PT  - JOURNAL ARTICLE
AU  - Leong Chai Leow
AU  - Lohendran Baskaran
AU  - Swee Yaw Tan
AU  - Thun How Ong
TI  - Impact of different hypopnea definitions on predictive accuracy of apnea hypopnea index for coronary artery calcification
DP  - 2014 Sep 01
TA  - European Respiratory Journal
PG  - P2010
VI  - 44
IP  - Suppl 58
4099  - http://erj.ersjournals.com/content/44/Suppl_58/P2010.short
4100  - http://erj.ersjournals.com/content/44/Suppl_58/P2010.full
SO  - Eur Respir J2014 Sep 01; 44
AB  - Obstructive Sleep Apnea(OSA) is associated with cardiovascular disease(CVD). The change in hypopnea definition from a 4% to a 3% desaturation criteria in the 2012 American Academy of Sleep Medicine (AASM) scoring update have resulted in marked increases in Apnea Hypopnea Indices (AHI) and led to concerns about over diagnosis. It is unclear which scoring criterion is more accurate in predicting underlying cardiovascular risk.We explored the relationship between coronary artery calcification and AHI obtained using the 2012 AASM 3% desaturation criteria(AHI2012) when compared to the 2007 AASM 4% desaturation criteria(AHI2007) for hypopneas.Patients with no known CVD who were diagnosed with OSA(AHI2007>5) from a level 1 polysomnography (PSG) received a non-contrast cardiac CT. PSGs were scored using the 2007 AASM criteria then rescored using the 2012 AASM criteria in a blinded manner, and their association with coronary artery calcium scores (CAC) were compared.81 patients participated with a median age of 50. Median AHI2007 was 27.8 and median AHI2012 was 36.9. CAC scores were less than 11, 11-400 and more than 400 in 62%, 33% and 5% of the cohort respectively. AHI2012 correlated with high CAC score >400, (rho 0.24, p=0.03) but not AHI2007 (rho 0.20, p=0.07). Comparison by ROC curve analysis showed no significant differences in predictive accuracy of the AHI2007 compared to AHI2012 for high CAC >400 (c statistic 0.77 versus 0.82, p=0.24)In this prospective cohort study of OSA patients with no known CVD, AHI2012 correlated better with high CAC score>400 compared to AHI2007, but the predictive accuracies of AHI2007 and AHI2012 for high CAC scores were similar.