Acute kidney injury during extracorporeal life support in cardiogenic shock: Does flow matter?

BACKGROUND: This study examines the role of extracorporeal life support flow in the development of acute kidney injury in cardiogenic shock. METHODS: We performed a retrospective analysis of 465 patients placed on extracorporeal life support at our institution between January 2015 and December 2020 for cardiogenic shock. Flow index was calculated by dividing mean flow by body surface. Stages of acute kidney injury were determined according to Kidney Disease: Improving Global Outcomes (KDIGO) organization guidelines. RESULTS: There were 179 (38.5%) patients who developed acute kidney injury, 63.1% of which were classified as Stage 3--the only subgroup associated with 1-year mortality (hazard ratio = 2.03, p < .001). Risk of kidney injury increased up to a flow index of 1.6 L/min/m2, and kidney injury was more common among patients with flow index greater than 1.6 L/min/m2 (p = .034). Those with kidney injury had higher baseline lactate levels (4.4 vs 3.1, p = .04), and Stage 3 was associated wit higher baseline creatinine (p < .001). CONCLUSIONS: In our cohort, kidney injury was common and Stage 3 kidney injury was associated with worse outcomes compared to other stages. Low flow was not associated with increased risk of kidney injury. Elevated baseline lactate and creatinine among patients with acute kidney injury suggest underlying illness severity, rather than flow, may influence kidney injury risk.

Predictors of 1-year outcome after cardiac re-transplantation: Machine learning analysis.

BACKGROUND: As cardiac re-transplantation is associated with inferior outcomes compared with primary transplantation, allocating scarce resources to appropriate re-transplant candidates is important. The aim of this study is to elucidate the factors associated with 1-year mortality in cardiac re-transplantation using the random forests algorithm for survival analysis. METHODS: We retrospectively reviewed the United Network for Organ Sharing registry and identified all adult (> 17 years old) recipients who underwent cardiac re-transplantation between January 2000 and March 2020. The random forest algorithm on Cox modeling was used to calculate the variable importance (VIMP) of independent variables for contributing to 1-year mortality. RESULTS: A total of 1294 patients underwent cardiac re-transplantation. Of these, 137 patients were re-transplanted within 1 year of their first transplant, while 1157 patients were re-transplanted more than 1 year after their first transplant. One-year mortality was significantly higher for patients receiving early transplantation compared with those receiving late transplantation (Early 40.6% vs. Late 13.6%, log-rank P < .001). Machine learning analysis showed that total bilirubin (> 2 mg/dl) (VIMP, 2.99%) was an independent predictor of 1-year mortality after early re-transplant. High BMI (> 30.0 kg/m2 ) (VIMP, 1.43%) and ventilator dependence (VIMP, 1.47%) were independent predictors of 1-year mortality for the late re-transplantation group. CONCLUSION: Machine learning showed that optimal 1-year survival following cardiac re-transplantation was significantly related to liver function in early re-transplantation, and to obesity and preoperative ventilator dependence in late re-transplantation.

Impact of UNOS allocation policy changes on utilization and outcomes of patients bridged to heart transplant with intra-aortic balloon pump.

OBJECTIVE: Intra-aortic balloon pump (IABP) support may improve the hemodynamic profiles of patients in cardiogenic shock and bridge patients to heart transplant. In 2018, the United Network for Organ Sharing (UNOS) introduced new heart allocation criteria that increased the waitlist status of patients with IABPs to Status 2. This study assesses the impact of this change on IABP use and outcomes of patients with IABPs. METHODS: We queried the UNOS database for first adult heart transplant candidates with IABPs listed or transplanted before and after the UNOS policy changes (October 18, 2016-October 17, 2018, or October 18, 2018-September 4, 2020). We compared post-transplant survival and waitlist outcomes using Kaplan-Meier and Fine-Gray analyses. RESULTS: Two thousand three hundred fifty-eight patients met inclusion criteria. Utilization of IABPs for hemodynamic support increased by 338% in the two years after the policy change. Patients with IABPs listed after the policy change were more likely to receive a transplant and were transplanted more quickly (p < .001). Posttransplant survival was comparable before and after the policy change (p = .056), but non-transplanted patients were more likely to be delisted post-policy change (p < .001). CONCLUSION: The UNOS allocation criteria have benefited patients bridged with an IABP, given the higher transplant rate and shorter time to transplant.

