STROKE PATIENTS WITH AND WITHOUT HYPERTENSION: METHODS
Demographics and Cardiovascular Factors
The database for this analysis was the AAASPS. AAASPS is an ongoing NIH-spon-sored, multi-center, randomized, double-blind clinical trial designed to compare the effect of ticlopidine and aspirin in the prevention of recurrent stroke, myocardial infarction, and vascular death in AAs with recent, noncardioembolic ischemic stroke. Eligibility criteria for the study have been reviewed previously in the AAASPS clinical trial design paper. All enrollees identified themselves as being African American. In brief, these were African American non-car-dioembolic ischemic stroke patients entered from seven to ninety days of the onset stroke. At baseline, age, sex and income level were ascertained. In addition, past medical history of the following risk factors was ascertained: htn, diabetes mellitus, hypercholesterolemia, myocardial infarction, angina pectoris, congestive heart failure, atrial fibrillation, valvular heart disease, leg claudication, cardiac surgery, carotid endarterectomy, peripheral arterial vascular surgery and thoracic or abdominal aortic surgery.
Hypertension was defined as the history of hypertension requiring treatment by diet and/or medications, or either systolic or diastolic blood pressure elevated to > 139/89 mmHg. It was defined as a random (non-fasting) plasma glucose > 200 mg/dl (> 11.1 mmol/1), fasting venous or capillary whole blood glucose > 119 mg/dl (> 6.7 mmol/1), venous plasma glucose > 139 mg/dl (> 7.8 mmol/1) or a history of diabetes mellitus requiring treatment with diet, oral hypoglycemic or insulin. Hypercholesterolemia was defined as the history of hypercholesterolemia requiring treatment with diet and/or medication or fasting plasma cholesterol > 200 mg/dl.
The diagnosis of acute non-fatal myocardial infarction (MI) was based on having an evolving Q-wave alone, defined as Q and QRS patterns 1-1-1 through 1-2-5 or 1-2-7 by Minnesota ECG codes, or a diagnostic Q wave plus cardiac pain. Myocardial infarction was also defined as a diagnostic Q wave plus abnormal enzymes, defined as a CPK MB fraction greater than or equal to 10% of the total CPK in the absence of recognizable non-ischemic causes for elevated serum enzyme levels (i.e., cardiac surgery, electrical cardioversion, severe muscle trauma, rhabdomyolysis, etc.), LDH1/LDH2 ratio in excess of 1 without evidence of hemolysis, either total CPK, LDH or SGOT twice the upper limit of normal without a known nonischemic cause for the elevated CPK or hemolysis, or appropriate elevation of troponin. Finally, abnormal serum enzymes plus cardiac pain, defined as chest or equivalent pain occurring anywhere in the anterior chest, left arm or jaw, without a definite non-cardiac cause, also qualified as a diagnosis of ML.
Angina pectoris was classified as being stable and having chest discomfort (retrosternal pain, heaviness or pressure) radiating to the neck, jaw, shoulder or arms which could be induced by precipitating factors such as exertion and was frequently associated with dyspnea, nausea, vomiting, diaphoresis, palpitations or lightheadedness. It was also defined as unstable and having a new onset or sudden worsening of angina, manifested by one or more episodes of typical symptoms, as attacks lasting longer than 15 minutes or as attacks which occur during rest or minimal activity.
Congestive heart failure was classified as having paroxysmal nocturnal dyspnea, dyspnea at rest, or NYHA II orthopnea, plus one of the following: moist basilar rales, 2+ or greater pretibial edema, tachycardia >119 beats/minute after 5 minutes at rest, cardiomegaly, interstitial edema by chest x-ray, S3 (ventricular) gallop, or jugular venous distention in the absence of C.O.P.D., pneumonia or other documented lung disease. Atrial fibrillation was defined as a dysrhythmia manifested by an irregular ventricular rate, absent atrial contraction and fibrillating atrial waves on EKG.
Valvular heart disease was defined as having an alteration of cardiovascular function as a result of rheumatic heart disease, congenital lesions or a number of miscellaneous acquired types of valvular heart diseases with significant stenosis and/or regurgitation of the valve. Leg claudication was characterized by pain or cramps involving the limb musculature, often precipitated by exertion and relieved by rest.
Cardiac surgery was characterized as an operation performed on the heart, including angioplasty (stenting), coronary artery bypass graft or valvular surgery. Carotid endarterectomy was defined as a reconstructive vascular operation aimed at removing a stenotic or ulcerative plaque involving the origin of the internal carotid artery. Peripheral arterial vascular surgery was defined as reconstructive surgery or angioplasty of major peripheral arteries. Reconstructive surgery of the thoracic or abdominal aorta defined thoracic or abdominal aortic surgery.
A history of exercise was defined as leisure-time exercise at least two times per week during the past year and sufficient to work up a sweat. Patients were asked to identify whether there was a family history of stroke among family members, subject’s parents, siblings or grandparents. Cigarette smoking was classified as “never” if the patient had smoked any number of cigarettes per day for <1 year or had never smoked cigarettes; as “former smoker” if the patient smoked any number of cigarettes per day for >1 year but had not smoked in the past 12 months; and as “current smoker” if the patient smoked for >1 year any number of cigarettes per day and had smoked in the past 12 months. Alcohol use was defined as “none or occasional” consumption if the patient characterized his/her alcohol consumption as none or occasional; as “regular or daily” if alcohol consumption occurred with a regular or daily use; or as “heavy” if the patient admitted to regular or daily drinking and characterized himself or herself as a heavy user of alcohol. canadian antibiotics
Patients also were asked to give history regarding previous strokes or transient ischemic attack (TIA). These were ascertained by asking patients if their doctors had told them they had suffered an ischemic stroke, brain hemorrhage or TIA.