Evaluation and management of the acutely dyspneic patient: the role of biomarkers

The etiology of dyspnea can often be difficult to rapidly and accurately determine and can delay timely and appropriate therapies. The current literature reveals important diagnostic, prognostic, and therapeutic implications of several currently used biomarkers: sensitive d-dimer, myoglobin, creatine kinase-MB, cardiac troponins, and b-type natriuretic peptide. These biomarkers were found to have a high sensitivity and negative predictive value for rapidly ruling out potential serious etiologies of dyspnea, namely, pulmonary embolism (PE), acute myocardial infarction (AMI), and congestive heart failure (CHF). In the setting of a low to moderate pretest probability of PE, a negative sensitive d-dimer can rule out a PE with 97% accuracy. After 10 hours from the onset of symptoms, normal levels of myoglobin, creatine kinase-MB, and cardiac troponin I can rule out an AMI with greater than 96% accuracy. A b-type natriuretic peptide level less than 80 pg/mL can confidently rule out decompensated CHF with greater than 99% accuracy. However, no literature was found analyzing the use of these biomarkers in combination. A dyspnea biomarker panel could rapidly and accurately assist a clinician to rule out PE, AMI, and CHF. If a PE, AMI, or CHF is determined to be the cause of dyspnea, a biomarker panel could help risk stratify and help determine initial therapies. Subsequent clinical research is needed to corroborate this postulation.