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Garth Graham,
Michael J Blaha,
Matthew J Budoff,
Juan J Rivera,
Arthur Agatston,
Paolo Raggi,
Leslee J Shaw,
Daniel Berman,
Jamal S Rana, Tracy Callister,
John A Rumberger,
James Min,
Roger S Blumenthal,
Khurram Nasir
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ABSTRACT: 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. CONCLUSION: Addition of CAC scores contributed significantly in predicting mortality in addition to just traditional risk factors alone among those with and without hypertension.
Atherosclerosis 09/2012; · 3.79 Impact Factor
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Rajesh Tota-Maharaj,
Michael J Blaha,
John W McEvoy,
Roger S Blumenthal,
Evan D Muse,
Matthew J Budoff,
Leslee J Shaw,
Daniel S Berman,
Jamal S Rana,
John Rumberger, Tracy Callister,
Juan Rivera,
Arthur Agatston,
Khurram Nasir
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ABSTRACT: AimsTo determine if coronary artery calcium (CAC) scoring is independently predictive of mortality in young adults and in the elderly population and if a young person with high CAC has a higher mortality risk than an older person with less CAC.Methods and resultsWe studied a cohort of 44 052 asymptomatic patients referred for CAC scans for cardiovascular risk stratification. All-cause mortality rates (MRs) were calculated after stratifying by age groups (<45, 45-54, 55-64, 65-74, and ≥75) and CAC score (0, 1-100, 100-400, and >400). Multivariable Cox regression models were constructed to assess the independent value of CAC for predicting all-cause mortality in the <45- and ≥75-year-old age groups. The MR increased in both the <45- and ≥75-year-old age groups with an increasing CAC group. After multivariable adjustment, increasing CAC remained independently predictive of increased mortality compared with CAC = 0 [<45 age group, hazard ratio (95% confidence interval): CAC = 1-100, 2.3 (1.2-4.2); CAC = 100-400, 7.4 (3.3-16.6); CAC > 400, 34.6 (15.5-77.4); ≥75 age group: CAC = 1-100, 7.0 (2.4-20.8); CAC = 100-400, 9.2 (3.2-26.5); CAC > 400, 16.1 (5.8-45.1)]. Persons <45 years old with CAC = 100-400 and CAC > 400 had 2- and 10-fold increased MRs, respectively, compared with persons ≥75 with no CAC. Individuals ≥75 years old with CAC = 0 had a 5.6-year survival rate of 98%, similar to those in other age groups with CAC = 0 (5.6-year survival, 99%).Conclusion
The value of CAC for predicting mortality extends to both elderly patients and those <45 years old. Elderly persons with no CAC have a lower MR than younger persons with high CAC.
European Heart Journal 07/2012; · 10.48 Impact Factor
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Khurram Nasir,
Jonathan Rubin,
Michael J Blaha,
Leslee J Shaw,
Ron Blankstein,
Juan J Rivera,
Atif N Khan,
Daniel Berman,
Paolo Raggi, Tracy Callister,
John A Rumberger,
James Min,
Steve R Jones,
Roger S Blumenthal,
Matthew J Budoff
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ABSTRACT: Current guidelines recommend the use of coronary artery calcium (CAC) scoring for intermediate-risk patients; however, the potential role of CAC among individuals who have no risk factors (RFs) is less established. We sought to examine the relationship between the presence and burden of traditional RFs and CAC for the prediction of all-cause mortality.
The study cohort consisted of 44,052 consecutive asymptomatic individuals free of known coronary heart disease referred for computed tomography for the assessment of CAC. The following RFs were considered: (1) current cigarette smoking, (2) dyslipidemia, (3) diabetes mellitus, (4) hypertension, and (5) family history of coronary heart disease. Patients were followed for a mean of 5.6 ± 2.6 years for the primary end point of all-cause mortality. Among individuals who had no RF, Cox proportional model adjusted for age and sex identified that increasing CAC scores were associated with 3.00- to 13.38-fold higher mortality risk. The lowest survival rate was observed in those with no CAC and no RF, whereas those with CAC ≥ 400 and ≥3 RFs had the highest all-cause fatality rate. Notably, individuals with no RF and CAC ≥ 400 had a substantially higher mortality rate compared with individuals with ≥3 RFs in the absence of CAC (16.89 versus 2.72 per 1000 person-years).
