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:

☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

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.

The annual meeting of stockholders (the “Annual Meeting”) of SeaStar Medical Holding Corporation (the “Company”) was held virtually on July 3, 2025 at 10:00 a.m., Mountain Time. The following proposals were approved by the stockholders, each by the votes set forth below:

Proposal 1. To elect two Class III Directors to serve until the 2028 annual meeting of stockholders, or until their successors shall have been duly elected and qualified:

Proposal 2. To approve an amendment and restatement of the Company’s 2022 Omnibus Equity Incentive Plan (the “Plan”) to (i) increase the number of authorized shares of common stock ("Common Stock") from 570,457, as adjusted for a 1-for-25 reverse stock split, to 2,070,457 and (ii) remove the evergreen provision:

Proposal 3. To approve, in accordance with applicable rules of the Nasdaq Stock Market, the potential future sale and issuance of shares of our common stock to Lincoln Park in accordance with the Lincoln Park Purchase Agreement that would result in Lincoln Park owning in excess of 19.99% of the shares of our common stock outstanding immediately after giving effect to such sale:

Proposal 4. To ratify the appointment of WithumSmith+Brown, PC as our independent registered public accounting firm for the fiscal year ending December 31, 2025:

Proposal 5. To approve a proposal to adjourn or postpone the Annual Meeting to a later date or dates, if necessary, to permit further solicitation and vote of proxies if there are insufficient votes for, or otherwise in connection with, any of the proposals described above:

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.