P5740ACE2 activity level is associated with embolic stroke of undetermined source

Background

ACE2 activity levels correlate with adverse left atrial remodelling in patients with atrial fibrillation (AF). Several biochemical and structural markers have been associated with embolic stroke of undetermined source (ESUS). The relationship between ACE2 activity and ESUS is unknown.

Purpose

Randomised controlled trials failed to demonstrate a clear benefit of oral anticoagulation in an unselected ESUS population. As selective use of oral anticoagulation guided by biomarker risk-profiling may benefit these patients, we evaluated the association between ACE2 activity and ESUS.

Methods

This prospective case control study compared patients with ESUS against a control group matched for vascular risk factors. ESUS was diagnosed following cerebral vascular imaging and 24 hours of cardiac monitoring to exclude AF. Blood samples were collected for measurement of ACE2 activity, D-Dimer and high sensitivity troponin T (hsTnT).

Results

A total of 51 patients in the ESUS group were compared with 47 patients in the Control group. ACE2 activity and D-Dimer levels were significantly higher in the ESUS group. There was a significant but weak positive correlation between ACE2 activity and hsTnT (r=0.20, p<0.05). Left atrial volume index (LAVI) on echocardiography was significantly higher in the ESUS group. On regression modelling adjusting for LAVI, only ACE2 activity remained significant for ESUS, with a 20% rise in odds for every 4 unit increase in ACE2 activity (OR 1.20; 95% CI: 1.01 - 1.36, p=0.04).

Participant characteristics Control (n=47) ESUS (n=51) P value Age (years) 65.65±6.78 67.20±6.89 0.26 Female gender 22 (45.8) 19 (38.0) 0.43 Hypertension 22 (45.8) 24 (48.0) 0.83 Diabetes mellitus 9 (18.8) 12 (24.0) 0.53 CHA2DS2VASc score 2 (1–3) 2 (1–3) 0.50 LA size & Biomarkers   LA volume index (ml/m2) 36.5 (32.6–42.5) 39.1 (36.2–46.0) 0.04   ACE2 (pmol/ml/min) 7.24 (2.66–14.64) 10.16 (4.54–18.80) 0.04   D-Dimer (mg/L) 0.35 (0.3–0.5) 0.40 (0.30–0.60) 0.02   hsTroponin T (ng/L) 7.0 (5–10) 9.00 (6.0–13.5) 0.05 Values are expressed as mean ± standard deviation, median (IQR), or n (%).

Median ACE2 activity

Conclusion(s)

ACE2 activity is associated with ESUS independent of left atrial volume and correlate with elevated Troponin. Further studies are warranted to investigate the utility of ACE2 activity in identifying ESUS patients that may benefit from oral anticoagulation.

Acknowledgement/Funding

This study received project funding from the Eastern Health Foundation

Large left ventricular metastasis causing left ventricular outflow tract obstruction and haemolysis

Although post-mortem studies would suggest that cardiac metastases occur frequently, many of these metastases remain clinically silent. However, symptomatic lesions may also remain unrecognized due to overshadowing by other symptoms of the primary malignancy. Patients undergoing treatment for cancer are not routinely screened using echocardiography, unless their chemotherapeutic regimen includes cardiotoxic agents. The current era of research and development of targeted biological agents (such as trastuzumab and epidermal growth factor receptor inhibitors) for cancer may lead to prolonged survival of oncology patients. In future, metastases that were once rare may become increasingly recognized as these new treatments augment the natural history of the disease. There have been several case reports of small, asymptomatic left ventricular metastases, but clinically significant ventricular metastases are very rare. There are no reports in the current literature of a symptomatic ventricular metastasis, occurring in the absence of other metastatic disease. We report an unusual case of a large solitary ventricular metastasis, leading to left ventricular outflow tract obstruction and haemodynamic compromise. Echocardiographic imaging led to the diagnosis of a recurrence of soft-tissue fibrosarcoma 9 years after original resection.

