Q91 / 110
In the 2022 SCAI SHOCK update, the cardiac arrest ("A") modifier is most appropriately applied to which patient?
Correct answer: B — A patient with a prolonged cardiac arrest, GCS <8 after ROSC, requiring ongoing resuscitative efforts
The cardiac arrest modifier applies to patients who have experienced a cardiac arrest requiring cardiopulmonary resuscitation and/or defibrillation — particularly when accompanied by ongoing neurologic impairment (e.g., GCS <8) — reflecting a more hemodynamically and neurologically significant event. A brief arrhythmia terminated by a single defibrillation without CPR, in a patient with normal neurologic function, does not trigger the modifier. Cardiac arrest at any SCAI stage independently increases mortality (adjusted OR 3.99). This distinction is clinically important because it affects both prognostication and candidacy for advanced therapies such as transplantation.
Board pearl: The cardiac arrest modifier reflects neurologic status and resuscitative burden, not simply the occurrence of an arrhythmia.
The cardiac arrest modifier applies to patients who have experienced a cardiac arrest requiring cardiopulmonary resuscitation and/or defibrillation — particularly when accompanied by ongoing neurologic impairment (e.g., GCS <8) — reflecting a more hemodynamically and neurologically significant event. A brief arrhythmia terminated by a single defibrillation without CPR, in a patient with normal neurologic function, does not trigger the modifier. Cardiac arrest at any SCAI stage independently increases mortality (adjusted OR 3.99). This distinction is clinically important because it affects both prognostication and candidacy for advanced therapies such as transplantation.
Board pearl: The cardiac arrest modifier reflects neurologic status and resuscitative burden, not simply the occurrence of an arrhythmia.
Source(s): Naidu SS, Baran DA, Jentzer JC, et al. SCAI SHOCK Stage Classification Expert Consensus Update. J Am Coll Cardiol. 2022;79(9):933-946. doi:10.1016/j.jacc.2022.01.018. | Jentzer JC, van Diepen S, Barsness GW, et al. Cardiogenic Shock Classification To Predict Mortality in the Cardiac Intensive Care Unit. J Am Coll Cardiol. 2019;74(17):2117-2128. doi:10.1016/j.jacc.2019.07.077.
Q92 / 110
Which set of findings best supports readiness to begin de-escalating temporary MCS in a patient with SCAI stage C-to-D cardiogenic shock who has been on device support for several days?
Correct answer: B — Resolution of end-organ dysfunction, improving contractility on echocardiography, lactate ≤2 mmol/L, and minimal vasoactive support
The AHA scientific statement on tMCS escalation and de-escalation recommends initiating weaning when there is resolution of cardiac dysfunction or evidence of at least partial myocardial recovery, improvement in end-organ hypoperfusion, intravascular euvolemia, minimal intravenous inotropic support, and improved contractility on echocardiography. Daily assessments to determine readiness to wean are recommended, with the goal of explanting the device as soon as it is safe, because longer duration of support is associated with worse outcomes.
Board pearl: Weaning readiness is a multimodal assessment — no single metric is sufficient, and daily reassessment is recommended.
The AHA scientific statement on tMCS escalation and de-escalation recommends initiating weaning when there is resolution of cardiac dysfunction or evidence of at least partial myocardial recovery, improvement in end-organ hypoperfusion, intravascular euvolemia, minimal intravenous inotropic support, and improved contractility on echocardiography. Daily assessments to determine readiness to wean are recommended, with the goal of explanting the device as soon as it is safe, because longer duration of support is associated with worse outcomes.
Board pearl: Weaning readiness is a multimodal assessment — no single metric is sufficient, and daily reassessment is recommended.
Source(s): Geller BJ, Sinha SS, Kapur NK, et al. Escalating and De-Escalating Temporary Mechanical Circulatory Support in Cardiogenic Shock: A Scientific Statement From the AHA. Circulation. 2022;146(6):e50-e68. doi:10.1161/CIR.0000000000001076.
