Boston Scientific said on 18 May 2026 that it had invested $1.5bn in return for an approximately 34% stake in MiRus LLC, a privately held Atlanta developer of cardiovascular and orthopaedic implants.
Why Boston Scientific Corporation is buying MiRus LLC (c.34% stake, with option on TAVR business)
Boston Scientific said aortic stenosis is growing rapidly and that it wants a differentiated TAVR system in its portfolio. MiRus's SIEGEL valve uses a rhenium frame and is designed to be delivered through an 8 French sheath, about half the size of current commercial systems.
Deal terms and financing
Boston Scientific may buy 100% of the MiRus TAVR business by making additional cash payments totalling $3bn after MiRus reaches set clinical and regulatory milestones, with further payments tied to SIEGEL sales. It also received an option over MiRus's mitral and tricuspid replacement valve assets.
Regulatory approvals and timing
The investment was immaterial to Boston Scientific's 2026 adjusted EPS. The SIEGEL valve is investigational and not approved for sale anywhere; MiRus has started the STAR pivotal trial.
