Interrelation between baseline plaque characteristics and changes in coronary atherosclerosis with the PCSK9-inhibitor alirocumab: insights from the PACMAN-AMI randomized trial

Background

Patients with acute myocardial infarction (AMI) frequently experience recurrent atherothrombotic events, largely attributable to non-culprit lesions with high-risk characteristics. Statins can halt the progression of coronary atherosclerosis, and addition of protein convertase subtilisin/kexin type 9-inhibitors (PCSK9i) results in incremental low-density lipoprotein cholesterol (LDL-C) lowering and atheroma regression.

Purpose

We sought to examine the interrelation between baseline imaging characteristics, on-treatment LDL-C levels, and changes in coronary atherosclerosis as assessed by serial, multi-modality intracoronary imaging in patients with AMI.

Methods

This is a post hoc analysis from the PACMAN-AMI randomized trial. Patients were randomly allocated to biweekly alirocumab 150 mg vs. placebo on top of high-intensity statin initiated within 24h of presentation with AMI, and underwent serial imaging of the two non-infarct-related arteries at baseline and after 52 weeks. The primary endpoint was percent atheroma volume (PAV) by intravascular ultrasound (IVUS). Powered secondary endpoints were maximal lipid core burden index (maxLCBI4mm) by near-infrared spectroscopy (NIRS) and minimum fibrous cap thickness (FCTmin) by optical coherence tomography (OCT).

Results

Of 300 randomized patients (mean age 58.5±9.8 years, 18.7% women, baseline LDL-C 3.94±0.87 mmol/L), IVUS was serially performed in 265 patients (537 arteries). LDL-C levels decreased to 1.92±0.79 mmol/L with placebo and 0.61±0.61 mmol/L with alirocumab (p<0.001). Compared with placebo (statin alone), alirocumab added to statin resulted in greater PAV reduction (−2.13% vs. −0.92%; p<0.001), greater maxLCBI4mm reduction (−79.42 vs. −37.60; p=0.006), and greater increase in FCTmin (62.67 vs. 33.19 μm; p=0.001). Changes in PAV and maxLCBI4mm were inversely related to on-treatment LDL-C levels, and change in FCTmin was positively related to on-treatment LDL-C levels (Figure 1). Across all patients, we found significant, inverse relationships between change in PAV and baseline PAV [slope: −0.072 (95% CI −0.101 to −0.042); p<0.001], between change in maxLCBI4mm and baseline maxLCBI4mm [slope: −0.437 (95% CI −0.505 to −0.369); p<0.001], and between change in FCTmin and baseline FCTmin [slope: −0.436 (95% CI −0.541 to −0.332); p<0.001]; these findings indicate greater PAV and maxLCBI4mm regression in lesions with greater PAV and LCBI4mm at baseline, and greater fibrous cap thickening in lesions with thinner fibrous caps at baseline.

Conclusion

In this study of intensive LDL-C lowering treatment initiated in the acute AMI setting, more favorable plaque changes were observed in patients with lower on-treatment LDL-C levels and in lesions with more adverse baseline plaque characteristics. Whether AMI patients with high-risk plaque features might derive greater clinical benefit from early initiation of intensive LDL-C-lowering therapies requires further investigation.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Sanofi, Regeneron

Plasma eicosanoid profiling in the course of proprotein convertase subtilisin-kexin type 9 inhibition: insights from a metabolomic analysis

Background

Treatment with monoclonal antibodies targeting circulating proprotein convertase subtilisin-kexin type 9 (PCSK9) was found to reduce all-cause mortality in addition to cardiovascular events, suggesting pleiotropic effects. Eicosanoids are bioactive metabolites involved in cardiovascular disease and have not yet been studied in the course of PCSK9 inhibition.

Methods

In this prospective translational single-center study, plasma samples were collected from 64 patients before and after initiation of PCSK9 inhibitor treatment. Metabolomic analyses were performed using liquid chromatography coupled to high-resolution mass spectrometry.

Results

A total of 62 bioactive eicosanoids were detected. Among the metabolites, four were significantly decreased by PCSK9 inhibition after one month and remained stable after 6 months (figure): arachidonic acid (p=0.003), 12,13-DiHOME (p<0.001), 9-HpODE_9.91 (p=0.007) and HpODE_7.71 (p=0.011). Phospholipase A2 levels were reduced by 40% after 1 month (p=0.003) and by additional 50% after 6 months of treatment (p=0.015), but did not correlate with eicosanoids (p=0.057). The change in arachidonic acid levels resulted in a significant increase in the ratio of omega-3 to omega-6 polyunsaturated fatty acids (p=0.002).

