[123I]CC1: A PARP-Targeting, Auger Electron-Emitting Radiopharmaceutical for Radionuclide Therapy of Cancer

Poly(adenosine diphosphate ribose) polymerase (PARP) has emerged as an effective therapeutic strategy against cancer that targets the DNA damage repair enzyme. PARP-targeting compounds radiolabeled with an Auger electron-emitting radionuclide can be trapped close to damaged DNA in tumor tissue, where high ionizing potential and short range lead Auger electrons to kill cancer cells through the creation of complex DNA damage, with minimal damage to surrounding normal tissue. Here, we report on [123I]CC1, an 123I-labeled PARP inhibitor for radioligand therapy of cancer. Methods: Copper-mediated 123I iododeboronation of a boronic pinacol ester precursor afforded [123I]CC1. The level and specificity of cell uptake and the therapeutic efficacy of [123I]CC1 were determined in human breast carcinoma, pancreatic adenocarcinoma, and glioblastoma cells. Tumor uptake and tumor growth inhibition of [123I]CC1 were assessed in mice bearing human cancer xenografts (MDA-MB-231, PSN1, and U87MG). Results: In vitro and in vivo studies showed selective uptake of [123I]CC1 in all models. Significantly reduced clonogenicity, a proxy for tumor growth inhibition by ionizing radiation in vivo, was observed in vitro after treatment with as little as 10 Bq [123I]CC1. Biodistribution at 1 h after intravenous administration showed PSN1 tumor xenograft uptake of 0.9 ± 0.06 percentage injected dose per gram of tissue. Intravenous administration of a relatively low amount of [123I]CC1 (3 MBq) was able to significantly inhibit PSN1 xenograft tumor growth but was less effective in xenografts that expressed less PARP. [123I]CC1 did not cause significant toxicity to normal tissues. Conclusion: Taken together, these results show the potential of [123I]CC1 as a radioligand therapy for PARP-expressing cancers.

Abstract 5038: Evaluation of anti-tumor immunity in response to [177Lu]Lu-PSMA in a mouse model of prostate cancer

[177Lu]Lu-PSMA improves progression-free and overall survival in metastatic castration resistant prostate cancer. However, the role of immune stimulation by molecularly targeted radionuclide therapy (MRT) is poorly understood. The aim of this study was to evaluate the anti-tumor immune response induced by [177Lu]Lu-PSMA. The markers of immunogenic cell death (ICD), translocation of calreticulin (CRT) to the cell membrane, HMGB1 release and ATP release, were evaluated in the RM1 cell line (PSMA-negative murine prostate carcinoma) and its derivative, RM1-PGLS (stably transduced with human PSMA and SFG-EGFp/Luc), using flow cytometry, ELISA and a luminescence detection assay respectively. The in vivo biodistribution of [177Lu]Lu-PSMA in RM1-PGLS tumor-bearing C57BL/6 mice was investigated using microSPECT-CT imaging, and the in vivo efficacy of [177Lu]Lu-PSMA was tested in RM1-PGLS tumor growth inhibition studies. Vaccination/rechallenge experiments were performed to elucidate whether [177Lu]Lu-PSMA elicits ICD in vivo. The Nanostring Pan Cancer Immune Profiling Platform was used to assess changes in the tumor immune microenvironment (TIME) in response to [177Lu]Lu-PSMA. External radiation (EBRT; 137Cs γ-radiation; 6-10 Gy) was used as a comparator treatment in most experiments. We observed a dose-dependent increase in cell surface CRT following [177Lu]Lu-PSMA and EBRT at 24 and 72 h and of HMGB1 release in response to [177Lu]Lu-PSMA and EBRT at 96 and 144 h. At 24 h following [177Lu]Lu-PSMA (60 MBq) there was a significant increase in ATP release compared to untreated samples. Collectively these data indicate [177Lu]Lu-PSMA causes ICD. A high RM1-PGLS tumor:muscle uptake ratio (210 ± 59) was noted in biodistribution experiments confirming highly specific tumor accumulation of [177Lu]Lu-PSMA. In tumor growth inhibition studies the time for tumors to reach a volume of 400 mm3 was delayed in mice treated with [177Lu]Lu-PSMA (60 MBq) compared to no treatment (30 versus 21 days; P<0.01). We showed that a subcutaneous inoculum of [177Lu]Lu-PSMA (60 MBq)-treated RM1-PGLS cells prevents tumor growth in approximately 50% of cases on rechallenge with viable RM1-PGLS cells one week later. This indicates that [177Lu]Lu-PSMA induces ICD in vivo. We observed a significant reduction in most tumor infiltrating lymphocyte (TIL) types at 2 days after in vivo exposure to [177Lu]Lu-PSMA (80 MBq), followed by an increase in TILs by Day 7. The observed pattern is similar to that after EBRT (6 Gy). There was overlap in the top 10 differentially expressed genes (treatment versus no treatment) for the [177Lu]Lu-PSMA and EBRT groups. The gene showing the greatest level of upregulation at day 7 in [177Lu]Lu-PSMA-treated tumors, IDO1, is known to be involved in immune tolerance and radioresistance. In conclusion, [177Lu]Lu-PSMA induces ICD in vitro and in vivo and modulates the TIME.

Citation Format: Gemma Dias, Sarah Able, Irini Skaripa-Koukelli, Rachel Anderson, Gracie Wilson, Katherine A. Vallis. Evaluation of anti-tumor immunity in response to [177Lu]Lu-PSMA in a mouse model of prostate cancer. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5038.

A radioiodinated rucaparib analogue as an Auger electron emitter for cancer therapy

INTRODUCTION

Radioligand therapy (RLT) is an expanding field that has shown great potential in the fight against cancer. Radionuclides that can be carried by selective ligands such as antibodies, peptides, and small molecules targeting cancerous cells have demonstrated a clear improvement in the move towards precision medicine. Poly (ADP-ribose) polymerase (PARP) is a family of enzymes involved in DNA damage repair signalling pathway, with PARP inhibitors olaparib, talazoparib, niraparib, veliparib, and rucaparib having FDA approval for cancer therapy in routine clinical use. Based on our previous work with the radiolabelled PARP inhibitor [18F]rucaparib, we replaced the fluorine-18 moiety, used for PET imaging, with iodine-123, a radionuclide used for SPECT imaging and Auger electron therapy, resulting in 8-[123I]iodo-5-(4-((methylamino)methyl)phenyl)-2,3,4,6-tetrahydro-1H-azepino[5,4,3-cd]indol-1-one, ([123I]GD1), as a potential radiopharmaceutical for RLT.

METHODS

[123I]GD1 was synthesized via copper-mediated radioiodination from a selected boronic esters precursor. In vitro uptake, retention, blocking, and effects on clonogenic survival with [123I]GD1 treatment were tested in a panel of cancer cell lines. Enzymatic inhibition of PARP by GD1 was also tested in a cell-free system. The biodistribution of [123I]GD1 was investigated by SPECT/CT in mice following intravenous administration.

RESULTS

Cell-free enzymatic inhibition and in vitro blocking experiments confirmed a modest ability of GD1 to inhibit PARP-1, IC50 = 239 nM. In vitro uptake of [123I]GD1 in different cell lines was dose dependent, and radiolabelled compound was retained in cells for >2 h. Significantly reduced clonogenic survival was observed in vitro after exposure of cells for 1 h with as low as 50 kBq of [123I]GD1. The biodistribution of [123I]GD1 was further characterized in vivo showing both renal and hepatobiliary clearance pathways with a biphasic blood clearance.

CONCLUSION

We present the development of a new theragnostic agent based on the rucaparib scaffold and its evaluation in in vitro and in vivo models. The data reported show that [123I]GD1 may have potential to be used as a theragnostic agent.

Correlation between molar activity, injection mass and uptake of the PARP targeting radiotracer [18F]olaparib in mouse models of glioma

PURPOSE

Radiopharmaceuticals targeting poly(ADP-ribose) polymerase (PARP) have emerged as promising agents for cancer diagnosis and therapy. PARP enzymes are expressed in both cancerous and normal tissue. Hence, the injected mass, molar activity and potential pharmacological effects are important considerations for the use of radiolabelled PARP inhibitors for diagnostic and radionuclide therapeutic applications. Here, we performed a systematic evaluation by varying the molar activity of [18F]olaparib and the injected mass of [TotalF]olaparib to investigate the effects on tumour and normal tissue uptake in two subcutaneous human glioblastoma xenograft models.

