Test Bench for Right Ventricular Failure Reversibility: The Hybrid BiVAD Concept

BACKGROUND

When heart transplantation and myocardial recovery are unlikely, patients presenting with biventricular cardiogenic shock initially treated with extracorporeal membrane oxygenation (ECMO) may benefit from a mechanical support upgrade. In this scenario, a micro-invasive approach is proposed: the combination of the double-lumen ProtekDuo cannula (Livanova, London, UK) and the Impella 5.5 (Abiomed, Danvers, MA) trans-aortic pump that translates into a hybrid BiVAD.

METHODS

All consecutive ECMO patients presenting with biventricular cardiogenic shock and ineligibility to heart transplantation from August 2022 were prospectively enrolled. The clinical course, procedural details, and in-hospital events were collected via electronic medical records.

RESULTS

A total of three patients, who were temporarily not eligible for heart transplantation or durable LVAD due to severe acute pneumonia and right ventricular (RV) dysfunction, were implanted with a hybrid BiVAD. This strategy provided high-flow biventricular support while pulmonary function ameliorated. Moreover, by differentially sustaining the systemic and pulmonary circulation, it allowed for a more adequate reassessment of RV function. All the patients were considered eligible for isolated durable LVAD and underwent less invasive LVAD implantation paired with a planned postoperative RVAD. In all cases, RV function gradually recovered and the RVAD was successfully removed.

CONCLUSIONS

The Hybrid BiVAD represents an up-to-date micro-invasive mechanical treatment of acute biventricular failure beyond ECMO. Its rationale relies on more physiological circulation across the lungs, the complete biventricular unloading, and the possibility of including an oxygenator in the circuit. Finally, the independent and differential control of pulmonary and systemic flows allows for more accurate RV function evaluation for isolated durable LVAD eligibility reassessment.

Choosing Between Left Ventricular Assist Devices and Biventricular Assist Devices

Right ventricular failure following left ventricular assist devices implantation is a serious complication associated with high mortality. In patients with or at high risk of developing right ventricular failure, biventricular support is recommended. Because univentricular support is associated with high survival rates, biventricular support is often undertaken as a last resort. With the advent of newer right ventricular and biventricular systems under design and testing, better differentiation is required to ensure optimal patients care. Clear guidelines on patient selection, time of intervention and device selection are required to improve patient outcomes.

The neutrophil to lymphocyte ratio in patients supported with extracorporeal membrane oxygenation

INTRODUCTION

The neutrophil to lymphocyte ratio (NLR) has proven to be a robust predictor of mortality in a wide range of cardiovascular diseases. This study investigated the predictive value of the NLR in patients supported by extracorporeal membrane oxygenation (ECMO) systems.

METHODS

This study included 107 patients who underwent ECMO implantation for cardiogenic shock. Median preoperative NLR was used to divide the cohort, with Group 1 NLR <14.2 and Group 2 with NLR ≥14.2. Survival, the primary outcome, was compared between groups.

RESULTS

The study cohort was composed of 64 (60%) males with an average age 53.1 ± 14.9 years. Patients in Group 1 had an average NLR of 7.5 ± 3.5 compared to 27.1 ± 19.9 in Group 2. Additionally, those in Group 2 had significantly higher preoperative blood urea nitrogen (BUN) and age. Survival analysis indicated a thirty-day survival of 56.2%, with significantly worsened mortality in patients with NLR greater than 14.2, p=0.047.

DISCUSSION

Our study shows the NLR has prognostic value in patients undergoing ECMO implantation. Leukocytes are known contributors to myocardial damage and neutrophil infiltration is associated with damage caused by myocardial ischemia.

The Sodium Paradox: Dysnatremia and Mortality in Patients Implanted With Extracorporeal Mechanical Circulatory Support Devices

INTRODUCTION

Dysnatremia, abnormal serum sodium levels, has long been used as a marker for disease progression in heart failure patients. Classically, hyponatremia is associated with increased fluid volume in heart failure and is often a result of neuroendocrine dysfunction and poor cardiac output. Recent studies have noted that dysnatremia and hypernatremia are predictive of worsened outcomes in critical care and renal disease populations. We investigated the relationship between dysnatremia and postoperative outcomes in patients implanted with extracorporeal mechanical circulatory devices.

METHODS

A total of 97 patients who underwent implantation with the CentriMag mechanical circulatory assist system were included in this retrospective study. Patients were divided into 2 groups based on preoperative serum sodium level cutoff of 135 mEq/L. Outcomes and mortality were compared between groups.

RESULTS

The mean age for the study population was 56.21 ± 15.13 years, and 57 patients (58.8%) were male. The mean time on CentriMag support was 22.7 days. Patients with serum sodium levels ≤135 mEq/L were noted to have significantly worsened indicators of preoperative cardiac function. However, patients with serum sodium levels >135 mEq/L had significantly shorter postoperative survival ( P = .006). When entered into a multivariate Cox proportional hazards model, sodium was an independent predictor for increased risk of mortality (hazard ratio: 1.224; 95% confidence interval: 1.009-1.485; P = .040).

CONCLUSION

Our results indicate that elevated preoperative sodium in patients undergoing implantation of a temporary mechanical circulatory support system is predictive of worsened postoperative survival.