Bain Capital Life Sciences holds 12.18% in Heartflow (HTFL)

Rhea-AI Filing Summary

Bain Capital Life Sciences affiliate reports March 31, 2026 holdings in Heartflow. BCLS Fund III Investments, LP states it beneficially owns 10,448,158 shares of Common Stock, representing 12.18% of outstanding shares. The percentage is calculated using 85,757,754 shares outstanding as of February 28, 2026 per the issuer's Form 10-K.

The filing attributes shared voting and dispositive power to Bain Capital Life Sciences entities through managerial relationships; sole voting and dispositive power are reported as 0. Signature is by a partner of Bain Capital Life Sciences Investors, LLC.

Insights

Institutional Ownership Analyst

Bain Capital Life Sciences reports a 12.18% passive stake in Heartflow as of March 31, 2026.

BCLS Fund III Investments, LP reports beneficial ownership of 10,448,158 shares with shared voting and shared dispositive power. The filing follows Schedule 13G/A conventions for passive or qualifying institutional holders and cites the issuer's outstanding share base of 85,757,754 shares as of February 28, 2026.

Dependencies include the issuer's reported share count and the managerial relationships among Bain Capital entities that create shared control. Subsequent disclosures or amendments would update percentages if the outstanding share count or holdings change.

Corporate Governance Specialist

Filing emphasizes shared control via manager and general partner entities, not sole control.

The Schedule 13G/A states shared voting power: 10,448,158 and shared dispositive power: 10,448,158, with sole powers recorded as 0. The language ties authority to Bain Capital Life Sciences Investors, LLC and related entities.

Material impact depends on whether the position is passive; the excerpt does not state any change in intent. Future amendments would reflect any shift from passive to active status or changes in holdings.

Key Figures

Shares beneficially owned: 10,448,158 shares Percent of class: 12.18% Shares outstanding (issuer): 85,757,754 shares +2 more

5 metrics

Shares beneficially owned 10,448,158 shares as of March 31, 2026

Percent of class 12.18% based on 85,757,754 shares outstanding as of February 28, 2026

Shares outstanding (issuer) 85,757,754 shares as of February 28, 2026 per issuer Form 10-K

Shared voting power 10,448,158 shares reported in Item 4(c)(ii)

Sole voting power 0 reported in Item 4(c)(i)

Key Terms

Schedule 13G/A, Beneficial ownership, Shared dispositive power, Manager/General Partner relationships

4 terms

Schedule 13G/A regulatory

"Item 2(a) and form header identifying the filing as an amendment"

A Schedule 13G/A is an amended public filing with the U.S. securities regulator that updates a previous Schedule 13G, disclosing when an individual or group holds a substantial (typically over 5%) stake in a company and is claiming a passive, non‑controlling intent. Investors monitor these updates because rising or falling holdings can signal changing confidence, potential future moves, or shifts in voting power — like watching a public ledger where large shareholders quietly adjust their positions.

Beneficial ownership financial

"Item 4(a) "the Reporting Person held 10,448,158 shares of Common Stock""

Beneficial ownership means the person or entity that actually enjoys the benefits of owning shares or other assets — such as receiving dividends, voting rights, or price gains — even if the legal title is held in another name. For investors it matters because knowing who truly controls and profits from a company reveals who can influence decisions, exposes potential conflicts of interest or hidden concentration of power, and affects transparency and risk in the stock.

Shared dispositive power regulatory

"Item 4(c)(iv) "Shared power to dispose...: 10,448,158""

Manager/General Partner relationships other

"Item 2(a) describing BCLSI, BCLS Fund III GP and related entities"

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 1)

Heartflow, Inc.

(Name of Issuer)

Common Stock, $0.001 par value per share

(Title of Class of Securities)

42238D107

(CUSIP Number)

03/31/2026

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

Rule 13d-1(b)

Rule 13d-1(c)

Rule 13d-1(d)

schemaVersion:

SCHEDULE 13G

CUSIP Number(s): 42238D107

1

Names of Reporting Persons

BCLS Fund III Investments, LP

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 10,448,158.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 10,448,158.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

10,448,158.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

12.18 %

12

Type of Reporting Person (See Instructions)

PN

SCHEDULE 13G

Item 1.
(a)	Name of issuer: Heartflow, Inc.
(b)	Address of issuer's principal executive offices: 331 E. Evelyn Avenue, Mountain View, California, 94041.
Item 2.
(a)	Name of person filing: 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.
(b)	Address or principal business office or, if none, residence: The principal business address for each of the Bain Capital Life Sciences Entities is 200 Clarendon Street, Boston, Massachusetts 02116.
(c)	Citizenship: Each of the Bain Capital Life Sciences Entities is organized under the laws of the State of Delaware.
(d)	Title of class of securities: Common Stock, $0.001 par value per share
(e)	CUSIP No.: 42238D107
Item 3.	If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(a)	Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)	Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)	Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)	Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)	An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
(f)	An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
(g)	A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
(h)	A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)	A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)	A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), please specify the type of institution:
(k)	Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
Item 4.	Ownership
(a)	Amount beneficially owned: 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.
(b)	Percent of class: See Item 4(a) hereof.
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: 0
	(ii) Shared power to vote or to direct the vote: 10,448,158
	(iii) Sole power to dispose or to direct the disposition of: 0
	(iv) Shared power to dispose or to direct the disposition of: 10,448,158
Item 5.	Ownership of 5 Percent or Less of a Class.
	Not Applicable
Item 6.	Ownership of more than 5 Percent on Behalf of Another Person.
	Not Applicable
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
	Not Applicable
Item 8.	Identification and Classification of Members of the Group.
	Not Applicable
Item 9.	Notice of Dissolution of Group.
	Not Applicable

Item 10.	Certifications:
	Not Applicable

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

BCLS Fund III Investments, LP

Signature:	/s/ Nicholas Downing
Name/Title:	Nicholas Downing, Partner of Bain Capital Life Sciences Investors, LLC
Date:	05/15/2026

FAQ

What stake does Bain Capital Life Sciences hold in Heartflow (HTFL)?

The filing states Bain Capital Life Sciences' affiliate beneficially owns 10,448,158 shares, equal to 12.18% of Heartflow's outstanding common stock, calculated using 85,757,754 shares outstanding as of February 28, 2026.

Does the Schedule 13G/A show sole voting or dispositive power for BCLS?

No. The filing reports 0 sole voting power and 0 sole dispositive power, while listing 10,448,158 shared voting and 10,448,158 shared dispositive power held by the reporting group.

Which entities are cited as sharing control over the reported shares?

The filing names Bain Capital Life Sciences Investors, LLC, BCLS Fund III GP, BCLS Fund III, and related entities as manager/general partner relationships that may share voting and dispositive power over the reported shares.

What dates anchor the ownership figures in this filing?

The Reporting Person states holdings "as of the close of business on March 31, 2026" and bases the percentage on the issuer's outstanding shares of 85,757,754 as of February 28, 2026 reported in the Form 10-K.

Who signed the Schedule 13G/A amendment for the reporting group?

The form is signed by Nicholas Downing, identified as a Partner of Bain Capital Life Sciences Investors, LLC, with signature date May 15, 2026.