I see absolutely nothing in this research that does one damn bit of good in helping stroke survivors recover better.
JAMA Neurol. Published online February 27, 2017. doi:10.1001/jamaneurol.2016.5815
Question
Can etiologic stroke subtyping generate categories with discrete clinical, imaging, and prognostic characteristics?
Findings
A head-to-head, blind evaluation of Causative Classification
of Stroke, Trial of Org 10172 in Acute Stroke Treatment, and ASCO (A for
atherosclerosis, S for small-vessel disease, C for cardiac source, and O
for other cause) classification systems in 1816 consecutive patients
with ischemic stroke revealed that all systems generated etiologic
subtypes with different 90-day stroke recurrence, 90-day survival,
admission stroke severity, and acute infarct burden. The Causative
Classification of Stroke system redistributed 20% to 40% of the
population assigned into the undetermined category by other systems into
known subtypes and provided a greater discrimination for most of the
stroke characteristics tested as compared with the Trial of Org 10172 in
Acute Stroke Treatment and ASCO systems.
Meaning
Etiologic stroke classification identifies discrete categories with different stroke features.
Importance
The ability of present-day etiologic stroke classification
systems to generate subtypes with discrete stroke characteristics is not
known.
Objective
To test the hypothesis that etiologic stroke subtyping
identifies different disease processes that can be recognized through
their different clinical courses.
Design, Setting, and Participants
We performed a head-to-head evaluation of the ability of the
Causative Classification of Stroke (CCS), Trial of Org 10172 in Acute
Stroke Treatment (TOAST), and ASCO (A for atherosclerosis, S for
small-vessel disease, C for cardiac source, and O for other cause)
classification systems to generate etiologic subtypes with different
clinical, imaging, and prognostic characteristics in 1816 patients with
ischemic stroke. This study included 2 cohorts recruited at separate
periods; the first cohort was recruited between April 2003 and June 2006
and the second between June 2009 and December 2011. Data analysis was
performed between June 2014 and May 2016.
Main Outcomes and Measures
Separate teams of stroke-trained neurologists performed CCS,
TOAST, and ASCO classifications based on information available at the
time of hospital discharge. We assessed the association between
etiologic subtypes and stroke characteristics by computing receiver
operating characteristic curves for binary variables (90-day stroke
recurrence and 90-day mortality) and by calculating the ratio of
between-category to within-category variability from the analysis of
variance for continuous variables (admission National Institutes of
Health Stroke Scale score and acute infarct volume).
Results
Among the 1816 patients included, the median age was 70 years
(interquartile range, 58-80 years) (830 women [46%]). The classification
systems differed in their ability to assign stroke etiologies into
known subtypes; the size of the undetermined category was 33% by CCS,
53% by TOAST, and 42% by ASCO (P < .001 for all binary
comparisons). All systems provided significant discrimination for the
validation variables tested. For the primary validation variable (90-day
recurrence), the area under the receiver operating characteristic curve
was 0.71 (95% CI, 0.66-0.75) for CCS, 0.61 (95% CI, 0.56-0.67) for
TOAST, and 0.66 (95% CI, 0.60-0.71) for ASCO (P = .01 for CCS vs ASCO; P < .001 for CCS vs TOAST; P
= .13 for ASCO vs TOAST). The classification systems exhibited similar
discrimination for 90-day mortality. For admission National Institutes
of Health Stroke Scale score and acute infarct volume, CCS generated
more distinct subtypes with higher between-category to within-category
variability than TOAST and ASCO.
Conclusions and Relevance
Our findings suggest that the major etiologic stroke subtypes
are distinct categories with different stroke characteristics
irrespective of the classification system used to identify them. We
further show that CCS generates discrete etiologic categories with more
diverse clinical, imaging, and prognostic characteristics than either
TOAST or ASCO.
