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



                                 Date of Report
                       (Date of earliest event Reported):

                                February 6, 2001
                               -----------------


                            THERMO CARDIOSYSTEMS INC.
             (Exact name of Registrant as specified in its charter)


Massachusetts                      1-10114                       04-3027040
(State or other                  (Commission                 (I.R.S. Employer
jurisdiction of                   File Number)            Identification Number)
incorporation or
organization)


470 Wildwood Street
Woburn, Massachusetts                                                     01888
(Address of principal executive offices)                              (Zip Code)


                                 (781) 932-8668
                               ------------------
                         (Registrant's telephone number
                              including area code)


<PAGE>


Item 5.     Other Events

      On February  6, 2001,  the  Registrant  issued a press  release,  attached
hereto as Exhibit 99, regarding the Registrant's year end results.

Item 7.     Financial Statements, Pro Forma Financial Information and Exhibits

      (a)   Financial Statements of Business Acquired: not applicable.

      (b)   Pro Forma Financial Information: not applicable.

      (c)   Exhibits

            99 Press Release dated February 6, 2001.


<PAGE>





                                    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, thereunto duly authorized, on this 6th day of February, 2001.



                                        THERMO CARDIOSYSTEMS INC.


                                        By:  /s/ Theo Melas-Kyriazi
                                             -------------------------------
                                             Theo Melas-Kyriazi
                                             Chief Financial Officer



<PAGE>


                                                                     Exhibit 99

                 Thermo Cardiosystems Announces Year-End Results

WOBURN, Mass., February 6, 2001 - Thermo Cardiosystems Inc. (ASE:TCA),  a Thermo
Electron  company,  today reported that revenues for the year ended December 30,
2000,  were $83.7 million,  compared with $79.1 million for 1999. Net income was
$7.5  million,  or $.20 per  diluted  share,  versus $9.6  million,  or $.25 per
diluted  share,  last year.  Results for 2000 reflect a $1.8 million  charge for
employee-retention  costs  and  an  extraordinary  gain  of  approximately  $0.2
million.  Results for 1999 reflect the  favorable  resolution  of the  company's
claim for prior-year  research and development tax credits of $1.5 million,  and
an  extraordinary  gain of  approximately  $1.2 million.  Excluding these items,
diluted  earnings  per  share  would  have  been $.22 and $.18 in 2000 and 1999,
respectively.

     For the fourth quarter of 2000,  reported  diluted  earnings per share were
$.04, compared with $.08 for the same period in 1999. Excluding unusual items in
both periods,  diluted  earnings per share would have been $.05 in 2000,  versus
$.04 last year.

     "Thermo  Cardiosystems  achieved  several  significant  objectives in 2000,
which is particularly  satisfying  given the  uncertainty  resulting from Thermo
Electron's  decision  to sell  the  company,"  said  R.  Michael  Kleine,  chief
executive  officer of Thermo  Cardiosystems.  "Revenues  from our LVAS  business
increased  by 8 percent,  driven by 34 percent  growth in sales of our  electric
HeartMate(R)  LVAS. These increases are noteworthy because 1999 revenues include
a significant  number of electric  HeartMate  systems we sold as part of initial
implementation  programs  following  FDA approval of this  device.  We have been
successful in maintaining  top-line  growth even as we transition our focus away
from  enrolling  new  centers  and  begin  to  emphasize   increasing  HeartMate
utilization.  Additionally,  in July we initiated a clinical trial for HeartMate
II in Israel, with this next-generation LVAS performing  flawlessly throughout a
highly  complicated  first implant.  We have since received  approval to begin a
clinical  trial for HeartMate II in Europe,  and are actively  preparing for the
first implant there, which will take place in Germany."

<TABLE>
<CAPTION>
<S>                                                         <C>            <C>                 <C>                 <C>        <C>

Consolidated Statement of Income
                                                                 Three Months Ended                 Twelve Months Ended
                                                                 ------------------                 -------------------
(In thousands except per share amounts)                     Dec. 30, 2000  Jan. 1, 2000        Dec. 30, 2000  Jan. 1, 2000
--------------------------------------------------------------------------------------------------------------------------
Revenues                                                         $21,468        $19,676             $83,703        $79,090
                                                                 -------        -------             -------        -------
Costs and Operating Expenses:
  Cost of revenues                                                 8,971          8,288              35,094         33,739
  Selling, general, and administrative expenses                    5,986          5,457              23,587         22,018
  Research and development expenses                                4,374          4,567              15,926         15,631
  Restructuring and unusual costs                                    737              -               1,831              -
                                                                 -------        -------             -------        -------
                                                                  20,068         18,312              76,438         71,388
                                                                 -------        -------             -------        -------
Operating Income                                                   1,400          1,364               7,265          7,702
Interest Income                                                    1,975          1,813               7,602          7,086
Interest Expense                                                    (706)          (836)             (2,907)        (3,551)
Other Income                                                           9              -                   3              -
                                                                 -------        -------             -------        -------
Income Before Provision for Income Taxes and Extraordinary Item    2,678          2,341              11,963         11,237
Provision for Income Taxes (a)                                     1,057            597               4,630          2,865
                                                                 -------        -------             -------        -------
Income Before Extraordinary Item                                   1,621          1,744               7,333          8,372
Extraordinary Item (net of income taxes
     of $743, $117, and $743)(b)                                       -          1,212                 191          1,212
                                                                 -------        -------             -------        -------
Net Income                                                       $ 1,621        $ 2,956             $ 7,524        $ 9,584
                                                                 -------        -------             -------        -------
Basic and Diluted Earnings per Share                             $   .04        $   .08             $   .20        $   .25
                                                                 -------        -------             -------        -------
Weighted Average Shares:
  Basic                                                           38,575         38,474              38,555         38,443
                                                                 -------        -------             -------        -------
  Diluted                                                         38,576         38,476              38,574          38,482
                                                                 -------        -------             -------        -------
</TABLE>

(a)  Includes  research  and  development  tax credits of $0.3  million and $1.5
     million in the  three-  and  twelve-month  periods  ended  January 1, 2000,
     respectively.

(b) Represents gain on extinguishment of debt.

      Thermo  Cardiosystems Inc. is a leader in the research,  development,  and
manufacture  of  implantable  left   ventricular-assist   systems  (LVAS).   Its
air-driven and electric HeartMate  heart-assist  devices are implanted alongside
the natural heart and take over the pumping  function of the left  ventricle for
patients  whose  hearts are too damaged or diseased  to produce  adequate  blood
flow.  Both  devices are  approved  for  commercial  sale in the United  States,
Europe, and Canada. The company also supplies  whole-blood  coagulation  testing
equipment and related disposables,  as well as single-use skin-incision devices.
Thermo Cardiosystems is a public subsidiary of Thermo Electron. More information
is available at http://www.thermocardio.com.



                                    -more-



Other Important Information:
The proposed merger and the merger agreement  between Thermo  Cardiosystems  and
Thoratec are described in a joint proxy statement/prospectus that has been filed
with the  Securities  and  Exchange  Commission.  You should read this  document
because it contains important  information about the transaction,  including the
participants   in  the   transaction.   You   can   obtain   the   joint   proxy
statement/prospectus  and other documents  (including the merger agreement) that
have been filed with the Securities  and Exchange  Commission for free when they
are  available  on  the  Securities  and  Exchange   Commission's  Web  site  at
http://www.sec.gov.
Also, if you write us or call us at the
below   address   and  phone   number,   we  will  send  you  the  joint   proxy
statement/prospectus for free when it is available.

      You can call us at (781) 622-1111, or write to us at:

      Investor Relations Department
      Thermo Cardiosystems Inc.
      81 Wyman Street, P.O. Box 9046
      Waltham, MA 02454-9046

The  portions of this news  release  that  relate to future  plans,  events,  or
performance  are  forward-looking  statements.  Investors are cautioned that all
such statements involve risks and uncertainties,  including risks related to the
proposed  transaction between Thermo Cardiosystems and Thoratec and the benefits
thereof,  government regulatory approval processes, and market acceptance of new
products.  These factors, and others, are discussed more fully under the heading
"Risk  Factors"  in  Thoratec's  Registration  Statement  on Form S-4  [File No.
333-49120]  filed with the  Securities  and Exchange  Commission on December 29,
2000,  and in both  companies'  other filings with the  Securities  and Exchange
Commission.  Actual results, events, or performance may differ materially. These
forward-looking  statements  speak  only as of the date  hereof.  None of Thermo
Cardiosystems,  Thoratec,  or  Thermo  Electron  undertakes  any  obligation  to
publicly  release  the  results  of  any  revisions  to  these   forward-looking
statements  that may be made to reflect events or  circumstances  after the date
hereof, or to reflect the occurrence of unanticipated events.



