Short-term risk prediction after major lower limb amputation: PERCEIVE study

BACKGROUND

The accuracy with which healthcare professionals (HCPs) and risk prediction tools predict outcomes after major lower limb amputation (MLLA) is uncertain. The aim of this study was to evaluate the accuracy of predicting short-term (30 days after MLLA) mortality, morbidity, and revisional surgery.

METHODS

The PERCEIVE (PrEdiction of Risk and Communication of outcomE following major lower limb amputation: a collaboratIVE) study was launched on 1 October 2020. It was an international multicentre study, including adults undergoing MLLA for complications of peripheral arterial disease and/or diabetes. Preoperative predictions of 30-day mortality, morbidity, and MLLA revision by surgeons and anaesthetists were recorded. Probabilities from relevant risk prediction tools were calculated. Evaluation of accuracy included measures of discrimination, calibration, and overall performance.

RESULTS

Some 537 patients were included. HCPs had acceptable discrimination in predicting mortality (931 predictions; C-statistic 0.758) and MLLA revision (565 predictions; C-statistic 0.756), but were poor at predicting morbidity (980 predictions; C-statistic 0.616). They overpredicted the risk of all outcomes. All except three risk prediction tools had worse discrimination than HCPs for predicting mortality (C-statistics 0.789, 0.774, and 0.773); two of these significantly overestimated the risk compared with HCPs. SORT version 2 (the only tool incorporating HCP predictions) demonstrated better calibration and overall performance (Brier score 0.082) than HCPs. Tools predicting morbidity and MLLA revision had poor discrimination (C-statistics 0.520 and 0.679).

CONCLUSION

Clinicians predicted mortality and MLLA revision well, but predicted morbidity poorly. They overestimated the risk of mortality, morbidity, and MLLA revision. Most short-term risk prediction tools had poorer discrimination or calibration than HCPs. The best method of predicting mortality was a statistical tool that incorporated HCP estimation.

Possible Therapeutic Effects of Adjuvant Quercetin Supplementation Against Early-Stage COVID-19 Infection: A Prospective, Randomized, Controlled, and Open-Label Study

Background

Quercetin, a well-known naturally occurring polyphenol, has recently been shown by molecular docking, in vitro and in vivo studies to be a possible anti-COVID-19 candidate. Quercetin has strong antioxidant, anti-inflammatory, immunomodulatory, and antiviral properties, and it is characterized by a very high safety profile, exerted in animals and in humans. Like most other polyphenols, quercetin shows a very low rate of oral absorption and its clinical use is considered by most of modest utility. Quercetin in a delivery-food grade system with sunflower phospholipids (Quercetin Phytosome^®, QP) increases its oral absorption up to 20-fold.

Methods

In the present prospective, randomized, controlled, and open-label study, a daily dose of 1000 mg of QP was investigated for 30 days in 152 COVID-19 outpatients to disclose its adjuvant effect in treating the early symptoms and in preventing the severe outcomes of the disease.

Results

The results revealed a reduction in frequency and length of hospitalization, in need of non-invasive oxygen therapy, in progression to intensive care units and in number of deaths. The results also confirmed the very high safety profile of quercetin and suggested possible anti-fatigue and pro-appetite properties.

Conclusion

QP is a safe agent and in combination with standard care, when used in early stage of viral infection, could aid in improving the early symptoms and help in preventing the severity of COVID-19 disease. It is suggested that a double-blind, placebo-controlled study should be urgently carried out to confirm the results of our study.

Impaired Cerebrovascular Reactivity Predicts Recurrent Symptoms in Patients with Carotid Artery Occlusion: A Hypercapnia BOLD fMRI Study

BACKGROUND AND PURPOSE

A key factor in predicting recurrent ischemic episodes in patients with carotid artery occlusion is the presence of hemodynamic impairment. There is, however, no consensus on how to best assess this risk in terms of imaging modalities or thresholds used. Here we investigated whether a predefined threshold of hemispheric asymmetry in hypercapnia fMRI predicts recurrent symptoms in patients with carotid artery occlusion.

MATERIALS AND METHODS

We studied 23 patients (2 women) with a mean age of 67.5 ± 9 years. Patients were assessed for recurrent ischemic events until lost to follow-up, study end, death, or recurrent ischemic event. Hypercapnia fMRI was used to assess the cerebrovascular reserve and quantify the percentage signal change in GM in the MCA territory and the hemispheric asymmetry index. Kaplan-Meier survival analysis and log-rank tests were performed to assess differences between patients with normal or abnormal hemispheric indices.

RESULTS

The median follow-up was 20 months. During this period, 8 patients experienced recurrent events, and 15 did not. The percentage signal change in GM in the MCA territory was significantly decreased in those patients with recurrent events compared with those without (2.39 ± 0.22 versus 2.70 ± 0.42, P = .032). The normal hemispheric index predicted event-free survival during follow-up (median, 20 months) for both the combined outcome (recurrent events and/or death, log-rank, P = .034) and recurrent retinal or ipsilateral ischemic events only (log-rank, P = .012).

CONCLUSIONS

The hemispheric asymmetry index derived from hypercapnia fMRI showed hemodynamic impairment in more than half of the studied patients with carotid occlusion, and those patients showed a higher risk of recurrent ischemic symptoms.

MR imaging-detected carotid plaque hemorrhage is stable for 2 years and a marker for stenosis progression

BACKGROUND AND PURPOSE

MR imaging-detected carotid plaque hemorrhage is associated with an increased risk of recurrent ischemic cerebrovascular events and could be an indicator of disease progression; however, there are limited data regarding the dynamics of the MR imaging-detected carotid plaque hemorrhage signal. We assessed the temporal change of this signal and its impact on carotid disease progression.

