Background and objective: The respiratory or heart origin of dyspnea is not always easy to find out using the available diagnostic tools. Many patients present both heart and lung diseases that cause dyspnea. The role of hemosiderin-laden macrophages count (HC) in sputum in this context has not been well settled so far. The objective was to describe the prediction usefulness of HC in patients suffering from dyspnea of heart origin, and to find out if HC changed after administering treatment.
Patients and method: HC was analyzed in 61 patients whose main symptom was dyspnea in the emergency department, and it was evaluated by means of clinical history, clinical course and performance of lung function tests and echocardiography.
Results: 35 patients were classified as having dyspnea of heart origin, 17 as having dyspnea of lung origin and 9 had dyspnea of both origins. The HC was higher in patients with dyspnea of heart origin 37% (95% CI, 26-47) or cardiopulmonary origin 30% (95% CI, 8-52) than in patients with dyspnea of lung origin 15% (95% CI, 4-27), and it remained higher despite administering treatment. The sensitivity (52%), specificity (88%), positive predictive value (92%) and negative predictive value (58%) was established for a 30% HC cutoff. The prediction model of heart origin dyspnea presented an area under the ROC curve of 0.978 (95% CI, 0.95-1).
Conclusions: HC reflects the severity of pulmonary venocapillar disturbance, identifies the majority of patients suffering from current or past heart failure or severe cardiac dysfunction, and is useful for the prediction of dyspnea of heart origin. HC utility should focus on selected patients.