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The J-curve phenomenon in stroke recurrence
K Irie1, T Yamaguchi, K Minematsu
1Cerebrovascular Division, National Cardiovascular Center, Osaka, Japan.
Insights
Lowering blood pressure after stroke doesn't always prevent recurrence. A J-curve relationship exists between poststroke diastolic blood pressure and stroke recurrence, indicating an optimal range for better outcomes.
Area of Science:
- Neurology
- Cardiovascular Medicine
- Epidemiology
Background:
- The relationship between poststroke blood pressure and stroke recurrence is not fully understood.
- Optimal blood pressure targets for stroke survivors remain undefined.
Purpose of the Study:
- To investigate the association between poststroke blood pressure levels and the risk of recurrent stroke.
- To determine if a specific blood pressure range is associated with lower stroke recurrence rates.
Main Methods:
- Analysis of 368 hypertensive stroke patients observed for at least 6 months.
- Evaluation of stroke recurrence rates based on baseline and poststroke blood pressure, stroke subtypes, age, and antihypertensive treatment.
Main Results:
- A J-curve relationship was observed between poststroke diastolic blood pressure and stroke recurrence.
- The lowest recurrence rate (3.8% per patient-year) occurred with diastolic blood pressure between 80-84 mm Hg.
- Optimal diastolic blood pressure ranges varied by stroke subtype (atherothrombotic vs. lacunar infarction).
Conclusions:
- Lowering blood pressure poststroke may not consistently reduce recurrence risk.
- The J-curve phenomenon complicates the effects of poststroke blood pressure and antihypertensive therapy on recurrence.
Background And Purpose:
The relation of poststroke blood pressure to stroke recurrence remains undetermined, and the optimal control of blood pressure has not been established. We performed the present study to resolve these issues.
Methods:
We analyzed 368 stroke patients with a history of hypertension (mean age, 62 years) who were admitted within 3 months after stroke onset and observed for 6 months or more. We determined stroke recurrence rate in relation to baseline (or initial) blood pressure, mean values of poststroke blood pressure, stroke subtypes, age, antihypertensive treatment, and other clinical features.
Results:
The recurrence rate had a J-curve relation to poststroke diastolic blood pressure but not to poststroke systolic blood pressure and baseline diastolic and systolic blood pressures. The stroke recurrence rate was 3.8% per patient-year in 94 patients who had a poststroke diastolic blood pressure of 80 to 84 mm Hg, significantly lower than the rates of 9.2% per patient-year (P < .05) and 11.4% per patient-year (P < .01) in those with a lower and higher poststroke diastolic blood pressure, respectively. The range of poststroke diastolic blood pressure accompanying the lowest stroke recurrence rate was higher in patients with atherothrombotic (85 to 89 mm Hg) than in those with lacunar infarction (80 to 84 mm Hg). Neither antihypertensive therapy nor patients' age affected this phenomenon.
Conclusions:
The present study suggests that lower blood pressure does not always result in favorable effects on stroke recurrence. The effects of poststroke blood pressure and antihypertensive therapy on stroke recurrence may be complicated by the J-curve phenomenon.