NOAC in adult congenital heart disease patients: a single-center experience

Background

Adult Congenital Heart Disease (ACHD) patients at increased risk for thromboembolic events are often treated with oral anticoagulation. While vitamin-K antagonists have been the agent of choice for decades, the use of non-vitamin K oral anticoagulants (NOAC) is increasing. We aimed to assess the safety and effectiveness of NOAC in ACHD patients at our centre.

Methods

This is a single-centre study enrolling all patients with ACHD treated with a NOAC from inception to November 2021. Data was collected using a standardized questionnaire applied to all patients by means of a telephone visit, in parallel with a detailed retrospective chart review. The endpoints of interest included thromboembolic and haemorrhagic events, defined as per the standardized International Society on Thrombosis and Haemostasis (ISTH) scale.

Results

Overall, 36 ACHD patients were enrolled [mean age 53±15 years; female sex – 66.7%; previous stroke – 33.3%; median HAS-BLED and CHA2DS2-VASc score – 1 (1–2) and 3 (2–5), respectively], predominantly with moderate or complex congenital defects (52.7%), of whom 14, 8, 8 and 4 were treated with rivaroxaban, apixaban, edoxaban and dabigatran, respectively. Two-thirds had their first NOAC prescription in the latest 3 years (Figure 1). The most common indication for anticoagulation was atrial fibrillation or flutter (77.8%). Over a median time of 36 (18–63) months on NOAC treatment, there were no patients with thromboembolic events, whilst 13 (36.1%) had a haemorrhagic event – annualized event rate of 12.0 (6.9–24.1%). All bleeding events were minor, most often self-limited gingival haemorrhage or epistaxis (n=7) or menorrhagia (n=3). Nasal cautery was needed to treat recurrent epistaxis in 3 patients, whilst 3 other required oral iron supplementation. The strongest predictor of any haemorrhage was a prior cardiovascular hospitalization (HR 3.88; p=0.027).

Conclusions

The use of NOAC in ACHD patients has been increasing in our centre, with encouraging results. The present findings suggest that NOAC are safe and may be effective for thromboembolic event prevention in heterogeneous forms of ACHD.

Funding Acknowledgement

Type of funding sources: None.

Cardiopulmonary exercise testing in Fontan patients: unmasking the secret of Super-Fontans

Background

Exercise capacity is usually reduced in Fontan patients, however there is a subset of patients who have normal exercise capacity and better outcomes, the “Super-Fontans”. The aim of this study was to characterize a cohort of Fontan patients undergoing cardiopulmonary exercise testing (CPET) and identify predictors of better functional capacity.

Methods

Single center retrospective analysis of consecutive Fontan patients aged >10 years old who underwent CPET, between March 2018 and May 2021.

Peak respiratory exchange ratio1.05 defined maximal CPET. Peak VO2 (pVO2) as a percentage of its predicted value was used as reference value to stratify patients in tertiles.

Patients in 3rd tertile, with a percentage predicted pVO2 superior to 75%, were considered good-performers.

Blood tests and transthoracic echocardiogram (TTE) were performed on the same day. Additional data were collected from electronic charts.

Results

In total, 49 patients were included (mean age 19±7 years old, 67% male) with intra or extracardiac conduit implanted in mean 12±7 years prior to the CPET.

The most common primary diagnoses were tricuspid/pulmonary atresia (43%), followed by unbalanced complete AV septal defect (14%) and double inlet left ventricle (14%). 12 patients had a systemic right ventricle. All, except 5 patients, had preserved systolic ventricular function and 37% had moderate to severe AV regurgitation.

The majority had normal hemoglobin levels (median 15.6 g/dL), hepatic enzymes (median total bilirubin 0.8 mg/dL), renal function (median creatinine 0.8 mg/dL) and low NT-proBNP (median 122 pg/mL).

All patients had maximal CPET, median %VO2 at VT1 was 57% of peak and mean pVO2 was 66±14% of the predicted. Most patients (69%) showed exercise limitation due to cardiovascular cause, followed by O2 desaturation, present in 22% of CPETs. The age of Fontan completion was not associated with functional capacity (p=0.6).

The good-performer group comprised 13 patients (27%), all in sinus rhythm, of which 10 were physically active. Compared with the remainder, this group had higher VO2 at VT1 (18.7 vs. 14.6, p=0.01) and VO2 at VT2 (25.9 vs. 22.1, p=0.02), both in mL/kg/min. Also, peak heart rate (% predicted) (90 vs. 81, p=0.03) was higher in this subgroup – fig.1. Conversely, differences on TTE parameters (GLS and AV valve regurgitation) and blood biomarkers were not statistically significant. On multivariable analysis, no single variable predicted better functional capacity.

Conclusion

In our Fontan cohort, most patients had reduced exercise capacity, largely due to cardiovascular dysfunction. However, “Super-Fontans” stood out as they had a higher anaerobic threshold illustrating their better physical condition. These findings highlight the role of regular physical activity in Fontan patients as a cornerstone for better functional capacity.

Funding Acknowledgement

Type of funding sources: None.

The peri-infarct gray zone of myocardial fibrosis is a better predictor of ventricular arrhythmias than dense core fibrosis in patients with previous myocardial infarction

Background

Current sudden cardiac death (SCD) risk stratification relies heavily on left ventricular ejection fraction (LVEF), but markers to refine risk assessment are needed. Dense core fibrosis (DCF) and peri-infarct “gray zone” of myocardial fibrosis (GZF) on late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) have been proposed as potential arrhythmogenic substrates. The aim of our study was to determine whether DCF and GZF could predict the occurrence of ventricular arrhythmias in patients with previous myocardial infarction.

Methods

We performed a single centre retrospective study enrolling consecutive patients with previous myocardial infarction undergoing CMR before implantable cardioverter-defibrillator (ICD) implantation. Areas of LGE were subdivided into “core” DCF and “peri-infarct” GZF zones based on signal intensity (>5 SD, and 2–5 SD above the mean of reference myocardium, respectively).

The primary endpoint was a composite of sudden arrhythmic death, appropriate ICD shock, ventricular fibrillation (VF), or sustained ventricular tachycardia (VT) as detected by the device.

Results

A total of 88 patients (median age 61 years [IQR 54–73], 84% male, median LVEF 30% [IQR 23–36%], 14% secondary prevention) were included. During a median follow-up of 23 months [IQR 9–38], 13 patients reached the primary endpoint (10 appropriate ICD shock, 2 sustained VT or VF, and 1 sudden arrhythmic death). Patients who attained the primary endpoint had similar DCF (30.4±14.7 g vs. 28.0±15.3 g; P=0.601) but a greater amount of GZF (18.1±9.6 g vs. 11.9±6.7 g; P=0.005). On univariate analysis, GZF was associated with the composite endpoint (HR: 1.09 per gram; 95% CI: 1.02–1.15; P=0.006), whereas DCF was not (HR: 1.01 per gram; 95% CI: 0.98–1.05; P=0.571). After adjustment for LVEF, GZF remained independently associated with the primary endpoint (adjusted HR: 1.06 per gram; 95% CI: 1.01–1.12; P=0.035). Decision tree analysis identified 11.9g of GZF as the best cut-off to predict life-threatening arrhythmic events. The primary endpoint occurred in 11 out of the 35 patients (31.4%) with GZF ≥11.9 g, but in only 2 of the 53 patients (3.8%) with GZF <11.9 g – Figure 1.

Conclusions

The extent of peri-infarct GZF seems to be a better predictor of ventricular arrhythmias than DCF. This parameter may be useful to identify a subgroup of patients with previous myocardial infarction at increased risk of life-threatening arrhythmic events.

Funding Acknowledgement

Type of funding sources: None.

Transthyretin amyloid cardiomyopathy: a 2-year single-centre experience

Background

Transthyretin Amyloid Cardiomyopathy (ATTR-CM) is an under-diagnosed condition often presenting with Heart Failure (HF). We aimed to assess a cohort of patients with ATTR-CM and HF, focusing on the centre strategies to identify new cases, prognosticate and tailor treatment.

Methods

We conducted an all-comers single-centre prospective registry of consecutive patients with HF due to ATTR-CM followed in our centre from November 2019 to 2021. As per site protocol, diagnosis is established according to the algorithm by Gilmore et al. and all patients are assessed in our HF outpatient clinic at least twice yearly with systematic electronic chart data collection. We evaluated disease-modifying treatment and compliance with the current European Guidelines and CHAD-STOP management. A summary of this program is presented in the central figure.

