Validation of Repeated Endothelial Function Measurements Using EndoPAT in Stroke

BackgroundDecreased endothelial function (EF) may be a prognostic marker for stroke. Measuring pharmacological effects on EF may be of interest in the development of personalized medicine for stroke prevention. In this study, we assessed the reliability of repeated EF measurements using a pulse amplitude tonometry technology in acute stroke patients. Similarly, reliability was tested in healthy subjects devoid of vascular disease to estimate reactivity and reliability in a younger non-stroke population.Materials and methodsEF was assessed using the EndoPAT2000 in 20 healthy volunteers (men 50%, mean age 35.85 ± 3.47 years) and 21 stroke patients (men 52%, mean age 66.38 ± 2.85 years, and mean NIHSS 4.09 ± 0.53) under standardized conditions. EF was measured as the reactive hyperemia index (RHI), logarithm of RHI (lnRHI), and Framingham RHI (fRHI). Measurements were separated by 1.5 and 24 h to assess same-day and day-to-day reliability, respectively.ResultsFair to moderate correlations of measurements [intraclass correlation coefficient (ICC)same-day 0.29 and ICCday-to-day 0.52] were detected in healthy subjects. In stroke patients, we found moderate to substantial correlation of both same-day and day-to-day repeated measurements (ICCsame-day 0.40 and ICCday-to-day 0.62). fRHI compared with RHI and lnRHI showed best reliability.ConclusionRepeated measurements of fRHI in stroke patients show moderate reliability on same-day and substantial on day-to-day measurements. Likewise, in healthy subjects there was substantial reliability on day-to-day measurement, but only moderate on same-day measurements. In general, day-to-day correlation of repeated EF measurements was far better than that of same-day measurements, which ranged from poor to moderate depending on the specific outcome measure of EF. A possible carryover effect should be considered if same-day repeated testing of drug effects is applied in future studies

Low immediate scientific yield of the PhD among medical doctors

BACKGROUND: We studied the scientific yield of the medical PhD program at all Danish Universities. METHODS: We undertook a retrospective observational study. Three PhD schools in Denmark were included in order to evaluate the postdoctoral research production over more than 18 years through individual publications accessed by PubMed. RESULTS: A total of 2686 PhD-graduates (1995–2013) with a medical background were included according to registries from all PhD schools in Denmark. They had a median age of 35 years (interquartile range (IQR), 32–38) and 53 % were women at the time of graduation. Scientific activity over time was assessed independently of author-rank and inactivity was measured relative to the date of graduation. Factors associated with inactivity were identified using multivariable logistic regression. 88.6 % of the PhD theses were conducted in internal medicine vs. 11.4 % in surgery. During follow-up (median 6.9 years, IQR 3.0–11.7), PubMed data searches identified that 87 (3.4 %) of the PhD graduates had no publication after they graduated from the PhD program, 40 % had 5 or less, and 90 % had 30 or less. The median number of publications per year after PhD graduation was 1.12 (IQR 0.61–1.99) papers per year. About 2/3 of the graduates became inactive after 1 year and approximately 21 % of the graduates remained active during the whole follow-up. Female gender was associated with inactivity: adjusted odds ratio 1.59 (95 % confidence interval 1.24–2.05). CONCLUSIONS: The scientific production of Danish medic PhD-graduates was mainly produced around the time of PhD-graduation. After obtaining the PhD-degree the scientific production declines suggesting that scientific advance fails and resources are not harnessed

Ischemic Stroke Severity and Mortality in Patients With and Without Atrial Fibrillation

Background Our objective was to investigate stroke severity and subsequent rate of mortality among patients with and without atrial fibrillation (AF). Contemporary data on stroke severity and prognosis in patients with AF are lacking. Methods and Results First‐time ischemic stroke patients from the Danish Stroke Registry (January 2005–December 2016) were included in an observational study. Patients with AF were matched 1:1 by sex, age, calendar year, and CHA2DS2‐VASc score with patients without AF. Stroke severity was determined by the Scandinavian Stroke Scale (0–58 points). The rate of death was estimated by Kaplan‐Meier plots and multivariable Cox regression. Among 86 458 identified patients with stroke, 17 205 had AF. After matching, 14 662 patients with AF and 14 662 patients without AF were included (51.8% women; median age, 79.6 years [25th–75th percentile, 71.8–86.0]). More patients with AF had very severe stroke (0–14 points) than patients without AF (13.7% versus 7.9%, P<0.01). The absolute rates of 30‐day and 1‐year mortality were significantly higher for patients with AF (12.1% and 28.4%, respectively) versus patients without AF (8.7% and 21.8%, respectively). This held true in adjusted models for 30‐day mortality (hazard ratio [HR], 1.40 [95% CI, 1.30–1.51]). However, this association became nonsignificant when additionally adjusting for stroke severity (HR, 1.10 [95% CI, 1.00–1.23]). AF was associated with a higher rate of 1‐year mortality (HR, 1.39 [95% CI, 1.32–1.46]), although it was mediated by stroke severity (HR, 1.15 [95% CI, 1.09–1.23], model including stroke severity). Conclusions In a contemporary nationwide cohort of patients with ischemic stroke, patients with AF had more severe strokes and higher mortality than patients without AF. The difference in mortality was mainly driven by stroke severity