Lung ultrasound in acute myocardial infarction. Updating Killip & Kimball

BACKGROUND: Heart failure complicating acute myocardial infarction marks an ominous prognosis. Killip and Kimball's classification of heart failure remains a useful tool in these patients. Lung ultrasound can detect pulmonary congestion but its usefulness in this scenario is unknown. OBJECTIVE: To investigate the diagnostic accuracy of lung ultrasound to predict heart failure in patients with acute myocardial infarction. METHODS: Patients admitted with acute myocardial infarction and without heart failure were evaluated with a lung ultrasound. The presence of B-lines was recorded and counted. The presence of new heart failure (Killip Class B, C, or D) during hospitalization was evaluated by a cardiologist blinded to the results of lung ultrasound. A ROC curve analysis was done to evaluate the diagnostic accuracy of B-lines to predict heart failure. RESULTS: 200 patients were included. Three patients were diagnosed with cardiogenic shock, 5 with acute pulmonary edema, and 17 with mild heart failure. Patients who develop heart failure had a median of 14 B-lines, however, patients who remained in Killip class A had a median of 2 (p = 0,0001). The area under the ROC curve of the sum of B-lines to predict any form of heart failure was 0,91 (CI95% 86–97). The best cut-off value was 5 B-lines, with a sensitivity of 88% (IC95% 68,8–97,5) and specificity of 81% (IC95% 73,9–86,2). CONCLUSION: Lung ultrasound done at admission can help to predict heart failure In patients with acute myocardial infarction.