Form 8-K

8-K — Cardio Diagnostics Holdings, Inc.

Accession: 0001553350-26-000131

Filed: 2026-09-18

Period: 2026-09-18

CIK: 0001870144

SIC: 2835 (IN VITRO & IN VIVO DIAGNOSTIC SUBSTANCES)

Item: Submission of Matters to a Vote of Security Holders

Item: Financial Statements and Exhibits

Documents

8-K — cdio_8k.htm (Primary)

XML — IDEA: XBRL DOCUMENT (R1.htm)

8-K — FORM 8-K

8-K (Primary)

Filename: cdio_8k.htm · Sequence: 1

8-K

false

0001870144

2026-09-18

0001870144

CDIO:CommonStockParValue0.00001Member

2026-09-18

0001870144

CDIO:RedeemableWarrantsEachWarrantExercisableForOnehalfOfOneShareOfCommonStockMember

2026-09-18

iso4217:USD

xbrli:shares

iso4217:USD

xbrli:shares

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 8-K

Current Report

Pursuant to Section 13 or 15(d) of the

Securities Exchange Act of 1934

September

18, 2026

Date of Report (Date of earliest event reported)

CARDIO DIAGNOSTICS HOLDINGS, INC.

(Exact name of registrant as specified in its charter)

Delaware

001-41097

87-0925574

(State or other jurisdiction

of incorporation)

(Commission File Number)

(I.R.S. Employer

Identification No.)

311

W. Superior Street, Suite 444, Chicago, IL

60654

(Address of principal executive offices)

(Zip Code)

Registrant’s telephone number, including area

code: (855) 226-9991

(Former name or former address, if changed since last

report)

Check the appropriate box below if the Form 8-K filing

is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐ Written

communication pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting

material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement

communication pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement

communication pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b)

of the Act:

Title of each class

Trading Symbol(s)

Name of each exchange on which registered

Common Stock, par value $0.00001

CDIO

The Nasdaq Stock Market LLC

Redeemable Warrants, each warrant exercisable for one share of Common Stock

CDIOW

The Nasdaq Stock Market LLC

Indicate by check mark whether the registrant is an

emerging growth company as defined in Rule 405 of the Securities Act of 1933 (17 CFR §230.405) or Rule 12b-2 of the Securities Exchange

Act of 1934 (17 CFR §240.12b-2).

Emerging

growth company ☒

an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying

with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 5.07.

Submission of Matters to a Vote of Security Holders.

On September

18, 2026, Cardio Diagnostics Holdings, Inc., a Delaware corporation (the “Company”) held its annual meeting of stockholders

(the “Annual Meeting”). Of the Company’s 2,959,469 shares of common stock issued and outstanding and eligible to vote

as of the record date of July 31, 2026, a total of1,783,220 shares, or approximately 60.25% of the eligible shares, was in attendance

or represented by proxy. The Company’s stockholders voted on

three proposals as set forth below. Each of the proposals is described in further detail in the Company’s definitive proxy statement,

which was filed with the Securities and Exchange Commission on August 5, 2026. The final voting results, including the number of votes

cast for, against, or withholding authority, and the number of abstentions and any broker non-votes, with respect to each matter voted

upon are set forth below, as reported by the Company’s independent inspector of election.

Proposal 1: Election of Directors (the “Election of

Directors Proposal”)

The Company’s stockholders elected seven directors to serve for

the ensuing year and until their successors are elected and qualified, or until their earlier death, resignation or removal. The Company

elects its directors on a plurality vote basis. The votes regarding the election of directors were as follows:

Nominee

For

Authority Withheld

Broker Non-Votes

Meeshanthini V. Dogan

1,006,735

150,980

625,505

Warren Hosseinion

974,843

182,872

625,505

Wendy J. Betts

1,018,089

139,626

625,505

Paul F. Burton

1,029,958

127,757

625,505

Peter K. Fung

1,029,127

128,588

625,505

James Intrater

1,009,627

148,088

625,505

Robert Philibert

1,019,672

138,043

625,505

Proposal 2: Approval of the future issuance of shares of Common

Stock and/or securities convertible into or exercisable for Common Stock equal to 20% or more of the Common Stock outstanding in one or

more non-public transactions as required by Nasdaq Marketplace Listing Rule 5635(d) (the “Share Issuance Proposal”)

The Share Issuance Proposal was approved. Any non-public financing

transaction undertaken in connection with this approval will be conducted within the parameters set forth in the Share Issuance Proposal

described in the proxy statement for the Annual Meeting.

For

Against

Abstain

Broker Non-Votes

936,488

193,532

27,695

625,505

Proposal 3: Ratification of Appointment of Independent Registered

Public Accounting Firm (the “Auditor Ratification Proposal”)

The ratification of the appointment of Prager Metis CPA’s LLC

as the Company’s independent registered public accounting firm for the fiscal year ending December 31, 2026 was approved.

