In reviewing the new ASA guidelines regarding acute stroke treatment they basically say you should give IV rtPA to all eligible patients. They recommend IA thrombolysis only for patients with a significant MCA occlusion with a last time normal < 6 hours who are otherwise not candidates for IV rtPA. It appears that no IR procedures are recommended for posterior circulation strokes at this time. I have copy and pasted the specific recommendations below. For all other interventional approaches they recommend further evaluation within the context of clinical trials. Note the new language regarding the qualifications of interventionalists that has been added.
Class I Recommendations
Intra-arterial thrombolysis is an option for treatment of selected patients who have major stroke of <6 hours’ duration due to occlusions of the MCA and who are not otherwise candidates for intravenous rtPA (Class I, Level of Evidence B). This recommendation has not changed since previous guidelines.
Treatment requires the patient to be at an experienced stroke center with immediate access to cerebral angiography and qualified interventionalists. Facilities are encouraged to define criteria to credential individuals who can perform intra-arterial thrombolysis (Class I, Level of Evidence C). This recommendation has been added since previous guidelines.
Class II Recommendation
Intra-arterial thrombolysis is reasonable in patients who have contraindications to use of intravenous thrombolysis, such as recent surgery (Class IIa, Level of Evidence C). This recommendation was not included in the previous guideline.
Class III Recommendation
The availability of intra-arterial thrombolysis should generally not preclude the intravenous administration of rtPA in otherwise eligible patients (Class III, Level of Evidence C). This recommendation has not changed from previous guidelines.
Also, here are the new recommendations regarding imaging in acute stroke:
Class I Recommendations
Imaging of the brain is recommended before initiating any specific therapy to treat acute ischemic stroke (Class I, Level of Evidence A). This recommendation has not changed from the previous guideline.
In most instances, CT will provide the information to make decisions about emergency management (Class I, Level of Evidence A). This recommendation has not changed from the previous guideline.
The brain imaging study should be interpreted by a physician with expertise in reading CT or MRI studies of the brain (Class I, Level of Evidence C). This recommendation has been added since the previous guideline.
Some findings on CT, including the presence of a dense artery sign, are associated with poor outcomes after stroke (Class I, Level of Evidence A). This recommendation has not changed from the previous guideline.
Multimodal CT and MRI may provide additional information that will improve diagnosis of ischemic stroke (Class I, Level of Evidence A). This recommendation has been added since the previous guideline.
Class II Recommendations
Nevertheless, data are insufficient to state that, with the exception of hemorrhage, any specific CT finding (including evidence of ischemia affecting more than one third of a cerebral hemisphere) should preclude treatment with rtPA within 3 hours of onset of stroke (Class IIb, Level of Evidence A). This recommendation has not changed from the previous guideline.
Vascular imaging is necessary as a preliminary step for intra-arterial administration of pharmacological agents, surgical procedures, or endovascular interventions (Class IIa, Level of Evidence B). This recommendation has not changed from the previous guideline.
Class III Recommendations
Emergency treatment of stroke should not be delayed in order to obtain multimodal imaging studies (Class III, Level of Evidence C). This recommendation has been added since the previous guideline.
Vascular imaging should not delay treatment of patients whose symptoms started <3 hours ago and who have acute ischemic stroke (Class III, Level of Evidence B). This recommendation has been added since the previous guideline.
Tuesday, April 24, 2007
Sunday, April 22, 2007
Timing of TIA's preceding stroke, and ABCD score,
Time window for prevention is very short. Neurology 2005; 64:817-820. Study involved 2416 European subjects in trials or a database. 23 % of patients overall gave a history of prior TIA. 17 % occurred on the day of the stroke, 9 % on previous day,and 43 % during the previous week. A risk of 1-2 % at seven days and 2-4 % at one month is usually quoted but omits fact that patients were not recruited until 2 weeks were up. The true early risk may be much higher, even tenfold higher.