METHODS

[18F]Olaparib uptake was evaluated in the human glioblastoma models: in vitro on U251MG and U87MG cell lines, and in vivo on tumour xenograft-bearing mice, after administration of [TotalF]olaparib (varying injected mass: 0.04-8.0 µg, and molar activity: 1-320 GBq/μmol).

RESULTS

Selective uptake of [18F]olaparib was demonstrated in both models. Tumour uptake was found to be dependent on the injected mass of [TotalF]olaparib (µg) but not the molar activity. An injected mass of 1 μg resulted in the highest tumour uptake (up to 6.9 ± 1.3%ID/g), independent of the molar activity. In comparison, both the lower and higher injected masses of [TotalF]olaparib resulted in lower relative tumour uptake (%ID/g; P < 0.05). Ex vivo analysis of U87MG xenograft sections showed that the heterogeneity in [18F]olaparib intratumoural uptake correlated with PARP1 expression. Substantial upregulation of PARP1-3 expression was observed after administration of [TotalF]olaparib (> 0.5 µg).

CONCLUSION

Our findings show that the injected mass of [TotalF]olaparib has significant effects on tumour uptake. Moderate injected masses of PARP inhibitor-derived radiopharmaceuticals may lead to improved relative tumour uptake and tumour-to-background ratio for cancer diagnosis and radionuclide therapy.

Imaging PARP with [18F]rucaparib in pancreatic cancer models

PURPOSE

Rucaparib, an FDA-approved PARP inhibitor, is used as a single agent in maintenance therapy to provide promising treatment efficacy with an acceptable safety profile in various types of BRCA-mutated cancers. However, not all patients receive the same benefit from rucaparib-maintenance therapy. A predictive biomarker to help with patient selection for rucaparib treatment and predict clinical benefit is therefore warranted. With this aim, we developed [18F]rucaparib, an 18F-labelled isotopologue of rucaparib, and employed it as a PARP-targeting agent for cancer imaging with PET. Here, we report the in vitro and in vivo evaluation of [18F]rucaparib in human pancreatic cancer models.

METHOD

We incorporated the positron-emitting 18F isotope into rucaparib, enabling its use as a PET imaging agent. [18F]rucaparib binds to the DNA damage repair enzyme, PARP, allowing direct visualisation and measurement of PARP in cancerous models before and after PARP inhibition or other genotoxic cancer therapies, providing critical information for cancer diagnosis and therapy. Proof-of-concept evaluations were determined in pancreatic cancer models.

RESULTS

Uptake of [18F]rucaparib was found to be mainly dependent on PARP1 expression. Induction of DNA damage increased PARP expression, thereby increasing uptake of [18F]rucaparib. In vivo studies revealed relatively fast blood clearance of [18F]rucaparib in PSN1 tumour-bearing mice, with a tumour uptake of 5.5 ± 0.5%ID/g (1 h after i.v. administration). In vitro and in vivo studies showed significant reduction of [18F]rucaparib uptake by addition of different PARP inhibitors, indicating PARP-selective binding.

CONCLUSION

Taken together, we demonstrate the potential of [18F]rucaparib as a non-invasive PARP-targeting imaging agent for pancreatic cancers.

Prognostic value of exercise stress echocardiography in patients with known coronary artery disease

Funding Acknowledgements

Type of funding sources: None.

Background

Exercise stress echocardiography (EE) is useful for diagnosis and risk stratification in patients (pts) with suspected coronary artery disease (CAD). Pts with known CAD carry a high risk of events. Our aim was to assess the utility of EE in predicting outcomes in this population.

Methods

Single center retrospective study of consecutive pts with known CAD who performed an EE between 2018 and 2019. The primary endpoint was a composite of admission for acute coronary syndrome (ACS), coronary revascularization and cardiovascular death during the follow-up.

Results

A total of 76 pts were included (mean age 59±9 years; 87% male). Fifty-nine (78%) pts had history of ACS, 51 (67%) of percutaneous coronary intervention (PCI) and 14 (18%) of coronary artery bypass graft. The majority of pts had 2 or more vessel disease (42 pts; 55%).

The main reason for performing EE was new onset of chest pain (38 pts; 50%) followed by functional assessment of coronary stenoses after incomplete revascularization (29 pts; 38%). The majority of pts had a preserved left ventricular ejection fraction (67; 88%). The exam was performed under beta-blocker effect in 35 (46%) pts.

The results of EE were positive for myocardial ischemia in 7 (9%) pts, negative in 37 (49%) pts and inconclusive in 32 (42%) pts. Mean exercise time was 8±3 minutes and mean METs achieved was 9.4±2.6. ST-segment depression fulfilling electrocardiographic criteria for ischemia occurred in 17 (22%) pts. Eleven (14%) pts complained of chest pain during the exam.

During a median follow up of 22 months (IQR 15-26), the primary endpoint occurred in 9 pts (admission for ACS in 5 pts; revascularization for chronic coronary syndrome in 4 pts). No cardiovascular death occurred. The positive predictive value of EE for the primary endpoint was 57.1% and the negative predictive value (NPV) 97.3%.

In a survival analysis, the predictors of the primary endpoint were lower exercise time, lower METs achieved, untreated significant coronary lesions and a positive EE (figure).

After adjustment in a multivariate analysis, a positive EE was an independent predictor of the primary endpoint (HR 4.6, 95%CI: 1.1-16.7, p=.044).

Conclusion

In pts with known CAD, EE had a high NPV and a positive result was an independent predictor of future cardiovascular events.

A left systolic dysfunction study in a group of breast cancer patients and its clinical impact

Funding Acknowledgements

Type of funding sources: None.

Background

 Cancer therapy-related cardiac dysfunction (CTRCD) is one of the major complications being reported in patients with breast cancer (BC) under chemotherapy, in particular with anthracyclines (A) or trastuzumab (T). CTRCD is defined as a reduction of left ventricular ejection fraction (LVEF) &gt;10% to a value &lt;50% or as a relative reduction of global longitudinal strain (GLS) &gt;15%.

Purpose

We aim to evaluate the frequency of CTRCD and its clinical impact on BC patients.

Methods

 Retrospective study of patients with BC treated with A and/or T between Jan 2017 and Dec 2018 who underwent a  transthoracic echocardiography (TTE) before, during, and after chemotherapy. We analysed their baseline characteristics and outcomes based on the type of treatment received, and focusing specially on parameters of ventricular function.

Results

 We included 128 females with median age of 54 ± 11 years-old, treated with A (78; 60.9%), T (14; 10.9%) or A followed by T (36; 28.1%).

At the end of A therapy, there was a significant decrease in LVEF (64,2 ± 5,4% vs 62.6 ± 5,3%, p &lt; 0.05) and in GLS (-20,7 ± 1.9% vs -18.8 ± 2.2%, p &lt; 0.001) compared to baseline. No change in tricuspid annular systolic velocity (S") (p = 0,842) was observed. At 2 years of follow-up, this group of patients had no significant difference in LVEF (64,58 ± 5,58 vs 62,63 ± 6,48, p = 0,053) but maintained a significant lower GLS (-20,84 ± 2,13 vs -18,51± 2,52, p &lt; 0,001) compared to baseline. A significant decrease in S’ (14,36 ± 2,55 vs 13,25 ± 2,26, p &lt; 0,05) was observed.

During T therapy, there was a significant decrease in LVEF (65,04 ± 5,41 vs 59,30 ± 6,21, p &lt; 0,001), in GLS (-21,21 ± 2,75 vs -17,89 ± 2,77, p &lt; 0,001) and in S’ (14,39 ± 3,05 vs 12,19 ± 1,62, p &lt; 0,001) compared to baseline. At the end of T therapy (with or without A), this group of patients maintained a significant decrease in LVEF (65,11 ± 5,65 vs 61,29 ± 6,39, P &lt; 0,001) and in GLS (-21.41%±2,86 vs -19.54%±3,50, p &lt; 0,01). S’ returned to normal values (p = 0,10). At 2 years of follow-up, this group of patients maintained a significant decrease in LVEF (65,00 ± 5,99 vs 61,18 ± 6,30, p &lt; 0,05) but GLS (p = 0,235) returned to normal values. No change in S’ was observed (p =0,379).