By highlighting that individuals without RFs but elevated CAC have a substantially higher event rates than those who have multiple RFs but no CAC, these findings challenge the exclusive use of traditional risk assessment algorithms for guiding the intensity of primary prevention therapies.
Circulation Cardiovascular Imaging 06/2012; 5(4):467-73. · 5.94 Impact Factor
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Michael Gordon Silverman,
Michael J Blaha,
Matthew J Budoff,
Juan J Rivera,
Paolo Raggi,
Leslee J Shaw,
Daniel Berman, Tracy Callister,
John A Rumberger,
Jamal S Rana,
Roger S Blumenthal,
Khurram Nasir
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ABSTRACT: It is unclear whether coronary artery calcium (CAC) is effective for risk stratifying patients with diabetes in whom treatment decisions are uncertain.
Of 44,052 asymptomatic individuals referred for CAC testing, we studied 2,384 individuals with diabetes. Subjects were followed for a mean of 5.6 ± 2.6 years for the end point of all-cause mortality.
There were 162 deaths (6.8%) in the population. CAC was a strong predictor of mortality across age-groups (age <50, 50-59, ≥60), sex, and risk factor burden (0 vs. ≥1 additional risk factor). In individuals without a clear indication for aspirin per current guidelines, CAC stratified risk, identifying patients above and below the 10% risk threshold of presumed aspirin benefit.
CAC can help risk stratify individuals with diabetes and may aid in selection of patients who may benefit from therapies such as low-dose aspirin for primary prevention.
Diabetes care 03/2012; 35(3):624-6. · 8.09 Impact Factor
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ABSTRACT: We sought to quantify the mortality rates associated with absent and low positive (CAC 1 to 10) coronary artery calcium (CAC).
There is increasing interest in the absence of CAC as a "negative" cardiovascular risk factor. However, published event rates for individuals with no CAC vary, likely owing to differences in baseline risk, follow-up period, and outcome ascertainment. The prognostic significance of low CAC (CAC 1 to 10) is not well described.
Annualized all-cause mortality rates were assessed in 44,052 consecutive asymptomatic patients referred for CAC testing. Mean follow-up of the cohort was 5.6 +/- 2.6 years (range 1 to 13 years).
A total of 19,898 patients (45%) had no CAC on screening electron beam tomography, whereas 5,388 (12%) had low levels of CAC (CAC 1 to 10), and 18,766 (43%) had CAC >10. There were 104 deaths in those with no CAC (0.52%), 58 deaths in those with CAC 1 to 10 (1.06%), and 739 deaths in those with CAC >10 (3.96%). Annualized all-cause mortality rates for CAC = 0, CAC 1 to 10, and CAC >10 were 0.87, 1.92, and 7.48 deaths/1,000 person-years, respectively. The hazard ratio (HR) for all-cause mortality among CAC 1 to 10 versus CAC = 0 after adjustment for traditional risk factors was 1.99 (95% confidence interval [CI]: 1.44 to 2.75). Smoking (HR: 3.97, 95% CI: 2.75 to 5.41) and diabetes mellitus (HR: 3.36, 95% CI: 2.09 to 5.41) were associated with few events observed in CAC = 0 group.
In appropriately selected asymptomatic patients, the absence of CAC predicts excellent survival with 10-year event rates of approximately 1%. A finding of 0 CAC might be used as a rationale to emphasize lifestyle therapies rather than pharmacotherapy and to forgo repeated imaging studies. Individuals with low CAC score (CAC 1 to 10) are at increased risk above individuals with a 0 score and could be considered a distinct risk group by physicians and investigators.
JACC. Cardiovascular imaging 06/2009; 2(6):692-700. · 14.29 Impact Factor
