Jacques De Keyser

Dr. Jacques De Keyser


Research Focus & Metrics

Academic Career Length

44Years (1983-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 August 1999 in Stroke
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Journal Article
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GSGeert Sulter
Geert Sulter
CSChristel Steen
Christel Steen
JKJacques De Keyser
Jacques De Keyser
Background and Purpose —The Barthel Index (BI) and the Modified Rankin Scale (MRS) are commonly used scales that measure disability or dependence in activities of daily living in stroke victims. The objective of this study was to investigate how these scales were used and interpreted in acute stroke trials. Methods —We identified from MEDLINE the major efficacy trials with neuroprotective drugs, thrombolytic drugs, and anticoagulants in acute ischemic stroke published between January 1995 and December 1998. We selected those trials that used the BI and/or MRS as outcome parameters. Results —Fifteen trials fulfilling the inclusion criteria were identified. The BI was used in 13 and the MRS in 8. In 4 trials mean and median scores of the BI were used, and in 1 trial median scores of the MRS were compared. Primary end points included the BI in 7, the MRS in 6, and both the BI and MRS in 3. With regard to the BI, a variety of sum scores between 50 and 95 were used as cutoff scores to define favorable outcome. Favorable outcome on the MRS was defined as either ≤1 or ≤2. Conclusions —Among the efficacy trials in acute stroke, we found remarkable differences in the choice of primary end points and in the definition of favorable outcome on both the BI and MRS. This lack of consensus strongly hinders the design, interpretation, and comparison of acute stroke trials. In general, it may be easier to define poor outcome instead of favorable outcome. Poor outcome could be defined if any of the following end points are reached: death, institutionalization due to stroke, MRS >3, or BI <60.

18 September 2008 in New England Journal of Medicine
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Journal Article
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RSRalph L. Sacco
Ralph L. Sacco
HDHans-Christoph Diener
Hans-Christoph Diener
SYSalim Yusuf
Salim Yusuf
DCDaniel Cotton
Daniel Cotton
SÔStephanie Ôunpuu
Stephanie Ôunpuu
BYByung-Woo Yoon
Byung-Woo Yoon
Recurrent stroke is a frequent, disabling event after ischemic stroke. This study compared the efficacy and safety of two antiplatelet regimens — aspirin plus extended-release dipyridamole (ASA–ERDP) versus clopidogrel. In this double-blind, 2-by-2 factorial trial, we randomly assigned patients to receive 25 mg of aspirin plus 200 mg of extended-release dipyridamole twice daily or to receive 75 mg of clopidogrel daily. The primary outcome was first recurrence of stroke. The secondary outcome was a composite of stroke, myocardial infarction, or death from vascular causes. Sequential statistical testing of noninferiority (margin of 1.075), followed by superiority testing, was planned. A total of 20,332 patients were followed for a mean of 2.5 years. Recurrent stroke occurred in 916 patients (9.0%) receiving ASA–ERDP and in 898 patients (8.8%) receiving clopidogrel (hazard ratio, 1.01; 95% confidence interval [CI], 0.92 to 1.11). The secondary outcome occurred in 1333 patients (13.1%) in each group (hazard ratio for ASA–ERDP, 0.99; 95% CI, 0.92 to 1.07). There were more major hemorrhagic events among ASA–ERDP recipients (419 [4.1%]) than among clopidogrel recipients (365 [3.6%]) (hazard ratio, 1.15; 95% CI, 1.00 to 1.32), including intracranial hemorrhage (hazard ratio, 1.42; 95% CI, 1.11 to 1.83). The net risk of recurrent stroke or major hemorrhagic event was similar in the two groups (1194 ASA–ERDP recipients [11.7%], vs. 1156 clopidogrel recipients [11.4%]; hazard ratio, 1.03; 95% CI, 0.95 to 1.11). The trial did not meet the predefined criteria for noninferiority but showed similar rates of recurrent stroke with ASA–ERDP and with clopidogrel. There is no evidence that either of the two treatments was superior to the other in the prevention of recurrent stroke. (ClinicalTrials.gov number, NCT00153062.)