Conclusion

PCSK9 inhibition leads to significant changes in the eicosanoid profile already after one month, in particular to a downregulation of arachidonic acid. This discovery complements the presumed pleiotropic effects of PCSK9 inhibition and may provide additional benefit in the treatment of atherosclerotic disease.

Funding Acknowledgement

Type of funding sources: None.

Increased symmetric dimethyl-arginine is a predictor factor of decreased platelet reactivity and increased bleeding risk in patients with acute coronary syndrome

Background

One of the promising biomarkers in CVD are asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA), which are products of L-arginine methylation and are both involved in endothelial dysfunction. ADMA, SDMA and L-homoarginine, have emerged as biomarkers linked to cardiovascular outcomes [1].

Purpose

To investigate the association of SDMA with platelet reactivity and bleeding risk in patients with acute coronary syndrome (ACS) treated with potent P2Y12 inhibitors prasugrel and ticagrelor.

Methods

Our prospective observational study enrolled 292 patients with ACS undergoing percuteneus coronary intervention [2]. Plasma concentrations of SDMA were measured during the hospitalization for ACS. Impedance aggregometry was used. The primary study endpoint was the concentration of metabolites and platelet reactivity. The primary clinical outcome endpoint was the incidence of Thrombolysis in Myocardial Infarction (TIMI) bleeding events (major, minor and minimal). The efficacy endpoint was the composite of major adverse cardiac events (MACE: stent thrombosis, myocardial infarction, stroke and cardiac death).

Results

There was an inverse correlation between SDMA serum levels and platelet reactivity (r=−0.25; p<0.000). The ADP+PGE1-induced platelet reactivity was 33% lower among patients with the highest SDMA quartile (4th) as compared to those with the 1–3rd SDMA quartile (8 [0–29] vs 12 [0–126] U; p<0.001). The AA-induced platelet reactivity was 56% lower among patients with the highest SDMA quartile (4th) as compared to those with the 1–3rd SDMA quartile (4 [0–48] vs 9 [0–133]; p<0.001). In a multivariate model, the highest SDMA (4th) quartile was found to be an independent predictor of the lowest ADP+PGE1 and AA induced platelet aggregation (OR: 2.666, 95% CI [1.184–5.999], p=0.018).

Conclusions

Our study shows that high plasma concentration of SDMA, but not ADMA, is independently associated with low platelet reactivity to ADP and AA and is associated with major and minor bleeding events in patients with ACS on potent antiplatelet therapies. Therefore, SDMA might have a potential to be further evaluated as a blood biomarker for individualization of duration and potency of antiplatelet therapies in an ACS population at high risk of bleeding complications.

Acknowledgment

I-COMET research team

Funding Acknowledgement

Type of funding sources: None. Figure 1Table 1

High concentrations of plasma trimethylamine-n-oxide is associated with long-term cardiovascular mortality in patients with acute coronary syndrome

Background

Acute coronary syndrome (ACS) remains a leading cause of mortality worldwide [1]. Patients who experienced ACS are at high risk of future cardiovascular events and death [2–4]. Identification of reliable predictive tools could potentially improve the risk stratification [5]. Numerous studies revealed that intestinal microbial organisms (microbiota) and its metabolites, as TMAO (trimethylamine-N-oxide) may play a pathogenic role in a cardiovascular disease (CVD) and ACS [6]. Elevated concentration of circulating TMAO has been associated with increased risk of CVD and major adverse cardiac events (MACE), including myocardial infarction (MI), stroke, major bleeding and all-cause mortality [7].

Purpose

To investigate the association of liver metabolite TMAO with cardiovascular disease (CV)-related and all-cause mortality in patients with acute coronary syndrome (ACS) who underwent percutaneous coronary intervention.

Methods

Our prospective observational study enrolled 292 patients with ACS. Plasma concentrations of TMAO were measured during the hospitalization for ACS. Observation period lasted 7 years in the median. Adjusted Cox-regression analysis was used for prediction of mortality.

Results

ROC curve analysis revealed that increasing concentrations of TMAO levels assessed at the time point of ACS significantly predicted the risk of CV mortality (c-index=0.78, p<0.001). The cut-off value of >4 μmol/L, labeled as high TMAO level (23% of study population), provided the greatest sum of sensitivity (85%) and specificity (80%) for the prediction of CV mortality and was associated with a positive predictive value of 16% and a negative predictive value of 99%. A multivariate Cox regression model revealed that high TMAO level was a strong and independent predictor of CV death (HR=11.62, 95% CI: 2.26–59.67; p=0.003). High TMAO levels as compared with low TMAO levels were associated with the highest risk of CV death in a subpopulation of patients with diabetes mellitus (27.3% vs 2.6%; p=0.004). Although increasing TMAO levels were also significantly associated with all-cause mortality, their estimates for diagnostic accuracy were low.

Conclusions

High TMAO level is a strong and independent predictor of long-term CV mortality among patients presenting with ACS. TMAO concentration of 4 μmol/L may be a cut-off value for prognosis of ACS patients.

Funding Acknowledgement

Type of funding sources: None. Figure 1. Kaplan-Meier curvesTable 1

Cerebral protection in TAVR – can we do without? Impact on stroke rate, length of hospital stay and 12-month mortality

 

Stroke associated with transcatheter aortic valve replacement (TAVR) is a potentially devastating complication. Until recently, the Sentinel™ Cerebral Protection System (CPS; Boston Scientific) has been the only commercially available device for mechanical prevention of TAVR-related stroke. However, its effectiveness is still undetermined.

Methods

Between January 2019 and August 2020 consecutive patients were randomly assigned to TAVR with or without Sentinel™ in a 1:1 fashion. We defined as primary endpoint clinically detectable cerebrovascular events within 72 hours after TAVR, and as secondary endpoints LOS and 12-month mortality. Logistic and linear regression analyses were used to assess associations of Sentinel™ use with endpoints.

Results

Of 411 patients (80±7 y/o, 47.4% female, EuroSCORE II 6.3±5.9%), Sentinel™ was used in 213 (51.8%), with both filters correctly deployed in 189 (46.0%). 20 (4.9%) cerebrovascular events were recorded, 10 (2.4%) of which were disabling strokes. Sentinel™ reduced cerebrovascular events in univariate analysis by 71% (OR 0.29, 95% CI 0.11–0.82; p=0.02) and after multivariate adjustment by 75% (adj. OR 0.25; 95% CI 0.08–0.80; p=0.02). Sentinel™ use was also significantly associated with shorter LOS (8.4±9.6 versus 6.7±6.1 days; p=0.03) and lower 12-month all-cause mortality (15.7% versus 7.5%, p=0.01).

Conclusions

In the present prospective all-comers TAVR cohort, Sentinel™ significantly 1) reduced cerebrovascular events, 2) shortened LOS, and 3) improved 12-month survival. These data promote the use of a CPS when implanting TAVR valves.

Funding Acknowledgement

Type of funding sources: None.

Adaptive development of concomitant secondary mitral and tricuspid regurgitation after TAVR

Background

Concomitant secondary atrioventricular regurgitation is frequent in patients with severe aortic stenosis scheduled fortranscatheter aortic valve replacement (TAVR). The future implications of leaving associated valve lesions untreated after TAVR remain unknown. Aim of the present study wasto characterize the evolution of concomitant secondary atrioventricular regurgitations and to evaluate their impact on long-term prognosis.

Methods

We prospectively enrolled 429 consecutive TAVR patients. All patients underwent comprehensive clinical, laboratory, and echocardiographic assessments prior to TAVR, at discharge, and yearly thereafter. All-cause mortality was chosen as primary study endpoint.

Results

At baseline, severe concomitant secondary mitral regurgitation (sMR) was present in 54 (13%) and severe concomitant secondary tricuspid regurgitation (sTR) in 75 patients (17%). After TAVR 59% of patients with severe sMR at baseline experienced sMR regression, whereas analogously sTR regressed in 43% of patients with severe sTR at baseline. Persistence of sTR and sMR were associated with excess mortality after adjustment for our bootstrap-selected confounder model with an adjusted HR of 2.44 (95% CI 1.15–5.20, P=0.021) for sMR and of 2.09 (95% CI 1.20–3.66, P=0.01) for sTR (Figure 1). Furthermore patients showing regression of atrioventricular regurgitation exhibited survival rates indistinguishable to those seen in patients without concomitant atrioventricular regurgitation (sMR: P=0.83; sTR: P=0.74)

Conclusion

Concomitant secondary atrioventricular regurgitation in patients with severe AS is a highly dynamic process with up to half of all patients showing regression of associated valvular regurgitation after TAVR and subsequent favorable post-interventional outcome. Persistent atrioventricular regurgitation is a major determinant of TAVR futility and proposes a window of early sequel intervention.

