Lifetime cumulative exposure to waterpipe smoking is associated with coronary artery disease

- 3 fold net increase in odds of severe CAD with lifetime use exceeding 40 WP-years.
- Associations showed a consistent dose-response relationship with increasing exposure.
- CAD Index score increased by 7.8 points with lifetime use exceeding 40 WP-years.
- There is a need to monitor and document WP use among cardiac patients.

ObjectiveGlobally, waterpipe (WP) smoking is becoming a more prevalent form of tobacco consumption. Whilst research so far has demonstrated a significant link between WP use and a number of health outcomes, little is known of its association with heart disease. We examine in this study the association of WP smoking with angiographically confirmed coronary artery disease (CAD).MethodsA total of 1210 patients, aged 40 years and over and free from smoking-associated illnesses or history of cardiovascular procedures, admitted for coronary angiography at four major hospitals in Lebanon, were included. The extent of CAD was summarized in two ways, firstly as diseased (≥50% and ≥70% occlusion in at least one main coronary artery) versus non-diseased (entirely normal coronaries), and secondly, as CAD cumulative score based on Duke CAD Prognostic Index. A score of WP-years, capturing intensity and lifetime duration of exposure, was estimated for each individual.ResultsLifetime exposure exceeding 40 WP-years was associated with a threefold significant increase in the odds of having severe stenosis (≥70%) compared to non-smokers (OR = 2.94, 95% CI 1.04-8.33) as well as with the CAD Index (β = 7.835, p-value = 0.027), net of the effect of socio-demographic characteristics, health behaviors and co-morbidity. A dose-response relationship between WP-years and percent stenosis was also established. WP smoking status (never, past and current) did not associate with CAD.ConclusionsCumulative exposure to WP smoking is significantly associated with severe CAD. There is a need to monitor WP use among cardiac patients and include this information in their medical charts in the same manner cigarettes smoking is documented. This is likely to increase awareness of the hazards of WP smoking and prompt physicians to target WP tobacco control by providing advice to their patients on WP smoking cessation.