Effect of harmonic imaging on the measurement of ultrasonic integrated backscatter and its interpretation in patients following myocardial infarction

BACKGROUND

Recently, we have demonstrated that cyclic variation in ultrasonic integrated backscatter (IBS) can be used to predict patency of the infarct related artery (IRA) post-acute myocardial infarction (AMI). Second harmonic imaging has become widely available on ultrasound machines and enhances endocardial definition. The effect of harmonic imaging on the measurement and interpretation of cyclic IBS is unknown.

METHODS AND RESULTS

Twenty-eight patients were studied post-AMI. Cyclic IBS was measured in myocardial segments supplied by the IRA as well as in remote segments with normal myocardial function in both fundamental and second harmonic modes. Harmonic imaging increased the measurement of cyclic IBS in IRA as well as normal myocardial territories. However, the difference in cyclic IBS between IRA and normal myocardial territories remained unchanged.

CONCLUSION

Second harmonic imaging increases the measurement of cyclic IBS. However, the interpretation of these data is unchanged in the setting of AMI. It is important that repeated studies in the same patient are performed in the same mode (fundamental or harmonic) as the values are not interchangeable.

Determination of successful reperfusion after thrombolysis for acute myocardial infarction: a noninvasive method using ultrasonic tissue characterization that can be applied clinically

BACKGROUND

The aim of the present study was to determine the use of cyclic variation in ultrasonic integrated backscatter (IBS), which is reduced in ischemic myocardium, to predict an occluded infarct-related artery (IRA) after thrombolysis for acute myocardial infarction (AMI). This is important, because patency of the IRA 90 minutes after thrombolysis has been shown to predict outcome.

METHODS AND RESULTS

One hundred thirteen patients with AMI had peak-to-peak cyclic IBS measured in the myocardial territory supplied by their IRA as well as a remote territory with normal function from the parasternal long- or short-axis view. This analysis took 5 to 10 minutes. Wall motion score index was assessed, and coronary angiography, to determine patency of the IRA, was performed in all patients. Cyclic IBS in the IRA territory was much lower in segments supplied by an occluded IRA (3.3 versus 4.6 dB, P<0.00001). Using a difference in cyclic IBS between infarcted and normal segments of 15% (or 1.5 dB) as a cutoff, the sensitivity, specificity, positive and negative predictive values to determine an occluded IRA were 92%, 75%, 81%, and 89%, respectively.

CONCLUSIONS

The difference in cyclic IBS between IRA and remote normal segments, which can be analyzed rapidly, can be used to predict patency of the IRA in patients with AMI. This provides a noninvasive method to determine those patients who may require urgent invasive investigation.

Echocardiologists' role in the deployment of the Amplatzer atrial septal occluder device in adults

Use of the Amplatzer Septal Occluder device to close selected secundum atrial septal defects is ever-increasing. This article illustrates the central role of the echocardiologist before, during, and after percatheter closure with the Amplatzer Septal Occluder device. Figures, diagrams, and tables detail each stage of the evaluation, procedure, and postprocedural assessment.

Cobrahead malformation of the Amplatzer septal occluder device: an avoidable compilation of percutaneous ASD closure

During deployment of an Amplatzer atrial septal occluder device to close a secundum ASD, the right atrial disk and waist of the device twisted, resulting in the cobrahead malformation. Postulated mechanisms for this complication include twisting of the device during loading into the delivery catheter and catching of leading edge of the device on the LA free wall or appendage, causing twisting during deployment. Retrieval of the device into the catheter and even removal of the device from the patient to allow manual untwisting may be required to allow the device to return to its original conformation for successful redeployment.

Thrombus on an ASD closure device: A call for caution

Use of per-catheter atrial septal defect closure devices is becoming increasingly widespread. We report a case of left atrial thrombus formation on a StarFLEX device raising concerns regarding the general use of these devices and as a means of preventing paracloxical embolism in particular.

