---
schema_version: "secwatch.filing_event.v1"
accession: "0000885725-26-000041"
form_type: "8-K"
ticker: "BSX"
cik: "0000885725"
company_name: "BOSTON SCIENTIFIC CORP"
filed_at: "2026-05-18T11:15:03+00:00"
generated_at: "2026-05-18T11:21:50.966683+00:00"
event_type: "m_and_a"
sentiment: "positive"
materiality_score: 0.85
calibrated_materiality_score: 0.85
confidence: "high"
source: SEC EDGAR
---

# Boston Scientific invests $1.5B for ~34% stake in MiRus, gains option to acquire TAVR system for $3B

## Summary
- Paid $1.5B cash for 33.75% non-voting equity in MiRus; exclusive call option to buy TAVR business for $3.0B upon clinical/regulatory milestones.
- SIEGEL TAVR valve uses proprietary rhenium alloy, nickel-free, balloon-expandable, delivered through 8 Fr sheath; still investigational.
- Option includes right to acquire mitral/tricuspid replacement assets; if option not exercised, equity stake forfeited or reduced ~75%.
- MiRus initiated STAR pivotal trial (up to 1,025 patients) evaluating SIEGEL valve; early feasibility study presented in 2025.
- Investment expected immaterial to 2026 adjusted EPS; collaboration aims to bring differentiated TAVR system to aortic stenosis market.

## SEC filing metadata
- accession: 0000885725-26-000041
- form_type: 8-K
- ticker: BSX
- cik: 0000885725
- company_name: BOSTON SCIENTIFIC CORP
- filed_at: 2026-05-18T11:15:03+00:00
- event_type: m_and_a
- sentiment: positive
- materiality_score: 0.85
- calibrated_materiality_score: 0.85
- confidence: high
- sec_items: 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/885725/000088572526000041/0000885725-26-000041-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/885725/000088572526000041/bsx-20260518.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0000885725-26-000041
- JSON: https://secwatch.observer/filing/0000885725-26-000041.json
- Plain text: https://secwatch.observer/filing/0000885725-26-000041.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.