                                    # # #
[{"type": "8-K", "sequence": "1", "filename": "0001.txt", "description": "FORM 8-K", "secsgml_size_bytes": 12495}]
{"company-data": {"conformed-name": "THERMO CARDIOSYSTEMS INC", "cik": "0000841939", "assigned-sic": "3845", "irs-number": "043027040", "state-of-incorporation": "MA", "fiscal-year-end": "0102"}, "filing-values": {"form-type": "8-K", "act": "34", "file-number": "001-10114", "film-number": "1526384"}, "business-address": {"street1": "470 WILDWOOD ST", "street2": "P O BOX 2697", "city": "WOBURN", "state": "MA", "zip": "01888-2697", "phone": "7819328668"}, "mail-address": {"street1": "470 WILDWOOD STREET", "street2": "P O BOX 2697", "city": "WOBURN", "state": "MA", "zip": "01888-2697"}}
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

                                 Date of Report
                       (Date of earliest event Reported):

                                February 6, 2001
                               -----------------

                            THERMO CARDIOSYSTEMS INC.
             (Exact name of Registrant as specified in its charter)

Massachusetts                      1-10114                       04-3027040
(State or other                  (Commission                 (I.R.S. Employer
jurisdiction of                   File Number)            Identification Number)
incorporation or
organization)

470 Wildwood Street
Woburn, Massachusetts                                                     01888
(Address of principal executive offices)                              (Zip Code)

                                 (781) 932-8668
                               ------------------
                         (Registrant's telephone number
                              including area code)
Item 5.     Other Events

      On February  6, 2001,  the  Registrant  issued a press  release,  attached
hereto as Exhibit 99, regarding the Registrant's year end results.

Item 7.     Financial Statements, Pro Forma Financial Information and Exhibits

      (a)   Financial Statements of Business Acquired: not applicable.

      (b)   Pro Forma Financial Information: not applicable.

      (c)   Exhibits

            99 Press Release dated February 6, 2001.
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, thereunto duly authorized, on this 6th day of February, 2001.

                                        THERMO CARDIOSYSTEMS INC.

                                        By:  /s/ Theo Melas-Kyriazi
                                             -------------------------------
                                             Theo Melas-Kyriazi
                                             Chief Financial Officer
Exhibit 99

                 Thermo Cardiosystems Announces Year-End Results

WOBURN, Mass., February 6, 2001 - Thermo Cardiosystems Inc. (ASE:TCA),  a Thermo
Electron  company,  today reported that revenues for the year ended December 30,
2000,  were $83.7 million,  compared with $79.1 million for 1999. Net income was
$7.5  million,  or $.20 per  diluted  share,  versus $9.6  million,  or $.25 per
diluted  share,  last year.  Results for 2000 reflect a $1.8 million  charge for
employee-retention  costs  and  an  extraordinary  gain  of  approximately  $0.2
million.  Results for 1999 reflect the  favorable  resolution  of the  company's
claim for prior-year  research and development tax credits of $1.5 million,  and
an  extraordinary  gain of  approximately  $1.2 million.  Excluding these items,
diluted  earnings  per  share  would  have  been $.22 and $.18 in 2000 and 1999,
respectively.

     For the fourth quarter of 2000,  reported  diluted  earnings per share were
$.04, compared with $.08 for the same period in 1999. Excluding unusual items in
both periods,  diluted  earnings per share would have been $.05 in 2000,  versus
$.04 last year.