Deep vein thrombosis and pulmonary embolism after heart transplantation.

INTRODUCTION: Venous thromboembolism (VTE), such as deep vein thrombosis (DVT) and pulmonary embolism (PE), is an important and serious postoperative complication after heart transplantation. We sought to characterize in-hospital VTE after heart transplantation and its association with clinical outcomes. METHOD: Adult (≧18 years) patients undergoing heart transplantation from 2015 to 2019 at our center were retrospectively reviewed. Post-transplant VTE was defined as newly diagnosed venous system thrombus by imaging studies. RESULTS: There were 254 patients. The cohort's median age was 55 years. A total of 61 patients were diagnosed with VTE, including one with right atrial thrombus, 54 with upper extremity DVT in which one patient subsequently developed PE, four with lower extremity DVT, and two with upper and lower extremity DVT. The cumulative incidence of VTE was 42% at 60-days of post heart transplant. Patients with VTE had longer hospital stay (P < .001), higher in-hospital mortality (P = .010), and worse 5-year survival (P = .009). On the multivariable Cox analysis, history of DVT/PE and intubation for more than 3 days were associated with an increased risk of in hospital VTE. CONCLUSION: The incidence of VTE in heart transplant recipients is high. Post-transplant surveillance, and appropriate preventive measures and treatment strategies after diagnosis are warranted.

Changes in waitlist and posttransplant outcomes in patients with adult congenital heart disease after the new heart transplant allocation system.

OBJECTIVE: In 2018, the United Network for Organ Sharing (UNOS) introduced new criteria for heart allocation. This study sought to assess the impact of this change on waitlist and posttransplant outcomes in adult congenital heart disease (ACHD) recipients. METHODS: Between January 2010 and March 2020, we extracted first heart transplant ACHD patients listed from the UNOS database. We compared waitlist and post-transplant outcomes before and after the policy change. RESULTS: A total of 1206 patients were listed, 951 under the old policy and 255 under the new policy. Prior to transplant, recipients under the new policy era were more likely to be treated with extracorporeal membrane oxygenation (P = .018), and have intra-aortic balloon pumps (P < .001), and less likely to have left ventricular assist devices (P = .027).Compared to patients waitlisted in the pre-policy change era, those waitlisted in the post policy change era were more likely to receive transplants (P = .001) with no significant difference in waiting list mortality (P = .267) or delisting (P = .915). There was no difference in 1-year survival post-transplant between the groups (P = .791). CONCLUSION: The new policy altered the heart transplant cohort in the ACHD group, allowing them to receive transplants earlier with no changes in early outcomes after heart transplantation.

A rare childhood case of Behcet's disease and chronic thromboembolic pulmonary hypertension.

BACKGROUND: Pulmonary embolism and chronic thromboembolic pulmonary hypertension (CTEPH) are rare complications of Behcet's disease, especially in pediatric patients. AIMS/METHODS/RESULTS/CONCLUSIONS: This case report highlights a presentation of CTEPH in an adolescent with Behcet's disease. A multidisciplinary approach was required for managing this patient's CTEPH, which successfully reversed the patient's pulmonary hypertension.

Simultaneous heart-kidney transplant compared with heart transplant alone in patients with borderline renal function who are not dialysis dependent.