Forensic echocardiography: a case in point

Transthoracic echocardiography (TTE) has an important role in the assessment of patients with acute penetrating chest trauma. We report the case of a 36-year-old man who sustained a stab wound to the chest. After admission, he required emergency pericardiocentesis. TTE revealed a traumatic ventricular septal defect and a defect in the anterior mitral valve leaflet. To assess whether these lesions were related to the initial stab wound or the pericardiocentesis, the transducer was positioned over the stab wound, and the lesions were shown to be in the same plane as the entry site, thus ruling out iatrogenic trauma.

Chiari network entanglement and herniation into the left atrium by an atrial septal defect occluder device

The Chiari network is a fenestrated membrane consisting of threads and strands in the right atrium. First described in 1897 by anatomist Hans Chiari, it is a congenital remnant of embryonic development resulting from incomplete resorption of the right valve of the sinus venosus. Found in 2% to 3% of the population, it is generally not of clinical importance. Rarely, however, the network may be associated with serious complications such as thrombus formation, embolus entrapment, arrhythmia, tumor development, and catheter entrapment. We report the entanglement of an Amplatzer septal occluder device catheter in a prominent Chiari network that was herniated into the left atrium. Transesophageal echocardiographic recognition of this before deployment and guidance during disentanglement is described below.

Mycotic dermatitis in an Atlantic white-sided dolphin, a pygmy sperm whale, and two harbor seals

An Atlantic white-sided dolphin (Lagenorhynchus acutus), a pygmy sperm whale (Kogia breviceps), 2 harbor seals (Phoca vitulina) developed raised, firm, erythematous, cutaneous nodules that were most prominent on their heads, trunks, and on the caudal portions of their bodies. Prior to the onset of the condition, all 4 animals may have been stressed by factors such as being stranded on a beach, being transported long distances, or being relocated locally. Microbial culturing of the lesions on multiple media yielded fungal isolates containing conidia characteristic of Fusarium spp. Hyphae consistent with those of an ascomycete were evident on histologic examination of lesions. In each treated animal, the dermatitis resolved 3 to 4 weeks after completing treatment with ketoconazole. Fusarium spp may be opportunistic invaders of the skin of marine mammals that have decreased immunocompetence or integumentary compromise.

Clinical effects of buspirone on intractable self-injury in adults with mental retardation

OBJECTIVE

The efficacy of buspirone in controlling self-injurious behavior was examined in five individuals with mental retardation. Buspirone was used alone in two individuals and as an adjunct to thioridazine in the other three.

METHOD

Standard behavioral observation methods were used to collect data on the number of self-injurious responses of the individuals during baseline and several doses of buspirone in an open trial.

RESULTS

When compared with baseline levels, all five individuals showed some response to buspirone, with reductions in self-injury ranging from 13% to 72%, depending on the dose. The most effective dose of buspirone was 30 mg/day for three individuals and 52.5 mg/day for the other two. These individuals were maintained for 6 to 33 weeks on their most effective dose. Coexistent symptoms of anxiety did not predict a favorable response to buspirone therapy.

CONCLUSIONS

Buspirone showed a mixed but generally favorable response in controlling intractable self-injury in this and four previous studies reporting similar cases. However, the drug should not be endorsed as a proved treatment for self-injury until similar results have been obtained from well-controlled studies of its efficacy.

Fluoxetine treatment of severe self-injury in young adults with mental retardation

Dysfunction of the serotonergic system has been implicated in the development and maintenance of self-injury in some persons with mental retardation. Several preliminary reports have suggested that fluoxetine, a drug that blocks the reuptake of serotonin, may decrease self-injury in these individuals. Of the 44 cases of self-injury treated with fluoxetine and previously reported in the literature, 42 demonstrated a beneficial response to the drug. We report four additional cases of adults with mental retardation whose self-injury was treated with fluoxetine. Each of these individuals benefited from fluoxetine to some extent, with average decreases in self-injury ranging from 20% to 88% when compared with baseline levels. These findings, combined with those from previously published case studies, emphasize the need for well-controlled studies to more adequately assess the effects of fluoxetine on self-injury.

