Editor's Choice - Metformin Prescription is Associated with a Reduction in the Combined Incidence of Surgical Repair and Rupture Related Mortality in Patients with Abdominal Aortic Aneurysm

Jonathan Golledge; Dylan R Morris; Jenna Pinchbeck; Sophie Rowbotham; Jason Jenkins; Michael Bourke; Bernard Bourke; Paul E Norman; Rhonda Jones; Joseph V Moxon

doi:10.1016/j.ejvs.2018.07.035

Editor's Choice - Metformin Prescription is Associated with a Reduction in the Combined Incidence of Surgical Repair and Rupture Related Mortality in Patients with Abdominal Aortic Aneurysm

Eur J Vasc Endovasc Surg. 2019 Jan;57(1):94-101. doi: 10.1016/j.ejvs.2018.07.035. Epub 2018 Aug 30.

Authors

Affiliations

¹ Queensland Research Centre for Peripheral Vascular Disease, College of Medicine and Dentistry, James Cook University, Townsville, Queensland, Australia; The Department of Vascular and Endovascular Surgery, The Townsville Hospital, Townsville, Queensland, Australia; The Australian Institute of Tropical Health and Medicine, James Cook University, Townsville, Queensland, Australia. Electronic address: Jonathan.Golledge@jcu.edu.au.
² Queensland Research Centre for Peripheral Vascular Disease, College of Medicine and Dentistry, James Cook University, Townsville, Queensland, Australia.
³ Queensland Research Centre for Peripheral Vascular Disease, College of Medicine and Dentistry, James Cook University, Townsville, Queensland, Australia; School of Medicine, University of Queensland, Brisbane, Queensland, Australia; Royal Brisbane and Women's Hospital, Herston, Queensland, Australia.
⁴ Royal Brisbane and Women's Hospital, Herston, Queensland, Australia.
⁵ Queensland Research Centre for Peripheral Vascular Disease, College of Medicine and Dentistry, James Cook University, Townsville, Queensland, Australia; Gosford Vascular Clinic, Gosford, New South Wales, Australia.
⁶ Gosford Vascular Clinic, Gosford, New South Wales, Australia.
⁷ Medical School, University of Western Australia, Perth, Western Australia, Australia.
⁸ Queensland Research Centre for Peripheral Vascular Disease, College of Medicine and Dentistry, James Cook University, Townsville, Queensland, Australia; The Department of Vascular and Endovascular Surgery, The Townsville Hospital, Townsville, Queensland, Australia.
⁹ Queensland Research Centre for Peripheral Vascular Disease, College of Medicine and Dentistry, James Cook University, Townsville, Queensland, Australia; The Australian Institute of Tropical Health and Medicine, James Cook University, Townsville, Queensland, Australia.

PMID: 30174271
DOI: 10.1016/j.ejvs.2018.07.035

Abstract

Objectives: Currently there is no drug therapy for abdominal aortic aneurysm (AAA) and most previous investigations have focused on imaging rather than clinical outcomes. The aim of this study was to assess whether AAA related clinical events were lower in patients prescribed metformin.

Methods: This was a prospective cohort observational study performed in three cities in Australia, which was designed to study risk factors for clinical events not simply to focus on metformin. Patients with an asymptomatic unrepaired AAA of any diameter ≥30 mm were recruited from hospital outpatient clinics and surveillance programs run at four centres. The main outcome was the requirement for AAA repair or AAA related mortality (AAA events). The association between metformin prescription and AAA events was assessed using Kaplan-Meier analysis and Cox proportional hazard analysis.

Results: Patients (1,080) with a mean (SD) initial AAA diameter of 46.1 (11.3) mm were followed for a mean (SD) of 2.5 (3.1) years until an AAA event (n = 454), death (n = 176), loss to follow up (n = 128), or completion of current follow up (n = 322). Patients with diabetes who were prescribed metformin (adjusted HR 0.63, 95% CI 0.44-0.93), but not patients with diabetes who were not prescribed metformin (adjusted HR 1.15, 95% CI 0.83-1.59), had a lower incidence of AAA events compared with those without diabetes. Findings were similar in sensitivity analyses restricted to patients with an initial AAA diameter ≤50 mm and patients with a minimum follow up of six months before an AAA event.

Conclusions: These findings suggest that clinically important AAA events may be reduced in patients with diabetes who are prescribed metformin, but not those with diabetes receiving other treatments. A randomised controlled trial is needed to definitively test whether metformin reduces AAA related clinical events in patients with small AAAs who do not have diabetes.

Keywords: Abdominal aortic aneurysm; Metformin; Surgical repair.

Publication types

Observational Study

MeSH terms

Aged
Aged, 80 and over
Aortic Aneurysm, Abdominal / epidemiology*
Aortic Aneurysm, Abdominal / mortality
Aortic Aneurysm, Abdominal / surgery
Aortic Rupture / epidemiology*
Aortic Rupture / mortality
Aortic Rupture / surgery
Australia / epidemiology
Cohort Studies
Cost-Benefit Analysis
Diabetes Mellitus / drug therapy*
Drug Prescriptions
Endovascular Procedures / methods
Endovascular Procedures / statistics & numerical data*
Female
Humans
Incidence
Kaplan-Meier Estimate
Male
Metformin / administration & dosage*
Metformin / therapeutic use
Prospective Studies
Risk Factors

Substances

Metformin