<PAGE>
                                                                     EXHIBIT 4.3


           This Security is a Registered Security in permanent global form
within the meaning of the Indenture hereinafter referred to and is registered in
the name of the Depositary or a nominee of the Depositary. This Security is
exchangeable for Securities registered in the name of a person other than the
Depositary or its nominee only in the limited circumstances described in the
Indenture. Unless and until it is exchanged in whole or in part for Securities
in definitive registered form, this Security may not be transferred except as a
whole by the Depositary to the nominee of the Depositary or by a nominee of the
Depositary to the Depositary or another nominee of the Depositary or by the
Depositary or any such nominee to a successor Depositary or a nominee of such
successor Depositary.

           Unless this Security is presented by an authorized representative of
The Depository Trust Company (55 Water Street, New York, New York) to the issuer
or its agent for registration of transfer, exchange or payment, and any Security
issued is registered in the name of Cede & Co. or such other name as requested
by an authorized representative of The Depository Trust Company and any payment
hereon is made to Cede & Co., ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE
OR OTHERWISE BY A PERSON IS WRONGFUL since the registered owner hereof, Cede &
Co., has an interest herein.
<PAGE>
No. 2                                                   CUSIP NO.:     101137AB3
                                                        ISIN NO.:   US101137AB33


                                  $ 100,000,000

                               5.45% NOTE DUE 2014


                  BOSTON SCIENTIFIC CORPORATION promises to pay
            to Cede & Co. or registered assigns the principal sum of
                  ONE HUNDRED MILLION DOLLARS ($100,000,000) on
                                 June 15, 2014.

Interest Payment Dates: June 15 and December 15 of each year, commencing
December 15, 2004

Regular Record Dates: June 1 and December 1.


      Reference is hereby made to the further provisions of this Security set
forth on the reverse hereof, which further provisions shall for all purposes
have the same effect as if set forth at this place.

                            [SIGNATURE PAGE FOLLOWS]
<PAGE>
      IN WITNESS WHEREOF, the Company has caused this instrument to be duly
executed.


Dated:  June 25, 2004

                                    BOSTON SCIENTIFIC CORPORATION


                                    By:   /s/ Milan Kofol
                                          --------------------------------------
                                    Name:  Milan Kofol
                                    Title: Vice President, Treasurer and
                                           Investor Relations



  [corporate seal]


Attest:


By:  /s/ Lawrence J. Knopf
     ---------------------------
Name:  Lawrence J. Knopf
Title: Assistant Secretary
<PAGE>
                     TRUSTEE'S CERTIFICATE OF AUTHENTICATION



Dated:  June 25, 2004

            This is one of the Securities of the series designated therein
referred to in the within-mentioned Indenture.

                                    JPMORGAN CHASE BANK,
                                    as Trustee



                                    By: /s/ William G. Keenan
                                        ----------------------------------------
                                    Authorized Officer
<PAGE>
                          [REVERSE OF FORM OF SECURITY]

                          BOSTON SCIENTIFIC CORPORATION


                            5.45% NOTE DUE 2014

            1. Interest. BOSTON SCIENTIFIC CORPORATION, a Delaware corporation
(the "Company", which definition shall include any successor thereto in
accordance with the Indenture (as defined below), promises to pay, until the
principal hereof is paid or made available for payment, interest on the
principal amount set forth on the reverse side hereof at a rate of 5.45% per
annum. Interest on the Securities will accrue from and including the most recent
date to which interest has been paid or, if no interest has been paid, from June
25, 2004 through but excluding the date on which interest is paid. Interest
shall be payable in arrears on June 15 and December 15 of each year (each an
"Interest Payment Date"), commencing December 15, 2004. Interest will be
computed on the basis of a 360-day year of twelve 30-day months.

            2. Method of Payment. The Company will pay interest on the
Securities to the Persons who are registered Holders of Securities at the close
of business on the immediately preceding June 1 and December 1 of each year
(each, a "Regular Record Date"). Holders must surrender Securities to a Paying
Agent to collect principal payments. The Company will pay principal, the
Redemption Price and interest in money of the United States that at the time of
payment is legal tender for payment of public and private debts. At the
Company's option, interest may be paid by check mailed to the registered address
of the Holder or by wire transfer to an account designated by the Holder of this
Security; provided, however, that so long as the Securities are registered in
the name of The Depository Trust Company ("DTC"), or its nominee, all payments
of principal, Redemption Price and interest in respect thereof will be made in
immediately available funds.