Simultaneous tracheobronchial and esophageal obstruction caused by a descending thoracic aneurysm

Descending thoracic aortic aneurysms are a rare cause of symptomatic airway or esophageal obstruction. We report the case of a patient with simultaneous severe dyspnea and dysphagia from the thoracic portion of a thoracoabdominal aortic aneurysm. Perioperative management of the airway obstruction was an essential component of successful treatment. Repair of the aneurysm resulted in resolution of the patient's symptoms.

Comparison of thin section computed tomography with bronchography for identifying bronchiectatic segments in patients with chronic sputum production

Computed tomography is widely used in the investigation of patients in whom bronchiectasis is suspected, despite considerable variation in its reported sensitivity and specificity. The findings with 3 mm high resolution computed tomography were compared at segmental level with bronchography by two radiologists independently in 27 patients (aged 20-67 years) undergoing investigation of chronic sputum production. Fifteen patients were found to have bronchiectasis by both investigations. Five were identified by computed tomography alone, including two in whom disease was revealed in segments underfilled at bronchography. The sensitivity of computed tomography compared with bronchography in the diagnosis of bronchiectasis at segmental level was 84% and the specificity 82%. The predictive value of computed tomography in the diagnosis of bronchiectasis was 38% overall, but increased to 75% when only those segmental bronchi moderately or severely dilated on the computed tomography scan were considered. There was no relation between the degree of bronchial wall thickening on the computed tomogram and the diagnosis of bronchiectasis by bronchography. Bronchography may be avoided in patients being considered for surgical resection of their bronchiectasis in whom computed tomography shows diffuse disease.

The impact of computed tomography and ultrasonography on the management of patients with carcinoma of the ovary

We have carried out a prospective study on the impact of computed tomography (CT) and ultrasonography (US) on the management of patients with carcinoma of the ovary. Seventy-eight CT and 88 US scans were performed on 94 patients. Clinicians decided patient management prospectively at the time the CT and/or US was ordered. Clinical assessment differed from the result obtained by CT or US in 45% of cases (35/78 and 40/88, respectively). CT and US altered patient management in only a minority of cases (14/78, 18% and 9/88, 10% respectively). Even when the scan and clinical assessments differed, management was only altered on 14/35 (40%) occasions after CT and on 9/40 (23%) occasions after US, a difference which was not significant. In patients with clinically undetectable disease, management was altered by CT on 17% of occasions and by US on 10%. We conclude that in patients with carcinoma of the ovary CT and US alters patient management in a minority of cases. In view of current financial restrictions in health care, clinicians should be more selective in the use of these imaging techniques. Furthermore, we recommend that similar prospective studies are performed for other clinical situations.

A comparison between pancreas and heart allotransplantation after administration of donor-specific antigen and cyclosporine

