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                                                                     EXHIBIT 4.3

                                 SIXTH AMENDMENT

         SIXTH AMENDMENT, dated as of June 23, 2000 (this "Sixth Amendment"), to
the Agreement and Amendment dated as of February 26, 1997, as amended by the
First Amendment, dated as of June 17, 1997, the Second Amendment, dated as of
February 3, 1998, the Third Amendment, dated as of March 26, 1998, the Fourth
Amendment, dated as of July 10, 1998 and the Fifth Amendment dated as of March
30, 1999 (as the same may be amended, supplemented or modified from time to
time, the "February 1997 Five-Year Agreement and Amendment") among HCA - THE
HEALTHCARE COMPANY (formerly known as Columbia/HCA Healthcare Corporation), a
Delaware corporation (the "Company"), the several banks and other financial
institutions from time to time parties hereto (the "Banks"), BANK OF AMERICA,
N.A., THE BANK OF NEW YORK, DEUTSCHE BANK AG, FLEET NATIONAL BANK, THE FUJI BANK
LIMITED, THE INDUSTRIAL BANK OF JAPAN, LIMITED, MORGAN GUARANTY TRUST COMPANY OF
NEW YORK, PNC BANK NATIONAL ASSOCIATION, TORONTO DOMINION (TEXAS), INC., UNION
BANK OF SWITZERLAND, NEW YORK BRANCH AND WACHOVIA BANK, N.A., as co-agents
(collectively, the "Co-Agents"), THE SAKURA BANK, LTD. NEW YORK BRANCH, THE
SUMITOMO BANK LIMITED, SUNTRUST BANK, WELLS FARGO BANK, N.A., as Lead Managers
(collectively, the "Lead Managers") and THE CHASE MANHATTAN BANK, a New York
banking corporation, as agent for the Banks hereunder ("Chase", and in such
capacity, the "Agent") and as CAF Loan Agent (in such capacity, the "CAF Loan
Agent").

                              W I T N E S S E T H :

         WHEREAS, for the convenience of the parties to the agreement and
amendment dated as of February 28, 1996 (the "February 1996 Agreement and
Amendment"), among the Company, the several banks and other financial
institutions from time to time parties thereto and Chase, as agent for the Banks
hereunder and as CAF Loan Agent, a composite conformed copy (the "Five-Year
Composite Conformed Credit Agreement") of the Credit Agreement, dated as of
February 10, 1994 as incorporated by reference into and amended by the September
1994 Agreement and Amendment, the February 1995 Agreement and Amendment and the
February 1996 Agreement and Amendment was prepared and delivered to such
parties;

         WHEREAS, the February 1997 Five-Year Agreement and Amendment adopts and
incorporates by reference all of the terms and provisions of the Five-Year
Composite Conformed Credit Agreement, subject to the amendment thereto provided
for in the February 1997 Five-Year Agreement and Amendment;

         WHEREAS, the parties hereto wish to amend certain provisions of the
February 1997 Five-Year Agreement and Amendment on the terms set forth herein;





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         NOW, THEREFORE, in consideration of the premises and of the mutual
agreements herein contained, the parties hereto agree as follows:

         1. Definitions. Unless otherwise defined herein, terms defined in the
February 1997 Five-Year Agreement and Amendment shall be used as so defined.

         2. Amendments to the February 1997 Five-Year Agreement and Amendment in
respect of the Letter of Credit Facility. Section 3 of the February 1997
Five-Year Agreement and Amendment is hereby amended by deleting the defined term
"Consolidated Earnings Before Interest and Taxes" in its entirety and
substituting in lieu thereof the following new defined term in proper
alphabetical order:

            "'Consolidated Earnings Before Interest and Taxes': for any period
     for which the amount thereof is to be determined, Consolidated Net Income
     for such period, plus (i) all amounts deducted in computing such
     Consolidated Net Income in respect of interest expense on Indebtedness and
     income taxes and (ii) non-recurring charges incurred or made as of or for
     fiscal quarters ending on or after June 30, 2000 related to the Company's
     partial settlement with the Department of Justice not exceeding in the
     aggregate $745,000,000 on a pre-tax basis."

