Compositional plaque progression in women and men with non-obstructive coronary artery disease

Background: In coronary artery disease (CAD), plaque progression and plaque composition are associated with cardiovascular risk. Whether compositional plaque progression in non-obstructive CAD differs between women and men is less studied. Methods: We included 31 patients (42% women) with chronic non-obstructive CAD from the Norwegian Registry of Invasive Cardiology, undergoing serial coronary computed tomography angiography (CCTA) on clinical indication (median inter-scan interval 1.8 [1.5-2.2] years). We performed quantitative and qualitative plaque analysis of all coronary artery segments. Results: Women were older compared to men (65 +/- 8 years vs. 55 +/- 12 years, p = 0.019), while there was no difference in the prevalence of hypertension, diabetes, smoking or statin treatment between groups. At baseline, women had a higher total plaque burden, more calcified plaques, and less fibro-fatty and necrotic core plaques compared to men (all p < 0.05). During follow-up, men showed faster progression of fibro-fatty plaques (4.0 +/- 5.4 % per year vs. -0.6 +/- 3.1 % per year, p = 0.019) and a greater reduction of fibrous plaques (-7.3 +/- 6.1 % per year vs. 2.1 +/- 7.2 % per year, p = 0.003) compared to women even after age adjustment. At follow-up, total plaque burden remained higher in women compared to men (24.9 +/- 3.3 % vs. 21.1 +/- 2.6 %, p = 0.001), while men had an increase in fibro-fatty (21.2 +/- 9.3 % vs. 28.6 +/- 9.8 %, p = 0.004) and necrotic core plaques (5.6 +/- 3.6 % vs. 10.8 +/- 7.2 %, p = 0.006), and a decrease in fibrous plaques (69.0 +/- 11.9 % vs. 54.7 +/- 13.7 %, p < 0.001). Women's plaque composition remained unaltered. Conclusion: In non-obstructive CAD, serial CCTA demonstrated a higher total plaque burden and a stable plaque composition in women, while men had a faster progression of unstable low-attenuating fibro-fatty plaques.