During a mean follow-up of 38 months, 35 (27%) patients developed CTRCD with a higher prevalence in patients who took A followed by T (18; 14%), 9 (7%) presented with clinical heart failure, 1 (1%) needed hospitalization, 5 (4%) needed to temporarily suspend treatment and 3 (2%) needed to definitely stop treatment.

Conclusions

 Treatment with A was associated with a decrease in LV systolic function at the end of therapy. A decrease in right ventricular (RV) systolic function was observed at 2 years of follow-up. Treatment with T was associated with a decrease in RV and LV systolic function during therapy. CTRCD occurred in 27%, mainly on patients with both A and T therapy, a frequency within literature data. CTRCD had clinical impact leading to HF and suspension of chemotherapy.

Cancer therapeutics-related cardiac dysfunction: what is the role of cardioprotective medication?

Funding Acknowledgements

Type of funding sources: None.

Introduction

Cancer therapy-related cardiac dysfunction (CTRCD) is one of the major complications being reported in patients with breast cancer (BC) under chemotherapy, in particular with anthracyclines (A) or trastuzumab (T). Guidelines recommend regular left ventricular ejection fraction (LVEF) assessments and CTRCD management with cardioprotective medication (CPM). However, while secondary prevention has already entered clinical practice, primary prevention is still in the research domain.

Purpose

Our aim was to evaluate the role of CPM and the risk of CTRCD in BC patients.

Methods

Retrospective study of BC patients treated with A and/or T between Jan 2017 and Dec 2018 who underwent a transthoracic echocardiography (TTE) before, during, and after chemotherapy. Patients with baseline LVEF &lt;50% were excluded. CTRCD is defined as reduction of EF &gt;10% to a value &lt;50% or as relative reduction of global longitudinal strain (GLS) &gt;15%. As CPM we considered angiotensin-converting enzyme inhibitors (ACEI), angiotensin receptor blocker (ARB) and beta-blockers (BB).

Results

We included 128 patients, all female with median age of 54 ± 11 years-old, treated with A (78; 60.9%), T (14; 10.9%) or A followed by T (36; 28.1%).

At baseline, mean LVEF was 64,7 ± 5,7% and mean GLS was -20,8 ± 2,3.

During a mean follow-up of 38 months, 35 (27%) patients developed CTRCD with a higher prevalence in patients who took A followed by T (18; 14%), 9 (7%) presented with clinical heart failure, 1 (1%) needed hospitalization, 5 (4%) needed to temporarily suspend treatment and 3 (2%) needed to definitely stop treatment. ACEI/ARB therapy was initiated in 12 (34%) and BB therapy was initiated in 10 (29%). Twenty-one (60%) of CTRCD patients recovered. CPM initiation after CTRCD was not associated with a significant higher rate of cardiac function recovery (p = 0,682).

When comparing patients already medicated with CPM before cancer treatment (39; 30,5%) to those naïve of CPM, the first group presented a lower incidence of CTRCD (7% vs 20%) but it was not statistically significant (p = 0,473).

In patients treated with T or A + T, the group of patients treated with CPM before cancer treatment did not present a significantly lower incidence of CTRCD (p = 0,449) compared to patients CPM naïve. Nonetheless, there was a significant higher LVEF in the TTE during T therapy, after chemotherapy and at 2 years of follow-up (P &lt;0,05) in patients treated with CPM before cancer treatment compared to patients CPM naïve.

In patients treated with A (without T) there was no statistically significant difference between the two groups.

Conclusion

 In our study, pre-treatment with CPM was associated with a significant higher LVEF in patients treated with T but no significant association was found with respect to the occurrence of CTRCD. CPM initiation after CTRCD was not associated with a statistically significant cardiac function recovery.

Impact of an inconclusive exercise stress echocardiogram on cardiovascular outcomes

Funding Acknowledgements

Type of funding sources: None.

Background

Exercise stress echocardiography (ESE) is used for the assessment of suspected or known coronary artery disease (CAD); however, a certain percentage of ESE studies are inconclusive. We aim to evaluate the prognostic impact of an inconclusive ESE on cardiovascular outcomes.

Methods

Single-center retrospective study of consecutive patients (pts) who performed an ESE between 2018 and 2019 for diagnosis or stratification of CAD. All pts performed a symptom-limited Bruce protocol. ESE was considered inconclusive when 85% of age-predicted maximum HR was not reached. Primary endpoint was a composite of admission for acute coronary syndrome (ACS), coronary revascularization and cardiovascular death during the follow-up.

Results

A total of 141 pts were included (76% male; mean age 60 ± 9 years). ESE was inconclusive in 51 (36%) pts, positive in 11 (8%) and negative in 79 (56%).

The mean exercise time of pts with inconclusive ESE was 7 ± 2 minutes and 76% had normal functional capacity. Fatigue (25 pts; 49%) and lower extremities pain (11 pts; 22%) were the main reasons for ESE stopping. Five pts (10%) complained of chest pain during exam.

Pts with an inconclusive ESE were more diabetic (inconclusive 43%, positive 9%, negative 13%; p=.001), had more chronic obstructive pulmonary disease (COPD) (14%, 0%, 2.5%; p=.026), performed more frequently the exam under beta blocker (BB) therapy (59%, 27%, 18%; p=.041) and had less ST-segment depression fulfilling electrocardiographic criteria for ischemia (10%, 64%, 27%, p&lt;.001). Their functional capacity was worse than negative ESE pts (p&lt;.001).

During a median follow up of 22 months (IQR 15-27), 13 (9.2%) pts had the primary endpoint, including 5 pts (3.5%) with ACS.

Pts with an inconclusive ESE had a lower incidence of the primary outcome than pts with a positive ESE and a higher incidence of events than pts with negative results (figure).

In multivariate analysis, after adjusting for functional capacity and electrocardiographic criteria for ischemia, an inconclusive ESE was an independent predictor of the primary endpoint (HR 9.7, IC95% 1.1-87,6 p= .042)

Conclusions

The frequency of inconclusive ESE is not negligible (36%). These pts had more diabetes and COPD and performed the exam under BB therapy more frequently, highlighting the importance of proper patient selection. An inconclusive ESE was associated to a higher risk of cardiovascular events compared to negative ESE. Abstract Figure.

Prevalence and clinical impact of latent obstruction in hypertrophic cardiomyopathy

Funding Acknowledgements

Type of funding sources: None.

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is characterized by varying degrees of left ventricular outflow tract obstruction (LVOTobs). We aim to define the prevalence, clinical profile and impact of LVOTobs under physiological exercise in HCM patients (pts).

METHODS

Single center retrospective study of consecutive HCM pts without LVOTobs at rest (resting gradient &lt;30mmHg), referred for exercise stress echocardiogram (ESE) between 2015 and 2019. Significative latent obstruction was defined as a LVOT gradient ≥50 mmHg during exercise or at early recuperation.

RESULTS

A total of 56 pts were included (64% men, mean age 57 ± 11 years, 61% septal HCM). The majority of pts (47; 84%) were in NYHA I functional class, 20 (36%) had history of syncope or pre-syncope (S/pS) and 7 (13%) had an implantable cardioverter defibrillator (ICD). Twelve (21%) pts had systolic anterior motion (SAM) of the mitral valve at rest.

Thirty-five (63%) pts performed ESE under beta-blocker (BB) therapy. Mean exercise time was 8 ± 3 min. During ESE, 2 (4%) pts developed a LVOT gradient between 30 to 50 mmHg and 17 pts (30%) developed a significative LVOTobs gradient (mean 85 ± 18 mmHg).

Pts with significative latent LVOTobs had more previous complaints of S/pS (59% vs 26%, p=.017), a tendency for a higher NYHA functional class (p=.082) and were more frequently on BB therapy (82% vs 18%, p=.043). Mean septum thickness was similar between groups (17 ± 0.7 vs 16 ± 0.6 mm, p=.536). The presence of SAM at rest was more frequent in the significative latent LVOTobs pts (p&lt;.001). No differences were noted in exercise tolerance (p=.526).

During a median follow-up of 43 (IQR 15-53) months, 7 (41%) pts with significative latent LVOTobs had a pre-syncope, 3 (18%) were diagnosed with atrial fibrillation and 2 (12%) had a cardiovascular admission . There was up-titration/initiation of BB therapy in 5 (29%) pts, referral for septal myectomy in 3 (18%) and ICD implantation for primary prevention in 3 (18%) pts. No proper ICD shocks, sustained ventricular arrythmias or deaths occurred.

Comparing significative latent to non LVOTobs pts, the first ones had more ICD implantation (log rank p =.04) and performed a surgical myectomy more frequently (log rank p= .018) during the follow-up.

CONCLUSION

In our study, significative latent LVOTobs was observed in 30% of pts. Its presence can have clinical implications in HCM pts approach and should be suspected in more symptomatic pts and when SAM is present at rest.

Characterization of temporal trends of systolic and diastolic indexes over time in breast cancer patients treated with trastuzumab

Funding Acknowledgements

Type of funding sources: None.

Background

Trastuzumab therapy increases survival in patients (pts) with HER2 positive breast cancer, however, it is associated with a risk of cardiotoxicity (CT). Our aim was to: 1) assess the temporal evolution of systolic and diastolic left and right ventricular indexes during and after T therapy and 2) study the incidence of CT in this group.

Methods

Retrospective study of breast cancer pts treated with T in a single center, during 2017 and 2018, who underwent a comprehensive echocardiographic examination before, quarterly, and after conclusion of T therapy. Pts with a baseline left ventricular ejection fraction (EF) &lt;50% were excluded. CT was defined as a reduction of EF &gt;10% to a value &lt;50% or as a relative reduction of global longitudinal strain (GLS) of more than 15%.

Results

We included 50 women with mean age of 56 ± 10 years and mean body mass index (BMI) of 27 ± 5 kg/m2. Thirty-six (72%) patients underwent anthracycline chemotherapy prior to T and 44 (88%) had performed radiotherapy.

During treatment with T there was an increase of indexed left ventricle end-diastolic volume (38.6 ± 7.8 to 46.5 ± 10.3 ml/m2, p&lt;.001) and a reduction of LVEF (65.1 ± 5.4 to 59.3 ± 6.2%, p &lt; 0.001), GLS (-21.2 ± 2.7 to -17.9 ± 2.8%, p&lt;.001) and right ventricle S’ (14.4 ± 13.1 to 12.2 ± 1.6 cm/s, p&lt;.001) compared to baseline. There was no change in diastolic function parameters.

CT occurred in 23 (46%) pts, the majority based on GLS criteria (18; 78%). Heart failure symptoms were reported in 4 (8%) of these pts (1 in the GLS group and 3 in the EF group) and 3 (6%) pts had to permanently suspend therapy with T due to CT.

Patients with CT had a lower BMI (25 ± 4 vs 29 ± 4 kg/m2), but were otherwise similar to pts without CT. No association was found between pre-treatment with anthracyclines or radiotherapy with the risk of CT.

An echocardiographic revaluation at 2 years from treatment with T revealed a tendency for LVEF improvement (58.7 ± 7.1 to 61.2 ± 6.3%, p=.059) and a significative recovery of GLS (-17.4 ± 3.5 to -19.1 ± 3.3%, p=.026). No significative variations were found on right ventricular systolic function indexes or on diastolic parameters.

During a follow-up of 43 (IQR 32–47) months, 7 (14%) pts had tumor relapse and 1 (2%) died. CT was not associated with the composite endpoint of tumor relapse or death (p = 0.585).

Conclusion

T therapy is associated with a significative reduction on left and right ventricle systolic indexes during treatment. Although left ventricle systolic function tends to normalize over time, this does not happen with the right ventricle. CT induced by T had clinical impact leading to overt heart failure in 8% of pts and treatment discontinuation in 6% of pts.  A lower BMI was associated with CT, which may be taken into account when defining the treatment strategy.

A Model System to Explore the Detection Limits of Antibody-Based Immuno-SPECT Imaging of Exclusively Intranuclear Epitopes

Imaging of intranuclear epitopes using antibodies tagged to cell-penetrating peptides has great potential given its versatility, specificity, and sensitivity. However, this process is technically challenging because of the location of the target. Previous research has demonstrated a variety of intranuclear epitopes that can be targeted with antibody-based radioimmunoconjugates. Here, we developed a controlled-expression model of nucleus-localized green fluorescent protein (GFP) to interrogate the technical limitations of intranuclear SPECT using radioimmunoconjugates, notably the lower target-abundance detection threshold. Methods: We stably transfected the lung adenocarcinoma cell line H1299 with an enhanced GFP (EGFP)-tagged histone 2B (H2B) and generated 4 cell lines expressing increasing levels of GFP. EGFP levels were quantified using Western blot, flow cytometry, and enzyme-linked immunosorbent assay. An anti-GFP antibody (GFP-G1) was modified using dibenzocyclooctyne-N3-based strain-promoted azide-alkyne cycloaddition with the cell-penetrating peptide TAT (GRKKRRQRRRPPQGYG), which also includes a nuclear localization sequence, and the metal ion chelator N3-Bn-diethylenetriamine pentaacetate (DTPA) to allow radiolabeling with 111In. Cell uptake of 111In-GFP-G1-TAT was evaluated across 5 cell clones expressing different levels of H2B-EGFP in vitro. Tumor uptake in xenograft-bearing mice was quantified to determine the smallest amount of target epitope that could be detected using 111In-GFP-G1-TAT. Results: We generated 4 H1299 cell clones expressing different levels of H2B-EGFP (0-1 million copies per cell, including wild-type H1299 cells). GFP-G1 monoclonal antibody was produced and purified in house, and selective binding to H2B-EGFP was confirmed. The affinity (dissociation constant) of GFP-G1 was determined as 9.1 ± 3.0 nM. GFP-G1 was conjugated to TAT and DTPA. 111In-GFP-G1-TAT uptake in H2B-EGFP-expressing cell clones correlated linearly with H2B-EGFP expression (P < 0.001). In vivo xenograft studies demonstrated that 111In-GFP-G1-TAT uptake in tumor tissue correlated linearly with expression of H2B-EGFP (P = 0.004) and suggested a lower target-abundance detection threshold of approximately 240,000 copies per cell. Conclusion: Here, we present a proof-of-concept demonstration that antibody-based imaging of intranuclear targets is capable both of detecting the presence of an epitope of interest with a copy number above 240,000 copies per cell and of determining differences in expression level above this threshold.

Family screening in brugada syndrome patients

Background

Brugada syndrome (BS) is a rare inherited channelopathy associated with sudden cardiac death (SCD) and family screening (FS) of index patients (pts) is recommended. However, data about pts identified through FS is lacking.

Aim

To compare index pts to non-index pts identified through systematic FS.

Methods

Single-center retrospective study of BS pts followed by the Arrhythmology Department. FS was offered to 1st degree relatives of all index pts through primary care services and a once-weekly voluntary open appointment. Genetic counselling was performed when indicated. Index and non-index pts were compared regarding baseline characteristics and events during the follow-up (syncope of probable arrhythmic origin, ventricular tachycardia/ventricular fibrillation (VT/VF) and SCD).

Results

We included 165 pts (61% males, mean age 47±15 years) and 72 (44%) were identified through FS. Non-index pts were diagnosed at a younger age (42±14 vs 51±14 years, p &lt;.001), were more often female (57% vs 25%, p&lt;.001), were diagnosed predominantly through provocative test with ajmaline/flecainide (88% vs 47%, p&lt;.001) and had less documented spontaneous type 1 ECG pattern (17% vs 59%, p&lt;.001). A type 2 pattern was identified in 18 (25%) non-index pts.

Genetic testing was performed in 38 (53%) non-index pts: 6 had a pathogenic SCN5A mutation, 18 a likely pathogenic SCN5A mutation and 12 a mutation of uncertain significance.

At diagnosis, 24 (33%) non-index pts had history of syncope, 3 (4%) had nocturnal agonal respiration and 11 (15%) had palpitations with no differences between both groups (p=.119). Non-index pts were less likely to implant a cardioverterdefibrillator (14% vs 38%, p=.001).

During a median follow-up of 28 (IQR 16–41) months, 10 (6%) pts had an event - 2 (3%) in the non-index group (2 syncope) and 8 (9%) in the index group (1 syncope; 7 VT/VF) - with no significative differences between groups (p=.432). There were nocardiovascular deaths.

Conclusions

FS identified a considerable proportion of BS pts. Non-index pts were younger at the time of the diagnosis and had less spontaneous type 1 pattern. No differences were found in events between index and non-index pts, however, the event rate was low. Systematic FS can identify individuals at risk of SCD earlier, allowing close monitoring and, when indicated, appropriate treatment.

Funding Acknowledgement

Type of funding sources: None.

Gender related differences in brugada syndrome

Background

Brugada syndrome (BS) is a heritable channelopathy with male predominance. Males (M) seem to have a higher risk of arrhythmic events, although, there is limited data regarding gender differences in BS.

Aim

To compare the differences between genders in a Portuguese sample of BS patients (pts).

Methods

Single-center retrospective study of BS pts followed by the Arrhythmology Department. Pts were divided according to gender and compared regarding baseline characteristics and electrocardiographic (ECG) parameters that possibly predict the arrhythmic risk (significative S wave in DI, R wave sign, Tpeak-Tend interval and fragmented QRS). The events during follow-up were syncope of probable arrhythmic origin, ventricular tachycardia/ventricular fibrillation (VT/VF) and sudden cardiac death (SCD).

Results

A total of 165 pts were included; 64 (39%) were female (F) and the mean age at diagnosis was 47±15 years. The diagnosis was made by family screening (FS) in 72 (44%) pts. Sixty-seven pts (41%) had spontaneous type 1 pattern, 59 (36%) had history of syncope and 5 (3%) had history of aborted SCD. A positive genetic test was identified in 41 (25%) pts. Sixty-three (38%) pts were referred for an electrophysiological study (EEF) which was positive in 17 (27%) pts. A cardioverter-defibrillator was implanted in 45 (27%) pts. Females were more often diagnosed by FS (64% vs 31%, p &lt;.001), had less type 1 spontaneous pattern (22% vs 53%, p&lt;.001) and had no atrial fibrillation (0% vs 7%, p=.043). They performed EEF less frequently (22% vs 49%, p&lt;.001) and had less spontaneous pattern during treadmill stress test (8% vs 33%, p=.004).

Regarding ECG parameters, females had shorter QRS interval (104±12 vs 115±18 ms, p&lt;0.001), less frequent aVR sign (3% vs 27%, p&lt;0.001), less significative S wave in DI (31% vs 55%, p=0.004), and a tendency for a shorter Tp-Te interval (80 vs 100 ms, p=0.051). Corrected QT interval was longer in females (396 vs 392ms, p=0.044). During a median follow-up of 28 (IQR 16–41) months, 7 pts had VT/VF (2F, 5M) and 3 had syncope (3M), with no differences between gender (p=0.287). There were no cardiovascular deaths.

Conclusion

In BS, female pts are more often diagnosed by FS and have less spontaneous type 1 pattern. Gender appears to affect basal ECG characteristics in BS, namely in parameters that may predict arrhythmic risk. Further studies are important to clarify the role of gender in prognosis and risk stratification of BS pts.

Funding Acknowledgement

Type of funding sources: None.

Impact of atrial fibrillation and biventricular pacing percentage on long-term outcome in patients with heart failure treated with cardiac resynchronization therapy

Introduction

A history of preoperative atrial fibrillation (AF) has been found to be associated with unfavorable outcomes, higher risks of non-response to cardiac resynchronization therapy (CRT) and loss of biventricular pacing (BivP). We aimed to assess the impact of AF and BivP on long-term outcomes in heart failure patients treated with CRT.

Methods

We retrospectively enrolled 227 patients undergoing CRT implantation between 2013 and 2020 according to the current guidelines. 118 patients were included in our analysis, from whom all data were available. Clinical, electrocardiographic and echocardiographic parameters were evaluated at baseline and 6 months after CRT. Response to CRT was defined as an increase in left ventricular ejection fraction (LVEF) &gt;10%. We considered an effective delivery of BivP &gt;98%. The primary endpoint was the composite endpoint of hospitalization due to HF or death for any cause.

Results

118 patients were included (mean age 69±11 years, 66.1% males, 39.8% ischemic etiology; baseline LVEF was 27,6±6%). Patients were divided into AF (n=42; 35,6%) and sinus rhythm (SR (n=76); 18 patients had permanent AF. AF patients had higher index left atrial volume and left ventricular mass (p&lt;0.001). Mean follow-up time was 43±18 months. BivP percentage was significantly superior in SR than in AF patients (98.1±2.1% vs 94.7±4.5%, p&lt;0.001), with 75% of SR patients having BivP&gt;98% vs 30,3% of AF patients (p&lt;0.001). There were no differences in preoperative parameters between them. The response rate to CRT was higher in SR patients when compared to AF patients (63,2% vs 40,5%, p=0.021). Indeed, the variation of LVEF was higher in SR patients (12±10% vs 7±9%, p=0.012).

During follow-up, there were significant differences between AF and SR patients in the primary endpoint (73,8% vs 42,6%, p&lt;0.001), and mortality for any cause (26,2% vs 9,2% p=0.014; p&lt;0.001). In a multivariate logistic regression analysis pre-procedural AF and BivP (%) were the only independent predictors of primary endpoint (HR 8.949, 95% CI 2.429 – 32.972, p=0.001; HR 0.719, 95% CI 0.526 – 0.982, p=0.038, respectively). Kaplan-Meier curves showed that event survival free was higher in SR patients when compared to AF (69±4 vs 24±3 months, p&lt;0.001)

Conclusion

Pre - procedural AF and BivP are independent predictors of the occurrence of a primary endpoint of hospitalization due to HF or death for any cause in HF patients submitted to CRT.

Funding Acknowledgement

Type of funding sources: None.

Right ventricular dysfunction is a predictor of non-response to cardiac resynchronization therapy

Introduction

Cardiac resynchronization therapy (CRT) has been of great benefit to many heart failure (HF) patients with reduced ejection fraction (EF) and intraventricular conduction delay. However, approximately 30% of patients fail to respond to CRT. We investigated baseline characteristics that might influence response to CRT.

Methods

We retrospectively enrolled 227 patients undergoing CRT implantation between 2013 and 2020 according to the guidelines. 118 patients were included in our analysis, from whom all data were available. Clinical, electrocardiographic and echocardiographic parameters were evaluated at baseline and 6 months after CRT implantation. Response to CRT was defined as an increase in left ventricular ejection fraction (LVEF) &gt;10%. Right ventricular systolic dysfunction (RVSD) was defined as S' velocity &lt;9.5 cm/s or tricuspid anular plane systolic excursion (TAPSE) &lt;17 mm. Chronic kidney disease (CKD) was defined as GFR &lt;60 ml/min/1.73m2.

Results

118 patients were included (mean age 69±11 years, 66.1% males, 39.8% ischemic etiology; 35,6% atrial fibrillation, baseline LVEF 27,6±6%). After 6 months of CRT, 65 patients (55.1%) were considered responders. Responders were more frequently female than non responders (43,1% vs 22,6, p=0.02). Atrial fibrillation and CKD were more prevalent in non responders (47,2% vs 26,2%, p=0.018; 62,3% vs 21,5%, p&lt;0.001, respectively). RVSD was present in 60,4% of non responders vs 16,9% of responders (p&lt;0.001). In responder group, the mean S' velocity was 10,9±2,1 cm/s vs 9,1±2,1 cm/s in non responder group, p&lt;0.001. The mean TAPSE was also higher in responder group (20,3±7,2 mm vs 16,5±4,4 mm, p=0.031). On multivariate analysis only RVSD (OR 7,754; 95% CI 2,968 – 20,282 p&lt;0.001] and CKD (OR 5,434; 95% CI 2,109 – 14,002; p&lt;0.001) were independently associated with non-response to CRT.

Conclusion

From a range of preoperative characteristics, multivariate analysis only identified RVSD and CKD as independent predictors of CRT response, with S' &lt;9,5 cm/s and TAPSE &lt;17 mm associated with non-response to CRT. This study highlights the importance of routine RV assessment in order to improve patient selection and optimize CRT response in heat failure patients.

Funding Acknowledgement

Type of funding sources: None.

QRS narrowing predicts left ventricular reverse remodelling after resynchronization therapy in patients with end-stage heart failure

Introduction

Cardiac resynchronization therapy (CRT) is an established treatment for heart failure (HF) patients, however one-third of the patients fail to benefit from CRT. The relationship between the QRS duration, severity of mechanical dyssynchrony and efficacy of CRT is not completely understood. We determined if QRS duration shortening after CRT implantation was predictive of left ventricular reverse remodelling.

Methods

We retrospectively enrolled 227 patients undergoing CRT implantation between 2013 and 2020 according to the guidelines. 88 patients were included in our analysis, from whom all data were available, and these represent our sample. Clinical, electrocardiographic and echocardiographic parameters were evaluated at baseline and after 6 months of CRT implantation. Response to CRT was defined as a reduction in left ventricular end-diastolic volume (LVEDV) &gt;15%. Linear regression models were used.

Results

88 patients were included (mean age 69±10 years, 62.5% males, 36.4% ischemic etiology). Baseline left ventricular ejection fraction (LVEF) was 27,5±5,8% and LVEDV was 181±69 ml. After 6 months of CRT, 52 patients (59.1%) were considered responders. Baseline LVEDV was superior in responders when compared with non responders (199±85 ml vs 168±53 ml, p=0.038). No significant differences were noted in male gender (p=0.823), ischemic cardiomyopathy (p=0.065), LVEF (p=0.853), atrial fibrillation (p=0.390), left bundle branch block (p=0.950) or biventricular pacing (p=0.154) between them.

QRS duration at baseline was similar between responders and non-responders (165±17 ms vs 163±17 ms, p=0.620). After 6 months of CRT, the reduction of QRS duration in responders was significantly higher than non-responders (p&lt;0.001).

QRS duration was reduced from 165±17 ms to 136±15 ms in responders vs 163±17 ms to 160±17 ms in non-responders, (p&lt;0.001). The change in QRS duration positively correlated with the change in LVEDV (0. 654; p&lt;0.001). Multi-linear regression analysis suggested that QRS duration shortening had a significant effect on LVEDV (y = 14,375 + 1.354 X, R2 0.337, p&lt;0.001)

Conclusion

QRS duration shortening after CRT implantation was predictive of LV reverse remodelling in end-stage heart failure patients. Further prospective studies should be conducted to assess the prognostic value of QRS narrowing in response to CRT.

Funding Acknowledgement

Type of funding sources: None.

Device therapy guided by implantable loop recorders: predictors of bradyarrhythmic events

Background

Implantable loop recorders (ILR) improved diagnostic yield in unexplained syncope patients (pts). Data on possible predictive factors for bradycardia requiring device implantation in these pts is limited. We aim to identify clinical predictors for device implantation due to a significant bradyarrhythmia in patients who underwent ILR insertion for the study of syncopal/presyncopal (S/pS) events.

Methods

Single-center retrospective study of patients who implanted an ILR for the study of unexplained S/pS episodes between 2013 and 2018. The primary endpoint was a documented bradyarrhythmia requiring device implantation during the follow-up.

Results

A total of 251 pts were included. Mean age was 68±15 years and 53% were female. The majority of pts (220; 88%) had normal ejection fraction. Fifty-two (21%) pts had atrial fibrillation (AF). Regarding basal electrocardiographic characteristics, 34 (14%) pts had 1st degree auriculo-ventricular block (AVB), 31 (12%) pts had left bundle branch block (L-BBB), 22 (9%) pts had R-BBB and 13 (5%) pts had bifascicular block.

During a median follow-up of 20 (IQR 9–34) months, 74 (29%) pts required device implantation because of a significant bradyarrhythmia (92% pacemaker, 4% CRT, 4% ICD). Median duration from ILR until device implantation was 5 (IQR 1–10) months. The indications were sick-sinus-syndrome in 47 (64%) pts, advanced AV block in 23 (31%) pts and symptomatic slow AF in 4 (5%) pts.

Patients who required device implantation were older (73±12 vs 66±15 years, p &lt;0.001), had more hypertension (73% vs 59% p=0.048), a higher prevalence of AF (34% vs 15% p=0.001) and a lower glomerular filtration rate (GFR&lt;60 ml/min: 32% vs 21%, p=0.047). They also had more 1st AVB (22% vs 11%, p=0.026) and intraventricular conduction disturbances (38% vs 25%, p=0.025). There was a trend for a higher device implantation in pts with concomitant 1st AVB and left anterior fascicular block (7% vs 2%, p=0.063)

In a logistic regression model, age &gt;75 years (HR: 1.7; 95% CI: 1.1–2.8) and the presence of AF (HR: 1.8; 95% CI: 1.1–3.0) were independent predictors for device implantation.

Conclusion

An older age and the presence of AF were independent predictors for device therapy in pts who implanted an ILR for the study of S/pS. These factors may identify a higher risk group and should be considered in the initial workup of these pts.

Funding Acknowledgement

Type of funding source: None

P1456 Pacemaker and percutaneous aortic valve endocarditis - a complex decision

CASE REPORT

We describe the case of a 64-year-old man who was referred because of a fever. He had history of hypertension, dyslipidemia, atrial fibrillation, chronic obstructive pulmonary disease and a right lung pneumectomy due to epidermoid lung cancer diagnosed twenty-five years ago. He implanted dual-chamber definite pacemaker ten years ago and had a transcatheter aortic valve implantation (TAVI) in the previous year due to severe aortic stenosis and a high surgical risk.

He was hospitalized 2 months ago because of a respiratory infection. Blood cultures were positive for an Enterococcus faecalis. A transthoracic echocardiogram was performed and had no evidence of vegetations.

After one month, he had recurrence of fever and was again admitted. On physical examination he was hemodynamically stable, with signs of peripheral congestion and no heart murmur on cardiac auscultation. Blood cultures were again positive for Enterococcus faecalis. The transesophageal echocardiogram (TEE) showed a biologic aortic valve with thickened leaflets and small nodular structures suggestive of vegetations. There was a small periprosthetic leak and no obstruction or suspected perivalvular abscesses. There was also a small vegetation with 0,45*0,3 cm in the auricular pacemaker lead. A thoraco-abdomino-pelvic computed tomography scan showed no embolic complications. A diagnosis of pacemaker and TAVI endocarditis was made. The patient started directed antibiotic therapy (ceftriaxone and ampicillin).

The case was discussed in Heart Team and because of high surgical risk, medical treatment was decided. The patient completed antibiotic treatment with negative blood cultures and apyrexia. A repeated TEE showed persistence of vegetations, without development of local complications.

It was decided to discharge the patient under palliative suppressive antibiotic treatment with levofloxacin after discussion with the infectious disease doctor. In a follow-up evaluation, he remained clinically stable, without recurrence of fever.

DISCUSSION

As TAVI procedures are performed more frequently, a higher number of late complications are expected. Prosthetic valve endocarditis after TAVI is a complex situation, whose treatment strategy is not well-defined, particularly because these patients are usually of high surgical risk. This case describes a complex clinical picture and highlights the difficulty in decision-making in these situations. Also, it pretends to reinforce the need to discuss in a Heart Team the best treatment options.

P317 Assessment of atrial function in elite soccer players

Introduction

Athlete´s heart is associated with physiological remodelling as a consequence of repetitive cardiac loading. Atrial dilation may occur in athletes, but atrial size is insufficient to provide mechanistic information about the atrium itself and an increase in atrial size is not intrinsically an expression of atrial dysfunction. Two dimensional (2D) LA strain analysis by speckle tracking emerges as a gold standard for evaluation of atrial myocardial function.

