Con: Patients Receiving Venoarterial Extracorporeal Membrane Oxygenation Should Not Always Have a Left Ventricular Vent Placed

Clinical predictors of in-hospital mortality in venoarterial extracorporeal membrane oxygenation

INTRODUCTION

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is utilized as a life-saving procedure and bridge to myocardial recovery for patients in refractory cardiogenic shock. Despite technical advancements, VA-ECMO retains high mortality. This study aims to identify the clinical predictors of in-hospital mortality after VA-ECMO to improve risk stratification for this tenuous patient population.

METHODS

The REgistry for Cardiogenic Shock: Utility and Efficacy of Device Therapy database is a multicenter, observational registry of ECMO patients. From 2013 to 2018, 789 patients underwent VA-ECMO. Bivariate analysis was performed on more than 300 variables regarding their association with in-hospital mortality. Logistic regression analyses were performed with variables chosen based upon clinical and statistical significance in the bivariate analysis. Tests were considered significant at a two-sided P < .05.

RESULTS

Although 63.5% patients were successfully weaned from VA-ECMO, in-hospital mortality was 57.9%. Nonsurvivors were older (P < .0001), had higher body mass index (P = .01), higher rates of hypertension (P = .02), coronary artery disease (P = .02), chronic obstructive pulmonary disease (P = .02), chronic liver disease (P = .008), percutaneous coronary intervention (P = .02), and surgical revascularization (P = .02). Multivariate predictors for in-hospital mortality include older age (odds ratio [OR], 1.019; P = .007), cardiac arrest (OR, 2.76; P = .006), chronic liver disease (OR, 8.87; P = .04), elevated total bilirubin (OR, 1.093; P < .0001), and the presence of a left ventricular vent (OR, 2.018; P = .03). Pre-ECMO sinus rhythm was protective (OR, 0.374; P = .006).

CONCLUSIONS

In a large study of recent VA-ECMO patients, in-hospital mortality remains significant, but acceptable given the severe pathology manifested in this population. Identification of pre-ECMO predictors of mortality helps stratify high-risk patients when deciding on ECMO placement, prolonged support, and prognosis.

Thrombotic risk in central venoarterial extracorporeal membrane oxygenation post cardiac surgery

Introduction:

Post-cardiotomy cardiogenic shock is an accepted indication for venoarterial extracorporeal membrane oxygenation. The true incidence and risk factors for the development of thrombosis in this setting remain unclear.

Methods:

Patients supported with central venoarterial extracorporeal membrane oxygenation due to ventricular dysfunction precluding weaning from cardiopulmonary bypass were retrospectively identified. Electronic records from a single institution spanning a 4-year period from January 2015 to December 2018 were interrogated to assess the incidence of thrombosis. The relationship to exposures including intracardiac stasis and procoagulant usage was explored.

Results:

Twenty-four patients met the inclusion criteria and six suffered major intracardiac thrombosis. All cases of thrombosis occurred early, and none survived to hospital discharge. The lack of left ventricular ejection conferred a 46% risk of developing thrombosis compared to 0% if ejection was maintained (p = 0.0093). Aprotinin use was also associated with thrombus formation (p = 0.035). There were no significant differences between numbers of patients receiving other procoagulants when grouped by thrombosis versus no thrombosis.

Conclusion:

Stasis is the predominant risk factor for intracardiac thrombosis. This occurs rapidly and the outcome is poor. As a result, we suggest early left ventricular decompression. Conventional management of post-bypass coagulopathy seems safe if the aortic valve is opening.

Impact of Left Atrial Decompression on Patient Outcomes During Pediatric Venoarterial Extracorporeal Membrane Oxygenation: A Case-Control Study

Left heart distension during venoarterial extracorporeal membrane oxygenation (VA ECMO) often necessitates decompression to facilitate myocardial recovery and prevent life-threatening complications. The objectives of this study were to compare clinical outcomes between patients who did and did not undergo left atrial (LA) decompression, quantify decompression efficacy, and identify risk factors for development of left heart distension. This was a single-center retrospective case-control study. Pediatric VA ECMO patients who underwent LA decompression from June 2004 to March 2016 were identified, and a control cohort of VA ECMO patients who did not undergo LA decompression were matched based on diagnosis, extracorporeal cardiopulmonary resuscitation, and age. Among 194 VA ECMO cases, 21 (11%) underwent LA decompression. Compared to the control cohort, patients with decompression had longer hospital length of stay (60 ± 55 vs. 27 ± 23 days, p = 0.012), but similar in-hospital mortality (29% vs. 38%, p = 0.513). Decompression successfully decreased mean LA pressure (24 ± 11 to 14 ± 4 mmHg, p = 0.022) and LA:RA pressure gradient (10 ± 7 to 0 ± 1 mmHg, p = 0.011). No significant differences in early quantitative measures of cardiac function were observed between cases and controls to identify risk factors for left heart distension. Despite higher qualitative risk for impaired cardiac recovery, patients who underwent LA decompression had comparable outcomes to those who did not. Given that traditional quantitative measures of cardiac function are insufficient to predict development of eventual left heart distension, a combination of clinical history, radiographic findings, hemodynamic monitoring, and laboratory markers should be used during the evaluation and management of these patients.