         3. Effective Date; Conditions Precedent. This Sixth Amendment will
become effective on June 23, 2000 (the "Effective Date") subject to the
compliance by the Company with its agreements herein contained and to the
satisfaction on or before the Effective Date of the following further
conditions:

            (a) Loan Documents. The Agent shall have received copies of this
     Sixth Amendment, executed and delivered by a duly authorized officer of the
     Company, with a counterpart for each Bank, and executed and delivered by
     the Required Banks.

            (b) Fees. The Agent shall have received, for the account of each
     Bank which executes and delivers this Amendment on or prior to 5:00 p.m.
     New York City time on June 23, 2000, an amendment fee in an amount equal to
     2.5 basis points on such Bank's Commitment as in effect prior to the
     Effective Date, payable in immediately available funds on or before the
     Effective Date.

            (c) Company Officers' Certificate. On and as of the Effective Date
     and after giving effect to this Sixth Amendment, no Default shall have
     occurred (except a Default which shall have been waived in writing or which
     shall have been cured); and the Agent shall have received a certificate
     containing a representation to these effects dated the Effective Date and
     signed by a Responsible Officer.

            (d) Second Amendment to July 1998 Agreement. That certain credit
     agreement, dated as of July 10, 1998, among the Company, the several banks
     and other financial institutions from time to time parties thereto,
     Nationsbank, N.A., The Bank of Nova Scotia, Deutsche Bank Securities, and
     The Chase Manhattan Bank, as administrative agent (the "July 1998
     Agreement"), shall have been amended in a manner corresponding to the
     amendments hereof.




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           (e) First Amendment to March 2000 Agreement. That certain credit
     agreement, dated as of March 13, 2000, among the Company, the several banks
     and other financial institutions from time to time parties thereto, Chase
     Securities Inc., Bank of America, N.A., The Bank of Nova Scotia, Deutsche
     Bank AG New York Branch, The Bank of New York, The Industrial Bank of
     Japan, Limited, Citicorp USA, Inc., Fleet National Bank, Credit Suisse
     First Boston, Suntrust Bank, Wachovia Bank, N.A., and The Chase Manhattan
     Bank, as administrative agent (the "March 2000 Agreement"), shall have been
     amended in a manner corresponding to the amendments hereof.

         4. Legal Obligation. The Company represents and warrants to each Bank
that this Sixth Amendment constitutes the legal, valid and binding obligation of
the Company, enforceable against it in accordance with its terms, subject to the
effects of bankruptcy, insolvency, fraudulent conveyances, reorganization,
moratorium and other similar laws relating to or affecting creditors' rights
generally, general equitable principles (whether considered in a proceeding in
equity or at law) and an implied covenant of good faith and fair dealing.

         5. Continuing Effect; Application. Except as expressly amended hereby,
the February 1997 Five-Year Agreement and Amendment shall continue to be and
shall remain in full force and effect in accordance with its terms.

         6. Expenses. The Company agrees to pay or reimburse the Agent for all
of its reasonable out-of-pocket costs and expenses incurred in connection with
the development, preparation and execution of, and any amendment, supplement or
modification to, this Sixth Amendment and any other documents prepared in
connection herewith, and the consummation of the transactions contemplated
hereby and thereby, including, without limitation, the reasonable fees and
disbursements of counsel to the Agent.

         7. GOVERNING LAW. THIS SIXTH AMENDMENT AND THE RIGHTS AND OBLIGATIONS
OF THE PARTIES UNDER THIS SIXTH AMENDMENT SHALL BE GOVERNED BY, AND CONSTRUED
AND INTERPRETED IN ACCORDANCE WITH, THE LAW OF THE STATE OF NEW YORK.

         8. Counterparts. This Sixth Amendment may be executed by one or more of
the parties to this Sixth Amendment on any number of separate counterparts and
all of said counterparts taken together shall be deemed to constitute one and
the same instrument. A set of the copies of this Sixth Amendment signed by all
the parties shall be lodged with the Company and the Agent.




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         IN WITNESS WHEREOF, the parties hereto have caused this Sixth Amendment
to be duly executed and delivered by their proper and duly authorized officers
as of the day and year first above written.


                                    HCA - THE HEALTHCARE COMPANY



                                    By: /s/ DAVID G. ANDERSON
                                        ----------------------------------------
                                        Name:
                                        Title:


                                    THE CHASE MANHATTAN BANK, as Agent, as CAF
                                    Loan Agent and as a Bank



                                    By: /s/ DAWN LEE LUM
                                        ----------------------------------------
                                        Name:
                                        Title: