Background: Augmentation index (AIx) is considered as an important predictor of cardiovascular disease. So, quantification of AIx may provide a rapid cost-effective and non-invasive means of cardiovascular risk stratification. At present, WHO/ISH risk prediction charts are used to predict 10-year risk of a fatal or nonfatal major cardiovascular event, an assessment which requires laboratory support for blood chemistry and thus making it ill-suited for resource-limited settings.
Objectives: In this study, we examined the association of AIx with cardiovascular risk as determined by the WHO/ISH chart and identified AIx cut-offs to stratify patients into different risk categories.
Methods: A case-control study with 162 cases and 61 controls was conducted in a tertiary care hospital in eastern India. Data were obtained for demographic, anthropometric, cardiovascular, and biochemical parameters. Cardiovascular risk assessment was done by WHO/ISH risk model in R. Statistical analysis was done for examining the association of AIx with WHO/ISH cardiovascular risk and for identifying AIx cut-offs to stratify patients into different risk categories.
Results: Box and whisker plots for assessing the correlation between AIx and WHO/ISH cardiovascular risk showed increase in median value of AIx with increasing risk in both cases and controls. Heart rate corrected AIx showed a steady increase with increasing risk in males. AIx cut-offs showed good sensitivity and specificity for each risk category.
Conclusions: AIx is remarkably associated with cardiovascular risk as assessed by WHO/ISH chart and the AIx cut-offs obtained in the study can be used as an efficient, non-invasive surrogate biomarker of cardiovascular risk even in resource-limited settings.