Jukema, R. A., et al. “Increased RAAS activation is associated with calcified plaque burden, adverse plaque characteristics and FFR significant coronary artery disease.” Atherosclerosis 355 (2022): 2. https://doi.org/10.1016/j.atherosclerosis.2022.06.234
Background and Aims : Renin-angiotensin-aldosterone-system (RAAS) activity has been linked to coronary artery disease (CAD) and coronary microvascular dysfunction (CMD). In this study we investigated if increased RAAS activation is related to CAD, high risk plaque (HRP), myocardial perfusion and CMD in chest pain patients.
Methods: Venous renin as a measure for RAAS activation was quantified by immunoradiometric assay in 205 patients (64% men; age 58 ± 9 years) with suspected CAD. Patients underwent 256-slice coronary CT angiography for (quantitative) plaque analysis and coronary artery calcium (CAC) scoring, [15O]H2O PET perfusion imaging and invasive FFR measurements in all coronary arteries. Patients were categorized into three groups based on FFR (≤0.80) and hyperemic MBF <2.3 ml/min/g: (1)obstructive CAD (n=92), (2)CMD (n=26) or (3)no or nonobstructive CAD (n=85).
Results: Significant associations were found between renin and CAC score, TPV and MBF (r=0.22; r=0.23; r=-0.19 respectively, p<0.001 for all). After correction for baseline characteristics including RAAS inhibiting therapy renin associated positively with CAC score and TPV, but not with hyperemic MBF (p<0.01; p=0.02 and p=0.23). Patients with high risk plaque displayed higher levels of renin (mean logarithmic renin 1.25±0.43 vs. 1.12±0.35 pg/ml; p=0.04). Compared to no or nonobstructive CAD patients, renin was significantly elevated in obstructive CAD patients but not in CMD patients (mean logarithmic renin 1.06±0.34 vs. 1.23±0.36; p<0.01 and 1.06±0.34 vs. 1.16±0.41 pg/ml; p=0.65).
Conclusions: RAAS activity measured by renin concentration is elevated in patients with coronary atherosclerosis and high risk plaque but not in patients with CMD.