OBJECTIVE: This study assessed characteristics and outcomes of patients who are not dependent on dialysis receiving simultaneous heart kidney transplantation versus heart transplantation alone (HTA) to identify optimal eGFR threshold where combined transplant strategy may be superior. METHODS: This study retrospectively analyzed 7896 adult patients with estimated glomerular filtration rate (eGFR) <60 mL/minute from the United Network for Organ Sharing database who received HTA or simultaneous heart kidney transplant between 2005 and 2021, excluding those who received pretransplant dialysis. Subjects were further stratified into 3 groups based on chronic kidney disease stage at time of transplant: Stage 3A (eGFR 45-59 mL/minute; n = 5044), Stage 3B (eGFR 30-44 mL/minute; n = 2193), and Stage 4 or 5 (eGFR <30 mL/minute; n = 659). Outcomes of interest were all-cause mortality, cardiac allograft failure, and freedom from chronic dialysis or renal transplant following heart transplant. RESULTS: Simultaneous heart kidney transplant and HTA recipients differed in various baseline characteristics. Simultaneous heart kidney transplant recipients with eGFR <45 mL/minute had greater short- and long-term overall survival and cardiac allograft survival compared with HTA, as well as greater long-term freedom from chronic dialysis or renal transplant. These results were consistent with both propensity matched analyses and multivariable Cox regression analysis of 10 year outcomes. Optimal cutoff value for pretransplant eGFR in predicting elevated risk of renal failure in recipients of heart transplant alone was found to be eGFR ∼45 mL/minute. CONCLUSIONS: Similar to patients with eGFR <30 mL/minute, patients with eGFR 30 to 44 mL/minute who underwent simultaneous heart kidney transplant had superior outcomes compared with HTA, suggesting possible benefit of combined transplant strategy for this subset of heart transplant candidates.

Disparities in the treatment of cardiogenic shock: does sex matter?

OBJECTIVES: The use of extracorporeal life support for cardiogenic shock has significantly increased over the past decade. However, there are insufficient data for the presence of sex-associated outcomes differences. Our study assesses differences between male and female patients placed on venoarterial extracorporeal life support (VA-ECLS) for cardiogenic shock from an international database. METHODS: This is a multicentre, retrospective study on 9888 adult patients on VA-ECLS for cardiogenic shock from the Extracorporeal Life Support Organization registry from 2011 to 2019. The 1:1 nearest neighbour propensity score matching was performed. The primary end point was in-hospital mortality. Secondary end points include bleeding, infection and other complications. RESULTS: There were 6747 (68%) male patients and 3141 (32%) female patients. Male patients were more likely to have history of myocardial infarction, coronary artery disease, diabetes, chronic kidney disease and congestive heart failure. Female patients were more likely to be centrally cannulated. After propensity score matching, there was no difference seen in in-hospital mortality. In regards to complications, female patients were more likely to experience limb ischaemia, whereas males were more likely to receive renal replacement therapy and have longer hospital stays. Multivariable logistic regression confirmed sex was not independently associated with mortality. CONCLUSIONS: There was no difference in-hospital mortality between male and female patients receiving VA-ECLS for cardiogenic shock. Female patients were more likely to have limb ischaemia as a complication. Varying cannulation approaches for female patients should be further investigated.

Acute Kidney Injury After Pulmonary Thromboendarterectomy: Associated Factors and Impact.

BACKGROUND: Acute kidney injury (AKI) is a common complication after pulmonary thromboendarterectomy (PTE) that has been shown to be associated with worse outcomes. Our study assesses factors associated with the development of postoperative AKI after PTE and its impact on clinical outcomes. METHODS: We retrospectively analyzed 247 patients who underwent PTE at our institution between June 2009 and December 2020. Baseline characteristics, risk factors, and outcomes were compared between patients with and without postoperative AKI. The primary endpoint was development of postoperative AKI using the Kidney Disease Improving Global Outcomes definition, and secondary endpoints were length of hospital stay, hospital mortality, and 5-year mortality. RESULTS: The overall incidence of postoperative AKI in our study population was 49%. One hundred twenty-three patients (50.8%) did not develop AKI postoperatively, 87 patients (35.9%) developed stage 1 AKI postoperatively, 21 patients (8.7%) developed stage 2 AKI postoperatively, and 11 (4.5%) developed stage 3 AKI postoperatively. Patients who developed AKI postoperatively had longer hospital stays, higher in-hospital mortality rates, and higher 5-year mortality rates than patients who did not develop postoperative AKI. Higher body mass index, older age, low preoperative hemoglobin, low ejection fraction, and low creatinine were shown to be associated with postoperative AKI development. CONCLUSIONS: Patients who developed AKI after PTE had worse mortality and morbidity. Clinicians should have a lower threshold for suspecting AKI and consider implementing Kidney Disease Improving Global Outcomes-based AKI prevention bundles for patients with factors associated with development of AKI.

