Coronary artery calcium (CAC) scoring among adults with hypertension may help identify those at risk for cardiovascular disease (CVD) and inform them about the best blood pressure treatments, according to a study recently published in Hypertension.
In this study, 16,167 patients with hypertension from the CAC Consortium were studied to determine the effectiveness of CAC as a risk-stratification tool. Among these, 6375 also were eligible for the Systolic Blood Pressure Intervention Trial (SPRINT). The researchers studied the association of different CAC scores with coronary heart disease hazard ratios, CVD hazard ratios, and CVD mortality rates among participants over 50 years old.
CAC scores in the range of 100 to 399 were associated with a coronary heart disease hazard ratio of 1.88 and a CVD hazard ratio of 1.93. CAC scores of 400 or more were associated with a coronary heart disease hazard ratio of 4.16 and a CVD hazard ratio of 3.51. A CAC score of 220 in individuals over 50 years old also correlated with the CVD mortality rate reported in SPRINT. This indicates that a combined CAC/atherosclerotic CVD-risk measurement could help identify high-risk patients needing aggressive blood pressure therapy.
This study boasts one of the largest study populations with hypertension and may be the first CAC-based study to use the atherosclerotic CVD 10% cut point. It demonstrated how CAC can recategorize risk around this threshold.
Although it is a validated way to collect risk-factor data, one study limitation is participant self-reporting of hypertension and other risk factors posing a potential for recall bias. Another limitation of this study includes the fact that participants were clinically referred for CAC scoring, potentially limiting how generalizable these results can be. Information such as the presence of chronic kidney disease, which is commonly collected for SPRINT, was not collected in this study.
The researchers demonstrated that CAC scoring can risk-stratify patients with hypertension, including those who are SPRINT eligible and can recategorize risk around the atherosclerotic CVD 10% threshold. They also concluded that a CAC score of around 220 can identify patients with hypertension with risk equivalent to the SPRINT study.
Uddin SMI, Mirbolouk M, Kianoush S, et al. Role of coronary artery calcium for stratifying cardiovascular risk in adults with hypertension [published online March 18, 2019]. Hypertension. doi: 10.1161/HYPERTENSIONAHA.118.12266