From the Journals

Atherosclerotic disease risk persists decades after smoking cessation

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Keep encouraging all smokers to quit

Although the pathophysiology of smoking and cardiovascular disease has yet to be teased out, the current study findings support the public health message that any and all smokers can improve their health by quitting any time: “It is never too early or too late to benefit from quitting,” wrote Nancy A. Rigotti, MD, and Mary M. McDermott, MD, in an accompanying editorial. The editorialists questioned whether the findings were generalizable to patients with mild PAD or those who are not hospitalized. However, they found the data consistent with previous studies suggesting that atherosclerosis is not homogeneous. “Differences in shear stress and hemodynamic forces among the femoral, coronary, and carotid arterial beds may also explain variability in associations of smoking and smoking cessation with the incidence of PAD versus myocardial infarction or stroke,” they said.

The findings also support the need to emphasize PAD in public health messages and provide an opportunity to educate patients about the risks of limb loss and impaired mobility associated with PAD, they said.

Many clinicians put a low priority on smoking cessation, the editorialists wrote, but “long-term tobacco abstinence is achievable using a chronic disease management approach resembling the strategies used to manage other risk factors,” they said. They cited the American College of Cardiology’s recently released “Expert Consensus Decision Pathway on Tobacco Cessation Treatment.” The pathway outlines advice for clinicians, including how to provide a brief intervention and resources along with advice to quit smoking.

Dr. Rigotti is affiliated with Harvard Medical School, Boston. Dr. McDermott is affiliated with Northwestern University, Chicago. Dr. Rigotti disclosed royalties from UpToDate, serving as a consultant for Achieve Life Sciences, and travel expenses from Pfizer for unpaid consulting. Dr. McDermott disclosed research funding from Regeneron, the National Heart, Lung, and Blood Institute, the National Institute on Aging, and the American Heart Association, plus research support from Chromadex, ReserveAge, Hershey, and ViroMed.


 

FROM THE JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY

Adults who quit smoking reduced their risk for peripheral artery disease in the short term, but remained at increased risk for up to 30 years, compared with never-smokers, based on data from more than 13,000 adults in a community-based study.

Illustration, charts: smoking, PAD. A significantly increased risk for PAD persisted for up to 30 years after smoking cessation among adults with no previous history of PAD. Courtesy Journal of the American College of Cardiology

Most reports on the impact of smoking cessation on cardiovascular disease have focused on coronary heart disease (CHD), and stroke, while data on the effects of smoking cessation on peripheral artery disease (PAD) are limited, wrote Ning Ding, MBBS, SCM, of the Johns Hopkins Bloomberg School of Public Health, Baltimore, Md., and colleagues.

To compare the impact of smoking on PAD, CHD, and stroke, the researchers used data from the Atherosclerosis Risk in Communities (ARIC) study, which included 15,792 adults aged 45-64 years in four communities. The findings were published in the Journal of the American College of Cardiology.

The study population of 13,355 individuals had no baseline history of PAD, CHD, or stroke. Over a median 26 years of follow-up, the researchers identified 492 cases of PAD, 1,798 cases of CHD, and 1,106 cases of stroke.

The risk of all three conditions began to decline within 5 years of smoking cessation, which could be encouraging to smokers who wish to quit, the researchers noted. In addition, the longer the duration of smoking cessation, the lower the risk for all three conditions (See central illustration).

However, a significantly elevated risk remained for PAD for up to 30 years after smoking cessation and for CHD for up to 20 years after smoking cessation, compared with never-smokers.

The researchers also found a roughly fourfold increased risk for PAD for smokers who smoked for 40 or more pack-years, compared with never-smokers, which was greater than the 2.1 hazard ratio for CHD and 1.8 HR for stroke. In addition, current smokers of at least one pack per day had a significantly greater risk of PAD, compared with never-smokers (HR, 5.36) that was higher than the risk for CHD or stroke (HR, 2.38 and HR, 1.88, respectively).

The study findings were limited by several factors including the reliance on self-reports, potential misclassification of data, and the potential exclusion of mild PAD cases that did not require hospitalization, the researchers noted. However, the results support the value of encouraging smokers to quit and support the need to include PAD risk in public health information, they said. “Although public statements about smoking and [cardiovascular disease] have been focusing on CHD and stroke, our results indicate the need to take account of PAD as well for comprehensively acknowledging the effect of smoking on overall cardiovascular health,” they added.

The ARIC study was funded by the National Heart, Lung, and Blood Institute, National Institutes of Health. Lead author Dr. Ding had no financial conflicts to disclose; coauthors disclosed relationships with Bristol-Myers Squibb and Fukuda Denshi.

SOURCE: Ding N et al. J Am Coll Cardiol. 2019 Jul 22;74:498-507. doi: 10.1016/j.jacc.2019.06.003.

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