Year: 2012
Type: dissertation
Study design: Observational Study
Abstract: Exercise testing is a widely accepted diagnostic testing method.Previous studies have shown that physical fitness is one of the strongest risk factor for cardiovascular diseases (CVDs).Systolic blood pressure (SBP) during exercise test is an important hemodynamic variable.However, the prognostic value of systolic blood pressure during and after exercise test is not known with respect to stroke.Both exerciseinduced painful and painless ischemia have been previously documented as risk predictors for ischemic cardiac events.But little is known about silient ischemia during exercise test and the risk of stroke.Systolic blood pressure, exercise-induced myocardial ischemia and cardiorespiratory fitness were assessed using a maximal, symptom-limited exercise test on an electrically braked cycle ergometer.Respiratorygas exchange was measured for the 2361 men in a population based sample of men.During the follow-up, the classification of stroke events was carried out according to the multinational MONICA project.Men with SBP rise >19.7 mm Hg per minute of exercise duration had a 2.3-fold increased risk of any stroke and a 2.3-fold increased risk of ischemic stroke compared with men whose SBP rise was <16.1 mm Hg/min.Similarly, percentmaximum SBP at 2 minutes after exercise (SBP at 2 minutes' recovery divided by maximum SBP) was associated (highest tertile) with a 4.6-fold increased risk of any stroke and a 5.2-fold increased risk of ischemic stroke.The relative risk for any stroke in unfit men (VO2max, <25.2 mL/kg per minute) was 3.2 (95% CI, 1.71-6.12);and for ischemic stroke, 3.50 (95% CI, 1.66-7.41),compared with fit men (VO2max, >35.3 mL/kg per minute), after adjusting for age and examination year.Thirdly, men with silent ischemia during exercise had a 2.2-fold increased risk of stroke compared with men without silent ischemia, after adjusting for conventional risk factors.Silent ischemia during exercise was associated with a 3.8-fold (95% CI, 1.1 to 12.5) increased risk for stroke in smokers, a 3.5-fold (95% CI, 1.7 to 7.4) increased risk in hypercholesterolemic subjects, a 3.4-fold (95% CI, 1.6 to 7.1) increased risk in the hypertensives, and 2.9-fold (95% CI, 1.4 to 6.1) increased risk in overweight men.Men with low exercise cardiac power (<10.3mL/mm Hg) had 2.7-fold (95% CI, 1.2 to 6.0; P=0.01), risk for stroke and 2.7-fold (95% CI, 1.1 to 7.0; P=0.03) risk for ischemic stroke compared with men having high exercise cardiac power during exercise after adjusting for conventional risk factors.Cardiorespiratory fitness provides additional valuable prognostic information with the presence of other risk factors, and can be considered to be at least as important a risk factor as smoking, dyslipidemia, VI hypertension, type II diabetes and obesity.Silent myocardial ischemia during exercise testing predicts not only acute coronary events but also stroke in men with various risk factors.The clinical implication of this study is that painless myocardial ischemia is of strong prognostic value in the presence of conventional risk factors in men free of CHD, thereby stressing the importance of identifying high risk persons with exercise testing who are in the need of preventive measures.Systolic blood pressure responses during an exercise test can be used for identifying individuals at an increased risk for stroke.
Author: Sudhir Kurl
Language: English
Subfield: Physiology (medical)
Field: Medicine
Domain: Health Sciences
Open Access status: green
Funder: Itä-Suomen Yliopisto
OpenAlex ID: W3096432680