New — ECMO & Impella Weaning
Q93 / 110
A patient on VA-ECMO for postcardiotomy cardiogenic shock has been hemodynamically stable for 36 hours. Lactate is 1.4 mmol/L, creatinine is improving, vasopressors have been weaned to low-dose norepinephrine, and echocardiography shows improved biventricular contractility with aortic valve opening on every beat. Which next step is most appropriate?
Correct answer: B — Initiate a stepwise flow reduction trial with hemodynamic and echocardiographic monitoring
The AHA scientific statement recommends daily assessments to determine readiness to wean, and suggests initiating weaning when there is resolution of cardiac dysfunction, improvement in end-organ hypoperfusion, intravascular euvolemia, minimal inotropic support, and improved contractility on echocardiography. This patient meets all readiness-to-wean criteria. VA-ECMO flows are typically reduced in increments of 0.5 to 1 L/min until 1.5–2.0 L/min is reached, with continuous hemodynamic and echocardiographic monitoring throughout. Immediate decannulation without a weaning trial risks hemodynamic collapse. Prolonging full support unnecessarily increases device-related complications, as longer duration of support is associated with worse outcomes.
Board pearl: The AHA recommends daily readiness-to-wean assessments and weaning tMCS with the intention of explanting as soon as it is safe.
The AHA scientific statement recommends daily assessments to determine readiness to wean, and suggests initiating weaning when there is resolution of cardiac dysfunction, improvement in end-organ hypoperfusion, intravascular euvolemia, minimal inotropic support, and improved contractility on echocardiography. This patient meets all readiness-to-wean criteria. VA-ECMO flows are typically reduced in increments of 0.5 to 1 L/min until 1.5–2.0 L/min is reached, with continuous hemodynamic and echocardiographic monitoring throughout. Immediate decannulation without a weaning trial risks hemodynamic collapse. Prolonging full support unnecessarily increases device-related complications, as longer duration of support is associated with worse outcomes.
Board pearl: The AHA recommends daily readiness-to-wean assessments and weaning tMCS with the intention of explanting as soon as it is safe.
Source(s): Geller BJ, Sinha SS, Kapur NK, et al. Escalating and De-Escalating Temporary Mechanical Circulatory Support in Cardiogenic Shock: A Scientific Statement From the AHA. Circulation. 2022;146(6):e50-e68. doi:10.1161/CIR.0000000000001076.
Q94 / 110
During a VA-ECMO weaning trial at 2 L/min flow, which combination of echocardiographic findings best predicts successful decannulation?
Correct answer: B — LVOT VTI >10 cm, tissue Doppler lateral mitral annular S′ ≥6 cm/s, aortic valve opening every cycle, no RV dilation
Multiple studies and the EACTS/ELSO/STS/AATS expert consensus identify a cluster of echocardiographic parameters that predict successful VA-ECMO weaning at reduced flows: LVOT VTI >10–12 cm, tissue Doppler lateral mitral annular S′ ≥6 cm/s, LVEF >20–25%, aortic valve opening with each cardiac cycle, and absence of RV or LV distention or stasis. Alonso-Fernandez-Gatta et al. found LVEF >33.4% was the optimal cutoff for discriminating successful weaning (AUC 0.808), independently associated with survival to discharge. However, Tavazzi et al. found LVOT VTI >12.3 cm, MAPSE >8.9 mm, and TAPSE >16 mm predicted weaning success and survival, whereas LVEF did not independently predict weaning success at any time point — longitudinal function and native ejection (VTI) may be more reliable than LVEF alone.
Board pearl: LVOT VTI and longitudinal function parameters (S′, MAPSE, TAPSE) may be more reliable weaning predictors than LVEF alone — multiparametric assessment is essential.