            3. Paying Agent and Security Registrar. Initially, JPMorgan Chase
Bank will act as Paying Agent and Security Registrar. The Company may change any
Paying Agent or Security Registrar without notice.

            4. Indenture. The Company issued the Securities under an Indenture,
dated as of June 25, 2004 (the "Indenture"), between the Company and JPMorgan
Chase Bank, as Trustee (the "Trustee"). This Security is one of an issue of
Securities of the Company issued under the Indenture. The terms of the
Securities include those stated in the Indenture and those made part of the
Indenture by reference to the Trust Indenture Act of 1939 as amended from time
to time (the "TIA"). The Securities are subject to all such terms, and Holders
of the Securities are referred to the Indenture and the TIA for a statement of
them. Capitalized terms used herein and not otherwise defined have the meanings
set forth in the Indenture. The Securities constitute senior indebtedness of the
Company and, as such, shall be general unsecured and unsubordinated obligations
of the Company ranking equally with all of the Company's unsecured and
unsubordinated obligations. The Company may, subject to the terms of the
Indenture and applicable law, issue additional Securities under the Indenture.
The Securities issued on June 25, 2004 and any additional Securities
subsequently issued shall be treated as a single class for all
<PAGE>
purposes of the Indenture. The Indenture limits the ability of the Company to
incur certain liens and to merge or consolidate with another entity or transfer
all or substantially all of its property and assets.

               5. Optional Redemption. The Securities are subject to redemption
   upon not less than 30 nor more than 60 days notice mailed to the Holder, at
   any time prior to maturity as a whole or in part, at the election of the
   Company at a price equal to the greater of (i) 100% of the principal amount
   of the Securities to be redeemed or (ii) as determined by a Quotation Agent,
   the sum of the present values of the remaining scheduled payments of
   principal and interest thereon (not including any portion of such payments of
   interest accrued to the date of redemption) discounted to the Redemption Date
   on a semiannual basis (assuming a 360-day year consisting of twelve 30-day
   months) at the Adjusted Treasury Rate plus 12.5 basis points, plus, in each
   case, accrued and unpaid interest on the Securities to the Redemption Date.

            "Adjusted Treasury Rate" means, with respect to any Redemption Date,
   the rate per year equal to the semiannual equivalent yield to maturity of the
   Comparable Treasury Issue, assuming a price for the Comparable Treasury Issue
   (expressed as a percentage of its principal amount) equal to the Comparable
   Treasury Price for such Redemption Date.

            "Comparable Treasury Issue" means the United States Treasury
   security selected by a Quotation Agent as having maturity comparable to the
   remaining term of the Securities to be redeemed that would be utilized, at
   the time of selection and in accordance with customary financial practice, in
   pricing new issues of corporate debt securities of comparable maturity to the
   remaining term of such Securities.

            "Quotation Agent" means the Reference Treasury Dealer appointed by
   the Trustee after consultation with Company.

            "Comparable Treasury Price" means, with respect to any Redemption
   Date, (1) the average of the Reference Treasury Dealer Quotations for such
   Redemption Date, after excluding the highest and lowest such Reference
   Treasury Quotations, or (2) if the Trustee obtains fewer than four such
   Reference Treasury Dealer Quotations, the average of all such quotations.

            "Reference Treasury Dealer Quotations" means, with respect to each
   Reference Treasury Dealer and any Redemption Date, the average, as determined
   by the Trustee, of the bid and ask prices for the Comparable Treasury Issue
   (expressed in each case as a percentage of its principal amount) quoted in
   writing to the Trustee by such Reference Treasury Dealer at 5:00 p.m. on the
   third Business Day preceding such Redemption Date.

            6. Sinking Fund. No sinking fund is provided for the Securities.

            7. Denominations, Transfer, Exchange. The Securities are in
registered form without coupons in denominations of $1,000 and integral
multiples of $1,000. A Holder may transfer or exchange Securities in accordance
with the Indenture. No service charge shall be made for any registration of
transfer or exchange of Securities, but the Company may require payment of a sum
sufficient to cover any tax or other governmental charge that may be imposed
<PAGE>
in connection with any registration of transfer or exchange of Securities, other
than exchanges pursuant to Section 304, 906, 1107 or 1305 of the Indenture not
involving any transfer.

