Echocardiographic systolic and diastolic function alterations in multiple myeloma patients treated with Carfilzomib

Funding Acknowledgements

Type of funding sources: None.

Background

Carfilzomib improves the prognosis of multiple myeloma (MM) patients, but significantly increases cardiovascular toxicity. The timing and effect of carfilzomib therapy on left ventricular function is still under investigation.

Purpose

We sought to assess the echocardiographic systo-diastolic changes, including global longitudinal strain (GLS), in patients treated with carfilzomib and to identify predictors of increased risk of cardiovascular adverse events (CVAEs) during therapy.

Methods

88 patients with MM performed a baseline cardiovascular evaluation comprehensive of transthoracic echocardiogram (TTE) before the start of Carfilzomib therapy and after about 6 months. All patients were clinically followed-up to early identify the occurrence of CVAEs for the whole therapy duration.

Results

After Carfilzomib treatment, mean GLS slightly decreased (-22.2% ± 2.6 vs -21.3% ± 2.5; p < 0.001). 58% of patients experienced CVAEs during therapy: 71% of them had uncontrolled hypertension, 29% had major CVAEs or CV events not related to arterial hypertension. GLS variation during therapy was not related to an increased risk of CVAEs; however, patients with baseline GLS ≥ -21% and/or left ventricular ejection fraction (LVEF) ≤ 60% had an increased risk of major CVAEs (OR = 6.2, p = 0.004;  OR = 3.7, p = 0.04, respectively). Carfilzomib led to an increased risk of diastolic dysfunction (5.6% vs 13.4% p = 0.04) and to a rise in E/e’ (8.9 ± 2.7 vs 9.7 ± 3.7; p = 0.006).

Conclusions

Carfilzomib leads to early LV function impairment early demonstrated by GLS changes and diastolic dysfunction. Baseline echocardiographic parameters, especially GLS and LVEF, might improve cardiovascular risk stratification before treatment.

Cardiovascular risk assessment in multiple myeloma patients undergoing carfilzomib therapy: a new risk prediction model for cardiovascular adverse events

Funding Acknowledgements

Type of funding sources: None.

Background

Cardiovascular adverse events (CVAEs) are closely related to Carfilzomib (CFZ) therapy in multiple myeloma (MM), but validated management protocols are lacking. Moreover, the incidence, nature and risk factors for each type of CVAEs are incompletely characterized.

Purpose

To assess if the European Myeloma Network Guidelines (EMN) protocol is effective on cardiovascular risk assessment before CFZ starting. A prediction model for estimating the probability of CVAEs was developed and validated. Major and hypertensive-related CVAEs were investigated.

Methods

A perspective study on 116 MM patients scheduled for CFZ therapy was conducted from 2015 to 2020. Before CFZ starting, a baseline evaluation, according to the EMN protocol, was performed; during the follow-up, the incidence of CVAEs was detected. The potential risk factors for CVAEs were identified and a risk score was developed.

Results

The rate of all-grade CVAEs was 44.8% (24.1% CTCAE≥3): 14.7% experienced major CVEAs (41.2% arrhythmias, 23.5% acute ischemic cardiopathy as most represented) and 30.2% hypertensive-related CVAEs. At baseline, five independent predictors for all-CVAEs were identified: office systolic blood pressure (p = 0.003), 24-hours blood pressure variability (p = 0.004), left ventricular mass (p = 0.015), pulse wave velocity (p = 0.002) and global longitudinal strain (p = 0.033). The resulting CVAEs risk score allows to define the low- and high-risk groups, obtaining a sensibility of 94% in predicting CVAEs (AUC 0.76).

Conclusions

The comprehensive evaluation of EMN Guidelines is effective in CVAEs prediction. The use of CVAEs risk score will identify the higher risk patients, targeting appropriate follow-ups and organizing effective risk mitigation strategies.

Instrumental determinants with CVAEs Parameters No CVAEs N = 64 [N (%)] CVAEs N = 52[N (%)] P value LV mass/BSA 85.30 ± 19.72 95.14 ± 21.75 0.013 LV hypertrophy [> = 95 g/m2 F > = 115 g/m2 M] 8 (12.7) 16 (30.8) 0.018 LV dilation 5 (9.3) 4 (8.9) 0.949 LV EF % 63.03 ± 6.56 61.96 ± 7.13 0.414 GLS % -22.37 ± 2.56 -21.3 ± 2.46 0.029 LV Diastolic dysfunction 1 (1.6) 0(0) 0.362 PWV 7.41 ± 1.63 8.55 ± 1.855 0.002 PWV ³ 8.75 m/s 10 (17.5) 24 (54.2) 0.000 SBP Systolic Blood Pressure; ABPM Ambulatory Blood Pressure Monitoring; BPV Blood Pressure Variability; BSA Body Surface Area; SD Standard Deviation; EF Ejection Fraction; GLS Global Longitudinal Strain; LV Left Ventricle; PWV Pulse Wave Velocity Abstract Figure. CVAEs risk score

P1375 Echocardiographic estimation of right ventricle wall tension: hemodynamic comparison and long term follow up

Introduction

Natural history of pulmonary hypertension (PH) is linked to right ventricle (RV) failure; in first phases of PH, coupling is preserved at the price of augmented RV wall tension (RVWT), which may represent an early sign of disease.

Methods

Patients with suspected PH, in absence of RV failure, underwent right heart catheterization and nearly-simultaneous echocardiography. We extrapolated RVWT from Laplace’s law as RV length × tricuspid regurgitation peak gradient (TRPG), and we correlated it with RV haemodynamic profile. Its impact on survival was tested.

Results

190 patients were enrolled; RVWT correlated with invasive measure of RV telediastolic pressure, mean pulmonary artery (PA) pressure, PA compliance, transpulmonary gradient, pulmonary vascular resistance, right atrial pressure and RV stroke work index (all p < 0.001). At a mean follow-up of five years and three months, RVWT predicted all-cause mortality at univariate and multivariate analysis (p 0.036, p 0,023); tricuspid annular plane systolic excursion (TAPSE) (p 0.536), RV fractional area change (p 0.383), RV S’ (p 0.076) and TAPSE/TRPG (p 0.181) did not.

Conclusions

We identified a novel echocardiographic predictor of precocious RV impairment, able to predict all-cause mortality at a long-term follow-up.

Regression: RVWT and invasive parameters Characteristics R - R2 p value mPAP 0.742 - 0.550 <0.001 PA pulsatory pressure 0.740 - 0.547 <0.001 RV differential pressure 0.794 - 0.630 <0.001 Mean RAP 0.326 - 0.106 <0.001 CI/RAP 0.209 - 0.044 0.012 RVSWI 0.326 - 0.106 <0.001 PA compliance 0.449 - .202 <0.001 PVR 0.531 - 0.282 <0.001 RV basal diameter 0.326 - 0.106 <0.001 RV medium diameter 0.403 - 0.162 <0.001 Right atrium area 0.204 - 0.042 0.013 RV FAC 0.382 - 0.146 <0.001 RV telediastolic area 0.347 - 0.120 <0.001 Correlation between RVWT and invasive haemodynamic parameters of RV function. mPAP, mean pulmonary artery pressure. RAP, right atrial pressure. CI, cardiac index. RVSWI, right ventricle stroke work index. PVR, pulmonary vascular resistance. RV, right ventricle. FAC, fractional area change.

Abstract P1375 Figure. RVWT and invasive hemodynamic profile

P4355Echocardiographic estimation of right ventricle wall tension: hemodynamic comparison and long term follow up

Introduction

Prognosis in pulmonary hypertension (PH) is strictly linked to right ventricle (RV) failure, which results from uncoupling between RV and the superimposed pressure load; in first phases, coupling between these two actors still be preserved, at the price of augmented right ventricle wall tension (RVWT).

Purpose

We sought to describe how to estimate RVWT with echocardiography, how it correlates with RV hemodynamics and if it may predict prognosis.

Methods

A total of 190 patients without overt RV failure, with suspected pulmonary hypertension (PH) to a previous echocardiography, underwent to right heart catheterization (RHC) and nearly-simultaneous echocardiography. We estimated RVWT according to Laplace law (RV length × tricuspid regurgitation peak gradient [TRPG]), in order to predict initial RV stress, and was correlated with RV hemodynamic profile; its potential prognostic impact was tested along with canonical RV function parameters.

Results

In patients enrolled in our study, RVWT correlated significantly with invasive estimation of right ventricle end diastolic pressure (R 0.343, p<0.001); a significant relationship between RVWT and several hemodynamic variables was observed (mean pulmonary artery pressure, pulmonary artery compliance, transpulmonary gradient, pulmonary vascular resistance, RV telediastolic pressure, right atrial pressure, RV stroke work index; all p<0.001). At a mean follow up of five years and three months, only RVWT predicted all-cause mortality (p 0.036), while TAPSE, TAPSE/TRPG, RV fractional area change and RV S' wave did not.

