Smokers more likely to die from heart disease than lung cancer

• Link to: Northwestern Now Story

CHICAGO --- The most likely cause of death for people who smoke is a fatal heart attack, stroke or heart failure that occurs without any warning signs, reports a new Northwestern Medicine study. 

“Most people are aware about the risks of lung cancer with smoking, but many people who smoke do not realize that dying from cardiovascular disease is more likely than dying from lung cancer,” said lead study author Dr. Sadiya Khan, an assistant professor of medicine at Northwestern University Feinberg School of Medicine and a Northwestern Medicine cardiologist. 

This is the first study showing smokers are more likely to die from cardiovascular disease than lung cancer and to show they are more likely to die from a fatal cardiovascular event without warning.

“This is so important because in the U.S., one in five people still report using tobacco, which may have increased with the added stress of the pandemic,” Khan said.

The analysis was an observational study and used individual-level data from multiple cohorts that followed people for several decades to examine risk of cardiovascular disease based on whether someone smoked or not. 

“One of the most important findings of this analysis is that the first sign of cardiovascular disease is more likely to be a fatal event in those who smoke,” Khan said. “Smoking is more likely to kill people from heart disease even before someone may know they have heart disease.”

The paper will be published Nov. 17, 2021, in the Journal of the American Heart Association.

Key study findings:

• More than 50% of adults aged 40 to 59 who smoked developed cardiovascular disease and were 1.8 times more likely to die of a fatal heart attack, stroke or heart failure without previous warning.
• Young men and women who smoked were more than twice as likely to have a fatal cardiovascular event as their first sign of cardiovascular disease as those who didn’t smoke.
• Smoking was linked to developing cardiovascular disease at a younger age and shortening a person’s lifespan by as much as four to five years. 

“This is especially relevant from a public health perspective as our study examined young adults beginning at age 20 years and included decades of follow-up,” said senior author Dr. Ranya Sweis, an associate professor of medicine in cardiology at Northwestern. “Our findings show putting an emphasis on smoking cessation counseling is the most important preventable cause of death in the United States.” 

The researchers pooled data from nine previous studies in the U.S. to evaluate the risk of smoking and cardiovascular disease. The analysis included data for 106,165 adults between the ages of 20 and 79 who were free from cardiovascular disease at the start of the studies. 

Decades of research links cigarette smoking to early death caused by cardiovascular disease and other diseases such as lung cancer. According to the American Heart Association’s Heart and Stroke Statistical Update 2021, more than 480,000 U.S. adults die each year from smoking-related cardiovascular disease. More than 34 million adults in the U.S. still smoke cigarettes. Risks of smoking extend to those who may be exposed to secondhand smoke as well. 

Northwestern co-authors are Dr. Hongyan Ning, Dr. Arjun Sinha, Dr. John Wilkins, Norrina Allen, Dr. Thanh Huyen Vu and Dr. Donald Lloyd-Jones.

The study was funded by the National Institutes of Health's National Heart, Lung, and Blood Institute and National Center for Advancing Translational Sciences grants R21 HL085375 KL2TR001424, and the American Heart Association.