Predictors and Impact of Prolonged Vasoplegia After Continuous-Flow Left Ventricular Assist Device Implantation.

Background: Vasoplegia after cardiac surgery is associated with adverse outcomes. However, the clinical effects of vasoplegia and the significance of its duration after continuous-flow left ventricular assist device (CF-LVAD) implantation are less known. Objectives: This study aimed to identify predictors of and outcomes from transient vs prolonged vasoplegia after CF-LVAD implantation. Methods: The study was a retrospective review of consecutive patients who underwent CF-LVAD implantation between January 1, 2005, and December 31, 2017. Vasoplegia was defined as the presence of all of the following: mean arterial pressure ≤65 mm Hg, vasopressor (epinephrine, norepinephrine, vasopressin, or dopamine) use for >6 hours within the first 24 hours postoperatively, cardiac index ≥2.2 L/min/m2 and systemic vascular resistance <800 dyne/s/cm5, and vasodilatory shock not attributable to other causes. Prolonged vasoplegia was defined as that lasting 12 to 24 hours; transient vasoplegia was that lasting 6 to <12 hours. Patient characteristics, outcomes, and risk factors were analyzed. Results: Of the 600 patients who underwent CF-LVAD implantation during the study period, 182 (30.3%) developed vasoplegia. Mean patient age was similar between the vasoplegia and no-vasoplegia groups. Prolonged vasoplegia (n = 78; 13.0%), compared with transient vasoplegia (n = 104; 17.3%), was associated with greater 30-day mortality (16.7% vs 5.8%; P = 0.02). Risk factors for prolonged vasoplegia included preoperative dialysis and elevated body mass index. Conclusions: Compared with vasoplegia overall, prolonged vasoplegia was associated with worse survival after CF-LVAD implantation. Treatment to avoid or minimize progression to prolonged vasoplegia may be warranted.

Incidence, Risk Score Performance, and In-Hospital Outcomes of Postoperative Atrial Fibrillation After Cardiac Surgery.

BACKGROUND: Postoperative atrial fibrillation (POAF) frequently complicates cardiac surgery. Predicting POAF can guide interventions to prevent its onset. This study assessed the incidence, risk factors, and related adverse outcomes of POAF after cardiac surgery. METHODS: A cohort of 1,606 patients undergoing cardiac surgery at a tertiary referral center was analyzed. Postoperative AF was defined based on the Society of Thoracic Surgeons' criteria: AF/atrial flutter after operating room exit that either lasted longer than 1 hour or required medical or procedural intervention. Risk factors for POAF were evaluated, and the performance of established risk scores (POAF, HATCH, COM-AF, CHA2DS2-VASc, and Society of Thoracic Surgeons risk scores) in predicting POAF was assessed using discrimination (area under the receiver operator characteristics curve) analysis. The association of POAF with secondary outcomes, including length of hospital stay, ventilator time, and discharge to rehabilitation facilities, was evaluated using adjusted linear and logistic regression models. RESULTS: The incidence of POAF was 32.2% (n = 517). Patients who developed POAF were older, had traditional cardiovascular risk factors and higher Society of Thoracic Surgeons risk scores, and often underwent valve surgery. The POAF risk score demonstrated the highest area under the receiver operator characteristics curve (0.65), but risk scores generally underperformed. Postoperative AF was associated with extended hospital stays, longer ventilator use, and higher likelihood of discharge to rehabilitation facilities (odds ratio, 2.30; 95% CI, 1.73-3.08). CONCLUSION: This study observed a high incidence of POAF following cardiac surgery and its association with increased morbidity and resource utilization. Accurate POAF prediction remains elusive, emphasizing the need for better risk-prediction methods and tailored interventions to diminish the effect of POAF on patient outcomes.

Clinical Predictors and Outcomes After Left Ventricular Assist Device Implantation and Tracheostomy.

