Definition and primary outcomes
Clinical and morphologic features, categorization, and grading of
comorbidities as well as outcomes measures were classified accordingly
to the reporting standards for carotid interventions appointed by the
SVS.16 Carotid stenosis was considered symptomatic if
TIA or stroke involving the ipsilateral carotid territory occurred
within 6-months of the initial assessment. Carotid cross-clamp
intolerance and necessity of shunt insertion was defined as a reduction
of >75% in baseline wave values of when using
somatosensory-evoked potentials, or >50% reduction of the
peak systolic value at the ipsilateral middle cerebral artery at
transcranial-Doppler. Severity of the complication and neurologic events
were classified accordingly to the SVS
guidelines.11,16 Neurologic complications were
classified as follow: minor stroke was a new neurologic event that
persisted for > 24 hours but completely resolved or returns
to baseline within 30 days and changed the National Institutes of Health
Stroke Scale (NIHSS) by 2 to 3 points. A major stroke was a new
neurologic event that persisted after 3 days and changed the NIHSS by at
least 4 points. Specifically for this study, primary outcome was
in-hospital mortality. Secondary outcomes were neurologic events rate,
and a composite endpoint of stroke/death rate.
Statistical analysis 17
Clinical data were recorded and tabulated in Microsoft Excel (Microsoft
Corp – Redmond; Wash – USA) database. Statistical analysis was
performed by means of SPSS 26.0 for Windows (IBM SPSS – Chicago; Ill –
USA). Categorical variables were presented using frequencies and
percentages. Continuous variables were presented with mean ± standard
deviation (SD), or median with interquartile range (IQR) and ranges,
based on data distribution. Categorical variables were analyzed with the
χ2 test, and Fisher’s exact test when appropriate.
Continuous variables were tested for normal distribution by the
Shapiro-Wilk’s test and compared between groups with unpaired Student’sT -test for normally distributed values; otherwise, the
Mann-Whitney U test was used. Tukey’s honest significance test
was used as single-step multiple comparisons to find significant
difference among means. Univariate analysis was used to identify
potential predictors of in-hospital mortality. Associations that yielded
a p value <0.20 on univariate screen were then included
in a binary logistic regression analysis using the Wald’s forward
stepwise model. The strength of the association of variables with
mortality was estimated by calculating the odd ratio (OR) and 95%
confidence intervals [(95%CI): significance criteria 0.20 for entry,
0.05 for removal)]. All reported p values were two-sided;p value <0.05 was considered significant.