Pregnancy in Patients with the Fontan Operation

Improved survival rates for patients with a Fontan circulation has allowed more women with this complex cardiac physiology to contemplate pregnancy. However, pregnancy in women with a Fontan circulation is associated with a high risk of adverse maternal and fetal outcomes, high rates of miscarriage and preterm delivery. Factors associated with a successful pregnancy outcome are: younger age, normal body weight, absence of significant functional limitation, no Fontan-related complications, and well-functioning single ventricle physiology. Appropriate care with timely preconception counselling and regular, frequent clinical reviews by a multidisciplinary team based at a tertiary centre, improves the chance of a successful pregnancy. Empowerment of patients with education on their specific congenital cardiac condition and its projected trajectory, helps them make informed choices regarding their health, reproductive choices and assists them to achieve their life goals.

Renal dysfunction: a predictor of adverse outcomes in ACHD patients with acute decompensated heart failure

Background

Renal dysfunction (RD) is a predictor of adverse outcomes in patients with acquired heart failure (HF). Studies in adult congenital heart disease (ACHD) have demonstrated the link between RD and increased mortality. However, there is a paucity of data regarding the prognostic significance of RD in ACHD and HF. We assessed the impact of RD on outcomes in ACHD patients presenting with acute decompensated HF requiring intravenous (IV) diuresis in a tertiary centre between 2010–2021.

Methods

This was a retrospective analysis on RD and outcomes during the index hospital admission and after discharge. Chronic kidney disease (CKD) was defined as an eGFR <60mL/min/1.73 m2 using the MDRD equation. Cox regression analysis was used to identify predictors of death after discharge.

Results

We included 176 HF admissions, 76 (43.2%) female, age 47.7±14.5 years. Complex CHD was present in 50.6%. The most frequent underlying congenital heart defects were: transposition of the great arteries (including congenitally corrected, 19.9%), univentricular (14.2%), and tetralogy of Fallot (13.6%). Eisenmenger syndrome was present in 18.8%, a systemic right ventricle in 22.2%, 40.9% had pulmonary arterial hypertension (PAH), and 38.1% were cyanotic. At the time of the index admission 92 (52.3%) had RD (eGFR <60 mL/min/1.73 m2 and/or serum creatinine >88 μmol/L), 63 (38.2%) had a history of CKD. Patients with RD on admission were older (49.8 [42.3–60.9] vs. 46.0 [33.8–53.6] years, p=0.02) and more likely to have a history of arrhythmia (71.7% vs. 53.6%, p=0.02), but did not differ to those without RD in terms of diabetes mellitus or systemic hypertension. Admission BNP was higher in patients with RD (594 [258–1216] vs. 354 [158–633] ng/L, p=0.01). Patients with RD were more likely to have at least moderate systemic (31.8% vs. 11.8%, p=0.005) or pulmonary (58.4% vs. 36.4%, p=0.01) ventricular dysfunction. They were also more likely to have systemic ventricular dilatation (28.6% vs. 11.8%, p=0.02) or a larger RA area (29 [21–34] vs. 21 [16–31] cm2, p=0.008). Inpatients with RD required higher doses of IV furosemide (160 [80–200] vs. 80 [70–160] mg, p=0.03) and there was a trend for more frequent inotropic support (19.6% vs. 8.3%, p=0.06). In-hospital mortality was relatively low (4.5%), however, 94 (56.0%) patients died and 73 (43.5%) were rehospitalised for HF at a median follow-up of 2.8 [0.01–12.0] years. CKD (HR 2.43, 95% CI: 1.59–3.71, p<0.0001) and RD on admission (HR 1.7, 95% CI: 1.13–2.58, p=0.01) were strong predictors of death (Figure 1). On multivariable Cox analysis, PAH, CKD, and peak inpatient diuretic dose remained predictive of mortality.

Conclusions

ACHD patients admitted with acute decompensated HF are a high-risk cohort for acute re-admission and mortality. Preexisting RD and need for high dose IV diuretics conveys an even worse prognosis. Earlier interventions based on evidence of RD in ACHD may modulate this spiral trajectory and warrants further investigation.

Funding Acknowledgement

Type of funding sources: None.

Predictors of adverse clinical outcome after hospitalisation for decompensated heart failure in ACHD patients

Background

As the ACHD population ages, an increasing number of patients are being admitted for heart failure. Management is complicated by the limited evidence on pharmacological and other therapies and lack of risk stratification tools. Improved surgical and medical treatment options in this patient cohort has improved life expectancy.

Purpose

Assess the mortality and rate of rehospitalisation in ACHD patients following admission with decompensated HF and identify clinical predictors of outcome.

Methods

All ACHD patients admitted for HF requiring IV diuresis from February 2016 to December 2020 in a single tertiary centre were included. Cox analysis was used to identify predictors of death after the index admission.

Results

91 patients were included: 44.0% female, 45.8±14.2 years. The most frequent underlying diagnoses were: 15.4% with primary valve or left ventricular outflow tract disease, 12.1% with transposition of the great arteries post-atrial switch, 9.9% with tetralogy of Fallot and 30.8% had a systemic right ventricle. Most (56.7%) patients had CHD of “great” complexity according to the Bethesda classification, whereas no patients had “simple” CHD. Cyanosis was present in 26.4%.

Heart failure was predominantly related to systemic ventricular dysfunction in 35.2%, subpulmonary ventricular dysfunction in 25.3%, biventricular dysfunction in 24.2% and univentricular dysfunction in 15.4%. Pulmonary hypertension was present in most (58.2%) patients, only half (46.0%) of these had pre-capillary pulmonary hypertension.

On admission, approximately half of patients were on standard heart failure therapy: 48.4% ACE-inhibitors or angiotensin receptor blockers, 54.9% beta-blockers, 54.9% mineralocorticoid receptor antagonists and 2% on sacubitril/valsartan.

In-hospital mortality was only 3.3% in this high-risk population. During a median follow-up of 22.1 [0.2–58.4] months, 37.5% patients were rehospitalised for HF and 37.5% patients died (22.7% mortality at 1 year). On univariable Cox analysis, the following parameters were predictors of mortality: pulmonary hypertension, cyanosis, unoperated or palliated CHD, chronic kidney disease (CKD), hyponatraemia, mineralocorticoid receptor antagonist use on admission, admission BNP>350ng/L and a maximum daily inpatient loop diuretic requirement >160mg (furosemide equivalents). On multivariable Cox analysis, pulmonary hypertension, cyanosis, hyponatraemia and CKD were independent predictors of mortality; patients with ≥2 of these risk factors had an 8-fold higher mortality (figure).

