, annually) in the absence of FIGURE 4 Testing and Medication Titration Following Diagnosis of HFrEF Maddox et al. J change in clinical status or some other signal of risk are unwarranted. If echocardiography does not provide an assessment of LVEF, guidelines recommend other mo- dalities including radionuclide ventriculography or mag- netic resonance imaging (3). When recovery of LVEF to >40% is noted in the setting of prior HFrEF, outcomes improve (54). Clinicians are often faced with the question of whether to continue GDMT or reduce/eliminate it in patients with complete LVEF recovery. The recent TRED-HF (Withdrawal of Pharmacological Treatment for Heart Failure in Patients with Recovered Dilated Cardiomyopathy) study examined this question, nding that nearly 50% of subjects with- drawn from GDMT had an HF event within 6 months (55). Therefore, in the absence of a de ned, reversible cause for HFrEF (e.g., tachycardia-mediated cardiomyopathy), current GDMT should be continued (56). 5.2.5. Biomarkers When to Order Natriuretic Peptides B-type natriuretic peptide (BNP) and NT-proBNP are the most studied biomarkers in HF. They play a role in diag- nosis and prognostication: higher concentrations of BNP or NT-proBNP in an ambulatory patient with HFrEF inform high risk, particularly when the concentrations are rising. Current clinical practice guidelines give a Class I recommendation to measure BNP or NT-proBNP to support a clinical diagnosis of HF, assess disease severity, or establish prognosis (3). More recently, biomarkers have been examined for their role as markers of clinical responsiveness to GDMT. This is due, in part, to the fact that a wide range of GDMTs may reduce BNP and NT-proBNP concentrations in par- allel with the bene ts of these therapies. Patients whose natriuretic peptide concentrations do not fall with GDMT ( nonresponders ) have a worse prognosis and more deleterious LV remodeling (7,57,58). 