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Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews [Internet]. York (UK): Centre for Reviews and Dissemination (UK); 1995-.

Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews [Internet].

Meta-analysis: accuracy of contrast-enhanced magnetic resonance angiography for assessing steno-occlusions in peripheral arterial disease

J Menke and J Larsen.

Review published: 2010.

Link to full article: [Journal publisher]

CRD summary

This generally well-conducted review concluded that magnetic resonance angiography had high accuracy for identifying or excluding clinically relevant arterial stenosis or occlusion in adults with symptomatic peripheral artery disease. Despite some limitations of the available evidence, the conclusion of the review is likely to be reliable.

Authors' objectives

To assess the accuracy of magnetic resonance angiography (MRA) in identifying arterial stenosis or occlusions in adults with symptoms of peripheral artery disease.

Searching

PubMed, Scopus, BIOSIS Previews and Web of Science were searched without language restrictions from January 1998 to December 2009; search terms were reported. References of retrieved articles were also searched.

Study selection

Prospective studies with at least 10 adults with known or suspected peripheral artery disease, using gadolinium chelate-enhanced MRA to identify 50% or greater stenosis or occlusion of the arteries of the lower extremities, compared with intra-arterial digital subtraction angiography, were eligible for inclusion. Studies had to report sufficient data to construct 2x2 tables of test performance.

Most patients had symptomatic peripheral artery disease; an average of 26% (range 0 to 100%) had critical limb ischaemia. Between 46% and 90% of patients were male (where reported); mean age ranged from 58 to 82 years. Most studies used MRA with a 1.5 Tesla magnet. The dose of gadolinium ranged from 0.1 to 0.3mmol/kg per injection; some patients had two or three injections. The number of segments per patient ranged from five to 31.

Two independent reviewers selected studies for inclusion; disagreements were resolved by consensus.

Assessment of study quality

Study quality was assessed using the 14-criteria QUADAS (Quality Assessment of Diagnostic Accuracy Studies) tool. Each item was scored 1 point if fulfilled, 0.5 if unclear, and 0 points if unfulfilled; a score of 11 or over was considered to indicate high quality.

It seemed that at least two reviewers performed the quality assessment.

Data extraction

Data were extracted by two independent reviewers to construct 2x2 (non-diseased with less than 50% stenosis and diseased with 50 to 100% stenosis) or 3x3 (non-diseased, 50% to 99% stenosis, and occlusion with 100% stenosis) tables of test performance on a per-segment basis, for the entire arterial tree and three arterial subsections (where possible). Sensitivities and specificities were calculated from the 2x2 tables. Study investigators were contacted to clarify the direction of data collection and method of recruitment. Disagreements were resolved by consensus.

Methods of synthesis

Pooled estimates for sensitivity and specificity with 95% confidence intervals (CI) were calculated using a bivariate random-effects meta-analysis; from these, estimates of positive and negative likelihood ratios (LR+ and LR-) were calculated. Heterogeneity was assessed using the Cochrane Q and I2 statistics. A bivariate random-effects meta-regression was used to investigate the impact of study size and quality, patient characteristics, and MRA protocol. Data from the 3x3 tables were pooled using a multivariate fixed-effect meta-analysis.

Publication bias was assessed using a funnel plot and meta-regression of the log diagnostic odds ratio versus the sample size; the regression slope was tested for positivity.

Results of the review

Thirty-two studies met the inclusion criteria (n=1,022 patients; range 10 to 76). Study quality was considered to be generally high; the median QUADAS score was 13 (range 11.5 to 14). Two studies avoided clinical review bias. Twenty-eight studies reported recruiting a consecutive sample. The proportion of excluded (uninterpretable) segments from 0 to 13%. There was no evidence of publication bias.

