Impact of Donor Hemodynamics on Recipient Survival in Heart Transplantation.

BACKGROUND: Heart transplantation is the gold-standard therapy for end-stage heart failure, but rates of donor-heart use remain low due to various factors that are often not evidence based. The impact of donor hemodynamics obtained via right-heart catheterization on recipient survival remains unclear. METHODS: The United Network for Organ Sharing registry was used to identify donors and recipients from September 1999-December 2019. Donor hemodynamics data were obtained and analyzed using univariate and multivariable logistical regression, with the primary endpoints being 1- and 5-year post-transplant survival. RESULTS: Of the 85,333 donors who consented to heart transplantation during the study period, 6573 (7.7%) underwent right-heart catheterization, of whom 5531 eventually underwent procurement and transplantation. Donors were more likely to undergo right-heart catheterization if they had high-risk criteria. Recipients who had donor hemodynamic assessment had 1- and 5-year survival rates similar to those without donor hemodynamic assessment (87% vs 86%, 1 year). Abnormal hemodynamics were common in donor hearts but did not impact recipient survival rates, even when risk-adjusted in multivariable analysis. CONCLUSIONS: Donors with abnormal hemodynamics may represent an opportunity to expand the pool of viable donor hearts.

The impact of changes in renal function during waitlist time on outcomes after heart transplantation.

BACKGROUND AND AIM: This study evaluated the impact of changes in renal function during the waitlist period on posttransplant outcomes of orthotopic heart transplantation (OHT). METHODS: The United Network for Organ Sharing registry was used to identify adult patients undergoing isolated OHT from 2010 to 2020. Patients were stratified by whether their National Kidney Foundation chronic kidney disease (CKD) stage improved, worsened, or remained unchanged between listing and transplantation. Univariate analysis and multivariable Cox regression were conducted to determine whether a change in estimated glomerular filtration rate (eGFR) or change in CKD stage predicted 1-year mortality after OHT. RESULTS: Of 22,746 patients, the majority of patients remained in the same CKD stage (59.6%), and the frequencies of patients progressing to improved (19.3%) and worsened (21.1%) CKD stages were similar. Temporary mechanical circulatory support (MCS) was associated with improved CKD stage and durable MCS with worsened CKD stage (p < .001). Post-OHT dialysis was most common in patients with worsened CKD stage (13.2%) and least common in the improved cohort (9.4%) (p < .001). Kaplan-Meier unadjusted 1-year survival rates after OHT were similar between CKD change groups (log-rank p = .197). Multivariable analysis demonstrated no risk-adjusted effect of change in eGFR (p = .113) or change in CKD stage (p = .076) on 1-year mortality after OHT. CONCLUSIONS: Approximately 20% of patients improve CKD stage and 20% worsen CKD stage between listing and OHT, with the remaining 60% having unchanged CKD stage. Worsening CKD stage predicts increased likelihood of post-OHT dialysis, but CKD stage change does not predict 1-year survival following OHT.

Early venoarterial extracorporeal membrane oxygenation improves outcomes in post-cardiotomy shock.

Post-cardiotomy shock (PCS) is associated with substantial morbidity and mortality. We reviewed our 12-year experience of venoarterial extracorporeal membrane oxygenation (VA-ECMO) therapy for PCS. Between July 2007 and June 2018, 156 consecutive patients underwent VA-ECMO for PCS. We retrospectively investigated patient characteristics, indications, and management to determine factors affecting outcomes. Secondary analysis was performed by dividing the cohort into Era 1 (2007-2012, n = 52) and Era 2 (2013-2018, n = 104) for comparison. After a median of 4.70 days (interquartile range [IQR] 2.76-8.53) of ECMO support, 72 patients (46.1%) survived to discharge. In-hospital mortality decreased in Era 2 from 75 to 43.3% (P < 0.001). Survivors were cannulated at lower serum lactate (5.3 [IQR 2.8-8.2] versus 7.5 [4.7-10.7], P = 0.003) and vasoactive-inotropic score (22.7 [IQR 11.3-35.5] versus 28.1 [IQR 20.8-42.5], P = 0.017). Patients in Era 2 were more frequently cannulated intraoperatively (63.5% versus 34.6%, P = 0.002), earlier in their hospital course, and at lower levels of serum lactate and vasoactive-inotropic score than in Era 1. Independent risk factors for mortality included increased age (odds ratio [OR] 1.06, P = 0.002), serum lactate at cannulation (OR 1.17, P = 0.009), and vasoactive-inotropic score (OR 1.04, P = 0.009). Bleeding and limb ischemia were less common in Era 2. Overall, outcomes of ECMO for PCS improved over the study period. The survival benefit appears to be associated with earlier ECMO initiation before prolonged hypoperfusion occurs.

Right Ventricular Contractility and Pulmonary Arterial Coupling After Less Invasive Left Ventricular Assist Device Implantation.