Correlation: RWVT and RV hemodynamic Hemodynamic variable R R2 p value Mean pulmonary artery pressure 0.742 0.550 <0.001 RV differential pressure 0.794 0.630 <0.001 Pulmonary artery pulsatory pressure 0.740 0.547 <0.001 Mean right atrium pressure 0.326 0.106 <0.001 Cardiac index/right atrial pressure 0.209 0.044 0.012 RV stroke work index 0.588 0.346 <0.001 Pulmonary artery compliance 0.449 0.202 <0.001 Pulmonary vascular resistance 0.531 0.282 <0.001

Prognosis: different RV variables

Discussion

We identified a novel bedside echocardiographic predictor of altered RV hemodynamic, which results precociously altered in patients without overt RV failure, and able to predict all cause mortality at a long term follow up. Further studies are needed to confirm its role in PH patients.

Prevention, monitoring and treatment of cardiovascular adverse events in myeloma patients receiving carfilzomib A consensus paper by the European Myeloma Network and the Italian Society of Arterial Hypertension

BACKGROUND

The novel proteasome inhibitor carfilzomib alone or in combination with other agents is already one of the standard therapies for relapsed and/or refractory multiple myeloma (MM) patients and produces impressive response rates in newly diagnosed MM as well. However, carfilzomib-related cardiovascular adverse events (CVAEs) - including hypertension (all grades: 12.2%; grade ≥3: 4.3%), heart failure (all grades: 4.1%; grade ≥3: 2.5%) and ischemic heart disease (all grades: 1.8%; grade ≥3: 0.8%) - may lead to treatment suspensions. At present, there are neither prospective studies nor expert consensus on the prevention, monitoring and treatment of CVAEs in myeloma patients treated with carfilzomib.

METHODS

An expert panel of the European Myeloma Network in collaboration with the Italian Society of Arterial Hypertension and with the endorsement of the European Hematology Association aimed to provide recommendations to support health professionals in selecting the best management strategies for patients, considering the impact on outcome and the risk-benefit ratio of diagnostic and therapeutic tools, thereby achieving myeloma response with novel combination approaches whilst preventing CVAEs.

RESULTS

Patients scheduled to receive carfilzomib need a careful cardiovascular evaluation before treatment and an accurate follow-up during treatment.

CONCLUSIONS

A detailed clinical assessment before starting carfilzomib treatment is essential to identify patients at risk for CVAEs, and accurate monitoring of blood pressure and of early signs and symptoms suggestive of cardiac dysfunction remains pivotal to safely administer carfilzomib without treatment interruptions or dose reductions.

Sub-MIC effects of a proline-rich antibacterial peptide on clinical isolates of Acinetobacter baumannii

INTRODUCTION

Acinetobacter baumannii is one of the most important nosocomial pathogens, mainly due to its ability to accumulate antibiotic-resistances and to persist in the hospital environment - characteristics related to biofilm production. It is well-known that A. baumannii is inhibited by the proline-rich peptide Bac7(1-35), but its putative effects at sub-MICs were never considered.

AIMS

We examined the sub-MIC effect of Bac7(1-35) on the growth rate, resistance induction and some A. baumannii features linked to virulence.

METHODOLOGY

Growth kinetics in the presence of sub-MICs of Bac7(1-35) were evaluated spectrophotometrically. Peptide uptake was quantified by cytometric analysis. The ability of Bac7(1-35) to interfere with biofilm production was investigated by the crystal violet method and confocal microscopy. Bacterial motility was observed at the interphase between a layer of a semi-solid medium and the polystyrene bottom of a Petri dish. The induction of resistance was evaluated after serial passages with sub-MICs of the peptide.

RESULTS

Although the MIC of Bac7(1-35) was between 2-4 µM for all tested strains, its effect on the growth rate at sub-MICs was strain-dependent and correlated with the amount of peptide internalized by each strain. Sub-MICs of Bac7(1-35) induced a strongly strain-dependent effect on biofilm formation and reduced motility in almost all strains, but interestingly the peptide did not induce resistance.

CONCLUSION

Bac7(1-35) is internalized into A. baumannii and is able to inhibit biofilm formation and bacterial motility, without inducing resistance. This study stresses the importance of considering possible effects that antimicrobials could have at sub-MICs, mimicking a common condition during antibiotic treatment.

