Published online before print October 14, 2004, doi: 10.1161/01.STR.0000145486.71701.8c
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(Stroke. 2004;35:2436.)
© 2004 American Heart Association, Inc.
Letters to the Editor |
Association Between Pulse Pressure Values During the Acute Stroke Stage and Stroke Outcome
Acute Stroke Unit, Department of Clinical Therapeutics, University of Athens, Athens, Greece
Department of Neurology, University of Athens, Athens, Greece
To the Editor:
We read with great interest the recent Research Report by Aslanyan et al.1 The authors reported that elevated weighted average pulse pressure (PP) during the first 60 hours of ischemic stroke was independently associated with poor outcome assessed by mortality, Barthel index, National Institutes of Health Stroke Score and modified Rankin Scale score. Elevated baseline PP was associated with Barthel Index and Rankin score but not with mortality. Weighted average PP was the only blood pressure (BP) component to be consistently associated with all outcome measures.
We have also evaluated the prognostic value of the different BP components in 198 patients with acute stroke (146 cases with cerebral infarction and 42 cases with intracerebral hemorrhage) by means of 24-hour BP-monitoring.2 Our results indicated an independent association between increasing 24-hour PP levels and 1-year mortality after correcting for stroke risk factors, stroke subtypes, clinical (stroke severity and level of consciousness) and radiological characteristics (brain edema, mass effect and hemorrhagic transformation). Higher PP levels on hospital admission were related to an increased risk of 1-year mortality on univariate analysis, but in the multivariate Cox-regression model this association did not retain its statistical significance. This finding underlines the superiority of 24-hour BP variables over admission BP measurements in predicting stroke outcome. It is in keeping with the results of Aslanyan et al and other investigators, which indicate that variables describing BP course during the acute stroke period, such as 24-hour,2,3,4 beat-to-beat5 and weighted average1 BP recordings correlate more strongly and independently with stroke outcome.
On the other hand, other studies failed to document any association between PP levels in acute stroke and early5 or late outcome.4 Since, antihypertensive medication have been shown to have a differential effect on conduit vessel stiffness and to selectively alter the different BP components,6–8 we believe that the prognostic impact of PP levels at baseline and especially during the first hours of ictus on stroke outcome needs further clarification. An increasing body of evidence suggests that raised BP levels following acute stroke may not be a benign phenomenon and are associated with adverse prognosis.9 However, before embarking in a large randomized, placebo-controlled trial the question of whether the lowering of the pulsatile, the steady or both BP components in acute stroke might improve outcome remains to be answered.
References
1. Aslanyan S, Weir CJ, Lees KR; GAIN International Steering Committee and Investigators. Elevated pulse pressure during the acute period of ischaemic stroke is associated with poor stroke outcome. Stroke. 2004; 35: e153–e155.
2. Vemmos KN, Tsivgoulis G, Spengos K, Manios E, Daffertshofer M, Kotsis V, Lekakis JP, Zakopoulos N. Pulse pressure in acute stroke is an independent predictor of long-term mortality. Cerebrovasc Dis. 2004; 18: 30–36.[CrossRef][Medline] [Order article via Infotrieve]
3. Robinson T, Waddington A, Ward-Close S, Taub N, Potter J. The predictive role of 24-hour compared to casual blood pressure levels on outcome following acute stroke. Cerebrovasc Dis. 1997; 7: 264–272.
4. Robinson TG, Dawson SL, Ahmed U, Manktelow B, Fortherby MD, Potter JF. Twenty-four hour systolic blood pressure predicts long-term mortality following acute stroke. J Hypertens. 2001; 19: 2127–2134.[CrossRef][Medline] [Order article via Infotrieve]
5. Dawson SL, Manktelow BN, Robinson TG, Panerai RB, Potter JF. Which parameters of beat-to-beat blood pressure and variability best predict early outcome after acute ischemic stroke? Stroke. 2000; 31: 463–468.
6. Safar ME, van Bortel LM, Struijker-Boudier HA. Resistance and conduit arteries following converting enzyme inhibition in hypertension. J Vasc Res. 1997; 34: 67–81.[Medline] [Order article via Infotrieve]
7. Heesen WF, Beltman FW, Smit AJ, May JF, de Graeff PA, Havinga TK, Schuurman FH, van der Veur E, Meyboom-de Jong B, Lie KI. Effect of quinapril and triamterene/hydrochlorothiazide on cardiac and vascular end-organ damage in isolated systolic hypertension. J Cardiovasc Pharmacol. 1998; 31: 187–194.[CrossRef][Medline] [Order article via Infotrieve]
8. Ting CT, Chen CH, Chang MS, Yin FC. Short- and long-term effects of antihypertensive drugs on arterial reflections, compliance, and impedance. Hypertension. 1995; 26: 524–530.
9. Willmot M, Leonardi-Bee J, Bath PM. High blood pressure in acute stroke and subsequent outcome: a systematic review. Hypertension. 2004; 43: 18–24.
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