BACKGROUND: Postoperative respiratory failure is a major complication that affects up to 10% of patients who undergo cardiac surgery and has a high in-hospital mortality rate. Few studies have investigated whether patients who require tracheostomy for postoperative respiratory failure after continuous-flow left ventricular assist device (CF-LVAD) implantation have worse survival outcomes than patients who do not. OBJECTIVE: To identify risk factors for respiratory failure necessitating tracheostomy in CF-LVAD recipients and to compare survival outcomes between those who did and did not require tracheostomy. METHODS: Consecutive patients who underwent primary CF-LVAD placement at a single institution between August 1, 2002, and December 31, 2019, were retrospectively reviewed. Propensity score matching accounted for baseline differences between the tracheostomy and nontracheostomy groups. Multivariate logistic regression was used to identify tracheostomy risk factors and 90-day survival; Kaplan-Meier analysis was used to assess midterm survival. RESULTS: During the study period, 664 patients received a CF-LVAD; 106 (16.0%) underwent tracheostomy for respiratory failure. Propensity score matching produced 103 matched tracheostomy-nontracheostomy pairs. Patients who underwent tracheostomy were older (mean [SD] age, 57.9 [12.3] vs 54.6 [13.9] years; P = .02) and more likely to need preoperative mechanical circulatory support (61.3% vs 47.8%; P = .01) and preoperative intubation (27.4% vs 8.8%; P < .001); serum creatinine was higher in the tracheostomy group (mean [SD], 1.7 [1.0] vs 1.4 [0.6] mg/dL; P < .001), correlating with tracheostomy need (odds ratio, 1.76; 95% CI, 1.21-2.56; P = .003). Both before and after propensity matching, 30-day, 60-day, 90-day, and 1-year survival were worse in patients who underwent tracheostomy. Median follow-up was 0.8 years (range, 0.0-11.2 years). Three-year Kaplan-Meier survival was significantly worse for the tracheostomy group before (22.0% vs 61.0%; P < .001) and after (22.4% vs 48.3%; P < .001) matching. CONCLUSION: Given the substantially increased probability of death in patients who develop respiratory failure and need tracheostomy, those at high risk for respiratory failure should be carefully considered for CF-LVAD implantation. Comprehensive management to decrease respiratory failure before and after surgery is critical.

Twenty-year survival following lung transplantation.

Background: Lung transplantation median survival has seen improvements due to recognition of short-term survival factors but continues to trail behind other solid organs due to limited understanding of long-term survivorship. Given the creation of the United Network for Organ Sharing (UNOS) database in 1986, it was difficult to accrue data on long-term survivors until recently. This study characterizes factors impacting lung transplant survival beyond 20 years, conditional to 1-year survival. Methods: Lung transplant recipients listed in UNOS from 1987 to 2002 who survived to 1 post-transplant year were reviewed. Kaplan-Meier and adjusted Cox regression analyses were performed at 20 and 10 years to identify risk factors associated with long-term outcomes independent of their short-term effects. Results: A total of 6,172 recipients were analyzed, including 472 (7.6%) recipients who lived 20+ years. Factors associated with increased likelihood of 20-year survival were female-to-female gender match, recipient age 25-44, waitlist time >1 year, human leukocyte antigen (HLA) mismatch level 3, and donor cause of death: head trauma. Factors associated with decreased 20-year survival included recipient age ≥55, chronic obstructive pulmonary disease/emphysema (COPD/E) diagnosis, donor smoking history >20 pack-years, unilateral transplant, blood groups O&AB, recipient glomerular filtration rate (GFR) <10 mL/min, and donor GFR 20-29 mL/min. Conclusions: This is the first study identifying factors associated with multiple-decade survival following lung transplant in the United States. Despite its challenges, long-term survival is possible and more likely in younger females in good waitlist condition without COPD/E who receive a bilateral allograft from a non-smoking, gender-matched donor of minimal HLA mismatch. Further analysis of the molecular and immunologic implications of these conditions are warranted.

