Statement of Changes in Beneficial Ownership (Form 4)

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b). Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person * Bain Capital Life Sciences Investors, LLC 2. Issuer Name and Ticker or Trading Symbol Heartflow, Inc. [HTFL] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director __X__ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 200 CLARENDON STREET 3. Date of Earliest Transaction (Month/Day/Year) 08/11/2025 (Street) BOSTON, MA 02116 4. If Amendment, Date Original Filed (Month/Day/Year) 6. Individual or Joint/Group Filing (Check Applicable Line) ___ Form filed by One Reporting Person _X_ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 08/11/2025 C 12,014,234 A (1) 12,014,234 I See footnotes(3)(4) Common Stock 08/11/2025 C 433,924 A $15.2 12,448,158 I See footnotes(3)(4)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Series F Preferred Stock

(1)

08/11/2025

C

35,081,564

(1)

(1)

Common Stock

12,014,234

$ 0

0

I

See footnotes(3)(4)

Subordinated Convertible Promissory Note

$15.2

08/11/2025

C

$6,595,648.51

(2)

01/24/2029

Common Stock

433,924

$ 0

0

I

See footnotes(3)(4)

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Bain Capital Life Sciences Investors, LLC 200 CLARENDON STREET BOSTON, MA 02116		X
Bain Capital Life Sciences III General Partner, LLC 200 CLARENDON STREET BOSTON, MA 02116		X
Bain Capital Life Sciences Fund III, L.P. 200 CLARENDON STREET BOSTON, MA 02116		X
BCLS Fund III Investments GP, LLC 200 CLARENDON STREET BOSTON, MA 02116		X
BCLS Fund III Investments, LP 200 CLARENDON STREET BOSTON, MA 02116		X

Signatures

See signatures included in Exhibit 99.1		08/13/2025
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	Each share of the Issuer's Series F Preferred Stock automatically converted into shares of the Issuer's Common Stock on a 0.342466:1 basis immediately prior to the closing of the Issuer's initial public offering. These securities had no expiration date.
(2)	The outstanding principal amount of the Subordinated Convertible Promissory note automatically converted into shares of the Issuer's Common Stock upon consummation of the Issuer's initial public offering at a conversion price of 80% of the price per share in the Issuer's initial public offering.
(3)	Represents securities held directly by BCLS Fund III Investments, LP ("BCLS Fund III Investments").
(4)	Bain Capital Life Sciences Investors, LLC ("BCLSI") is the manager of Bain Capital Life Sciences III General Partner, LLC ("BCLS Fund III GP"), which is the general partner of Bain Capital Life Sciences Fund III, L.P. ("BCLS Fund III"), which is the managing member of BCLS Fund III Investments GP, LLC ("BCLS Fund III Investments GP"), which is the general partner of BCLS Fund III Investments. As a result, each of BCLSI, BCLS Fund III GP, BCLS Fund III and BCLS Fund III Investments GP may be deemed to share voting and dispositive power with respect to the securities held by BCLS Fund III Investments. BCLSI, BCLS Fund III GP, BCLS Fund III and BCLS Fund III Investments GP each disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

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