To confirm a diagnosis of congestive heart failure (CHF), which laboratory test is most likely to be prescribed?

B-type natriuretic peptide (BNP) is the most relevant laboratory test for confirming a diagnosis of congestive heart failure (CHF) because it specifically measures the levels of BNP, a hormone released by the heart in response to increased pressure that often occurs in heart failure. Elevated BNP levels are indicative of heart strain and fluid overload, which are characteristic of CHF. A BNP test can help distinguish between heart failure and other causes of dyspnea (shortness of breath).

In contrast, the other tests do not specifically or directly diagnose CHF. The basic metabolic panel evaluates electrolytes and kidney function, which may not provide clear evidence regarding heart failure. The complete metabolic profile includes a wider range of tests but similarly does not specifically indicate heart function issues. C-reactive protein (CRP) assesses inflammation and is not specific for heart failure, thus making BNP the most targeted and effective choice for confirming a diagnosis of CHF.