Tobacco smoke causes endothelial dysfunction within minutes of inhalation. Over years, this cumulative damage accelerates atherosclerosis and raises blood pressure. The result is a dramatically elevated risk of myocardial infarction and stroke.
The good news is that cessation works fast. Within 20 minutes of quitting, blood pressure drops. Within a year, excess coronary heart disease risk halves. Within 15 years, the risk of heart attack approaches that of a lifelong non-smoker.