Aging pot smokers up heart attack risk - study

SAN DIEGO, March 2 (Reuters) - Smoking marijuana significantly increases the risk of a heart attack for middle-aged and elderly users during the first hour after using the drug, researchers reported Thursday. The heart attack risk was 4.8 times higher during the first hour following marijuana use than it was during times of non-use, according to a study by researchers in Boston. In the second hour, the risk dropped to 1.7 times higher than normal. Dr. Murray Mittleman, director of cardiovascular epidemiology at Beth Israel-Deaconess Medical Center, said he believed the study was the first to show a link between pot smoking and heart attacks. He said the findings should be a warning to baby boomers who picked up the habit when they were younger and still smoke marijuana. "They should at least be aware that their risk of a heart attack suddenly soars each time they smoke the drug," Mittleman said. The findings showed "the short-term risk is considerable" for marijuana users, especially those with other qualities that put them at risk for heart attacks, Mittleman said. The researchers said they were not sure whether the marijuana itself or other components of smoke such as carbon monoxide were responsible for the higher heart attack risk. Smoking marijuana can boost heart rates by about 40 beats per minute, Mittleman said. It also causes blood pressure to increase when the smoker is lying down and abruptly fall when they stand up, often causing dizziness, he added. "These effects may pose significant risk, especially in people with unrecognized coronary disease," Mittleman said. Other studies have shown that younger marijuana smokers are not at a greater risk for heart attacks. Mittleman's research team collected information from 3,882 people who had heart attacks. Of that group, 124 were identified as current marijuana users, including 37 who said they smoked the drug within 24 hours before their heart attack and nine who reported smoking pot within an hour of their first symptoms. The average age of the marijuana users was 46, Mittleman said. The study results were being presented at an American Heart Association (AHA) conference in San Diego. The research was funded by the National Heart, Lung and Blood Institute and the AHA.