COMPETENCE Trial: The EVAHEART 2 continuous flow left ventricular assist device.

BACKGROUND: Continuous flow left ventricular assist devices have improved outcomes in patients with end-stage heart failure that require mechanical circulatory support. Current devices have an adverse event profile that has hindered widespread application. The EVAHEART®2 left ventricular assist device (EVA2) has design features such as large blood gaps, lower pump speeds and an inflow cannula that does not protrude into the left ventricle that may mitigate the adverse events currently seen with other continuous flow devices. METHODS: A prospective, multi-center randomized non-inferiority study, COMPETENCE Trial, is underway to assess non-inferiority of the EVA2 to the HeartMate 3 LVAS when used for the treatment of refractory advanced heart failure. The primary end-point is a composite of the individual primary outcomes: Survival to cardiac transplant or device explant for recovery; Free from disabling stroke; Free from severe Right Heart Failure after implantation of original device. Randomization is in a 2:1 (EVA2:HM3) ratio. RESULTS: The first patient was enrolled into the COMPETENCE Trial in December of 2020, and 25 subjects (16 EVA2 and 9 HM3) are currently enrolled. Enrollment of a safety cohort is projected to be completed by third quarter of 2022 at which time an interim analysis will be performed. Short-term cohort (92 EVA2 subjects) and long-term cohort is expected to be completed by the end of 2023 and 2024, respectively. CONCLUSIONS: The design features of the EVA2 such as a novel inflow cannula and large blood gaps may improve clinical outcomes but require further study. The ongoing COMPETENCE trial is designed to determine if the EVA2 is non-inferior to the HM3.

Preoperative hyponatremia and survival after left ventricular assist device implantation.

BACKGROUND: Hyponatremia is associated with adverse outcomes in heart failure and after cardiac surgery. We hypothesized that hyponatremia is associated with poorer short-term and longer term survival in patients after continuous-flow left ventricular assist device (CF-LVAD) placement. METHODS: We reviewed a single-center database of patients who received a CF-LVAD during 2012-2017. Sodium (Na) values obtained within 14 days before CF-LVAD insertion were averaged; patients (n = 332) were divided into hyponatremia (mean Na <135 mEq/L; n = 160; 48.2%) and normonatremia groups (mean Na 135-145 mEq/L; n = 172; 51.8%). Patients requiring preoperative dialysis or pump exchange were excluded. We compared outcomes between preoperative hyponatremia and normonatremia groups. RESULTS: The two groups' baseline characteristics were similar, although hyponatremia patients more often had preoperative mechanical circulatory support (44.4% vs. 31.4%, p = 0.002). Although hyponatremic and normonatremic patients did not differ in 30-day mortality (7.5% vs. 6.5%, p = 0.7), preoperative hyponatremia was associated with greater 5-year mortality (61% vs. 44%, p = 0.03). On binary logistic regression analysis, the strongest independent predictors of late mortality were hyponatremia (odds ratio [OR] 1.88, 95% CI [1.07-3.31], p = 0.02), older age (OR 1.03, 95% CI [1.01-1.05], p = 0.01), and elevated mean right atrial pressure/pulmonary capillary wedge pressure ratio (OR 4.69, 95% CI [1.76-12.47], p = 0.002). CONCLUSIONS: Hyponatremia was not associated with greater early mortality but was associated with poorer late survival. The optimal timing of LVAD implantation in relation to hyponatremia, and whether correcting hyponatremia perioperatively improves long-term survival, should be investigated.

Predictors of renal replacement therapy in patients with continuous flow left ventricular assist devices.

Renal replacement therapy (RRT) after continuous flow left ventricular assist device (CF-LVAD) implantation significantly affects patients' quality of life and survival. To identify preoperative prognostic markers in patients requiring RRT after CF-LVAD implantation, we retrospectively reviewed data from patients who underwent implantation of a CF-LVAD at our institution during 2012-2017. Patients who required preoperative RRT were excluded. Preoperative and operative characteristics, as well as survival and adverse events, were compared between 74 (22.2%) patients requiring any duration of postoperative RRT and 259 (77.8%) not requiring RRT. Patients requiring RRT experienced more postoperative complications than patients who did not, including respiratory failure necessitating tracheostomy (35.7% vs 2.5%, p < 0.001), reoperation for bleeding (34.3% vs 11.7%, p < 0.001), and right heart failure necessitating perioperative mechanical circulatory support (32.4% vs 6.9%, p < 0.001). Patients requiring postoperative RRT also had poorer survival at 30 days (74.7% vs 98.8%), 6 months (48.2% vs 95.1%), and 12 months (45.3% vs 90.2%) (p < 0.001). Significant predictors of RRT after CF-LVAD implantation included urine proteinuria (odds ratio [OR] 3.6, 95% confidence interval [CI] [1.7-7.6], p = 0.001), estimated glomerular filtration rate < 45 mL/min/1.73 m2 (OR 3.4, 95% CI [1.5-17.8], p = 0.004), and mean right atrial pressure to pulmonary capillary wedge pressure ratio ≥ 0.54 (OR 2.6, 95% CI [1.3-5.], p = 0.01). Of the 74 RRT patients, 11 (14.9%) recovered renal function before discharge, 36 (48.6%) still required RRT after discharge, and 27 (36.5%) died before discharge. We conclude that preoperative renal and right ventricular dysfunction significantly predict postoperative renal failure and mortality after CF-LVAD implantation.

Simple Felt-Plug Closure Technique for Minimally Invasive Removal of a Centrifugal-Flow Left Ventricular Assist Device.

As the indications for implanting left ventricular assist devices have expanded, some patients are qualifying for device removal after myocardial recovery. Whereas explantation has been described for previous generations of devices, no standard procedures have been developed. Removal of centrifugal-flow devices has created the need for a plug to seal the apical ventriculotomy after pump removal. However, no commercially available products are available in the United States. We used a novel technique to fashion a plug from Teflon felt and a Dacron graft to enable minimally invasive explantation of a current-generation centrifugal-flow device in a 33-year-old woman.

Review of donor and recipient surgical procedures in lung transplantation.

Lung transplant remains the only durable treatment of end stage lung disease. Efficient surgical technique and preservation strategy are of critical importance in avoiding ischemia reperfusion injury and primary graft dysfunction (PGD), both associated with poorer outcomes. We present our surgical and preservation strategy for both donor and recipient procedures, including endobronchial and intracorporeal lung assessment, mediastinal dissection, lung preservation, donor pneumonectomy, back bench preparation, recipient approach, pneumonectomy, along with the bronchial, pulmonary artery, and pulmonary venous anastomoses.

Outcomes of Lung Transplantation for Cystic Fibrosis in the Setting of Extensively Drug-Resistant Organisms.

INTRODUCTION: Since the largest study on extensively drug-resistant organisms and lung transplantation in patients with cystic fibrosis, there have been innovations and advancements in the treatment of Pseudomonas aeruginosa. RESEARCH QUESTION: What differences exist for patients with cystic fibrosis with a history of extensively drug-resistant infections who undergo lung transplantation despite treatment advances with antimicrobial therapy? STUDY DESIGN: Two-center, retrospective, cohort study conducted in 44 patients with cystic fibrosis chronically infected with extensively drug-resistant organisms who received a lung transplant from January 2008 through August 2016. Patients in the resistant cohort were chronically infected with pan-resistant P aeruginosa, polymyxin-sensitive only, or sensitive to 2 antibiotic classes (polymyxin plus one other); remaining patients with more susceptible P aeruginosa or no P aeruginosa remained in the control cohort. The primary outcome is a composite of patient survival, retransplantation, chronic lung allograft dysfunction, and acute rejection 12 months posttransplant. Categorical variables were analyzed using χ2 testing. The independent samples t test was utilized for continuous variables. RESULTS: There was no difference in the primary outcome (40% vs 37%, P = .831). Differences between patient survival (84% vs 95%, P = .487), the incidence of acute rejection (20% vs 33%, P = .323), and the incidence of chronic lung allograft rejection (12% vs 5%, P = .441) were not different between groups. DISCUSSION: Recipients chronically infected with an extensively resistant P aeruginosa had similar outcomes compared to those infected with more sensitive organisms.

