Cardiopulmonary MedicineOriginal ArticleCME

Abnormal vascular physiology in the lower extremities as a risk factor for ischemic stroke and mortality

Shubhang K. Bhatt, BS; Andrew S. Tseng, MD; Christine Firth, MD; Marlene Girardo, MS; Daniel Sykora, BA; Mina Abdelmalek, MD; F. David Fortuin, MD; Paul Wennberg, MD; David Liedl, RN; and Fadi E. Shamoun, MD
Notes and Affiliations
Notes and Affiliations

Received: November 9, 2020

Accepted: December 22, 2020

Published: March 10, 2021

  • Shubhang K. Bhatt, BS, 

    Mayo Clinic Alix School of Medicine, Scottsdale, AZ, USA

  • Andrew S. Tseng, MD, 

    Department of Cardiovascular Diseases at the Mayo Clinic, Rochester, MN, USA

  • Christine Firth, MD, 

    Department of Cardiovascular Diseases at the Mayo Clinic, Phoenix, AZ, USA

  • Marlene Girardo, MS, 

    Department of Biomedical Statistics and Informatics, Division of Health Sciences Research at the Mayo Clinic, Scottsdale, AZ, USA

  • Daniel Sykora, BA, 

    Mayo Clinic Alix School of Medicine, Scottsdale, AZ, USA

  • Mina Abdelmalek, MD, 

    Department of Cardiovascular Diseases at the Mayo Clinic, Phoenix, AZ, USA

  • F. David Fortuin, MD, 

    Department of Cardiovascular Diseases at the Mayo Clinic, Phoenix, AZ, USA

  • Paul Wennberg, MD, 

    Department of Cardiovascular Diseases at the Mayo Clinic, Rochester, MN, USA

  • David Liedl, RN, 

    Department of Cardiovascular Diseases at the Mayo Clinic, Rochester, MN, USA

  • Fadi E. Shamoun, MD, 

    Department of Cardiovascular Diseases at the Mayo Clinic, Phoenix, AZ, USA

J Osteopath Med; 121(5): 463-470
Abstract

Context: Peripheral artery disease (PAD) is highly prevalent in the general population, affecting up to 25% of patients 55 years of age or older. There is a known association with acute ischemic stroke, but limited large cohort studies exist pertaining to the relationship between PAD severity and incident ischemic stroke.

Objectives: To evaluate the risk of incident ischemic stroke and mortality along the spectrum of low and elevated ankle brachial index (ABI) measurement.

Methods: We performed a retrospective extraction of ABI data of all adult patients who underwent lower extremity physiology study for any indication from January 1, 1996 to June 30, 2018 in the Mayo Clinic health system. PAD was categorized into severe, moderate, mild, and borderline based on ABI measurements and poorly compressible arteries (PCA). These were compared with normal ABI measurements. Associations of PAD/PCA with new ischemic stroke events and all-cause mortality were analyzed. Hazard ratios (HR) were calculated using multivariable Cox proportional regression with 95% confidence intervals.

Results: A total of 39,834 unique patients were included with a median follow up duration of 4.59 years. All abnormal ABI groups, except borderline PAD, were associated with increased risk of incident ischemic stroke after multivariate regression compared to normal ABI. A severity-dependent association was observed between PAD and ischemic stroke with moderate (HR, 1.22 [95% CI, 1.10–1.35]) and severe (HR, 1.19 [95% CI, 1.02–1.40]) categories conferring similar risk in comparison to normal ABI. Patients with PCA carried the greatest ischemic stroke risk (HR, 1.30 [95% CI, 1.15–1.46]). Similarly, abnormal ABI groups were associated with a significant risk for all-cause mortality in a severity-dependent manner, with severe PAD conferring the greatest risk (HR, 3.07 [95% CI, 2.88–3.27]).

Conclusions: This study adds to the growing body of evidence that both PAD and PCA are independent risk factors for incident ischemic stroke and all-cause mortality. The association of PAD severity and PCA with risk of ischemic stroke may help clinicians with risk stratification and determining treatment intensity.

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