Thursday, May 24, 2007

Pillcam contraindicated in stroke alert

I have been asked twice this week regarding the safety and efficacy of the PillCam used to evaluate the esophagus and/or the intestinal track. These devices are highly contraindicated for any MRI procedure. Being within the vicinity of an MR system alters the operation, patient are at risk for RF burns if put inside an MR system.  I have included information from the manufacturers website (contraindications in bold and underlined). I will be forwarding this information to all the techs corporately as well.



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Saturday, May 19, 2007

Clinical Trials: DIAS

DIAS-- desmoteplase in acute ischemic stroke -- placebo controlled, double blind, dose-finding randomized Phase II trial designed to evaluate safety and efficacy of desmoteplase. Looked at patients presenting 3-9 hours, enrolled 2001-2003 104 patients with NIHSS of 4-20 and mismatch on perfusion/diffusion imaging. Doses were 25, 37.5, and 50 mg of drug given as an iv bolus over two minutes. Due to excess symptomatic ICH lower doses were investigated in part 2 (62.5, 90 and 125 ug/kg). Safety outcome was rate of sICH, efficacy outcome measures were rate of reperfusion after 4-8 hours and NIHSS, mRS and Barthel at 90 days. In part excess s ICH was seen (23-30 % all within 24 hours). In part 2, the rate of sICH was 2.2%. In part 2 rates of reperfusion UP TO 71.4 % were seen at 125 ug dose compared to 19.2 % with placebo. Good clinical outcome was seen in 22 % of placebo treated patients and 13.3-60 % of drug treated patients (proportional to higher dose) also corresponding with early reperfusion. Overall 52 % of patients with reperfusion had favorable outcome v 24.6 % without.

Conclusions-- DIAS showed iv lysis is safe at 3-9 hours in patients with mismatch on MRI and dose dependent reperfusion correlated with clinical outcome. Outcome at 6-9 hours was as good as 3-6 hours. A phase 3 trial comparing 90 and 125 ug / kg doses in ongoing.

Clinical trials ECASS III and IST III

Background-- pooled data from earliir ATLANTIS ECASS AND NINDS trials, published in 2002 suggested good outcomes for subjects treated within 180 minutes, with a trend to improved outcomefrom 180-270 minutes, and little benefit beyond 270 minutes.

ECASS III (European Cooperative Acute Stroke Study) in an ongoing trial begun in 2003 of alteplase started from 3-4 hours after stroke onset. Leader Werner Hacke. Later changed to 3-4.5 hours to help recruitment. Primary endpoints are mRS, Barthel and NIHSS at 90 days. Will end in summer of 2007?

IST III (International Stroke Trial) plans to enroll 6000 patients to see if alteplase within six hours increases proportion of independent survivors at six months. It also wants to see which categories benefit most from treatment. Placebo controlled.

Stroke Trials CLOTBUST

Ultrasound enhanced thrombolysis-- u/s can help diagnose clot, monitor thrombolysis and increase t-Pa binding to thrombin. CLOTBUST-- combined lysis of thrombus in brain ischemia using transcranial ultrasound and systemic rt-PA. 2001-4 Texas-Houston, 126 patients enrolled. All patients received alteplase within guidelines and half got TCD monitoring, the other half placebo monitoring. Half (49 %) of treatment group reached endpoint of complete recanalization or dramatic clinical recovery (NIHSS of 3 or less) within 2 hours, compared to 30 % of controls. At 3 months 42-29 % favoring treatment had mRankins of 0 or 1. Three subjects in each group had ICH. Authors concluded that arterial recanalization was augmented by TCD.

Complications of Rx for Subclavian stenosis

( a benign disease)
transthoracic or extrathoracic bypass

Horner's s
phrenic palsy
pleural effusion
chylothorax
cervical lymph fistula
infection
hemorrhage

In a revie of 2496 patients, the surgical complication rate was 16 %, stroke rate 3 %, mortality rate of 2 %.

Angioplasty is better in this disease with major technical success and low rate of complications.