Increased blood transfusion and its impact in patients having tracheostomy while on extracorporeal membrane oxygenation.

INTRODUCTION: Tracheostomy has been utilized in combination with venovenous extracorporeal membrane oxygenation (VV-ECMO) to enable early spontaneous breathing and minimize sedation requirements. Tracheostomy has been previously reported to be safe in patients supported on VV-ECMO; however, the impact of tracheostomy on blood loss in VV-ECMO patients is unknown. METHODS: We analyzed VV-ECMO patients with and without tracheostomy over a 5-year period. In order to avoid other potential sources of blood loss not related to tracheostomy or ECMO-related blood loss, patients who underwent a recent surgery prior to ECMO or during ECMO (other than tracheostomy) were excluded. RESULTS: Sixty-three patients meeting the inclusion criteria were identified (tracheostomy n=30, non-tracheostomy n=33). Tracheostomy patients were found to require more daily transfusions of red blood cells (RBC) (0.47 [0.20-1.0] vs. 0.23 [0.06-0.40] units/day, p=0.02) and total blood products (0.60 [0.32-1.0] vs. 0.31 [0.10-0.50] units/day, p=0.01). CONCLUSIONS: These results suggest that tracheostomy while on VV-ECMO predisposes patients to increased transfusion burden. Based on previous research, this increased transfusion burden could potentially be linked to increased complications and mortality.

Impact of donor lung pathogenic bacteria on patient outcomes in the immediate post-transplant period.

BACKGROUND: Patient outcomes post-lung transplant remain inferior to other types of solid organ transplantation. We investigated whether the presence of potentially pathogenic bacteria (PPB) in donor lung bronchial cultures was associated with adverse outcomes postoperatively. METHODS: All patients who underwent lung transplantation between August 2015 and April 2017 at the University of Kentucky Medical Center were retrospectively reviewed. Retransplants, patients with bronchiectasis (including cystic fibrosis), and individuals who received organs from donation after cardiac death (DCD) donors were excluded. The remaining subjects were separated into two groups: individuals whose donor bronchial cultures grew PPB, and those whose cultures either returned negative for PPB or were sterile. 30-day mortality rates as well as the incidence of grade 3 primary graft dysfunction (PGD) and acute kidney injury (AKI) at both 24 and 72 hours post-transplant were calculated. The duration of mechanical ventilation postoperatively was also recorded. RESULTS: Thirty two subjects comprised the study population. 20 patients (63%) had growth of PPB on donor cultures, while 12 (37%) did not. Patients with PPB had a significantly greater number of days on the ventilator postoperatively compared to those with no PPB (mean = 11.3 and median = 5.0 vs mean = 5.8 and median = 3.0, respectively, P = 0.0232). Subsequent regression analysis revealed this association to not be influenced by recipient lung allocation score (LAS), donor age, donor smoking history, recipient mean pulmonary artery pressure (mPAP) value, and/or use of cardiopulmonary bypass at the time of transplantation. Neither 30-day survival nor incidence of Grade 3 PGD and AKI at 24 or 72 hours post-transplant differed between the two groups (P > 0.05). CONCLUSION: The recovery of PPB in donor lung cultures was associated with a longer duration of mechanical ventilation postoperatively in lung transplant recipients.

Clinical and morphologic features of acute, subacute and chronic cor pulmonale (pulmonary heart disease).

