Mildly Elevated Pulmonary Artery Systolic Pressure is Associated with Extracorporeal Membrane Oxygenation Support after Heart Transplantation

Background. Pulmonary hypertension is a well-known risk factor for hemodynamic instability after heart transplantation. However, it remains unclear whether a mild elevation of pulmonary artery systolic pressure (PASP) is associated with higher risks of graft dysfunction and resultant extracorporeal membrane oxygenation (ECMO) support. Methods. From 2016 to 2021, 102 adult recipients undergoing orthotopic heart transplantation at our institution were investigated (mean age, 48.5 ± 13.2 years; 22.5% female). This study cohort was stratified into 3 groups based on the PASP measured by right heart catheterization before surgery: >50 mmHg, 35–50 mmHg, and <35 mmHg. The primary end point was ECMO support after procedure. Results. ECMO was implemented in 24 (23.5%) patients due to difficult weaning from cardiopulmonary bypass or cardiac low output in the intensive care unit, which was likely to be associated with higher mortality ( $P=0.053$ ). Age, gender, comorbidities, preoperative medications, and graft ischemia time were comparable across the 3 groups. The use of ECMO was significantly more common in patients with baseline PASP >50 mmHg (11/36, 30.6%) and 35–50 mmHg (12/38, 31.6%), while only 1 (3.6%) patient with baseline PASP <35 mmHg required ECMO support after transplant ( $P=0.007$ ). Multivariate logistic models demonstrated that PASP (odds ratio = 2.34; $P=0.028$ ) and cardiopulmonary bypass time (odds ratio = 1.01; $P<0.001$ ) were independent risk factors for postoperative ECMO. Conclusions. A mild elevation of pretransplant PASP (e.g., 35–50 mmHg) is related to low cardiac output and subsequent ECMO after heart transplantation, for which prompt administration of vasodilators before transplant may be protective.

Marginal versus Standard Donors in Heart Transplantation: Proper Selection Means Heart Transplant Benefit

BACKGROUND

In this study, we assessed the mid-term outcomes of patients who received a heart donation from a marginal donor (MD), and compared them with those who received an organ from a standard donor (SD).

METHODS

All patients who underwent HTx between January 2012 and December 2020 were enrolled at a single institution. The primary endpoints were early and long-term survival of MD recipients. Risk factors for primary graft failure (PGF) and mortality in MD recipients were also analyzed. The secondary endpoint was the comparison of survival of MD versus SD recipients.

RESULTS

In total, 238 patients underwent HTx, 64 (26.9%) of whom received an organ from an MD. Hospital mortality in the MD recipient cohort was 23%, with an estimated 1 and 5-year survival of 70% (59.2-82.7) and 68.1% (57.1-81), respectively. A multivariate analysis in MD recipients showed that decreased renal function and increased inotropic support of recipients were associated with higher mortality (p = 0.04 and p = 0.03). Cold ischemic time (p = 0.03) and increased donor inotropic support (p = 0.04) were independent risk factors for PGF. Overall survival was higher in SD than MD (85% vs. 68% at 5 years, log-rank = 0.008). However, risk-adjusted mortality (p = 0.2) and 5-year conditional survival (log-rank = 0.6) were comparable.

CONCLUSIONS

Selected MDs are a valuable resource for expanding the cardiac donor pool, showing promising results. The use of MDs after prolonged ischemic times, increased inotropic support of the MD or the recipient and decreased renal function are associated with worse outcomes.

Obesity is not a contraindication to veno-arterial extracorporeal life support

OBJECTIVES

Obesity may complicate the peripheral cannulation and delivery of veno-arterial extracorporeal life support (ECLS). With rising global body mass indices (BMI), obesity is becoming increasingly prevalent in severe cardiogenic shock yet its impact on outcomes is not well described. This study sought to examine the relationship between BMI and veno-arterial ECLS outcomes to better inform clinical decision-making.

METHODS

All cardiogenic shock patients undergoing peripheral veno-arterial ECLS at our institution from March 2008 to January 2019 were retrospectively analysed (n = 431). Patients were divided into 4 groups, BMI 17.5-24.9, 25-29.9, 30-34.9 and ≥35 kg/m2, and compared on clinical outcomes. Multivariable logistic regression was performed to identify variables associated with survival to discharge, the primary outcome of interest.

RESULTS

The median BMI was 28.3 kg/m2 (interquartile range 24.8-32.6) with a range of 17.0-69.1 kg/m2. Obese patients achieved significantly lower percentages of predicted flow rates compared with BMI < 25 kg/m2 patients though did not differ in their lactate clearances. Patients with BMI ≥35 kg/m2 had similar complication rates to the other cohorts but were more likely to require continuous veno-venous haemodialysis (51% vs 25-40% in other cohorts, P = 0.002). Overall survival to discharge was 48% (n = 207/431) with no differences between the cohorts (P = 0.92). Patients with BMI ≥35 kg/m2 had considerably lower survival (10%) in extracorporeal membrane oxygenation cardiopulmonary resuscitation compared with the other groups (P = 0.17). On multivariable logistic regression, BMI was not significantly associated with failure to survive to discharge.