Conclusion

ACHD patients hospitalised for decompensated HF have a poor outlook with a quarter of patients dying within a median <2 years from discharge. We present clinical parameters that can identify patients at high risk of an adverse outcome who should be targeted for aggressive monitoring and advanced HF therapies, including transplantation.

Funding Acknowledgement

Type of funding sources: None. Figure 1

Cardiovascular outcomes in women with the highest classification of maternal cardiovascular risk in pregnancy

Introduction

The modified world health organization (mWHO) classification of maternal risk is used to estimate morbidity and mortality in pregnant women with cardiovascular disease. Those in the highest risk category (mWHO Risk Class IV) are at greatest risk. Pregnancy is contraindicated in this patients.

Methods

This was a retrospective review of pregnant women classified as mWHO risk class IV, who were managed in a tertiary joint cardiac-obstetric pathway between 2008 and 2018.

Results

In total, there were 35 pregnancies in 30 women with the highest cardiovascular risk for adverse maternal outcomes. The mean maternal age at delivery was 29.3±5.2 years. Eleven (36%) patients were diagnosed with cardiovascular disease during pregnancy. Fourteen had a form of pulmonary arterial hypertension (46%), 6 (20%) had severe systemic ventricular dysfunction, 4 (13%) had severe mitral or aortic stenosis, 4 (13%) had aortic dilatation or inherited aortopathy, 1 (3%) had a history of peri-partum cardiomyopathy and 1 (3%) had severe native coarctation of the aorta. In the 30 pregnancies followed up in our centre, 29 (96%) were single foetus pregnancies and 1 (4%) was a twin pregnancy. There were 30 live births, 1 foetus was lost in the twin pregnancy. Of these 29 (96%) patients underwent elective caesarean section and 1 (4%) emergency caesarean section. Cardiovascular complications occurred in 18 (60%) women. Of these, 5 (28%) had atrial arrhythmias during pregnancy, 6 (33%) had worsening of pulmonary hypertension, 6 (33%) had decompensated heart failure. Three women had interventions during pregnancy: 1 had percutaneous intervention for coarctation of aorta due to foetal and maternal compromise, 1 had electrophysiological ablation for atrial arrhythmias to improve systemic ventricular function and 1 had an electrical cardioversion for atrial fibrillation. There were no deaths during pregnancy or in the peripartum period. One patient who presented at 34 weeks gestation with severe peripartum cardiomyopathy required early inotropic support followed by extracorporeal membrane oxygenation (ECMO) support post-delivery, died at 2 months post-partum.

Conclusions

With appropriate pre-pregnancy optimization, antepartum surveillance individualised peripartum care plans and multidisciplinary care throughout pregnancy, women at the highest risk for cardiovascular outcomes can have successful pregnancies, although the risk of cardiovascular complications remains high.

Funding Acknowledgement

Type of funding sources: None.

Patients with Fontan circulation beyond the fourth decade of life

Background

The survival rate after Fontan procedure is improving and many of these patients now survive well into adulthood. Data on the late morbidity and mortality of Fontan patients in their fourth decade of life are lacking.

Purpose

To evaluate the late outcome of adult patients with Fontan circulation who have survived beyond 35 years.

Methods

Data were collected retrospectively on consecutive patients with a Fontan circulation ≥35 years between 2005 and 2019. Baseline (at 35th birthday) and follow-up data includes functional class, blood tests, history of arrhythmia, heart failure (HF), thromboembolism, Fontan related liver disease (FLD), protein losing enteropathy (PLE) and plastic bronchitis. Echocardiographic data on systemic atrioventricular valve (SAVV) regurgitation and ventricular function were also analysed.

Results

61 patients were included (29, 47.5% female). Tricuspid atresia was the most common underline anatomy (29,47.5%) and the median age at Fontan procedure was 12 [8.0–19.0] years. 34 (56%) patients had an atrio-pulmonary connection Fontan and 15 (24.5%) total cavo-pulmonary connection (86.7% lateral tunnel and 13.3% extra-cardiac conduit), 10 (16%) a Bjork Fontan and 2 (3%) a Kawashima procedure. At baseline 40 (66%) patients were in NYHA class II or III, 7 (11%) had a moderate or severely impaired ventricular function and 12 (20%) had at least moderate SSAV regurgitation. At baseline, 35 (57.4%) patients had experienced at least one arrhythmia, 7 (11.4%) patients had a history of atrial thrombosis or thromboembolic events and 2 (3.3%) of PLE. At a median follow-up of 6.4 [2.9–11.3] years, 11 (18%) patients died, 7 of chronic HF, 1 hepatic carcinoma, 1 sepsis, 1 pulmonary embolism, 1 malignancy (1 cause unknown). During follow-up, 28 (46%) patients had a new episode of atrial arrhythmia, 23 (38%) developed FLD and 2 (3.3%) PLE. 9 (15%) required at least one admission for HF. 2 (3.3%) patients experienced worsening of their ventricular function and 7 (11.4%) of their SAVV regurgitation. On univariable analysis, a baseline diagnosis of PLE (HR 15.23, 95% CI:2.77–83.86, p=0.002), HF (HR 6.18, 95% CI:1.74–21.99, p=0.005), atrial arrhythmia (HR 4.99, 95% CI:1.07–23.21, p=0.04), lower serum albumin (HR 1.14, 95% CI:1.06–1.23, p=0.0006), lower iron levels (HR 1.31, 95% CI:1.02–1.68, p=0.04) and a higher urea (HR 1.18, 95% CI:1.04–1.34, p=0.01) were associated with death or heart transplantation. On bivariable analysis, lower serum albumin was stronger than all other univariable predictors.

Conclusions

Adult Fontan survivors are a high risk population with significant morbidity and mortality driven primarily by HF and other long-term complications of the Fontan operation. The predictors of outcome in this cohort reflects the chronic low cardiac output state and systemic venous hypertension. Vigilance is required to identify patients who may benefit of haemodynamic optimization and close monitoring for Fontan-related complications.

Funding Acknowledgement

Type of funding source: None

Long term follow-up after pregnancy in Fontan patients

Background

Patients with single ventricle physiology who have benefited from the Fontan procedure are reaching childbearing age. In this population, complications are common around pregnancy, but the long term effect of pregnancy is unclear.

Purpose

To evaluate functional and structural changes several years after pregnancy in patients with Fontan circulation.

