Correlations Between Peripheral Artery Disease and Cardiovascular Disease Outcomes

  • Author / Creator
    Sebastianski, Meghan K
  • Lower-extremity peripheral artery disease (PAD) is a manifestation of atherosclerotic disease in the lower limbs. PAD is a risk factor for poor outcomes including myocardial infarction, stroke, and mortality. Despite the potential benefits of early PAD detection, in the majority of PAD cases patients are asymptomatic, and as a result, PAD is underdiagnosed and undertreated. Furthermore, additional evidence is needed to clarify if PAD prevalence varies between ethnic groups. In short, the true burden of PAD is unknown.

    The main objective was to explore the prognostic relationship between PAD and outcomes in patients undergoing coronary angiography. Prospective collection of an ankle-brachial index (ABI), a non-invasive test with a high sensitivity and specificity for detecting PAD, was undertaken in 1100 patients. As ABI is often dichotomized for use in PAD detection and risk stratification, we examined continuous ABI as a risk marker and predictor of outcomes. We also undertook a systematic review of PAD prevalence studies and a cross-sectional analysis of cohort data to investigate the ethnic burden of PAD.

    Patients undergoing coronary angiography who have PAD (ABI ≤ 0.90) had 4.3 times more complex coronary artery disease (CAD) (adjusted OR 4.3, 95% CI 1.2, 14.9; p=0.022), 3.5 times more myocardium at risk (adjusted OR 3.5, 95% CI 1.7, 7.1; p=0.001), and less complete coronary revascularization (adjusted OR 3.0, 95% CI 1.1, 8.8; p=0.039) than patients with a normal ABI. At the other end of the ABI spectrum, there was no positive association between ABI > 1.40 and systolic inter-arm blood pressure difference (IAD) ≥ 10mmHg; rather there was a trend for a negative association (adjusted OR 0.3, 95% CI 0.1, 1.3; p=0.117).

    Differences in PAD prevalence were found in our systematic review where South Asians had significantly less PAD than White Europeans. Interestingly, no differences in PAD prevalence were found across six ethnic groups of patients undergoing hemodialysis.

    Our results support ABI use in screening and risk prediction in patients undergoing coronary angiography. More evidence is needed to determine the mechanisms for ethnic differences in PAD prevalence and further discussion of ABI is necessary to develop population appropriate guidelines.

  • Subjects / Keywords
  • Graduation date
    Spring 2014
  • Type of Item
  • Degree
    Doctor of Philosophy
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.