Funding Acknowledgement

Type of funding source: None

The role of asymmetric dimethylarginine (ADMA) in the follow-up of patients with precapillary pulmonary hypertension (PH)

Introduction

Asymmetric dimethylarginine (ADMA) interferes with L-arginine in the production of nitric oxide, a key mediator of endothelial cell function. ADMA is elevated in pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) and is associated with unfavorable outcomes.

Aim

To assess the role of ADMA to monitor disease progression of PH patients treated with PAH-specific therapy.

Methods

ADMA was measured by competitive ELISA at baseline (BL) and follow-up (FU). Risk assessment including a clinical assessment, echocardiography, 6-minute walking test, NT-pro-BNP and hemodynamic assessment by right heart catheterization was performed accordingly. Risk was calculated according to the ESC/ERS 2015 guidelines by the SPHAR method.

Results

ADMA samples were collected from 113 patients treated at our institution between 2012 and 2019. 89 (79%) patients had PAH, 15 (13%) were diagnosed with CTEPH and 9 (8%) with group 3 – PH associated with lung disease. 69% were females. 15 (13.3%) patients had a low risk at baseline, 96 (85%) intermediate risk and 2 (1.8%) were high risk patients. 75% received oral medications, 31% received subcutaneous treprostinil. Median baseline ADMA was 0.738umol/l. At BL no significant difference of ADMA plasma levels was found among the different PH types (p=0.063), or between different risk categories (p=0.531).

Change in ADMA plasma levels correlated with change in risk (p=0.002, rs 0.291) and with change in mixed venous saturation (p=0.034, rs −0.205). Change in ADMA plasma levels also correlated with risk at FU (p=0.011, rs 0.240).

Patients categorized as low risk at FU had a median ADMA plasma level decrease of 22%, compared with −3 to 0% ADMA plasma level change in patients with moderate to high risk at FU (p=0.04). Patients who improved their risk category had a median decrease of ADMA plasma level of 23% vs. 2.3% in patients who did not improve (p=0.011). Decrease of ADMA plasma levels was a weak but significant discriminator for improvement of risk in ROC analysis (p=0.032, AUC 0.374).

Conclusion

ADMA plasma levels paralleled the hemodynamic and clinical benefit of PAH-specific treatments in patients with precapillary PH. ADMA could be used as a biomarker for monitoring treatment effects in precapillary PH.

Funding Acknowledgement

Type of funding source: None

P1739 Diameter of the pulmonary artery in relation to the ascending aorta: a promising parameter for the diagnosis of pulmonary hypertension

Background

Pulmonary hypertension (PH) is a disease with significant morbidity and mortality. The first imaging modality in the diagnostic algorithm is transthoracic echocardiography (TTE). Despite significant technological advances in recent years, there are still patients with PH who are missed by TTE. The pulmonary artery to ascending aorta ratio (PA/Ao-R) has been evaluated in cardiac magnetic resonance (CMR) and computed tomography (CT) studies. The ratio was able to detect patients with PH, it correlated with hemodynamics, and it was predictive for mortality. We sought to evaluate the diagnostic accuracy of PA/Ao-R measured by TTE in the detection of PH.

Methods

We evaluated consecutive patients who received quasi-simultaneous transthoracic echocardiography and right heart catheterization (RHC) for evaluation of pulmonary hypertension between July 2015 and July 2016.

Results

A total of 84 patients fulfilled the inclusion criteria, 47 were female, mean age was 65 years. Median PA/Ao-R was 0.8 (Q1;Q3 0.69;0.94). Seventy patients had PH (median mean pulmonary artery pressure (mPAP) was 35.5 mmHg, Q1;Q3 27;47). The area under the curve for the diagnosis of PH via PA/Ao-R was 0.853. A cut-off of 1 was chosen for further analysis. Sensitivity for the diagnosis of PH was 100%, specificity was 23%. PA/Ao-R correlated with mPAP (r = 0.65, p < 0.001), and pulmonary vascular resistance (r = 0.68, p < 0.001). In the subgroup of patients with PH, those patients with a PA/Ao-R of ≥1 had significantly (p < 0.001) higher pulmonary pressures than those below, with a mean mPAP of 53 mmHg as compared to 38.5 mmHg.

