Assessment of Aortic Stiffness in Obstructive Sleep Apnea: Implications for Cardiovascular Health

1. ASSESSMENT OF AORTIC STIFFNESS WHICH IS A NEW CARDIOVASCULAR MORBIDITY AND MORTALITY PREDICTOR IN PATIENTS WITH OBSTRUCTIVE SLEEP APNEA SYNDROME AND RELATION WITH SEVERITY OF THE DISEASE • Yusuf Tavil1, Oğuz Köktürk2, Tansu Ulukavak Çiftçi2, Asiye Kanbay2, Nihat Şen1, M.Rıdvan Yalçın1, Atiye Çengel1 Gazi University Faculty of Medicine, Departments of Cardiology1 and Pulmonary Medicine2, Ankara

2. OSAS & Heart (1) • The recurrent sleep arousal in association with intermittent hypoxia and hypercapnia has been implicated in the occurrence of adverse cardiovascular outcomes

3. OSAS & Heart (2) • 􀁺Hypertension • 􀁺Ischemic heart disease • 􀁺Cardiac arrhythmias • 􀁺Cerebral infarction 􀁺 • 􀁺Pulmonary hypertension • Subclinic Right&left heart failure

4. OSAS & Heart (3) • 􀁺Associations between sleep apnea, hypertension, heart disease, and stroke raise the possibility of common factors and/or causal relationships between sleep apnea and cardiovascular disorders • 􀁺Such links may be related to biochemical factors such as insulin, catecholamine, or cortisol that are increased in stress • 􀁺Alternately obesity, sleep apnea, and other cardiovascular risk factors may share common metabolic pathways and therefore may be genetically determined

6. Arterial & Aortic Stiffness(1) • Arterial stiffness in large arteries has been reported to be the best predictor of cardiovascular morbidity and mortality • The measurement of arterial stiffness; • Pressure/distension changes • Pulse wave velocity • Pulse wave analysis

7. Arterial & Aortic Stiffness(2) • Pulse pressure was measured by cuff sphygmomanometry of the brachial artery and not invasively in the ascending-Ao. However, several reports have demonstrated the excellent correlation of the non-invasively calculated aortic function indexes with indexes derived from aortography

8. PWV and PWA are subject to confounding factors – Blood pressure – increases PWV and AIx – Heart rate – may increase PWV and decrease – Body height – decreases AIx

9. Arterial & Aortic Stiffness(3) • Aortic distensibility is an important determinant of left ventricular (LV) function and coronary blood flow Additionally, aortic distensibility has been related to increased cardiovascular mortality in different populations.

10. Study protocol: • 40 patients with OSAS and 25 age and BMI-matched control without heart and pulmonary disease • Both groups have the same basal characteristics • Corelation analysis have made independent from age and body mass index

11. Aortic distensibility was determined non-invasively based on the relationship between changes in aortic diameter and pressure with each cardiac pulse. Ascending aorta was recorded at a level 3 cm above the aortic valve in the M-mode tracing guided by the two-dimensional echocardiogram in the parasternal long-axis view.

12. Aortic strain (%) = (aortic systolic diameter - diastolic diameter) x100 / diastolic diameter • Distensibility (10-6 cm2 dyn–1) = (2x Aortic strain) / (systolic pressure - diastolic pressure)

13. Results: * p<0.005

15. AHI ile Aortic strain ilişkisi AHI ile aotic distensibilite ilişkisi

16. In conclusion, decreased aortic stiffness parameters in OSAS patients according to severity of disease, is a new markers of elevated cardiovascular risk in these patients.