No adverse effects on coronary microcirculation electronic cigarettes

Dr Konstantinos Farsalinos


"This study adds to currently available evidence that supports that electronic cigarettes are significantly less harmful compared with tobacco," Dr Konstantinos Farsalinos(Onassis Cardiac Surgery Center, Kallithea, Greece) said here at the European Society of Cardiology (ESC) 2013 Congress. "Monitoring of consumers for several years will determine the long-term effects of electronic cigarette use."

At last year's ESC meeting, Farsalinos presented the results of a small study comparing effects on left ventricular function, blood pressure, and heart rate in 40 subjects, as reported by heartwire.

At this year's meeting, Farsalinos presented an analysis, this time in 60 subjects, looking at coronary flow velocity reserve (CFVR) and coronary vascular resistance index (CVRI). Thirty subjects were current smokers; in this group, CFVR/CVRI was measured in response to adenosine administration, 20 to 30 minutes after smoking two cigarettes and after using an electronic cigarette. Another 30 patients, made up of patients who had had their last cigarette at least one month previously, underwent the same tests, 20 to 30 minutes after using an electronic cigarette. Nonuse of cigarettes in this group was confirmed via testing of carboxyhemoglobin levels.

As Farsalinos showed here, no differences in CFVR and CVRI were seen following e-cigarette use, both in the nonsmoking group and in the group of smokers who were also studied after trying the e-cigarette. By contrast, smokers saw a 16% decrease in CFVR (p<0.001) and a 19% decrease in CVRI (p<0.001) 20 to 30 minutes after smoking their two cigarettes.


Harm reduction?
"The electronic cigarette is not a product that is recommended for everyone as a new habit, it is recommended for smokers as an alternative to smoking to reduce consumption or to quit," Farsalinos said. "It is not for the general population; that should be clear."

Farsalinos acknowledged that the devices do emit low levels of harmful substances in addition to nicotine. "Both formaldehyde and acrolein have been found," he said. "They are produced in the heating and evaporation process, so they are not present in the liquid, but in the vapor. But the levels in electronic cigarettes are from 10 to 400 times lower compared with tobacco. The same was observed with nitrosamines, which are approximately 500 to 1000 times lower compared with tobacco cigarettes.

"The presence of such chemicals are found in very low levels; so we have to see for a long period of years if there are complications. But we can say [with confidence] that they are by orders of magnitude lower, and most likely it would be beneficial for smokers to switch to electronic cigarettes if they cannot quit by other methods."


Wait and see