Midterm Outcomes of Bridge-to-Recovery Patients After Short-Term Mechanical Circulatory Support

The intra-aortic balloon pump as a rescue device: Do we need to shift our strategy for cardiogenic shock rescue after cardiac surgery?

OBJECTIVE

The intra-aortic balloon pump (IABP) is widely used to rescue patients from complications following cardiac surgery. Given improvements in rescue strategies over the past decade, the appropriateness of IABP must be reexamined. This study assessed the risk factors, outcomes, and predictors of survival of rescue IABP placement.

METHODS

Patients receiving an isolated rescue IABP during or after cardiac surgery from 2012 to 2020 were studied. All adult patients undergoing cardiac surgery except transplantation and primary mechanical circulatory support (MCS) procedures were included.

RESULTS

Of 10,591 patients, 397 (3.7%) received a perioperative IABP, including 182 (45.8%) with rescue IABP placement. The indications for rescue IABP were postcardiotomy shock (n = 66; 36.3%), failure to wean off cardiopulmonary bypass (n = 58; 31.9%), myocardial ischemia (n = 30; 16.5%), cardiac arrest (n = 25; 13.7%), and ventricular arrhythmia (n = 3; 1.6%). The in-hospital failure to rescue rate was 17.6% (n = 32 of 182) with a 90-day survival of 80.8% and 1-year survival of 76.9%. The most common etiology of mortality was ongoing cardiogenic shock (61.9%; n = 26 of 42). IABP use for >4 days and cardiac arrest as an indication for IABP were risk factors for 1-year mortality (adjusted hazard ratio, 2.68 [95% confidence interval (CI), 1.31-5.50] and 2.69 [95% CI, 1.11-6.54], respectively).

CONCLUSIONS

Rescue IABP following cardiac surgery is associated with increased early and 1-year mortality. Prolonged IABP use beyond 4 days or cardiac arrest as an indication portended a significantly worse prognosis. Rescue IABP may not be the optimal first-line temporary MCS for all patients, as the level of support provided might not match the severity of cardiogenic shock. Alternative MCS strategies should be considered early.

Recovery With Temporary Mechanical Circulatory Support While Waitlisted for Heart Transplantation

BACKGROUND

The 2018 U.S. heart allocation system offers an accelerated pathway for heart transplantation to the most urgent patients.

OBJECTIVES

This study sought to determine whether the new allocation system resulted in lower likelihood of candidate recovery.

METHODS

Adult patients waitlisted for heart transplantation with temporary mechanical circulatory support at the time of initial listing between 2010 and 2020 in the United Network for Organ Sharing registry were included. Competing events of heart transplantation, waitlist death or delisting for deteriorating condition, and delisting for improved condition (candidate recovery) were analyzed in the new vs old heart allocation system.

RESULTS

A total of 688 patients were waitlisted with venoarterial extracorporeal membrane oxygenation or a surgical nondischargeable biventricular assist device (status 1 or old 1A). Overall, 2,237 patients were waitlisted with an intra-aortic balloon pump, a percutaneous left ventricular assist device (LVAD), or a surgical nondischargeable LVAD (status 2 or old 1A). Patients waitlisted with venoarterial extracorporeal membrane oxygenation or a nondischargeable biventricular assist device had significantly shorter median waitlist times (5 vs 31 days), higher incidence for cardiac transplantation (81.5% vs 43.0%), and lower incidence of candidate recovery (1.5% vs 7.9%) in the new vs old heart allocation system (all P < 0.05). Patients waitlisted with an intra-aortic balloon pump or percutaneous or a nondischargeable LVAD also had significantly shorter median waitlist times (8 vs 35 days), higher incidence of transplantation (88.9% vs 64.9%), and lower incidence of candidate recovery (0.2% vs 1.6%) in the new vs old heart allocation system (all P < 0.05).

CONCLUSIONS

Current practice of the new allocation system may not offer select temporary mechanical circulatory support patients the opportunity and adequate time to recover to the point of waitlist removal. Further research will determine which patients would benefit from urgent transplantation vs recovery strategy.

Proposal for a trial of early left ventricular venting during venoarterial extracorporeal membrane oxygenation for cardiogenic shock

Objective

Patients with profound cardiogenic shock may require venoarterial (VA) extracorporeal membrane oxygenation (ECMO) for circulatory support most commonly via the femoral vessels. The rate of cardiac recovery in this population remains low, possibly because peripheral VA-ECMO increases ventricular afterload. Whether direct ventricular unloading in peripheral VA-ECMO enhances cardiac recovery is unknown, but is being more frequently utilized. A randomized trial is warranted to evaluate the clinical effectiveness of percutaneous left ventricle venting to enhance cardiac recovery in the setting of VA-ECMO.

Methods

We describe the rationale, design, and initial testing of a randomized controlled trial of VA-ECMO with and without percutaneous left ventricle venting using a percutaneous micro-axial ventricular assist device.

Results

This is an ongoing prospective randomized controlled trial in adult patients with primary cardiac failure presenting in cardiogenic shock requiring peripheral VA-ECMO, designed to test the safety and effectiveness of percutaneous left ventricle venting in improving the rate of cardiac recovery.

Conclusions

The results of this nonindustry-sponsored trial will provide critical information on whether left ventricle unloading in peripheral VA-ECMO is safe and effective.