Clinical trials for stenting: CAVATAS, SAPPHIRE

CAVATAS carotid and vertebral artery transluminal angioplasty study-- large prospective randomized trial oo CEA v. carotid angioplasty. Criteria-- symptommtic stenosis > 70 %. Surgical candidates were randomized to angioplasty or stent. Nonsurgical candidates were randomized to angioplasty v. best medical treatment. In first group, 504 patients were randomized and the differences were nonexistent. In both the surgical and angioplasty group, the rate of any stroke lasting more than a week or death in first 30 days was 10 % The rate of disabling stroke or death in first 30 days was 6 % for each. The rate of restenosis was twice as great in the endovascular cohort v. the surgical group, 18 v. 9 %.

SAPHIRE-- stenting and angioplasty with protection in patients at high risk for endarterectomy-- compared stenting with protection v. CEA in surgically high risk patients with comorbidities. Enrolled 747 patients with > 50 % symptomatic stenosis or > 80 % asymptomatic stenosis. Stenting with a dis: tal protection device was not inferior and narrowly missed superiority. The risk of stroke, death oo MI was 39 % lower with stenting at 30 days. The risk of ipsilateral stroke was 7.9 % lower at one year. Critiques: 1) a high number, 55 % were excluded due to "surgical risk." 2) 20 % had restenosis after prior CEA 3) Inclusion of MIi as an endpoint obscures cerebrovascular data.

Ongoing trials:
EVA 3S Endarterectomy v. angioplasty in severe carotid stenosis
ARCHeR-2 (Acculink)
ICSS= CAVATAS 2 compares stent v. CEA in high risk group
SPACE -Stent protected percutaneous angioplasty of the carotid v endarterectomy 1900 patients, German study
CREST

Who is at risk for further stroke? MRI factors

Minor stroke or TIA with a lesion on DWI and and large artery stenosis had a 32 % chance of recurrence within 90 days (v. 11% with DWI alone and 4 % with neither finding) (Coutts SB et al. Ann Neurol 2005; 57:848-854)

Patients imaged within 24 hours who had DWi lesions with differing ADC values (implying different lesion ages) were more likely to develop recurrent stroke at 30 days v. those with DWIi lesions but nonvariable ADC (relative risk 3.6). Patients with cardioembolic source had a higher probability of having new DWI lesions on followup MRI (odds ratio 3.2). ( Sylaja et al. Neurology 2007; 68:415-419.

Subarachnoid hemorrhage scales

Hunt Hess (Neurosurgery 1998)
Grade Clinical Condition
0 Unruptured
1 asymptomatic or minimal headache/nuchal rigidity
2 Mod/severe headache, nuchal rigidity, no neuro deficit except CN palsy
3 drowsy confused, mild focal deficit
4 stupor, moderate/severe hemiparesis, possible early decerebrate
5 deep coma


Fisher scale (based on CT) (Neurology 1980)
Score Description
1 No blood
2 diffuse deposition or vertical layers <1 mm thick, no clots
3 localized clot and/or vertical layers > 1 mm thick
4 intracerebral or intraventricular clots with diffuse or no blood


Ogilvy Carter System for prognosis (Neurosurgery 1998; 42:959-970)

Points Description
1 Hunt Hess grade > 3
1 Fisher score > 2
1 Aneurysm size > 10 mm
1 Age > 50
1 Giant (> 25 mm) posterior circulation location

Sunday, May 06, 2007

Stroke protocols per AAN meetings

Candidate selection for intervention level 2 evidence
 
1) Patients  inelegible for iv tPA within 6 hours use lytics, within 8 hours, MERCI
2) Consider longer duration for posterior circulation disease
3)  Use of DWI'PWI mismatch for patients beyond standard time windows.
 
Within 3 hours patients with ICA, MCA, BA occlusion, patients that fail to respond to IV tPA, or are excluded by NINDS iv exclusion criteria are candidates for intervention
 
3-6 hours patients with DWI/PWI mismatch are candidates for arterial
 
6-8 hours MERCI candidates
>8 hours for posterior circulation
 
Intervention
10 % vessels are open
first use 22-25 mg tPA inside clot
then go to stenting if reperfuse great
 
if don't reperfuse go to clot retrieval.
 