MATERIALS AND METHODS

Thirty-seven symptomatic patients with 54 carotid stenoses of >30% on sonography underwent serial MR imaging during 24 months. A signal-intensity ratio of >1.5 between the carotid plaque and adjacent muscle was defined as plaque hemorrhage, and a change in signal-intensity ratio of >0.31 between time points was considered significant. Sixteen patients underwent ≥2 carotid sonography scans to determine the peak systolic velocities and degree of stenosis with time.

RESULTS

Of the 54 carotids, 28 had the presence of hyperintense signal on an MR imaging sequence (PH+) and 26 had the absence of hyperintense signal on an MR imaging sequence (PH-) at baseline. The signal-intensity ratio was stable in 33/54 carotid plaques, but 39% showed a change. Plaque hemorrhage classification did not change in 87% of carotid plaques, but 4 became PH+, and 3, PH-. As a group, PH+ carotids did not change significantly in signal-intensity ratio (P = .585), whereas PH- showed an increased signal-intensity ratio at 24.5 months (P = .02). In PH+ plaques, peak systolic velocities significantly increased by 22 ± 39.8 cm/s from baseline to last follow-up sonography (Z = 2.427, P = .013).

CONCLUSIONS

During 2 years, MR imaging-detected carotid plaque hemorrhage status remained stable in most (87%) cases with 4 (7%) incident plaque hemorrhages. PH+ plaques were associated with increased flow velocity during the follow-up period.

Catheter-directed thrombolysis for iliofemoral deep vein thrombosis

BACKGROUND

Recent international guidance recommends the use of catheter-directed thrombolysis (CDT) in selected patients with symptomatic iliofemoral deep vein thrombosis (DVT). The aim of this study was to estimate the potential increase in workload as a result of this recommendation.

METHODS

Using the radiology database, a review was performed of all DVTs diagnosed between August 2010 and February 2012 at a large tertiary referral hospital. The National Institute for Health and Clinical Excellence and American College of Chest Physicians guidance was applied retrospectively to this cohort, using case-note review by two independent clinicians to determine which patients would have been suitable for CDT.

RESULTS

Some 563 patients had DVT confirmed radiologically over the 18-month interval. Fifty-three of the 128 patients with iliofemoral DVT would have been eligible for intervention with CDT, equivalent to 4·4 patients per 100 000 per year. Only eight (15 per cent) of the 53 were actually referred to vascular services for treatment. All eight patients had successful CDT, which involved a stay in critical care for monitoring (median 2 (range 1-3) sessions).

CONCLUSION

Vascular units should be prepared for a major increase in the requirement for CDT for iliofemoral DVT. This increase will affect inpatient beds, the interventional radiology suite, critical care and interhospital referrals.

Cerebral white matter hyperintense lesions are associated with unstable carotid plaques

OBJECTIVES

The aim of this study was to determine whether unstable carotid plaques, a known risk factor for cerebral emboli, are associated with cerebral white matter lesions.

METHODS

Seventy-one symptomatic patients undergoing magnetic resonance imaging prior to carotid endarterectomy for high grade carotid stenosis were included in this study. The number and volume of white matter hyperintense lesions (WMHL) on fluid attenuated inversion recovery brain scans were compared according to the morphology of carotid plaque based upon the American Heart Association (AHA) histological classification.

RESULTS

Of the 57 patients who had good quality brain scans and non-fragmented carotid plaques, 15 plaques were defined as stable (type V) and 42 as unstable (type VI). After adjustment for the major risk factors affecting WMHL, unstable carotid plaques were found to be associated with more WMHL in the ipsilateral cerebral hemisphere than stable plaques (transformed means 2.50+/-1.2 vs. 1.53+/-1.1, p=0.016), however, there was only a trend towards larger WMHL volumes (p=0.079).

CONCLUSIONS

The observed association between unstable carotid plaques and the number of white matter lesions suggest that thromboembolic plaque activity may contribute to the development of leukoaraiosis, in particular smaller individual lesions. Larger studies are warranted to confirm this finding and explore the potential clinical impact for selecting candidates for carotid endarterectomy.

The effect of hyperoxia on cerebral blood flow: a study in healthy volunteers using magnetic resonance phase-contrast angiography

A small decrease in cerebral blood flow (approximately 10%) in response to 100% oxygen (O2) administration is well recognized. This observation was based on human volunteer studies, which employed a nitrous oxide washout method for the measurement of cerebral blood flow. Because this method is now appreciated to be subject to potential errors we have examined the cerebral blood flow response to 100% oxygen using a magnetic resonance imaging technique to quantify changes in carotid and basilar artery flow. The study, was performed in 12 normal male subjects aged 23-42 years. We report decreases in cerebral blood flow ranging from 9 to 31% with a mean value of over 20%. The decrease in cerebral blood flow was greater in seven young subjects (aged 23-26 years) with decreases in cerebral blood flow of 19.3-31.4% (mean 26.8%). In five older subjects (aged 32-42 years), decreases in CBF were smaller (mean 16. 2%). The administration of 100% O2 was accompanied by a small decrease in end-tidal CO2 (3.7-7.1%), insufficient to explain the changes in cerebral blood flow. We conclude that the decrease in cerebral blood flow in response to O2 administration is greater than previously described and appears to be greater in young adults.