Systemic embolism in amyloid transthyretin cardiomyopathy

AIMS

Although systemic embolism is a potential complication in transthyretin amyloid cardiomyopathy (ATTR-CM), data about its incidence and prevalence are scarce. We studied the incidence, prevalence and factors associated with embolic events in ATTR-CM. Additionally, we evaluated embolic events according to the type of oral anticoagulation (OAC) and the performance of the CHA2 DS2 -VASc score in this setting.

METHODS AND RESULTS

Clinical characteristics, history of atrial fibrillation (AF) and embolic events were retrospectively collected from ATTR-CM patients evaluated at four international amyloid centres. Overall, 1191 ATTR-CM patients (87% men, median age 77.1 years [interquartile range-IQR 71.4-82], 83% ATTRwt) were studied. A total of 162 (13.6%) have had an embolic event before initial evaluation. Over a median follow-up of 19.9 months (IQR 9.9-35.5), 41 additional patients (3.44%) had an embolic event. Incidence rate (per 100 patient-years) was 0 among patients in sinus rhythm with OAC, 1.3 in sinus rhythm without OAC, 1.7 in AF with OAC, and 4.8 in AF without OAC. CHA2 DS2 -VASc did not predict embolic events in patients in sinus rhythm whereas in patients with AF without OAC, only those with a score ≥4 had embolic events. There was no difference in the incidence rate of embolism between patients with AF treated with vitamin K antagonists (VKAs) (n = 322) and those treated with direct oral anticoagulants (DOACs) (n = 239) (p = 0.66).

CONCLUSIONS

Embolic events were a frequent complication in ATTR-CM. OAC reduced the risk of systemic embolism. Embolic rates did not differ with VKAs and DOACs. The CHA2 DS2 -VASc score did not correlate well with clinical outcome in ATTR-CM and should not be used to assess thromboembolic risk in this population.

Diverse clinical and social circumstances: developing patient-centred care for DR-TB patients in South Africa

OBJECTIVE

To describe the medical, socio-economic and geographical profiles of patients with rifampicin-resistant TB (RR-TB) and the implications for the provision of patient-centred care.

SETTING

Thirteen districts across three South African provinces.

DESIGN

This descriptive study examined laboratory and healthcare facility records of 194 patients diagnosed with RR-TB in the third quarter of 2016.

RESULTS

The median age was 35 years; 120/194 (62%) of patients were male. Previous TB treatment was documented in 122/194 (63%) patients and 56/194 (29%) had a record of fluoroquinolone and/or second-line injectable resistance. Of 134 (69%) HIV-positive patients, viral loads were available for 68/134 (51%) (36/68 [53%] had viral loads of >1000 copies/ml) and CD4 counts were available for 92/134 (69%) (20/92 [22%] had CD4 <50 cells/mm3). Patients presented with varying other comorbidities, including hypertension (13/194, 7%) and mental health conditions (11/194, 6%). Of 194 patients, 44 (23%) were reported to be employed. Other socio-economic challenges included substance abuse (17/194, 9%) and ill family members (17/194, 9%). Respectively 13% and 42% of patients were estimated to travel more than 20 km to reach their diagnosing and treatment-initiating healthcare facility.

CONCLUSIONS

RR-TB patients had diverse medical and social challenges highlighting the need for integrated, differentiated and patient-centred healthcare to better address specific needs and underlying vulnerabilities of individual patients.

Drug-resistant tuberculosis patient care journeys in South Africa: a pilot study using routine laboratory data

SETTING: Thirteen districts in Eastern Cape (EC), KwaZulu-Natal (KZN) and Western Cape (WC) Provinces, South Africa.OBJECTIVE: To pilot a methodology for describing and visualising healthcare journeys among drug-resistant tuberculosis (DR-TB) patients using routine laboratory records.DESIGN: Laboratory records were obtained for 195 patients with laboratory-detected rifampicin-resistant TB (RR-TB) during July-September 2016. Health facility visits identified from these data were plotted to visualise patient healthcare journeys. Data were verified by facility visits.RESULTS: In the 9 months after the index RR-TB sample was collected, patients visited a mean of 2.3 health facilities (95% CI 2.1-2.6), with 9% visiting ≥4 facilities. The median distance travelled by patients from rural areas (116 km, interquartile range [IQR] 50-290) was greater than for urban patients (51 km, IQR 9-140). A median of 21% of patient's time was spent under the care of primary healthcare facilities: this was respectively 6%, 37% and 39% in KZN, EC and WC. Journey patterns were generally similar within districts. Some reflected a semi-centralised model of care where patients were referred to regional hospitals; other journeys showed greater involvement of primary care.CONCLUSION: Routine laboratory data can be used to explore DR-TB patient healthcare journeys and show how the use of healthcare services for DR-TB varies in different settings.