            8. Persons Deemed Owners. The registered Holder of a Security may be
treated as the owner of it for all purposes.

            9. Unclaimed Money. Subject to any applicable abandoned property
laws, if money for the payment of principal or interest remains unclaimed for
two years, the Trustee or Paying Agent will pay the money back to the Company at
its written request. After that, Holders entitled to the money must look to the
Company for payment as unsecured general creditors unless an "abandoned
property" law designates another Person.

            10. Amendment, Supplement, Waiver. The Company and the Trustee may,
without the consent of the holders of any outstanding Securities, amend, waive
or supplement the Indenture or the Securities for certain specified purposes,
including, among other things, curing ambiguities, defects or inconsistencies,
or making any other change that does not adversely affect the rights of any
Holder in any material respect. Other amendments and modifications of the
Indenture or the Securities may be made by the Company and the Trustee with the
consent of the Holders of not less than a majority of the aggregate principal
amount of the outstanding Securities affected, subject to certain exceptions
requiring the consent of the Holders of each Security affected thereby.

            11. Successor Corporation. When a successor corporation assumes all
the obligations of its predecessor under the Securities and the Indenture and
the transaction complies with the terms of Article 8 of the Indenture, the
predecessor corporation, subject to certain exceptions, will be released from
those obligations.

            12. Defaults and Remedies. Events of Default are set forth in the
Indenture. Subject to certain limitations in the Indenture, if an Event of
Default (other than an Event of Default specified in Section 501(5) or Section
501(6) of the Indenture) occurs and is continuing, then the Holders of not less
than 25% in aggregate principal amount of the Outstanding Securities may, or the
Trustee may, declare the principal of, plus accrued interest, if any, to be due
and payable immediately. If an Event of Default specified in Section 501(5) or
Section 501(6) of the Indenture occurs and is continuing, the principal of and
accrued interest on all of the Securities shall ipso facto become and be
immediately due and payable without any declaration or other act on the part of
the Trustee or any Holder. Holders of the Securities may not enforce the
Indenture or the Securities except as provided in the Indenture. The Trustee may
require indemnity reasonably satisfactory to it before it enforces the Indenture
or the Securities. Subject to certain limitations, Holders of a majority in
principal amount of the then Outstanding Securities may direct the Trustee in
its exercise of any trust or power. The Company must furnish an annual
compliance certificate to the Trustee.

            13. No Recourse Against Others. A director, officer, employee, or
stockholder, as such, of the Company or any of its Affiliates shall not have any
liability for any obligations of the Company under the Securities or the
Indenture or for any claim based on, in respect of or by reason of, such
obligations or their creation. Each Holder of the Securities by accepting a
<PAGE>
Security waives and releases all such liability. The waiver and release are part
of the consideration for the issue of the Securities.

            14. Defeasance. The Indenture contains provisions (which provisions
apply to this Security) for defeasance at any time of (a) the entire
indebtedness of the Company in respect of this Security and (b) certain
restrictive covenants and Defaults and Events of Default, in each case upon
compliance by the Company with certain conditions set forth therein.

            15. Authentication. This Security shall not be valid until the
Trustee signs the certificate of authentication to this Security.

            16. GOVERNING LAW. THE INDENTURE AND THIS SECURITY SHALL BE GOVERNED
BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK.

            The Company will furnish to any Holder of Securities upon written
request and without charge a copy of the Indenture. Requests may be made to:

            BOSTON SCIENTIFIC CORPORATION
            One Boston Scientific Place
            Natick, Massachusetts  01760
            Telephone:  (508) 650-8000
            Telecopy:  (508) 650-8956
            Attention:  General Counsel
<PAGE>
                                 ASSIGNMENT FORM

If you the holder want to assign this Security, fill in the form below and have
your signature guaranteed:

            I or we assign and transfer this Security to________________________
________________________________________________________________________________
(Insert assignee's social security or tax ID number)____________________________
________________________________________________________________________________
(Print or type assignee's name, address and zip code) and irrevocably appoint
__________________ agent to transfer this Security on the books of the Company.
The agent may substitute another to act for him.
________________________________________________________________________________

Date: ____________________  Your signature:____________________________________
                                           (Sign exactly as your name appears on
                                           the other side of this Security)

Signature Guarantee:____________________________________________________________

            Signatures must be guaranteed by an "eligible guarantor institution"
meeting the requirements of the Security Registrar, which requirements include
membership or participation in the Securities Transfer Agents Medallion Program
("STAMP") or such other "signature guarantee program" as may be determined by
the Security Registrar in addition to, or in substitution for, STAMP, all in
accordance with the Securities Exchange Act of 1934, as amended.