Renal dysfunction predicts the presence and extent of coronary artery disease on coronary CT angiography

Background: Impaired renal function is a well known marker of cardiac risk. Prior data suggests it is associated with the extent of obstructive disease on invasive coronary angiography and with a higher coronary calcium score. However, no prior study has evaluated its association with the presence and severity of atherosclerosis evaluated by coronary computed tomography angiography (CCTA). We have aimed to evaluate the relationship between renal dysfunction, quantified by glomerular filtration rate (eGFR) and the presence and severity of coronary artery disease (CAD) by CCTA. Methods: CCTA scans performed at two tertiary hospitals within Partners Healthcare system (Boston, Massachusetts) between 09/2004 and 10/2011 were retrospectively analyzed. We included ali consecutive patients who underwent CCTA who were > 18 years old without known prior•CAD and had at least one value of creatinine available in a one year interval prior to the scan. The eGFR was estimated by the MDRD formula. CGTA was evaluated using the AHA/ ACC 17- segment model. Each segment was categorized as normal, non-obstructive (<50%) or obstructive (≥50%). The extent of disease was calculated using scores based on the number of segments with non-obstructive and obstructive disease. The association of eGFR with the presence and extent of disease was computed using logistic regression. Results: 1692 (40% female) patients were included. The mean age was 54.7 ± 13.7.722 (43%) of the patients had no CAD on the coronary CT, 599 (35%) had non-obstructive and 371 (22%) had obstructive CAD. 434 patients had a eGFR >90 mL/min/ 1.73 m2 (group 0), 1129 had a eGFR 60-90 mL/min/1.73 m2 (group 1),199 had eGFR between 45-60 mL/min/1.73 m2 (group 2) and 74 had eGFR <45 mL/min/1.73 m2 (group 3). The odds ratios (OR) were 1.27, 2.41 and 3.25 for groups 1-3, respectively, compared to group 0 for the presence of any CAD (p<0.0001). Similarly the ORs were 1.46, 2.82 and 5.02, respectively, for the presence of obstructive disease (p<0.0001). The eGFR was significantly associated with both the involvement and the severity scores (p