Evaluation of Cardiovascular Toxicity Associated with Treatments Containing Proteasome Inhibitors in Multiple Myeloma Therapy

INTRODUCTION

Recently new treatment options have substantially increased survival for patients with relapsed and/or refractory multiple myeloma (RRMM). Among these, proteasome inhibitors (PI), such as bortezomib and carfilzomib, offer high response rate and prolonged survival. These agents are generally well tolerated but demonstrated a significant cardiovascular toxicity, mostly for regimen containing carfilzomib.

AIM

To assess the cardiovascular damage in patients treated with PI for RRMM.

METHODS

28 consecutive subjects treated with PI for RRMM were evaluated and compared with a population of 22 control (Con) subjects, matched for age, sex and mean 24 h blood pressure (24hMBP). All individuals underwent trans-thoracic echocardiography, ambulatory blood pressure monitoring and pulse wave velocity (PVW) study.

RESULTS

PI patients did not have significant differences in blood pressure load and PWV compared to controls. Among echocardiographic parameters, the global longitudinal strain (GLS) was significantly decreased in PI subjects (p = 0.02). The GLS was significantly lower also considering only patients treated with carfilzomib. Moreover, among carfilzomib patients, we found increase values of left ventricle mass indexed by BSA (LVMi; p = 0.047). After correction for age, sex, BSA, 24hMBP and morphological and functional parameters of LV, treatment with PI and carfilzomib were significantly associated with GLS (p = 0.01; p = 0.036, respectively).

CONCLUSIONS

PI treatment is associated with subclinical LV dysfunction in patients with RRMM compared to controls, as demonstrated by lower GLS values. These results are confirmed also considering patients treated with carfilzomib. Moreover, in this subgroup of patients, the LVMi is also increased, suggesting higher cardiotoxicity with this treatment.

Biofilms Developed on Dental Implant Titanium Surfaces with Different Roughness: Comparison Between In Vitro and In Vivo Studies

Microbial biofilms developed on dental implants play a major role in perimplantitis' pathogenesis. Many studies have indicated that surface roughness is the main feature favoring biofilm development in vitro, but its actual influence in vivo has still to be confirmed. In this study, the amount of biofilm formed on differently treated titanium surfaces, showing distinct roughness, has been examined both in vivo and in vitro by Confocal Laser Scanning Microscopy. In vitro studies availed of biofilm developed by Pseudomonas aeruginosa or by salivary bacteria from volunteer donors. In vivo biofilm production was obtained by exposing titanium discs to the oral cavity of healthy volunteers. In vitro experiments showed that P. aeruginosa and, to a lesser extent, salivary bacteria produce more biomass and develop thicker biofilms on laser-treated and sandblasted titanium surfaces with respect to machined ones. In vivo experiments confirmed that bacterial colonization starts on sites of surface unevenness, but failed to disclose biomass differences among biofilms formed on surfaces with different roughness. Our study revealed that biofilm developed in vitro is more easily influenced by surface features than biofilm formed by complex communities in the mouth, where the cooperation of a variety of bacterial species and the presence of a wide range of nutrients and conditions allow bacteria to optimize substrate colonization. Therefore, quantitative differences observed in vitro among surfaces with different characteristics may not be predictive of different colonization rates in vivo.

Spread of Vancomycin-Resistant Enterococcus faecium Isolates Despite Validated Infection Control Measures in an Italian Hospital: Antibiotic Resistance and Genotypic Characterization of the Endemic Strain

An alarming increase of vancomycin-resistant Enterococcus faecium (VREfm) isolates was detected in an Italian referral hospital subjected to policies of infection control validated by the Joint Commission International. Analysis of the population structure of 122 consecutive, nonreplicate VREfm isolates collected over an 18-month period identified a single major clone that spread around the whole hospital, rapidly establishing an endemic state. It belonged to sequence type (ST) 17 and showed a highly multidrug-resistant phenotype, being resistant to all antimicrobial classes for the carriage of several resistance determinants. Furthermore, some strains with decreased susceptibility to daptomycin were detected. Eighteen out of the 122 isolates did not group in the major clone. They showed a low spreading potential inside the hospital wards, even if most of them displayed a multidrug-resistant phenotype and belonged to a hospital-adapted lineage. Causes that led to the VREfm endemic state have not been fully elucidated. However, it is conceivable that the increase in systemic antibiotic consumption and the use of selective digestive tract decontamination, including vancomycin in critically ill patients during the period before 2014, may have played a role in the ST17 clone dissemination, but additional traits conferring high fitness in hospital environment cannot be excluded.

