Long-term follow-up of percutaneous balloon mitral valvuloplasty for mitral stenosis: an old but needed player

Funding Acknowledgements

Type of funding sources: None.

Background

In the era of innovative transcatheter valve interventions, percutaneous balloon mitral valvuloplasty (PBMV) remains the primary treatment option in anatomic suitable patients. 

Purpose

This study aimed to evaluate longterm follow-up (FU) of PBMV and to determine predictors of MACE. 

Methods

Between 1991 and June 2021, 202 consecutive patients underwent PBMV in a single tertiary centre. Clinical data, echocardiographic parameters, and MACE (cardiovascular mortality, need for percutaneous or surgical mitral reintervention and hospitalization for heart failure) were analysed. Predictors of MACE were determined by Cox regression analysis. 

Results

Mean age was 47.3 ± 13.6 years, 89.6% female, 47.3% patients presenting atrial fibrillation. Mean Wilkins score was 7.6 ± 1.4, 51.5% had mild or moderate mitral regurgitation and mean pulmonary artery systolic pressure (PASP) of 46.7 ± 17.1 mmHg. Mean pre MVA and mean mitral valve (MV) gradient were 1.1 ± 0.2 cm2 and 10.8 ± 5.6 mmHg, respectively.  Successful PMBV was achieved in 89.1%. 

During a mean FU of 12.0 ± 8.8 years, there were 25 deaths (12.4%) and 33.3% needed MV reintervention (6.5% underwent PBMV and 29.7% needed MV surgery). At univariate analysis, previous MV intervention [HR = 1.95 (1.02–3.72), p < 0.05],  Wilkins score [HR = 1.22 (1.01–1.47), p < 0.05],  pre mean MV gradient≥8 [HR = 0.62 (0.38–1.00), p < 0.05],  mean MV gradient after procedure [HR = 1.37 (1.19–1.58), p < 0.05] and PASP >45 mmHg [HR = 3.29 (1.13–9.55), p < 0.05] were predictors of MV reintervention. At multivariate analysis, pre mean MV gradient≥8 [HR = 0.17 (0.037–0.81), p < 0.05] and mean MV gradient after procedure were independent predictors of MV reintervention [HR = 1.74 (1.21–2.49), p < 0.05]. Wilkins score [HR = 1.29 (1.06–1.57), p < 0.05] and mean MV gradient after procedure [HR = 1.41 (1-21–1.63), p < 0.05] were independent predictors of MACE. Cumulative event-free survival at 10 and 20 years were 72.0 and 46.0%, respectively. 

Conclusions

PBMV remains a reliable and efficient therapeutic option of mitral stenosis, warranting event-free survival at 10 years in most patients selected for the procedure. Mean MV gradient after procedure was independent predictor of MV reintervention and MACE during follow-up. Abstract Figure.  Abstract Figure.

Extracorporeal Membrane Oxygenation Dependent COVID19 Hospital Transfers

Introduction

The World Health Organization has recorded over 8 Million cases of COVID19 as of October 2020. Despite receiving appropriate lung protective ventilation and medical treatment, some of these patients develop refractory hypoxemia and acute respiratory distress syndrome . Extracorporeal membrane oxygenation has been recognized as a lifesaving therapy for patients with ARDS secondary to COVID19. There are few centers in the United States equipped with the necessary staff and the experience to take care of such critically ill patients. Some patients are too ill to be transferred with conventional mechanical ventilation, and they require interhospital transport while on ECMO.

Case Report

We have developed a highly specialized ECMO Deployment Team dedicated to the cannulation and transport of COVID19 patients while on venous-venous (VV) ECMO or venous-arterial (VA) ECMO. We use routine bedside ECMO cannulation via bilateral femoral vessels configuration at the outside hospital. The patient is stabilized and transported by air or ground to one of our affiliated hospitals.Here we present a series of five patients who were cannulated by our team at an outside institution and transported while on ECMO support to one of our three system hospitals. Patient ages ranged between 49-64 years old. Four patients required VV ECMO for severe hypoxemia secondary to COVID19 ARDS. One patient required VA ECMO due to viral myocarditis secondary to COVID19. Time on ECMO ranged from 9-33 days. Three of the five patients recovered successfully and were discharged home, rehab or LTAC. One patient is still currently on ECMO and one patient is deceased. There were no reported or documented transmission of COVID19 to the members of the ECMO deployment team.

Summary

The potential for survival of the critically ill due to COVID19 often demands a higher level of care. However, stable transport to an appropriate institution presents a limiting factor. Our method of a dedicated ECMO Deployment Team appears to provide favorable outcome for these patients.

Myocardial work brings a new insight into left ventricule remodelling in cardiooncology patients

Funding Acknowledgements

Type of funding sources: None.

Introduction

Serial echocardiographic assessment of 2D left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS) is the gold standard screening method for cancer therapeutics-related cardiac dysfunction (CTRCD). Non-invasive left ventricular (LV) pressure-strain loop (PSL) provides a novel method of quantifying myocardial work (MW) with potential advantages, as it incorporates measurements of myocardial deformation and LV pressure.

Purpose

To evaluate the impact of cardiotoxic treatments in MW indices.

