ScienceDaily (Feb. 14, 2008) — The proverbial cigarette after a Valentine’s Day snuggle can prematurely end a love affair, as new evidence emerges that a common defect in a gene significantly increases a smoker’s risk of an early heart attack. Researchers say that as much as 60 to 70 percent of the population has a gene defect that delivers a one-two punch to smokers: In a recent published study, heavy smokers with this common gene variant experienced a heart attack around the age of 52.