Material Event - Form 8-K

As previously reported on a Form 8-Kfiled on August 8, 2023, SeaStar Medical Holding Corporation (the "Company") entered into the First Amendment to the Securities Purchase Agreement (as amended, the "SPA"), dated March 15, 2023, between the Company and an institutional investor (the "Purchaser"), pursuant to which the Purchaser may purchase additional convertible promissory notes of the Company (the "Notes"), convertible into shares of common stock of the Company ("Common Stock"), in an aggregate principal amount up to $2 million. On September 26, 2023, the Company completed the third Additional Closing (as defined in the SPA) by issuing a Note with an initial conversion price equal to the lowest of (i) $0.20, (ii) the closing sale price of Common Stock on the trading day immediately preceding the date of conversion of the Note, and (iii) the average closing sale price of the Common Stock for the five (5) consecutive trading days immediately preceding the conversion date of the Note, in a principal amount of $543,478.26, and a Warrant to purchase up to 738,791 shares of Common Stock.

For more information about the terms of the SPA and related transaction documents, including the terms of the Note and the Warrant, please see the Form 8-Kfiled by the Company on March 16, 2023.