30-Year Follow-up of the Coronary Artery Calcium Consortium

PROJECT SUMMARY
The Coronary Artery Calcium Consortium (CAC Consortium) is a large, multi-center, retrospective clinical
cohort study funded from 2013-2015 by the NHLBI to study the cardiovascular and non-cardiovascular
prognostic value of CAC scanning in clinical practice. Despite its productivity, a major limitation for the CAC
Consortium is the relatively short follow-up, with vital status ascertainment last conducted in 2014. This
limitation becomes more important in an era of 30-year risk prediction ushered in by the publication of the
PREVENT equations, as there are no data on the implications of CAC scoring over the 30-year time horizon.
We seek to leverage the agreement between the National Institutes of Health (NIH) and the National Death
Index (NDI) to extend CAC Consortium follow-up, with important scientific implications for 30-year risk
estimation in young to middle-aged adults (age 30-59). Under this proposal, a total of ~5000 patients aged 30-
59 will have 30-year follow-up, and ~30,000 patients will have at least 25-year follow-up, providing sufficient
statistical power for our scientific aims. In Aim 1, we see to quantify 30-year survival in patients aged 30-59
with baseline CAC=0. We hypothesize the older patients will gain a great survival advantage compared to
younger patients compared to the general age-matched population. In Aim 2, we seek to describe the 10- and
30-year prognosis of individuals aged 30-59 with low absolute CAC scores between 1 and 100. While these
patients have a low absolute CAC score, their percentile score is high, which may correlate with similarly poor
survival to old age compared to older patients with higher absolute CAC scores. In Aim 3, we seek to evaluate
the improvement in 30-year cardiovascular mortality risk prediction when CAC is added to the PREVENT
equations. This extended follow-up of the CAC Consortium will leverage previous NHLBI investment in this
project and fill critical knowledge gaps that could not be addressed with any other dataset, with specific
implications for the critical age range (30-59 years old) where guidelines recommend risk assessment over a
30-year time horizon. We believe this work will have specific implications for future ACC/AHA Prevention
Guidelines, which will likely incorporate recommendations based on long-term risk prediction.

Grant Number: 1R21HL181646-01
NIH Institute/Center: NIH
Principal Investigator: MICHAEL BLAHA