Short-term mechanical circulatory support for severe primary graft dysfunction following orthotopic heart transplant

Mechanical circulatory support in severe primary graft dysfunction: Peripheral cannulation but not earlier implantation improves survival in heart transplantation

BACKGROUND

Primary graft dysfunction (PGD) still affects 2% to 28% of heart transplants (HT). Severe PGD requires mechanical circulatory support (MCS) and is the main cause of death early after HT. Earlier initiation has been suggested to improve prognosis but the best cannulation strategy is unknown.

METHODS

Analysis of all HT in Spain between 2010 and 2020. Early (<3 hours after HT) vs late initiation (≥3 hours after HT) of MCS was compared. Special focus was placed on peripheral vs central cannulation strategy.

RESULTS

A total of 2376 HT were analyzed. 242 (10.2%) suffered severe PGD, 171 (70.7%) received early MCS and 71 (29.3%) late MCS. Baseline characteristics were similar. Patients with late MCS had higher inotropic scores and worse renal function at the moment of cannulation. Early MCS had longer cardiopulmonary bypass times and late MCS was associated with more peripheral vascular damage. No significant differences in survival were observed between early and late implant at 3 months (43.82% vs 48.26%; log-rank p = 0.59) or at 1 year (39.29% vs 45.24%, log-rank p = 0.49). Multivariate analysis did not show significant differences favoring early implant. Survival was higher in peripheral compared to central cannulation at 3 months (52.74% vs 32.42%, log-rank p = 0.001) and 1 year (48.56% vs 28.19%, log-rank p = 0.0007). In the multivariate analysis, peripheral cannulation remained a protective factor.

CONCLUSIONS

Earlier MCS initiation for PGD was not superior, compared to a more conservative approach with deferred initiation. Peripheral compared to central cannulation showed superior 3-month and 1-year survival rates.

Six years of continuous mechanical circulatory support following chronic graft failure

Re-transplantation is the preferred treatment for patients with chronic heart transplant failure. If re-transplantation is not a viable option due to the patient's comorbidities, left ventricle assist device can be used as the destination treatment. An interdisciplinary approach with thorough follow-up can help in the early detection and treatment of complications associated with LVAD.

Risk factors for heart transplant survival with greater than 5 h of donor heart ischemic time

OBJECTIVE

Implantation of donor hearts with prolonged ischemic times is associated with worse survival. We sought to identify risk factors that modulate the effects of prolonged preservation.

METHODS

Retrospective review of the United Network for Organ Sharing database (2000-2018) to identify transplants with >5 (n = 1526) or ≤5 h (n = 35,733) of donor heart preservation. In transplanted hearts preserved for >5 h, Cox-proportional hazards identify modifiers for survival.

RESULTS

Compared to ≤5 h, transplanted patients with >5 h of preservation spent less time in status 1B (76 ± 160 vs. 85 ± 173 days, p = .027), more commonly had ischemic cardiomyopathy (42.3% vs. 38.3%, p = .002), and less commonly received a blood type O heart (45.4% vs. 50.8%, p < .001). Longer heart preservation time was associated with a higher incidence of postoperative stroke (4.5% vs. 2.5%, p < .001), and dialysis (16.4% vs. 10.6%, p < .001). Prolonged preservation was associated with a greater likelihood of death from primary graft dysfunction (2.8% vs. 1.5%, p < .001) but there was no difference in death from acute (2.0% vs. 1.7%, p = .402) or chronic rejection (2.0% vs. 1.9%, p = .618). In transplanted patients with >5 h of heart preservation, multivariable analysis identified greater mortality with ischemic cardiomyopathy etiology (hazard ratio [HR] = 1.36, p < 0.01), pre-transplant dialysis (HR = 1.84, p < .01), pre-transplant extracorporeal membrane oxygenation (ECMO, HR = 2.36, p = .09), and O blood type donor hearts (HR = 1.35, p < .01).

CONCLUSION

Preservation time >5 h is associated with worse survival. This mortality risk is further amplified by preoperative dialysis and ECMO, ischemic cardiomyopathy etiology, and use of O blood type donor hearts.