Right ventricular failure contributes significantly to morbidity and mortality after left ventricular assist device implantation. Recent data suggest a less invasive strategy (LIS) via thoracotomy may be associated with less right ventricular failure than conventional median sternotomy (CMS). However, the impact of these approaches on load-independent right ventricular (RV) contractility and RV-pulmonary arterial (RV-PA) coupling remains uncertain. We hypothesized that the LIS approach would be associated with preserved RV contractility and improved RV-PA coupling compared with CMS. We performed a retrospective study of patients who underwent durable, centrifugal left ventricular assist device implantation and had paired hemodynamic assessments before and after implantation. RV contractility (end-systolic elastance [Ees]), RV afterload (pulmonary effective arterial elastance [Ea]), and RV-PA coupling (Ees/Ea) were determined using digitized RV pressure waveforms. Forty-two CMS and 21 LIS patients were identified. Preimplant measures of Ees, Ea, and Ees/Ea were similar between groups. After implantation, Ees declined significantly in the CMS group (0.60-0.40, p = 0.008) but not in the LIS group (0.67-0.58, p = 0.28). Coupling (Ees/Ea) was unchanged in CMS group (0.54-0.59, p = 0.80) but improved significantly in the LIS group (0.58-0.71, p = 0.008). LIS implantation techniques may better preserve RV contractility and improve RV-PA coupling compared with CMS.

Milk of Calcium Causing a Case of Calcific Pericardial Effusion.

A 60-year-old man presented with heart failure symptoms and was found to have a calcified pericardial effusion consistent with "milk of calcium" and constrictive physiology. The patient received a pericardiectomy and has had favorable outcomes at his 1-year follow-up. There are minimal reports of calcific pericardial effusion with constrictive pathology.

Heart Transplantation for Peripartum Cardiomyopathy: Outcomes Over 3 Decades.

BACKGROUND: This study evaluated trends and outcomes of patients undergoing heart transplantation for peripartum cardiomyopathy (PPCM) over the past 3 decades. METHODS: The United Network for Organ Sharing registry was used to identify patients undergoing isolated heart transplantation between 1987 and 2020. Patients were stratified by the decade of transplantation. Overall survival was compared using Kaplan-Meier analysis, and risk-adjustment was performed using Cox proportional hazards modeling. RESULTS: A total of 76 009 heart transplantations occurred in the study period, including 20 352 female patients and 809 female patients with PPCM. The frequency of transplantation for PPCM increased over the study period (P = .015). Among female patients, PPCM was significantly associated with 1-year mortality compared with nonischemic cardiomyopathy (hazard ratio, 1.38; 95% CI, 1.11-1.69; P = .004). Among patients with PPCM, Black and Hispanic heart transplant recipients had increased 1-year posttransplant mortality risk compared with White recipients. On Kaplan-Meier survival analysis, early and midterm survival was significantly worse in patients with PPCM compared with other female patients. The 5-, 10-, and 15-year survivals in patients with PPCM were 66.5%, 49.0%, and 40.2% compared with 74.3%, 56.0%, and 37.5% in female heart transplant recipients with other heart failure diagnoses, respectively (P < .001). Survival improved significantly in patients who underwent heart transplantation for PPCM in the latest decade from 2010 to 2020 compared with earlier decades (P < .001), and this improvement was most marked for Black recipients. CONCLUSIONS: Patients who underwent heart transplantation for PPCM have a significantly elevated risk for 1-year mortality compared with other female transplant recipients. However, survival among these patients has improved in the last decade, particularly for Black transplant recipients.

Prolonged Ischemia Times for Heart Transplantation: Impact of the 2018 Allocation Change.

BACKGROUND: In 2018, the United Network for Organ Sharing implemented a change in heart allocation policy resulting in increased organ ischemia times in early analyses. This study evaluated the effect of ischemia time on 1-year mortality in the context of allocation policy changes implemented in 2006 and 2018. METHODS: The United Network for Organ Sharing registry was used to identify adults undergoing heart transplantation from 2000 to 2020. Patients were stratified by the allocation policy era in which they received a transplant (2000-June 2006, July 2006-October 2018, October 2018-2020) and by ischemia time, defined as normal (≤4 hours) and prolonged (>4 hours). One-year survival was estimated using Kaplan-Meier analysis. Cox regression was used to determine risk-adjusted hazards for ischemia time on 1-year mortality. RESULTS: There were 40 052 patients included for analysis. Ischemia times were normal in 32 585 (81.36%) and prolonged in 7467 (18.64%) patients. The proportion of transplantations with prolonged ischemia times increased with each subsequent policy era. After the 2018 policy change, 1-year survival was 90.92% with normal ischemia times vs 87.52% with prolonged ischemia times (P < .001). Ischemia time independently predicted 1-year mortality in each era with a hazard ratio of 1.20 per hour (P = .004) in the current era. CONCLUSIONS: Prolonged ischemia times occur in a minority of cases but are increasing in frequency. The independent risk of prolonged ischemia time on 1-year mortality persists despite advances in storage technology and should remain a consideration in donor-recipient matching.