Risk of stroke after TIA (cf slide by Brott) average of about 12 studies was about 5 % in first 2 days, 12 % in first 90 days. Kaiser and California studies were cited specifically. 1702 patients presented to California ED's received a diagnosis of TIA and were followed for three months, from record review. ABCD score was derived age > 60 (1 point), bp > 140/90 (1 point), clinical (unilateral weakness 2 points, speech disturbance without weakness one point) and duration (> 60 min, 2 points; 15 m to 60 m, 1 point) Final score 0-6 (Lancet 2005 Rothwell). OR California ABCD score (age> 60 one point, DM 1 pt, duration > 10 min 1 point,any weakness 1 pt, any speech impairment 1 pt, 0-5 score, Johnston JAMA 2000). ABCD (2) score Lancet 2007: age 1 pt, bp 1 pt, weakness/speech impairment 2/1 pts, dur >60 2 pt, 15-60 1 pt, dm 1 pt, 0-7 scale).
ABCD(2) score was validated and is ready for clinical use. 2 day risks for score (0-3) 1 %; score 4-5 (4%), score 6-7 (8%). Pct of patients in low medium and high risk groups were respectively34, 45, 21 respectively.
From Lancet article(2007) 90 day risk appears 0-3 (4 %?), score 4-5 9-13 %, and 6-7, 18-22 % (estimates off chart).
Benign recurrent tia's sensory only may have more tia's but < 3 % risk of stroke.
Risk of stroke after TIA (cf slide by Brott) average of about 12 studies was about 5 % in first 2 days, 12 % in first 90 days. Kaiser and California studies were cited specifically. 1702 patients presented to California ED's received a diagnosis of TIA and were followed for three months, from record review. ABCD score was derived age > 60 (1 point), bp > 140/90 (1 point), clinical (unilateral weakness 2 points, speech disturbance without weakness one point) and duration (> 60 min, 2 points; 15 m to 60 m, 1 point) Final score 0-6 (Lancet 2005 Rothwell). OR California ABCD score (age> 60 one point, DM 1 pt, duration > 10 min 1 point,any weakness 1 pt, any speech impairment 1 pt, 0-5 score, Johnston JAMA 2000). ABCD (2) score Lancet 2007: age 1 pt, bp 1 pt, weakness/speech impairment 2/1 pts, dur >60 2 pt, 15-60 1 pt, dm 1 pt, 0-7 scale).
ABCD(2) score was validated and is ready for clinical use. 2 day risks for score (0-3) 1 %; score 4-5 (4%), score 6-7 (8%). Pct of patients in low medium and high risk groups were respectively34, 45, 21 respectively.
From Lancet article(2007) 90 day risk appears 0-3 (4 %?), score 4-5 9-13 %, and 6-7, 18-22 % (estimates off chart).
Benign recurrent tia's sensory only may have more tia's but < 3 % risk of stroke.
Consults for Stroke risk and timing of surgery
Blacker Dj et al The preoperative cerebrovascular consultation. Common cerebrovascular questions before general or cardiac surgery. Mayo Clin Proc 2004;79: 223-229.
Table one described stroke risk in various scenarios. CABG + valve surgery led with 4-13 % risk. CABG after prior stroke/TIA 8 %, CABG with carotid occlusion, 7 %, surgery with symptomatic VB stenosis, 6 %, CABG with bilateral > 50 % stenosis 5 %, unilateral 3%, after prior stroke 2.9 %, all surgery stroke risk 0.2 %. Other important factors are PVD, cardiac arrythmias, and chronic airway disease.
For CABG, prior stroke or TIA is very risky, worse with advanced age, recent MI, angina, DM smoking, impaired renal function. Authors suggest carotid surgery before CABG if dual disease, if carotid disease is symptomatic. and if carotid is not symptomatic, avoiding dual procedure (ie not doing CABG and CEA together). They also suggest waiting one month after stroke to do carotid surgery.