Impact of sex, race and socioeconomic status on survival after pulmonary thromboendarterectomy for chronic thromboembolic pulmonary hypertension.

OBJECTIVES: Pulmonary thromboendarterectomy (PTE) is a definitive treatment for chronic thromboembolic pulmonary hypertension. Demographic-based disparities in PTE outcomes have not been well-studied. METHODS: We reviewed all patients who underwent PTE for chronic thromboembolic pulmonary hypertension between 2009 and 2019 at our institution, tracking demographic information including self-identified race, preoperative characteristics and 2-year survival. Socioeconomic status was assessed using the zip code-linked Distressed Communities Index, a validated holistic measure of community well-being. Survival was estimated using Kaplan-Meier method and factors associated with mortality were estimated using Cox regression. RESULTS: Of 235 PTE patients, 101 (42.9%) were white and 87 (37.0%) were black. White patients had a higher median age at surgery (57 vs 51 years, P = 0.035) and a lower degree of economic distress (33.6 vs 61.2 percentile, P < 0.001). Regarding sex, 106 (45.1%) patients were male and 129 (53.6%) were female. Male patients had a higher median age (59 vs 50 years, P = 0.004), greater rates of dyslipidaemia (34% vs 20.2%, P = 0.025), a lower ejection fraction (55% vs 57%, P = 0.046) and longer cross-clamp (77 vs 67.50 min, P = 0.004) and circulatory arrest times (42 vs 37.50 min, P = 0.007). No difference was observed in unadjusted 2-year survival after PTE between patients stratified by race and sex (P = 0.35). After adjustment for clinically relevant variables, neither socioeconomic status, sex nor race were associated with mortality in Cox proportional hazard analysis. CONCLUSIONS: Sex, socioeconomic status and race were not associated with adverse outcomes after PTE in our single-centre experience.

Sex differences in patients with cardiogenic shock requiring extracorporeal membrane oxygenation.

OBJECTIVE: Our study assesses differences between male and female patients placed on venoarterial extracorporeal membrane oxygenation for cardiogenic shock. METHOD: We retrospectively analyzed 574 adult patients placed on venoarterial extracorporeal membrane oxygenation for cardiogenic shock at our institution between January 2007 and December 2018. Baseline characteristics and outcomes were assessed. Propensity score matching was used to compare outcomes. The primary end point was in-hospital mortality. Secondary outcomes include limb ischemia, limb ischemia interventions, distal perfusion cannula placement, stroke, bleeding, and continuous venovenous hemofiltration initiation. RESULTS: There were 394 male patients (69%) and 180 female patients (31%). After adjusting for baseline differences, propensity score matching compared 171 male patients with 171 female patients. No difference was seen between men and women in in-hospital mortality (60.2% vs 56.7%; P = .59), limb ischemia (47.4% vs 45.6%; P = .83), limb ischemia surgery (15.2% vs 12.9%; P = .64), bleeding (49.7% vs 49.1%; P = 1), continuous venovenous hemofiltration initiation (39.2% vs 32.7%; P = .26), and stroke (8.2% vs 9.4%; P = .85). Multivariable logistic regression showed that female patients who died were more likely to have had chronic kidney disease (odds ratio [OR], 2.67; 95% confidence interval [CI], 1.09-6.53; P = .032) than surviving women. Male patients who died were more likely to have had coronary artery disease (OR, 2.25; 95% CI, 1.34-3.78; P = .002) and higher lactate levels (OR, 1.14; 95% CI, 1.08-1.21; P < .001) than surviving men. Women with cardiac transplant primary graft dysfunction were more likely to survive (OR, 0.04; 95% CI, 0.01-0.27; P = .001), whereas men with cardiac transplant primary graft dysfunction were less likely to survive (OR, 0.28; 95% CI, 0.11-0.71; P = .007), than patients with other shock etiologies. CONCLUSIONS: After adjusting for baseline difference, there was no difference in outcomes between male and female patients despite differing risk profiles for in-hospital mortality.

