Diagnosis of cardiogenic shock without the use of a pulmonary artery catheter

Abstract

BACKGROUND: Current diagnostic criteria for cardiogenic shock (CS) require the use of a pulmonary artery catheter (PAC), which is time-consuming and may cause complications. A set of simple yet accurate noninvasive diagnostic criteria would be of significant utility. METHODS: Candidate components for the Noninvasive Parameters for Assessment of Cardiogenic Shock (N-PACS) criteria were required to be objective, readily available, and noninvasive. Variables encompassing hypotension, hypoperfusion, predisposing conditions, and elevated intracardiac filling pressures were optimized versus a PAC-based standard in a retrospective developmental cohort of 122 patients with acute myocardial infarction (AMI). The finalized criteria were validated in a prospective cohort of coronary care unit patients in whom a PAC was placed for clinical indications. RESULTS: According to invasive criteria, CS was present in 32 of 217 consecutive patients undergoing PAC. Compared to the PAC-based standard, the N-PACS criteria had a sensitivity of 96.9% (95% confidence interval (CI) 82.0-99.8), specificity of 90.8% (95% CI 85.5-94.4), positive predictive value of 64.6% (95% CI 49.4-77.4), negative predictive value of 99.4% (95% CI 96.2-100), positive likelihood ratio of 10.5 (95% CI 6.7-16.7), negative likelihood ratio of 0.03 (95% CI 0.00-0.24), and diagnostic odds ratio of 306.4. Results were similar among patients with and without AMI. CONCLUSION: A simple, echocardiography-based set of noninvasive diagnostic criteria can be used to accurately diagnose CS.