Predicting mortality in cardiogenic shock secondary to ACS requiring short-term mechanical circulatory support: The ACS-MCS score.

OBJECTIVE: To identify predictors of 30-day all-cause mortality for patients with cardiogenic shock secondary to acute coronary syndrome (ACS-CS) who require short-term mechanical circulatory support (ST-MCS). BACKGROUND: ACS-CS mortality is high. ST-MCS is an attractive treatment option for hemodynamic support and stabilization of deteriorating patients. Mortality prediction modeling for ACS-CS patients requiring ST-MCS has not been well-defined. METHODS: The Utah Cardiac Recovery (UCAR) Shock database was used to identify patients admitted with ACS-CS requiring ST-MCS devices between May 2008 and August 2018. Pre-ST-MCS clinical, laboratory, echocardiographic, and angiographic data were collected. The primary endpoint was 30-day all-cause mortality. A weighted score comprising of pre-ST-MCS variables independently associated with 30-day all-cause mortality was derived and internally validated. RESULTS: A total of 159 patients (mean age, 61 years; 78% male) were included. Thirty-day all-cause mortality was 49%. Multivariable analysis resulted in four independent predictors of 30-day all-cause mortality: age, lactate, SCAI CS classification, and acute kidney injury. The model had good calibration and discrimination (area under the receiver operating characteristics curve 0.80). A predictive score (ranging 0-4) comprised of age ≥ 60 years, pre-ST-MCS lactate ≥2.5 mmol/L, AKI at time of ST-MCS implementation, and SCAI CS stage E effectively risk stratified our patient population. CONCLUSION: The ACS-MCS score is a simple and practical predictive score to risk-stratify CS secondary to ACS patients based on their mortality risk. Effective mortality risk assessment for ACS-CS patients could have implications on patient selection for available therapeutic strategy options.

Safety of long-distance transfers of patients on acute mechanical circulatory support.

BACKGROUND: Acute mechanical circulatory support (aMCS) can be a lifesaving therapy for patients with refractory cardiogenic shock. As device safety and technology improve, so will the ability to extend aMCS to patients at remote hospitals. The Intermountain West is unique because of the large geographical area, making transport of critically ill patients a logistical challenge. METHODS: We reviewed our experience of transporting patients in cardiogenic shock over long distances who had already been placed on aMCS: Impella and extracorporeal membrane oxygenator devices. Survival data was compared to international benchmark data published by the Extracorporeal Life Support Organization. RESULTS: A total of 11 patients (91% male; mean age 56 ± 5.4 y) were transported via fixed-wing aircraft to our center. The etiology of cardiogenic shock was ST-elevation myocardial infarction (n = 4), acutely decompensated chronic systolic heart failure (n = 4), postcardiotomy shock (n = 2), and acute myocarditis (n = 1). Average transport distance was 364 ± 139 miles (585 ± 264 km) and flight time was 170 ± 29 min. All patients were safely transported with no in-transit adverse events. The average duration of aMCS was 6.4 ± 3.3 d. Six patients (54.5%) survived to device explantation and 3 (27.2%) survived to hospital discharge. For comparison, Extracorporeal Life Support Organization benchmark data for adult cardiogenic shock patients report 56% survival to device explantation and 41% to hospital discharge. CONCLUSIONS: Patient transport with aMCS over long distances can be done safely without serious adverse events using good protocols and well-trained personnel. Although survival data are slightly below benchmark data, they appear reasonable, given the severity of illness and challenges of transferring critically ill patients to an expert center.

Development and Implementation of a Comprehensive, Multidisciplinary Emergency Department Extracorporeal Membrane Oxygenation Program.

Despite advances in the medical and surgical management of cardiovascular disease, greater than 350,000 patients experience out-of-hospital cardiac arrest in the United States annually, with only a 12% neurologically favorable survival rate. Of these patients, 23% have an initial shockable rhythm of ventricular fibrillation/pulseless ventricular tachycardia (VF/VT), a marker of high probability of acute coronary ischemia (80%) as the precipitating factor. However, few patients (22%) will experience return of spontaneous circulation and sufficient hemodynamic stability to undergo cardiac catheterization and revascularization. Previous case series and observational studies have demonstrated the successful application of intra-arrest extracorporeal life support, including to out-of-hospital cardiac arrest victims, with a neurologically favorable survival rate of up to 53%. For patients with refractory cardiac arrest, strategies are needed to bridge them from out-of-hospital cardiac arrest to the catheterization laboratory and revascularization. To address this gap, we expanded our ICU and perioperative extracorporeal membrane oxygenation (ECMO) program to the emergency department (ED) to reach this cohort of patients to improve survival. In this report, we illustrate our process and initial experience of developing a multidisciplinary team for rapid deployment of ED ECMO as a template for institutions interested in building their own ED ECMO programs.

Effect of Portable, In-Hospital Extracorporeal Membrane Oxygenation on Clinical Outcomes.

The time between onset of cardiogenic shock and initiation of mechanical circulatory support is inversely related to patient survival as delays in transporting patients to the operating room (OR) for venoarterial extracorporeal membrane oxygenation (VA ECMO) could prove fatal. A primed and portable VA ECMO system may allow faster initiation of ECMO in various hospital locations and subsequently improve outcomes for patients in cardiogenic shock. We reviewed our institutional experience with VA ECMO based on two time periods: beginning of our VA ECMO program and from initiation of our primed and portable in-hospital ECMO system. The primary endpoint was patient survival to discharge. A total of 137 patients were placed on VA ECMO during the study period; n = 66 (48%) before and n = 71 (52%) after program initiation. In the second era, the proportion of OR ECMO initiation decreased significantly (from 92% to 49%, p < 0.01) as more patients received ECMO in other hospital units, including the emergency department (p < 0.01) and during cardiac arrest (12% vs. 38%, p < 0.01). Survival to hospital discharge was equivalent between the two groups (30% vs. 42%, p = 0.1) despite more patients being placed on ECMO during ongoing cardiac arrest. Finally, we observed increased clinical volume since initiation of the in-hospital, portable ECMO system. Developing an in-hospital, primed and portable VA ECMO program resulted in increased clinical volume with equivalent patient survival despite a sicker cohort of patients. We conclude that more rapid deployment of VA ECMO may extend the treatment eligibility to more patients and improve patient outcomes.

Exploratory analysis of myocardial function after extracorporeal cardiopulmonary resuscitation vs conventional cardiopulmonary resuscitation.

OBJECTIVE: Ventricular unloading is associated with myocardial recovery. We sought to evaluate the association of extracorporeal cardiopulmonary resuscitation (ECPR) on myocardial function after cardiac arrest. We conducted a retrospective exploratory analysis, comparing ejection fraction (EF) after adult cardiac arrest, between ECPR and conventional CPR. RESULTS: Among 1119 cases of cardiac arrest, 116 had an echocardiogram post-return of spontaneous circulation (ROSC) and were included. Thirty-eight patients had ≥ 2 echocardiograms. ECPR patients had differences in age, hypertension and chronic heart failure. ECPR patients had a lower EF post-ROSC (24% vs 45%; p < 0.01) and were more likely to undergo percutaneous coronary intervention (25% vs 3%; p < 0.01). In multivariate analysis, only ECPR use (ß-coeff: 10.4 [95% CI 3.68-17.13]; p < 0.01) independently predicted improved myocardial function. In this exploratory study, EF after cardiac arrest may be more likely to improve among ECPR patients than CCPR patients. Our methodology should be replicated to confirm or refute the validity of our findings.