11.7 AORTIC CALCIUM SCORE AFFECTS NON-INVASIVELY OBTAINED ESTIMATES OF CENTRAL BLOOD PRESSURE IN PATIENTS WITH ADVANCED CHRONIC KIDNEY DISEASE

Abstract

Background: We recently reported that central blood pressure (BP) obtained non-invasively in chronic kidney disease (CKD) patients significantly underestimated the central BP with decreasing eGFR in comparison with invasively measured true central BP in the aorta. This post-hoc analysis investigated whether the presence of aortic calcification affected non-invasive estimates of central BP. Methods: CKD stage 4–5 patients undergoing coronary angiography were included. Invasive aortic BP was measured through angiography catheters. Non-invasive central BP was obtained with the SphygmoCor device. Calcium score (CS) in the aorta was quantified using CT. Results: Twenty-four patients were enrolled (meanSD): 63% males, age 53±11 years, and eGFR 95 ml/min/1.73 m2. Invasive aortic SBP was 152±23 mmHg. Estimated central SBP was 133±20 mmHg. Ten patients had a CS=0 in both ascending and descending aorta, 2 patients had ascending aortic CS>0 while 8 patients had descending aortic CS>0 and 4 patients had both ascending and descending aortic CS>0. In patients with CS>0 in the descending aorta, central SBP was underestimated by 4(117) mmHg (P=0.02) compared to patients with CS=0. No significant difference was found between patients with and without calcium in the ascending aorta (P=0.13). In patients with CS>0 in both descending and ascending aorta central SBP was underestimated by 14(326) mmHg (P=0.02) compared to patients with CS=0 in both segments. Conclusion: In advanced CKD, aortic calcification significantly affected the difference between estimated and invasively measured central BP. This may question the usefulness of non-invasive estimates of central BP in high-risk patients with severe aortic calcification.