For

Against

Abstain

1,722,311

57,874

3,035

Item 9.01. Financial Statements and Exhibits.

(d) Exhibits

Exhibit No.

Description of Exhibit

104

Cover Page Interactive Data File (embedded within the Inline

XBRL document).

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934,

the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

Dated: September 18, 2026

CARDIO DIAGNOSTICS HOLDINGS, INC.

By:

/s/ Elisa Luqman

Elisa Luqman

Chief Financial Officer

XML — IDEA: XBRL DOCUMENT

XML

Filename: R1.htm · Sequence: 7

v3.26.3

Cover

Sep. 18, 2026

Document Type

8-K

Amendment Flag

false

Document Period End Date

Sep. 18, 2026

Entity File Number

001-41097

Entity Registrant Name

CARDIO DIAGNOSTICS HOLDINGS, INC.

Entity Central Index Key

0001870144

Entity Tax Identification Number

87-0925574

Entity Incorporation, State or Country Code

Entity Address, Address Line One

311

W. Superior Street

Entity Address, Address Line Two

Suite 444

Entity Address, City or Town

Chicago

Entity Address, State or Province

Entity Address, Postal Zip Code

60654

City Area Code

(855)

Local Phone Number

226-9991

Written Communications

false

Soliciting Material

false

Pre-commencement Tender Offer

false

Pre-commencement Issuer Tender Offer

false

Entity Emerging Growth Company

true

Elected Not To Use the Extended Transition Period

false

Common Stock, par value $0.00001

Title of 12(b) Security

Common Stock, par value $0.00001

Trading Symbol

CDIO

Security Exchange Name

NASDAQ

Redeemable warrants, each warrant exercisable for one-half of one share of common stock

Title of 12(b) Security

Redeemable Warrants, each warrant exercisable for one share of Common Stock

Trading Symbol

CDIOW

Security Exchange Name

NASDAQ

- Definition

Boolean flag that is true when the XBRL content amends previously-filed or accepted submission.

+ References

No definition available.

+ Details

Name:

dei_AmendmentFlag

Namespace Prefix:

dei_

Data Type:

xbrli:booleanItemType

Balance Type:

Period Type:

duration

- Definition

Area code of city

+ References

No definition available.

+ Details

Name:

dei_CityAreaCode

Namespace Prefix:

dei_

Data Type:

xbrli:normalizedStringItemType

Balance Type:

Period Type:

duration

- Definition

For the EDGAR submission types of Form 8-K: the date of the report, the date of the earliest event reported; for the EDGAR submission types of Form N-1A: the filing date; for all other submission types: the end of the reporting or transition period. The format of the date is YYYY-MM-DD.

+ References

No definition available.

+ Details

Name:

dei_DocumentPeriodEndDate

Namespace Prefix:

dei_

Data Type:

xbrli:dateItemType

Balance Type:

Period Type:

duration

- Definition

The type of document being provided (such as 10-K, 10-Q, 485BPOS, etc). The document type is limited to the same value as the supporting SEC submission type, or the word 'Other'.

+ References

No definition available.

+ Details

Name:

dei_DocumentType

Namespace Prefix:

dei_

Data Type:

dei:submissionTypeItemType

Balance Type:

Period Type:

duration

- Definition

Address Line 1 such as Attn, Building Name, Street Name

+ References

No definition available.

+ Details

Name:

dei_EntityAddressAddressLine1

Namespace Prefix:

dei_

Data Type:

xbrli:normalizedStringItemType

Balance Type:

Period Type:

duration

- Definition

Address Line 2 such as Street or Suite number

+ References

No definition available.

+ Details

Name:

dei_EntityAddressAddressLine2

Namespace Prefix:

dei_

Data Type:

xbrli:normalizedStringItemType

Balance Type:

Period Type:

duration

- Definition

Name of the City or Town

+ References

No definition available.

+ Details

Name:

dei_EntityAddressCityOrTown

Namespace Prefix:

dei_

Data Type:

xbrli:normalizedStringItemType

Balance Type:

Period Type:

duration

- Definition

Code for the postal or zip code

+ References

No definition available.

+ Details

Name:

dei_EntityAddressPostalZipCode

Namespace Prefix:

dei_

Data Type:

xbrli:normalizedStringItemType

Balance Type:

Period Type:

duration

- Definition

Name of the state or province.

+ References

No definition available.