These experiments compared the effect of a five-day course (days - 1 to +3) of cyclosporine therapy coupled with pretransplant (day - 1) administration of donor-specific antigen (whole blood or splenocytes) on either pancreatic or heart allograft survival in the Buffalo to Lewis rat donor-recipient combination. CsA therapy alone significantly (P less than 0.001) prolonged both heart (16.2 +/- 1.6 days) and pancreas (12.5 +/- 1.5 days) graft survival when compared with nonimmunosuppressed control heart and pancreas grafts (7.7 +/- 1.8 and 7.9 +/- 1.0 days, respectively). Pretransplant transfusion with either 2 ml of BUF whole blood or 2 x 10(8) red cell-free splenocytes on day -1 also resulted in a significant (P less than 0.001) prolongation of heart survival (14.0 +/- 1.2 and 14.0 +/- 1.6 days, respectively) but did not improve pancreas allograft survival (9.4 +/- 1.5 and 8.5 +/- 1.0 days, respectively). Combination CsA and antigen therapy further improved heart graft survival to 26.5 +/- 6.1 days (whole blood) and 28.8 +/- 5.8 days (splenocytes) but did not improve pancreas graft survival over that of CsA therapy alone. Extension of CsA therapy by adding two additional 3-day cycles on days 10-12 and 17-19 further improved heart graft survival both after CsA alone (35.2 +/- 3.2 days) and after CsA coupled with whole-blood transfusion (45.3 +/- 8.6 days), but did not have a salutary effect on pancreas allograft survival. Portal vein administration of donor antigen was equally effective as systemic inoculation in prolonging heart graft survival when the splenocytes were given alone (11.6 +/- 1.7 days). Conversely, pancreas allograft survival was not beneficially effected by portal antigen administration whether or not CsA was given. These data demonstrate the ability of pretransplant donor-specific antigen administration and short-term CsA therapy to significantly prolong rat heart allograft survival across a strong MHC histocompatibility barrier-but, surprisingly, they also demonstrate the failure of this regimen to have a salutary effect on pancreas allograft survival.

The accuracy of mammography alone and in combination with clinical examination and cytology in the detection of breast cancer

The accuracy of mammography alone and in combination with clinical examination and aspiration cytology was assessed in 402 patients who attended the Early Diagnostic Unit of the Royal Marsden Hospital, London. The sensitivities of mammography, clinical examination and cytology in identifying breast cancer were 76.9%, 81.7% and 63.5% respectively; the specificities of each test were 90.0%, 87.6% and 99.3%. The calculated sensitivity was increased to 96.2% if one positive test out of the three was regarded as an indication to undertake breast biopsy. If this approach was adopted the number of breast cancers missed would be two out of 104 and the yield of positive biopsies would be approximately one in four (27.6%). The implications of proceeding to breast biopsy on the basis of a single positive test are discussed.

A quantitative analysis of the spatial relationships of grouped microcalcifications demonstrated on xeromammography in benign and malignant breast disease

The mammograms of 444 patients who had a breast biopsy leading to a definitive histological diagnosis were reviewed. In 21 cases (4.7%) grouped microcalcifications were identified as the only mammographic abnormality. These groups of microcalcifications were analysed to determine whether there was any quantitative difference between benign and malignant lesions with respect to a shape parameter of the group, the spatial frequency of the particles and neighbour-to-neighbour relationships of the particles. This analysis did not reveal any significant difference between the spatial relationships of the grouped microcalcifications found in benign and malignant breast disease.

The supine pneumothorax

The consequences of an undiagnosed pneumothorax can be life-threatening, particularly in patients with trauma to the head or multiple injury and in those requiring mechanical ventilation. Yet it is these patients, whose films will be assessed initially by the surgeon, who are more likely to have a chest X-ray taken in the supine position. The features of supine pneumothoraces are described and discussed together with radiological techniques used to confirm the diagnosis, including computed tomography (CT) which may be of particular importance in patients with associated cranial trauma.

Role of computed tomography in diagnosis of bronchiectasis

Bronchograms and computed tomograms were performed in 27 patients who presented consecutively for bronchography with chronic sputum production. The films were reported separately by three consultant radiologists, who had been asked to give a diagnostic interpretation of the films for each bronchopulmonary segment. The reporting of bronchiectasis on computed tomograms was compared with that on bronchograms. The sensitivity and specificity of computed tomography at segmental level compared with bronchography was 66% and 92%, respectively. We conclude that computed tomography alone is not yet suitable for accurate characterisation and localisation of disease in patients in whom surgery is contemplated. Computed tomography may be useful in patients in whom bronchography is contraindicated and for monitoring progression of disease after initial combined computed tomography and bronchography.