CONCLUSIONS

In conclusion, with the rising global prevalence of obesity, the results of our study suggest that clinicians need not treat obesity as a negative prognostic factor in cardiogenic shock requiring ECLS.

Incidence and impact of primary graft dysfunction in adult heart transplant recipients: A systematic review and meta-analysis

PURPOSE

Primary graft dysfunction (PGD) is a leading cause of early mortality after heart transplant (HTx). To identify PGD incidence and impact on mortality, and to elucidate risk factors for PGD, we systematically reviewed studies using the ISHLT 2014 Consensus Report definition and reporting the incidence of PGD in adult HTx recipients.

METHODS

We conducted a systematic search in January 2020 including studies reporting the incidence of PGD in adult HTx recipients. We used a random effects model to pool the incidence of PGD among HTx recipients and, for each PGD severity, the mortality rate among those who developed PGD. For prognostic factors evaluated in ≥2 studies, we used random effects meta-analyses to pool the adjusted odds ratios for development of PGD. The GRADE framework informed our certainty in the evidence.

RESULTS

Of 148 publications identified, 36 observational studies proved eligible. With moderate certainty, we observed pooled incidences of 3.5%, 6.6%, 7.7%, and 1.6% and 1-year mortality rates of 15%, 21%, 41%, and 35% for mild, moderate, severe and isolated right ventricular-PGD, respectively. Donor factors (female sex, and undersized), recipient factors (creatinine, and pre-HTx use of amiodarone, and temporary or durable mechanical support), and prolonged ischemic time proved associated with PGD post-HTx.

CONCLUSION

Our review suggests that the incidence of PGD may be low but its risk of mortality high, increasing with PGD severity. Prognostic factors, including undersized donor, recipient use of amiodarone pre-HTx and recipient creatinine may guide future studies in exploring donor and/or recipient selection and risk mitigation strategies.

Can levosimendan reduce ECMO weaning failure in cardiogenic shock?: a cohort study with propensity score analysis

Background

Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) has been increasingly used over the last decade in patients with refractory cardiogenic shock. ECMO weaning can, however, be challenging and lead to circulatory failure and death. Recent data suggest a potential benefit of levosimendan for ECMO weaning. We sought to further investigate whether the use of levosimendan could decrease the rate of ECMO weaning failure in adult patients with refractory cardiogenic shock.

Methods

We performed an observational single-center cohort study. All patients undergoing VA-ECMO from January 2012 to December 2018 were eligible and divided into two groups: group levosimendan and group control (without levosimendan). The primary endpoint was VA-ECMO weaning failure defined as death during VA-ECMO treatment or within 24 h after VA-ECMO removal. Secondary outcomes were mortality at day 28 and at 6 months. The two groups were compared after propensity score matching. P < 0.05 was considered statistically significant.

Results

Two hundred patients were analyzed (levosimendan group: n = 53 and control group: n = 147). No significant difference was found between groups on baseline characteristics except for ECMO duration, which was longer in the levosimendan group (10.6 ± 4.8 vs. 6.5 ± 4.7 days, p < 0.001). Levosimendan administration started 6.6 ± 5.4 days on average following ECMO implantation. After matching of 48 levosimendan patients to 78 control patients, the duration of ECMO was similar in both groups. The rate of weaning failure was 29.1% and 35.4% in levosimendan and control groups, respectively (OR: 0.69, 95%CI: 0.25–1.88). No significant difference was found between groups for all secondary outcomes.

Conclusion

Levosimendan did not improve the rate of successful VA-ECMO weaning in patients with refractory cardiogenic shock.

Trial registration

ClinicalTrials.gov, NCT04323709.

A case series: the outcomes, support duration, and graft function recovery after VA-ECMO use in primary graft dysfunction after heart transplantation

Primary graft dysfunction (PGD) is a rare complication associated with high mortality after heart transplantation, which may require veno-arterial extra-corporeal membrane oxygenation (VA-ECMO) support. A standardized definition for PGD was developed by the International Society of Heart and Lung Transplantation in 2014. Due to limited reports using this definition, the detailed outcomes after VA-ECMO support remain unclear. Therefore, we retrospectively analyzed our single-center outcomes of PGD following VA-ECMO support. Between September 2014 and August 2018, 160 patients underwent heart transplantation in our single center. Nine PGD patients required VA-ECMO support, with an incidence of 5.6%. Pre-operative recipient/donor demographics, intra-operative variables, timing of VA-ECMO initiation and support duration, graft function recovery during 30 days after heart transplant, VA-ECMO complications, and survival were analyzed. The indication for VA-ECMO support was biventricular failure for all nine patients. Six patients had severe PGD requiring intra-operative VA-ECMO, while two patients had moderate PGD and one patient had mild PGD requiring post-operative VA-ECMO. All cohorts were successfully decannulated in a median of 10 days. Survival to discharge rate was 88.9%. One-year survival rate was 85.7%. Left ventricular ejection fraction recovered to normal within 30 days in all PGD patients. Our study showed VA-ECMO support led to high survival and timely graft function recovery in all cohorts. Further larger research can clarify the detailed effects of VA-ECMO support which may lead to standardized indication of VA-ECMO support for PGD patients.