Cardiac Corrected QT Interval Changes Among Patients Treated for COVID-19 Infection During the Early Phase of the Pandemic.

Importance: Critical illness, a marked inflammatory response, and viruses such as SARS-CoV-2 may prolong corrected QT interval (QTc). Objective: To evaluate baseline QTc interval on 12-lead electrocardiograms (ECGs) and ensuing changes among patients with and without COVID-19. Design, Setting, and Participants: This cohort study included 3050 patients aged 18 years and older who underwent SARS-CoV-2 testing and had ECGs at Columbia University Irving Medical Center from March 1 through May 1, 2020. Patients were analyzed by treatment group over 5 days, as follows: hydroxychloroquine with azithromycin, hydroxychloroquine alone, azithromycin alone, and neither hydroxychloroquine nor azithromycin. ECGs were manually analyzed by electrophysiologists masked to COVID-19 status. Multivariable modeling evaluated clinical associations with QTc prolongation from baseline. Exposures: COVID-19, hydroxychloroquine, azithromycin. Main Outcomes and Measures: Mean QTc prolongation, percentage of patients with QTc of 500 milliseconds or greater. Results: A total of 965 patients had more than 2 ECGs and were included in the study, with 561 (58.1%) men, 198 (26.2%) Black patients, and 191 (19.8%) aged 80 years and older. There were 733 patients (76.0%) with COVID-19 and 232 patients (24.0%) without COVID-19. COVID-19 infection was associated with significant mean QTc prolongation from baseline by both 5-day and 2-day multivariable models (5-day, patients with COVID-19: 20.81 [95% CI, 15.29 to 26.33] milliseconds; P < .001; patients without COVID-19: -2.01 [95% CI, -17.31 to 21.32] milliseconds; P = .93; 2-day, patients with COVID-19: 17.40 [95% CI, 12.65 to 22.16] milliseconds; P < .001; patients without COVID-19: 0.11 [95% CI, -12.60 to 12.81] milliseconds; P = .99). COVID-19 infection was independently associated with a modeled mean 27.32 (95% CI, 4.63-43.21) millisecond increase in QTc at 5 days compared with COVID-19-negative status (mean QTc, with COVID-19: 450.45 [95% CI, 441.6 to 459.3] milliseconds; without COVID-19: 423.13 [95% CI, 403.25 to 443.01] milliseconds; P = .01). More patients with COVID-19 not receiving hydroxychloroquine and azithromycin had QTc of 500 milliseconds or greater compared with patients without COVID-19 (34 of 136 [25.0%] vs 17 of 158 [10.8%], P = .002). Multivariable analysis revealed that age 80 years and older compared with those younger than 50 years (mean difference in QTc, 11.91 [SE, 4.69; 95% CI, 2.73 to 21.09]; P = .01), severe chronic kidney disease compared with no chronic kidney disease (mean difference in QTc, 12.20 [SE, 5.26; 95% CI, 1.89 to 22.51; P = .02]), elevated high-sensitivity troponin levels (mean difference in QTc, 5.05 [SE, 1.19; 95% CI, 2.72 to 7.38]; P < .001), and elevated lactate dehydrogenase levels (mean difference in QTc, 5.31 [SE, 2.68; 95% CI, 0.06 to 10.57]; P = .04) were associated with QTc prolongation. Torsades de pointes occurred in 1 patient (0.1%) with COVID-19. Conclusions and Relevance: In this cohort study, COVID-19 infection was independently associated with significant mean QTc prolongation at days 5 and 2 of hospitalization compared with day 0. More patients with COVID-19 had QTc of 500 milliseconds or greater compared with patients without COVID-19.