Results

Overall, 60 patients were included (mean age 83±7 years; 80% male). ATTR-CM was confirmed by the non-invasive algorithm in all but 8 patients, in whom endomyocardial biopsy was positive. Of those undergoing genetic testing (n=30), 7 (23%) presented with the hereditary form of ATTR-CM (4 Val50Met and 3 Val142Ile mutations). The initial presentation was most often HF (n=43), atrial fibrillation (n=9), or “incidental” myocardial uptake on 99mTc-HMDP bone scintigraphy (grade 2) performed for cancer staging (n=5). Beta-blockers were reduced or stopped in 40 (67%) patients, all of whom improved in NYHA class and/or NT-proBNP (>30% reduction) at 1–3 months. Tafamidis 61mg was started in 22 patients and 15 more currently await approval. Those initiated on or referred to tafamidis 61mg (n=37) had less severe HF, as per NYHA (class I-II – 94 vs. 50%, p=0.033) and performance status (e.g. Karnofsky score 80–100 – 79 vs. 21%, p=0.010). Of those already on tafamidis (n=22), NYHA class remained stable or improved in all but 1 patient. In the year following vs. preceding treatment there was 2 vs. 3 total HF hospitalizations. No drug-related severe adverse events were reported. Over a 2-year follow-up, 14 (23.3%) patients died, of whom 1 was on tafamidis (compassionate use for 19 months).

Conclusions

ATTR-CM recognition is improving in our dedicated rare disease program, possibly due to the implementation of several alert pathways. The identification of the disease at an earlier stage allows targeted treatment, compliant with the recommendations. Nonetheless, the rarity of this disease and the required expertise for its optimal management argues in favour of a national strategic plan based on referral centres for ATTR-CM.

Funding Acknowledgement

Type of funding sources: None.

CAD in kidney transplant recipients: a real-world assessment pre-ISCHEMIA-CKD

Background

The ISCHEMIA-CKD trial has shown that an initial invasive strategy, as compared to conservative treatment, did not reduce the risk of death and non-fatal myocardial infarction, nor did it improve quality-of-life in patients with advanced chronic kidney disease (CKD) and coronary artery disease (CAD) with moderate-to-severe ischemia. Similar findings were reported in patients with CKD enlisted for kidney transplantation (KT). We aimed to evaluate screening and treatment CAD strategies in patients who ultimately underwent KT at our center.

Methods

This is a single-center study of consecutive patients who received a KT from 2015 to 2020. Obstructive CAD was defined whenever one of the following criteria was met: lesion with a stenosis >70% (or >50%, if left main disease) or CAD requiring revascularization, as per the Heart Team discussion. CAD evaluation refers to non-invasive or invasive coronary angiography and/or stress testing, irrespective of clinical scenario.

Results

A total of 324 patients underwent KT [mean age 55±12 years; 65.1% male; CKD most often due to hypertensive or diabetic nephropathy and polycystic kidney disease – 41.8%; median time from renal replacement therapy (RRT) to KT – 60 (40–88) months]. A flow-chart summarizing CAD diagnosis over time is depicted in Figure 1. Overall, 119 (36.7%) patients had CAD evaluation prior to KT, of whom 21 underwent myocardial revascularization – 8, 12 and 1 patients with acute coronary syndrome (ACS), chronic coronary syndrome (CCS) and silent ischaemia, respectively. At a median time of 46 (25–66) months after KT, 36 (11.1%) more patients had CAD evaluation, of whom 8 underwent percutaneous myocardial revascularization – 6 and 2 for ACS and CCS, respectively. Those with obstructive CAD were older (64 vs 54 years-old; p<0.001), with a higher burden of cardiovascular (CV) risk factors (p<0.001) and more likely to have had a CV death (9.5 vs. 1.0%; p=0.025) or CV hospitalization (38.1 vs. 13.4%; p=0.007). CAD status (revascularized vs. non-revascularized) was not associated with improved major outcomes at follow-up. We found no strong predictors of CAD requiring revascularization post-KT, including time from RRT to KT. There were no patients with refractory angina, left main disease or reduced left ventricular ejection fraction (<40%) in need of myocardial revascularization over follow-up.

Conclusions

Obstructive CAD was uncommon in our cohort of patients who received a KT, most of whom with asymptomatic or mildly (monthly angina) symptomatic CCS or non-fatal ACS. These findings, together with the most recent evidence, may argue against routine CAD screening in all patients being enlisted for KT. Notwithstanding, randomized evidence is eagerly awaited to further guide treatment decisions in the post-ISCHEMIA-CKD era.

Funding Acknowledgement

Type of funding sources: None.

A cardiac magnetic resonance myocardial strain patterns analysis in left bundle branch block

Funding Acknowledgements

Type of funding sources: None.

Introduction

Recently, a classification with four types of septal longitudinal strain patterns was described using a speckle tracking based strain analysis in echocardiography suggesting pathophysiological continuum of LBBB-induced LV remodeling. Little data exist on feature tracking cardiac magnetic resonance (FT-CMR) in LBBB patients, and whether such patterns could be reproduced in CMR is not established yet.

Purpose

In this study, we aimed to: 1) Assess and reproduce the new strain patterns classification by CMR and 2) Evaluate its association with LV remodeling and myocardial scar in a LBBB cohort.

Methods

Single center registry which included LBBB patients with septal flash (SF) referred to CMR to assess the structural cause of LV dysfunction. LBBB was defined according to Strauss criteria as strict LBBB, non-strict LBBB or nonspecific LV conduction delay.

A semi-automated FT-CMR was used to quantify myocardial strain and detect the four septal longitudinal and radial strain patterns, according to the recent classification (LBBB-1 through LBBB-4) – Figure. Extent of SF was visually scored as mild, moderate, or prominent.

Results

A total of 115 patients were included (mean age 66±11 years; 57% men; 38% with ischemic heart disease). Median duration of QRS was 150± 26ms and majority of the patients (n=90, 78%) were classified as strict LBBB.

In longitudinal strain analyses LBBB-1 was observed in 23 (20%), LBBB-2 in 37 (32.1%), LBBB-3 in 25 (21.7%), and LBBB-4 in 30 (26%) patients. Patients at higher LBBB stages (longitudinal or radial pattern) had more prominent septal flash, greater LV volumes, lower LV ejection fraction and lower absolute global longitudinal, circumferential and radial strain values compared with patients in less advanced stages (p < 0.05 for all) - table.

There was no difference between patterns in clinical characteristics, ischemic etiology, QRS duration and time delay between septal and lateral LV wall.

Late gadolinium enhancement (LGE) was found in 63 patients (54.8%), with a septal location in 34 (29.6%) patients, lateral in 4 (3.5%) patients, septal and lateral in 11 (9.6%) patients. Furthermore, no difference was found for LGE presence, distribution or location between the four strain patterns.

Conclusions

Among patients with LBBB, our study found a good association between longitudinal and radial strain patterns with the degree of LV remodeling and LV dysfunction by FT-CMR analysis. Additionally, myocardial fibrosis didn’t seem to interfere with the staged LBBB classification.

The peri-infarct gray zone of myocardial fibrosis is a better predictor of ventricular arrhythmias than dense core fibrosis in patients with previous myocardial infarction

Funding Acknowledgements

Type of funding sources: None.

Background

Current sudden cardiac death (SCD) risk stratification relies heavily on left ventricular ejection fraction (LVEF), but markers to refine risk assessment are needed. Dense core fibrosis (DCF) and peri-infarct "gray zone" of myocardial fibrosis (GZF) on late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) have been proposed as potential arrhythmogenic substrates. The aim of our study was to determine whether DCF and GZF could predict the occurrence of ventricular arrhythmias in patients with previous myocardial infarction.

Methods

We performed a single centre retrospective study enrolling consecutive patients with previous myocardial infarction undergoing CMR before implantable cardioverter-defibrillator (ICD) implantation. Areas of LGE were subdivided into "core" DCF and "peri-infarct" GZF zones based on signal intensity (>5 SD, and 2-5 SD above the mean of reference myocardium, respectively).

The primary endpoint was a composite of sudden arrhythmic death, appropriate ICD shock, ventricular fibrillation (VF), or sustained ventricular tachycardia (VT) as detected by the device.

Results

A total of 88 patients (median age 61 years [IQR 54-73], 84% male, median LVEF 30% [IQR 23-36%], 14% secondary prevention) were included. During a median follow-up of 23 months [IQR 9-38], 13 patients reached the primary endpoint (10 appropriate ICD shock, 2 sustained VT or VF, and 1 sudden arrhythmic death). Patients who attained the primary endpoint had similar DCF (30.4g ± 14.7 vs. 28.0g ± 15.3; P = 0.601) but a greater amount of GZF (18.1g ± 9.6 vs. 11.9g ± 6.7; P = 0.005). On univariate analysis, GZF was associated with the composite endpoint (HR: 1.09 per gram; 95%CI: 1.02-1.15; P = 0.006), whereas DCF was not (HR: 1.01 per gram; 95%CI: 0.98-1.05; P = 0.571). After adjustment for LVEF, GZF remained independently associated with the primary endpoint (adjusted HR: 1.06 per gram; 95% CI: 1.01-1.12; P = 0.035). Decision tree analysis identified 11.9g of GZF as the best cut-off to predict life-threatening arrhythmic events. The primary endpoint occurred in 11 out of the 35 patients (31.4%) with GZF ≥11.9g, but in only 2 of the 53 patients (3.8%) with GZF <11.9g – Figure.

Conclusions

The extent of peri-infarct GZF seems to be a better predictor of ventricular arrhythmias than DCF. This parameter may be useful to identify a subgroup of patients with previous myocardial infarction at increased risk of life-threatening arrhythmic events.

Validation of a novel framework defining the acceptable standard of care for heart failure with reduced ejection fraction

Background

In heart failure with reduced ejection fraction (HFrEF), uptitration of neurohormonal antagonists to trial-proven doses shown to reduce mortality is challenging and seldomly achieved in clinical practice. A major reason for underdosing of these agents is the lack of a clear description of what constitutes an acceptable standard of care in HFrEF. To address this limitation, a novel framework for describing the physician adherence to evidence-based treatment was recently proposed. The aim of our study was to evaluate and validate the proposed framework in a real-world population of patients with HFrEF.

Methods

A cohort of patients with HFrEF, defined as left ventricular ejection fraction (LVEF) <40%, under treatment with neurohormonal antagonists for at least 3 months were retrospectively identified at a tertiary hospital's Heart Failure Clinic. Demographic, clinical, echocardiographic and treatment data were assessed. Patients were divided in three strata for each neurohormonal antagonist, according to the proposed framework: Status I – patients receiving target doses or the highest tolerated dose; Status II – use of subtarget doses for reasons unrelated to clinically important intolerance; and Status III – not receiving the drug at any dose. The prognostic value of each strata was assessed for all-cause mortality.

Results

A total of 408 patients (mean age 68±12 years, 78% male, 63% ischemic etiology) were included. The median LVEF was 31% (IQR 25–36) and most patients were in NYHA class II or III [210 (51.5%) and 163 (40%), respectively]. Medical therapy is described in Table 1. During a median follow-up of 3.3 years (IQR 1.4–5.6), 210 patients died. On univariable analysis, achieving Status I of beta-blocker (BB) therapy (HR: 0.50; 95% CI: 0.32–0.81; P=0.004) or ACEi/ARB (HR: 0.56; 95% CI: 0.36–0.86; P=0.012) was associated with reduced all-cause mortality. The mortality of patients in Status II of BB or ACEi/ARB was similar to the mortality of those not receiving the drug (HR for BB: 0.90; 95% CI: 0.53–1.52; P=0.69 and HR for ACEi/ARB: 0.71; 95% CI: 0.42–1.18; P=0.182) – figure 1. Achieving Status I of BB remained independently associated with reduced mortality after adjustment for several clinical and echocardiographic confounders (n=13) (adjusted HR: 0.59; 95% CI: 0.35–0.98; P=0.041).

Conclusions

In this real-world population of patients with HFrEF, the vast majority of patients were in Status I of BB and ACEi/ARB therapy. Achieving Status I of BB therapy seems to be associated with reduced mortality, even after adjustment for several markers of disease severity, highlighting the need for uptitration of medical therapy to maximal tolerated doses according to trial-proven regimens.

Funding Acknowledgement

Type of funding sources: None.

Cardiovascular disease in an intensive care unit: patterns of an often fatal omen

Background

Care for the critically ill patient with Cardiovascular Disease (CVD) requires a unique management approach, as the theoretical critical threshold for decompensation is lower and inherent adaptive mechanisms may be compromised. We aimed to characterize the prognostic impact of CVD in patients admitted to an Intensive Care Unit (ICU).

Methods

We performed a cohort study of consecutive patients admitted to an ICU from January to December 2019. Patients were stratified as follows: (1) established CVD – presence of either atrial fibrillation, heart failure, coronary artery disease and/or peripheral artery disease; (2) at higher risk of CVD – known arterial hypertension, dyslipidemia, diabetes mellitus and/or current smoking, in the absence of established CVD; and (3) at lower risk of CVD – i.e. none of the above. The co-primary endpoints were all-cause death in ICU and death during index hospitalization.

Results

During 2019, there were 334 admissions in ICU, comprising a total of 296 patients (mean age 67±15 years, 58.1% male). Overall, 69 (23.3%) and 108 (36.5%) died in ICU and during index hospitalization, respectively. Compared to patients at lower risk of CVD, those at higher CVD risk or with established CVD had markers of more severe disease, as noted by higher risk scores (e.g., SAPS-II 35.0±20.0 vs. 43.5±22.3 vs. 52.6±20.0; p<0.001), higher rates of mechanical ventilation (41.5 vs. 57.3 vs. 63.9%; p=0.020), shock during ICU stay (34.0 vs. 52.7 vs. 66.9%; p<0.001) and acute kidney injury (26.4 vs. 35.5 vs. 57.9%; p<0.001), respectively, as well as higher death rates in ICU (5.7 vs. 21.8 vs. 31.6%; p=0.001) and index hospitalization (9.4 vs. 37.3 vs. 46.6%; p<0.001). In multivariate analysis, adjusted for age and cause of admission, established CVD independently predicted the risk of all-cause death in ICU (HR: 2.084; 95% CI: 1.136–3.823; p=0.018) and during index hospitalization (HR 1.712; CI: 1.009–2.889; p=0.046). The analysis for the group of patients at higher risk of CVD yielded similar results to the abovementioned.

Conclusion

Roughly 4 in every 5 patients admitted in ICU were at risk of or had established CVD. The presence of either of the above independently predicted a two- to three-fold higher risk of death during hospitalization. Our findings emphasize the considerable burden of CVD in ICU and underscore the importance of comprehensive management of the complex critically ill patient.

Funding Acknowledgement

Type of funding sources: None.

The right ventricle: pairing structural with functional assessment

Background

Right Ventricular (RV) dysfunction is a well-recognized prognostic marker in the natural history of left-sided Heart Failure (HF). Common experience dictates that structural and functional evaluation are often seemingly discrepant. We aimed to evaluate the correlation between RV function by transthoracic echocardiography (TTE) and Right Heart Catheterization (RHC) parameters, and their prognostic value in patients with HF.

Methods

We designed a retrospective single-centre study of patients with advanced HF referred to TTE and RHC as part of Heart Transplant candidacy evaluation, from 2010 to 2019. Pulmonary Hypertension (PH) was defined by a mean pulmonary artery pressure (mPAP) ≥25mmHg. Patients with PH other than Group II (WHO) PH were excluded. In appropriate cases, vasodilator challenge with inhaled NO was performed. The primary endpoint was a composite of death, heart transplant or HF hospitalization at 6 months.

Results

The cohort was comprised of 68 patients (mean age 56±11 years, 73.5% male, ischaemic HF 44.1%). Most patients had PH (n=61) and TTE evidence of RV dysfunction (n=46). The strongest correlations between RHC and TTE parameters were moderate at best – mPAP, pulmonary capillary wedge pressure and central venous pressure with E/A ratio (Pearson r 0,461, 0,533 and 0,543, respectively; p<0.05); and RV stroke work index and mPAP with non-invasive estimated systolic pulmonary artery (PA) pressure (Pearson r 0,483 and 0,481, respectively; p<0.05). Over a median follow-up of 26 (12–42) months, 53 patients had a primary endpoint event, of whom 36 within 6 months. The best model integrating data from structural and functional assessment to predict the primary endpoint included the systolic PA pressure to stroke volume ratio – i.e. PA elastance (HR per 0.10 units: 2.817; 95% CI 1.030–1.338; p=0.016) – and RV free wall longitudinal strain (HR per −1%: 0.792; 95% CI 0.656–0.956; p=0.015). ROC curve analysis disclosed the best cut-off values as follows: 1.3 (sensitivity 77.2%, specificity 65.6%) and −18% (sensitivity 10.7%, specificity 86.4%), respectively.

Conclusion

In a cohort of patients with advanced HF, who were potential candidates for heart transplantation, RV dysfunction was often noted. The model with highest accuracy to predict the primary outcome integrated RV structural with functional data. Additional studies are warranted to define well-validated scores useful in the algorithmic therapeutic decision of advanced HF.

Funding Acknowledgement

Type of funding sources: None.

The gray zone of myocardial fibrosis is a better predictor of ventricular arrhythmias than total myocardial fibrosis in patients with previous myocardial infarction

Background

Current sudden cardiac death (SCD) risk stratification relies heavily on the assessment of left ventricular ejection fraction (LVEF), but markers that could refine risk assessment are needed. Total fibrosis mass (TFM) and “gray zone” of myocardial fibrosis (GZF) on late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) have been proposed as potential arrhythmogenic substrates. The aim of our study was to determine whether TFM and GZF can predict the occurrence of ventricular arrhythmias in patients with previous myocardial infarction.

Methods

We performed a single centre retrospective study enrolling all consecutive patients with previous myocardial infarction undergoing LGE-CMR before implantable cardioverter-defibrillator (ICD) implantation for primary or secondary prevention. TFM and GZF were defined as myocardial tissue with signal-intensities >6 SD and 2–6 SD above the mean of reference myocardium, respectively. The primary endpoint was a composite of sudden arrhythmic death, appropriate ICD shock, ventricular fibrillation (VF), or sustained ventricular tachycardia (VT) as detected by the device.

Results

A total of 55 patients (mean age 62±12 years, 87% male, mean LVEF 30% ± 8%) were included. During a mean follow-up period of 34±15 months, 10 patients reached the primary endpoint (8 appropriate ICD shock, 2 sustained VT or VF). Patients who attained the primary endpoint had similar TFM (28.6g ± 14.5 vs. 23.1g ± 14.5; P=0.283) but larger GZF (25.3g ± 11.0 vs 15.6g ± 7.3; P=0.001). After adjustment for LVEF, GZF remained independently associated with the composite arrhythmic endpoint (adjusted hazard ratio [aHR]: 1.10; 95% CI: 1.03–1.17; P=0.005), whereas TFM did not (aHR: 1.02; 95% CI: 0.98–1.06; P=0.394). Decision tree analysis identified 16.4g of GZF as the best cut-off to predict life-threatening arrhythmic events. The primary endpoint occurred in 9 out of the 22 patients (41%) with GZF >16.4g, but in only 1 of the 33 patients (3%) with GZF ≤16.4g – Figure.

Conclusions

The extent of GZF seems to be a better predictor of ventricular arrhythmias than TFM. This LGE-CMR parameter may be useful to identify a subgroup of patients with previous myocardial infarction at an increased risk of life-threatening arrhythmic events.

Funding Acknowledgement

Type of funding sources: None.

The odyssey to dethrone LV ejection fraction continues: the prognostic value of LV global function index in heart failure

Background

Left Ventricular (LV) Global Function index (LVGFi) is a parameter that combines data from global systolic performance and volumetric anatomical information, measurable by non-contrast Cardiac Magnetic Resonance (CMR). We aimed to evaluate whether LVGFi predicts major cardiovascular outcomes and outperforms LV ejection fraction (LVEF) in Heart Failure (HF).

Methods

We conducted a retrospective single-centre study of consecutive patients with HF who were referred to and had a LVEF <50% at CMR. Other than inadequate images for endocardial or epicardial border delineation, there were no exclusion criteria. LVEF was determined by 3D measurement. LVGFi was calculated as the LV stroke volume to the LV global volume ratio (Figure 1). The primary endpoint was a composite of time to all-cause death or HF hospitalization.

Results

The cohort was comprised of 433 HF patients (mean age 64±12 years, 74.1% male, ischaemic HF 53.1%, NYHA I-II 83.9%) with a mean LVEF of 33.5±10.0% and LVGFi of 22.8±7.4%. Over a median follow-up of 27 (17–37) months, 85 (19.6%) met the primary endpoint and 42 (9.7%) died. Patients with an event of the primary endpoint had markers of more severe HF, as noted by a reduced functional capacity (NYHA I-II: 63.5 vs. 89.0%; p<0.001) and increased natriuretic peptides [NT-proBNP: 2664 (1022–27242) vs. 791 (337–7258); p<0.001). Likewise, CMR showed higher LV volumes (e.g., LV end-diastolic volume index: 137±50 vs. 120±43mL/m2; p=0.001) and reduced LV performance indices, namely LVEF (29.2±10.6 vs 34.5±9.6%; p<0.001) and LVGFi (19.8±7.4 vs 23.6±7.3%; p<0.001). Both LVEF and LVGFi independently predicted the primary endpoint in multivariate analysis (separately imputed into a model adjusted for NYHA, NT-proBNP and creatinine). The LVEF model was more powerful than that of LVGFi. Similarly, LVGFi did not provide incremental prognostic information over LVEF in c-statistics analysis (0.653 vs. 0.622; p=0.645) (Figure 2).

Conclusion

While LVGFi independently predicted major outcomes in patients with HF and LVEF <50%, it did not surpass LVEF. Our findings contrast to those demonstrating LVGFi as a powerful variable that outperforms LVEF in hypertrophic cardiomyopathy, cardiac amyloidosis, and healthy subjects at risk of developing structural heart disease. We hypothesize that LVGFi might be primarily useful in the prognostic stratification of patients with preserved LVEF.

Funding Acknowledgement

Type of funding sources: None. Figure 1Figure 2

Pre-test probability of obstructive coronary artery disease in the new guidelines: too much, too little or just enough?

Background

Previous 2013 ESC guidelines recommended the use of the Modified Diamond-Forrester method to assess the pre-test probability (PTP) of obstructive coronary artery disease (CAD). The 2019 ESC Chronic Coronary Syndrome guidelines updated this recommendation with a major downgrade in PTP. The aim of this study was to compare the performance of these two methods in patients with stable chest pain undergoing coronary computed tomography angiography (CCTA) for suspected CAD.

Methods

We performed a retrospective analysis on prospectively collected data from a cohort of consecutive patients undergoing CCTA for suspected CAD from October 2016 to 2019. Key exclusion criteria were age <30 years-old, known CAD, suspected acute coronary syndrome or symptoms other than chest pain. Obstructive CAD was defined as any luminal stenosis ≥50% on CCTA. Whenever invasive coronary angiography (ICA) was subsequently performed, patients were reclassified if luminal stenosis was <50%. The two PTP prediction models were assessed for calibration and discrimination.

Results

A total of 320 patients (median age 63 years [IQR 53–70], 59% women) were included. Chest pain characteristics were: 48% atypical angina, 38% non-anginal chest pain, 14% typical angina. The observed prevalence of obstructive CAD was 16.3% (n=52). Patients with obstructive CAD were more often male, were significantly older and had a higher prevalence of typical angina and cardiovascular risk factors (except for family history of CAD). On average, individual PTP was 22.1% lower in the new guidelines. The 2013 prediction model significantly overestimated the likelihood of obstructive CAD (mean PTP 37.3% vs 16.3%; relative overestimation of 130%, p-value for miscalibration 0.005). The updated 2019 method showed good calibration for predicting the likelihood of obstructive CAD (mean PTP 15.2% vs 16.3%; relative underestimation of 6.5%, p-value for miscalibration 0.712). The two approaches showed similar discriminative power, with a C-statistics of 0.730 and 0.735 for the 2013 and 2019 methods, respectively (p-value for comparison 0.933). Stratification by gender produced similar results.

Conclusions

In patients with stable chest pain undergoing CCTA, the updated 2019 prediction model allows for a more precise estimation of pre-test probabilities of obstructive CAD than the previous model. Adoption of this new score may improve disease prediction and change the downstream diagnostic pathway in a significant proportion of cases.

Graph 1

Funding Acknowledgement

Type of funding source: None

Disproportionate functional mitral regurgitation: clinical validation of a new conceptual framework

Background

Disproportionate functional mitral regurgitation (FMR) is a novel concept that tries to identify hemodynamically significant FMR by readjusting the effective regurgitant orifice area (EROA) and regurgitant volume (RegVol) cut-offs according to left ventricular end-diastolic volume (LVEDV) and left ventricular ejection fraction (LVEF). However, this theoretical concept lacks clinical validation. The aim of this study was to assess the clinical significance of disproportionate FMR.

Methods

Patients with at least mild FMR and reduced LVEF (<50%) who underwent transthoracic echocardiography between 2010 and 2014 were retrospectively identified in our laboratory database. Optimal medical therapy (including cardiac resynchronization when indicated) for ≥3 months was a prerequisite for inclusion. Hemodynamically significant FMR was defined as regurgitant fraction >50% and the patient-specific theoretical RegVol cut-off was calculated according to the formula presented in Fig. 1a. The difference between the estimated RegVol by the PISA method and the theoretical RegVol cut-off was considered to represent the haemodynamic burden of MR. The primary endpoint was all-cause death. Patients were censured if mitral intervention or heart transplant was undertaken. Survival analysis was used to assess the effect of disproportionate FMR on mortality in 2 subgroups (LVEF <30% and 30–49%).

