 NEW YORK, July 13, 2021 PRNewswire -- NASDAQ: MDCA MDC Partners Inc. MDC Partners or the Company announced today that it has raised its full-year 2021 guidance for organic revenue growth and Adjusted EBITDA. MDC continues to experience strong demand across its business following its highest first quarter Adjusted EBITDA in Company history, said Mark Penn, Chairman and Chief Executive Officer of MDC Partners. 