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Effect of smoking on the activity of ischemic heart disease
1Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115.
Insights
Cigarette smoking significantly worsens ischemic heart disease activity. Smokers experienced three times more frequent and 12 times longer episodes of myocardial ischemia compared to non-smokers.
Area of Science:
- Cardiology
- Cardiovascular Disease
- Preventive Medicine
Background:
- Cigarette smoking is a known cause of coronary heart disease (CHD).
- The impact of smoking on the daily activity of ischemic heart disease requires further investigation.
Purpose of the Study:
- To quantify the effect of smoking on the frequency and duration of myocardial ischemia in patients with coronary artery disease.
Main Methods:
- Continuous ambulatory monitoring was used to assess ST segment depression in 65 patients with stable coronary artery disease.
- Twenty-four smokers were compared with 41 non-smokers over a 24-hour period.
- Logistic regression controlled for potential confounding factors.
Main Results:
- Smokers had a median of three times more frequent episodes of ischemia than non-smokers.
- The median duration of ischemia was 12 times longer in smokers (24 minutes/24 hours) compared to non-smokers (2 minutes/24 hours).
- These differences were statistically significant after controlling for confounding variables.
Conclusions:
- Patients with coronary artery disease who smoke exhibit substantially more active myocardial ischemia during daily life.
- Smoking cessation is crucial for managing ischemic heart disease activity.
- This study highlights the detrimental effect of smoking on daily ischemic burden in CHD patients.
Abstract:
Cigarette smoking has been causally linked to coronary heart disease. To investigate the effect of smoking on the activity of ischemic heart disease, 65 patients with chronic stable manifestations of coronary disease and a positive exercise tolerance test underwent continuous ambulatory monitoring to quantify the amount of ischemic ST segment depression during daily life. Twenty-four smokers were compared with 41 nonsmokers for frequency and duration of electrocardiographic signs of ischemia during 24 hours. A total of 4,968 hours of ambulatory monitoring were analyzed. The frequency of episodes was three times as often (median) and the duration of ischemia was 12 times longer (median duration, 24 vs 2 min/24 h) in smokers than nonsmokers. This finding remained statistically significant when a number of potentially confounding factors were controlled by means of logistic regression. This study shows that patients with coronary artery disease who smoke have significantly and substantially more active myocardial ischemia during daily life than patients who do not.