Predictors of Survival and Ventricular Recovery Following Acute Myocardial Infarction Requiring Extracorporeal Membrane Oxygenation Therapy.

The use of venoarterial extracorporeal membrane oxygenation (VA-ECMO) following acute myocardial infarction with cardiogenic shock (AMI-CS) is increasing, but the ability to predict favorable outcomes with support remains limited. We retrospectively reviewed all patients with AMI-CS supported with VA-ECMO between December 2008 and June 2018. One hundred twenty-six patients received VA-ECMO for AMI-CS during the study period; of these, 39 (31.0%) experienced ventricular recovery and were discharged while 87 (69.0%) did not recover, with 71 (56.3%) dying in the hospital and 16 (12.7%) surviving to discharge with either left ventricular assist device or heart transplant. TIMI 3 flow in culprit artery (OR, 4.01; 95% CI, 1.25-12.77; p = 0.02), serum lactate (OR, 0.89; 95% CI, 0.80-0.99; p = 0.04), and prompt revascularization (OR, 3.39; 95% CI, 1.18-9.81; p = 0.02) were independent predictors of ventricular recovery. Four variables emerged as independent predictors of in-hospital mortality and were used to create the AMI-ECMO Risk Score: age >70 years, creatinine >1.5 mg/dL, serum lactate > 4.0 mmol/L, and lack of TIMI 3 flow in culprit artery. In patients supported with VA-ECMO for AMI-CS, prompt, successful revascularization, and lower serum lactate were associated with ventricular recovery while younger age, lower serum lactate, and creatinine, and successful revascularization were associated with survival to discharge. The AMI-ECMO risk score is a simple tool that can help risk stratify patients with AMI-CS being considered for VA-ECMO support.

Large Animal Model of Pumpless Arteriovenous Extracorporeal CO2 Removal Using Room Air via Subclavian Vessels.

End-stage lung disease (ESLD) causes progressive hypercapnia and dyspnea and impacts quality of life. Many extracorporeal support (ECS) configurations for CO2 removal resolve symptoms but limit ambulation. An ovine model of pumpless ECS using subclavian vessels was developed to allow for ambulatory support. Vascular grafts were anastomosed to the left subclavian vessels in four healthy sheep. A low-resistance membrane oxygenator was attached in an arteriovenous (AV) configuration. Device function was evaluated in each animal while awake and spontaneously breathing and while mechanically ventilated with hypercapnia induced. Sweep gas (FiO2 = 0.21) to the device was increased from 0 to 15 L/min, and arterial and postdevice blood gases, as well as postdevice air, were sampled. Hemodynamics remained stable with average AV shunt flows of 1.34 ± 0.14 L/min. In awake animals, CO2 removal was 3.4 ± 1.0 ml/kg/min at maximum sweep gas flow. Respiratory rate decreased from 60 ± 25 at baseline to 30 ± 11 breaths per minute. In animals with induced hypercapnia, PaCO2 increased to 73.9 ± 15.1. At maximum sweep gas flow, CO2 removal was 3.4 ± 0.4 ml/kg/min and PaCO2 decreased to 49.1 ± 6.7 mm Hg. Subclavian AV access is effective in lowering PaCO2 and respiratory rate and is potentially an effective ambulatory destination therapy for ESLD patients.

Achieving 12 Hour Normothermic Ex Situ Heart Perfusion: An Experience of 40 Porcine Hearts.

Although total body perfusion with extracorporeal life support (ECLS) can be maintained for weeks, individual organ perfusion beyond 12 hours has yet to be achieved clinically. Normothermic ex situ heart perfusion (ESHP) offers the potential for prolonged cardiac preservation. We developed an ESHP system to study the effect of perfusate variables on organ preservation, with the ultimate goal of extending organ perfusion for ≥24 hours. Forty porcine hearts were perfused for a target of 12 hours. Hearts that maintained electromechanical activity and had a <3× increase in vascular resistance were considered successful preservations. Perfusion variables, metabolic byproducts, and histopathology were monitored and sampled to identify factors associated with preservation failure. Twenty-two of 40 hearts were successfully preserved at 12 hours. Successful 12 hour experiments demonstrated lower potassium (4.3 ± 0.8 vs. 5.0 ± 1.2 mmol/L; p = 0.018) and lactate (3.5 ± 2.8 vs. 4.5 ± 2.9 mmol/L; p = 0.139) levels, and histopathology revealed less tissue damage (p = 0.003) and less weight gain (p = 0.072). Results of these early experiments suggest prolonged ESHP is feasible, and that elevated lactate and potassium levels are associated with organ failure. Further studies are necessary to identify the ideal perfusate for normothermic ESHP.