Secondhand tobacco smoke exposure a risk factor for coronary atherosclerosis

NEW ORLEANS — A new study presented at the American Heart Association Scientific Sessions strengthens the association between the extent of coronary atherosclerosis and the level of secondhand smoke exposure.

Researchers issued a questionnaire to 268 never-smokers aged 40 to 80 years to assess risk factors and extent of lifetime secondhand tobacco smoke exposure, providing a total secondhand tobacco smoke score.

To determine ordinal coronary artery calcium scores, low-dose non-gated CT scans were used, followed by CT angiography.

Harvey Hecht, MD, from the division of cardiology at Icahn School of Medicine at Mount Sinai, presented the findings, which were simultaneously published in JACC: Cardiovascular Imaging.

“The extent and importance of secondhand tobacco smoke [exposure] as a major global health issue cannot be overestimated,” Hecht and colleagues wrote in JACC: Cardiovascular Imaging. “Increasing awareness of the heavy toll exacted by secondhand tobacco smoke exposure, particularly [CV], has resulted in more intensive investigation of the accompanying atherosclerosis, particularly that detectable in early stages by noninvasive modalities.”

Hecht and colleagues analyzed the prevalence, extent and plaque characteristics of atherosclerosis to determine the independent contribution of secondhand tobacco smoke exposure after adjustment for known risk factors.

Coronary atherosclerosis was observed in 48% of patients, and was more prevalent in those with low to moderate secondhand tobacco smoke exposure (48%) and high exposure (69%) compared with minimal exposure (25%; P < .0001).

Compared minimal secondhand tobacco smoke exposure, the odds of developing atherosclerosis were higher among those with low to moderate exposure (OR = 2.1; 95% CI, 1-4.4) and high exposure (OR = 3.5; 95% CI, 1.4-8.5). The researchers did not find a significant relationship between atherosclerosis and diabetes (P = .56), hyperlipidemia (P = .11), hypertension (P = .65) or renal disease (P = .24).

As exposure to secondhand tobacco smoke exposure increased, any plaque or stenosis in a major vessel was more prevalent (minimal exposure, 14%; low to moderate exposure, 41%; high exposure, 45%; P = .0013) as were the odds of five or more involved segments (minimal exposure, 0%; low to moderate exposure, 39%; high exposure, 61%; P = .0001), Hecht and colleagues reported. The researchers noted that the effect of secondhand tobacco smoke exposure was more pronounced in those with calcification or partial calcification compared with no calcification.

“Although the study sample size is modest; the initial insights are astounding,” Khurram Nasir, MD, MPH, from Baptist Health South Florida, Florida International University and the Johns Hopkins Ciccarone Center for the Prevention of Heart Disease, and Jaideep Patel, MD, from the Johns Hopkins Ciccarone Center for the Prevention of Heart Disease and Virginia Commonwealth University Medical Center, Richmond, wrote in a related editorial published in JACC: Cardiovascular Imaging. “The results of this study demonstrated a powerful graded linear relationship between the severity of secondhand tobacco smoke exposure and the presence and severity of coronary artery plaque that overcomes any lingering doubt about the deleterious impact of secondhand tobacco smoke.”

According to Nasir and Patel, the results of this trial provide an opportunity to publicly discuss the potentially fatal coronary effects of secondhand tobacco smoke exposure, provide policy makers with evidence to work toward implementing smoke-free laws, promote discussion amongst stakeholders to incorporate universal secondhand tobacco smoke exposure screenings in primary care practice, and can provide incentive to assess the link between atherosclerotic disease and secondhand smoke in population-based studies. – by Dave Quaile

Reference:

Hecht H, et al. Abstract S2106. Presented at: American Heart Association Scientific Sessions; Nov. 12-16, 2016; New Orleans.

Nasir K, Patel J. JACC Cardiovasc Img. 2016;doi:10.1016/j.jcmg.2016.09.004.

Yankelevitz DF, et al. JACC Cardiovasc Img. 2016;doi:10.1016/j.jcmg.2016.07.003.

Disclosures: Hecht reports consulting for Philips Medical Systems. Nasir reports serving on an advisory board for Quest Diagnostics and consulting for Regeneron. Patel reports no relevant financial disclosures.