In silico analysis of the anti-hypertensive drugs impact on myocardial oxygen balance

Hypertension is a very common pathology, and its clinical treatment largely relies on different drugs. Some of these drugs exhibit specific protective functions in addition to those resulting from blood pressure reduction. In this work, we study the impact of commonly used anti-hypertensive drugs (RAAS, [Formula: see text] and calcium channel blockers) on myocardial oxygen supply-consumption balance, which plays a crucial role in type 2 myocardial infarction. To this aim, 42 wash-out hypertensive patients were selected, a number of measured data were used to set a validated multi-scale cardiovascular model to subject-specific conditions, and the administration of different drugs was suitably simulated. Our results ascribe the well-known major cardioprotective efficiency of [Formula: see text] blockers compared to other drugs to a positive change of myocardial oxygen balance due to the concomitant: (1) reduction in aortic systolic, diastolic and pulse pressures, (2) decrease in left ventricular work, diastolic cavity pressure and oxygen consumption, (3) increase in coronary flow and (4) ejection efficiency improvement. RAAS blockers share several positive outcomes with [Formula: see text] blockers, although to a reduced extent. In contrast, calcium channel blockers seem to induce some potentially negative effects on the myocardial oxygen balance.

Biofilms from Klebsiella pneumoniae: Matrix Polysaccharide Structure and Interactions with Antimicrobial Peptides

Biofilm matrices of two Klebsiella pneumoniae clinical isolates, KpTs101 and KpTs113, were investigated for their polysaccharide composition and protective effects against antimicrobial peptides. Both strains were good biofilm producers, with KpTs113 forming flocs with very low adhesive properties to supports. Matrix exopolysaccharides were isolated and their monosaccharide composition and glycosidic linkage types were defined. KpTs101 polysaccharide is neutral and composed only of galactose, in both pyranose and furanose ring configurations. Conversely, KpTs113 polysaccharide is anionic due to glucuronic acid units, and also contains glucose and mannose residues. The susceptibility of the two strains to two bovine cathelicidin antimicrobial peptides, BMAP-27 and Bac7(1–35), was assessed using both planktonic cultures and biofilms. Biofilm matrices exerted a relevant protection against both antimicrobials, which act with quite different mechanisms. Similar protection was also detected when antimicrobial peptides were tested against planktonic bacteria in the presence of the polysaccharides extracted from KpTs101 and KpTs113 biofilms, suggesting sequestering adduct formation with antimicrobials. Circular dichroism experiments on BMAP-27 in the presence of increasing amounts of either polysaccharide confirmed their ability to interact with the peptide and induce an α-helical conformation.

Epidemic Dissemination of a Carbapenem-Resistant Acinetobacter baumannii Clone Carrying armA Two Years After Its First Isolation in an Italian Hospital

This study describes the dissemination of a carbapenem-resistant Acinetobacter baumannii (CRAB) strain in a university hospital in Northeast Italy. Characterization of the outbreak strain was combined with a retrospective analysis of all CRAB isolates collected in the same hospital during the 5 years preceding the outbreak, with the aim of elucidating the origin of the epidemic spread. The outbreak strain was shown to belong to the International Clone II and carry the bla_OXA-23 gene, flanked by two ISAba1 sequences in opposite orientation (Tn2006 arrangement). The epidemic clone harbored also the bla_OXA-66 allele of the carbapenemase intrinsic to A. baumannii, the determinant of ArmA 16S rRNA methylase and a class 1 integron, with the aacA4, catB8, and aadA1 cassette array. Genotype analysis, performed by macrorestriction analysis and VRBA, revealed that isolates related to outbreak strain had been sporadically collected from inpatients in the 2 years preceding outbreak start. Carriage of bla_OXA-66, armA, and the integron further supported relatedness of these isolates to the outbreak clone. Outbreak initially involved three medical wards, typically hosting elderly patients with a history of prolonged hospitalization. The study highlights the need to adopt strict infection control measures also when CRAB isolation appears to be a sporadic event.