Methods

Women with Fontan circulation who had a pregnancy beyond the 20 weeks of gestation followed at our centre between 2005–2019 were included. The following data were collected before pregnancy and at the last follow up (f-up): cardiac anatomy, type of Fontan procedure, resting O2 saturation (O2sat), NYHA class, systemic atrioventricular valve (SAVV) regurgitation, ventricular function, history of arrhythmias, heart failure (HF), thromboembolism, Fontan-related liver disease (FLD), protein-losing enteropathy (PLE), plastic bronchitis and cardiopulmonary test data.

Results

12 patients had 18 pregnancies, giving birth to 17 live newborns (1 newborn death at 24 weeks of gestation). 7 (58.3%)patients had a total cavo-pulmonary connection, 3 (25%)an atrio-pulmonary connection and 2 (16.7%)a Bjork type Fontan. Tricuspid atresia was the most common anatomy (6, 50%). Before pregnancy, O2sat was 95.4±1.9%and all patients were in NYHA class I or II. All patients (12, 100%)had a normal or mildly impaired ventricular function and 3 (25%)had a moderate or severe SAAV regurgitation. 6 (50%)patients had 2 pregnancies. Mean age at first pregnancy was 29.9±4.4 years. Cardiac events occurred in 7 (38%)pregnancies, most commonly atrial arrhythmia (4, 57%), 2 (16.6%)patients developed new cyanosis and 1 had a thromboembolic event. No maternal death occurred and 1 patient had severe haemorrhage. After a mean f-up of 84±48 months, there was no significant worsening in O2sat (94.3±3.1 at f-up, p=1) and all patients remained in NYHA class I or II (12, 100%, p=1). At f-up all patients (12, 100%)continued to have a normal or mildly impaired ventricular function (p=1) and there was no significant worsening in the SAAV regurgitation (3 patients with moderate or severe regurgitation, p=1). 3 (25%)patients developed FLD (p=0.3), 3 (25%) a new episode of atrial arrhythmia (p=0.3). There were no significantly differences in peak VO2 (22.5±3.8 pre-pregnancy, 22.8±5.5 at f-up, p=0.4) and VE/VCO2 slope (34.9±11.2 pre-pregnancy, 36.3±11.8 at f-up, p=0.2)before pregnancy and during f-up.

Conclusions

In this small cohort of Fontan patients who successfully completed at least 1 pregnancy, there was no significant decline in functional or structural cardiac parameters long term after delivery.

Funding Acknowledgement

Type of funding source: None

Strong association between cardio-pulmonary exercise parameters and mortality in adults with transposition of the great arteries and a systemic right ventricle

Introduction

Patients with transposition of the great arteries (TGA) who underwent atrial switch repair (ASR, Senning or Mustard) and patients with congenitally corrected TGA (ccTGA) have a morphological right ventricle in the systemic position. Patient with a systemic right ventricle (SRV) are prone to exercise intolerance and have a significantly worse survival compared to the general population. Risk stratification is an important component of their management and routine clinical assessment.

Purpose

To describe the severity and mechanisms of exercise limitation in patients with a SRV, and its relation to mortality.

Methods

All SRV patients who underwent a cardiopulmonary exercise test (CPET) in a tertiary centre from 2000–2019 were included. Demographics, clinical and imaging data were collected around the time of CPET. Cox survival analysis was used to assess the association between exercise parameters and mortality.

Results

A total of 262 patients underwent at least one CPET during the study period. Mean age at CPET was 37.4±12 and 154 (58.8%) were male. The majority of patients had TGA with ASR (150, 57.3%), while 112 (42.7%) had ccTGA. The majority of patients were in NYHA class I (36%) or II (36%). Moderate or severe right ventricular dysfunction was present in 188 (78.0%), while 59 (26.6%) patients had moderate or severe TR. Baseline oxygen saturation was 96±4% and median BNP was 71 [37–140] ng/L. Co-existent congenital lesions were present in almost one half (48.8%) of patients, including pulmonary stenosis (31,7, 12.1%) and ventricular septal defect (61,3, 23.4%). Average peak VO2 (pVO2) was 22.3±8.1ml/kg/min, (66±22% of predicted). The VE/VCO2 slope was raised (>33) in 128 (49%) patients. Patients who were cyanotic at rest and/or desaturated during exercise had a significantly higher VE/VCO2 slope (40.3±15.9 vs. 33.6±9.0, p=0.0004) and lower pVO2 (20.7±8.0 vs. 24.3±7.7, p=0.0007). A total of 119 (46.1%) patients achieved target heart rate, while 36 (14.0%) patients were unable to achieve a heart rate of at least 60% predicted.

Over a median follow up of 3.0 [1.1–5.9] years, 36 (13.7%) patients died. Univariable predictors of mortality from CPET included pVO2, VE/VCO2 slope, heart rate reserve (HRR), anaerobic threshold, peak systolic blood pressure and exercise time (Figure). On bivariable analysis using pVO2 with each of the other exercise parameters, only peak systolic blood pressure remained in the model, even when adding age. In ccTGAs, peak VO2 was the only parameter remaining in the multivariable models. In ASR patients, HRR was stronger than all other parameters.

Conclusion

In this large cohort of patients with systemic RVs, older than existing reports in this area, peak VO2, peak systolic BP and HRR appear to be stongly related to mortality. These findings reflect the underlying physiology and consequences of previous surgery and should be used in clinical practice to risk stratify patients.

Kaplan-Meier curves

Funding Acknowledgement

Type of funding source: None

Peak oxygen uptake on cardio pulmonary exercise testing predicts mortality in adult Fontan patients

Introduction

The Fontan operation has revolutionized the outcome of patients with univentricular hearts. However, long-term morbidity and mortality remain high and exercise intolerance in common in this population. Previous studies have failed to demonstrate a clear relation between exercise capacity, expressed as peak oxygen consumption (pVO2), and the risk of death in contrast with other congenital and non-congenital cohorts.

Aims

To investigate the correlates of pVO2 in the Fontan population and its relation to mortality.

Methods

Data were collected retrospectively on consecutive patients with a Fontan circulation who underwent a cardiopulmonary exercise test (CPET) between 2005–2019. Clinical and exercise data were collected at the time of CPET and patients were followed thereafter. Cox regression analysis was used to assess the association between exercise parameters and mortality. Different methods of estimating predicted pVO2 were compared in their impact on the prognostic value of pVO2.

