P4421Effect of electronic cigarette smoking on pulse pressure amplification

Abstract

Background: Aim of the study was to investigate the acute effect of electronic cigarette (EC) smoking on the aortic pressure waveform amplification by measuring the aortic pressures and augmentation index (AIx) in young healthy smokers. We also sought to compare the effect of EC and combustible cigarette (TC) smoking on central haemodynamics. Methods: We studied 24 smokers (age: 30±8 years) otherwise free of cardiovascular risk factors on three separate occasions: a) tobacco cigarette (nicotine content, 1.2 mg) over 5 minutes, b) EC (18 mg E-liquid) for a period of 30 minutes, and c) nothing (sham procedure) for 60 minutes. Smoking EC for 30 min (15 puffs) was choosen to mimic the common pattern of EC smoking (nicotine delivered obtain plasma levels comparable to those after 5 minutes of TC smoking). Young subjects were chosen to minimize the compounding influence of age and disease states. The aortic pressures and AIx were measured by applanation tonometry (Sphygmocor). Results: Both TC and EC smoking caused a significant increase in brachial systolic, diastolic, pulse pressure and heart rate (HR), and the differences in blood pressure (BP) and HR responses between the two smoking forms were not significant. The aortic systolic, diastolic and pulse pressure also increased significantly after smoking both TC and EC, with the greatest changes seen in the first 5 minutes after TC smoking and 15 minutes EC smoking (figures 1A-C, all P<0.05). Athough AIx, which is heart rate-dependent, decreased in both two smoking forms, by applying a correction factor for changes in HR, the AIx increased significantly after TC (by 3.0% at 5 minutes, P<0.05) and EC (by 2.9% at 15 minutes, P<0.05) (figure 1D). Conclusions: Electronic cigarette smoking exerts an unfavorable and comparable to that of TC smoking acute effect on aortic pressure waveform amplification. Given the prognostic role of central haemodynamics on cardiovascular disease risk, EC may still be considered a hazardous smoking method. (Figure Presented).