Predictive value and various patterns of abnormal ECG-gated MPI for Coronary Artery Disease (CAD) in Male Smokers

Abstract

Background: Cigarette smoking is generally considered as a powerful risk factor for coronary artery disease (CAD) and cardiac mortalities. Aim was to find out predictive value of smoking for extent of coronary artery disease (CAD) among males using ECG-gated myocardial perfusion imaging (GMPI).

Material and Methods: Total 5421 male patients were included and divided into smokers (n=1619; mean 12 ± 2 cigarettes/day) and non-smokers (n=3802). One day stress/rest GMPI protocol using Tc-99m MIBI was performed in all patients.

Results:  This prospective study was conducted from January 2010 till January 2014. Smokers were found to have higher incidence of abnormal GMPI at relatively lower effort tolerance. Incidence of reversible ischemia with transient ischemic dilatation (TID) was similar while fixed and mixed perfusion defects, predominantly larger sized defects with LV dysfunction was higher in smokers than non-smokers  (p<0.05). Using multivariate analysis, smoking was found to be an independent risk factor for CAD with synergistic effect with other risk factors like obesity, hypertension, diabetes, dyslipidemia and family history for CAD.

Conclusion: Smokers tend to have higher incidence of abnormal GMPI with larger size fixed and mixed perfusion defects and more severe LV dysfunction than non-smokers. No significant difference was noted for inducible ischemia and TID between two groups. Smoking is an independent risk factor for CAD having synergistic effects with other risk factors.

Key words:  Gated MPI; Cigarette smoking;  Fixed defect; predictive value