Results

A total of 152 patients were included. Mean age at CPET was 28.9±9.3 years and 74 (48.7%) were female. The majority of patients had a total cavo-pulmonary connection (TCPC; 53.3%) followed by atrio-pulmonary (2.1%) and other Fontan variants 4.6%. The majority of patients reported no limitation on physical activity [AC1] (NYHA class I, 91, 62.3%). Baseline oxygen saturation was 93±5% and 26 (17.6%) patients had a persistent fenestration. On exercise, pVO2 was 21.9±7.4ml/min and was significantly reduced in the majority of asymptomatic patients (56.1±17.4% predicted according to the Wasserman/Hansen (WH) formula). The VE/VCO2 slope was raised (>33) in 92 (60.9%) patients. A total of 88 (58.7%) patients had an impaired heart rate reserve, and were unable to achieve a heart rate of at least 70% predicted.

Over a median follow-up of 4.6 [2.5–8.9] years, 25 (16.4%) patients died. pVO2 expressed as ml/min was the only exercise parameter related to mortality in this cohort (HR 0.93, 95% CI: 0.87–0.99, p=0.03).pVO2 was even more strongly related to mortality when expressed as percentage of predicted using the WH formula (HR 0.76, 95% CI: 0.59–0.98, p=0.03), but not the Jones formula for predicted pVO2 (HR 0.83, 95% CI: 0.67–1.02, p=0.08). Additional predictors of outcome included NYHA class (no asymptomatic patients died), use of loop diuretics and a non-TCPC circulation, but not age or sex were not (Figure 1). On multivariable analysis, percent predicted pVO2 (WH) remained a predictor of outcome (HR per 10 unit increase 0.65, 95% CI: 0.46–0.93, p=0.017) with NYHA class and diuretic treatment, and with the type of Fontan operation.

Conclusion

A clear relation between pVO2 and mortality could be demonstrated in this Fontan population by using unadjusted pVO2, or appropriate estimates of predicted pVO2. CPET can thus be used for the risk stratification of Fontan patients, providing that care is taken in the way that pVO2 is reported and interpreted.

Figure 1

Funding Acknowledgement

Type of funding source: None

Long-term outcomes amongst adults with anatomic repair for transposition of the great arteries: not as perfect as we would have hoped?

Background

The arterial switch operation (ASO) has replaced atrial switch procedures for D-transposition of the great arteries (D-TGA), with 90% of patients now reaching adulthood. However, patients may have residual lesions and/or sequelae, some of which may remain unrecognized, necessitating lifelong specialist surveillance. We examined the cardiac outcomes of a large number of contemporary ASO patients under tertiary adult congenital heart disease (ACHD) care.

Methods

We examined late major adverse cardiovascular events (MACE) in adult TGA patients (>16 years) who underwent an ASO between 1981 and 2003 and continued their follow-up in 2 tertiary ACHD centers. MACE were defined as death, re-intervention, myocardial ischemia, arrhythmia, stroke/TIA, infective endocarditis and heart failure.

Results

Overall, 199 patients (66% male, mean age 27±5 years) were followed in adult life for a median of 10 years [IQR 7–15] and were included in this study. Overall survival during this period was 99.5% (95% confidence interval [CI]: 94.4%-99.8%). Sixty-two (31.2%) patients experience MACE, including 52 reinterventions. MACE and reintervention-free survival at 20, 30 and 35 years were 87.6%, 58.6%, 50.6% and 89.5%, 69.1, 61%, respectively. Atrial arrhythmia was the most frequent cardiac event with an incidence of 5.5 cases per 1000 patient-years, whereas incidence of ventricular tachycardia and sudden cardiac death was 1.8‰ and 0.9‰ patient-years, respectively. Coronary artery disease was diagnosed in 6 (3%) patients, of whom 4 had symptoms, 1 had ST depression on ECG at rest and 3 had abnormal wall motion on echocardiography. The most frequent indication for reoperation was right ventricular outflow tract obstruction (n=35/52, 63.7%), whereas left ventricular outflow tract (LVOT) re-interventions rate increased significantly during adulthood compared to childhood from 1% to 5%, p=0.03 (Figure 1). On multivariate analysis, history of cardiac complications during infancy (HR 2.3, 95% CI:1.3–4.0, p<0.01) and uncommon coronary patterns (HR for type A versus B/C/D/E 0.47, 95% CI:0.26–0.83, p<0.01) were independent predictors of MACE in adulthood. At the latest follow-up, 90.9% of patients were functional class I, left ventricular ejection fraction was 59.6±6.5% and peak oxygen uptake 71.1±24.9% predicted. At least moderate neoaortic regurgitation and aortic dilatation (≥40mm) were present in 8.0% and 35.2%, respectively, with more than mild pulmonary stenosis in 19.6%.

Conclusion

Adult patients with ASO for TGA have a low late mortality. However, MACE are common requiring reintervention, particularly for RVOT obstruction and neo-aortic valve dysfunction, the latter with rising rates during adulthood. Patients with cardiovascular complications during childhood are at the highest risk for MACE. All patients merit life-long tertiary care.

Figure 1

Funding Acknowledgement

Type of funding source: Public hospital(s). Main funding source(s): Assistance Publique des Hôpitaux de Paris

P1798Assessing attitudes and knowledge of infective endocarditis in adult survivors of congenital heart disease

Background

Adults with congenital heart disease (ACHD) have an increased risk of infective endocarditis (IE), which is associated with significant morbidity and mortality. This risk is further compounded by patient-related factors such as education and awareness of IE. The onus of patient education falls on both patient and physician, and is paramount to successful outcomes. Our study sought to evaluate patients' understanding of the risks, preventative measures and symptoms of IE, and to identify high-risk ACHD patients who would benefit from targeted education.

Methods

A cross-sectional study was conducted using a pre-tested questionnaire to assess knowledge of and attitudes towards IE. Patients attending the outpatient department of a tertiary referral centre completed the questionnaires independently. Baseline demographics and clinical data were collected from electronic patient records.

Results

132 questionnaires were completed (median age 38 years, 50% male). 106 patients (80%) had previous surgical or percutaneous interventions and 7 patients (5%) had suffered with infective endocarditis in the past. 37% were able to accurately define IE. Out of a range of symptoms, most patients chose temperature (47%) and tiredness (39%) as classical symptoms of IE, however none correctly identified all listed symptoms as potential signs of IE. The majority of patients knew tooth abscess (58%) and body piercings (50%) were risk factors for IE. A fifth of patients (20%) were failing to have annual dental check-ups. 22% thought that IE would only require a few days stay as an inpatient and only 20% of patients were aware of the requirement for prolonged antibiotic treatment and the majority (63%) were unaware of the potential need for open heart surgery. 1 in 4 patients could recall having received information regarding IE. A third of patients reported that they would have made lifestyle changes had they known that IE required prolonged intravenous antibiotic treatment and could result in open heart surgery and death.