Interpretation of bronchograms and chest radiographs in patients with chronic sputum production

Bronchograms and plain chest radiographs of 27 patients with chronic sputum production were reported separately in random order and independently by two pulmonary radiologists to establish the diagnostic rate of each investigation and to assess interobserver variation. Both radiologists agreed on the presence of bronchiectasis on bronchography in 19 of 27 (70%) patients and in 94 of 448 (21%) bronchopulmonary segments. One radiologist only interpreted the films as showing bronchiectasis in a further two (7%) patients and 26 (6%) segments. There was more disagreement about the presence or absence of individual bronchographic abnormalities. Two main groups of patients with bronchiectasis were identified by bronchography: 11 with bronchiectasis alone and eight with bronchiectasis and bronchographic features suggestive of "chronic bronchitis". There was no clinical difference between these two groups. Plain chest radiographs were insensitive, being diagnostic (both radiologists agreeing) of bronchiectasis in only nine of 19 (47%) patients with definite bronchiectasis on bronchography.

The appearances of multiple biliary hamartomas of the liver (von Meyenberg complexes) on computed tomography

Computed tomography is well established in the management of patients with malignant disease, both as a staging procedure before initiation of treatment and in follow up. The presence of unsuspected metastases may affect the decision to perform surgery on the primary tumour and may alter the management of suspected recurrent tumour. Two cases are presented of patients with primary carcinoma whose computed tomography images showed multiple focal hepatic lesions suggestive of metastases. However multiple biliary hamartomas were found on histology, in one case by biopsy and in the other at post mortem. The differential diagnosis and significance of multiple liver defects on computed tomography is considered.

Isolation of a porcine liver plasma membrane fraction that binds low density lipoproteins

Large amounts of injected radiolabeled low density lipoproteins have been found by others to accumulate primarily in the liver and studies in various types of isolated cells, including hepatocytes, have indicated the presence of specific cell membrane recognition sites for lipoproteins. In the present studies, the high affinity binding of radiolabeled low density lipoproteins ([125I]LDL, d 1.020--1.063 g/mL) was measured in the major subcellular fractions of porcine liver homogenates. The nuclear and mitochondrial fractions were 1.9- and 1.4-fold enriched in binding activity with respect to unfractionated homogenates and contained 15% and 12% of the total binding activity, respectively. The microsomes, which contained most of the plasma membranes and endoplasmic reticulum, were approximately 4-fold enriched in binding and contained 73% of the binding activity. Microsomal subfractions obtained by differential homogenization and centrifugation procedures were 5.6--7.0-fold enriched in LDL binding and contained 54--58% of the homogenate binding activity. They were separated by discontinuous sucrose density gradient centrifugation into fractions which contained "light" and "heavy" plasma membranes and endoplasmic reticulum. The heavy membrane fraction was 2--4 fold in binding with respect to the parent microsomes (16--22 fold with respect to the homogenate). There was no enrichment of binding activity in the other two fractions. Two plasma membrane "marker" enzymes, nucleotide pyrophosphatase and 5'-nucleotidase, were also followed. Of the two, binding in the sucrose density gradient subfractions most closely followed nucleotide pyrophosphatase, which was also most highly enriched (3.2--3.3-fold) in the heavy membrane fraction, but did not follow it exactly. The enzyme was 2-fold richer in the light membranes than in the parent microsomes, though the light membrane binding activity was only 0.4--1.4 times that of the parent microsomes. High affinity binding was time and temperature dependent, saturable, and inhibited by unlabeled low density lipoproteins but not by unrelated proteins. Binding was stimulated 2--3 fold Ca2+, was not affected by treatment with Pronase or trypsin and was inhibited by low concentrations of phospholipids and high density lipoproteins (HDL). Heparin-Mn2+ treatment of HDL did not affect its ability to inhibit [125I] LDL binding. The LDL recognition site was distinct from the liver membrane asialoglycoprotein receptor; LDL binding was not inhibited by desialidated fetuin. We conclude that porcine liver contains a high affinity binding site that recognizes features common to both pig low density and high density lipoproteins. Further studies may elucidate the significance of this binding site in lipoprotein metabolism.