8-K

UNITED STATESSECURITIES AND EXCHANGE COMMISSIONWASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

SeaStar Medical Holding Corporation

(Exact name of Registrant as Specified in Its Charter)

(Former Name or Former Address, if Changed Since Last Report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

Emerging growth company ☒

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 5.07 Submission of Matters to a Vote of Security Holders.

On March 20, 2025, SeaStar Medical Holding Corporation (the “Company”) held its previously announced Special Meeting of Stockholders (the “Special Meeting”). However, the Company did not achieve a quorum and therefore was unable to transact business at the meeting virtually via live webcast at www.proxydocs.com/ICU. During the period of adjournment, the Company will continue to solicit stockholder votes. The record date for the determination of stockholders of the Company entitled to vote at the adjourned Special Meeting remains the close of business on January 31, 2025.

Pursuant to the Company’s bylaws, whether or not there is such a quorum at any meeting, the presiding officer of the meeting may adjourn the meeting from time to time without notice other than announcement at the meeting. Accordingly, the Special Meeting was adjourned to March 28, 2025, at 10:00 AM Mountain Daylight Time.

At the adjourned Special Meeting on March 28, 2025, stockholders will be deemed to be present in person and vote at such adjourned meeting in the same manner as disclosed in the definitive proxy statement the Company filed with the Securities and Exchange Commission on February 28, 2025. Valid proxies submitted prior to the reconvened Special Meeting will continue to be valid for the upcoming reconvened Special Meeting, unless properly changed or revoked prior to votes being taken at such reconvened Special Meeting.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.