Effectiveness of Four‐Limb Blood Pressure in Distinguishing Between Aortic Stenosis and Bilateral Lower‐Extremity Arterial Stenosis

Figures

• 

  FIGURE 1. Flowchart of the study procedure. Pts, patients.

• 

  FIGURE 2. Comparison of ABI among the AS, BLEAS, and control groups. The ABI was normal in the control group, whereas the ABI decreased bilaterally in the AS and BLEAS groups. The ∆ABI in the BLEAS group was higher than that in the AS (p < 0.001) and control (p < 0.001) groups, which were not significantly different (p = 0.631). ABI, ankle–brachial index; AS, aortic stenosis; BLEAS, bilateral lower‐extremity arterial stenosis.

• 

  FIGURE 3. Comparison of BAI among the AS, BLEAS, and control groups. The BAI was normal in the control group but elevated bilaterally in the AS and BLEAS groups. The L‐BAI in the BLEAS (p < 0.001) and AS (p < 0.001) groups was comparable (p = 0.553) and higher than that in the control group. AS, aortic stenosis; BAI, brachial–ankle index; BLEAS, bilateral lower‐extremity arterial stenosis.

• 

  FIGURE 4. Comparison of ABI among different degrees of AS. When the degree of AS ranged from 50% to 69%, the ABI was generally normal; however, when it increased to ≥70%, the ABI decreased proportionally. ABI, ankle–brachial index; AS, aortic stenosis.

• 

  FIGURE 5. Comparison of BAI among different degrees of AS. When the degree of AS ranged from 50% to 69%, the BAI was generally normal; however, as it increased to ≥70%, the BAI increased proportionately. AS, aortic stenosis; BAI, brachial–ankle index.

• 

  FIGURE 6. ROC curves were plotted to determine the optimal cutoffs for differentiating between AS and BLEAS. When using bilateral ABI ≤0.90 for AS screening, the AUC was 0.784 (95% CI: 0.755–0.812), providing a sensitivity and specificity of 85.3% and 74.8%. When using a combination of bilateral ABI ≤0.90, ∆ABI ≤0.10, and L‐BAI >1.00 for AS screening, the AUC was 0.873 (95% CI: 0.839–0.908), with a Youden index of 0.724. This combination of indicators demonstrated a sensitivity and specificity of 85.2% and 87.2%, respectively. The DeLong test was used to compare the performance of two ROC curves. The results showed that the performance of screening for AS using the combination of “bilateral ABI ≤0.90, ∆ABI ≤0.10, and L‐BAI >1.00” was significantly higher than that using “bilateral ABI ≤0.90” alone (p = 0.001), with an AUC difference of 0.040 (95% CI: 0.017–0.064). ∆ABI, the absolute value of the left ABI minus the right ABI; ABI, ankle–brachial index; AS, aortic stenosis; BAI, brachial–ankle index; BLEAS, bilateral lower‐extremity arterial stenosis; L‐BAI, the side with the lowest BAI; ROC, receiver operating characteristic.