Methods

Prospective study of female breast cancer patients (P) submitted to therapy (TH) who underwent serial monitoring by 2D, 3D transthoracic echocardiography (TTE) and concomitant blood pressure assessment. P were evaluated at T0, T1 and T2 (before, ≥6 and ≥12 months after starting TH). PSL analysis allowed the calculation of the following indices: Global Work Index (GWI), Global Constructive Work (GCW), Global Work Waste (GWW) and Global Work Efficiency (GWE). CTRCD was defined as an absolute decrease in 2D LVEF > 10% to a value < 54% or a relative decrease in 2D GLS > 15%, according to literature. 

Results

122 patients (mean age 54.7 ± 12.0 years), mostly treated with anthracyclines (77.0%, cumulative dose 268.6 ± 71.8mg/m2), anti-HER (75.4%) and radiotherapy (77.0%) were included. 2D and 3D LVEF were significantly reduced during TH, however remaining within the limits of normality (2D LVEF T0-T1 64.2 ±7.6 vs 61.1 ± 8.2%, p = 0.006 and 3D LVEF T0-T1 60.2 ± 6.7 vs 56.9 ±6.3%, p = 0.022). 2D GLS was also more impaired at T1 (-19.8 ± 2.7% vs -18.5 ± 3.0%, p = 0.003).

All MW indices were significantly reduced at T1 compared to baseline (GWI 1756.9 ± 319.2 vs 1614.3 ± 338.5mmHg%, p = 0.005; GCW 2105.6 ± 352.0 vs 1970.5 ± 376.2 mmHg%, p = 0.015; GWW 121.1 ± 66.6 vs 161.1 ± 84.1 mmHg%, p = 0.001; GWE 93.5 ± 3.1 vs 91.1 ± 4.5%, p = 0.001). Between T1 and T2 no statistical difference was found but a partial recovery of parameters was observed when comparing T2 to T0 (GWI (T2) 1650.6 ± 357.5 mmHg%, p = 0.035; GCW (T2) 2013.3 ± 379.3 mmHg%, p = 0.086; GWW (T2) 148.0 ± 85.0 mmHg%, p = 0.02 and GWE (T2) 92.0 ± 4.7%, p = 0.012). 

During a mean follow-up of 14.9 ± 9.3 months, 36 patients (29.5%) developed CTRCD.  P presenting CTRCD revealed a significant decrease in GWI and GWE at T1 comparing with women without CTRCD (GWI 1.8 ± 21.6 vs -14.2 ± 18.5%, p = 0.004 and GWE -1.0 ±3.0 vs -3.6 ±3.9%, p = 0.005). GWW had a substantially increase at T1 in P with cardiotoxicity (27.6 ± 76.3% vs 64.1 ± 68.0%, p = 0.051).

Conclusion

Left ventricular systolic function study with MW showed a reduction in cardiac performance with a peak at 6 months from the start of chemotherapy and partial recovery after term. Assessment of myocardial deformation parameters, namely MW, proved to be a useful tool for a better characterisation of cardiac remodelling, and could enhance patient selection for cardioprotective therapeutics.

Abstract Figure. TTE parameters

The Insecticidal Activity of Rhinella schneideri (Werner, 1894) Paratoid Secretion in Nauphoeta cinerea Cocroaches

Rhinella schneideri is a common toad found in South America, whose paratoid toxic secretion has never been explored as an insecticide. In order to evaluate its insecticidal potential, Nauphoeta cinerea cockroaches were used as an experimental model in biochemical, physiological and behavioral procedures. Lethality assays with Rhinella schneideri paratoid secretion (RSPS) determined the LD₅₀ value after 24 h (58.07µg/g) and 48 h exposure (44.07 µg/g) (R² = 0.882 and 0.954, respectively). Acetylcholinesterase activity (AChE) after RSPS at its highest dose promoted an enzyme inhibition of 40%, a similar effect observed with neostigmine administration (p < 0.001, n= 5). Insect locomotion recordings revealed that RSPS decreased the distance traveled by up to 37% with a concomitant 85% increase in immobile episodes (p < 0.001, n = 36). RSPS added to in vivo cockroach semi-isolated heart preparation promoted an irreversible and dose dependent decrease in heart rate, showing a complete failure after 30 min recording (p < 0.001, n ≥ 6). In addition, RSPS into nerve-muscle preparations induced a dose-dependent neuromuscular blockade, reaching a total blockage at 70 min at the highest dose applied (p < 0.001, n ≥ 6). The effect of RSPS on spontaneous sensorial action potentials was characterized by an increase in the number of spikes 61% (p < 0.01). Meanwhile, there was 42% decrease in the mean area of those potentials (p < 0.05, n ≥ 6). The results obtained here highlight the potential insecticidal relevance of RSPS and its potential biotechnological application.

P747 Echocardiographic evaluation of haemoglobinopathies patients and their correlation with haematologic determinants

Background

Although heart disease in haemoglobinopathy have dramatically reduced with modern therapy, cardiac complications are still a leading cause of morbimortality. It became essential to detect cardiac complications in early stages in order to provide specific therapy and to improve prognosis. Transthoracic echocardiography (TTE) has a paramount role in this field.

