What question did this study set out to answer?

This analysis aims to compare the effectiveness of various medical therapies in reducing subthreshold abdominal aortic aneurysm growth and mortality rates.

March 26, 2026Open Access

The effect of medical therapies for subthreshold abdominal aortic aneurysm growth and mortality: a network meta-analysis of randomized controlled trials

Key Result

Medical therapies did not reduce subthreshold abdominal aortic aneurysm growth or mortality, while propranolol (OR 3.14) and ticagrelor (OR 5.10) increased adverse event discontinuations.

Key Points

This analysis aims to compare the effectiveness of various medical therapies in reducing subthreshold abdominal aortic aneurysm growth and mortality rates.
Conducted a network meta-analysis of randomized controlled trials
Searched MEDLINE, Scopus, Web of Science, EBSCO, and Cochrane Library for relevant studies
Assessed outcomes like AAA growth rate and overall mortality across treatments
Analyzed data with R software and ranked treatments using P-scores
Thirteen trials with 3084 patients were included
No significant differences in AAA growth rates between treatment groups
Propranolol and ticagrelor had higher rates of treatment discontinuation due to adverse events
Most studies provided moderate quality evidence on treatment efficacy

Structured PICO

Do medical therapies reduce AAA growth rate and mortality in patients with subthreshold abdominal aortic aneurysms?

Population

Patients with subthreshold abdominal aortic aneurysms (AAA)

Intervention

Medical therapies including propranolol, telmisartan, antibiotics, ACE inhibitors, ticagrelor, and pemirolast

Comparator

Placebo

Outcome

AAA growth ratesurrogate

Current medical therapies do not significantly reduce subthreshold AAA growth, surgery referral, or mortality compared to placebo, highlighting the lack of proven pharmacological treatments to halt AAA progression.

Main Result

Absolute Event Rate: 0% vs 0%

Abstract

Abstract OBJECTIVES Abdominal aortic aneurysm (AAA) is often fatal when ruptured and current guidelines suggest surgical management at suprathreshold sizes (50 mm for women or 55 mm for men) or with rapid expansion (5 mm/year). Many medical therapies have been assessed for reducing subthreshold AAA expansion though the evidence remains inconclusive. This network meta-analysis (NMA) compares AAA growth and mortality amongst medical treatments for AAAs. METHODS MEDLINE (via PubMed), Scopus, Web of Science, EBSCO, and Cochrane Library databases were searched for relevant randomized controlled trials (RCTs) from database inception to 2024. Outcomes assessed included AAA growth rate, rate of referral for aneurysm surgery, overall mortality, and discontinuation from adverse effects. Data was analyzed using R software, and P-score was used to rank different treatments. The GRADE framework was performed to assess quality of evidence. RESULTS Thirteen RCTs comprising 3084 patients were included in this NMA. AAA diameters ranged from 3.1–4.6 cm in the intervention group and 3.5–4.5 cm in the placebo group. Study-level mean annual growth rate ranged from 1.2–2.8 mm/year in the intervention group compared with placebo (1.2–2.6 mm/year). There were no significant differences in AAA growth among the compared groups, (P-score probability in brackets): propranolol (0.73) telmisartan (0.66), antibiotics (0.53), placebo (0.53), ACE inhibitors (0.52), ticagrelor (0.46), and pemirolast (0.06). There were no significant differences among the compared groups in terms of aneurysm surgery referral rates, with propranolol (0.91), antibiotics (0.56), placebo (0.45), and pemirolast (0.08) showing similar outcomes. Similarly, no significant differences were observed in overall mortality rates across the groups, including telmisartan (0.87), antibiotics (0.57), ACE inhibitors (0.51), placebo (0.35), and propranolol (0.17). However, propranolol (OR = 3.14, 95% CI 1.34, 7.35) and ticagrelor (OR = 5.10, 95% CI 1.12, 23.18) were associated with a higher rate of discontinuation due to adverse events. Most of the studies analysed demonstrate moderate quality evidence. CONCLUSIONS Current evidence highlights ongoing uncertainty regarding the efficacy of medical therapies in reducing subthreshold AAA growth rates, rates of referral for surgical repair, or overall mortality. The absence of statistically significant benefit may reflect underpowered datasets rather than definitive treatment inefficacy. Future large-scale, appropriately powered randomized controlled trials evaluating emerging medical treatments are required to accurately assess their clinical potential.