Disease progression is often complex and seemingly unpredictable. Moreover, patients often respond in dramatically different ways to various treatments, and determining the appropriate intervention for a patient can sometimes be difficult. In this paper, we describe an interactive visualization-based system for intervention analysis and apply it to patients at risk of developing congestive heart failure (CHF). Text analysis techniques are used to extract Framingham criteria data from clinical notes. We then correlate the progression of these criteria with intervention data. A visualization-based user interface is provided to allow interactive exploration. We present an overview of the system and share clinician feedback regarding the prototype implementation.