Purpose

To evaluate cardiac function in haemoglobinopathy patients and to correlate echocardiographic parameters with haematological determinants.

Methods

Retrospective analysis of haemoglobinopathy patients (pts) referred to a tertiary centre for cardiac evaluation and transthoracic echocardiography. Epidemiological, clinical, laboratory and echocardiographic data were analysed. Comparations between echocardiographic data and haemoglobin and serum ferritin levels were performed (independent T test). P value &lt;0.05 was considered statistically significant.

Results

55 pts were included: 58% female, mean age 37.9 ± 10.9 years, 85% with sickle cell disease, 13% (N = 7) with previous thromboembolic event and 20% (N = 11) with documented hemosiderosis. 36% (N = 20) were symptomatic (9 pts with palpitations, 6 pts with thoracic pain and 5 pts with exertion dyspnea – New York Heart Association class II). The mean haemoglobin level was 8.96 ± 1.91 g/dL and serum ferritin 1335.5 ± 2452 ng/mL. All patients had preserved left and right ventricular systolic function (TAPSE 27.1 ± 4.9mm) The mean left ventricular (LV) end-diastolic diameter indexed to body surface area (female 32.2 ± 4.7mm/m2; male: 31.2 ± 4.0mm/m2) and LV mass index (female 105.6 ± 31.4g/m2; male: 134.7 ± 97.3g/m2) were increased in both genders, although interventricular septum thickness was in the superior normal range (mean 9.3 ± 1.6mm). Left atrium enlargement was also present (29.9 ± 8.4mm/m2). The mean global ratio between early mitral inflow velocity and mean (septal and lateral) mitral annular early diastolic velocity (E/e") was 7.5 ±2.3, and 12 pts (21.8%) had impairment of LV diastolic function. Global longitudinal strain (GLS) was assessed in 35 pts, with a mean value of 19.6 ± 2.9%. 40% (14 pts) had GLS &gt; -18%, being the septal wall the most frequently affected. Pulmonary hypertension was rare (3 pts), with mean arterial pulmonary pressure of 27.7 ± 7.0mmHg. An agreement was found between serum ferritin levels and GLS impairment defined as GLS &gt; -18% (2649ng/ml vs 549ng/ml, p = 0.04). Pts with diastolic dysfunction had a trend to higher serum ferritin levels (2753ng/ml vs 1001ng/ml, p = 0.06). The haemoglobin levels did not correlate with echocardiographic parameters.

Conclusion

In the study population of haemoglobinopathy pts, mainly constituted by cardiac asymptomatic individuals, LV diastolic dysfunction and LV global longitudinal strain were impaired in 22% and 40%, respectively. These echocardiographic parameters revealed to be related to serum ferritin levels.

P1373 Cardiac source of embolism diagnosed by transeophageal echocardiography - what to expect in nowadays clinical practice

Background

Transeophageal echocardiography (TEE) is an essential tool to diagnose cardiac source of embolism (CSE) and to define treatment approach. Purpose: To review the identified CSE in 25 years experience in TEE at a tertiary centre. Methods: Retrospective study of consecutive patients (pts) who underwent TEE to search for CSE, from 1994 to 2019. Results: 2936 pts (55% males, mean age 53 ± 13 years). Ischemic cerebral event (96%) was the main location of embolism. TEE identified potential CSE in 41.5% and 7% had more than one diagnostic. The most frequent CSE were patnt foramen ovale (PFO) (16.3%) and atrial septal aneurysm (ASA), among these 65% had concomitant PFO or atrial septal defect (ASD) (14.1%). Aortic plaques ≥ 4mm were noted in 9.6%, followed by valve disease or prosthesis (5.4%), intracavitary thrombi (3.9%), vegetations (1.6%), ASD (1.5%), dilated cardiomyopathy (1.4%) and tumors (0.7%). In the last 15 years, the diagnostic effectiveness increased (35.6% vs 45.95%) and there was a shift in etiologies with an increased in the diagnose of PFO/ASD (26.8% vs 38.5%) and valve disease or prosthesis became less frequent (29.9% vs 3.7%). Overall, in elderly pts there was a preponderance of atherosclerotic plaques in the aorta, contrasting with younger pts who presented a predominance of PFO (Table1). The prevalence of spontaneous echo contrast increased with age. Pts with ischemic cerebral event were younger, mostly male and PFO was the main source of embolism (17%), while in pts with peripheral embolism the most frequent etiologies were intracavitary trombi (16%) and aortic plaques ≥ 4mm (14%). Conclusion: The main cause to perform a TEE to search for CSE was cerebral embolism, with a diagnostic effectiveness overall of 41.5%, that increased in the last 15years.

