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242 Cardio Diabetes Medicine 2017

Intravenous Thrombolysis in patients Taking newer Even among patients who are treated with reperfu-
anticoagulants Iv rtPA can be administered within sion strategies, mortality remains high(30% to 35%)
3 hours of symptom onset to patients taking warfa- therefore many cinsider extending the therapeutic
rin whose international normalized ratio (INR) is 1.7 window for IV thrombolysis beyond 4.5 hours and
or less However, no adequate safety data with the for mechanical thrombectomy far beyond 6 hours
newer anticoagulants (The direct thrombin inhibitor in patients with basilar artery occlusion who do not
dabigatran and the factor Xa inhibitors rivaroxaban have a large established pontine or cerebellar infarc-
apixaban, and edoxaban) exist. Readily available lab- tion to be reasonable.
oratory studies cannot quantify the degree of anti-
coagulation. Thus, it is most prudent to withhold Future Directions
thrombolysis in patients taking these agents. Howev- Current efforts are focused on increasing the effi-
er patients with proximal intracranial artery occlusion ciency of systems of care and investigating new
may benefit from mechanical thrombectomy.
strategies for acute stroke therapy the common
objective is to increase the number of patients with
Minor and rapidly improving deficits acute ischemic stroke who can regain perfusion of
Although thrombolysis is often with held because the the ischemic tissue before infarction is established.
symptoms are considered mild or patients appear to Mobile stroke units are rapidly gaining acceptance.
be rapidly improving, Several observational studies These are special ambulances equipped with a por-
have shown that up to one-third of patients who are table CT scanner and digital technology to enable
otherwise eligible for thrombolysis but do not receive telecommunication with a stroke specialist they have

it for these reasons are disabled at 3 months. Thus, been shown to allow safe initiation of IV thrombol-
one must be very careful when assessing these pa- ysis while en route to the stroke centre. This option,
tients IV rtPA might be justified when the NHSS score although expensive can be very welcome solution
is low but the symptoms are nonetheless disabling for some heavily populated urban communities.
for the patient(eg, hemianopia)
Dispatchers and paramedics must receive specific
Improving deficits that are still disabling at the time stroke education to optimize the efficiency and safe-
of the neurologic evaluation may similarly warrant ty of these mobile units.
thrombolysis The value of IV rtPA within 3 hours of Ways to extend the therapeutic window (beyond
symptom onset in patients with mild (NIHSS score 4.5 hours for IV therapy and 6 hours for mechanical
of 5 or less) or rapidly improving deficits is being in- thrombectomy ) are being actively investigated us-
vestigated in the phase IIIB, Double-blind, Multicenter ing more fibrin- specific fibrinolytic agents has been
study to Evalute the Efficacy and safety of Alteplase considered a promising option for years trials using
in patients with mild stroke rapidly improving symp- desmoteplase showed no benefit, but tenecteplase
toms and Neurologic Deficits(PRISMS) trial.
is still beging studied. Radiologic identification of
patients with better collateral flow resulting in per-
Posterior circulation strokes sistently salvageable tissue is broadly considered a
Randomized trials of IV thrombolysis and mechanical reasonable albeit still unproven approach. Selection
thrombectomy (except for very few patients enrolled of candidates using perfusion imaging modalities is
in the contribution of intra- arterial thrombectomy in being tested in ongoing trials (DAWN,DEFUSE3,and
acute ischemic stroke in patients with intravenous MR WITHNESS).
thrombolysis [THRACE] trial) have been restricted to
patients with anterior circulation strokes. yet clinical Collateral flow augmentation is an other proposed
experience with treating posterior circulation infarc- strategy in current practice, this is sometimes at-
tions with these therapies exists. Basilar artery oc- tempted with vasopressors evidence is restricted to

clusions can be devastating unless recanalization small case series and one pilot feasibility study yet
it achieved registry data indicate that IV rtPA and hemodynamic augmentation with vasopressors can

mechanical thrombectomy can result in functional occasionally work, in particular in patients with prox-

independence at 3 monthsin30% to 40% of cases; imal vessel occlusions who are not deemed candi-
these rates of favorable outcome are clearly great- dates for endovascular recanalization or in whom the
er than those reported without reperfusion therapy. recanalization attempt was unsuccessful mechanical
The value of endovascular therapy for acute basilar techniques for collateral recruitment(such as exter-
occlusion is currently being investigated in the bas- nal counterpulsation and intraaortic inflation devices)
ilar artery international cooperation study (BASICS). have been shown feasible and but their efficacy re-

GCDC 2017