Discussion

Our study highlights key issues in the management of ACHD. Moving forward with the continuously growing population of patients we need to focus on the multi-disciplinary approach including specialist clinical nurses and increasing awareness online and through meetings and patient days as well as the importance of transition services as paediatric patients move across to adult specialists. General physcians will also encounter ACHD, therefore it is important to ensure awareness is widespread in the form online platforms and leaflets. We must also acknowledge the impact of guidelines and ensure there is still a significant focus on IE within them. To conclude, despite the significant morbidity and mortality associated with IE in ACHD, patient awareness of symptoms, risk factors and consequences is limited. Promotion of IE awareness is a cost-effective intervention, which can reduce the incidence and complications of IE.

P3654Location of the coronary origins in transposition patients following anatomical repair: Implications for invasive coronary angiography and intervention

Background

Surgical repair of transposition of the great arteries (TGA) is most commonly via the arterial switch operation (ASO). This involves translocation of the aorta and pulmonary trunk, typically with anastomosis of the branch pulmonary arteries anteriorly (LeCompte manoeuvre) and re-implantation of the coronary arteries onto the posterior neo-aorta. As such, the position of the coronary ostia may differ from their expected locations.

Purpose

To use ECG-gated CT angiography to describe the anatomic position of coronary ostia in post-switch TGA patients guiding potential catheter interventions in this population.

Methods

All post ASO patients who underwent CT imaging between 2008–2018 were identified. Patients with complex anatomy such as double outlet right ventricle were excluded. The positions of the coronary ostia were measured in degrees from vertical on a double-oblique reconstruction in the aortic valve plane. Ostium positions were compared to those of patients with no congenital heart disease via Watson's two-sample test of homogeneity for circular data. Angular dispersion was compared between groups via the Wallraff test. P<0.05 indicated statistical significance.

Results

Of 206 adult patients with TGA and ASO followed in our adult congenital heart disease centre, 38 (18.4%) had CT imaging available for analysis during the study period (mean age 24±6.8, 75% male).

The control group consisted of 15 patients investigated for chest pain (mean age 54±15.1, 73% male). In the control group, the right and left coronary ostia arose at a mean angle of −19 and +125 degrees from vertical (figure 1a). This was significantly different to the mean ASO coronary ostia clustered at mean angles of −70 and +29 degrees from vertical (Watson p<0.001) (figure 1b, with stenosis at the left coronary anastomosis).

There was no significant difference in spread of left ostia (Rho 0.9 vs 0.99, p=0.12), but right ostia were significantly more variable in ASO patients than controls (0.71 vs 0.96, p=0.003).

Figure 1

Conclusions

Coronary ostial positions in the neo-aorta of post-ASO patients differ significantly from those of normal controls, with considerable variability, especially in right coronary position. CT can demonstrate coronary ostia in 3D space and derive appropriate tube angles to guide catheterisation in post-operative congenital cardiac patients, optimise catheter selection, reduce catheterisation tome, radiation and contrast dose.

P4693Contemporary survival of adults with a systemic right ventricle

Background

In complete transposition of the great arteries (TGA) with previous atrial switch operation and congenitally corrected transposition of the great arteries (ccTGA), the morphological right ventricle and its tricuspid valve support the systemic circulation. This results in late complications, including systemic right ventricle (sRV) failure, systemic atrioventricular valve regurgitation, and rhythm disturbances, affecting long-term outcome. We aimed to describe contemporary survival and determine predictive factors of death in an adult cohort with a sRV.

Methods and results

All adult patients (>16 years of age) with a sRV under active follow-up between January 2000 and December 2018 in our tertiary center were included. Demographic and clinical details were obtained from records. Baseline clinical status, transthoracic echocardiography, cardiopulmonary exercise testing and BNP were taken at the earliest available assessment during the study period.

Two hundred thirty-six patients, 141 with TGA/ 95 ccTGA, were included (mean age at baseline 31±12 years, 45% female sex). Over a median follow-up of 10.2 years IQR [5.6–14.9], 27 patients died, and 2 patients underwent heart transplantation. Cause of death was heart failure in 13 patients, sudden cardiac death in 2, and unspecified in 12. Survival at 5, 10 and 15 years of follow-up was 97.5%, 90.0% and 81.0%, respectively (Figure 1A).

On univariate Cox regression analysis, history of atrial arrhythmia, heart failure, and pulmonary arterial hypertension, baseline NYHA functional class ≥2, BNP≥120ng/L, peak VO2 and moderate/severe sRV function were predictive of death/heart transplantation. In contrast, previous permanent pacing, moderate or severe pulmonary stenosis, and use of beta-blockers were not associated with an increased risk of death. On multivariate analysis, NYHA ≥2 (HR=5.3 95% CI [1.1–25.6], p=0.03) and peak VO2 (HR=0.95 95% CI [0.91–0.99], p=0.01) were the strongest independent predictors of death. Patients with NYHA class≥2 and/or a pVO2<60% of predicted had a 3.6-fold higher risk of death compared to the remainder, even after adjustment for cardiac treatment at baseline (p=0.03, Figure 1B)

Figure 1. (A) Long term survival with 95% confidence intervals. (B) Survival according to the presence of symptoms (NYHA functional class ≥2) and/or a peak VO2 <60% predicted.

Conclusions

Mortality remains considerable in a contemporary cohort of adults with a sRV. Heart failure appears to be the leading cause of death, whereas only a few patients benefit from transplantation. Symptomatic patients with moderate or severe reduction in peak VO2 are at increased risk of adverse outcome in this setting and merit a more proactive approach and management.

Acknowledgement/Funding

Fundaciόn Alfonso Martín Escudero

78Predictors of perioperative mortality in adults with congenital heart disease (ACHD): utility of the EuroSCORE and creation of an ACHD-specific score

Introduction

Adult patients with congenital heart disease (ACHD) are a heterogeneous population and a variety of procedures are performed in ACHD centers, which differ significantly from those performed in the general adult population. Therefore, ACHD patients have not been included in the development of risk stratification models, such as the EuroSCORE. We assessed the utility of the components of the EuroSCORE in predicting in-hospital mortality around surgery in a large cohort of ACHD patients and tested a modified risk score for the ACHD population.