Strategy of Using Intratreatment Hypoxia Imaging to Selectively and Safely Guide Radiation Dose De-escalation Concurrent With Chemotherapy for Locoregionally Advanced Human Papillomavirus-Related Oropharyngeal Carcinoma

PURPOSE

To report a small substudy of an ongoing large, multi-arm study using functional imaging to assess pre-/intratreatment hypoxia for all head and neck cancer, in which we hypothesized that pre- and early-treatment hypoxia assessment using functional positron emission tomography (PET) imaging may help select which human papillomavirus (HPV)-positive (HPV(+)) oropharyngeal cancer (OPC) patients can safely receive radiation de-escalation without jeopardizing treatment outcomes.

METHODS AND MATERIALS

Patients with HPV(+) oropharyngeal carcinoma were enrolled on an institutional review board-approved prospective study of which de-escalation based on imaging response was done for node(s) only. Pretreatment (18)F-fluorodeoxyglucose and dynamic (18)F-FMISO (fluoromisonidazole) positron emission tomography (PET) scans were performed. For patients with pretreatment hypoxia on(18)F-FMISO PET (defined as a >1.2 tumor to muscle standard uptake value ratio), a repeat scan was done 1 week after chemoradiation. Patients without pretreatment hypoxia or with resolution of hypoxia on repeat scan received a 10-Gy dose reduction to metastatic lymph node(s). The 2-year local, regional, distant metastasis-free, and overall survival rates were estimated using the Kaplan-Meier product-limit method. A subset of patients had biopsy of a hypoxic node done under image guidance.

RESULTS

Thirty-three HPV(+) OPC patients were enrolled in this pilot study. One hundred percent showed pretreatment hypoxia (at primary site and/or node[s]), and among these, 48% resolved (at primary site and/or node[s]); 30% met criteria and received 10-Gy reduction to the lymph node(s). At the median follow-up of 32 months (range, 21-61 months), the 2-year locoregional control rate was 100%. One patient failed distantly with persistence of hypoxia on (18)F-FMISO PET. The 2-year distant metastasis-free rate was 97%. The 2-year OS rate was 100%. Hypoxia on imaging was confirmed pathologically.

CONCLUSIONS

Hypoxia is present in HPV(+) tumors but resolves within 1 week of treatment in 48% of cases either at the primary site and/or lymph node(s). Our 100% locoregional control rate suggests that intratreatment functional imaging used to selectively de-escalate node(s) to 60 Gy was confirmed safe using our stringent imaging criteria. Intratreatment functional imaging warrants further study to determine its ultimate role in de-escalation treatment strategies.

Survey of patient and physician influences and decision-making regarding CT utilization for minor head injury

OBJECTIVE

Assess factors that influence both the patient and the physician in the setting of minor head injury in adults and the decision-making process around CT utilization.

METHODS

This is a convenience sample survey study of adult minor head injury patients (GCS 15) and their physicians regarding factors influencing the decision to use CT to evaluate for intra-cranial haemorrhage. Once a head CT was ordered and before the results were known, both the patient and physician were given a one-page survey asking questions about their concern for injury and rationale for CT use. CT results and surveys were then recorded in a centralized database and analyzed.

RESULTS

584 subjects were enrolled over the 27-month study period. The rate of any intra-cranial haemorrhage was 3.3%. Both the physicians (6% pre-test estimate) and the patients (22% pre-test estimate) over-estimated risk for haemorrhage. Clinical decision rules were not met in 46% of cases where CT was used. Physicians listed an average of 5 factors from a list of 9 that influenced their decision to order CT. Patients listed an average of 1.7 factors influencing their decision to present to the Emergency Department for evaluation. Many patients felt cost (45%) and low risk stratification (34%) should weigh heavily in the decision to use CT. If asked to limit CT utilization, physicians were able to identify a group with less than 2% risk of injury.

CONCLUSIONS

Patients with low risk of intra-cranial injury continue to be evaluated by CT. Physician decision-making around the use of CT to evaluate minor head injury is multi-factorial. Shared decision-making between the patient and the physician in a low risk minor head injury encounter shows promise as a method to reduce CT utilization in this low risk cohort.

[Prevalence of human immunodeficiency virus infection and behaviors associated with its transmission among parenteral drug users selected on the street]

BACKGROUND

To estimate the prevalence of HIV infection and the associated risk behaviours among intravenous drug users not receiving treatment for their drug dependence.

PATIENTS AND METHODS

A cross-sectional study of 200 intravenous drug users recruited from the streets of Barcelona in 1993. Information about the socio-demographic aspects and behaviours was obtained through a personal interview using a standardised questionnaire which was carried out by three ex-drug users. Saliva samples were used to determine anti HIV antibodies.

RESULTS

The prevalence of HIV infection was 51%. 57% borrowed used syringes, 65% lended their syringes, and 41% practised back of frontloading. 85% if those who shared syringes always cleaned them, however 59% only used water. 78% had heterosexual relations, in 33% of the cases with a non-injecting sexual partner. 65% always used condoms with sexual clients although only 26% always used them with stable sexual partners and 36% with casual sexual partners. 78% had performed the HIV test and among those who knew they were seropositive, 40% had received some kind of health control in the last 6 months. Not having a legal income, injecting speedball or barbiturates, unknowing self HIV negative status and practicing forms of indirect sharing were found to be independently associated with syringe sharing.

