HealthDay -- Two new studies have produced mixed results for two different drugs that are often used to treat heart failure. In the first study, researchers found limited benefit from a drug called valsartan (Diovan), which is used to lower systolic blood pressure. The second study found no benefit from the use of a drug known as nesiritide (Natrecor) for heart failure in an outpatient setting. Both reports are published in the May 21 issue of Circulation: Heart Failure.