Overview of Veno-Arterial Extracorporeal Membrane Oxygenation (VA-ECMO) Support for the Management of Cardiogenic Shock

Cardiogenic shock accounts for ~100,000 annual hospital admissions in the United States. Despite improvements in medical management strategies, in-hospital mortality remains unacceptably high. Multiple mechanical circulatory support devices have been developed with the aim to provide hemodynamic support and to improve outcomes in this population. Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is the most advanced temporary life support system that is unique in that it provides immediate and complete hemodynamic support as well as concomitant gas exchange. In this review, we discuss the fundamental concepts and hemodynamic aspects of VA-ECMO support in patients with cardiogenic shock of various etiologies. In addition, we review the common indications, contraindications and complications associated with VA-ECMO use.

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.

Postoperative vasoactive inotropic score is predictive of outcomes in pediatric heart transplantation

Vasoactive inotrope score (VIS) is scarcely studied in pediatric orthotopic heart transplantation (pOHT). We conducted a retrospective review of pOHT (<21 years) recipients. Max VIS and mean VIS were calculated at 0-24 and 24-48 hours post-pOHT. Patients were divided into groups based on ISHLT guidelines: high (>10) and low (≤10). In our group (n = 104), patients with high max and mean VIS groups at 0-24 and 24-48 hours had longer bypass times (high: >130 minutes; low: <108 minutes; P < .05) and high max and mean VIS groups at 0-24 hours had longer ischemic times (high: >215 minutes; low: <192 minutes; P < .05). Patients with high max and mean VIS at 0-24 and 24-48 hours had longer hospital stay, ventilation, inotrope duration, more cardiac events, and acute kidney injury postoperatively (P < .05). High max VIS at 24-48 hours and high mean VIS at 24-48 hours had higher 3-year mortality (P = .04; P = .02). Multivariate analysis confirmed the association of VIS with short-term outcomes. However, VIS was not identified as an independent predictor of mortality. The ROC curve exhibits 10 as the ideal cutoff with area under the curve >0.8 for primary graft dysfunction (PGD).

Histidine-Tryptophan-Ketoglutarate Solution for Donor Heart Preservation Is Safe for Transplantation

BACKGROUND

Various solutions are used for donor heart preservation. We examined the outcomes in our heart transplant population where histidine-tryptophan-ketoglutarate (HTK) solution has been used for heart preservation since 2004.

METHODS

This was a retrospective review of the United Network for Organ Sharing (UNOS) database (2004-2016) comparing our heart transplant outcomes with other national centers. Propensity matching in a 1:3 ratio was performed to adjust for preoperative recipient variables.

RESULTS

After propensity matching comparing UNOS outcomes (n = 1080) with our institutional data (n = 360), there was no difference in matched preoperative variables. Donor hearts were similar for donor age, sex, donor-to-recipient size ratio, LVEF, and ischemic time. Our HTK cohort had a larger proportion with donor cardiac arrest (26.3% vs 6.1%, P < .001) and longer cardiac arrest duration (22.1 ± 16.0 vs 17.2 ± 14.0 minutes, P = .052). Our primary graft dysfunction (PGD) rate requiring mechanical support was 4.2% (n = 1). Postoperative mechanical support use for PGD included extracorporeal membrane oxygenation in 9 (60.0%), intraaortic balloon pump in 4 (26.7%), right ventricular assist device in 3 (20%), and biventricular assist device in 3 (20%). Overall survival at our institution was similar to the national average (P = .649). Survival at 1, 5, and 10 years with HTK was 92.2%, 81.3%, and 70.8%, and for the UNOS population was 91.6%, 80.3%, and 62.0%, respectively.

CONCLUSIONS

Use of HTK solution for donor hearts was associated with a low rate of severe PGD. Overall survival was not significantly different from other institutions using a variety of preservation solutions in the UNOS database during the same period. HTK solution is efficacious for preservation of donor hearts.

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.