Methods: This study was a retrospective analysis of patients who underwent diagnostic coronary angiography at Tehran Heart Center between April 2021 and May 2022. Patients with a previous history of percutaneous coronary intervention and coronary surgery were excluded. Waterpipe smokers were matched with non-smokers based on age, gender, and cigarette smoking using a 1:4 propensity score matching model. Stenosis ≥ 50% in any coronary artery was considered a CAD diagnosis. Gensini score was also calculated to measure the severity of the CAD.

Results: We reviewed the medical records of 8699 patients, including 380 waterpipe smokers. After matching, 1520 non-smokers with similar propensity scores to the waterpipe smokers were selected. Waterpipe smokers were more likely to have CAD than non-smokers (OR: 1.29; 95% CI: 1.04-1.60, P = 0.021). In addition, WPS increased the natural logarithm of the Gensini score by 1.24 (95% CI: 1.04-1.48, P = 0.014) in patients with atherosclerotic coronary disease.

Conclusion: WPS may increase the risk of CAD independent of age, gender, and cigarette smoking. In addition, among patients with any degree of atherosclerosis in coronary arteries (GS > 0), WPS may lead to higher average GS, suggesting more severe atherosclerosis.