Frail patients having vascular surgery during the early COVID-19 pandemic experienced high rates of adverse perioperative events and amputation.

BACKGROUND: Frailty predicts adverse perioperative outcomes and increased mortality in patients having vascular surgery. Frailty assessment is a potential tool to inform resource allocation, and shared decision-making about vascular surgery in the resource constrained COVID-19 pandemic environment. This cohort study describes the prevalence of frailty in patients having vascular surgery and the association between frailty, mortality and perioperative outcomes. METHODS: The COVID-19 Vascular Service in Australia (COVER-AU) prospective cohort study evaluates 30-day and six-month outcomes for consecutive patients having vascular surgery in 11 Australian vascular units, March-July 2020. The primary outcome was mortality, with secondary outcomes procedure-related outcomes and hospital utilization. Frailty was assessed using the nine-point visual Clinical Frailty Score, scores of 5 or more considered frail. RESULTS: Of the 917 patients enrolled, 203 were frail (22.1%). The 30 day and 6 month mortality was 2.0% (n = 20) and 5.9% (n = 35) respectively with no significant difference between frail and non-frail patients (OR 1.68, 95%CI 0.79-3.54). However, frail patients stayed longer in hospital, had more perioperative complications, and were more likely to be readmitted or have a reoperation when compared to non-frail patients. At 6 months, frail patients had twice the odds of major amputation compared to non-frail patients, after adjustment (OR 2.01; 95% CI 1.17-3.78), driven by a high rate of amputation during the period of reduced surgical activity. CONCLUSION: Our findings highlight that older, frail patients, experience potentially preventable adverse outcomes and there is a need for targeted interventions to optimize care, especially in times of healthcare stress.

Determinants of population genetic structure in eastern Chipmunks (Tamias striatus): the role of landscape barriers and sex-biased dispersal.

Dispersal and gene flow are important processes affecting the evolutionary potential of wild populations. Assessing the importance of such patterns is thus critical, especially in contexts where environmental attributes may enhance or restrict the movements of individuals across patchy habitats. A landscape genetics approach is effective in that respect as it combines spatial and genetic data to identify landscape features that play a role in shaping genetic structure. The primary objective of our research was to characterize the determinants of population genetic structure in the eastern chipmunk (Tamias striatus) over a large heterogeneous study area in southern Quebec and Ontario, Canada. We genotyped 572 individuals using 7 microsatellites loci and found an average F(ST) of 0.127 +/- 0.035 among our 7 sampling sites. We found evidence that major rivers act as important barriers to gene flow at a large scale. We also detected a signal of male-biased gene flow at all scales considered. Our findings highlight the importance of simultaneously taking into account landscape elements and geographic distance, considering the scale at which determinants of genetic structure may act and using the appropriate measures to detect sex-biased dispersal based on the characteristics of the sampling design.