Methods

Data were collected retrospectively on all consecutive patients >16 years who underwent congenital heart disease surgery in a large tertiary center in 2015–18. Preoperative characteristics and perioperative outcomes were collected from clinical records and databases. Wilcoxon rank sum test, Fisher's test and Logistic regression analysis were used to identify predictors of in-hospital death. Variables significant on univariate linear regression were used to create a risk score for each patient, either attributing 1 point for each risk factor (unweighted model), or weighing this by its log(Odds ratio) in the logistic regression model (weighted score). Receive operator characteristic (ROC) analysis with calculation of the areas under the curve (AUC) was used to assess the performance of each scoring system in predicting in-hospital mortality.

Results

A total of 476 operations occurred in 459 patients who underwent cardiac surgery during the study period. Age at surgery was 35.9±14.7 years, 258 (56.2%) were male, 231 (51.3%) patients had a previous sternotomy. There were 19 (4.1%) in-hospital deaths. Certain components of EuroSCORE were very rarely observed in our ACHD patients and were not included in the analysis. Of components of the EuroSCORE, female sex (OR 3.79, 95% CI: 1.42–11.89, p=0.01), functional NYHA class>2 (OR 7.65, 95% CI: 2.35–29.26, p=0.001), left ventricle dysfunction (OR 3.14, 95% CI: 1.22–8.01, p=0.02), previous surgery (OR 5.33, 95% CI: 1.41–34.68, p=0.03), emergency or urgent surgery (OR 7.96, 95% CI: 3.1–21.99, p<0.0001), renal dysfunction (MDRD GFR<60 OR 6.56, 95% CI: 1.73–20.52, p=0.002), endocarditis (OR 7.71, 95% CI: 1.6–28.85, p=0.004), and a critical preoperative state (OR 28.65, 95% CI: 5.11–147.93, p<0.0001) were predictive of an adverse perioperative outcome. Moreover, the number of previous sternotomies was predictive of mortality (OR 2.45, 95% CI: 1.58–3.85, p<0.0001). Both the unweighted (AUC 0.78, 95% CI: 70.6–85.3), but especially the weighted risk score (AUC 0.82, 95% CI: 74.8–89) had an optimal discriminative power (Figure).

Conclusions

While several components of the EuroSCORE are relevant to ACHD patients, an ACHD-specific scoring system for predicting perioperative mortality is needed. In this analysis, we propose a simplified risk score for ACHD patients undergoing surgery, which performs well in this population.

4971Blood viscosity and its relevance to the diagnosis and management of pulmonary hypertension: a new elephant in the cathlab

Background

Pulmonary vascular resistance (PVR) is an essential parameter assessed during cardiac catheterization. It is used to confirm pulmonary vascular disease, to assess response to targeted pulmonary hypertension (PH) therapy and to determine the possibility of surgery, such as closure of intra-cardiac shunt or transplantation. While PVR is believed to mainly reflect the properties of the pulmonary vasculature, it is also related to blood viscosity (BV).

Objectives

We aimed to assess the relationship between measured (mPVR) and viscosity-corrected PVR (cPVR) and its impact on clinical decision-making.

Methods

We assessed consecutive PH patients undergoing cardiac catheterization. BV was assessed using the Hutton method.

Results

We included 465 patients (56.6% female, median age 63y). The difference between mPVR and cPVR was highest in patients with abnormal Hb levels (anemic patients: 5.6 [3.4–8.0] vs 7.8Wood Units (WU) [5.1–11.9], P<0.001; patients with raised Hb: 10.8 [6.9–15.4] vs. 7.6WU [4.6–10.8], P<0.001, respectively). Overall, 33.3% patients had a clinically significant (>2.0WU) difference between mPVR and cPVR, and this was more pronounced in those with anemia (52.9%) or raised Hb (77.6%). In patients in the upper quartile for this difference, mPVR and cPVR differed by 4.0WU [3.4–5.2].

Adjustment of PVR required

Conclusions

We report, herewith, a clinically significant difference between mPVR and cPVR in a third of contemporary patients assessed for PH. This difference is most pronounced in patients with anemia, in whom mPVR significantly underestimates PVR, whereas in most patients with raised Hb, mPVR overestimates it. Our data suggest that routine adjustment for BV is necessary.

P3653Aortic regurgitation in the young - Is it time to rethink the guidelines?

Background

Establishing surgical indication for aortic valve replacement or repair (AVR) in the setting of severe aortic regurgitation (AR) can be challenging in young patients. Current guidelines state patients should be operated based on symptoms, presence of left ventricular (LV) dysfunction (Ejection Fraction, EF ≤50%) or severely LV dilatation (LV end diastolic diameter, LVEDD ≥70mm or LV end systolic diameter, LVESD ≥50mm) 1.

Purpose

Our goal was to study the change of the LV size and function in a cohort of young adults with severe AR after surgery and relate this to pre-operative ventricular characteristics.

Methods

We reviewed all patients who underwent AVR in our centre between 2013 and 2018. The echocardiographic data was collected prior to, pre discharge and at 6–12 months after surgery. A ROC analysis was used to determinate the discriminative power of baseline LV diameters in predicting normalization of LV size pre discharge. Normal values were considered as per the guidelines3.

Results

A total of 75 adult patients were included: mean age 25±10.5 years, 64% male. The majority (61%) had a bicuspid valve, 17% an autograft (previous Ross procedure), 10% developed AR after a VSD was closed, 6% had an arterial switch procedure, 3% a truncal valve and 3% Tetralogy of Fallot. 10% went for a Ross procedure, 60% received a bioprosthetic and 30% a mechanical aortic valve. The majority (61%) were completely asymptomatic.

The vast majority (88%) were operated with LVEDD ≤70mm (mean 60±6.9mm), 84% had a LVESD ≤50mm and 80% had an LVEF >50%. A significant reduction in LVEDD occurred within a few days from surgery: mean reduction 9.2±6.2mm, p<0.0001). No further significant reduction was observed in the follow up (average change −1.12±7.1mm, p=0.24). LVESD dropped by 3.4±7.3mm (p<0.0001) immediately post-surgery and a further 3.32±9.6mm (p=0.12) after. Immediately post surgery there was a significant reduction in the LVEF (6.9±9.6%, p<0.0001), which however improved significantly (6% ±9.8, p<0.001) on the follow up. As a result, there was no significant change in LVEF from baseline to the latest follow up (change ±1%, p=0.57).