Table one described stroke risk in various scenarios. CABG + valve surgery led with 4-13 % risk. CABG after prior stroke/TIA 8 %, CABG with carotid occlusion, 7 %, surgery with symptomatic VB stenosis, 6 %, CABG with bilateral > 50 % stenosis 5 %, unilateral 3%, after prior stroke 2.9 %, all surgery stroke risk 0.2 %. Other important factors are PVD, cardiac arrythmias, and chronic airway disease.
For CABG, prior stroke or TIA is very risky, worse with advanced age, recent MI, angina, DM smoking, impaired renal function. Authors suggest carotid surgery before CABG if dual disease, if carotid disease is symptomatic. and if carotid is not symptomatic, avoiding dual procedure (ie not doing CABG and CEA together). They also suggest waiting one month after stroke to do carotid surgery.
Saturday, April 07, 2007
Why not trial intra-arterial lytics in basilar artery thrombosis
Article by Powers WJ. Intrarterial thrombolysis for basilar artery thrombosis. Trial it. Stroke. 2007; 38: 704-706. This article stresses the lack of current evidence in favor of arterial lytics therapy for ba thrombosis and the need for clinical trials. Macleod et al.(2005; 20: 12-17)Cerebrovascular Disease) is only randomized trial and it was prematurely terminated due to shortage of urokinase. Authors comment: "However, not every treatment requires a randomized clinical
trial to establish efficacy. Observational studies may provide
compelling evidence of treatment efficacy if treatment effects
are sufficiently large and consistent.6 Thus, the following 2
conditions must be met: (1) outcomes in untreated patients
are consistent; and (2) outcomes in treated patients are
consistently superior by a large margin. "". Lindsberg and Mattle have recently reviewed data on
344 patients from 11 different publications who were treated
with intra-arterial thrombolytic therapy for acute basilar
artery occlusion.5 Good outcome was achieved in 17% to
40% cases with a mean value of 24%. Those treated within
6 hours did not have a better outcome than those treated
after 6 hours.18,19 These values are not superior to the 30% to
67% good outcomes in patients who did not receive intraarterial
therapy reported in 4 recent hospital-based series
cited above. However, such comparisons across observational
studies are problematic because of differences in eligibility
criteria and in definitions of favorable outcome among the
different studies. In 1988, Hacke et al published an observational
study in which they compared 43 patients who receive
intra-arterial thrombolytic therapy for vertebral basilar thrombosis
to 22 historical controls from their center using the same outcome definition. significant benefit of intra-arterial thrombolysis in producing
favorable outcome (P[1]0. 017) and survival (P[1]0.0005).11
However, this conclusion was based on a flawed comparison
of 22 controls to only those 19 patients in whom successful
recanalization was achieved, not to the total group of 43 who
underwent thrombolytic therapy. This analytic approach is
not valid. Spontaneous recanalization of basilar artery occlusion
occurs in a substantial number of patients.20 Patients with
high levels of plasminogen activator inhibitors have both
reduced recanalization to exogenous thrombolytic agents and
reduced endogenous thrombolysis.21,22 Thus, selecting only
those patients with successful recanalization to exogenous
thrombolytic agents will also select those with the best
chance for spontaneous endogenous thrombolysis. Comparing
this selective subgroup to the full spectrum of control
patients will yield an invalid, overestimation of the treatment
effect. The more appropriate analysis based on the intentionto-
treat principle reveals that favorable outcome was
achieved in 10 of 43 treated patients and 3 of 22 untreated
patients (P[1]0.22). This study actually failed to demonstrate,
even with the use of historical controls, any significant benefit for intra-arterial thrombolytic therapy in this condition. "
Unfortunately, this therapy is not without either risk
or expense. The risk of symptomatic hemorrhage is 8% and
these may be fatal.5,23 Costs for thrombolytic drugs ($1000 to
$3000), cerebral arteriography ($4000 to $8000) and an intensive
care unit bed ($2300 to $3000/day) add substantial burdens
to a healthcare system that is already strained with no room to
grow.24,25,26 These procedural risks and expenses can be justified
only if the treatment is sufficiently effective to provide an
improvement in clinical outcome to outweigh the procedural
risks and a reduction in long-term costs to outweigh the
procedural expenses. In the absence of evidence for efficacy, the
procedural risks and expenses remain with nothing to outweigh
them.
