SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                  SCHEDULE 13G
                                (RULE 13d - 102)

      INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO 13d-1(b),
            (c) AND (d) AND AMENDMENTS THERETO FILED PURSUANT TO 13d

                                (Amendment No.)*
Healthcare Acquisition Corp.
-------------------------------------
(Name of Issuer)

Common Stock
------------
(Title of Class of Securities)

42224H104
-------------------
(CUSIP Number)

October 17, 2005
-------------------------
(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)
[x]      Rule 13d-1(c)
[ ]      Rule 13d-1(d)

*The  remainder of this cover page shall be filled out for a reporting  person's
initial filing on this form with respect to the subject class of securities, and
for  any  subsequent   amendment   containing   information  which  would  alter
disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the  Securities  Exchange  Act of
1934 ("Act") or otherwise  subject to the liabilities of that section of the Act
but  shall be  subject  to all other  provisions  of the Act  (however,  see the
Notes).

                      




<PAGE>


1. NAMES OF REPORTING PERSONS
   I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

                  Amaranth LLC

2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*

                  (a) [ ] 
                  (b) [x]

3. SEC USE ONLY

4. CITIZENSHIP OR PLACE OF ORGANIZATION

                  Cayman Islands

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH:

5. SOLE VOTING POWER

                  0

6. SHARED VOTING POWER

                  726,150
                ---------

7. SOLE DISPOSITIVE POWER

                  0

8. SHARED DISPOSITIVE POWER

                  726,150
                ---------

9. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

                  See 6 and 8 above.

10.CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* []

11.PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

                  6.2%
                ------

12. TYPE OF REPORTING PERSON*

                  CO



<PAGE>


1. NAMES OF REPORTING PERSONS
   I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

                  Amaranth Advisors L.L.C.

2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*

                  (a) [ ] 
                  (b) [x]

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

6. SHARED VOTING POWER

                  726,150
                ---------

7. SOLE DISPOSITIVE POWER

                  0

8. SHARED DISPOSITIVE POWER

                  726,150
                  -------

9. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

                  See 6 and 8 above.

10.CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* []

11.PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

                  6.2%
                  ----

12. TYPE OF REPORTING PERSON*

                  IA



<PAGE>




1. NAMES OF REPORTING PERSONS
   I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

                  Nicholas M. Maounis

2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*

                  (a) [ ] 
                  (b) [x]

3. SEC USE ONLY

4. CITIZENSHIP OR PLACE OF ORGANIZATION

                  United States

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH

5. SOLE VOTING POWER

                  0

6. SHARED VOTING POWER

                  726,150
                  ------- 

7. SOLE DISPOSITIVE POWER

                  0

8. SHARED DISPOSITIVE POWER

                  726,150
                  -------

9. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 

                  See 6 and 8 above.

10.CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* []

11.PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

                  6.2%
                  ----

12. TYPE OF REPORTING PERSON*

                  IN, HC

<PAGE>


ITEM 1(a).        Name of Issuer:

         Healthcare Acquisition Corporation
-------------------------------------------

Item 1(b).        Address of Issuer's Principal Executive Offices:

2116 Financial Center
---------------------
666 Walnut Street
-----------------
Des Moines, IA 50309
--------------------
             

Item 2(a).        Name of Persons Filing:
Item 2(b).        Address of Principal Business Office or, if None, Residence:
Item 2(c).        Citizenship:

         Amaranth LLC
         c/o Amaranth Advisors L.L.C.
         One American Lane
         Greenwich, Connecticut 06831
         Cayman Islands company

         Amaranth Advisors L.L.C.
         One American Lane
         Greenwich, Connecticut 06831
         Delaware limited liability company

         Nicholas M. Maounis
         c/o Amaranth Advisors L.L.C.
         One American Lane
         Greenwich, Connecticut 06831
         U.S. Citizen

Amaranth  Advisors L.L.C.  is the trading advisor for Amaranth LLC  ("Amaranth")
and has been granted investment discretion over portfolio investments, including
the Common Stock (as defined below),  held by it. Maounis is the managing member
of  Amaranth  Advisors  L.L.C.  and may,  by virtue of his  position as managing
member, be deemed to have power to direct the vote and disposition of the Common
Stock held for Amaranth.


Item 2(d).        Title of Class of Securities

                  Common Stock, $0.0001 Par Value ("Common Stock")
                  ------------------------------------------------

Item 2(e).        CUSIP Number:     42224H104
                                ------------------------------


<PAGE>

Item 3. If This Statement is Filed Pursuant to Rule 13d-1(b), or 13d-2(b) or
(c), Check Whether the Person Filing is a:

    (a)   [ ] Broker or dealer registered under Section 15 of the
              Exchange Act.

