P2786Current ESC guidelines for normal ascending aortic diameter: prevalence of aortic dilatation increases to 20% in a consecutive coronary CTA population

Abstract

Abstract Introduction Epidemiological studies on the prevalence of ascending aortic (AA) dilatation are scanty. Purpose To clarify prevalence of AA dilatation according to ESC 2014 guidelines and to study its risk factors. Methods This retrospective study included 1000 consecutive patients scheduled for diagnostic coronary artery computer tomography angiography (CCTA) with low to moderate pretest probability for coronary artery disease (CAD). AA diameter was measured at 3 planes; sinus valsalva, sinotubular junction and tubular part. Threshold for AA dilatation was set to >40 mm (ESC 2014). Traditional risk factors for AA dilatation were collected from medical records. Aortic size index (ASI) was used as a comparative measurement. ASI is defined as the ratio between aortic diameter and body surface area (BSA). The threshold for AA dilatation was set to upper limit of normal distribution exceeding two standard deviations (95%). Heart-aorta angle (HAA, Figure) was measured as one suggestive risk factor. Results Patients' mean age was 52.9±9.8 years, 66.5% were women. The prevalence of AA dilatation in the whole study population was 20.4% according to ESC 2014 guidelines. When patients with hypertension (n=445) or coronary calcifications or stenosis in CCTA (n=375) were excluded, the prevalence of AA dilatation was 14.5% in the population of normotensive patients without CAD (n=380). According to the normal-distributed ASI values the threshold for normal dimension of sinus valsalva was defined as 23.5 mm/m2 and for tubular part 22.7 mm/m2 for normotensive patients without CAD. Using these thresholds, the prevalence of AA dilatation was 7.8% in the whole population and 7.1% in normotensive patients without CAD. Smaller HAA was associated to AA dilatation. Median HAA was 125.6° (range: 119.2–131.5°) in patients with dilated AA and 130.1° (123.7–136.4°) in patients with non-dilated AA (p<0.001). Higher BSA was associated to larger AA dimensions. Risk factors for AA dilatation (according to ESC criteria) were male gender, BAV, hypertension and smoking (p<0.01). Figure 1 Conclusions The prevalence of AA dilatation proved to be relatively high in this consecutive CCTA population when using ESC 2014 guidelines. Body size is associated to AA dimensions; thus, it seems reasonable to include BSA in the definition of AA dilatation. Acknowledgement/Funding Oiva Vaittinen will grant, Aarne Koskelo Foundation