Rosemarie Met

Diagnostic Performance of Computed Tomography Angiography in Peripheral Arterial Disease: A Systematic Review and Meta-analysis

CONTEXT Computed tomography angiography (CTA) is an increasingly attractive imaging modality for assessing lower extremity peripheral arterial disease (PAD). OBJECTIVE To determine the accuracy of CTA compared with intra-arterial digital subtraction angiography (DSA) in differentiating extent of disease in patients with PAD. DATA SOURCES AND STUDY SELECTION Search of MEDLINE (January 1966-August 2008), EMBASE (January 1980-August 2008), and the Database of Abstracts of Reviews of Effectiveness for studies comparing CTA with intra-arterial DSA for PAD. Eligible studies compared multidetector CTA with intra-arterial DSA, included at least 10 patients with intermittent claudication or critical limb ischemia, aimed to detect more than 50% stenosis or arterial occlusion, and presented either 2 x 2 or 3 x 3 contingency tables (< or = 50% stenosis vs > 50% stenosis or occlusion), or provided data allowing their construction. DATA EXTRACTION Two reviewers screened potential studies for inclusion and independently extracted study data. Methodological quality was assessed by using the QUADAS instrument. DATA SYNTHESIS Of 909 studies identified, 20 (2.2%) met the inclusion criteria. These 20 studies had a median sample size of 33 (range, 16-279) and included 957 patients, predominantly with intermittent claudication (68%). Methodological quality was moderate. Overall, the sensitivity of CTA for detecting more than 50% stenosis or occlusion was 95% (95% confidence interval [CI], 92%-97%) and specificity was 96% (95% CI, 93%-97%). Computed tomography angiography correctly identified occlusions in 94% of segments, the presence of more than 50% stenosis in 87% of segments, and absence of significant stenosis in 96% of segments. Overstaging occurred in 8% of segments and understaging in 15%. CONCLUSION Computed tomography angiography is an accurate modality to assess presence and extent of PAD in patients with intermittent claudication; however, methodological weaknesses of examined studies prevent definitive conclusions from these data.

The AMC Linear Disability Score (ALDS): a cross-sectional study with a new generic instrument to measure disability applied to patients with peripheral arterial disease

BackgroundThe AMC Linear Disability Score (ALDS) is a calibrated generic itembank to measure the level of physical disability in patients with chronic diseases. The ALDS has already been validated in different patient populations suffering from chronic diseases. The aim of this study was to assess the clinimetric properties of the ALDS in patients with peripheral arterial disease.MethodsPatients with intermittent claudication (IC) and critical limb ischemia (CLI) presenting from January 2007 through November 2007 were included. Risk factors for atherosclerosis, ankle/brachial index and toe pressure, the Vascular Quality of Life Questionnaire (VascuQol), and the ALDS were recorded. To compare ALDS and VascuQol scores between the two patient groups, an unpaired t-test was used. Correlations were determined between VascuQol, ALDS and pressure measurements.ResultsSixty-two patients were included (44 male, mean ± sd age was 68 ± 11 years) with IC (n = 26) and CLI (n = 36). The average ALDS was significantly higher in patients with IC (80, ± 10) compared to patients with CLI (64, ± 18). Internal reliability consistency of the ALDS expressed as Cronbachs α coefficient was excellent (α > 0.90). There was a strong convergent correlation between the ALDS and the disability related Activity domain of the VascuQol (r = 0.64).ConclusionThe ALDS is a promising clinimetric instrument to measure disability in patients with various stages of peripheral arterial disease.

Statistical or clinical improvement? Determining the minimally important difference for the vascular quality of life questionnaire in patients with critical limb ischemia.

OBJECTIVE Interpreting whether changes in quality of life (Qol) in patients with peripheral arterial disease (PAD) are not only statistically significant but also clinically relevant, may be difficult. This study introduces the concept of the minimally important difference (MID) to vascular surgeons using Qol outcomes of patients treated for chronic critical limb ischemia (CLI). METHODS The Vascular Quality of Life (VascuQol) questionnaire was recorded at baseline before treatment and after 6 months follow-up in consecutive patients with CLI treated between May 2007 and May 2010. Statistical significance of change in VascuQol score was tested with the Wilcoxon Signed Rank test. The MID for the VascuQol score was determined using a clinical anchor-based method and a distribution-based method. RESULTS A total of 127 patients with CLI completed the VascuQol after 6 months. The VascuQol sum scores improved from 3.0 (range 1.1-5.9) at baseline to 4.0 (range 1.2-6.7) at 6 months (p < .001). The MID on the VascuQol sumscore indicating a clinically important change determined with the anchor-based method was 0.36, and with the distribution-based method was 0.48. On an individual level, depending on the method of determining the MID, this resulted in 60% to 68% of the patients with an important benefit. CONCLUSIONS Expression of changes in Qol by means of the MID provides better insight into clinically important changes than statistical significance.

Changes in functional status after treatment of critical limb ischemia

OBJECTIVE This study evaluated changes in functional status with the Academic Medical Center Linear Disability Score (ALDS) and in quality of life with the Vascular Quality of Life Questionnaire (VascuQol) in patients treated for critical limb ischemia (CLI). METHODS We conducted a prospective observational cohort study in a single academic center that included consecutive patients with CLI who presented between May 2007 and May 2010. The ALDS and VascuQol questionnaires were administered before treatment (baseline) and after treatment at 6 and 12 months of follow-up. Changes in functional status (ALDS) and quality of life (VascuQol) scores after 6 and 12 months, compared with baseline, were tested with the appropriate statistical tests, with significance set at P < .05. RESULTS The study included 150 patients, 96 (64%) were men, and mean (± standard deviation) age was 68.1 (± 12.4) years. The primary treatment was endovascular in 98 (65.3%), surgical in 36 (24%), conservative in 11 (7.3%), or a major amputation in five (3.3%). The ALDS was completed by 112 patients after 12 months. At that time, the median ALDS score had increased by 10 points (median, 83; range, 12-89; P = .001) in patients who achieved limb salvage, which corresponds with more difficult outdoor and indoor activities. In patients with a major amputation, the median ALDS score decreased by 14 points (median, 55; range, 16-89; P = .117) after 12 months, which corresponds with domestic activities only. VascuQol scores improved significantly in all separate domains for the limb salvage group (P < .001). All VascuQol scores, except for the activity and social domains, increased significantly after amputation. CONCLUSIONS Our study confirms the clinical validity of the ALDS in patients treated for CLI and shows that it is a valuable and sophisticated instrument to measure changes in functional status in these patients.