Table 1 Characteristics &lt;50 years (n = 1191) 50-75 years (n = 1569) ≥75 years (n = 171) Male (%) 601 (50%) 931 (59%) 80 (47%) Atrial septal defect (%) 23 (2%) 20 (1%) 0 Patent foramen ovale (%) 239 (20%) 226 (14%) 12 (7%) Atrial septal aneurysm (%) 70 (6%) 130 (8%) 13 (8%) Vegetations (%) 8 (0.7%) 29 (2%) 9 (5%) Tumors (%) 10 (0.8%) 8 (0.5%) 4 (2%) Intracavitary trombi (%) 28 (2%) 74 (5%) 14 (8%) Aortic plaque ≥4mm (%) 31 (3%) 203 (13%) 48 (28%) Valve disease or prothesis (%) 54 (4.5%) 109 (6%) 11 (6%) Spontaneous echo contrast (%) 36 (3%) 155 (10%) 32 (19%) Distribution of cardiac source embolism by age

Risk Prediction of Heart Failure Decompensation Events in Multiparametric Feature Spaces

Cardiac function deterioration of heart failure patients is frequently manifested by the occurrence of decompensation events. One relevant step to adequately prevent cardiovascular status degradation is to predict decompensation episodes in order to allow preventive medical interventions. In this paper we introduce a methodology with the goal of finding relevant feature spaces from multiple physiological parameters which may have predictive value in decompensation events. The best performance was obtained for the feature space comprising the following features: mean weight, standard deviation of the blood pressure and mean of extra-thoracic impedance in a time window of 20 days. Results were achieved by applying leave-one-out validation and correspond to a geometric mean of 88.32%. The obtained performance suggests that the methodology has the potential to be used in decision support solutions and assist in the prevention of this public health burden.

Dose painting by means of Monte Carlo treatment planning at the voxel level

PURPOSE

To develop a new optimization algorithm to carry out true dose painting by numbers (DPBN) planning based on full Monte Carlo (MC) calculation.

METHODS

Four configurations with different clustering of the voxel values from PET data were proposed. An optimization method at the voxel level under Lineal Programming (LP) formulation was used for an inverse planning and implemented in CARMEN, an in-house Monte Carlo treatment planning system.

RESULTS

Beamlet solutions fulfilled the objectives and did not show significant differences between the different configurations. More differences were observed between the segment solutions. The plan for the dose prescription map without clustering was the better solution.

CONCLUSIONS

LP optimization at voxel level without dose-volume restrictions can carry out true DPBN planning with the MC accuracy.

Detection of different types of noise in lung sounds

Lung sound signal processing has proven to be a great improvement to the traditional acoustic interpretation of lung sounds. However, that analysis can be seriously hindered by the presence of different types of noise originated in the acquisition environment or caused by physiological processes. Consequently, the diagnostic accuracy of pulmonary diseases can be severely affected, especially if the implementation of telemonitoring systems is considered. The present study is focused on the implementation of an algorithm able to identify noisy periods, either voluntarily (vocalizations, chest movement and background voices) or involuntarily produced during acquisitions of lung sounds. The developed approach also had to deal with the presence of simulated cough events, that carry important diagnostic information regarding several pulmonary diseases. Features such as Katz fractal dimension, Teager-Kaiser energy operator and normalized mutual information, were extracted from the time domain of healthy and a pathological lung signals. Noise detection was the result of a good discrimination between uncontaminated lung sounds and both cough and noise episodes and a slightly worse classification of cough events. In fact, detection of cough periods carrying diagnostic information was influenced by the presence of two other types of noise having similar signal characteristics.

MCTP system model based on linear programming optimization of apertures obtained from sequencing patient image data maps

PURPOSE

The authors present a hybrid direct multileaf collimator (MLC) aperture optimization model exclusively based on sequencing of patient imaging data to be implemented on a Monte Carlo treatment planning system (MC-TPS) to allow the explicit radiation transport simulation of advanced radiotherapy treatments with optimal results in efficient times for clinical practice.

METHODS

The planning system (called CARMEN) is a full MC-TPS, controlled through aMATLAB interface, which is based on the sequencing of a novel map, called "biophysical" map, which is generated from enhanced image data of patients to achieve a set of segments actually deliverable. In order to reduce the required computation time, the conventional fluence map has been replaced by the biophysical map which is sequenced to provide direct apertures that will later be weighted by means of an optimization algorithm based on linear programming. A ray-casting algorithm throughout the patient CT assembles information about the found structures, the mass thickness crossed, as well as PET values. Data are recorded to generate a biophysical map for each gantry angle. These maps are the input files for a home-made sequencer developed to take into account the interactions of photons and electrons with the MLC. For each linac (Axesse of Elekta and Primus of Siemens) and energy beam studied (6, 9, 12, 15 MeV and 6 MV), phase space files were simulated with the EGSnrc/BEAMnrc code. The dose calculation in patient was carried out with the BEAMDOSE code. This code is a modified version of EGSnrc/DOSXYZnrc able to calculate the beamlet dose in order to combine them with different weights during the optimization process.

RESULTS

Three complex radiotherapy treatments were selected to check the reliability of CARMEN in situations where the MC calculation can offer an added value: A head-and-neck case (Case I) with three targets delineated on PET/CT images and a demanding dose-escalation; a partial breast irradiation case (Case II) solved with photon and electron modulated beams (IMRT + MERT); and a prostatic bed case (Case III) with a pronounced concave-shaped PTV by using volumetric modulated arc therapy. In the three cases, the required target prescription doses and constraints on organs at risk were fulfilled in a short enough time to allow routine clinical implementation. The quality assurance protocol followed to check CARMEN system showed a high agreement with the experimental measurements.

CONCLUSIONS

A Monte Carlo treatment planning model exclusively based on maps performed from patient imaging data has been presented. The sequencing of these maps allows obtaining deliverable apertures which are weighted for modulation under a linear programming formulation. The model is able to solve complex radiotherapy treatments with high accuracy in an efficient computation time.

Dosimetric effect by shallow air cavities in high energy electron beams

This study evaluates the dosimetric impact caused by an air cavity located at 2 mm depth from the top surface in a PMMA phantom irradiated by electron beams produced by a Siemens Primus linear accelerator. A systematic evaluation of the effect related to the cavity area and thickness as well as to the electron beam energy was performed by using Monte Carlo simulations (EGSnrc code), Pencil Beam algorithm and Gafchromic EBT2 films. A home-PMMA phantom with the same geometry as the simulated one was specifically constructed for the measurements. Our results indicate that the presence of the cavity causes an increase (up to 70%) of the dose maximum value as well as a shift forward of the position of the depth-dose curve, compared to the homogeneous one. Pronounced dose discontinuities in the regions close to the lateral cavity edges are observed. The shape and magnitude of these discontinuities change with the dimension of the cavity. It is also found that the cavity effect is more pronounced (6%) for the 12 MeV electron beam and the presence of cavities with large thickness and small area introduces more significant variations (up to 70%) on the depth-dose curves. Overall, the Gafchromic EBT2 film measurements were found in agreement within 3% with Monte Carlo calculations and predict well the fine details of the dosimetric change near the cavity interface. The Pencil Beam calculations underestimate the dose up to 40% compared to Monte Carlo simulations; in particular for the largest cavity thickness (2.8 cm).

[Changes in the fat composition and histomorphology of the liver in TPN, with and without ultra-short bowel]

BACKGROUND & AIMS

Short Bowel syndrome is a serious intestinal insufficiency. The most common etiology in adults nowadays is intestinal ischemia and inflammatory disease, while in children the most common are congenital anomalies, volvolus and necrotizing enterocolaitis, which makes the TPN obligatory. However the intestine is intimately related to the liver through the entero-hepatic circulation and different endocrinological entero-hepatic systems. Massive intestinal resections and TPN would alter this relationship, and could change the hepatic tissue composition and its histomorphology. The aim of this work is to know these changes in more detail.

MATERIALS AND METHODS

We used 3 experimental groups: Group A (10 guinea pigs), which was given anesthetic and a simple laparotomy and fed for 10 days with NPT. Group B (10 guinea pigs), underwent total thin intestine resection and were fed for 10 days with NTP. The control group (6 guinea pigs) underwent anesthetic and a simple sham laparotomy and were fed orally. After this period blood and hepatic tissue samples were taken in order to study the liver fat (total fat, proportion of neutral and polar lipids, proportion of phospholipids and fatty acids). Liver biopsies were taken and studied under an optical microscope.

RESULTS

The animals from group A and B, underwent NPT, showed a significant increase in glycemie and serum triglycerides, decreasing the cholesterol in GB. There was a significant decrease in weight and in the proportion of fat per g of the liver tissue, at a maximum level in GB, and an even higher decrease in the LP/LN ratio in GA and GB. There was also a change in the proportion of phospholipids, decreasing the Phosphatidilinositol and increasing the Phosphatidiletanolamine. There was also a decrease in the AG w6/w3 ratio. Histologically appear a steatohepatitys, with a striking decrease in the mitochondrial density, being more intensive in GB.

CONCLUSIONS

NPT alters the composition of the hepatic fat and the hystomorphology of the liver. The short bowel syndrome have more lesional mechanisms, favouring the hepatic damage caused by NPT.

Hypertensive disorders in pregnancy: screening by uterine artery Doppler imaging and blood pressure at 11-13 weeks

OBJECTIVES

To examine the performance of screening for hypertensive disorders in pregnancy at 11-13 weeks by a combination of the maternal history, uterine artery Doppler imaging and blood pressure.

METHODS

This was a prospective screening study for pre-eclampsia (PE) requiring delivery before 34 weeks (early PE), late PE and gestational hypertension (GH) in women attending for their routine first hospital visit in pregnancy at 11 + 0 to 13 + 6 weeks of gestation. Maternal history was recorded, color flow Doppler imaging was used to identify the uterine artery with the lowest pulsatility index (L-PI) and automated devices were used to measure the mean arterial pressure (MAP). The performance of screening for PE and GH by a combination of the maternal factor-derived a-priori risk, the uterine artery L-PI and MAP was determined.

RESULTS

There were 8061 (96.4%) cases unaffected by PE or GH, 165 (2.0%) that developed PE including 37 that required delivery before 34 weeks (early PE) and 128 with late PE, and 140 (1.7%) that developed GH. The MAP was higher in early PE, late PE and GH than in the unaffected group (P < 0.0001), and in early PE than in GH (P = 0.002). The uterine artery L-PI was significantly higher in early PE and late PE than in the unaffected group (P < 0.0001), in early PE than late PE or GH (P < 0.0001), and in GH than in the unaffected group (P = 0.014). In screening by a combination of the maternal factor-derived a-priori risk, uterine artery L-PI and MAP, the estimated detection rate at a 10% false-positive rate was 89.2% (95% CI, 74.6-96.9%) for early PE, 57.0% (95% CI, 48.0-65.7%) for late PE and 50.0% (95% CI, 41.4-58.6%) for GH.

