised trainees. However, this did not increase the lymph node yield.

Fistulotomy in the tertiary setting can achieve high rates of fistula cure with an acceptable risk of deterioration in continence

INTRODUCTION

Surgery is the mainstay of treatment of anal fistulas. Low fistulas are often laid open, but higher fistulas present a more difficult problem. Patient choice centres on a compromise between risk of recurrence and risk of impairment of continence. We aimed to determine the efficacy and safety of fistulotomy at a tertiary referral centre, in particular the additional risk of impairment of continence following fistulotomy of the often recurrent, multiply-operated patients seen.

METHODS

Patients undergoing surgery under the senior author (RKSP) for an anal fistula during the study period (2005-2006) were identified, and a thorough review of the patients' clinical records was undertaken. Demographic, fistula anatomy, treatment and follow-up data were obtained.

RESULTS

Eighty-four patients underwent either fistulotomy (50), insertion of permanent loose (drainage) seton (28) or EUA with or without drainage of abscess. Mean length of follow up was 11 months (SD 14.22). In the fistulotomy group, we found an overall success rate of 93 %. Secondary extensions were associated with failure to achieve cure (P = 0.008). Nine patients (20 %) suffered deterioration in continence after surgery. A longer time to referral was associated with impaired final continence. In the group referred from a surgeon in secondary care, 91 % of patients were cured, and continence impairment (mostly minor) rose from 32 % at referral to 40 % after surgery.

CONCLUSIONS

We have shown that it is safe and reasonable to offer fistulotomy to appropriate patients despite previous surgery and within the tertiary setting. By so doing, a very high rate of healing can be achieved in patients who have previously failed. The additional risk of impairment of continence is around one in five, and in the majority will represent only minor incontinence.