On ROC analysis the baseline LVEDD and LVESD were excellent predictors of lack of normalization of LV size post surgery (AUC=0.82, 95% CI: 0.70–0.94 and AUC=0.79, 95% CI 0.66–0.92, respectively).

Sensitivity and specificity for normalization of LVEDD were 87% and 73%, with a preoperative LVEDDD cut-off value of ≥61mm. A cut off point of ≥42mm on the LVESD achieved a sensitivity of 83% and specificity of 65%.

Conclusions

In our practice we tend to operate on young patients with severe AR earlier than stated in the guidelines. Our data supports this approach, demonstrating that patients with significantly increased LV diameters prior to surgery do not tend to remodel in the first postoperative echo. Despite operating early, patients with LV EF <55% are less likely to normalize the LV size in the post operative period.

A new modality of treatment for non-united fracture of the humerus in a patient with osteopetrosis: a case report

Introduction

Osteopetrosis introduces technical limitations to the traditional treatment of fracture management that may be minimised with specific pre-operative planning. Extreme care and caution are required when drilling, reaming, or inserting implants in patients with osteopetrosis. Caution must be exercised throughout the postoperative course when these patients are at greatest risk for device failure or further injury.

Case presentation

We present our experience of treating such a fracture where a patient presented with a non-united fracture of the humerus. The bone was already osteoporotic. We successfully used a new technique which has not been described in the literature before. This included the use of a high-speed drill to prepare the bone for screw fixation. Bone healing was augmented with bone morphogenic protein.

Conclusion

This technique can give invaluable experience to surgeons who are involved in treating these types of fracture.

Vascularised bone grafting in the management of scaphoid non-union - a review of 34 cases

We reviewed the outcomes of 34 patients who had undergone vascularised bone grafting for a chronic scaphoid non-union. Mean age was 27 years (range 16-46 years). The dominant hand was involved in 17 cases. Eleven patients were smokers. In 18 cases the fracture involved the proximal and in 16 cases the middle third of the scaphoid. In 26 patients the proximal scaphoid fragment was deemed avascular. Sixteen patients had previously undergone scaphoid fixation and non-vascularised bone grafting. At a follow-up of 1 to 3 years (mean 1.6 years), 15 of the 34 scaphoid non-unions had united. Injury to the dominant hand and duration of the non-union significantly increased the risk of failure. Persistent non-union was more common in proximal third fractures and in the presence of an avascular proximal pole but these findings did not reach statistical significance.

Acute rhabdomyolysis following acute compartment syndrome of upper arm

Compartment syndromes of the upper arm are rare, and patients presenting with suspected problem in this region may not have physical signs as obvious as those presenting with symptoms of forearm and lower extremity. This case report describes the aetiology, diagnosis and the management of compartment syndrome that presented in upper arm.

Medium-term results with the Press Fit Condylar (PFC) Sigma knee prosthesis the Wrightington experience

The PFC Sigma total knee was introduced in 1997, incorporating a number of design changes. We report the mid-term results of a consecutive series of PFC Sigma knee arthroplasties performed between November 1997 and December 1998. Out of a total of 156 patients (166 knees), 5 patients (5 knees) were lost to follow-up and 6 patients (6 knees) died of unrelated causes. This left 145 patients (155 knees), 90 female and 55 male, with a mean age of 70 years (range, 53-88) and an average follow-up of 90 months (range, 84-96). Posterior cruciate retaining components were used in 136 knees (88%) and posterior-stabilized in 19 (12%). The patella was resurfaced in 74 (48%) knees. Follow-up was at 3, 6 and 12 months, then yearly. Preoperative American Knee Society and Oxford scores were compared with follow-up scores. The Knee Society radiological score was used for radiographic assessment. One knee (0.6%) was revised due to aseptic loosening. One knee (0.6%) had superficial wound infection, which settled with oral antibiotics. Two knees became deeply infected. Of these, one resolved following early debridement, the other developed chronic infection. Using revision for any reason as the end-point our cumulative success rate was 99.4%. The mean preoperative Knee score improved from 45 (30-65) to 84 (45-92), Functional score from 38 (25-55) to 73 (50-95) and Oxford score from 43 (33-52) to 17 (14-29). Radiographic review showed radiolucent lines in 54 (35%) tibial and 17 (11%) femoral components. The Radiological Knee Society score was less than 4 in all except one tibia where the score was 7. Our study shows excellent clinical results with the PFC Sigma total knee replacement after almost eight years follow-up.

The microbiology of infected hip arthroplasty

Infection following joint replacement surgery although rare presents a challenging problem. Bacterial resistance to antibiotics is an emerging problem. We analysed the microbiology of 337 single-stage revisions for deep infection. Coagulase negative staphylococcus was found to be the predominant organism, although staphylococcus aureus is gaining importance. Gentamicin only provides cover for 64.1% of organisms. Resistance to this commonly used antibiotic prophylaxis is escalating. Fusidic acid and erythromycin provide improved cover. We would suggest on a microbiological basis that these antibiotics be considered for addition to acrylic bone cement. This will provide local antibiotic delivery when performing a revision for deep infection.

Importin beta1 mediates the glucose-stimulated nuclear import of pancreatic and duodenal homeobox-1 in pancreatic islet beta-cells (MIN6)

The transcription factor PDX-1 (pancreatic and duodenal homeobox-1) is essential for pancreatic development and the maintainence of expression of islet beta-cell-specific genes. In an previous study [Rafiq, Kennedy and Rutter (1998) J. Biol. Chem. 273, 23241-23247] we demonstrated that PDX-1 may be activated at elevated glucose concentrations by translocation from undefined binding sites in the cytosol and nuclear membrane into the nucleoplasm. In the present study, we show that PDX-1 interacts directly and specifically in vitro with the nuclear import receptor family member, importin beta1, and that this interaction is mediated by the PDX-1 homeodomain (amino acids 146-206). Demonstrating the functional importance of the PDX-1-importin beta1 interaction, microinjection of MIN6 beta-cells with anti-(importin beta1) antibodies blocked both the nuclear translocation of PDX-1, and the activation by glucose (30 mM versus 3 mM) of the pre-proinsulin promoter. However, treatment with extracts from pancreatic islets incubated at either low or high glucose concentrations had no impact on the ability of PDX-1 to interact with importin beta1 in vitro. Furthermore, importin beta1 also interacted with SREBP1c (sterol-regulatory-element-binding protein 1c) in vitro, and microinjection of importin beta1 antibodies blocked the activation by glucose of SREBP1c target genes. Since the subcellular distribution of SREBP1c is unaffected by glucose, these findings suggest that a redistribution of importin beta1 is unlikely to explain the glucose-stimulated nuclear uptake of PDX-1. Instead, we conclude that the uptake of PDX-1 into the nucleoplasm, as glucose concentrations increase, may be mediated by release of the factor both from sites of retention in the cytosol and from non-productive complexes with importin beta1 at the nuclear membrane.

