A Simple Validated Clinical Tool to Predict the Absence of Coronary Artery Disease in Patients With Systolic Heart Failure of Unclear Etiology

Coronary artery disease (CAD) is a major cause of systolic heart failure (HF). Identifying CAD as a cause of systolic HF has prognostic and treatment implications. Whether all patients with systolic HF of unclear etiology should undergo coronary angiography has been controversial. We sought to derive and validate a clinical prediction rule to exclude CAD as a cause of systolic HF. A derivation cohort was formed of consecutive patients who had undergone coronary angiography with a primary diagnosis of systolic HF of unclear etiology (ejection fraction