MAD-MT Score: Enhancing Patient Selection for Mechanical Thrombectomy in Distal Vessel Occlusions

Highlight

• The MAD-MT score combines clinical risk and procedural factors to guide mechanical thrombectomy (EVT) in distal and medium vessel occlusions.
• Patients with a MAD-MT score ≥15 significantly benefit from EVT, showing better 90-day functional outcomes compared to medical management.
• Lower score patients (<15) may experience worse outcomes with EVT, underscoring the importance of cautious patient selection.
• This pragmatic tool aids clinical decisions and trial designs targeting less-studied distal occlusions.

Study Background

Acute ischemic stroke due to occlusion of distal and medium cerebral vessels presents a clinical challenge. While mechanical thrombectomy (endovascular thrombectomy, EVT) is established for large vessel occlusions, its benefit and risk profile for more distal occlusions remain less clear. Distal occlusions often involve smaller vessels, variable collateral circulation, and procedural complexities that may increase risks. Consequently, precise patient selection is crucial to optimize outcomes and avoid futile or harmful interventions. The MAD-MT score aims to integrate clinical urgency and procedural risk to guide EVT use in patients with distal and medium vessel occlusions, addressing a significant unmet need in stroke care.

Study Design

This retrospective cohort study analyzed data from an international registry encompassing 37 stroke centers between 2017 and 2023. The cohort included 1007 patients with acute distal or medium vessel occlusion stroke, excluding those with baseline disability (modified Rankin Scale [mRS] ≥3) or missing data. Patients received either medical management (MM) or EVT. The primary endpoint was poor functional outcome defined as mRS >2 at 90 days.

Multivariable logistic regression identified predictors of poor outcomes in medically managed patients and predictors of EVT failure or complications separately. Predictors of poor medical management outcome were assigned positive weights to reflect clinical need, while predictors of EVT failure or harm were negatively weighted to represent procedural risk. The composite MAD-MT score ranged from -8 to 49, summing these weighted factors. Interaction analysis evaluated how the MAD-MT score modified the effect of EVT versus medical management on functional outcomes.

Key Findings

The study population had a median age of 73 years, with 41% female patients. Of the 1007 patients, 822 underwent EVT and 185 received medical management. In the medical management cohort, higher baseline National Institutes of Health Stroke Scale (NIHSS) scores increased risk of poor outcome (+1 point per NIHSS point), as did absence of intravenous thrombolysis (+7 points).

In the EVT-treated group, procedural failure or complications were more likely with advancing age (-1 point for each 15 years above 25), absence of hypertension (-2 points), and absence of atrial fibrillation (-2 points). These factors were scored negatively reflecting increased procedural risk.

The MAD-MT score significantly modified treatment effect (Pinteraction = 0.048). Patients with high scores (≥15; n=293) experienced better functional outcomes with EVT compared to medical management, with median 90-day mRS scores of 3 versus 4 (P=0.009). Conversely, low-score patients (<15; n=710) had worse outcomes following EVT (median mRS 2) compared to medical treatment (median mRS 1; P=0.014).

These findings underscore the dual importance of clinical severity and procedural risk in determining EVT benefit for distal vessel occlusions.

Expert Commentary

The MAD-MT score represents a novel, evidence-based tool addressing a critical gap in stroke intervention: refined patient selection beyond large vessel occlusions. It balances clinical need—highlighted by baseline stroke severity and absence of thrombolysis—with procedural considerations like age and vascular comorbidities.

Its development from a large, international cohort enhances generalizability. However, as a retrospective study, residual confounding and selection biases cannot be excluded. The heterogeneity of distal occlusions and varied EVT techniques also pose limitations. Prospective validation and randomized controlled trials incorporating MAD-MT guided selection are necessary before widespread adoption.

Furthermore, the lower benefit and potential harm observed in low MAD-MT score patients caution against indiscriminate EVT use in distal occlusions. This tool supports personalized stroke care aligning intervention intensity with patient-specific risk-benefit profiles.

Conclusion

The MAD-MT score is a pragmatic, clinically relevant instrument to optimize patient selection for mechanical thrombectomy in distal and medium vessel occlusion strokes. By integrating predictors of both clinical necessity and procedural risk, it identifies patients most likely to benefit from EVT while minimizing harm. This can facilitate patient-centered treatment decisions and informs the design of future trials targeting this underexplored stroke subgroup. Adoption of MAD-MT may enhance functional outcomes and resource utilization in acute stroke management.

Funding and Clinicaltrials.gov

The original study does not specify funding sources or clinical trial registration details. Further research should ensure transparent funding disclosures and pursue prospective validation through registered trials.

References

1. Chen H, et al. MAD-MT Score: A Tool to Optimize Patient Selection for Mechanical Thrombectomy in Distal Vessel Occlusions. Stroke. 2026 Jul 8. PMID: 42417042.
2. Powers WJ, et al. Guidelines for the Early Management of Patients With Acute Ischemic Stroke. Stroke. 2019;50(12):e344-e418.
3. Goyal M, et al. Endovascular thrombectomy after large-vessel ischemic stroke: a meta-analysis of individual patient data from five randomized trials. Lancet. 2016;387(10029):1723-1731.
4. Nogueira RG, et al. Thrombectomy 6 to 24 Hours after Stroke with a Mismatch between Deficit and Infarct. N Engl J Med. 2018;378(1):11-21.