     "Thermo  Cardiosystems  achieved  several  significant  objectives in 2000,
which is particularly  satisfying  given the  uncertainty  resulting from Thermo
Electron's  decision  to sell  the  company,"  said  R.  Michael  Kleine,  chief
executive  officer of Thermo  Cardiosystems.  "Revenues  from our LVAS  business
increased  by 8 percent,  driven by 34 percent  growth in sales of our  electric
HeartMate(R)  LVAS. These increases are noteworthy because 1999 revenues include
a significant  number of electric  HeartMate  systems we sold as part of initial
implementation  programs  following  FDA approval of this  device.  We have been
successful in maintaining  top-line  growth even as we transition our focus away
from  enrolling  new  centers  and  begin  to  emphasize   increasing  HeartMate
utilization.  Additionally,  in July we initiated a clinical trial for HeartMate
II in Israel, with this next-generation LVAS performing  flawlessly throughout a
highly  complicated  first implant.  We have since received  approval to begin a
clinical  trial for HeartMate II in Europe,  and are actively  preparing for the
first implant there, which will take place in Germany."
Consolidated Statement of Income
                                                                 Three Months Ended                 Twelve Months Ended
                                                                 ------------------                 -------------------
(In thousands except per share amounts)                     Dec. 30, 2000  Jan. 1, 2000        Dec. 30, 2000  Jan. 1, 2000
--------------------------------------------------------------------------------------------------------------------------
Revenues                                                         $21,468        $19,676             $83,703        $79,090
                                                                 -------        -------             -------        -------
Costs and Operating Expenses:
  Cost of revenues                                                 8,971          8,288              35,094         33,739
  Selling, general, and administrative expenses                    5,986          5,457              23,587         22,018
  Research and development expenses                                4,374          4,567              15,926         15,631
  Restructuring and unusual costs                                    737              -               1,831              -
                                                                 -------        -------             -------        -------
                                                                  20,068         18,312              76,438         71,388
                                                                 -------        -------             -------        -------
Operating Income                                                   1,400          1,364               7,265          7,702
Interest Income                                                    1,975          1,813               7,602          7,086
Interest Expense                                                    (706)          (836)             (2,907)        (3,551)
Other Income                                                           9              -                   3              -
                                                                 -------        -------             -------        -------
Income Before Provision for Income Taxes and Extraordinary Item    2,678          2,341              11,963         11,237
Provision for Income Taxes (a)                                     1,057            597               4,630          2,865
                                                                 -------        -------             -------        -------
Income Before Extraordinary Item                                   1,621          1,744               7,333          8,372
Extraordinary Item (net of income taxes
     of $743, $117, and $743)(b)                                       -          1,212                 191          1,212
                                                                 -------        -------             -------        -------
Net Income                                                       $ 1,621        $ 2,956             $ 7,524        $ 9,584
                                                                 -------        -------             -------        -------
Basic and Diluted Earnings per Share                             $   .04        $   .08             $   .20        $   .25
                                                                 -------        -------             -------        -------
Weighted Average Shares:
  Basic                                                           38,575         38,474              38,555         38,443
                                                                 -------        -------             -------        -------
  Diluted                                                         38,576         38,476              38,574          38,482
                                                                 -------        -------             -------        -------
(a)  Includes  research  and  development  tax credits of $0.3  million and $1.5
     million in the  three-  and  twelve-month  periods  ended  January 1, 2000,
     respectively.

(b) Represents gain on extinguishment of debt.

      Thermo  Cardiosystems Inc. is a leader in the research,  development,  and
manufacture  of  implantable  left   ventricular-assist   systems  (LVAS).   Its
air-driven and electric HeartMate  heart-assist  devices are implanted alongside
the natural heart and take over the pumping  function of the left  ventricle for
patients  whose  hearts are too damaged or diseased  to produce  adequate  blood
flow.  Both  devices are  approved  for  commercial  sale in the United  States,
Europe, and Canada. The company also supplies  whole-blood  coagulation  testing
equipment and related disposables,  as well as single-use skin-incision devices.
Thermo Cardiosystems is a public subsidiary of Thermo Electron. More information
is available at http://www.thermocardio.com.

                                    -more-

Other Important Information:
The proposed merger and the merger agreement  between Thermo  Cardiosystems  and
Thoratec are described in a joint proxy statement/prospectus that has been filed
with the  Securities  and  Exchange  Commission.  You should read this  document
because it contains important  information about the transaction,  including the
participants   in  the   transaction.   You   can   obtain   the   joint   proxy
statement/prospectus  and other documents  (including the merger agreement) that
have been filed with the Securities  and Exchange  Commission for free when they
are  available  on  the  Securities  and  Exchange   Commission's  Web  site  at
http://www.sec.gov.
Also, if you write us or call us at the
below   address   and  phone   number,   we  will  send  you  the  joint   proxy
statement/prospectus for free when it is available.

      You can call us at (781) 622-1111, or write to us at:

      Investor Relations Department
      Thermo Cardiosystems Inc.
      81 Wyman Street, P.O. Box 9046
      Waltham, MA 02454-9046

The  portions of this news  release  that  relate to future  plans,  events,  or
performance  are  forward-looking  statements.  Investors are cautioned that all
such statements involve risks and uncertainties,  including risks related to the
proposed  transaction between Thermo Cardiosystems and Thoratec and the benefits
thereof,  government regulatory approval processes, and market acceptance of new
products.  These factors, and others, are discussed more fully under the heading
"Risk  Factors"  in  Thoratec's  Registration  Statement  on Form S-4  [File No.
333-49120]  filed with the  Securities  and Exchange  Commission on December 29,
2000,  and in both  companies'  other filings with the  Securities  and Exchange
Commission.  Actual results, events, or performance may differ materially. These
forward-looking  statements  speak  only as of the date  hereof.  None of Thermo
Cardiosystems,  Thoratec,  or  Thermo  Electron  undertakes  any  obligation  to
publicly  release  the  results  of  any  revisions  to  these   forward-looking
statements  that may be made to reflect events or  circumstances  after the date
hereof, or to reflect the occurrence of unanticipated events.

                                    # # #