Exhibit 32.1
CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE
SARBANES-OXLEY ACT OF 2002
In connection with the Quarterly Report of Thoratec Corporation (the “Company”) on Form 10-Q for the period ending September 27, 2003 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, D. Keith Grossman, Chief Executive Officer of the Company, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:
| 1. | The Report fully complies with the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934; and | ||
| 2. | The information contained in the Report fairly presents, in all material respects, the financial condition and result of operations of the Company. |
| By: | /s/ D. Keith Grossman | |||
| Date: November 10, 2003 | ||||
| Name: | D. Keith Grossman | |||
| Title: | Chief Executive Officer |
In connection with the Quarterly Report of Thoratec Corporation (the “Company”) on Form 10-Q for the period ending September 27, 2003 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, M. Wayne Boylston, Chief Financial Officer of the Company, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:
| 3. | The Report fully complies with the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934; and | ||
| 4. | The information contained in the Report fairly presents, in all material respects, the financial condition and result of operations of the Company. |
| By: | /s/ M. Wayne Boylston | |||
| Date: November 10, 2003 | ||||
| Name: | M. Wayne Boylston | |||
| Title: | Chief Financial Officer |
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