Aim

To compare LA function between elite soccer players and sedentary healthy controls through 2D-strain analysis by speckle tracking.

Methods

We included 44 consecutive male professional soccer players and 25 sedentary male healthy controls, matched by age and race. All subjects underwent transthoracic echocardiogram, including evaluation of LA diameter and volume and 2D-strain analysis by speckle tracking. Peak atrial longitudinal strain (PALS) was measured at the end of the reservoir phase and peak atrial contraction strain (PACS) was measured just before the start of the active atrial contractile phase. The average of PALS and PACS was obtained from the 12 LA segments at apical 4 and 2-chamber views. The LA contraction strain index (CSI) (ratio PACS/PALS x100) was also calculated. SPSS 20.0 was used for statistical analysis.

Results

Mean age was similar between athletes and controls (22.3 ± 4.2 vs 25.0 ± 2.4 p = 0.13) as well as body mass index (23.3 ± 5.8 vs 24.6 ± 2.7 Kg/m2, p = 0.24).

Athletes had significantly higher LA volume (29.1 ± 6.9 vs. 21.1 ± 5.5, p &lt; 0.001). No statistical differences were observed in LA diameter between the two groups (18.7 ± 2 vs 18.0 ±1.7, p = 0.163).

Athletes had significantly lower PALS (36.3%±5.8 vs. 44.2%±8.9, p &lt; 0.001), PACS (9.5%±2.8 vs 15.3%±4.8, p &lt; 0.001) and LA CSI (26.3 ± 7.8 vs. 35.0 ± 9.3, p &lt; 0.001) than controls. LA volume was correlated with PALS (p &lt; 0.001 r = 0.99), but not with PACS or CSI (p = 0.089 and p = 0.142, respectively).

Conclusion

This study showed that in top-level athletes LA PALS and PACS are lower and PALS correlates with LA volume, suggesting that LA suffers not only a morphological but also a functional remodelling in response to intensive exercise. This can be mediated by increased LA workload imposed by the increased left ventricular work.

P6579Genetic profile and predictors of positive genetic test in Brugada syndrome

Introduction

Brugada syndrome (BS) is a channelopathy with autosomal dominant transmission, incomplete penetrance and variable expression. There are 18 different gene mutations described in association with this syndrome, however 70% of patients remain without identifiable genetic cause. Genetic testing is appropriated for patients with clinical diagnosis but it is also a very important tool in familiar screening.

Aim

We aim to characterize genetic profile of patients with clinical diagnosis of BS and identify differences between patients with and without causative mutation.

Methods

We included patients followed by the arrhythmology department of our hospital with diagnosis of BS and that have performed genetic test (or patients who were identified through familiar screening and with negative genetic test in the index case). Patients identified through familiar screening with positive genetic test but no spontaneous electrocardiographic pattern, still awaiting pharmacologic provocative test at the time of enrolment – no clinical diagnosis - were excluded. Genetic test was considered positive when we found a pathogenic or probably pathogenic mutation. Mutations in PKP, SLMAP, CACNA, CACNB, SCN10A and CLASP genes considered of uncertain clinical relevance were not included as positive genetic test. We analysed differences between subset of patients with and without causative mutation regarding clinical and electrocardiographic variables. We performed multivariate analysis to find predictors of positive genetic test.

Results

From our 173 patients, 140 met the inclusion criteria and none exclusion criteria so they were enrolled. Patients were 61% male with mean age of 50±15 years old. Mean follow-up was 26±28 months; 24,4% of index cases were positive for causative mutation, 6,8% patients with pathogenic mutation in SCN5A gene and 17,6% with probably pathogenic mutation in SCN5A.

We haven't found significant differences between the 2 groups (negative and positive genetic test) in any clinical variable included. Regarding electrocardiographic variables, patients in whom a mutation was identified had longer PR interval (192±36 vs 170±28, p=0.001), longer QRS (121±19 VS 111±18 p=0.017), particularly when QRS>110ms (p=0,002), and longer QT (398±25 VS 370±45 p=0.015) In multivariate analysis, PR interval (p=0.032) and QRS>110ms (p=0,041) were independent predictors for positive genetic test.

Conclusion

In our BS population, there were no clinical differences between patients with and without causative mutation, also concerning events rate. Patients with positive genetic test have significantly longer PR interval and QRS>110ms than in patients with genetic test negative. Those results can be interpreted in relation to sodium channel disfunction in patients with SCN5A mutation.

PP145. Hypertensive disorders of pregnancy: A two year study (2008-2009)

INTRODUCTION

The hypertensive disorders of pregnancy are a leading cause of maternal mortality and morbidity. According to the group studies of NHPBEB 2000 four entities are defined: Chronic Hypertension (CH) previous to pregnancy, Gestational Hypertension (GH), Preeclampsia/Eclampsia (PE/E) and superimposed Preeclampisa/Eclampsia in Chronic Hypertension (PE/E CH). All this entities have different outcomes and require adequate follow-up and specific attitude.

OBJECTIVES

Review all cases of hypertensive disorders in a two-year period, its incidences, and related maternal and fetal complications.

METHODS

In a retrospective study, from January 2008 to December 2009, all files related with hypertensive disorders, seen in our department, were reviewed. The statistic analysis was based on Excel 2007.

RESULTS

The global incidence of hypertensive disorders was 3.8% (309 cases), with each entity with an incidence of: 40% in CH, 40% GH, 25% PE/E and 7% PE/E CH. In terms of demographic characteristics the majority of the population were caucasian (46%) and black (40%), the mean age was of 31years (minimum of 12-maximum of 47), and mainly previous Chronic Hypertension and endocrinologic disorders as co-morbidities (Diabetes Mellitus, obesity and thyroid pathology). The fetal/maternal complications were mainly preterm delivery (26.2%), with a low percentage of Abruptio Placentae (1%). Maternal complications were analysed in terms of ICU admissions of 7%, cardiovascular/renal disorders of 1% and maternal bleeding 1%. No maternal death was described. Fetal outcomes were also studied, specifically in terms of birth weight, with an average of 2794 (500-5480g), apgar index in 1st and 5th minute below seven in respectively, 14% and 3.5%.

CONCLUSION

The incidence of maternal complications in our analysis was lower than described in literature. The incidence of preterm delivery was similar to that reported in other studies, mostly due to late pre-terms (>32w).

PP100. Pre-eclampsia: Risk factors and outcomes - A two-year study

INTRODUCTION

Pre-eclampsia (PE) is a hypertensive disorder responsible for major morbidity and mortality in both mother and fetus. There are some risk factors associated with this entity, but it remains very difficult to predict.

OBJECTIVES

Study the incidence of PE and the related risk factors, as well as the maternal and fetal outcome.

METHODS

We reviewed the clinical records of pregnant women admitted to Prof. Fernando Fonseca's Hospital from January 2008 to December 2009, with the diagnosis of pre-eclampsia. The statistic analysis was based on Excel 2007.

RESULTS

There were 90 cases of PE, among the 308 hypertensive disorders reviewed, with an incidence of 1,1% in overall population of pregnant women. Risk factors with higher association were Chronic Hypertension before pregnancy (24,4%), maternal age above 35 years old (16,67%), maternal age under 20 years old (14,44%), and previous episode of pre-eclampsia (8,89%). Major maternal complications that determined Intensive Care Unit admission were recorded in 17 cases (18,89%), with 3 HELLP syndromes (Hemolysis, elevated liver enzymes, and low platelets)(3,33%). No maternal death was recorded. Preterm delivery (PTD) was seen in 61,1%, 32% before 34weeks and 6,67% before 28weeks. There were 19 cases of 1st minute Apgar Index below 7 and 5 cases of 5th minute Apgar Index below 7. There was one in utero death and two interruptions of pregnancy below 24 weeks due to serious PE. Three twin pregnancies.

CONCLUSIONS

PE is a form of hypertensive pregnancy disorder, with a risk of recurrence in subsequent pregnancies. It has a catastrophic potential, mainly associated to PTD, and also with significant morbidity to the pregnant women, reflected in the incidence of admissions to ICU, HELLP syndrome and end-organ failure. In our study we confirmed the adverse outcomes related to this entity, and the risk factors associated.

