Highlights from

AHA 2020

American Heart Association’s Scientific Sessions

Virtual 13 - 17 November 2020

Children exposed to tobacco smoke have worse heart function as adults

Childhood passive smoke exposure, independent of whether the individual smokes themselves, was associated with a reduction in global longitudinal strain (GLS), a measure of subclinical cardiac dysfunction. The more passive smoke exposure a child had, the higher the risk for reduced heart function.

Dr Chigozie Ezegbe (University of Tasmania, Australia) presented the data, collected from 1,110 participants with outcome measures included in the Childhood Determinants of Adult Health study 34-year follow-up (2014-2019) [1]. Although it is generally believed that prolonged childhood exposure to passive smoke may affect adult cardiovascular health, there are few studies of cardiac function decades after the exposure. Subclinical left ventricular dysfunction detected by GLS is predictive of the subsequent development of heart failure and was used as a surrogate for increased risk. The investigators addressed the association of passive smoke exposure during childhood with GLS in adults.

The researchers derived the data retrospectively from a validated questionnaire, scoring 3 measures of passive smoke exposure: the severity of exposure index, the cumulative years of exposure, and the total number of household smokers. GLS was measured in clinics using a Siemens Acuson SC2000 ultrasound machine and 4V1c transducer with speckle tracking analysis. Linear regression adjusted for confounding factors (i.e. age, gender, childhood socioeconomic position, childhood smoking, adult smoking status, parental education level).

The mean age of the participants was 45.2 ± 2.5 SD years, and 55.4% were female. Of all participants, 54.2% had been exposed to passive smoking. Per standard deviation (SD) of severity of exposure index, the GLS decreased (range 0-318; mean 24.2 ± 35.8 SD; βadjusted -0.17%; 95% CI -0.32 to -0.02). Likewise, the cumulative years of exposure (range 0-106, mean 10.4 ± 13.9 SD) was associated with a decrease in GLS (βadjusted -0.18%; 95% CI -0.33 to -0.05) per SD of exposure. For each household smoker (range 0-5, mean 0.9 ± 1.0 SD), the GLS decreased as well (βadjusted -0.20%; 95% CI -0.36 to -0.05). Each 1% decrease in GLS has been associated with 12% higher risk of cardiovascular morbidity in mortality in low-risk general population. Every effort should be made to prevent exposure of children to passive smoking during childhood due to potential long-term consequences to cardiac function.

  1. Ezegbe C, et al. Childhood Passive Smoke Exposure is Associated With Subclinical Left Ventricular Dysfunction in Adulthood - Childhood Determinants of Adult Health Study. P1917, Virtual AHA Scientific Sessions 2020, 13-17 Nov.

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