T.M.I. (Too much information)?

P arents of teenagers will recognize the following scenario: parent comprehensively lecturing teenager on some topic at hand, carefully outlining the rationale for a parental decision, invoking extensive reasoning of why one option is better than another for good adolescent decision-making, etc, etc. Teenager looks away, rolls eyes (possibly, but not necessarily outside of visual field of parent), and mutters, sotto voce, " … T.M.I. …. " Article see p 1719 T.M.I. Too much information. In making clinical decisions , we as clinicians generally believe that more information characterizing our patients' disease processes allows us to make better decisions about therapeutic direction, thereby ultimately improving their quality of life and outcomes. Of course, like many things that we would like to believe, this is not always the case, when the concept is tested rigorously. Over the past few years, several studies have shown that providing an increment of information on which clinicians can base management— compared with management without such information— does not necessarily improve symptoms and/or outcomes. Examples include the Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness (ESCAPE) trial, a ran-domized trial in which in-hospital management based on invasive hemodynamic information from pulmonary artery catheterization did not improve measures of 6-month outcomes in comparison with clinically based management in decompensated heart failure (HF) patients, 1 and the often neutral trial results reported when chronic outpatient HF management is guided according to serial measurements of natriuretic peptide levels, as well. 2 The usual trajectory for such studies is initial validation of a marker associated with a pathophysiology of interest, subsequent demonstration of prognostic value in observational studies showing that abnormal levels of the marker are associated with increased risk of an unfavorable outcome, small studies showing that a therapy can improve the marker, and then finally, therapy directed at the marker in a more definitive study with the expectation of actual improved outcome. The trajectory of natriuretic peptide-guided therapy has certainly played out this way, with generally disappointing results at the final step. In this issue of Circulation, Van Veldhuisen and colleagues report the provocative results of the Diagnostic Outcome Trial in Heart Failure (DOT-HF). 3 They report that providing clinicians with information about intrathoracic impedance (which has been shown to be reflective of intrathoracic fluid accumulation) and basing management on that information did not lead to the hypothesized improvement in a composite of all-cause mortality …