Results

A total of 289 patients (median age 69 years [IQR 60–77], 75% male, 53% of ischemic aetiology) were included. More than 90% were on beta-blockers and renin-angiotensin inhibitors, 44% on aldosterone receptor antagonists, and 73% had implanted devices. The median LVEF and LVEDV were 34% (IQR 27–41) and 170mL (IQR 128–220), respectively. Median EROA was 10mm2 (IQR 3–21) and RegVol was 15 mL (IQR 4–30). RegVol distribution across the cohort was: <10mL: 41%; 10–20mL: 18%; 20–30mL: 15% and >30mL: 26%. Disproportionate FMR was present in 83 patients (29%). These patients had significantly higher SPAP values (41mmHg [IQR 33–50] vs. 33mmHg [IQR 29–40]; p<0.001).

During a median follow-up of 44 months (IQR 19–73), 106 patients died. In the LVEF <30% subgroup, age (HR 1.05 per year [1.02–1.08]; p<0.001), LVEF (HR 0.94 per 1% [0.89–0.99]; p=0.042) and TAPSE (HR 0.92 per mm [0.86–0.99]; p=0.030) were independent predictors of mortality. In the LVEF 30–49% subgroup, age (HR 1.05 per year [1.02–1.08]; p=0.003), LVEF (HR 0.94 per 1% [0.89–0.99]; p=0.020) and disproportionate FMR (HR 1.02 per mL [1.01–1.03]; p=0.01) were independently associated with increased mortality.

Conclusions

Disproportionate FMR proved to be an important independent predictor of mortality in patients with LVEF between 30–49%. These findings were not replicated in those with LVEF<30%, where the degree of biventricular dysfunction seems to outweigh all other echocardiographic parameters, leaving FMR as a bystander.

Figure 1

Funding Acknowledgement

Type of funding source: None

P3382Vascular calcium Index: an imaging tool to predict vascular complications and major bleeding in TF-TAVI

Introduction

Vascular calcification has been associated with worse outcomes in transfemoral TAVI (TF-TAVI). However, there is currently no simple method to assess it and identify different patterns of calcification in an objective and quantitative manner. The purpose of this study was to develop a quantitative score of aortic (Ao) and ileofemural (IF) calcification and to assess its ability to predict life-threatening bleeding (LTB) and major vascular complications during TF-TAVI.

Methods

Case-control single center retrospective study of patients undergoing TF-TAVI between Nov2015 and Aug2018 including 183 consecutive patients (99 women, mean age 83±3 years, mean Euroscore II - ESII - 6.0±4.1). The Vascular Calcium Score was calculated for the entire Ao and IF vessels using a modified Agatston score derived from contrast-enhanced CT images, with calcium threshold locally adjusted for luminal attenuation (mean attenuation + 5x SD). A luminal attenuation threshold >600UH impaired vascular calcium evaluation and patients were excluded. LTB and major vascular complications were adjudicated according to the VARC-2 classification and identified by chart review by and independent team.

Results

Thirty patients (16%) suffered major bleeding and 13 (7%) experienced LTB. Major vascular injury occurred in 11 patients (6%). The median total vascular calcium score (TCS) was 11752 AU (IQR: 6388–19844) and median IF score (IFS) was 2210AU (IQR: 865–4170). TCS indexed for body surface area (TCSi) was predictor of LTB (AUC: 0.78±0.07, p<0.05) and of major vascular complications (AUC: 0.85±0.05, p<0.05). After multivariate analysis, iTCS and glomerular filtration rate (GFR) remained as predictors of LTB with an HR of 1.11 for each increase in 1000UA/m2 of TCSi (95% CI: 1.03–1.18) and 0.94 (95% CI: 0.88–0.985) respectively, independently of the ESII. iTCS and GFR were also independently associated with major vascular complications (p<0.05). Patients with an iTCS above 9750AU/m2 have an odds ratio of 7.7 (95% CI: 2.0 - 29.2) for LTB. This cut-off has a sensitivity of 77% and a specificity of 70% for LTB. Similarly, patients with an iTCS above 9750AU/m2 have an odds ratio of 10.3 (95% CI: 22 - 49.3) for major vascular injury.

Conclusions

A quantitative score for vascular calcification in contrast-enhanced CT images was developed. iTCS was independently associated with life-threatening bleeding and major vascular complications.

Cardiorespiratory Adaptations in Elderly Men Following Different Concurrent Training Regimes

BACKGROUND

This study aimed to investigate the effects of different intra-session exercise orders during concurrent training (CT) on endurance performance in elderly men, as well as to verify its influence on individual responses in endurance performance.

DESIGN

Twenty-five healthy elderly men (64.7 ± 4.1 years) were placed into two groups: strength training prior to endurance training (SE, n=13), and one in the reverse order (ES, n=12). CT was performed three times a week during 12 weeks. Before and after training, peak oxygen uptake (VO2peak), maximal workload (Wmax), absolute and relative cycling economy at 25, 50, 75 and 100 W (i.e., average VO2 at different stages) were assessed.

RESULTS

Similar increases in VO2peak were observed in the SE and ES groups (SE: 8.1 ± 9.9%; ES: 9.3 ± 9.8%; P<0.001), as well as in Wmax (SE: 19.9 ± 19.3%; ES: 24.1 ± 24.0%; P<0.001). Moreover, significant reductions were observed in the absolute VO2 at 100 W (P<0.05) in the SE and ES groups. No difference between groups was observed. In the ES group, one subject did not respond positively in terms of both VO2max and Wmax, whereas 4 subjects did not respond positively in terms of both VO2max and Wmax in SE group.

CONCLUSIONS

CT improved maximal and submaximal endurance performance in elderly men, independent of intra-session exercise order. However, it seems that the ES order elicited more individual responsiveness in terms of maximal endurance performance than SE order.

Quality of Life of Children and Youngsters who Attended the Psycho-Educational Program “+ Familia” (+family)

The program “+ Família” part of the activities promoted by CLDS + from Paredes de Coura in 2015, has enabled to act at the level of strategy development for qualifying families. The perceived quality of life of children and youngsters was evaluated in 2 moments: at the beginning (n = 23) and in the end (n = 11). We used the scale kidscreen-10, translated and measured for the Portuguese population. At the first moment, the sample consisted of 65% of women and 35% man; 87% aged between 6 and 10 years old and 13% aged between 11 and 15 years old; 74% attended the 1st cycle of studies and 13% had some type of disability. Based on 4 of the questions, the perception of quality of life has improved, between the beginning and the end of the program implementation. So for the remaining 6 questions, quality of life was perceived in a more negative way in the same period. An intra subject analysis would have to be made in order to measure the results’ bias due to the absence of 12 subjects in the final evaluation.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Guide for adults in the children's therapeutic tale: “I conquered my fears”

The book “I conquered my fears” was created as a result of the clinical experience of the author. It is a therapeutic tale, which is valid as a resource to be used by health workers and parents so as to help children overcome their fears at bedtime.

Because experience is important for an adult so as to better reflect on the theme, the book also includes an appendix to help accordingly.

The adult is invited to express what he/she likes to hear the most and the least, when waking from a sleepless night, and is also invited to dynamically interact with the book, give answers and create hypothesis, with no fear of making mistakes.

The parents, after reading the book, refer a better stress management capacity at critical moments experienced with the children at bedtime.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Comparison of different breast planning techniques and algorithms for radiation therapy treatment

This work aims at investigating the impact of treating breast cancer using different radiation therapy (RT) techniques--forwardly-planned intensity-modulated, f-IMRT, inversely-planned IMRT and dynamic conformal arc (DCART) RT--and their effects on the whole-breast irradiation and in the undesirable irradiation of the surrounding healthy tissues. Two algorithms of iPlan BrainLAB treatment planning system were compared: Pencil Beam Convolution (PBC) and commercial Monte Carlo (iMC). Seven left-sided breast patients submitted to breast-conserving surgery were enrolled in the study. For each patient, four RT techniques--f-IMRT, IMRT using 2-fields and 5-fields (IMRT2 and IMRT5, respectively) and DCART - were applied. The dose distributions in the planned target volume (PTV) and the dose to the organs at risk (OAR) were compared analyzing dose-volume histograms; further statistical analysis was performed using IBM SPSS v20 software. For PBC, all techniques provided adequate coverage of the PTV. However, statistically significant dose differences were observed between the techniques, in the PTV, OAR and also in the pattern of dose distribution spreading into normal tissues. IMRT5 and DCART spread low doses into greater volumes of normal tissue, right breast, right lung and heart than tangential techniques. However, IMRT5 plans improved distributions for the PTV, exhibiting better conformity and homogeneity in target and reduced high dose percentages in ipsilateral OAR. DCART did not present advantages over any of the techniques investigated. Differences were also found comparing the calculation algorithms: PBC estimated higher doses for the PTV, ipsilateral lung and heart than the iMC algorithm predicted.

