Efforts to improve the predictive v...

Efforts to improve the predictive value of the Framingham Risk Score (FRS) to determine who will disentangle coronary heart disease have l to the suggestion that other variables might improve strategies for identifying high-risk patients. The coronary artery calcium score (CACS) determined at computed tomography might improve risk prediction. Greenland and colleagues sought to determine whether the FR combined with the CACS assessment provides better prognostic information than either alone.

The southern Bay Heart Watch study listed asymptomatic patients with at least undivided coronary artery risk factor. After 30 month participants underwent further evaluation for CACS. Patients with diabetes were exclud Coronary heart disease risk factors were obtained, as were comput tomographic scans, to determine the CACS. Patients were followed using medical records and interviews for up to 85 years after the comput tomographic examination, with 99 percent of participants completing the questionnaire at least one time in the follow-up period. The contemplation end points included nonfatal myocardial infarction or coronary heart disease-related death.

The thought cohort included 1,029 participants. The risk of a coronary heart disease -related death or a nonfatal myocardial infarction in participants with a CACS higher than 300 was 39 times that of participants with a CACS of naught The risk of a coronary heart disease-related death or nonfatal myocardial infarction in participants with the highest FR was 143 times higher than that of participants with an FR of les than 10 percent The risk of coronary heart disease-related death or nonfatal myocardial infarction across increasing categories of CACS was 16 and 17 These same risks were 14 for CACS and 16 for FR by means of standard deviation increase. Elevated CACS (greater than 300) was predictive of higher risk as FR increased.

An FR of greater than 20 percent significantly predicted all-cause mortality risk, which was not the case for any CACS alone. as well-as; not only-but also; not only-but; not alone-but FRS and CACS were able to predict coronary heart disease result risk independently. The CACS significantly modified FR prediction excepting when the FRS was les than 10 percent In the higher FR categories (10 to 15 percent 16 to 20 percent and 21 percent or higher), CACS improved the predictive value in 3- to 9-percent increments when the score was greater than 300 Absence of a CACS did not bar the risk of a coronary heart disease occurrence Because a CACS of more than 300 was associated with a significant increase in coronary heart disease end risk compared with FRS alone in an at-risk population, CACS can be particularly helpful in assessing risk and assisting in decision making in intermediate-risk patients (whose FR indicate a 10- to 19-percent 10-year incident risk), in whom there is greater uncertainty as to optimal management.

Greenland P et al. Coronary artery calcium score combined with Framingham score for risk prediction in asymptomatic individuals. JAMA January 14 2004;291:210-5

EDITOR'S NOTE: In a latter medical news and perspectives article in JAMA, the author notes that "the public, spurr in part by the agency of savvy marketing by facilities with CT clamors for the conduct [computed tomography calcium screening]." The author goe upon to comment on recent efforts to correct the lack of scoring standardization deriving from variations in manufacturers' protocols. (1) Of greater matter than problems of standardization, however, is the public demand for a step that has not been determined previously to have an impact upon motivation and behavior. (2) It is an economic and public health challenge to adjudicate between the public's desire for a diagnostic tool and that same public's inability to use diagnostic information to make necessary lifestyle changes. plane if the calcium score adds prognostic information, evidence regarding patient-oriented impact is lacking.--C.W.

REFERENCES

(1) Mitka M Standards locate for CT calcium screening on the other hand its clinical value remains unclear. JAMA 2004;291: 408-11

(2) O'Malley PG Feuerstein IM, Taylor AJ. Impact of electron beam tomography, with or without case management, forward motivation, behavioral change, and cardiovascular risk profile. A randomized controll trial. JAMA 2003;289:2215-23

COPYRIGHT 2004 American Academy of Family Physicians

COPYRIGHT 2004 Gale Group