Clinicians in Venture: Dr. Timothy Martens & Alex Tang on Vaark Ventures, AI Hype, and Building Fundable Healthcare Startups

On the Underdog Physician podcast, we interview Dr. Timothy Martens, a congenital cardiothoracic surgeon and venture partner, and Alex Tang, a clinical strategy and innovation leader, about their work at Vaark Ventures supporting clinician-led early-stage healthcare startups. Tim recounts shifting from neuroscience and an interest in neurosurgery to cardiac surgery, then gaining commercialization and FDA exposure through stem cell and tissue engineering research at Columbia, later forming Vaark Ventures as a venture studio that evolved into an active angel syndicate with a diverse membership of clinicians, operators, and technical experts. Alex describes moving from clinical practice into administrative and value-based care roles, building practice models, and bringing payer and revenue-cycle perspective to investing. They outline a thesis focused on solving real “pain points” in healthcare, warn against superficial AI buzzwords, emphasize measurable ROI and workflow solutions, and advise founders on timing, committed teams, validated paid pilots, distribution channels, LOIs, and respectful relationship-building. They also discuss value-based care scaling, mentorship, and using disciplined calendar management.

00:00 Welcome and Guests

01:55 Tim Martins Origin

02:58 From Lab to Venture

05:20 Building Vaark Ventures Network

06:42 Alex Tang Journey

09:59 Investment Thesis

13:14 AI and VC Trends

16:42 Founder Advice

19:50 Value Based Care Playbook

26:06 Go To Market Strategy

30:44 Work Life Integration

32:03 Mentorship and Integrity

34:59 Legacy and Closing