Proportional Pulmonary Artery Pulse Pressure Identifies Hemodynamic Response to Impella: Conceptualization and Clinical Validation

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<h3>Purpose</h3> <b>1.</b> To describe the physiologic determinants of proportional pulmonary artery pulse pressure (= ratio of pulmonary pulse pressure to mean pulmonary pressure, PP-MPAP) <b>2.</b> clinical application of PP-MPAP in patients with cardiogenic shock (CS) who underwent left-sided Impella support. <h3>Methods</h3> <b>1.</b> Using established physiologic concepts and prior data, the change in PP-MPAP a was modelled over a range of hemodynamic parameters (Matlab, Mathworks). <b>2.</b> 16 patients with CS who underwent Impella support were included. Hemodynamic responder was defined as increase in cardiac power output index (CPOi)>20%. Clinical endpoint was lactate clearance 12 hours after Impella support. <h3>Results</h3> <b>1.</b> The relationship between stroke volume at different heart rates and PAWP was modelled [FIGURE]. <b>2.</b> 16 patients were included (age: 50±7 years; 13/16 males; 9/16 acute MI; 7/16 cardiomyopathy; LVEF: 17±4%). Impella reduced PAWP in all patients, but only 6/16 patients were responders. As predicted by the model, PP-MPAP increased in responders but dropped in non-responders. The increase in PP-MPAP correlated with increase in CPOi. The 10 non-responders were escalated to Ecpella (3(2-5)hours post-Impella), which increased PP-MPAP [TABLE]. 12-hour lactate clearance was greater in responders despite escalation to Ecpella in non-responders. Post-support PP-MPAP and the change in PP-MPAP were significantly associated with 12-hour lactate clearance. <h3>Conclusion</h3> PP-MPAP has a predictable relationship with stroke volume, and can identify hemodynamic responders to Impella, who had higher 12-hour lactate clearance.