CAC Score of Zero at Age 73: Prevalence and Clinical Significance

Prevalence in Older Adults

A CAC score of zero at age 73 is uncommon but not rare, occurring in approximately 10-20% of individuals in this age group, and represents an exceptionally favorable cardiovascular prognosis regardless of other risk factors 1
In large asymptomatic cohorts, approximately 41% of all patients across age groups had CAC = 0, though this percentage decreases substantially with age, and age is the strongest predictor of CAC presence 1, 2
The MESA model demonstrates that a CAC score of 100 corresponds to an arterial age of approximately 73 years, suggesting that zero calcium at this chronological age represents a vascular age significantly younger than expected 2

Annual mortality remains <1% for over 15 years in patients with CAC = 0, and this favorable prognosis holds true even for those classified as high risk by traditional risk scores 3
The event rate for an 80-year-old with CAC = 0 and no other risk factors approximates that of an average 50-year-old with no risk factors, demonstrating the powerful risk-downgrading effect of zero calcium 2
In systematic reviews, only 0.47% of asymptomatic patients with CAC = 0 experienced adverse cardiovascular events during 50-month follow-up 1

The presence of risk factors can truncate the durability of the zero CAC "warranty period," particularly in diabetic patients after 5 years 2, 3
While no difference in 5-year mortality exists between diabetic and nondiabetic CAC = 0 patients, diabetic patients show a nonlinear increase in mortality after 5 years 3