Decreased prostate cancer cell migration by inhibition of the insulin-like growth factor II/Mannose-6-Phosphate receptor

The 270-kDa insulin-like growth factor II (IGF-II)/cation-independent mannose-6-phosphate receptor (MPR) is a multifunctional receptor protein. Endocytoses and intracellular transport of soluble enzymes bearing mannose6-phosphate (M-6-P) residues to lysosomes is mediated by the IGF-II/MPR. We examined human prostate cancer cells for IGF-II/MPR expression to determine whether this receptor mediates cell migration. PC3 human prostate cancer cells were studied for intracellular IGF-II/MPR by immunoblotting. PC3 cell surface IGF-II/MPR expression was assessed by flow cytometric analysis. Cell motility was quantitated by a scratch migration assay, and IGF-II/MPR blockade was achieved using M-6-P or affinity-purified rabbit anti-bovine cation-independent IGF-II/MPR immunoglobulin. IGF-II/MPR is expressed in the cytoplasm and on the surface of PC3 prostate cancer cells. The mean number of PC3 cells migrating per high powered field in medium containing polyclonal anti-IGF-II/MPR immunoglobulin or M-6-P decreased significantly (5 ± 4 cells and 34 ± 5 cells, respectively) compared with control medium containing mouse immunoglobulin G (70 ± 12 cells) or mannose-1-phosphate (67 ± 7 cells). This decreased PC3 cell migration following cell surface IGF-II/MPR blockade suggests that the IGF-II/MPR may play an important role in prostate cancer cell motility.

Urokinase plasminogen activator amino-terminal peptides inhibit development of the rat ventral prostate

The plasma membrane urokinase plasminogen activator receptor (uPAR) localizes and enhances activation of pro-uPA. Active uPA, in turn, promotes increased degradation of the extracellular matrix (ECM) by activation of plasminogen. uPAR binds to ECM molecules and integrins, which can affect cellular adhesion, signal transduction, and gene regulation. The current study examines the expression and function of uPAR in developing rat ventral prostates (VPs). We report that newborn VPs express uPAR mRNA and protein. In addition, the function of uPAR-bound uPA during in vitro prostatic development was studied by adding recombinant peptide competitive inhibitors of uPA-uPAR binding. Newborn VP explants were cultured in serum-free media for one week with 10(-8) M testosterone plus chimeric peptides containing a human immunoglobulin G Fc domain and either human uPA amino acids 1-138 (hu-uPA 1-138) as a control or mouse uPA amino acids 1-138 (mo-uPA 1-138) or 1-48 (mo-uPA 1-48). Hu-uPA 1-138-treated VPs underwent normal ductal branching morphogenesis and tissue differentiation. In contrast, VPs treated with mo-uPA 1-138 or mo-uPA 1-48 displayed a dose-dependent perturbation of ductal branching. Differentiation of both epithelial and mesenchymal tissues was also impaired. Mo-uPA 1-48-treated VPs contained significantly more apoptotic cells. These observations suggest that disruption of uPA binding to uPAR results in a retardation of the development of newborn VPs.

Cell differentiation lineage in the prostate

Prostatic epithelium consists mainly of luminal and basal cells, which are presumed to differentiate from common progenitor/stem cells. We hypothesize that progenitor/stem cells are highly concentrated in the embryonic urogenital sinus epithelium from which prostatic epithelial buds develop. We further hypothesize that these epithelial progenitor/stem cells are also present within the basal compartment of adult prostatic epithelium and that the spectrum of differentiation markers of embryonic and adult progenitor/stem cells will be similar. The present study demonstrates that the majority of cells in embryonic urogenital sinus epithelium and developing prostatic epithelium (rat, mouse, and human) co-expressed luminal cytokeratins 8 and 18 (CK8, CK18), the basal cell cytokeratins (CK14, CK5), p63, and the so-called transitional or intermediate cell markers, cytokeratin 19 (CK19) and glutathione-S-transferase-pi (GSTpi). The majority of luminal cells in adult rodent and human prostates only expressed luminal markers (CK8, CK18), while the basal epithelial cell compartment contained several distinct subpopulations. In the adult prostate, the predominant basal epithelial subpopulation expressed the classical basal cell markers (CK5, CK14, p63) as well as CK19 and GSTpi. However, a small fraction of adult prostatic basal epithelial cells co-expressed the full spectrum of basal and luminal epithelial cell markers (CK5, CK14, CK8, CK18, CK19, p63, GSTpi). This adult prostatic basal epithelial cell subpopulation, thus, exhibited a cell differentiation marker profile similar to that expressed in embryonic urogenital sinus epithelium. These rare adult prostatic basal epithelial cells are proposed to be the progenitor/stem cell population. Thus, we propose that at all stages (embryonic to adult) prostatic epithelial progenitor/stem cells maintain a differentiation marker profile similar to that of the original embryonic progenitor of the prostate, namely urogenital sinus epithelium. Adult progenitor/stem cells co-express both luminal cell, basal cell, and intermediate cell markers. These progenitor/stem cells differentiate into mature luminal cells by maintaining CK8 and CK18, and losing all other makers. Progenitor/stem cells also give rise to mature basal cells by maintaining CK5, CK14, p63, CK19, and GSTpi and losing K8 and K18. Thus, adult prostate basal and luminal cells are proposed to be derived from a common pleuripotent progenitor/stem cell in the basal compartment that maintains its embryonic profile of differentiation markers from embryonic to adult stages.

The BMP family member Gdf7 is required for seminal vesicle growth, branching morphogenesis, and cytodifferentiation

Epithelial-mesenchymal interactions play an important role in the development of many different organs and tissues. The secretory glands of the male reproductive system, including the prostate and seminal vesicles, are derived from epithelial precursors. Signals from the underlying mesenchyme are required for normal growth, branching, and differentiation of the seminal vesicle epithelium. Here, we show that a member of the BMP family, Gdf7, is required for normal seminal vesicle development. Expression and tissue recombination experiments suggest that Gdf7 is a mesenchymal signal that acts in a paracrine fashion to control the differentiation of the seminal vesicle epithelium.

The metaplastic effects of estrogen on mouse prostate epithelium: proliferation of cells with basal cell phenotype

The exogenous administration of estrogens to male mice alters the hypothalamic-pituitary-gonadal axis and reduces androgen levels, leading to a regression of the prostatic epithelium. As well, a specific direct response to estrogens is the induction of epithelial squamous metaplasia. The aims of this study were to identify the process by which the prostatic epithelium is transformed in intact adult male mice using the synthetic estrogen, diethylstilbestrol. A comparison of the effects of diethylstilbestrol in the three lobes revealed a hierarchy of response, with the anterior lobe being the most responsive, the dorsolateral lobe less responsive, and the ventral lobe the least responsive. The effect of castration was used to distinguish between the epithelial responses to estrogen administration and androgen deprivation. The results demonstrate that transformation of the epithelium involved proliferation of cells with a basal cell phenotype, the onset of cytokeratin 10 expression, up-regulation of progesterone receptor expression, and loss of the cell cycle inhibitor, p27(Kip1) expression; none of these changes was observed after castration. Mice lacking functional estrogen receptor alpha failed to respond, demonstrating a requirement for estrogen receptor alpha in the epithelium and/or stroma to mediate the proliferative response to estrogen in the prostate gland.

Mesenchymal-epithelial interactions in bladder smooth muscle development: effects of the local tissue environment

PURPOSE

We have previously shown that mesenchymal-epithelial interactions are necessary for the development of bladder smooth muscle. Specifically without fetal or adult urothelium embryonic rat bladder mesenchyma does not differentiate into smooth muscle. The mechanism responsible for this interaction is not known, although it is postulated that diffusable growth factors have a role. Our hypothesis is that diffusable factors within adult rat bladders influence smooth muscle differentiation.

