Limits...
Validity of electron beam computed tomography for coronary artery disease: asystematic review and meta-analysis.

Dendukuri N, Chiu K, Brophy JM - BMC Med (2007)

Bottom Line: In both types of studies, we found variability in EBCT category distribution and risk of CAD within categories.Similar results were obtained for studies of symptomatic patients.However, the non-uniform quality of studies and the lack of availability of individual-level data preclude the extension of our results to individual patients.

View Article: PubMed Central - HTML - PubMed

Affiliation: Technology Assessment Unit, McGill University Health Center, 687 Pine Avenue West R4,09, Montreal, PQ, H3A 1A1 Canada. nandini.dendukuri@mcgill.ca

ABSTRACT

Background: Electron beam computed tomography (EBCT) is a method for measuring coronary calcification and has been promoted as a possible non-invasive screening/diagnostic tool for coronary artery disease (CAD). Our objective was to carry out a systematic review and meta-analysis of EBCT for the screening of asymptomatic patients and the diagnosis of symptomatic patients for CAD.

Methods: Studies were identified from the PUBMED, MEDLINE, EMBASE, Current Contents, INAHTA and Cochrane Collaboration databases. We identified studies published in English evaluating EBCT using: (1) a prospective design among asymptomatic patients where CAD was measured in terms of clinical outcomes (e.g. myocardial infarction, death, revascularization); and (2)a cross-sectional design among symptomatic patients where CAD was measured by coronary angiography. We compared the risk of CAD in EBCT score categories defined as low (0-10), moderate (11-400) and high (>400). A hierarchical meta-analysis was used to pool risk ratios comparing categories across studies.

Results: We identified 9 studies of asymptomatic patients and 10 studies of symptomatic patients. In both types of studies, we found variability in EBCT category distribution and risk of CAD within categories. For studies of asymptomatic patients we estimated the following risk ratios (95% credible intervals): moderate versus low 3.5 (2.4, 5.1) and high versus low 9.9 (5.3, 17.6). Similar results were obtained for studies of symptomatic patients. Ratios comparing the risk of no CAD among symptomatic patients were as follows: moderate versus low 0.5 (0.3, 0.8) and high versus low 0.12 (0.05, 0.2).

Conclusion: Increasing EBCT scores indicate higher risk for CAD in both asymptomatic and symptomatic patients. In general, asymptomatic patients with EBCT scores in the high category can perhaps be considered for preventive medical therapy and risk factor modification. Symptomatic patients with EBCT scores in the low category can perhaps, at least temporarily, avoid invasive coronary angiography. However, the non-uniform quality of studies and the lack of availability of individual-level data preclude the extension of our results to individual patients.

Show MeSH

Related in: MedlinePlus

Distribution of positive predictive values across EBCT score categories.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC2228285&req=5

Figure 2: Distribution of positive predictive values across EBCT score categories.

Mentions: The distributions of EBCT scores as reported in each study are given in Table 5 along with the summary categorization from low to high. The cut-offs reported by individual studies varied greatly, although most studies reported the number of patients with a calcium score of zero. The probability of the outcome increased with increasing EBCT score in all studies (Figure 2 and Table 5). Given the considerable variation between studies in the risk of developing CAD (see Table 5), we concluded that it was not clinically meaningful to pool predictive values across studies. We concentrated instead on pooling the ratios of moderate- or high-risk categories to the baseline low category from each study.


Validity of electron beam computed tomography for coronary artery disease: asystematic review and meta-analysis.

Dendukuri N, Chiu K, Brophy JM - BMC Med (2007)

Distribution of positive predictive values across EBCT score categories.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2228285&req=5

Figure 2: Distribution of positive predictive values across EBCT score categories.
Mentions: The distributions of EBCT scores as reported in each study are given in Table 5 along with the summary categorization from low to high. The cut-offs reported by individual studies varied greatly, although most studies reported the number of patients with a calcium score of zero. The probability of the outcome increased with increasing EBCT score in all studies (Figure 2 and Table 5). Given the considerable variation between studies in the risk of developing CAD (see Table 5), we concluded that it was not clinically meaningful to pool predictive values across studies. We concentrated instead on pooling the ratios of moderate- or high-risk categories to the baseline low category from each study.

Bottom Line: In both types of studies, we found variability in EBCT category distribution and risk of CAD within categories.Similar results were obtained for studies of symptomatic patients.However, the non-uniform quality of studies and the lack of availability of individual-level data preclude the extension of our results to individual patients.

View Article: PubMed Central - HTML - PubMed

Affiliation: Technology Assessment Unit, McGill University Health Center, 687 Pine Avenue West R4,09, Montreal, PQ, H3A 1A1 Canada. nandini.dendukuri@mcgill.ca

ABSTRACT

Background: Electron beam computed tomography (EBCT) is a method for measuring coronary calcification and has been promoted as a possible non-invasive screening/diagnostic tool for coronary artery disease (CAD). Our objective was to carry out a systematic review and meta-analysis of EBCT for the screening of asymptomatic patients and the diagnosis of symptomatic patients for CAD.

Methods: Studies were identified from the PUBMED, MEDLINE, EMBASE, Current Contents, INAHTA and Cochrane Collaboration databases. We identified studies published in English evaluating EBCT using: (1) a prospective design among asymptomatic patients where CAD was measured in terms of clinical outcomes (e.g. myocardial infarction, death, revascularization); and (2)a cross-sectional design among symptomatic patients where CAD was measured by coronary angiography. We compared the risk of CAD in EBCT score categories defined as low (0-10), moderate (11-400) and high (>400). A hierarchical meta-analysis was used to pool risk ratios comparing categories across studies.

Results: We identified 9 studies of asymptomatic patients and 10 studies of symptomatic patients. In both types of studies, we found variability in EBCT category distribution and risk of CAD within categories. For studies of asymptomatic patients we estimated the following risk ratios (95% credible intervals): moderate versus low 3.5 (2.4, 5.1) and high versus low 9.9 (5.3, 17.6). Similar results were obtained for studies of symptomatic patients. Ratios comparing the risk of no CAD among symptomatic patients were as follows: moderate versus low 0.5 (0.3, 0.8) and high versus low 0.12 (0.05, 0.2).

Conclusion: Increasing EBCT scores indicate higher risk for CAD in both asymptomatic and symptomatic patients. In general, asymptomatic patients with EBCT scores in the high category can perhaps be considered for preventive medical therapy and risk factor modification. Symptomatic patients with EBCT scores in the low category can perhaps, at least temporarily, avoid invasive coronary angiography. However, the non-uniform quality of studies and the lack of availability of individual-level data preclude the extension of our results to individual patients.

Show MeSH
Related in: MedlinePlus