CONCLUSIONS

Effective screening for hypertensive disorders in pregnancy is provided by a combination of maternal history, uterine artery Doppler imaging and blood pressure at 11-13 weeks.

Relationship of stem water potential and leaf conductance to vegetative growth of young olive trees in a hedgerow orchard

In 2005, four irrigation treatments were applied to a 3-year-old cv. Cornicabra orchard. In T1, wetted soil volume was maintained close to field capacity by irrigating when soil sensors indicated that soil water potential in the root zone had fallen to –0.03 MPa and 0.06 MPa from spring until 15 August and from 15 August until September, respectively. On those days, 8, 6, 4, and 2 h of irrigation was applied to T1, T2, T3, and T4, so that over the season they received 106, 81, 76 and 31 mm of irrigation, respectively. The high value for T3 was the result of a valve failure on 13 June. Measurements were maintained throughout the experimental period of relative extractable water (REW) to 1 m depth at the wetted volume (0.30 m from a drip emitter), shoot length, trunk diameter, stem water potential (Ψstem) and leaf conductance (gl). The irrigation treatment significantly affected REW (P < 0.10), Ψstem, gl and vegetative growth (P < 0.05). Ψstem, and trunk diameter were the least variable parameters and Ψstem and shoot growth were the most sensitive to water stress. Although T1 received 24% more water than T2, no significant differences were detected in vegetative growth. T2 should be considered the optimum irrigation value. The mean monthly Kc for T2 was 0.086. The failure of the valve in T3 simulated a wet spring followed by limited irrigation. Irrigation applied was similar to T2 but shoot growth stopped one month earlier and lower values of Ψstem and gl were observed after mid August. REW was highly related to vegetative growth, 66% of maximum being achieved at REW 0.53 and 50% at 0.45. gl was independant of plant or soil water status and did not determine vegetative growth. A strong relationship established Ψstem as a good indicator of vegetative growth and hence of water stress. Shoot growth was 66% of maximum at Ψstem –1.5 MPa and 50% at –1.8 MPa.

The change of response of ionization chambers in the penumbra and transmission regions: impact for IMRT verification

Significant deviations from the expected dose have been reported in the absolute dosimetry validation of an intensity modulated radiation therapy treatment when individual segments are analyzed. However, when full treatment is considered and all segment doses are added together, these discrepancies fade out, leading to overall dose deviations below a 5% action level. This contradictory behavior may be caused by a partial compensation between detector over-responding and under-responding for measurement conditions far from radiation equilibrium. We consider three treatment verification scenarios that may lead to ionization chamber miss-responding, namely: narrow beam irradiation, field penumbra location and multi-leaf collimator transmission contribution. In this work we have analyzed the response of three different ionization chambers with different active volume under these conditions by means of Monte Carlo (MC) simulation methods. Correction factors needed to convert the detector readout into actual dose to water were calculated by inserting the specific detector geometry (carefully modeled) into the simulations. This procedure required extensive use of parallel computing resources in order to achieve the desired level of uncertainty in the final results. The analysis of the simulations shows the relative contribution of each of the three previously mentioned miss-responding scenarios. Additionally, we provide some evidence on dose deviation compensation in multi-segment radiotherapy treatment verification.

Early hyponatraemia after pituitary surgery: cerebral salt-wasting syndrome

Hyponatraemia is a common complication in patients undergoing neurosurgery. It can be caused either by the syndrome of inappropriate secretion of antidiuretic hormone or by the cerebral salt-wasting syndrome (CSWS). CSWS frequently occurs in patients suffering from subarachnoid haemorrhage and brain injury, but it is rare after pituitary tumour surgery. However, this diagnostic possibility should be considered as these disorders require specific treatment and have different prognoses. In this article, we present a case of acute and early hyponatraemia caused by CSWS after pituitary tumour surgery. We also revise the aetiology, mechanisms, differential diagnosis and treatment of hyponatraemia after pituitary surgery.

Quality-of-life measurement in patients with inflammatory bowel disease receiving social support

BACKGROUND

Crohn's disease and ulcerative colitis, referred to as inflammatory bowel diseases, affect mainly young adults and have an elevated morbidity and a negative effect on quality of life. This study aimed to compare the health-related quality of life between 2 randomized groups of patients with inflammatory bowel disease: (1) the supported group (SG), patients receiving social support for an 18-month period, and (2) the control group (CG), patients receiving no social support.

METHODS

Health-related quality of life was assessed at 4 moments with the Portuguese versions of the Medical Outcomes Study Short Form 36 and the Inflammatory Bowel Disease Questionnaire (IBDQ), both validated in Brazil.

RESULTS

In the SG, using analysis of variance for repeated measures complemented by the Bonferroni test positive variations were observed (1) in the Social Aspects domain, between the first and third evaluations (P = 0.044), and (2) in the Emotional Aspects domain, between the first and second and the third and fourth evaluations (P = 0.029).

