Impact of coronary artery calcification on all-cause mortality in individuals with and without hypertension.
BACKGROUND
Coronary artery calcium (CAC) has emerged as an important prognostic indicator for coronary heart disease risk. The purpose of this study was to assess the impact of increasing CAC burden among those with and without hypertension (HTN).


METHODS
The study cohort consisted of 44,052 consecutive asymptomatic individuals free of known coronary heart disease referred for electron beam computed tomography (EBT) for the assessment of subclinical atherosclerosis. Patients were followed for a mean of 5.6 ± 2.6 years (range 1-13 years). The primary endpoint for the study cohort was mortality from any cause.


RESULTS
About one third (34%) of the subjects were affected by hypertension. There were 901 deaths (2.05%) in the total study population over a mean follow-up of 5.6 ± 2.6 years (range 1-13 years). The lowest event rate was observed in those with no CAC among those without hypertension (1.6 events per 1000 person years), whereas those with CAC ≥400 and hypertension had the highest all fatality rate (9.8 per 1000 person years). Compared to a CAC score of 0, increasing CAC scores (1-99, 100-399, and ≥400) were associated with increases in all-cause mortality. The hazard ratio was 2.19-7.74-fold among those without HTN and 3.00-5.83 fold among those with HTN. Overall likelihood ratio chi square statistics demonstrated that the addition of CAC scores increased mortality prediction beyond traditional risk among those with hypertension.


CONCLUSIONS
Addition of CAC scores contributed significantly in predicting mortality in addition to just traditional risk factors alone among those with and without hypertension.
Johns Hopkins Ciccarone Center for the Prevention of Heart Disease, Baltimore, MD, USA.
Garth
G
Graham
Michael J
MJ
Blaha
Matthew J
MJ
Budoff
Juan J
JJ
Rivera
Arthur
A
Agatston
Paolo
P
Raggi
Leslee J
LJ
Shaw
Daniel
D
Berman
Jamal S
JS
Rana
Tracy
T
Callister
John A
JA
Rumberger
James
J
Min
Roger S
RS
Blumenthal
Khurram
K
Nasir
D000328:Adult; D000368:Aged; D001794:Blood Pressure; D002423:Cause of Death; D016009:Chi-Square Distribution; D017023:Coronary Angiography / Q000379:methods; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging / Q000401:mortality*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000175:diagnosis / Q000401:mortality* / Q000503:physiopathology; D053208:Kaplan-Meier Estimate; D016013:Likelihood Functions; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016016:Proportional Hazards Models; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D014481:United States / Q000453:epidemiology; D061205:Vascular Calcification / Q000000981:diagnostic imaging / Q000401:mortality*