RISK RECLASSIFICATION AND COST-EFFECTIVENESS OF ECHOCARDIOGRAPHY FOR CARDIOVASCULAR PRIMARY PREVENTION IN HYPERTENSION

Objective: We aimed to assess risk reclassification and cost-effectiveness of echocardiography for cardiovascular primary prevention in hypertension.Design and method: This is a retrospective cohort study. Community hypertensive patients without cardiovascular disease (CVD) were included from the 2016-2020 China PEACE Project (n=3,243; mean age was 58.5 years; women were 56.6%). Discriminative performance of adding echocardiographic measures to conventional clinical model was assessed. Based on mean incidence rate of major adverse cardiovascular events (MACE), participants were classified into low-risk, intermediate-risk, or high-risk categories. Number needed to test (NNT) and cost of echocardiography for screening one intermediate-risk and one high-risk individual were calculated. Results: After a mediate follow-up of 4.5-year, 368 participants (11.3% of the cohort) had MACE. Adding subclinical cardiac changes on echocardiography significantly improved discriminative performance of conventional clinical model, with C-statistic increased by 0.028 (P-value=0.003). Presence of subclinical cardiac changes led to reclassification of 18% of low-risk patients into intermediate-risk and 4% into high-risk categories. Based on the differences in the absolute rate of MACE between low-risk group and intermediate-risk and high-risk groups, 77 (USD 3,080) and 11 (USD 440) echocardiographic examinations were needed to identify one intermediate-risk and one high-risk individual respectively at the first-year follow-up. These numbers decreased to 27 (USD 1,080) and 7 (USD 280) at the second-year follow-up; and further declined to 20 (USD 800) and 6 (USD 240) at the third-year follow-up. Echocardiography is cost-effective based on the monetary value of a quality-adjusted life year in China (USD 14,952). Conclusions: Results of this study demonstrate the potential of risk reclassification and cost-effectiveness of echocardiography for cardiovascular primary prevention in hypertension.