CONCLUSIONS

In the sample studied, social support, measured by use of the Inflammatory Bowel Disease Questionnaire, had a positive impact on the social and emotional aspects of quality of life.

Characterization of megavoltage electron beams delivered through a photon multi-leaf collimator (pMLC)

A study is presented that characterizes megavoltage electron beams delivered through an existing double-focused photon multi-leaf collimator (pMLC) using film measurements in a solid water phantom. Machine output stability and linearity were evaluated as well as the effect of source-to-surface distance (SSD) and field size on the penumbra for electron energies between 6 and 18 MeV over an SSD range of 60-100 cm. Penumbra variations as a function of field size, depth of measurement and the influence of the jaws were also studied. Field abutment, field flatness and target coverage for segmented beams were also addressed. The measured field size for electrons transported through the pMLC was the same as that for an x-ray beam up to SSDs of 70 cm. At larger SSD, the lower energy electron fields deviated from the projected field. Penumbra data indicated that 60 cm SSD was the most favourable treatment distance. Backprojection of P(20-80) penumbra data yielded a virtual source position located at 98.9 cm from the surface for 18 MeV electrons. For 6 MeV electrons, the virtual source position was at a distance of 82.6 cm. Penumbra values were smaller for small beam slits and reached a near-constant value for field widths larger than 5 cm. The influence of the jaws had a small effect on the penumbra. The R90 values ranged from 1.4 to 4.8 cm between 6 and 21 MeV as measured at 60 cm SSD for a 9 x 9 cm2 field. Uniformity and penumbra improvement could be demonstrated using weighted abutted fields especially useful for small segments. No detectable electron leakage through the pMLC was observed. Bremsstrahlung measurements taken at 60 cm SSD for a 9 x 9 cm2 field as shaped by the pMLC compared within 1% to bremsstrahlung measurements taken at 100 cm SSD for a 10 x 10 cm2 electron applicator field at 100 cm SSD.

Evaluative and Discriminative Properties of the Portuguese MacNew Heart Disease Health-related Quality of Life Questionnaire

The aim of this study was to validate the Portuguese version of the self-administered MacNew Heart Disease Health-related Quality of Life (MacNew) questionnaire in patients after diagnosis of acute coronary syndrome. The MacNew, with a Global score and physical, emotional and social subscales, the Short Form SF-36 (SF-36) and the Hospital Anxiety and Depression Scale (HADS) were completed at baseline by 150 patients and again by 48 clinically stable patients 2-3 weeks later. A cohort of 50 different patients completed the same questionnaires before and after a cardiac rehabilitation program in order to examine responsiveness. Acceptance of the MacNew by the patients was good and the three factor model was substantiated and explained 52.2% of the variance. Internal consistency, intra-class-correlation, and test-retest reliability each exceeded 0.72. The predicted construct validity hypotheses were partially confirmed. The discriminative validity of the MacNew was confirmed with significantly higher MacNew scores for patients with normal left ventricular function, with improved health status, and who were not anxious or depressed. Even though MacNew scores improved significantly following cardiac rehabilitation, the evaluative validity of the MacNew was less robust with small responsiveness statistics. The Portuguese version of the MacNew HRQL questionnaire appears to be a reliable, valid, and moderately responsive instrument to evaluate health-related quality of life after diagnosis of acute coronary syndrome.

Healthcare resource utilization during 1-year treatment with long-acting, injectable risperidone

BACKGROUND

Schizophrenia is associated with disproportionately high costs, mainly due to hospitalization rates. This study assessed healthcare resource use in patients with schizophrenia and schizoaffective disorder during treatment with long-acting risperidone.

METHODS

Patients (n = 397 [inpatients, 24%; outpatients, 76%]) receiving stable doses of an antipsychotic for >or=4 weeks were eligible to enter this 1-year, open-label study. Following a 2-week run-in period (oral risperidone 1-6 mg/day), patients received intramuscular long-acting risperidone (25 or 50 mg modal dose) every 2 weeks. Healthcare resource use in the previous 12 weeks was assessed at baseline and 12-weekly intervals.

RESULTS

Patients needing hospitalization decreased significantly and continuously from 38% during the 12 weeks before study entry to 12% during the last 12 weeks. Mean hospitalization length during the study was 30.5 days (outpatients, 4.9 days; inpatients, 110 days). This included 28 patients (7%) who remained in hospital throughout the study. During treatment, 71% of those hospitalized at baseline were discharged. Partial hospitalization decreased significantly from 7% of patients during the 12 weeks before treatment to 3% during the last 12 weeks. Outpatient consultations also decreased significantly from 70% of patients to 30% in the first 12 weeks of treatment and remained stable thereafter. Only 9% of patients required an emergency room visit; mostly for non-psychiatric conditions.

CONCLUSION

Healthcare resource use is significantly reduced in patients with stable schizophrenia or schizoaffective disorder receiving long-acting risperidone. It is highly likely that these reductions will decrease healthcare costs in patients receiving long-acting risperidone.