MATERIALS AND METHODS

Chimeric bladders were created by surgically implanting 14-day embryonic rat bladder mesenchyma before smooth muscle differentiation into the detrusor space of adult syngeneic hosts to test whether the host urothelium would induce smooth muscle differentiation without being in direct contact with fetal bladder mesenchymal tissue. Sub-detrusor pockets were created between the serosa and smooth muscle layer, between the smooth muscle layer and lamina propria, and between the lamina propria and urothelium in direct contact with urothelium. Controls consisted of intact 14-day embryonic rat bladders with the urothelium not removed, and 14-day embryonic bladder mesenchyma recombined with urothelium (direct contact) placed within the sub-detrusor space of the bladder and under the renal capsule.

RESULTS

Immunohistochemical staining with antibodies directed against smooth muscle alpha-actin and urothelium (cytokeratin 7) revealed smooth muscle differentiation in intact embryonic bladders and bladder mesenchyma plus urothelium recombinants in contrast to bladder mesenchyma alone, which had no alpha-actin staining (morphometric smooth muscle analysis p = 0). There was no alpha-actin staining in chimeric bladders even when bladder mesenchymal grafts were placed directly in contact with host urothelium. In addition, bladder mesenchyma plus urothelial recombinants within the host bladder had less alpha-actin staining than their counterparts placed under the renal capsule (p = 0.001).

CONCLUSIONS

A diffusable factor most likely exists within adult rat bladders that inhibits smooth muscle differentiation.

Evidence that epithelial and mesenchymal estrogen receptor-alpha mediates effects of estrogen on prostatic epithelium

In combination with androgens, estrogens can induce aberrant growth and malignancy of the prostate gland. Estrogen action is mediated through two receptor subtypes: estrogen receptors alpha (ERalpha) and beta (ERbeta). Wild-type (wt) and transgenic mice lacking a functional ERalpha (alphaERKO) or ERbeta (betaERKO) were treated with the synthetic estrogen diethylstilbestrol (DES). DES induced prostatic squamous metaplasia (SQM) in wt and betaERKO but not in alphaERKO mice, indicating an essential role for ERalpha, but not ERbeta, in the induction of SQM of prostatic epithelium. In order to determine the respective roles of epithelial and stromal ERalpha in this response, the following tissue recombinants were constructed with prostatic epithelia (E) and stroma (S) from wt and ERKO mice: wt-S+wt-E, alphaERKO-S+alphaERKO-E, wt-S+alphaERKO-E, and alphaERKO-S+wt-E. A metaplastic response to DES was observed in wt-S+wt-E tissue recombinants. This response to DES involved multilayering of basal epithelial cells, expression of cytokeratin 10, and up-regulation of the progesterone receptor. Tissue recombinants containing alphaERKO-E and/or -S (alphaERKO-S+alphaERKO-E, wt-S+alphaERKO-E, and alphaERKO-S+wt-E) failed to respond to DES. Therefore, full and uniform epithelial SQM requires ERalpha in the epithelium and stroma. These results provide a novel insight into the cell-cell interactions mediating estrogen action in the prostate via ERalpha.

Clonality of urogenital organs as determined by analysis of chimeric mice

Though the first mammalian chimera was reported in 1961, suitable markers for different animal strains which are easily detectable in histological sections of all or most organs have not existed. Chimeric mice were produced having an excellent histological marker, the C3H antigen, which is strain-specific and fulfills all the criteria for an ideal strain-specific histological marker. Using male and female C3H-Balb/c chimeric mice we examined epithelial cells of urogenital organs and their morphological or functional units, such as the glomerulus, to determine whether individual organs and their morphological subunits were monoclonal or polyclonal in origin. We found that the epithelial parenchyma of most male and female urogenital organs (the prostate, seminal vesicle, epididymis, ovaries, vagina, kidney, ureter and bladder) and their morphological subdivisions were derived from cells of both input strains, indicating a polyclonal origin for each organ and/or organ component. A notable exception was the uterus in which all individual uterine glands examined (n = 403) were found to be either entirely Balb/c or entirely C3H, indicating a monoclonal origin. The clonality of urogenital structures is discussed in terms of the morphogenesis of the urogenital system.

Mesenchymal reprogramming of adult human epithelial differentiation

The objective of this study was to determine whether neonatal rat seminal vesicle mesenchyme (rSVM) can reprogram epithelial differentiation in a fully differentiated adult human bladder epithelium. For this purpose neonatal rSVM was isolated from newborn (0-day) Sprague-Dawley rats, and normal adult human bladder epithelium (hBLE) was isolated from radical cystoprostatectomy specimens to prepare rSVM+hBLE tissue recombinants in vitro. After overnight culture the tissue recombinants were grafted beneath the renal capsule of male athymic rodent hosts and allowed to grow in vivo for 6 months. As controls, rSVM and hBLE were grafted separately and allowed to grow for the same period. Tissue recombinants and control tissue grafts were harvested, and secretions were collected for biochemical studies. Tissues were fixed both for histologic as well as immunohistochemical staining. Neonatal rSVM induced normal adult human bladder urothelium to form glandular structures resembling prostate. The induced prostatic acini were filled with secretions that expressed human prostate-specific secretory proteins. These findings demonstrate that adult human urothelial cells retain a responsiveness to neonatal prostatic mesenchymal inductors. Change in urothelial histodifferentiation was associated with change in functional activity. The ability of the neonatal rat mesenchymal tissues to induce morphologic as well as biochemical changes in normal adult human urothelium provides a basis for human tissue engineering and organ reconstruction.

Neuroanatomical changes in the rat bladder after bladder outlet obstruction

OBJECTIVE

To investigate the histological changes in bladder innervation in response to partial bladder outlet obstruction in a rat model.

MATERIALS AND METHODS

Forty-eight adult female rats had their bladder outlet partially obstructed by ligating the proximal urethra over a 20 G angiocatheter; 18 shamoperated rats served as controls. Animals were killed after 1, 2 and 4 weeks, and their bladders evaluated using computerized morphometry. Immunohistochemical staining for neuronal protein gene-product 9.5 (PGP, a general neuronal marker) and enzyme histochemical staining of acetylcholinesterase, adrenergic fibres and nitric oxide synthase were performed.

RESULTS

Bladder wall changes after obstruction consisted of a six- to sevenfold increase in bladder volume and weight. Smooth muscle hypertrophy was evident equally at all sample times. Cystometry showed functional alterations in bladder capacity and voided pressures; obstructed animals had markedly increased bladder capacities and higher voiding pressures (obstructed, 80-100 cmH2O; normal, 30-40 cmH2O). Neuronal changes in the obstructed bladder were most dramatic within the cholinergic and adrenergic neurotransmitter systems within and surrounding the smooth muscle bundles, where there was less staining than in control animals. PGP immunoreactivity increased slightly. The L-arginine-nitric oxide pathway appeared unperturbed after obstruction.

CONCLUSIONS

These histological findings suggest that neuropathic changes in the bladder after outlet obstruction, including detrusor instability, are mainly the result of anatomical perturbations in the cholinergic and adrenergic pathways.

Stromal cells are critical targets in the regulation of mammary ductal morphogenesis by parathyroid hormone-related protein

Parathyroid hormone-related protein (PTHrP) was originally identified as the tumor product responsible for humoral hypercalcemia of malignancy. It is now known that PTHrP is produced by many normal tissues in which it appears to play a role as a developmental regulatory molecule. PTHrP is a normal product of mammary epithelial cells, and recent experiments in our laboratory have demonstrated that overexpression or underexpression of PTHrP in the murine mammary gland leads to severe disruptions in its development. The nature of these phenotypes suggests that PTHrP acts to modulate branching growth during mammary development by regulating mammary stromal cell function. We now demonstrate that throughout mammary development, during periods of active ductal-branching morphogenesis, PTHrP is produced by epithelial cells, whereas the PTH/PTHrP receptor is expressed on stromal cells. In addition, we show that mammary stromal cells in culture contain specific binding sites for amino terminal PTHrP and respond with an increase in intracellular cAMP. Finally, we demonstrate that the mammary mesenchyme must express the PTH/PTHrP receptor in order to support mammary epithelial cell morphogenesis. These results demonstrate that PTHrP and the PTH/PTHrP receptor represent an epithelial/mesenchymal signaling circuit that is necessary for mammary morphogenesis and that stromal cells are a critical target for PTHrP's action in the mammary gland.

Mesenchymal-epithelial interactions in bladder smooth muscle development: epithelial specificity

PURPOSE

We previously showed that mesenchymal-epithelial interactions are necessary for the development of bladder smooth muscle. Specifically without bladder epithelium embryonic bladder mesenchyme does not differentiate into smooth muscle. We determine whether this process is specific to bladder epithelium or whether epithelial cells from other organ systems induce bladder mesenchyme to differentiate into smooth muscle, as well as whether epithelial age is an important variable.