    (b)   [ ] Bank as defined in Section 3(a)(6) of the Exchange
              Act.

    (c)   [ ] Insurance company defined in Section 3(a)(19) of the
              Exchange Act.

    (d)   [ ] Investment company registered under Section 8 of the
              Investment Company Act.

    (e)   [ ] An investment adviser in accordance with Rule
              13d-1(b)(1)(ii)(E).

    (f)   [ ] An employee benefit plan or endowment fund in
              accordance with Rule 13d-1(b)(1)(ii)(F).

    (g)   [ ] A parent holding company or control person in
              accordance with Rule 13d-1(b)(1)(ii)(G).

    (h)   [ ] A savings association as defined in Section 3(b) of
              the Federal Deposit Insurance Act.

    (i)   [ ] A church plan that is excluded from the definition
              of an investment company under Section 3(c)(14) of the
              Investment Company Act;

    (j)   [ ] Group, in accordance with Rule 13d-1(b)(1)(ii)(J).

If this statement is filed pursuant to Rule 13d-1(c), check this box [x]

Item 4.   Ownership.

          Provide the following information regarding the aggregate number and
percentage of the class of securities of the issuer identified in Item 1.

(a) Amount beneficially owned:

                  726,150
                  -------

(b) Percent of class:

                  6.2%
                  ----


<PAGE>


(c) Number of shares as to which such person has:

        (i) Sole power to vote or direct the vote

                0

       (ii) Shared power to vote or to direct the vote

                See Item 4(a).

       (iii) Sole power to dispose or to direct the disposition of

                0

       (iv) Shared power to dispose or to direct the disposition of

                See Item 4(a).


Item 5.   Ownership of Five Percent or Less of a Class.

          If this  statement  is being  filed to report  the fact that as of the
          date hereof the  Reporting  Persons  have ceased to be the  beneficial
          owner of more than five percent of the class of securities,  check the
          following [ ]. Not applicable.

Item 6.   Ownership of More than Five Percent on Behalf of Another Person.

          Shareholders  of  Amaranth  indirectly  participate  in the receipt of
          dividends  from,  and proceeds from the sale of, the Common Stock held
          for the account of Amaranth.

Item 7.   Identification  and  Classification  of the  Subsidiary  Which  
          Acquired the Security Being Reported on by the Parent Holding
          Company.

          Not applicable.

Item 8.   Identification and Classification of Members of the Group.

          See Item 2 in lieu of an Exhibit.

Item 9.   Notice of Dissolution of Group.

          Not applicable.




<PAGE>



Item 10.  Certification.

          By signing below the  undersigned  certifies  that, to the best of its
          knowledge  and  belief,  the  securities  referred  to above  were not
          acquired  and are not held for the  purpose  of or with the  effect of
          changing or  influencing  the control of the issuer of the  securities
          and were not  acquired  and are not  held in  connection  with or as a
          participant in any transaction having that purpose or effect.



<PAGE>


                                   SIGNATURES

     After reasonable inquiry and to the best of its knowledge and belief,  each
of the undersigned  certifies that the information  with respect to it set forth
in this statement is true, complete, and correct.


Dated:   October 27, 2005
         ----------------

          AMARANTH LLC
                   by Amaranth Advisors L.L.C., as Trading Advisor

                   By:  /s/ Nicholas M. Maounis
                        ------------------------------------
                        Nicholas M. Maounis, Managing Member


          AMARANTH ADVISORS L.L.C.

                   By:  /s/ Nicholas M. Maounis
                        ------------------------------------
                        Nicholas M. Maounis, Managing Member


          NICHOLAS M. MAOUNIS

                        /s/ Nicholas M. Maounis
                        -----------------------
                        Nicholas M. Maounis




<PAGE>




                                    EXHIBIT A
                             JOINT FILING AGREEMENT

     The  undersigned  hereby agree that the statement on Schedule 13G signed by
each of the  undersigned  shall be,  filed on behalf of each of the  undersigned
pursuant to and in accordance  with the  provisions  of Rule 13d-1(k)  under the
Securities Exchange Act of 1934, as amended.

Dated:   October 27, 2005
         ----------------

          AMARANTH LLC
                   by Amaranth Advisors L.L.C., as Trading Advisor

                   By:  /s/ Nicholas M. Maounis
                        ------------------------------------
                        Nicholas M. Maounis, Managing Member


          AMARANTH ADVISORS L.L.C.

                   By:  /s/ Nicholas M. Maounis
                        ------------------------------------
                        Nicholas M. Maounis, Managing Member


          NICHOLAS M. MAOUNIS

                        /s/ Nicholas M. Maounis
                        -----------------------
                        Nicholas M. Maounis