Conclusion

PA/Ao-R correlates with mPAP. A ratio of ≥1 should prompt suspicion for the presence of PH. PA/Ao-R should be reported in every patient who is evaluated for PH.

The ESC ACCA EAPCI EORP acute coronary syndrome ST-elevation myocardial infarction registry

Aims 

The Acute Cardiac Care Association (ACCA)–European Association of Percutaneous Coronary Intervention (EAPCI) Registry on ST-elevation myocardial infarction (STEMI) of the EurObservational programme (EORP) of the European Society of Cardiology (ESC) registry aimed to determine the current state of the use of reperfusion therapy in ESC member and ESC affiliated countries and the adherence to ESC STEMI guidelines in patients with STEMI.

Methods and results 

Between 1 January 2015 and 31 March 2018, a total of 11 462 patients admitted with an initial diagnosis of STEMI according to the 2012 ESC STEMI guidelines were enrolled. Individual patient data were collected across 196 centres and 29 countries. Among the centres, there were 136 percutaneous coronary intervention centres and 91 with cardiac surgery on-site. The majority of centres (129/196) were part of a STEMI network. The main objective of this study was to describe the demographic, clinical, and angiographic characteristics of patients with STEMI. Other objectives include to assess management patterns and in particular the current use of reperfusion therapies and to evaluate how recommendations of most recent STEMI European guidelines regarding reperfusion therapies and adjunctive pharmacological and non-pharmacological treatments are adopted in clinical practice and how their application can impact on patients’ outcomes. Patients will be followed for 1 year after admission.

Conclusion 

The ESC ACCA-EAPCI EORP ACS STEMI registry is an international registry of care and outcomes of patients hospitalized with STEMI. It will provide insights into the contemporary patient profile, management patterns, and 1-year outcome of patients with STEMI.

Abstract P1-13-05: Efficacy and safety of eflapegrastim confirmed in reducing severe neutropenia in breast cancer patients treated with myelosuppressive chemotherapy in the second Phase 3 randomized controlled multinational trial compared to pegfilgrastim (RECOVER trial)

Background:

Eflapegrastim is a novel investigational biologic comprised of recombinant human G-CSF covalently linked to the human immunoglobulin G4FC fragment using proprietary LAPSCOVERY™ technology with potentially unique distribution to areas rich in FcRn receptors. RECOVER is the second Phase 3 study to investigate the non-inferiority (NI) of eflapegrastim to pegfilgrastim in patients receiving chemotherapy for breast cancer. The first Phase 3 study, ADVANCE, has demonstrated the non-inferiority of eflapegrastim comparing to pegfilgrastim in the duration of severe neutropenia (DSN) in breast cancer patients receiving docetaxel and cyclophosphamide (TC) and was previously published at ASCO 2018 meeting.

TrialDesign:

Patients with Stage I to Stage IIIA breast cancer from centers in the USA, Canada, Poland, Hungary, South Korea and India were treated on Day 1 of each of four 21-day cycles with adjuvant or neo-adjuvant TC. On Day 2 of each cycle, patients received a single subcutaneous dose of either eflapegrastim 13.2 mg/0.6 mL (equivalent to 3.6 mg G-CSF) or pegfilgrastim (6 mg) in a 1:1 ratio. Patients had CBCs drawn on Day 1 prior to chemotherapy and Days 4-15 daily or until recovery of neutropenia in Cycle 1. CBC was also collected on Days 1, 4, 7, 10 and 15 in Cycles 2-4. The primary endpoint was to demonstrate the non-inferiority of eflapegrastim comparing to pegfilgrastim as measured by the mean DSN in Cycle 1 with NI margin of <0.62 day.

Results:

In a total of 237 intent-to-treat patients (randomized to 118 eflapegrastim; 119 pegfilgrastim), median age was 59 years (range 29 to 88 years); mean (SD) DSN was 0.31 (0.688) days for eflapegrastim and 0.39 (0.949) days for pegfilgrastim, demonstrating the non-inferiority (95% CI of ΔDSN: [-0.292, 0.129]; p<0.0001). Non-inferiority of eflapegrastim for DSN was maintained across all 4 cycles. There were no statistically significant differences in secondary endpoints: time to ANC recovery, depth of ANC nadir and incidence of FN at Cycle 1. The common Grade 3/4 adverse events observed in≥5%of patients were similar across both arms and were mainly hematologic including neutropenia, lymphopenia, anemia and leukopenia. Grade 3/4 bone pain and febrile neutropenia rates were similar across both arms and were less than 5%.

