Electronic Cigarettes: No Adverse Effects on Coronary Microcirculation

August 31, 2013 / Medscape / AMSTERDAM, THE NETHERLANDS — Authors of a small study looking at the microcirculatory effects of electronic cigarettes say their findings offer more early reassurances of safety for the newfangled devices, given that long-term studies on hard end points will be a long time coming[1].

“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.