Comparison of resting/postexercise ankle-brachial index and transcutaneous partial pressure of oxygen for noninvasive diagnosis of peripheral artery disease in type 2 diabetes mellitus

Ravikumar Dinesh; Kolar Vishwanath Vinod; Govindarajalou Ramkumar

doi:10.1016/j.mjafi.2020.11.002

Comparison of resting/postexercise ankle-brachial index and transcutaneous partial pressure of oxygen for noninvasive diagnosis of peripheral artery disease in type 2 diabetes mellitus

Med J Armed Forces India. 2023 Mar-Apr;79(2):157-164. doi: 10.1016/j.mjafi.2020.11.002. Epub 2021 Apr 2.

Authors

Ravikumar Dinesh¹, Kolar Vishwanath Vinod², Govindarajalou Ramkumar³

Affiliations

¹ Junior Resident (General Medicine), Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry, India.
² Additional Professor (Medicine), Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry, India.
³ Associate Professor (Radiodiagnosis), Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry, India.

Abstract

Background type 2 diabetes: Type 2 diabetes mellitus (T2DM) is a strong risk factor for peripheral artery disease (PAD) and PAD diagnosis in T2DM may indicate coexisting coronary artery disease as well. Postexercise ankle brachial index (ABI) and transcutaneous partial pressure of oxygen (TcPO₂) have not been evaluated for PAD diagnosis among Indian T2DM patients. This study aimed to evaluate the performance of resting + postexercise(R + PE) ABI and R + PE-TcPO₂ for PAD diagnosis among T2DM patients at increased PAD risk, using colour duplex ultrasound (CDU) as reference standard.

Methods: This prospectively conducted diagnostic accuracy study involved T2DM patients at increased PAD risk. R-ABI≤0.9 or PE-ABI decline >20% from resting value in those with R-ABI between 0.91 and 1.4, R-TcPO₂ <30 mm Hg or PE decline of TcPO₂ to <30 mm Hg in those with R-TcPO₂ ≥30 mm Hg, CDU showing >50% stenosis or complete occlusion of lower extremity arteries constituted PAD.

Results: Among 168 patients enrolled, R + PE-ABI diagnosed PAD in 19(11.3%), R + PE-TcPO₂ in 61 (36.3%) and 17 (≈10%) had PAD finally confirmed by CDU. Sensitivity, specificity, PPV and NPV of R + PE-ABI for PAD diagnosis were 82.3%, 96.7%, 73.7% and 98% and that of R + PE-TcPO₂ were 76.5%, 68.2%, 21.3% and 96.2%, respectively. PE-ABI increased the sensitivity of ABI by ≈ 18% and had 100% PPV for PAD. When both ABI and TcPO₂ (R + PE tests) were normal, PAD could be safely excluded in 88% of patients.

Conclusion: PE-ABI should be routinely employed and TcPO₂(R/PE) is unreliable as a stand-alone test for PAD detection among moderate to high risk T2DM patients.

Keywords: Ankle brachial index; Peripheral artery disease; Post-exercise test; Transcutaneous partial pressure of oxygen; Type 2 diabetes.