Sex-related differences in functional capacity and its implications in risk stratification before major non-cardiac surgery: a post hoc analysis of the international METS study.

Background: Poor functional capacity has been identified as an important modifiable risk factor for postoperative complications. Cardiopulmonary exercise testing (CPET) provides objective parameters of functional capacity (e.g., oxygen consumption at peak exercise, peak VO2), with significant prognostication for postoperative complications. However, sex-specific thresholds for functional capacity to predict surgical risk are yet to be established. Therefore, we performed a post hoc analysis of the international, multicentre, prospective observational METS (Measurement of Exercise Tolerance before Surgery) study to evaluate if sex-specific thresholds of peak VO2 improve risk prediction of postoperative complications. Methods: We undertook a post hoc analysis (HREC/71824/PMCC) of the METS study, which was performed between March 2013 and March 2016. We investigated whether sex-specific differences exist for CPET-derived parameters and associated thresholds for predicting postoperative complications in this large cohort of patients that had major non-cardiac surgery (n = 1266). Logistic regression models were analyzed for the association of low peak VO2 with moderate-to-severe in-hospital postoperative complications. Optimal sex-specific peak VO2 thresholds were obtained by maximizing the Youden index of receiver operating characteristic (ROC) curves. Finally, multivariable logistic regression models tested the resulting sex-specific thresholds against the established non-sex-specific peak VO2 threshold (14 mL kg-1 min-1) adjusted for clinically relevant features such as comorbidities and surgical complexity. Models were evaluated by bootstrapping optimism-corrected area under the ROC curve and the net reclassification improvement index (NRI). Findings: Female patients (n = 480) had a lower mean (SD) peak VO2 than males (16.7 (4.9) mL kg-1 min-1 versus 21.2 (6.5) mL kg-1 min-1, p < 0.001) and a lower postoperative complication rate (10.4% versus 15.3%; p = 0.018) than males (n = 786). The optimal peak VO2 threshold for predicting postoperative complications was 12.4 mL kg-1 min-1 for females and 22.3 mL kg-1 min-1 for males, respectively. In the multivariable regression model, low non-sex-specific peak VO2 did not independently predict postoperative complications. In contrast, low sex-specific peak VO2 was an independent predictor of postoperative complications (OR 2.29; 95% CI: 1.60, 3.30; p < 0.001). The optimism-corrected AUC-ROC of the sex-specific model was higher compared with the non-sex-specific model (0.73 versus 0.7; DeLong's test: p = 0.021). The sex-specific model classified 39% of the patients more correctly than the baseline model (NRI = 0.39; 95% CI: 0.24, 0.55). In contrast, the non-sex-specific model only classified 9% of the patients more correctly when compared against the baseline model (NRI = 0.09; 95% CI: -0.04, 0.22). Interpretation: Our data report sex-specific differences in preoperative CPET-derived functional capacity parameters. Sex-specific peak VO2 thresholds identify patients at increased risk for postoperative complications with a higher discriminatory ability than a sex-unspecific threshold. As such, sex-specific threshold values should be considered in preoperative CPET to potentially improve risk stratification and to guide surgical decision-making, including eligibility for surgery, preoperative optimization strategies (prehabilitation) or seeking non-surgical options. Funding: There was no funding for the present study. The original METS study was funded by Canadian Institutes of Health Research, Heart and Stroke Foundation of Canada, Ontario Ministry of Health and Long-Term Care, Ontario Ministry of Research, Innovation and Science, UK National Institute of Academic Anaesthesia, UK Clinical Research Collaboration, Australian and New Zealand College of Anaesthetists, and Monash University.

Radiation necrosis and therapeutic outcomes in patients treated with linear accelerator-based hypofractionated stereotactic radiosurgery for intact intracranial metastases.

