X0202 SCHEDULE 13G/A 0001952107 XXXXXXXX LIVE 1 Common Stock, $0.001 par value per share 03/31/2026 0001464521 Heartflow, Inc. 42238D107 331 E. Evelyn Avenue Mountain View CA 94041 Rule 13d-1(d) BCLS Fund III Investments, LP DE 0 10448158 0 10448158 10448158 N 12.18 PN Heartflow, Inc. 331 E. Evelyn Avenue, Mountain View, California, 94041. This Schedule 13G is being filed by BCLS Fund III Investments, LP, a Delaware limited partnership (the "Reporting Person"). Bain Capital Life Sciences Investors, LLC, a Delaware limited liability company ("BCLSI"), is the manager of Bain Capital Life Sciences III General Partner, LLC, a Delaware limited liability company ("BCLS Fund III GP"), which is the general partner of Bain Capital Life Sciences Fund III, L.P., a Delaware limited partnership ("BCLS Fund III"), which is the managing member of BCLS Fund III Investments GP, LLC, a Delaware limited liability company (together with the Reporting Person, BCLSI, BCLS Fund III GP and BCLS Fund III, the "Bain Capital Life Sciences Entities"), which is the general partner of the Reporting Person. As a result, BCLSI may be deemed to share voting and dispositive power with respect to the securities held by the Reporting Person. The principal business address for each of the Bain Capital Life Sciences Entities is 200 Clarendon Street, Boston, Massachusetts 02116. Each of the Bain Capital Life Sciences Entities is organized under the laws of the State of Delaware. Y As of the close of business on March 31, 2026, the Reporting Person held 10,448,158 shares of Common Stock, representing approximately 12.2% of the outstanding Common Stock. The percentage of the outstanding shares of Common Stock held by the Reporting Person is based on 85,757,754 shares of Common Stock outstanding as of February 28, 2026, as reported by the Issuer in its Annual Report on Form 10-K for the year ended December 31, 2025, filed with the Securities and Exchange Commission on March 18, 2026. See Item 4(a) hereof. 0 10,448,158 0 10,448,158 Y Y Y Y Y Y BCLS Fund III Investments, LP /s/ Nicholas Downing 05/15/2026