Ionization chamber dosimetry of small photon fields: a Monte Carlo study on stopping-power ratios for radiosurgery and IMRT beams

Absolute dosimetry with ionization chambers of the narrow photon fields used in stereotactic techniques and IMRT beamlets is constrained by lack of electron equilibrium in the radiation field. It is questionable that stopping-power ratio in dosimetry protocols, obtained for broad photon beams and quasi-electron equilibrium conditions, can be used in the dosimetry of narrow fields while keeping the uncertainty at the same level as for the broad beams used in accelerator calibrations. Monte Carlo simulations have been performed for two 6 MV clinical accelerators (Elekta SL-18 and Siemens Mevatron Primus), equipped with radiosurgery applicators and MLC. Narrow circular and Z-shaped on-axis and off-axis fields, as well as broad IMRT configured beams, have been simulated together with reference 10 x 10 cm2 beams. Phase-space data have been used to generate 3D dose distributions which have been compared satisfactorily with experimental profiles (ion chamber, diodes and film). Photon and electron spectra at various depths in water have been calculated, followed by Spencer-Attix (delta = 10 keV) stopping-power ratio calculations which have been compared to those used in the IAEA TRS-398 code of practice. For water/air and PMMA/air stopping-power ratios, agreements within 0.1% have been obtained for the 10 x 10 cm2 fields. For radiosurgery applicators and narrow MLC beams, the calculated s(w,air) values agree with the reference within +/-0.3%, well within the estimated standard uncertainty of the reference stopping-power ratios (0.5%). Ionization chamber dosimetry of narrow beams at the photon qualities used in this work (6 MV) can therefore be based on stopping-power ratios data in dosimetry protocols. For a modulated 6 MV broad beam used in clinical IMRT, s(w,air) agrees within 0.1% with the value for 10 x 10 cm2, confirming that at low energies IMRT absolute dosimetry can also be based on data for open reference fields. At higher energies (24 MV) the difference in s(w,air) was up to 1.1%, indicating that the use of protocol data for narrow beams in such cases is less accurate than at low energies, and detailed calculations of the dosimetry parameters involved should be performed if similar accuracy to that of 6 MV is sought.

A single growth hormone (GH) determination is sufficient for the diagnosis of GH-deficiency in adult patients using the growth hormone releasing hormone plus growth hormone releasing peptide-6 test

BACKGROUND

The diagnosis of GH deficiency in adults is based on the provocative testing of GH secretion. When testing a patient with suspected GH deficiency, clinicians assess the whole secretory curve and select the GH peak as an index of secretory capability. This procedure is time consuming and the determination of GH in several samples is necessary. The combined administration of growth hormone releasing hormone (GHRH) plus growth hormone releasing peptide-6 (GHRP-6) is an effective test of GH secretion, and it has been unambiguously demonstrated that the elicited GH peak is capable of segregating normal GH secretion subjects from GH deficient patients on an individual basis. The GHRH + GHRP-6 test biochemically classifies patients into three groups; those with a stimulated GH peak >/= 20 micro g/l are considered normal and those with peaks at </= 10 micro g/l as GH deficient. The group comprising individuals between these parameters is considered uncertain, and the results are further interpreted according to clinical information, or by other tests.

OBJECTIVE

As the GHRH + GHRP-6 test induces GH peaks consistently in the first 30 minutes, the working hypothesis assessed in this study was whether a single determination of GH 30 minutes after stimulus could provide the same clinical classification as the whole secretory curve.

PATIENTS AND METHODS

Three hundred and forty-nine adult subjects (146 patients with organic pituitary disease and 203 healthy subjects) were studied. All were administered GHRH 1 micro g/kg i.v. plus GHRP-6 1 micro g/kg i.v. at 0 minutes, and blood samples were obtained at regular intervals. GH was determined in all samples.

RESULTS

GHRH + GHRP-6-evoked GH peaks in controls and patients were not correlated with GH basal values, making this determination useless for test validation. In contrast, an excellent correlation was observed between GH values at 30 minutes and the GH peaks (r = 0.994, P < 0.0001). When comparing the 30-minute GH values against the peaks, the biochemical classification changed from normal toward uncertain in only five out of 203 control subjects, which is without clinical relevance according to Bayes theorem. Similarly, when the 30-minute value was used instead of the peak in GH deficient patients, only two out of 146 patients moved from the uncertain area toward the GH deficient one. Thus, better diagnostic classification was provided for patients.

CONCLUSIONS

The GHRH + GHRP-6 test is a convenient, safe and reliable, provocative test of GH reserve in adults, which can be reduced to a single fixed GH determination 30 minutes after stimulus.

Actions of activins, inhibins and follistatins: implications in anterior pituitary function

1. The anterior pituitary is well documented to be under the control of central and peripheral factors that dynamically interact to affect cell-specific modulation of pituitary functions. However, it is becoming increasingly evident that these extrinsic factors work in concert with a variety of local products that exert autocrine/paracrine control on pituitary cells. 2. These factors modulate the activity of their target pituitary cells by altering the synthesis and secretion of cell-specific hormones and by exerting control on the growth and differentiation of cells of this tissue. Included in the list of growth factors and bioactive peptides known to be products of pituitary cells are the activins, possibly inhibins and follistatins. 3. These protein factors play an important role in the local modulation of several pituitary cell types and are crucial for the maintenance of normal follicle-stimulating hormone production and, thus, reproductive function and fertility.