X0202 SCHEDULE 13G/A 0001952107 XXXXXXXX LIVE 2 Common Stock, $0.001 par value per share 06/30/2026 0001464521 Heartflow, Inc. 42238D107 135 Main Street Suite 1000 San Francisco CA 94105 Rule 13d-1(d) BCLS Fund III Investments, LP DE 0 8448158 0 8448158 8448158 N 9.80 PN Heartflow, Inc. 135 Main Street, Suite 1000, San Francisco, California, 94105. 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 June 30, 2026, the Reporting Person held 8,448,158 shares of Common Stock, representing approximately 9.8% of the outstanding Common Stock. The percentage of the outstanding shares of Common Stock held by the Reporting Person is based on 86,240,828 shares of Common Stock outstanding as of April 30, 2026, as reported by the Issuer in its Quarterly Report on Form 10-Q for the quarter ended March 31, 2026, filed with the Securities and Exchange Commission on May 14, 2026. See Item 4(a) hereof. 0 8,448,158 0 8,448,158 Y Y Y Y Y Y BCLS Fund III Investments, LP /s/ Nicholas Downing 08/14/2026