CONCLUSIONS

The high prevalence of HIV infection and associated risk behaviours highlights the need to increase and adapt the prevention efforts and investigation to this group. Social marginalization and poliuse of drugs should be addressed in HIV prevention programs.

Perceiving the center of irregular contour quadrangles

This investigation examined how subjects perceived and localized the centers of irregular quadrangles. Five contour figures in four orientations were used. Seventeen subjects localized the centers of the figures in each orientation, three times. The estimated positions were found to be distributed according to the two-dimensional normal law. The mean position of the perceived center was very close to the centroid of the figures if they were considered flat homogeneous bodies. The orientation of the figures influenced the distributions of the estimates. The axis of maximal variance of the estimates was very close to the axis of orientation of the figures.

Errors in estimating the orientation of dot patterns

The error in estimating the orientation of a dot pattern was measured as the difference between the orientation of the least-squared-distances line (LS-line) of the pattern and the orientation of a line adjusted by the subject to match the perceived orientation of the pattern. Analysis of the mean errors (averaged over ten subjects) obtained for one hundred patterns confirmed that the orientation of the LS-line represents the orientation of elongated dot-patterns. It is shown that estimated orientation was systematically biased towards the nearest 45 degrees oblique meridian. This bias points to the importance of the +/-45 degrees directions as natural norms for left- and right-side tilt in the frontoparallel plane.

Half-field asymmetry in visual perception of distance

Distances were presented to the right and left halves of the visual field during steady fixation of a central point. Two methods of evaluation were used: direct scaling and the method of limits. A small but statistically significant difference was found between the estimates of distances presented to the left and to the right of the fixation point by direct scaling. No difference was found when the method of limits was used. The results are interpreted as evidence for the existence of functional asymmetry connected with the computation-and-speech ability of the hemispheres. No evidence for perception asymmetry could be found.

Retinal location and visual localization during pursuit eye movement

Experiments were performed to measure the mislocation of a brief visual stimulus presented during pursuit eye movements in different places over the retina. The results obtained show that the mislocation for regions 5 degrees from fovea in the direction of motion is greater than in fovea. This fact shows that some kind of reorganization takes place in the visual localization mechanisms during pursuit eye movements. The results cast doubts on the concept of "perception time" which is often used to explain the visual mislocation phenomenon.

Scanning open and closed polygons

The process of selection of target points during voluntary eye movements when contoured polygonal shapes with open and closed angles are observed was analysed in humans by means of an eye recording technique. It has been found for both types of stimuli that the majority of fixation points where located at angles and that the mean value of distribution was found to be more distant from the vertex for acute angles than for obtuse ones. In this respect a difference was found between open and closed contours. In the former case the mean values of fixation point distribution were more distant from the vertex and the dispersion of eye fixation was greater.

Visual localization during eye tracking on steady background and during steady fixation on moving background

Experiments were performed to clarify the role of the background motion on the retina in the phenomenon of mislocation of brief visual stimuli during smooth eye tracking. It was found that these visual stimuli were mislocated also relative to a moving background during steady eye fixation. The magnitude of mislocation during pursuit eye movements and during steady fixation was influenced by the stimulus intensity, the background/eye velocity and the place of stimulus presentation in respect to the background; the influence having the same features in both cases. However, the magnitudes of mislocation under the two conditions were quantitatively different. The validity of a hypothesis that the eye movement itself plays no role in the process of localization, and, that this process is based on retinal information only, is considered.

Some temporal characteristics of eye tracking

The frequency of occurence and the latency of eye tracking determined by moving stimuli of different velocities (5, 10 and 15 degrees/s) and different durations (between 50 and 400 ms) were measured. The result was that eye movement can occur only if the duration of the stimulus exceeds a critical value. This value depends on the stimulus velocity. The difference between the latency of the movement and the critical duration of the stimulus however remains constant. This difference is interpreted as the time necessary for selecting and releasing the appropriate programme for eye movement.

Various background pattern-effect on saccadic suppression

It has been proved that the saccadic suppression is a phenomenon closely related to the presence of contours and structures in the visual field. Experiments were performed to clarify whether the structured background influences the pattern of attention distribution (making the stimulus detection more difficult) or whether the elevation of visual threshold is due to the "masking' effect of the moving background image over the retina. Two types of backgrounds were used therefore: those with symbolic meaning in the processing of which "psychological' mechanisms are presumably involved like picture reproductions of famous painters and photographs of nudes, and those lacking semantic significance like computer figures composed of randomly distributed black and white squares with different grain expressed as the entropy of the pattern. The results show that saccadic suppression is primarily a consequence of peripheral mechanisms, probably of lateral inhibition in the visual field occurring in the presence of moving edges over the retina. Psychological factors have to be excluded as being fundamental for saccadic suppression.