Multiple studies and the EACTS/ELSO/STS/AATS expert consensus identify a cluster of echocardiographic parameters that predict successful VA-ECMO weaning at reduced flows: LVOT VTI >10–12 cm, tissue Doppler lateral mitral annular S′ ≥6 cm/s, LVEF >20–25%, aortic valve opening with each cardiac cycle, and absence of RV or LV distention or stasis. Alonso-Fernandez-Gatta et al. found LVEF >33.4% was the optimal cutoff for discriminating successful weaning (AUC 0.808), independently associated with survival to discharge. However, Tavazzi et al. found LVOT VTI >12.3 cm, MAPSE >8.9 mm, and TAPSE >16 mm predicted weaning success and survival, whereas LVEF did not independently predict weaning success at any time point — longitudinal function and native ejection (VTI) may be more reliable than LVEF alone.
Board pearl: LVOT VTI and longitudinal function parameters (S′, MAPSE, TAPSE) may be more reliable weaning predictors than LVEF alone — multiparametric assessment is essential.
Source(s): Randhawa VK, Al-Fares A, Tong MZY, et al. A Pragmatic Approach to Weaning Temporary Mechanical Circulatory Support. JACC Heart Fail. 2021;9(9):664-673. doi:10.1016/j.jchf.2021.05.011. | Lorusso R, Whitman G, Milojevic M, et al. 2020 EACTS/ELSO/STS/AATS Expert Consensus on Post-Cardiotomy Extracorporeal Life Support. J Thorac Cardiovasc Surg. 2021;161(4):1287-1331. doi:10.1016/j.jtcvs.2020.09.045. | Alonso-Fernandez-Gatta M, Merchan-Gomez S, Gonzalez-Cebrian M, et al. Echocardiographic Prediction of Successful Weaning From VA-ECMO. Am J Crit Care. 2022;31(6):483-493. doi:10.4037/ajcc2022588. | Tavazzi G, Colombo CNJ, Klersy C, et al. Echocardiographic Parameters for Weaning From ECMO. Eur Heart J Cardiovasc Imaging. 2025;26(2):359-367. doi:10.1093/ehjci/jeae274.
Q95 / 110
Which echocardiographic parameter measured during full VA-ECMO support has shown the best predictive performance for successful weaning compared with conventional LV-focused criteria?
Correct answer: C — Tricuspid annular S′/RVSP ratio >0.33
Kim et al. demonstrated that RV-pulmonary circulation (RV-PC) coupling metrics measured during full ECMO support significantly outperformed conventional echocardiographic criteria (LVEF >20%, LVOT VTI ≥10 cm, mitral annular S′ ≥6 cm/s) in predicting successful weaning. Among the RV-PC coupling parameters, tricuspid annular S′/RVSP >0.33 exhibited the best predictive value (AUC 0.695), followed by RV free-wall longitudinal strain/RVSP >0.45 and TAPSE/RVSP >0.45. Conventional criteria showed essentially no discriminatory ability at full ECMO flow. This is clinically important because RV function assessment under full support can identify weaning readiness without requiring potentially risky flow reduction trials.
Board pearl: RV-PC coupling metrics can be assessed at full ECMO flow, potentially avoiding the hemodynamic instability associated with repeated low-flow weaning trials.
Kim et al. demonstrated that RV-pulmonary circulation (RV-PC) coupling metrics measured during full ECMO support significantly outperformed conventional echocardiographic criteria (LVEF >20%, LVOT VTI ≥10 cm, mitral annular S′ ≥6 cm/s) in predicting successful weaning. Among the RV-PC coupling parameters, tricuspid annular S′/RVSP >0.33 exhibited the best predictive value (AUC 0.695), followed by RV free-wall longitudinal strain/RVSP >0.45 and TAPSE/RVSP >0.45. Conventional criteria showed essentially no discriminatory ability at full ECMO flow. This is clinically important because RV function assessment under full support can identify weaning readiness without requiring potentially risky flow reduction trials.
Board pearl: RV-PC coupling metrics can be assessed at full ECMO flow, potentially avoiding the hemodynamic instability associated with repeated low-flow weaning trials.
Source(s): Kim D, Park Y, Choi KH, et al. Prognostic Implication of RV Coupling to Pulmonary Circulation for Successful Weaning From ECMO. JACC Cardiovasc Imaging. 2021;14(8):1523-1531. doi:10.1016/j.jcmg.2021.02.018.