trial to establish efficacy. Observational studies may provide
compelling evidence of treatment efficacy if treatment effects
are sufficiently large and consistent.6 Thus, the following 2
conditions must be met: (1) outcomes in untreated patients
are consistent; and (2) outcomes in treated patients are
consistently superior by a large margin. "". Lindsberg and Mattle have recently reviewed data on
344 patients from 11 different publications who were treated
with intra-arterial thrombolytic therapy for acute basilar
artery occlusion.5 Good outcome was achieved in 17% to
40% cases with a mean value of 24%. Those treated within
6 hours did not have a better outcome than those treated
after 6 hours.18,19 These values are not superior to the 30% to
67% good outcomes in patients who did not receive intraarterial
therapy reported in 4 recent hospital-based series
cited above. However, such comparisons across observational
studies are problematic because of differences in eligibility
criteria and in definitions of favorable outcome among the
different studies. In 1988, Hacke et al published an observational
study in which they compared 43 patients who receive
intra-arterial thrombolytic therapy for vertebral basilar thrombosis
to 22 historical controls from their center using the same outcome definition. significant benefit of intra-arterial thrombolysis in producing
favorable outcome (P[1]0. 017) and survival (P[1]0.0005).11
However, this conclusion was based on a flawed comparison
of 22 controls to only those 19 patients in whom successful
recanalization was achieved, not to the total group of 43 who
underwent thrombolytic therapy. This analytic approach is
not valid. Spontaneous recanalization of basilar artery occlusion
occurs in a substantial number of patients.20 Patients with
high levels of plasminogen activator inhibitors have both
reduced recanalization to exogenous thrombolytic agents and
reduced endogenous thrombolysis.21,22 Thus, selecting only
those patients with successful recanalization to exogenous
thrombolytic agents will also select those with the best
chance for spontaneous endogenous thrombolysis. Comparing
this selective subgroup to the full spectrum of control
patients will yield an invalid, overestimation of the treatment
effect. The more appropriate analysis based on the intentionto-
treat principle reveals that favorable outcome was
achieved in 10 of 43 treated patients and 3 of 22 untreated
patients (P[1]0.22). This study actually failed to demonstrate,
even with the use of historical controls, any significant benefit for intra-arterial thrombolytic therapy in this condition. "
Unfortunately, this therapy is not without either risk
or expense. The risk of symptomatic hemorrhage is 8% and
these may be fatal.5,23 Costs for thrombolytic drugs ($1000 to
$3000), cerebral arteriography ($4000 to $8000) and an intensive
care unit bed ($2300 to $3000/day) add substantial burdens
to a healthcare system that is already strained with no room to
grow.24,25,26 These procedural risks and expenses can be justified
only if the treatment is sufficiently effective to provide an
improvement in clinical outcome to outweigh the procedural
risks and a reduction in long-term costs to outweigh the
procedural expenses. In the absence of evidence for efficacy, the
procedural risks and expenses remain with nothing to outweigh
them.
Lack of utility of MERCI device
2007 AAN poster p06.127 p.A286 in neurology supplementBarreto et al. Adjunctive MERCI catheter utilization during intraarterial therapy does not benefit unselected ischemic stroke patients. Compared 22 patients receiving MERCI to 144 who received intraarterial therapy without merci at their center (Houston). Results-- patients receiving merci had higher recanalization but did not achieve better outcome.conclusion-- the results remain suboptimal in unselected patients indicating the need for better patient selection.
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