Walking and Ankle-Brachial Index Assessments in PAD
Background. The relationship of peripheral arterial mean translesional pressure gradient (TLG) to presenting symptom, functional impairment, and initial noninvasive ABI assessments has never been established. Objectives. To evaluate the association between TLG, severity of walking impairment, rest and exercise ankle-brachial indices (ABI). Methods. TLG in 19 patients presenting with claudication and single superficial femoral artery lesion were measured invasively. TLG was measured at rest and post-hyperemia induction with intra-arterial adenosine (100 and 200 μg), nitroglycerin (100 and 200 μg), and after 3 minutes of ipsilateral calf cuff pressure inflation-deflation sequence. For each patient, a walking impairment questionnaire (WIQ) was completed and rest and exercise ABI were measured prior to TLG assessment. Results. Mean age was 60 ± 6 years, 89% were men. Mean WIQ score was 4817 ± 3549, mean rest and exercise ABI were 0.79 ± 0.14 and 0.59 ± 0.17, respectively, and mean exercise duration was 6.3 ± 3.4 minutes. TLG with 100 μg of adenosine strongly correlates with WIQ score (r = -0.723); rest ABI (r = -0.748); exercise ABI (r = -0.888), exercise duration (r = -0.711), and percent angiographic stenosis (r = -0.818), respectively (p < 0.01 for all). TLG with adenosine 200 μg, nitroglycerin 100 and 200 μg and after cuff inflation-deflation also demonstrated significant correlation. Receiver operator curve analysis demonstrated that a TLG ≥ 11 mmHg post 100 μg adenosine administration had 71.43% sensitivity and 100% specificity for identifying patients with disease defining state of exercise ABI ≤ 0.70. Conclusion. This study validates the utility of invasive TLG measurements using vasodilation for determining the functional and hemodynamic significance of superficial femoral artery lesions.
Peripheral arterial disease (PAD) affects more than 30 million Americans and is a leading cause of cardiovascular morbidity, mortality, and socio-economic burden due to functional impairments and limb amputations. Though there have been significant strides in the diagnosis and treatment of PAD, there currently are no studies that provide invasive hemodynamic correlates of PAD symptoms and traditional screening tests such as the ankle-brachial index (ABI). Establishing these correlates along with discriminating thresholds for PAD disease state may help clinicians not only in the invasive assessment of patients with claudication or pseudoclaudication, but also in the evaluation of angiographically intermediate lesions, selection of endovascular treatment targets, along with success and durability of therapy.
To the best of our knowledge, this study is the first to report correlation of invasive infra-inguinal peripheral arterial mean translesional mean pressure gradients (TLG) with subjective [walking impairment questionnaire (WIQ)] and objective (rest and exercise ABI and exercise duration) measures of lower extremity claudication.
Abstract and Introduction
Abstract
Background. The relationship of peripheral arterial mean translesional pressure gradient (TLG) to presenting symptom, functional impairment, and initial noninvasive ABI assessments has never been established. Objectives. To evaluate the association between TLG, severity of walking impairment, rest and exercise ankle-brachial indices (ABI). Methods. TLG in 19 patients presenting with claudication and single superficial femoral artery lesion were measured invasively. TLG was measured at rest and post-hyperemia induction with intra-arterial adenosine (100 and 200 μg), nitroglycerin (100 and 200 μg), and after 3 minutes of ipsilateral calf cuff pressure inflation-deflation sequence. For each patient, a walking impairment questionnaire (WIQ) was completed and rest and exercise ABI were measured prior to TLG assessment. Results. Mean age was 60 ± 6 years, 89% were men. Mean WIQ score was 4817 ± 3549, mean rest and exercise ABI were 0.79 ± 0.14 and 0.59 ± 0.17, respectively, and mean exercise duration was 6.3 ± 3.4 minutes. TLG with 100 μg of adenosine strongly correlates with WIQ score (r = -0.723); rest ABI (r = -0.748); exercise ABI (r = -0.888), exercise duration (r = -0.711), and percent angiographic stenosis (r = -0.818), respectively (p < 0.01 for all). TLG with adenosine 200 μg, nitroglycerin 100 and 200 μg and after cuff inflation-deflation also demonstrated significant correlation. Receiver operator curve analysis demonstrated that a TLG ≥ 11 mmHg post 100 μg adenosine administration had 71.43% sensitivity and 100% specificity for identifying patients with disease defining state of exercise ABI ≤ 0.70. Conclusion. This study validates the utility of invasive TLG measurements using vasodilation for determining the functional and hemodynamic significance of superficial femoral artery lesions.
Introduction
Peripheral arterial disease (PAD) affects more than 30 million Americans and is a leading cause of cardiovascular morbidity, mortality, and socio-economic burden due to functional impairments and limb amputations. Though there have been significant strides in the diagnosis and treatment of PAD, there currently are no studies that provide invasive hemodynamic correlates of PAD symptoms and traditional screening tests such as the ankle-brachial index (ABI). Establishing these correlates along with discriminating thresholds for PAD disease state may help clinicians not only in the invasive assessment of patients with claudication or pseudoclaudication, but also in the evaluation of angiographically intermediate lesions, selection of endovascular treatment targets, along with success and durability of therapy.
To the best of our knowledge, this study is the first to report correlation of invasive infra-inguinal peripheral arterial mean translesional mean pressure gradients (TLG) with subjective [walking impairment questionnaire (WIQ)] and objective (rest and exercise ABI and exercise duration) measures of lower extremity claudication.