MATERIALS AND METHODS

We recombined 14-day bladder mesenchyme before smooth muscle differentiation with rat epithelium from 14-day, 19-day, newborn and adult bladder, ureter, colon, ileum, stomach, cornea and epidermis. In addition, bladder epithelium was recombined with 14-day embryonic small intestinal, 14-day embryonic gastric and newborn seminal vesicle mesenchyme. All tissue recombinants were grafted under the renal capsule of an adult rat syngeneic host for 3 weeks.

RESULTS

Immunohistochemical analysis with antibodies directed against smooth muscle alpha-actin revealed that all epithelial types studied induced bladder mesenchyme to differentiate into smooth muscle, although to different degrees. Induction of smooth muscle was independent of urothelial age. In addition, bladder epithelium induced intestinal, gastric and seminal vesicle mesenchyme to differentiate into smooth muscle and express an overall morphological pattern indicative of the bladder fibromuscular wall.

CONCLUSIONS

The mechanism whereby urothelium induces bladder mesenchyme to differentiate into smooth muscle is not specific to embryonic urothelium. Older urothelium and heterotypic epithelium also induce smooth muscle differentiation. With the common use of bowel, stomach and ureteral segments for bladder augmentation it is important to understand the interaction of different types of epithelium with the native bladder.

Androgens and masculinization of genitalia in the spotted hyaena (Crocuta crocuta). 1. Urogenital morphology and placental androgen production during fetal life

According to common understanding of sexual differentiation, the formation and development of a penile clitoris in female spotted hyaenas requires the presence of naturally circulating androgens during fetal life. The purpose of the present study was to determine potential source(s) of such fetal androgens by investigating the timing of urogenital development and placental production of androgen during early and mid-gestation. Fetuses determined to be female by molecular techniques (lack of SRY gene) at days 33 and 48 of gestation had undifferentiated gonads, but the clitoris was already 'masculinized' and was generally similar to the phallus of a 50-day-old male fetus. Wolffian and Müllerian ducts terminated at the urogenital sinus in both sexes and a urethra was present along the entire length of the clitoris and penis. The adrenal gland was large and histologically differentiated at 33 days. Steroid gradients across the uterus (a drop in delta 4-androstenedione, with increases in oestrogen and androgen), and high androstenedione in ovarian veins indicated that ovarian androstenedione was metabolized and secreted as testosterone by the placenta throughout gestation. In vitro, whole or homogenized placentae at days 48 and 58 of gestation (110 days total) metabolized radiolabelled androstenedione into testosterone and oestradiol; the specific enzymatic activity of early placental tissues was higher than at later stages. A human placental homogenate had higher aromatase activity but did not produce testosterone unless aromatase was inhibited. Infusion of labelled androstenedione into the uterine arteries of hyaenas demonstrated the conversion of this substrate into testosterone and oestradiol and their secretion into the fetal circulation. Evidently, androgen is produced by the placenta and secreted into the fetal circulation from early in pregnancy when masculinization is first evident, before differentiation of the fetal ovary.

Hyaluronan is a prerequisite for ductal branching morphogenesis

Hyaluronan, a macromolecular carbohydrate polymer of the extracellular matrix is prominent early in embryogenesis, coinciding with rapid tissue growth. CD44, the predominant receptor for hyaluronan on vertebrate cells, is a variably expressed transmembrane glycoprotein. Mouse anterior prostate glands obtained at various postnatal time points were examined for the expression of hyaluronan and CD44. Reverse transcriptase polymerase chain reaction analysis was used to map the temporal regulation of specific CD44 variant isoforms. In each age group, hyaluronan was localized exclusively in the stromal matrix. Hyaluronan was greatly reduced in the later ages and was entirely absent around the developmentally quiescent proximal regions of the ducts. Early in prostate development, CD44 was prominent in the mesenchyme. However, in the later phases, CD44 expression became associated with membranes of epithelial cells. The role of hyaluronan-CD44 interactions in ductal branching morphogenesis was studied by serum-free organ culture of mouse anterior prostate. In the presence of optimal levels of testosterone, the organs underwent ductal branching morphogenesis. Treatment with either neutralizing anti-CD44 antibodies, hyaluronan hexasaccharides or the enzyme hyaluronidase inhibited androgen-stimulated ductal branching morphogenesis. These results are suggestive of the significant role played by hyaluronan-CD44 interactions in mediating androgen-induced prostatic growth and morphogenesis.

Inhibition of prostate cancer neovascularization and growth by urokinase-plasminogen activator receptor blockade

Binding of the serine protease urokinase (u-PA) to its receptor on tumor cell surfaces facilitates proteolysis and tumor invasion. We undertook this study to determine whether the role of u-PA in prostate cancer induced angiogenesis and secondary tumor growth by developing a homologous, immunocompetent in vivo model in which the tumors cells secrete an inhibitor of the murine u-PA receptor. A mutant recombinant murine u-PA that retains receptor binding but not proteolytic activity was made by PCR mutagenesis. Mutant u-PA and a reporter gene pRK luciferase were transfected and stably expressed in the highly metastatic rat Dunning MAT-LyLu prostate cancer cell line. Several clones expressing mutant u-PA and luciferase were identified by Western blotting, plasminogen zymography, and reverse transcription-PCR. One of these clones, 5C4, was injected s.c. into Copenhagen rats. Compared to animals injected with clones expressing pRK luciferase alone, tumors in animals injected with 5C4 cells were significantly smaller. Moreover, there were fewer lung micrometastases in the 5C4 animals. Primary tumor angiogenesis was measured by microvessel quantification of tissue stained with antibodies against von Willebrand factor. Mean microvessel density in 5C4 tumors was 4.3-fold lower than that in animals with tumors derived from the control tumor cell line (P < 0.0001). Significant inhibition of tumor growth was also observed for two additional MAT-LyLu cell lines expressing mutant u-PA. These findings suggest that cell surface u-PA contributes to prostate cancer growth by enhancing angiogenesis.

Upregulation of the 72-kDa type IV collagenase in epithelial and stromal cells during rat tracheal gland morphogenesis

Submucosal glands secrete most of the mucus that lubricates the tracheal surface and protects it from irritants and infection. These glands develop postnatally in the rat, permitting convenient study of the mechanisms controlling this process. One such mechanism involves degradation of the supportive connective tissue matrix at the front of the growing glands. We recently showed that tracheal gland cell invasion of collagen gels in vitro is dependent on secretion of a 72-kDa type IV collagenase. In the present study, we show that the activity of this enzyme (also referred to as matrix metalloproteinase-2 or gelatinase A) is elevated at the time of gland development in vivo. That this increase is at least partly mediated at the level of steady-state mRNA was indicated by semiquantitative PCR analysis of gland-enriched, microdissected tissue samples. Immunohistochemistry revealed that the enzyme was present at the interface between the glands and extracellular matrix. In situ hybridization revealed that the cognate mRNA was present in epithelial cells of glands undergoing morphogenesis (particularly Postnatal Day 7) but not in those of adult glands or the surface epithelium. At all ages, stromal cells below the surface epithelium were labeled; labeling intensity was highest at the time and location of gland morphogenesis. These findings suggest that the 72-kDa type IV collagenase is developmentally regulated in gland and stromal cells at the level of steady-state mRNA and plays a role in the degradation of extracellular matrix during tracheobronchial gland morphogenesis.

Msx1 (Hox-7.1) in the adult mouse uterus: cellular interactions underlying regulation of expression

We report here that Msx1 (formerly Hox-7.1) is expressed at high levels in uterine epithelial cells of the non-pregnant adult. These cells undergo pronounced changes in morphology in response to embryo implantation and show a concomitant decrease in Msx1 levels. While Msx1 is restricted to the uterus in adulthood, we observe Msx1 expression throughout the entire perinatal Mullerian duct epithelium in the prospective uterus, cervix and vagina. Through analysis of tissue recombinants, the expression of Msx1 in the epithelium was shown to be dependent upon an interaction with the underlying mesenchyme of uterine origin. The capacity of uterine mesenchyme to support or induce Msx1 expression in Mullerian epithelium is correlated with mesenchymal expression of Wnt-5a. Whereas Msx1 expression in the epithelium results from interaction with uterine mesenchyme, Wnt-5a expression is an intrinsic property of the uterine mesenchyme and does not depend upon the epithelium. The observation that Msx1 is expressed in the adult uterine epithelium and that conversion of the presumptive vaginal epithelium to uterine epithelium can be elicited only during the first week of postnatal development when Msx1 expression is detected suggests that, in addition to regulating various aspects of uterine epithelial morphology and function (e.g. gestation), this homeobox-containing gene plays a role in maintaining the uterus in a morphogenic and developmentally responsive state prerequisite for its unique function.