PP099. Chronic hypertension: follow-up of chronic hypertension pregnant women in 2008-2009

INTRODUCTION

Chronic Hypertension (CH) is one of the most prevalent diseases in the world. Because women are getting pregnant in late ages, the incidence of Chronic Hypertension in pregnancy is raising (2-3%). As a long term disease in its essential form, with low repercussion in target-organs at reproductive age, the medical complications related to CH are not the main concern of the pregnant women. However, it influences the pregnancy and may result in serious maternal-fetal complications, especially if a preeclampsia/eclampsia superimposes to pregnancy. The complications may be manifested as placental abruption, acute renal failure, cardiac decompensation, and cerebral accidents in the mother and of growth restriction and unexplained mid-trimester fetal death. The main goal in the follow-up of this pregnant women is to achieve controlled levels of blood pressure (Systolic - 110-140mmHg, Diastolic - 80-90mmHg) with anti-hypertensive drugs, and evaluate and early diagnose the most serious complication, preeclampsia/eclampsia(PE/E).

OBJECTIVES

Review the cases of Chronic Hypertension followed in our institution in 2008-2009, with the analysis of population, anti-hypertensive drugs required to control HTA, fetal complications (growth restriction, preterm delivery and fetal death) and maternal/fetal complications (PE/E, Abruption placentae, Renal and Cardiac acute insufficiency, and cerebral accidents).

METHODS

In a retrospective study, from January 2008 to December 2009, were analysed all files related with Chronic Hypertension followed in the obstetric department of Prof. Fernando Fonseca's Hospital. The statistic analysis was based on Excel 2007.

RESULTS

The incidence of Chronic Hypertension was 40% of all hypertensive disorders in this period and of 1,5% in overall pregnant population. The maternal mean age of this group was 33,8 years (16;44) being the most prevalent pre-existing co-morbidities the endocrinologic disorders (obesity, Diabetes and thyroid pathology). 38% were previous medicated with anti-hypertensive drugs, the majority of them needing only one drug to control blood pressure (BP) (64%). During the pregnancy follow up, 78% were medicated with one or more anti-hypertensive drugs, requiring only one drug to control BP in the majority of cases 66%. In terms of fetal complications 3 cases of growth restriction were signed (2%), preterm delivery in 26 cases (21%) and 2 interruptions of pregnancy in the second trimester before 24 weeks because of maternal complications (2%). There was one case of Abruption Placentae (1%). In terms of maternal complications there were 5 ICU internments (4%), and one situation of acute cardiac disfunction (1%). The CH was complicated by PE/E in 22 cases (18%).

CONCLUSION

Chronic Hypertension is a prevalent disease, with an elevated incidence in pregnancy, and potential major fetal-maternal complications, obliging medical professionals to a straight and careful follow-up to control BP levels and early diagnose the adversely outcomes.

A pilot study of common health problems in smallholder pigs in Angónia and Boane districts, Mozambique

Apilot survey was conducted in 2 districts in Mozambique to determine the most important health problems facing smallholder pig producers. While African swine fever is the most serious disease that affects pigs at all levels of production in Mozambique, it is likely that productivity is reduced by the presence of mange and gastrointestinal parasites, while in traditional systems the conditions are favourable for the development of porcine cysticercosis caused by the pork tapeworm Taenia solium, which poses a health risk to communities. Results of the pilot survey confirmed that, with the exception of African swine fever, ecto- and endoparasites are probably the most important health risks for producers. Porcine cysticercosis is more prevalent among pigs in traditional, free-ranging systems, while mange becomes a serious factor when pigs are permanently confined.

Permanent genetic resources added to Molecular Ecology Resources Database 1 December 2010-31 January 2011

This article documents the addition of 238 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Alytes dickhilleni, Arapaima gigas, Austropotamobius italicus, Blumeria graminis f. sp. tritici, Cobitis lutheri, Dendroctonus ponderosae, Glossina morsitans morsitans, Haplophilus subterraneus, Kirengeshoma palmata, Lysimachia japonica, Macrolophus pygmaeus, Microtus cabrerae, Mytilus galloprovincialis, Pallisentis (Neosentis) celatus, Pulmonaria officinalis, Salminus franciscanus, Thais chocolata and Zootoca vivipara. These loci were cross-tested on the following species: Acanthina monodon, Alytes cisternasii, Alytes maurus, Alytes muletensis, Alytes obstetricans almogavarii, Alytes obstetricans boscai, Alytes obstetricans obstetricans, Alytes obstetricans pertinax, Cambarellus montezumae, Cambarellus zempoalensis, Chorus giganteus, Cobitis tetralineata, Glossina fuscipes fuscipes, Glossina pallidipes, Lysimachia japonica var. japonica, Lysimachia japonica var. minutissima, Orconectes virilis, Pacifastacus leniusculus, Procambarus clarkii, Salminus brasiliensis and Salminus hilarii.

High airborne PM2.5 chlorine concentrations link to diabetes surge in Portugal

Since 1995 airborne particles have been sampled near Lisbon and analysed by PIXE at ITN. On the Summer of 2004 extremely high concentrations of 14 microg/m(3) of chlorine in PM2.5 were determined in a week average sample. Later in 2004 and in 2005 similar events occurred. A 12 year database of PIXE data on airborne elemental concentrations (1995 to 2006) compiled on 2007 was then analysed for PM2.5 chlorine concentrations above 1 microg/m(3), and showed that the number of this type of events per year is increasing since 1995 up until the present. A quest for time coincident abnormal health data reports was carried out and revealed a 30% raise in diabetes mellitus incidence from 2003 to 2004 followed by a 20% raise from 2004 to 2005. After a first short publication at the XIth Int. PIXE Conference in 2007 (Reis et al., 2007a) the problem remained live. Taking into account new insights into the problem, recently published data, and biomonitoring data that were previously not considered, it was possible to establish a highly probable link between the abnormally high values of PM2.5 chlorine measured in the Lisbon area and the surge in diabetes mellitus incidence in Portugal in 2004 and 2005. Data, reasoning, possible mechanisms and conclusions regarding this link are reported in the present paper.

The false and the true bifid condyles

The bifid mandibular condyle has been described as a condition of unknown aetiology and uncertain pathogenesis. Many see it as the product of accidental trauma or forceps delivery, with the two heads occurring one behind the other in the sagittal plane. In bioanthropological literature, "bifid condyle" often describes pitting in the sagittal plane, dividing the condyle mediolaterally. We examined 38 male and 16 female pre-European-contact Pacific islanders' adult mandibles, and 24 male and 29 female modern Indian mandibles, recording frequency, prominence and position of any condylar groove in both coronal and sagittal planes. We report the tenth known case of a bilaterally-bifid condyle. A groove was found almost twice as likely to occur on the left condyle of the Indians than of the Pacific Islanders, but equally likely to occur on the right side of both groups. That same finding applied to males and females. In order to avoid terminological ambiguity, we suggest that the term "bifid condyle" should be reserved for describing multiple condyles in the sagittal plane only - the true bifid condyle. An hypothesis is offered for the occurrence of the groove in the sagittal plane.

Helicobacter pylori in dyspeptic children and adults: endoscopic, bacteriologic and histologic correlations

Using different bacteriological (urease test, Gram staining and culture) and histological (Steiner staining and modified Giemsa staining) techniques, we searched for the presence of Helicobacter pylori in the gastric antrum of 200 dyspeptic Brazilian patients (106 females and 94 males aged 19 days to 81 years). The presence of bacteria was then correlated with the endoscopic and histological findings. H. pylori was present in 59.5% of the population studied. In Brazil, colonization occurs early, involving 37% of the dyspeptic population by 20 years of age. The presence of H. pylori in the gastric antrum was strongly associated with duodenal ulcer (P < 0.001) and a normal endoscopic examination did not exclude the possibility of colonization of the gastric antrum by H. pylori. The most sensitive test was the preformed urease test (89%). We conclude that more than one diagnostic method should preferably be used for the detection of H. pylori and that the presence of H. pylori is closely correlated with active chronic gastritis (P < 0.001).