 




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Recanalization after iv tpa-- MCA v. ICA

(Beth Israel, Boston) Lanfante et al, Stroke 2002.
 
This is not a summary of the article but presentation of a few facts pulled out from it.  With initial NIHSS score of 16 or above most do not recanalize with iv tpa.  At NIH of 14 or below, MCA strokes recanalize much better than ICA strokes.Outcome correlates closely with recanlization. 
 
Christou et al showed that recanalization after iv tpa in 60 patients  with TIMI 2 or 3, 80 % MCA recanalized, 25 % ICA, 19% MCA-ICA, 7 % BA recanalized.
 
Frequency of iv tpa use:  national estimate is 1-2%.  30,000 ischemic strokes per month, 500 get iv tpa, 29,500 do not.
 
There are 3 categories of patients to consider.  1)  Those excluded from iv tpa (time,recent stroke, 2 weeks surgery, trauma, coagulopathy or INR>1.7)   2)  Nonresponders   3)  Reooclusion after initial reperfusion.
 
Mechanical reperfusion-- no thrombolytics used to reduce chance of bleeding (MERCI 1st and 2d generation, angioplasty and stenting). "Requires a learning curve."  Soft clots don't respond as well.
 
MultiMERCI
use of iv tPA allowed, newer device MERCI 1.5
mean age 66, baseline NIHSS 19, 34 %mRS <2 90 days, 30 % mortality at 90 days, 9 % SICH, 10 % procedure related SAE's (dissection, vessel perforation, distal embolization).  Comment one third get better whereas they had been doomed to death or disability previously.  Across trials all had about one third good outcome by mRS.
 
Patient selection:
How to select patients better.
MR rescue up to 8 hours




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MERCI 1 notes

mean age 67 NIHSS 20, mean time stroke onset to groin puncture 4.3 hours, 38 % enrolled within 3 hours, mean procedure time 2 hours, device passes 2.9 7.8 % SICH, 11 device fractures, 2 contributing to mortality. Mortality was 43 %, partly due to perforation with device malfunction.
 

MERCI I subgroup anal

Post circ n=14

ICA n=47

Mca n=80

Revasc

50%

53

45

Favorable 90 day mRS

36

24

29

Favorable 90 day NIHSS

50

33

29

Mortality

43

51

39

 
 

Clinical Trials Comparison

 

NINDS

                 Controls

PROACT 2

                 Controls              

IMS

MERCI

Patients

168

165

121

59

80

141

Window (hours)

0-3

0-3

0-6

0-6

0-3

0-8

BaseNIHSS

14

15

17

17

18

20

Timi 2-3

 

 

66

18

56

46

sICH

6

1

10

2

6

8

mRS 0-1

31

26

26

7

30

 

mRS 0-2

39

28

40

25

43

23

Death %

21

24

25

27

16

43

 

 

 

 

 

 

 





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Trials of interventional therapies for stroke (select)

Proact 2    ia prourokinase
474 screening angiograms, 180 randomized, mean age 64, NIHSS 17, all MCA occlusions 2:1 ratio placebo controlled,all patients received low dose heparin.  MRS<=2 at 90 days was 40 % in pro UK group v. 25 % placebo, 15 % absolute benefit, mortality (pro UK) 25 % v. (placebo) 27 %. NTT for 1 benefit =7.  Not approved due to high rate of ICH.
 
IMS  Study  Bridging therapy  eg. .6 mg/kg iv tpa (15 % bolus) followed by ia tpa up to 22 mg over 2 hours, ages 18-80, NIHSS>=10 within 3 hours.  Primary outcome safety SICH, clinical outcome mRS 0-1 at 3 months.  28/77 (36%) had major occlusion or high grade ICA stenosis, but 56 % were TIMI 2 or 3 at end of 2 hours of infusion.
 
IMS 2 - 3 ongoing multicenter randomized trial with similar design except that coull use iv tPA.endovascular (IA, MERCI, or ultrasound lysis) v. iv tPA alone.
 
 




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