Objectives: To determine sex/gender differences in the distribution of risk factors according to age and identify factors associated with the presence of severe coronary artery disease (CAD).
Design: We analysed 23,771 consecutive patients referred for coronary angiography from 2000 to 2006.
Subjects: Patients did not have previously diagnosed CAD and were referred for first diagnostic angiography.
Outcome measures: Patients were classified according to angiographic disease severity. Severe CAD was defined as left main stenosis > or = 50%, three-vessel disease with > or = 70% stenosis or two-vessel disease including proximal left anterior descending stenosis of > or = 70%. Univariate and multivariate logistic regression was used to assess the association between risk factors and angina symptoms with severe CAD.
Results: Women were less likely to have severe CAD (22.3% vs. 36.5%) compared with men. Women were also significantly older (69.8 +/- 10.6 vs. 66.3 +/- 10.7 years), had higher rates of diabetes (35.0% vs. 26.6%), hypertension (74.8% vs. 63.3%) and Canadian Cardiovascular Society (CCS) class IV angina symptoms (56.7% vs. 47.8%). Men were more likely to be smokers (56.9% vs. 37.9%). Factors independently associated with severe CAD included age (OR = 1.05; 95% CI 1.05-1.05, P < 0.01), male sex (OR = 2.43; CI 2.26-2.62, P < 0.01), diabetes (OR = 2.00; CI 1.86-2.18, P < 0.01), hyperlipidaemia (OR = 1.50; CI 1.39-1.61, P < 0.01), smoking (OR = 1.10; CI 1.03-1.18, P = 0.06) and CCS class IV symptoms (OR = 1.43; CI 1.34-1.53, P < 0.01). CCS Class IV angina was a stronger predictor of severe CAD amongst women compared with men (women OR = 1.82; CI 1.61-2.04 vs. men OR = 1.28; CI 1.18-1.39, P < 0.01).
Conclusions: Women referred for first diagnostic angiography have lower rates of severe CAD compared with men across all ages. Whilst conventional risk factors, age, sex, diabetes, smoking and hyperlipidaemia are primary determinants of CAD amongst women and men, CCS Class IV angina is more likely to be associated with severe CAD in women than men.