Conclusions:

Eflapegrastim, a novel long acting G-CSF demonstrated non-inferiority to pegfilgrastim in the reduction of DSN in breast cancer patients treated with TC and has validated the results from the first Phase 3 ADVANCE study. Eflapegrastim was safe and well-tolerated with a similar safety profile to pegfilgrastim.

Citation Format: Schwartzberg L, Bhat G, Mezei K, Lang I, Moon YW, Senviratne L, Chawla S, Cobb P, Yang Z. Efficacy and safety of eflapegrastim confirmed in reducing severe neutropenia in breast cancer patients treated with myelosuppressive chemotherapy in the second Phase 3 randomized controlled multinational trial compared to pegfilgrastim (RECOVER trial) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-13-05.

Plasminogen Activator Inhibitor-1 Levels in Patients with Chronic Angina Pectoris with or without Angiographic Evidence of Coronary Sclerosis

Increased plasma levels of plasminogen activator inhibitor-1 (PAI-1) have been shown to exist in 40 to 60% of patients with stable coronary artery disease and have been suggested to be responsible for the development of coronary thrombotic complications. However, it is also discussed whether PAI-1 elevation might mainly be due to variables like increased age or to reactive mechanisms caused e.g. by the chest pain itself. To exclude age dependent ui pain related influences, age-matched patients with stable angina pectoris (NHYA II) and angiographically proven coronary artery disease (CAD, n = 16) or without evidence for coronary sclerosis (variant angina, n = 10; angina-like syndrome with normal coronary angiogram, n = 5; non-CAD, n = 15) have been investigated for their plasma PAI-1 activity and t-PA antigen levels. The mean PAI activity in CAD patients (17.5 U/ml) was significantly higher than in non-CAD patients (9.6 U/ml) (p <0.0001). In the CAD patients no significant variation in plasma PAI-1 values could be demonstrated when related to the extent of the disease or to a history of previous myocardial infarction t-PA antigen was also elevated m CAD patients as compared to the non-CAD group (p <0.02). The results suggest therefore a strong correlation between coronary artery disease itself and elevated levels of components of the plasma fibrinolytic system.

Population Pharmacokinetics of Liposomal Irinotecan in Patients With Cancer

Nanoliposomal irinotecan (nal‐IRI) is a liposomal formulation of irinotecan with a longer half‐life (t_1/2), higher plasma total irinotecan (tIRI), and lower SN‐38 maximum concentration (C_max) compared with nonliposomal irinotecan. Population pharmacokinetic (PK) analysis of nal‐IRI was performed for tIRI and total SN‐38 (tSN38) using patient samples from six studies. PK‐safety association was evaluated for neutropenia and diarrhea in 353 patients. PK‐efficacy association was evaluated from a phase III study in pancreatic cancer NAPOLI1. Efficacy was associated with longer duration of unencapsulated SN‐38 (uSN38) above a threshold and higher C_avg of tIRI, tSN38, and uSN38. Neutropenia was associated with uSN38 C_max and diarrhea with tIRI C_max. Baseline predictive factors were race, body surface area, and bilirubin. Analysis identified PK factors associated with efficacy, safety, and predictive baseline factors. The results support the benefit of nal‐IRI dose of 70 mg/m² (free‐base; equivalent to 80 mg/m² salt base) Q2W over 100 mg/m² Q3W.

Evaluation of a semi-automated software program for the identification of vertebral fractures in children

AIM

To assess observer reliability and diagnostic accuracy in children, of a semi-automated six-point technique developed for vertebral fracture (VF) diagnosis in adults, which records percentage loss of vertebral body height.

MATERIALS AND METHODS

Using a semi-automated software program, five observers independently assessed T4 to L4 from the lateral spine radiographs of 137 children and adolescents for VF. A previous consensus read by three paediatric radiologists using a simplified algorithm-based qualitative technique (i.e., no software involved) served as the reference standard.

RESULTS

Of a total of 1,781 vertebrae, 1,187 (67%) were adequately visualised according to three or more observers. Interobserver agreement in vertebral readability for each vertebral level for five observers ranged from 0.05 to 0.47 (95% CI: -0.19, 0.76). Intra-observer agreement using the intraclass correlation coefficient (ICC) ranged from 0.25 to 0.61. The overall sensitivity and specificity were 18% (95% CI: 14-22) and 97% (95% CI: 97-98), respectively.