PEGylation of the peptide Bac7(1-35) reduces renal clearance while retaining antibacterial activity and bacterial cell penetration capacity

The proline-rich antibacterial peptide Bac7(1-35) protects mice against Salmonella typhimurium infection, despite its rapid clearance. To overcome this problem the peptide was linked to a polyethylene glycol (PEG) molecule either via a cleavable ester bond or via a non-hydrolysable amide bond. Both the PEGylated conjugates retained most of the in vitro activity against S. typhimurium. In addition, the ester bond was cleaved in human serum or plasma, releasing a carboxymethyl derivative of Bac7(1-35) which accounts for a higher activity of this peptide with relative to the other, non-hydrolysable form. Both PEGylated peptides maintained the capacity of the unconjugated form to kill bacteria without permeabilizing the bacterial membranes, by penetrating into cells. They exploited the same transporter as unmodified Bac7(1-35), suggesting it has the capacity to internalize quite sizeable cargo if this is linked to Bac7 fragment. PEGylation allows the peptide to have a wide distribution in mice, and a slow renal clearance, indicating that this strategy would improve the bioavailability of Bac7, and in principle of other antimicrobial peptides. This can be an equally important issue to reducing cytotoxicity for therapeutic use of these antibacterials.

Identification of bacterial infections and clinical manifestation associated with cytomegalovirus in liver transplantation patients

INTRODUCTION

Liver transplantation has become the most effective therapy for the treatment of patients with end-stage liver disease. With new immunosuppressive agents the incidence of acute rejection has been significantly reduced, but infection has become a serious problem.

OBJECTIVE

Our objective was to correlate cytomegalovirus (CMV) positivity of antigenemia and polymerase chain reaction (PCR) with clinical manifestations and bacterial infections among patients undergoing liver transplantation.

METHODS

This prospective study included patients monitored for 6 months for early detection of CMV infection. Sample collections were performed at the time of surgery and weekly until the second month followed by fortnightly in the third month, and monthly in the fourth to sixth month. CMV infection was defined by positive antigenemia (>3 cells) or 2 positive PCR tests associated or not with clinical symptoms. The methodology for the diagnosis of bacterial infection was through biochemical tests and the automated VITEK/bioMérieux (identification and antibiogram) using samples of urine and blood cultures. Chi-square test was used for dicotomic variables with significant differences when P < .05.

RESULTS

Sixteen patients (32%) had CMV infections, including 13 (81%) with concomitant infections. Thirty-four patients (68%) did not have CMV infections and 8 of these (24%) had bacterial infection. There was a high correlation with bacterial infections among CMV-positive patients.

CONCLUSION

Bacterial infections after liver transplantation were associated with CMV infection.

Near-infrared spectroscopy measure of limb peripheral perfusion in neonatal arterial thromboembolic disease

AIM

In critically ill neonates, peripheral perfusion and oxygenation assessment may provide indirect information on circulatory failure in limb arterial thromboembolic emergencies. Aims of our study were: 1) to evaluate the changes on tissue oxygenation index, oxyhemoglobin, deoxyhemoglobin and blood volume obtained by near-infrared spectroscopy (NIRS) on the infants legs; 2) to compare them with ultrasonographic data.

METHODS

Tissue oxygenation index (TOI), oxyhemoglobin (O2Hb), deoxyhemoglobin (HHb) and blood volume (BV) differences were assessed by NIRS on the calf of 8 newborn infants (median weight 1995, range 585-3010 g; median gestational age 32.5, range 26-40 wks). An ultrasonographic scan of the arterial system was performed before the NIRS measurements, to validate the site of arterial occlusion.

RESULTS

A t-test for independent samples showed lower values in the affected limb for all NIRS measurements. TOI measurements displayed lower values in the thromboembolic limb (mean 44.79±12%) versus unaffected (mean 47.95±17.08%) (P=0.0001). Mean (SD) peak systolic velocity in the patent artery below the occlusion decreased from 108±25 cm/s in the normal limb to 25.6±28 cm/s in the thrombus site (P=0.02).

CONCLUSION

In neonatal intensive care units, measurement of limb peripheral perfusion and oxygenation seems to be clinically useful in arterial thromboembolic emergencies.

