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[Risk factors for cerebrovascular stroke in a cohort of hypertensive patients]
E Rocha1, A Gouveia-Oliveira, A Cotter
1Centro de Estudos de Cardiologia Preventiva, INSA, Lisboa.
Insights
Age, diabetes, high diastolic blood pressure, and left ventricular hypertrophy are key stroke risk factors in hypertensive patients. Controlling these factors is crucial for stroke prevention in this population.
Area of Science:
- Cardiology
- Neurology
- Epidemiology
Context:
- Hypertension is a major risk factor for stroke.
- Understanding specific risk factors is crucial for targeted prevention strategies.
- Longitudinal studies provide valuable insights into disease progression and risk stratification.
Purpose:
- To identify significant stroke risk factors in patients with hypertension.
- To determine the probability of stroke in relation to identified risk factors.
- To analyze the impact of various clinical and demographic variables on stroke incidence.
Summary:
- A cohort study of 598 hypertensive patients followed from 1975 to 1992 identified key stroke risk factors.
- Significant risk factors included advanced age, diabetes mellitus, diastolic blood pressure exceeding 114 mmHg, and left ventricular hypertrophy.
- The study utilized multivariate analysis (Cox regression) to determine adjusted relative risks and Kaplan-Meier methods for survival probability.
Impact:
- Identified modifiable and non-modifiable risk factors for stroke in hypertensive individuals.
- Highlights the importance of blood pressure and diabetes management for stroke prevention.
- Suggests the need for further research to fully elucidate the stroke risk profile in hypertensive patients.
Objectives:
To identify stroke risk factors in hypertensive patients and the probability of stroke in relation to those risk factors and follow-up.
Study Design:
A cohort study (patients with high blood pressure).
Material And Methods:
707 hypertensive patients were studied (Hypertension Register) in what concerns stroke incidence until 1992 (n = 126), considering one case per individual. The following variables were analysed: age, sex, body mass index (Quetelet), systolic and diastolic blood pressure, heart rate, types of hypertension (JNC-IV), left ventricular hypertrophy, changes in ST segment and T wave (Minnesota Code), fundi, angina pectoris, heart failure, central nervous (neurological) disturbances, antihypertensive treatment, smoking, serum potassium, serum sodium, blood urea, creatinine, uric acid, blood sugar, diabetes and cholesterol, in the initial record. Individually, in relation to the control of hypertension, the subjects were classified according to the casual recording of normal blood pressure, the absence of drug treatment, diastolic pressure > 114 mmHg and, at the end of 1992, according to survival, causes of death and follow-up. Stroke risk factors have been identified by multivariate analysis (Cox regression model). The survival probability (without stroke) was defined by Kaplan-Meier method.
Results:
It was possible to maintain the epidemiological surveillance, from 1975 to 1992, of 598 cases. From those, 109 hypertensive patients were victims of at least one episode of non transient cerebral ischaemia, during their follow-up of 10.5 years. From the characteristics studied, only five were identified at risk factors. The adjusted relative risks and confidence intervals (95% CI) were the following: age: 1.08 (1.06-1.10); diastolic pressure > 114 mmHg: 1.96 (1.32-2.91); neurological disturbances 4.64 (2.99-7.2); diabetes: 2.57 (1.62-4.05) and left ventricular hypertrophy: 1.34 (1.13-1.58).
Conclusions:
As far as stroke is concerned: a) Age, diabetes, a casual measurement of diastolic blood pressure > 114 mmHg and left ventricular hypertrophy (electrocardiogram) were the risk factors identified; b) Prevention should include blood pressure and diabetes control, although this disease has shown more risk than a casual measurement of severe hypertension; c) Its occurrence, in this model, has only partly been explained, therefore it has become necessary to deepen the study of the risk profile.