Types of Recurrent Stroke in Survivors of Intracerebral Hemorrhage
To the Editor:
I read with great interest the recent article1 by Arakawa and colleagues. In this important study, Arakawa and colleagues followed up 74 patients with hypertensive brain hemorrhage for a mean of 2.8 years and reported higher diastolic blood pressure (DBP) but not higher systolic blood pressure (SBP) as the risk factor for recurrent brain hemorrhage. I would make the following comments.
First, recurrent stroke affected 9 of the 74 patients; the type of recurrent stroke was intracerebral hemorrhage (ICH) in 8 (89%) and ischemic stroke (IS) in 1 (11%).1 Although most of the recurrent strokes are of the same type as the first episode in patients surviving from IS, this may not apply to survivors of ICH. In a study by Yamamoto and Bogousslavsky,2 the recurrent strokes were of the same type as the initial strokes in 77% of patients with cardioembolic IS, 65% with nonlacunar noncardioembolic IS, 58% with ICH, and 48% with lacunar IS. I wonder whether Arakawa and colleagues have any explanation for the high consistency rate of 89% of recurrent ICH observed in their cohort. From our database of information prospectively gathered between October 1996 and January 1999 (Cheung, unpublished data, 1999), 138 of 607 stroke patients had a previous history of stroke. Of 120 patients with a previous history of IS, the type of recurrent stroke was IS in 108 (90%) and ICH in 12 (10%). Of 16 patients with a previous history of ICH, the recurrent stroke was ICH in 5 (31%) and IS in 11 (69%). Two patients had a history of subarachnoid hemorrhage; one had a recurrent ICH and the other a recurrent IS.
Second, arterial blood pressure was monitored monthly in the cohort of 74 patients, and the mean values of SBP and DBP were used in the analysis.1 I would like to know the range of the SBP and DBP in the 2 subgroups of patients as defined by the recurrent ICH. In addition, I wonder whether the SBP and DBP values were greater in the period immediately before the recurrent ICH, suggesting a close temporal relationship between blood pressure control and recurrent ICH.
- Copyright © 1999 by American Heart Association
We would like to thank Dr Cheung for his critical comments on our study.R1
As has been pointed out by Dr Cheung, the recurrent stroke was predominantly hemorrhagic in our series of patients with brain hemorrhage, and the rate (89%) was rather higher than those reported in previous studies.R2 R3 R4 However, the reported rates distribute in a wide range (Cheung, unpublished data, 31%; Passero et al,R2 65%; Yamamoto and Bogousslavsky,R3 58%; Kumamoto et al,R4 81%). The variation probably results from a relatively small number of samples and events in each study (number of samples, 74 to 143; events, 9 to 27). Under such circumstances, even the occurrence of 1 ischemic event would affect the result considerably. Second, judging from the reports by Kumamoto et alR4 and our own,R1 the Japanese may show a higher rate of hemorrhagic recurrence. Another plausible explanation for the variation is that some ischemic strokes (in particular, lacunar infarction) can be asymptomatic and may have been overlooked in some studies, including ours; we did not try to detect asymptomatic strokes systematically. Finally, the levels of blood pressure during the follow-up period is likely to influence the type of recurrence. Excessive antihypertensive medication promotes the occurrence of ischemic stroke in some patients, especially those with major cerebral arterial diseases. We make it a clinical rule to avoid the rapid and excessive control of poststroke blood pressure. In addition, major cerebral arterial diseases are less common in Japan than Western countries, although they are increasing in number. These conditions may have resulted in the higher recurrence rate of hemorrhagic stroke in our series of patients.
The range of blood pressure in our study was 125 to 149/75 to 96 mm Hg and 113 to 158/64 to 97 mm Hg for the recurrence and nonrecurrence groups, respectively. The average blood pressure measured immediately before rebleeding was 135/89 mm Hg in the recurrence group. The value was comparable to that during the follow-up period (P>0.05).
Arakawa S, Saku Y, Ibayashi S, Nagao T, Fujishima M. Blood pressure control and recurrence of hypertensive brain hemorrhage. Stroke.. 1998;29:1806–1809.
Passero S, Burgalassi L, D’Andrea P, Battistini N. Recurrence of bleeding in patients with primary intracerebral hemorrhage. Stroke.. 1995;26:1189–1192.
Yamamoto H, Bogousslavsky J. Mechanisms of second and further strokes. J Neurol Neurosurg Psychiatry.. 1998;64:771–776.
Kumamoto I, Nomoto M, Ohkatsu Y, Igata A. Recurrence of cerebral thrombosis and cerebral hemorrhage. Jpn J Stroke.. 1985;7:180–185.