+ Details

Name:

dei_EntityAddressStateOrProvince

Namespace Prefix:

dei_

Data Type:

dei:stateOrProvinceItemType

Balance Type:

Period Type:

duration

- Definition

A unique 10-digit SEC-issued value to identify entities that have filed disclosures with the SEC. It is commonly abbreviated as CIK.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection b-2

+ Details

Name:

dei_EntityCentralIndexKey

Namespace Prefix:

dei_

Data Type:

dei:centralIndexKeyItemType

Balance Type:

Period Type:

duration

- Definition

Indicate if registrant meets the emerging growth company criteria.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection b-2

+ Details

Name:

dei_EntityEmergingGrowthCompany

Namespace Prefix:

dei_

Data Type:

xbrli:booleanItemType

Balance Type:

Period Type:

duration

- Definition

Indicate if an emerging growth company has elected not to use the extended transition period for complying with any new or revised financial accounting standards.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Securities Act

-Number 7A

-Section B

-Subsection 2

+ Details

Name:

dei_EntityExTransitionPeriod

Namespace Prefix:

dei_

Data Type:

xbrli:booleanItemType

Balance Type:

Period Type:

duration

- Definition

Commission file number. The field allows up to 17 characters. The prefix may contain 1-3 digits, the sequence number may contain 1-8 digits, the optional suffix may contain 1-4 characters, and the fields are separated with a hyphen.

+ References

No definition available.

+ Details

Name:

dei_EntityFileNumber

Namespace Prefix:

dei_

Data Type:

dei:fileNumberItemType

Balance Type:

Period Type:

duration

- Definition

Two-character EDGAR code representing the state or country of incorporation.

+ References

No definition available.

+ Details

Name:

dei_EntityIncorporationStateCountryCode

Namespace Prefix:

dei_

Data Type:

dei:edgarStateCountryItemType

Balance Type:

Period Type:

duration

- Definition

The exact name of the entity filing the report as specified in its charter, which is required by forms filed with the SEC.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection b-2

+ Details

Name:

dei_EntityRegistrantName

Namespace Prefix:

dei_

Data Type:

xbrli:normalizedStringItemType

Balance Type:

Period Type:

duration

- Definition

The Tax Identification Number (TIN), also known as an Employer Identification Number (EIN), is a unique 9-digit value assigned by the IRS.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection b-2

+ Details

Name:

dei_EntityTaxIdentificationNumber

Namespace Prefix:

dei_

Data Type:

dei:employerIdItemType

Balance Type:

Period Type:

duration

- Definition

Local phone number for entity.

+ References

No definition available.

+ Details

Name:

dei_LocalPhoneNumber

Namespace Prefix:

dei_

Data Type:

xbrli:normalizedStringItemType

Balance Type:

Period Type:

duration

- Definition

Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 13e

-Subsection 4c

+ Details

Name:

dei_PreCommencementIssuerTenderOffer

Namespace Prefix:

dei_

Data Type:

xbrli:booleanItemType

Balance Type:

Period Type:

duration

- Definition

Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 14d

-Subsection 2b

+ Details

Name:

dei_PreCommencementTenderOffer

Namespace Prefix:

dei_

Data Type:

xbrli:booleanItemType

Balance Type:

Period Type:

duration

- Definition

Title of a 12(b) registered security.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection b

+ Details

Name:

dei_Security12bTitle

Namespace Prefix:

dei_

Data Type:

dei:securityTitleItemType

Balance Type:

Period Type:

duration

- Definition

Name of the Exchange on which a security is registered.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection d1-1

+ Details

Name:

dei_SecurityExchangeName

Namespace Prefix:

dei_

Data Type:

dei:edgarExchangeCodeItemType

Balance Type:

Period Type:

duration

- Definition

Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as soliciting material pursuant to Rule 14a-12 under the Exchange Act.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 14a

-Subsection 12

+ Details

Name:

dei_SolicitingMaterial

Namespace Prefix:

dei_

Data Type:

xbrli:booleanItemType

Balance Type:

Period Type:

duration

- Definition

Trading symbol of an instrument as listed on an exchange.

+ References

No definition available.

+ Details

Name:

dei_TradingSymbol

Namespace Prefix:

dei_

Data Type:

dei:tradingSymbolItemType

Balance Type:

Period Type:

duration

- Definition

Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as written communications pursuant to Rule 425 under the Securities Act.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Securities Act

-Number 230

-Section 425

+ Details

Name:

dei_WrittenCommunications

Namespace Prefix:

dei_

Data Type:

xbrli:booleanItemType

Balance Type:

Period Type:

duration

- Details

Name:

us-gaap_StatementClassOfStockAxis=CDIO_CommonStockParValue0.00001Member

Namespace Prefix:

Data Type:

Balance Type:

Period Type:

- Details

Name:

us-gaap_StatementClassOfStockAxis=CDIO_RedeemableWarrantsEachWarrantExercisableForOnehalfOfOneShareOfCommonStockMember

Namespace Prefix:

Data Type:

Balance Type:

Period Type: