A combination of bedside lung ultrasound and left ventricular outflow tract velocity time integral reclassifies early SCAI Shock staging and mortality risk in patients with STEMI

Background Cardiogenic shock (CS) historically complicates 5-15% of acute myocardial infarction (AMI). The most recent Society for Cardiovascular Angiography and Interventions (SCAI) Shock Classification (SSC) update combines physical examination , biochemical markers, and hemodynamic parameters to classify patients from progressively severe shock stages A-E. LUV classification, which combines LUS and LVOT-VTI measurement, evaluates important hemodynamic parameters in CS, and further improves prognostication in this setting. We sought to evaluate whether the rapid point-of-care LUV classification may help reclassify SSC and better early identify SSC A and B patients at risk in-hospital mortality. Methods This was a sinle-center, prospective cohort study conducted in a tertiary hospital in Brazil between July 2022 and February 2024. Patients eligible for inclusion were consecutive adults admitted with STEMI. LUS, LVOT-VTI, and SSC were obtained within 24 hours of hospital admission. LUS combined with LVOT-VTI (LUV) measurement was utilized to classify patients according to hemodynamic and congestion status. Patients were grouped into four profiles based on LUS and LVOT-VTI findings. LUV classification profiles were determined by: 1) evidence of lung congestion as defined by ≥3 positive zone scans and 2) evidence of hypoperfusion as defined by a low velocity time integral ≤14 cm. LUV classification A was defined as absence of lung congestion and high VTI; LUV classification B as presence of lung congestion and high LVOT-VTI; LUV classification C as absence of lung congestion and low VTI; and LUV classification D was defined as presence of lung congestion and low LVOT-VTI. The combined SCAI-LUV Classification definition is shown in Figure 1. Results We included 457 patients with mean age of 61.5 and 34.4% females. Prevalence of SSC A-E was 71.8%, 13.1%, 12.6%, 1.4%, and 0.74% respectively. Prevalence of SCAI LUV Classification A-E was 58.2%, 16.4%, 23.1%, 1.4%, and 0.74% respectively. In-hospital mortality was observed in 38 (9.4%) of patients, and there was an incremental increase in mortality with worsening SSC (A, 2.7%; B, 7.5%; C, 39.2%; D, 66.6%; E, 66.6%) and SCAI-LUV Classification (A, 0.85%; B, 1.5%; C, 31.1%; D, 66.6%; E, 66.6%). SSC and SCAI-LUV Classification area under the receiving operating characteristic (ROC) curves (AUC) for in-hospital mortality were 0.823 and 0.884, respectively. When we consider only 376 patients with SSC A and B, the AUCs were 0.621 and 0.877, respectively, with a net reclassification index of 0.106. Conclusion In the present analysis, use of the non-invasive LUV method reclassified SSC risk in 10.6% of patients with CS stages A and B. Efforts should be made to incorporate noninvasive point-of-care ultrasound into initial CS evaluations, to rapidly identify higher-risk CS patient and better tailor early initial and escalation pharmacologic and device-based therapies.SCAI-LUV Classification definition.