CONCLUSION

In contrast to adults, the six-point technique assessing anterior, middle, and posterior vertebral height ratios is neither satisfactorily reliable nor sensitive for VF diagnosis in children. Training of the software on paediatric images is required in order to develop a paediatric standard that incorporates not only specific vertebral body height ratios but also the age-related physiological changes in vertebral shape that occur throughout childhood.

Abstract P2-05-21: Predictive value of quantitative HER2 and HER3 levels combined with downstream signaling markers in HER2-positive advanced breast cancer patients treated with lapatinib

Background: Clinical correlates of lapatinib resistance have not been well defined. Previous studies implicated genes regulated by the estrogen receptor (ER) and activation or mutation of proteins downstream from HER family receptors. In the current study, HER2 and HER3 expression levels were quantitatively measured using a VeraTag® fluorescence-based assay, in addition to seven downstream signaling proteins determined by IHC. All biomarkers were correlated with overall survival (OS) in patients treated with lapatinib.

Methods: Formalin-fixed, paraffin-embedded samples were obtained from the primary tumor of 191 patients treated with lapatinib plus capecitabine following progression on trastuzumab. The HERmark® Breast Cancer Assay (Monogram Biosciences, South San Francisco) was used to quantify HER2 protein expression levels. HER3 protein expression was quantified using the VeraTag® technology (Monogram Biosciences). Expression of ER, PTEN, Cyclin E, HIF-2alpha, p-p70S6K, p-AMPK and p-MAPK were determined by IHC (Duchnowska et al., Oncotarget 2016; 7:550). OS analyses of HER2 and HER3 were stratified by key clinical variables, including stage and presence of a brain metastasis prior to lapatinib-based therapy.

Results: Among the downstream signaling molecules, HIF-2alpha (r = -0.23; p = 0.047) and ER (r = -0.27; p = 0.005) were negatively correlated with HER2 expression after adjustment for multiple testing. PTEN appeared to correlate with HER3, but was not significant after adjustment for multiple testing. OS was significantly shorter for both those below the cut-off level of positivity by the HERmark assay (HR = 1.8; p = 0.029), and those with above median HER2 levels (HR = 1.7; p = 0.009), as compared to cases with in between levels. The relationship between HER2 and OS is also captured by a U-shaped, parabolic function in HER2 (p = 0.005). Elevated HER3 showed a trend toward a correlation with longer OS (HR = 0.66/log; p = 0.16), somewhat stronger in the ER-negative subset (HR = 0.55/log; p = 0.085) and in the subset with above-median HER2 (0.48/log; p = 0.10), where inhibiting HER2 activation of HER3 may be more important. In multivariate Cox models, HER2 (parabola, intermediate HER2 best, p = 0.001), presence of brain metastases (HR = 2; p &lt; 0.001), ER (HR = 0.60; p = 0.009) and either p-p70S6K (HR = 0.66; p = 0.018) or p-AMPK (HR = 0.67; p = 0.022) were significantly associated with OS (p-p70S6K and p-AMPK were mutually correlated).

Conclusions: Patients with moderately increased HER2 levels may have best outcomes while receiving lapatinib following progression on trastuzumab. This supports recent findings of a less benefit from lapatinib in patients with high HER2 expression (Nunciforo et al., SABCS 2015, P3-07-08). HER3 levels do not seem to substantially impact the prognosis. Further studies are warranted to explore the predictive utility of quantitative HER2 and HER3 in guiding HER2-directed therapies.

Citation Format: Duchnowska R, Sperinde J, Czartoryska-Arlukowicz B, Mysliwiec P, Winslow J, Radecka B, Petropoulos C, Demlova R, Orlikowska M, Kowalczyk A, Lang I, Ziólkowska B, Debska-Szmich S, Merdalska M, Grela-Wojewoda A, Zawrocki A, Biernat W, Huang W, Jassem J. Predictive value of quantitative HER2 and HER3 levels combined with downstream signaling markers in HER2-positive advanced breast cancer patients treated with lapatinib [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-05-21.

