Differential effects of heat-not-burn and conventional cigarettes on coronary flow, myocardial and vascular function

Figure 1. Acute effects of heat-not-burn puffing versus tobacco cigarette smoking. Comparison between the acute effects of heat-not-burn versus tobacco cigarette smoking on (A) arterial stiffness, (B) oxidative stress burden, and (C) platelet activation status. HBNC showed a smaller increase of PWV than tobacco cigarette. All biomarkers are impaired following Tcig smoking, in contrast with HNBC puffing. PWV carotid-femoral pulse wave velocity, HNBC heat-not-burn cigarette, MDA malondialdehyde, Tcig tobacco cigarette, TxB2 thromboxane B2, SE Standard Error.

Figure 2. Progression of coronary flow reserve, flow mediated dilation, and myocardial work within 1 month of follow-up. Replacement of Tcig smoking with HNBC puffing for 1-month results in coronary and peripheral endothelial function improvement, along with wasted myocardial work reduction. CFR coronary flow reserve, FMD flow-mediated dilation, GWW global wasted work, SE Standard Error.

Figure 3. Coronary flow of left anterior descending artery at rest (left panel) and after adenosine infusion (right panel) for calculation of coronary flow reserve. Coronary flow of left anterior descending artery at rest (left panel) and after adenosine infusion (right panel) for calculation of coronary flow reserve at baseline (A) and after switching to HNBC for one month (B). The coronary flow reserve increased from 2.5 to 3.1 after 1 month of switching from tobacco cigarette to HNBC.

Figure 4. Flow chart of the study population. HNBC heat-not-burn cigarette, TCig tobacco cigarette.

Figure 5. Acute phase protocol. Following an initial sham smoking session, subjects were randomised to either a heat-not-burn or traditional cigarette smoking session; following a washout period of 60 min, they were crossed-over to the alternative smoking session. Each session was followed by a vascular stiffness examination and blood-sampling for oxidative stress and platelet activation assessment. Exam examination, HNBC heat-not-burn cigarette, TCig tobacco cigarette.