INTRODUCTION: Balancing disease control and treatment-related toxicities can be challenging when treating higher-risk brain metastases (BMs) that are larger in size or eloquent anatomical locations. Hypofractionated stereotactic radiosurgery (hfSRS) is expected to offer superior or equal efficacy with lower toxicity profile compared with single-fraction SRS (sfSRS). We report the efficacy and toxicity profiles of hfSRS in a consecutive cohort of patients to support this predicted benefit from hfSRS for high-risk BMs. METHODS: We retrospectively analysed 185 consecutive individual lesions from 152 patients with intact BMs treated with hfSRS between 1 July 2016 and 31 October 2019 and followed up to 30 April 2022 with serial brain magnetic resonance imaging (MRI). The primary endpoint was the event of radiation necrosis (RN). Local control (LC) rate and distant brain failure (DBF) were reported as secondary outcomes. Kaplan-Meier method was used to report the cumulative incidence of RN and overall survival and the incidence of DBF. Potential risk factors for RN were assessed using univariable Cox regression analysis. RESULTS: The median follow-up was 38.0 months, and the median survival post-SRS was 9.5 months. The cumulative incidence rate of RN was 13.2% (95% CI: 7.0-24.7%), and 18.1% of patients with confirmed RN were symptomatic. Higher mean dose delivered to planning target volume (PTV) (HR 1.22, 95% CI: 1.05-1.42, P = 0.01), higher mean BED10 (biological equivalent dose assuming a tissue α / ß ratio of 10) (HR 1.12, 95% CI: 1.04-1.2, P < 0.001), and higher mean BED2 (HR 1.02, 95% CI: 1-1.04, P = 0.04) delivered to the lesion was associated with increased risk of RN. LC rate was 86% and the cumulative incidence of DBF was 36% with a median onset of 28.4 months. CONCLUSIONS: Our results support the predicted radiobiological benefit of the use of hfSRS in high-risk BMs to limit treatment-related toxicity with low risk for symptomatic RN comparable with lower risk population receiving sfSRS while achieving satisfactory local disease control.

Workers in Australian prebake aluminium smelters: update on risk of mortality and cancer incidence in the Healthwise cohort.

OBJECTIVES: To investigate mortality and the rates of incident cancer among a cohort of aluminium industry workers. METHODS: Among 4507 male employees who worked in either of two Australian prebake smelters for at least 3 months, data linkage was undertaken with the Australian National Death Index and Australian Cancer Database. Standardised Mortality Ratios (SMRs) and Standardised Incidence Rates (SIRs) were estimated for the whole cohort and for: production; maintenance and office workers. SMRs and SIRs were calculated by time since first employment. RESULTS: Among production workers, there was an excess risk of mortality from mesothelioma (SMR 2.8, 95% CI 1.3 to 5.2), lung (SMR 1.4, 95% CI 1.0 to 1.8), prostate (SMR 1.9, 95% CI 1.3 to 2.7) and liver cancer (SMR 2.0, 95% CI 1.1 to 3.4) and the SIR was also increased for overall respiratory cancers, specifically lung cancers. An excess risk of death from stomach cancer (SMR 2.9, 95% CI 1.2 to 6.1) and Alzheimer's disease (SMR 3.4, 95% CI 1.1 to 7.9) was seen among maintenance workers. The overall risk of death was similar to that of the Australian general population, as was mortality from cancers overall and non-malignant respiratory disease. CONCLUSIONS: No excess risk of death from bladder cancer or non-malignant respiratory disease was found. Excess lung cancer mortality and incidence may be explained by smoking and excess mortality from mesothelioma may be explained by asbestos exposure. An excess risk of mortality from liver and prostate cancer has been shown in production workers and requires further investigation.

The PAR4 Platelet Thrombin Receptor Variant rs773902 does not Impact the Incidence of Thrombotic or Bleeding Events in a Healthy Older Population.

BACKGROUND: Protease-activated receptor 4 (PAR4) is a platelet thrombin receptor important for thrombosis and a target of antiplatelet drug development. A frequently occurring single-nucleotide polymorphism (rs773902) causes a PAR4 sequence variant (NC_000019.10:p.Ala120Thr) whereby platelets from Thr120-expressing individuals are hyperresponsive to PAR4 agonists versus platelets from Ala120-expressing individuals. However, whether this enhanced platelet responsiveness translates to increased thrombotic risk or decreased bleeding risk remains unknown. OBJECTIVES: This article examines the association of rs773902 with adjudicated cardiovascular events and aspirin use in a randomized trial population of healthy older individuals. METHODS: We analyzed 13,547 participants in the ASPirin in Reducing Events in the Elderly trial. Participants had no previous cardiovascular events at enrollment and were randomized to either 100 mg daily aspirin or placebo for a median follow-up of 4.7 years. Total genotypes were 8,761 (65%) GG (Ala120 variant), 4,303 (32%) heterozygotes, and 483 (4%) AA (Thr120 variant). Cox proportional hazard regression tested the relationship between rs773902 and thrombotic events (major adverse cardiovascular events [MACE] and ischemic stroke [IS]) and bleeding (major hemorrhage [MHEM] and intracranial bleeding [ICB]). RESULTS: No statistically significant association was observed overall or by treatment group between rs773902 and any thrombotic or bleeding event examined. Further, there was no significant interaction between rs773902 and treatment for any of MACE, IS, MHEM, or ICB. CONCLUSION: This post hoc analysis of a prospective cohort study suggests that, despite sensitizing platelet activation, the rs773902 PAR4 variant is not associated with thrombotic cardiovascular or bleeding events in a healthy older population.