Entire arterial tree (19 studies): Magnetic resonance angiography (MRA) pooled sensitivity was 94.7% (95% CI 92.1 to 96.4); specificity was 95.6% (95% CI 94.0 to 96.8); positive likelihood ratio was 21.56 (95% CI 15.70 to 29.69); and negative likelihood ratio was 0.056 (95% CI 0.037 to 0.083). Heterogeneity was high for both sensitivity (I2=81%) and specificity (I2=89%). There was no evidence of publication bias.

Aortoiliac subregion (19 studies): MRA pooled sensitivity was 93.5% (95% CI 90.51 to 95.64); specificity was 96.3% (95% CI 94.5 to 97.6); positive likelihood ratio was 25.33 (95% CI 16.80 to 38.41); and negative likelihood ratio was 0.067 (95% CI 0.045 to 0.099).

Femoropopliteal subregion (20 studies): MRA pooled sensitivity was 95.3% (95% CI 90.6 to 97.7); specificity was 95.6% (95% CI 93.9 to 96.8); positive likelihood ratio was 21.40 (95% CI 15.26 to 29.81); negative likelihood ratio was 0.050 (95% CI 0.024 to 0.099).

Tibiofibular subregion (25 studies): MRA pooled sensitivity was 92.2% (95% CI 89.5 to 96.4); specificity was 93.3% (95% CI 89.8 to 95.7); positive likelihood ratio was 13.80 (95% CI 8.95 to 21.53); and negative likelihood ratio was 0.083 (95% CI 0.060 to 0.114).

Analysis of the 3x3 data showed 95.3% of arterial segments were correctly staged/classified, 3.1% were overstaged, and 1.6% were understaged.

Results of several subgroup analyses were reported.

Authors' conclusions

MRA had high accuracy for identifying or excluding clinically relevant arterial stenosis or occlusion in adults with symptomatic peripheral artery disease.

CRD commentary

The review addressed a clear review question, supported by well-defined inclusion criteria. Several relevant databases were searched without language restrictions, but there was no specific search for unpublished studies, so some relevant data may have been missed. Each stage of the review process seemed to be conducted in duplicate, reducing the risk of error and bias.

Study quality was assessed using appropriate criteria; the results for each criterion for each study were reported and the impact of study quality was investigated. There was a large degree of inconsistency across studies for the entire arterial tree; results of the tests for heterogeneity were not reported for the analyses of arterial subregions. There was considerable clinical heterogeneity across studies, in terms of the number of segments assessed, severity of disease, and the MRA protocol employed. Therefore, the reliability and generalisability of the pooled estimates are uncertain. Despite this, the proportion of studies with sensitivity and/or specificity over 90% was: 79% (sensitivity) and 88% (specificity) for the entire arterial tree and the aortoiliac subregion; the proportion was lower for the other subregions. In addition, several potential sources of heterogeneity were investigated and the quality of the included studies was high.

The conclusion of this generally well-conducted review was supported by the evidence and is likely to be reliable.

Implications of the review for practice and research

Practice: The authors stated that: the general use of the bolus-chase method of image acquisition, and the hybrid technique only in cases with relevant venous overlay, is justified; and there was no evidence that high total dose of gadolinium (0.24 to 0.30mmol/kg) performed better lower total dose (0.20 to 0.23mmol/kg).

Research: The authors did not state implications for research.

Funding

None.

Bibliographic details

Menke J, Larsen J. Meta-analysis: accuracy of contrast-enhanced magnetic resonance angiography for assessing steno-occlusions in peripheral arterial disease. Annals of Internal Medicine 2010; 153(5): 325-334. [PubMed: 20820041]

Indexing Status

Subject indexing assigned by NLM

MeSH

Arterial Occlusive Diseases /diagnosis /etiology; Contrast Media; Humans; Leg /blood supply; Magnetic Resonance Angiography /methods; Peripheral Vascular Diseases /complications /diagnosis; Research Design /standards; Sensitivity and Specificity

AccessionNumber

12010005958

Database entry date

22/09/2010

Record Status

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.

CRD has determined that this article meets the DARE scientific quality criteria for a systematic review.

Copyright © 2014 University of York.

PMID: 20820041

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