. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Acute vs. chronic effects of e-cigarettes on vascular function Konstantinos E. Farsalinos 1,2,3 * 1 Department of Cardiology, Onassis Cardiac Surgery Center, Sygrou 356, Kallithea 17674, Greece; 2 Center of Excellence in Trauma and Accidents, King Abdulaziz University, Al Ehtifalat St, Jeddah 21589, Saudi Arabia; and 3 Department of Public and Administrative Health, National School of Public Health, L. Alexandras 196, Athens 11521, Greece Online publish-ahead-of-print 20 February 2020 This commentary refers to ‘Short-term e-cigarette vapour exposure causes vascular oxidative stress and dysfunction: evidence for a close connection to brain damage and a key role of the phagocytic NADPH oxidase (NOX-2)’, by M. Kuntic et al., doi: 10.1093/eurheartj/ehz772. I read with particular interest the study by Kuntic et al. who reported the acute adverse effects of e-cigarette use on endothelial function and arterial stiffness. 1 The authors concluded that e-cigarettes have the potential to induce marked adverse cardiovascular, pulmonary, and cerebrovascular consequences. However, I am concerned that their findings have questionable clinical relevance for long-term car- diovascular risk. While endothelial function and arterial stiffness are prognostic markers, this is applicable only when measured under strict resting conditions and when refraining from stimulant intake for several hours, as recommended in published guidelines. 2 There is no evi- dence that changes in vascular function after an acute intervention have any prognostic value. Acute adverse effects on vascular func- tion have been observed immediately after intake of caffeine and approved nicotine replacement therapies (NRTs), 3,4 both of which are not considered risk factors for cardiovascular disease. In fact, quitting smoking with NRTs results in rapid improvement in vascu- lar function when measurements were performed according to guidelines. Very recently, a study identified rapid (within 4 weeks) improvement in vascular function (measured at rest) when switch- ing from smoking to e-cigarette use. 5 Remarkably, no difference was observed between nicotine-containing and nicotine-free e-ciga- rettes, while improvement was observed even in those smokers who did not completely quit smoking but reduced their cigarette consumption. The study did not compare e-cigarettes with pharmacological smoking cessation products or with quitting with- out any aid; however, it suggests that at least for smokers unable or unwilling to quit by themselves or with current approved meth- ods, e-cigarettes may reduce the future risk for cardiovascular dis- ease when used as smoking substitutes. This is contradictory to the interpretation of the acute effects of e-cigarette as presented by Kuntic et al. In conclusion, while more research is certainly needed to identify the long-term effects of switching from smoking to e-cigarette use on the cardiovascular system, the acute effects of delivering a stimulant (nicotine) on vascular function cannot be used as a prognostic marker for cardiovascular risk. Therefore, the findings by Kuntic et al. have questionable clinical value on future disease risk and should be inter- preted with caution. Conflict of interest: none declared. References 1. Kuntic M, Oelze M, Steven S, Kro¨ ller-Scho¨n S, Stamm P, Kalinovic S, Frenis K, Vujacic-Mirski K, Bayo Jimenez MT, Kvandova M, Filippou K, Al Zuabi A, Bru¨ckl V, Hahad O, Daub S, Varveri F, Gori T, Huesmann R, Hoffmann T, Schmidt FP, Keaney JF, Daiber A, Mu¨nzel T. Short-term e-cigarette vapour exposure causes vascular oxidative stress and dysfunction: evidence for a close connection to brain damage and a key role of the phagocytic NADPH oxidase (NOX-2). Eur Heart J 2019; doi: 10.1093/eurheartj/ehz772. 2. Laurent S, Cockcroft J, Van Bortel L, Boutouyrie P, Giannattasio C, Hayoz D, Pannier B, Vlachopoulos C, Wilkinson I, Struijker-Boudier H; European Network for Non-invasive Investigation of Large Arteries. Expert consensus document on arterial stiffness: methodological issues and clinical applications. Eur Heart J 2006; 27:2588–2605. 3. Mahmud A, Feely J. Acute effect of caffeine on arterial stiffness and aortic pressure waveform. Hypertension 2001;38:227–231. 4. Adamopoulos D, Argacha JF, Gujic M, Preumont N, Degaute JP, van de Borne P. Acute effects of nicotine on arterial stiffness and wave reflection in healthy young non-smokers. Clin Exp Pharmacol Physiol 2009;36:784–789. 5. George J, Hussain M, Vadiveloo T, Ireland S, Hopkinson P, Struthers AD, Donnan PT, Khan F, Lang CC. Cardiovascular effects of switching from tobacco cigarettes to electronic cigarettes. J Am Coll Cardiol 2019;74:3112–3120. * Corresponding author. Tel: 00306977454837, Email: kfarsalinos@gmail.com Published on behalf of the European Society of Cardiology. All rights reserved. VC The Author(s) 2020. For permissions, please email: journals.permissions@oup.com. European Heart Journal (2020) 41, 1525 DISCUSSION FORUM doi:10.1093/eurheartj/ehaa073 Downloaded from https://academic.oup.com/eurheartj/article/41/15/1525/5741380 by guest on 21 October 2022