Hofbauer cells of M2a, M2b and M2c polarization may regulate feto-placental angiogenesis

The human placenta comprises a special type of tissue macrophages, the Hofbauer cells (HBC), which exhibit M2 macrophage phenotype. Several subtypes of M2-polarized macrophages (M2a, M2b and M2c) exist in almost all tissues. Macrophage polarization depends on the way of macrophage activation and leads to the expression of specific cell surface markers and the acquisition of specific functions, including tissue remodeling and the promotion of angiogenesis. The placenta is a highly vascularized and rapidly growing organ, suggesting a role of HBC in feto-placental angiogenesis. We here aimed to characterize the specific polarization and phenotype of HBC and investigated the role of HBC in feto-placental angiogenesis. Therefore, HBC were isolated from third trimester placentas and their phenotype was determined by the presence of cell surface markers (FACS analysis) and secretion of cytokines (ELISA). HBC conditioned medium (CM) was analyzed for pro-angiogenic factors, and the effect of HBC CM on angiogenesis, proliferation and chemoattraction of isolated primary feto-placental endothelial cells (fpEC) was determined in vitro. Our results revealed that isolated HBC possess an M2 polarization, with M2a, M2b and M2c characteristics. HBC secreted the pro-angiogenic molecules VEGF and FGF2. Furthermore, HBC CM stimulated the in vitro angiogenesis of fpEC. However, compared with control medium, chemoattraction of fpEC toward HBC CM was reduced. Proliferation of fpEC was not affected by HBC CM. These findings demonstrate a paracrine regulation of feto-placental angiogenesis by HBC in vitro. Based on our collective results, we propose that the changes in HBC number or phenotype may affect feto-placental angiogenesis.

[Chronic thromboembolic pulmonary hypertension: Recommendations of the Cologne Consensus Conference 2016]

The 2015 European Guidelines on Pulmonary Hypertension did not cover only pulmonary arterial hypertension (PAH), but also other significant subgroups of pulmonary hypertension (PH). In June 2016, a Consensus Conference organized by the PH working groups of the German Society of Cardiology (DGK), the German Society of Respiratory Medicine (DGP) and the German Society of Pediatric Cardiology (DGPK) was held in Cologne, Germany to discuss open and controversial issues surrounding the practical implementation of the European Guidelines. Several working groups were initiated, one of which was dedicated to the diagnosis and treatment of chronic thromboembolic pulmonary hypertension (CTEPH). In every patient with PH of unknown cause CTEPH should be excluded. The primary treatment option is surgical pulmonary endarterectomy (PEA) in a specialized multidisciplinary CTEPH center. Inoperable patients or patients with persistent or recurrent CTEPH after PEA are candidates for targeted drug therapy. For balloon pulmonary angioplasty (BPA), there is currently only limited experience. This option - as PEA - is reserved to specialized centers with expertise for this treatment method. In addition, a brief overview is given on pulmonary artery sarcoma, since its surgical treatment is often analogous to PEA. The recommendations of this working group are summarized in the present paper.

Diagnostic accuracy of DXA compared to conventional spine radiographs for the detection of vertebral fractures in children

OBJECTIVES

In children, radiography is performed to diagnose vertebral fractures and dual energy x-ray absorptiometry (DXA) to assess bone density. In adults, DXA assesses both. We aimed to establish whether DXA can replace spine radiographs in assessment of paediatric vertebral fractures.

METHODS

Prospectively, lateral spine radiographs and lateral spine DXA of 250 children performed on the same day were independently scored by three radiologists using the simplified algorithm-based qualitative technique and blinded to results of the other modality. Consensus radiograph read and second read of 100 random images were performed. Diagnostic accuracy, inter/intraobserver and intermodality agreements, patient/carer experience and radiation dose were assessed.

RESULTS

Average sensitivity and specificity (95 % confidence interval) in diagnosing one or more vertebral fractures requiring treatment was 70 % (58-82 %) and 97 % (94-100 %) respectively for DXA and 74 % (55-93 %) and 96 % (95-98 %) for radiographs. Fleiss' kappa for interobserver and average kappa for intraobserver reliability were 0.371 and 0.631 respectively for DXA and 0.418 and 0.621 for radiographs. Average effective dose was 41.9 μSv for DXA and 232.7 μSv for radiographs. Image quality was similar.

CONCLUSION

Given comparable image quality and non-inferior diagnostic accuracy, lateral spine DXA should replace conventional radiographs for assessment of vertebral fractures in children.

KEY POINTS

• Vertebral fracture diagnostic accuracy of lateral spine DXA is non-inferior to radiographs. • The rate of unreadable vertebrae for DXA is lower than for radiographs. • Effective dose of DXA is significantly lower than radiographs. • Children prefer DXA to radiographs. • Given the above, DXA should replace radiographs for paediatric vertebral fracture assessment.