Abstract
OBJECTIVES: Recent studies have suggested a potential link between opium consumption and microvascular dysfunction in coronary arteries, which may contribute to the development of coronary slow-flow syndrome. This study aims to investigate the relationship between opium use and coronary slow-flow syndrome. DESIGN AND SETTING: This retrospective study analysed medical records of patients who underwent coronary angiography at the Tehran Heart Center from 2006 to 2020. It focused on those with coronary slow flow phenomenon (CSFP) or non-obstructive coronary artery disease, excluding patients with significant left ventricular dysfunction (left ventricular ejection fraction <40%), previous coronary revasculariation, arrhythmias or coronary artery ectasia. The coronary slow flow was assessed using thrombolysis in myocardial infarction flow grade and frame count. Propensity score matching and inverse probability weighting were applied to minimise confounding variables. Conditional logistic regression and logistic regression models were then used to examine the association between opium use and coronary slow flow, controlling for potential confounders. RESULTS: Among 21 835 patients with normal coronary angiograms, 767 were identified with CSFP and matched with 3068 controls. The mean age of CSFP patients was 51.59 years, with 64.6% male. Opium use was similar, reported in 8.9% of CSFP patients and 9.5% of controls (p=0.96). Within the CSFP group, opium use was associated with more extensive coronary artery involvement (33.3% vs 18.9%, p=0.03). Initial analysis indicated a higher risk for CSFP in opium users (OR: 1.74, p=0.001), but after adjustments, no significant association was found (OR: 1.06, p=0.70; OR: 1.15, p=0.55). CONCLUSION: Our study indicates that opium use is not an independent risk factor for CSFP but may exacerbate the severity of coronary artery involvement, noted by a higher incidence of multivessel disease among users. This suggests that opium may affect the extent of coronary artery issues rather than cause CSFP directly.