Secondhand Smoke Risk to Cardiac Patients Underappreciated

Marlene Busko

November 11, 2014

BOSTON, MA — In a single-center study, only 17% of hospitalized nonsmokers with coronary heart disease (CHD) were asked about exposure to tobacco smoke, and only 1.4% remembered receiving any advice about this modifiable risk factor, reported researchers[1]. Thus, the study suggests, clinicians are missing an important teachable moment.

"Once cardiologists ask about smoking status and hear that a patient is a nonsmoker, they generally feel that their job is done," Dr Nancy A Rigotti (Massachusetts General Hospital, Boston), senior author of a research letter published online November 10, 2014 in JAMA Internal Medicine, told heartwire . "However, their nonsmoking patients can be at increased risk of acute events because of secondhand-smoke exposure. Patients don't know that secondhand smoke is bad for the heart, and if doctors [and nurses] don't ask, they will not learn [about this risk]."

In this study, a sensitive blood test detected cotinine, a biomarker of tobacco exposure, in 40.3% of the hospitalized patients with CHD, but only about half of the patients believed that exposure to cigarette smoke was increasing their risk of having a heart attack.

Both inpatients and outpatients with cardiac disease need to be aware of the risk. "The findings of this study make a strong case for the need to address secondhand-smoke exposure more effectively in inpatient cardiology practice, [and] it is likely that secondhand-smoke exposure is similarly overlooked in outpatient cardiology practice," Rigotti and colleagues write.

Are Nonsmokers Wary of Tobacco Smoke?

Exposure to second-hand smoke increases risk of CHD by 30%, and Massachusetts, like many other states, implemented a nonsmoking ban in restaurants, bars, and workplaces in 2004, Rigotti noted.

However, little is known about the number of cardiac patients who are exposed to secondhand smoke from cigarettes or whether they are aware of the associated heart-health risks.

The study identified 214 nonsmokers admitted to a cardiac unit at a major hospital with a diagnosis of CHD between May 2010 and January 2011.

The patients had a bedside interview asking about secondhand-smoke exposure, and they provided a saliva sample for a high-performance liquid chromatography/tandem mass spectrometry cotinine test.

A number of patients reported that in the past month, they had been exposed to secondhand tobacco smoke at home (13%), in the car (16%), at work (7%), or all three places (22%). Secondhand tobacco smoke exposure was reported by 22.0% in the month before admission and by 15.4% in the week before admission. However, using a sensitive assay with a detection limit of 0.05 ng/mL, cotinine was detected in 40.3% of patients—suggesting that many patients were not aware of their exposure to tobacco smoke.

For the 13.6% of patients who lived with one or more smokers, it was more often an adult child who smoked (7%), followed by a spouse (5.6%) or other adult (3.3%).

Only 37% of patients recalled that a physician or nurse had asked them about secondhand-smoke exposure while they were on the cardiology ward.

Almost all knew that secondhand smoke was harmful to health (89%), but only 56% believed it could increase the risk of heart attack or believed that it could increase their own risk for a heart attack.

Implementing Change to Up Awareness

In an accompanying invited commentary[2], Dr R William Vandivier (University of Colorado, Aurora) writes that this study is important because it "clearly demonstrates where the healthcare community has failed to translate research into action." He suggests that having a prompt in electronic patient records might encourage clinicians to inform patients about this risk.

"Regardless of the method used to stimulate counseling by healthcare providers, the present study emphasizes the need to allocate energy and resources to uncover the effects of secondhand-smoke exposure and learn how to maximally implement these findings in patients to improve their health," he concludes.

Rigotti said that a simple intervention can up awareness. They recently published a study about their experience in the October 2014 issue of the American Journal of Cardiology[3]. Starting in October 2011, nurses asked newly admitted patients if anyone smoked in their home or car. They also read a statement to patients "In order to keep your heart heathy, you need to keep your home and car smoke free" and gave them a simple "smoke-free home" pamphlet to take home.

After this three-part intervention was put in place, patients were twice as likely to be aware that secondhand smoking increased their risk of a heart attack, compared with similar patients admitted earlier.

Rigotti has been an unpaid consultant for Pfizer and received travel expenses for a consultant meeting, has been an unpaid consultant to AlereWellbeing, and receives royalties from UpToDate. Disclosures for the coauthors are listed in the article. Vandivier reported he had no relevant financial relationships.


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