Genetic Variation in PEAR1, Cardiovascular Outcomes and Effects of Aspirin in a Healthy Elderly Population.

The platelet endothelial aggregation receptor-1 (PEAR1) rs12041331 variant has been identified as a genetic determinant of platelet aggregation in response to antiplatelet therapies, including aspirin. However, association with atherothrombotic cardiovascular events is less clear, with limited evidence from large trials. Here, we tested association of rs12041331 with cardiovascular events and aspirin use in a randomized trial population of healthy older individuals. We undertook post hoc analysis of 13,547 participants of the ASPirin in Reducing Events in the Elderly (ASPREE) trial, median age 74 years. Participants had no previous diagnosis of atherothrombotic cardiovascular disease at enrollment, and were randomized to either 100 mg daily low-dose aspirin or placebo for median 4.7 years follow-up. We used Cox proportional hazard regression to model the relationship between rs12041331 and the ASPREE primary cardiovascular disease (CVD) end point, and composites of major adverse cardiovascular events (MACE) and ischemic stroke (STROKE); and bleeding events; major hemorrhage (MHEM) and intracranial bleeding (ICB). We performed whole-population analysis using additive and dominant inheritance models, then stratified by treatment group. Interaction effects between genotypes and treatment group were examined. We observed no statistically significant association (P < 0.05) in the population, or by treatment group, between rs12041331 and cardiovascular or bleeding events in either model. We also found no significant interaction effects between rs12041331-A and treatment group, for CVD (P = 0.65), MACE (P = 0.32), STROKE (P = 0.56), MHEM (P = 0.59), or ICB (P = 0.56). The genetic variant PEAR1 rs12041331 is not associated with cardiovascular events in response to low-dose aspirin in a healthy elderly population.

CT and MRI findings in leptomeningeal melanocytosis.

Leptomeningeal melanocytosis is a rare cause of seizure in the pediatric population. Shown here is a case of this disease in a 9-year-old male who presented with seizures and minor trauma. Imaging showed progression of leptomeningeal enhancement in the setting of increased seizure activity, and biopsy confirmed the diagnosis. The patient received immunotherapy but eventually succumbed to the disease. This case serves as an educational tool to improve awareness of melanocytic proliferation as a differential consideration for leptomeningeal enhancement.

MRA and ASL perfusion findings in pediatric reversible cerebral vasoconstriction syndrome.

Reversible vasoconstriction is rare in the pediatric population. Typically manifesting as peripheral vasoconstriction with variable neurologic symptoms, Reversible cerebral vasoconstriction syndrome is often a diagnosis of exclusion and may not be diagnosed in the absence of angiographic imaging. Shown here are 2 cases of pediatric Reversible cerebral vasoconstriction syndrome with disparate MRI findings and arterial spin labeling perfusion findings.

Insights into the genetic architecture of early stage age-related macular degeneration: a genome-wide association study meta-analysis.

Genetic factors explain a majority of risk variance for age-related macular degeneration (AMD). While genome-wide association studies (GWAS) for late AMD implicate genes in complement, inflammatory and lipid pathways, the genetic architecture of early AMD has been relatively under studied. We conducted a GWAS meta-analysis of early AMD, including 4,089 individuals with prevalent signs of early AMD (soft drusen and/or retinal pigment epithelial changes) and 20,453 individuals without these signs. For various published late AMD risk loci, we also compared effect sizes between early and late AMD using an additional 484 individuals with prevalent late AMD. GWAS meta-analysis confirmed previously reported association of variants at the complement factor H (CFH) (peak P = 1.5×10(-31)) and age-related maculopathy susceptibility 2 (ARMS2) (P = 4.3×10(-24)) loci, and suggested Apolipoprotein E (ApoE) polymorphisms (rs2075650; P = 1.1×10(-6)) associated with early AMD. Other possible loci that did not reach GWAS significance included variants in the zinc finger protein gene GLI3 (rs2049622; P = 8.9×10(-6)) and upstream of GLI2 (rs6721654; P = 6.5×10(-6)), encoding retinal Sonic hedgehog signalling regulators, and in the tyrosinase (TYR) gene (rs621313; P = 3.5×10(-6)), involved in melanin biosynthesis. For a range of published, late AMD risk loci, estimated effect sizes were significantly lower for early than late AMD. This study confirms the involvement of multiple established AMD risk variants in early AMD, but suggests weaker genetic effects on the risk of early AMD relative to late AMD. Several biological processes were suggested to be potentially specific for early AMD, including pathways regulating RPE cell melanin content and signalling pathways potentially involved in retinal regeneration, generating hypotheses for further investigation.