Glucose-stimulated preproinsulin gene expression and nuclear trans-location of pancreatic duodenum homeobox-1 require activation of phosphatidylinositol 3-kinase but not p38 MAPK/SAPK2

Exposure of islet beta-cells to elevated glucose concentrations (30 versus 3 mm) prompts enhanced preproinsulin (PPI) gene transcription and the trans-location to the nucleoplasm of pancreatic duodenum homeobox-1 (PDX-1; Rafiq, I., Kennedy, H., and Rutter, G. A. (1998) J. Biol. Chem. 273, 23241-23247). Here, we show that in MIN6 beta-cells, over-expression of p110.CAAX, a constitutively active form of phosphatidylinositol 3-kinase (PI3K) mimicked the activatory effects of glucose on PPI promoter activity, whereas Deltap85, a dominant negative form of the p85 subunit lacking the p110-binding domain, and the PI3K inhibitor LY 294002, blocked these effects. Similarly, glucose-stimulated nuclear trans-location of endogenous PDX-1 was blocked by Deltap85 expression, and wortmannin or LY 294002 blocked the trans-location from the nuclear membrane to the nucleoplasm of epitope-tagged PDX-1.c-myc. By contrast, SB 203580, an inhibitor of stress-activated protein kinase-2 (SAPK2)/p38 MAP kinase, had no effect on any of the above parameters, and PPI promoter activity and PDX-1.c-myc localization were unaffected by over-expression of the upstream kinase MKK6 (MAP kinase kinase-6) or wild-type p38/SAPK2, respectively. Furthermore, no change in the activity of extracted p38/SAPK2 could be detected after incubation of cells at either 3 or 30 mm glucose. These data suggest that stimulation of PI3K is necessary and sufficient for the effects of glucose on PPI gene transcription, acting via a downstream signaling pathway that does not involve p38/SAPK2.

Glucose enhances insulin promoter activity in MIN6 beta-cells independently of changes in intracellular Ca2+ concentration and insulin secretion

Recent studies have suggested that glucose may activate insulin gene transcription through increases in intracellular Ca(2+) concentration, possibly acting via the release of stored insulin. We have investigated this question by dynamic photon-counting imaging of insulin- and c-fos-promoter-firefly luciferase reporter construct activity. Normalized to constitutive viral promoter activity, insulin promoter activity in MIN6 beta-cells was increased 1.6-fold after incubation at 30 mM compared with 3 mM glucose, but was unaltered at either glucose concentration by the presence of insulin (100 nM) or the Ca(2+) channel inhibitor, verapamil (100 microM). Increases in intracellular [Ca(2+)] achieved by plasma membrane depolarization with KCl failed to enhance either insulin or c-fos promoter activity in MIN6 cells, but increased c-fos promoter activity 5-fold in AtT20 cells. Together, these results demonstrate that glucose can exert a direct effect on insulin promoter activity in islet beta-cells, via a signalling pathway which does not require increases in intracellular [Ca(2+)] nor insulin release and insulin receptor activation.

Glucose-dependent translocation of insulin promoter factor-1 (IPF-1) between the nuclear periphery and the nucleoplasm of single MIN6 beta-cells

Using laser-scanning confocal microscopy, we have monitored glucose-induced changes in the subcellular localization of insulin promoter factor-1 (IPF-1) labeled with a c-myc epitope tag. This construct trans-activated the insulin promoter in single living MIN6-beta-cells as assessed by luciferase-based promoter analysis. IPF-1.c-myc expression also enhanced the response of the insulin promoter to elevations in extracellular glucose concentration. In the majority (148/235, 63%) of cells maintained at low (3 mM) extracellular glucose concentration, IPF-1.c-myc immunoreactivity was confined to the nuclear periphery. Incubation of cells at stimulatory (30 mM) glucose concentrations caused a rapid redistribution of the chimera to the nucleoplasm (775/958, 81% of cells). By contrast, the irrelevant transcription factor c-Fos, tagged with either c-myc or as a chimera with luciferase, was localized exclusively to the nucleoplasm irrespective of the glucose concentration. Furthermore, IPF-1 extended with the bulky (27 kDa) enhanced green fluorescent protein (EGFP) group was confined largely to the nucleoplasm at all glucose concentrations tested and did not support trans-activation of the insulin promoter by glucose. Movement of endogenous IPF-1 from the nuclear periphery to the nucleoplasm may therefore increase the trans-activational capacity of this factor in native beta-cells exposed to high extracellular glucose concentrations.

Upstream stimulatory factor-2 (USF2) activity is required for glucose stimulation of L-pyruvate kinase promoter activity in single living islet beta-cells

Elevated glucose concentrations stimulate L-pyruvate kinase (L-PK) gene transcription in liver and islet beta-cells. A glucose response element termed the L4 box (two noncanonical E-boxes located -165 and -154 base pairs upstream of the transcriptional start point) has previously been defined within the proximal promoter region of the gene. However, the identity of the transacting factor(s) which binds to this site remains unclear. We have used photon counting digital imaging of firefly luciferase activity to monitor promoter activity continuously in single living islet beta and derived INS-1 cells, and to analyze the molecular basis of the regulation by glucose. L-PK promoter activity, normalized to cytomegalovirus promoter activity using the distinct Renilla reniformis luciferase, was >/=6-fold higher in cells cultured at 16 mM glucose or above compared with cells cultured at 3 mM glucose. Microinjection of antibodies against the ubiquitous transcription factor USF2 inhibited L-PK promoter activity in beta- and INS-1 cells incubated at 30 mM glucose by 71-87%. Anti-USF2 antibodies had a much smaller effect on promoter activity in INS-1 cells cultured at 3 mM glucose, and on the activity of a modified promoter construct lacking an L4 box. These data support the view that glucose enhances L-PK gene transcription in beta-cells by modifying the transactivational capacity of USF2 bound to the upstream L4 box.