18 September 2008 in New England Journal of Medicine
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Journal Article
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SYSalim Yusuf
Salim Yusuf
HDHans-Christoph Diener
Hans-Christoph Diener
RSRalph L. Sacco
Ralph L. Sacco
DCDaniel Cotton
Daniel Cotton
SÔStephanie Ôunpuu
Stephanie Ôunpuu
BYByung-Woo Yoon
Byung-Woo Yoon
Prolonged lowering of blood pressure after a stroke reduces the risk of recurrent stroke. In addition, inhibition of the renin–angiotensin system in high-risk patients reduces the rate of subsequent cardiovascular events, including stroke. However, the effect of lowering of blood pressure with a renin–angiotensin system inhibitor soon after a stroke has not been clearly established. We evaluated the effects of therapy with an angiotensin-receptor blocker, telmisartan, initiated early after a stroke. In a multicenter trial involving 20,332 patients who recently had an ischemic stroke, we randomly assigned 10,146 to receive telmisartan (80 mg daily) and 10,186 to receive placebo. The primary outcome was recurrent stroke. Secondary outcomes were major cardiovascular events (death from cardiovascular causes, recurrent stroke, myocardial infarction, or new or worsening heart failure) and new-onset diabetes. The median interval from stroke to randomization was 15 days. During a mean follow-up of 2.5 years, the mean blood pressure was 3.8/2.0 mm Hg lower in the telmisartan group than in the placebo group. A total of 880 patients (8.7%) in the telmisartan group and 934 patients (9.2%) in the placebo group had a subsequent stroke (hazard ratio in the telmisartan group, 0.95; 95% confidence interval [CI], 0.86 to 1.04; P=0.23). Major cardiovascular events occurred in 1367 patients (13.5%) in the telmisartan group and 1463 patients (14.4%) in the placebo group (hazard ratio, 0.94; 95% CI, 0.87 to 1.01; P=0.11). New-onset diabetes occurred in 1.7% of the telmisartan group and 2.1% of the placebo group (hazard ratio, 0.82; 95% CI, 0.65 to 1.04; P=0.10). Therapy with telmisartan initiated soon after an ischemic stroke and continued for 2.5 years did not significantly lower the rate of recurrent stroke, major cardiovascular events, or diabetes. (ClinicalTrials.gov number, NCT00153062.)

1 November 2010 in Stroke
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Journal Article
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MAMarcel J.H. Aries
Marcel J.H. Aries
JEJan W. Elting
Jan W. Elting
JKJacques De Keyser
Jacques De Keyser
BKBerry P.H. Kremer
Berry P.H. Kremer
PVPatrick C.A.J. Vroomen
Patrick C.A.J. Vroomen
Background and Purpose— Cerebral autoregulation may become impaired after stroke. To provide a review of the nature and extent of any autoregulation impairment after stroke and its course over time, a technique allowing repeated bedside measurements with good temporal resolution is required. Transcranial Doppler (TCD) in combination with continuous blood pressure measurements allows noninvasive continuous bedside investigation with high temporal resolution of the dynamic and the steady-state components of cerebral autoregulation. Therefore, this review focuses on all TCD studies on cerebral autoregulation in the setting of documented ischemic stroke. Methods— PubMed and EMBASE were searched for studies of stroke, autoregulation, and TCD. Studies were either acute phase (96 hours after index stroke) autoregulation studies. Quality of studies was studied in a standardized fashion. Results— Twenty-three studies met the inclusion criteria. General agreement existed on cerebral autoregulation being impaired, even after minor stroke. Bilateral impairment of autoregulation was documented, particularly after lacunar stroke. Studies showed progressive deterioration of cerebral autoregulation in the first 5 days after stroke and recovery over the next 3 months. Impaired cerebral autoregulation as assessed by TCD was related to neurological deterioration, the necessity for decompressive surgery, and poor outcome. Synthesis of the data of various studies was, however, limited by studies not meeting key methodological criteria for observational studies. Conclusions— TCD in combination with continuous blood pressure measurement offers a method with a high temporal resolution feasible for bedside evaluation of cerebral autoregulation in the stroke unit. TCD studies have shown impairment of cerebral autoregulation in various subtypes of ischemic stroke. To improve the synthesis of data from various research groups, there is urgent need for standardization of methodology of TCD studies in cerebral autoregulation.

1 October 2008 in The Lancet Neurology
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Journal Article
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HDHans-Christoph Diener
Hans-Christoph Diener
RSRalph L Sacco
Ralph L Sacco
SYSalim Yusuf
Salim Yusuf
DCDaniel Cotton
Daniel Cotton
SÔStephanie Ôunpuu
Stephanie Ôunpuu
BYByung-Woo Yoon
Byung-Woo Yoon

1 June 2011 in Brain Research Reviews
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Journal Article
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ASAnneleen Spooren
Anneleen Spooren
KKKrzysztof Kolmus
Krzysztof Kolmus
GLGuy Laureys
Guy Laureys
RCRalph Clinckers
Ralph Clinckers
JKJacques De Keyser
Jacques De Keyser
SGSarah Gerlo
Sarah Gerlo