WITHDRAWN: Left atrial function and arterial hypertension

Left atrial enlargement is frequently observed in many cardiac diseases. One of the main determinants of left atrial size is ventricular diastolic function. It has recently been suggested that left atrial volume might be the morphophysiologic expression of long-term modifications induced by diastolic function. Furthermore, left ventricular remodelling, such as it happens in hypertensive patients, is another important determinant of atrial volume. All the volumetric modifications of the left atrium, during cardiac cycle, are involved in hypertensive damage. Therefore, left atrial function impairment represents the result of morphological and haemodynamic alterations observed in hypertension. Actually, many techniques, invasive and non-invasive, are available with the purpose to investigate the real atrial dimensions and provide a suitable assessment of atrial function. Recently, it has been demonstrated that the degree of left atrial enlargement is associated with adverse prognosis in different clinical setting. The predictive value of left atrial volume seems to be independent of left ventricular systolic and diastolic function, but the use of left atrial volume for risk stratification is yet an evolving science: more data are required with respect to the natural history of left atrial remodelling in disease, the degree of left atrial modifiability with therapy and whether regression of left atrial size translates into improved cardiovascular outcome.Journal of Human Hypertension advance online publication, 14 August 2008; doi:10.1038/jhh.2008.96.

Baroreflex sensitivity is impaired in essential hypertensives with central obesity

Recently, much interest has focussed on the potential interaction between sympathetic nervous system and global cardiovascular risk. We investigated how baroreflex sensitivity (BRS), an index of autonomic function, interacts with central obesity (CO) in an essential hypertensive (EH) population. We selected 170 EHs and 43 normotensives (NT), (median age 47.3+/-11.3 and 49.1+/-13 years, respectively). Anthropometric parameters were measured for each and BRS was evaluated by a non-invasive method using Portapres TNO. The BRS evaluation was made using the sequences method. Systolic blood pressure (SBP) and heart rate were significantly higher in EH (P<0.001 and P=0.007, respectively). BRS was significantly greater in NT (P=0.02), and was associated inversely with waist circumference (WC) (P=0.005), but not with SBP or with other metabolic risk factors. Body mass index, total and high-density lipoprotein cholesterol, age and WC were not significantly different between the two groups. These results were confirmed by age pounded analysis. Finally, a separate analysis of the hypertensive group with CO (n=84) demonstrated a significantly lower BRS compared with the other hypertensive patients (n=86) (P<0.001). BRS is associated with WC but not with arterial pressure values and metabolic risk factors. Hypertensive subjects with CO show an impairment of BRS. Owing to its association with abdominal fat distribution and subsequently insulin resistance, BRS could represent a further and reliable index for evaluation of global cardiovascular risk in hypertensive patients.

Energy cost of swimming of elite long-distance swimmers

The aim of this study was: (1) to assess the energy cost of swimming (C(s), kJ km(-1)) in a group of male (n = 5) and female (n = 5) elite swimmers specialised in long-distance competitions; (2) to evaluate the possible effect of a 2-km trial on the absolute value of C(s). C(s) was assessed during three consecutive 400-m trials covered in a 50-m pool at increasing speeds (v1, v2, v3). After these experiments the subjects swam a 2-km trial at the 10-km race speed (v2km) after which the three 400-m trials were repeated at the same speed as before (v5 = v1, v6 = v2, v7 = v3). C(s) was calculated by dividing the net oxygen uptake at steady state VO2ss by the corresponding average speed (v, m s(-1)). VO2ss was estimated by using back extrapolation technique from breath-to-breath VO2 recorded during the first 30 s of recovery after each test. C(s) increased (from 0.69 kJ m(-1) to 1.27 kJ m(-1)) as a function of v (from 1.29 m s(-1) to 1.50 m s(-1)), its values being comparable to those measured in elite short distance swimmers at similar speeds. In both groups of subjects the speed maintained during the 2-km trial (v2km) was on the average only 1.2% faster than of v2 and v6 (P>0.05), whereas C(s) assessed at the end of the 2-km trial (v2km) turned out to be 21 +/- 26% larger than that assessed at v2 and v6 (P<0.05); the average stroke frequency (SF, cycles min(-1)) during the 2-km trial turned to be about 6% (P<0.05) faster than that assessed at v2 and v6. At v5, C(s) turned out to be 19 +/- 9% (P<0.05) and 22 +/- 27% (0.1 < P = 0.05) larger than at v1 in male and female subjects (respectively). SF was significantly faster (P<0.05, in male subjects) and the distance per stroke (Ds = v/SF) significantly shorter (P<0.05) in female subjects at v5 and v6 than at v1 and v2. These data suggest that the increase of C(s) found after the 2-km trial was likely related to a decrease in propelling efficiency, since the latter is related to the distance per stroke.