Abstract Body (Do not enter title and authors here): Background: The American Heart Association recently released the Predicting Risk of cardiovascular disease EVENTs (PREVENT) equation for estimating cardiovascular disease (CVD) risk in primary prevention adults aged 30-79. However, its performance in older adults aged 80 years and older is uncertain. Also, the utility of coronary artery calcium (CAC) for CVD prediction improvement beyond PREVENT is unknown.
Methods: We studied 1,912 ARIC older adult participants (mean age 80 [SD 4] years) with CAC data but without a history of coronary heart disease (CHD), stroke, and heart failure (HF) at Visit 7 (2018-2019). We first assessed c-statistics and calibration indices of the PREVENT in our older adult population. Then, we compared the predictability between PREVENT and CAC, with total CVD (atherosclerotic CVD [ASCVD, including CHD and stroke] and HF), and all-cause mortality as outcomes of interest, using Cox regression models.
Results: Over a median follow-up of 3.7 (IQI 2.6-4.3) years, there were 144 CVD events (81 ASCVD and 75 HF) and 210 deaths. PREVENT demonstrated good calibration (calibration slope 0.74 for total CVD) and discrimination (c-statistic 0.621), and the results were similar in participants aged 80+ vs. those aged 75-79 years. CAC significantly improved prediction of total CVD (0.078 [95% CI 0.034, 0.122]), ASCVD (0.083 [0.026, 0.140]), and HF (0.069 [0.016, 0.123]) beyond PREVENT, but this was not the case for all-cause mortality (left panel of Figure). In contrast, PREVENT improved only the prediction of all-cause mortality beyond CAC (right panel of Figure). The results were largely similar between the age of 80+ vs. 75-79.
Conclusions: PREVENT overall performed well even in older adults aged 80+ years. CAC further improved CVD risk prediction beyond and above PREVENT in the-75-and-older adults. Our findings suggest broad usefulness of PREVENT and further support the value of CAC for assessment of primary CVD risk in very older adults.