Described are certain clinical and morphologic features of one patient with acute, another with subacute, and one with chronic cor pulmonale. All 3 had evidence of severe pulmonary hypertension. The patient with acute cor pulmonale 4 days after coronary bypass for unstable angina pectoris suddenly developed severe breathlessness with cyanosis and had fatal cardiac arrest and necropsy disclosed massive pulmonary embolism. The patient with subacute cor pulmonale had severe right-sided heart failure for 5 weeks and necropsy disclosed microscopic-sized neoplastic pulmonary emboli from a gastric carcinoma without parenchymal pulmonary metastases. The patient with chronic cor pulmonale had evidence of right-sided heart failure for years, the result of primary or idiopathic pulmonary hypertension almost certainly present from birth because the pattern of elastic fibers in the pulmonary trunk was that seen in newborns where the pressure in the pulmonary trunk and ascending aorta are similar. The patient with chronic cor pulmonale had plexiform pulmonary lesions indicative of irreversible pulmonary hypertension. Neither the acute nor the subacute patient had chronic pulmonary vascular changes. All 3 patients had dilated right ventricular cavities and non-dilated left ventricular cavities and only the patient with chronic cor pulmonale had right ventricular hypertrophy.

Expanding the donor pool: donation after cardiac death.

Lung transplantation (LTx) is the definitive treatment of patients with end-stage lung disease. Availability of donor lungs remains the primary limitation and leads to substantial wait-list mortality. Efforts to expand the donor pool have included a resurgence of interest in the use of donation after cardiac death (DCD) lungs. Unique in its physiology, lung viability seems more tolerant to the variable durations of ischemia that occur in DCD donors. Initial experience with DCD LTx is promising and, in combination with ex vivo lung perfusion systems, seems a valuable opportunity to expand the lung donor pool.

Too high for transplantation? Single-center analysis of the lung allocation score.

BACKGROUND: Recent studies using United Network for Organ Sharing data suggest that lung transplantation in patients with high lung allocation scores (LAS) may lead to organ and resource wastage. Therefore, to determine whether a LAS cutoff value should be considered, we evaluated the relation of LAS to waitlist and posttransplant mortality in our center to determine if it could identify patients for whom listing for transplantation may be futile. METHODS: From May 1, 2005 to July 1, 2010, 537 adults were listed and 426 underwent primary lung transplantation at our institution. Endpoints were mortality before and after lung transplantation. The relationships of LAS at listing to waitlist mortality and of pretransplant LAS to posttransplant mortality were both analyzed by multiphase hazard function methodology. RESULTS: Higher LAS was strongly associated with waitlist mortality (p<0.0001), with the highest quartile (LAS ranging from 47 to 95) experiencing 75% mortality within a year of listing. Although early (p=0.05), but not late (p=0.4), posttransplant survival was associated with higher LAS at transplantation, once other clinical characteristics predictive of early mortality were accounted for, neither waitlist nor pretransplant LAS was independently related to posttransplant mortality (p=0.12). CONCLUSIONS: Higher LAS strongly predicts higher mortality on the lung transplantation waitlist, underscoring the value of LAS in prioritizing patients with the highest scores for transplantation. Early posttransplant mortality is modestly higher with higher pretransplant LAS, but the data of our center do not suggest a value above which transplantation should be denied as futile. This suggests that donor organs and resources are not being wasted.

Outcomes of axillary artery side graft cannulation for extracorporeal membrane oxygenation.

OBJECTIVE: To determine the safety, efficacy, and frequency of side graft axillary artery cannulation for extracorporeal membrane oxygenation support and compare it with other cannulation techniques. METHODS: From January 2001 to October 2011, 308 adult patients were supported with extracorporeal membrane oxygenation at a single center. In 81 patients (26.3%), the extracorporeal membrane oxygenation circuit was composed of an arterial inflow by a side graft sewn to the axillary artery. Of the 308 patients, 166 (53.9%) underwent femoral arterial cannulation and 61 (19.8%) underwent ascending aortic cannulation The pertinent variables and postprocedural events were retrospectively analyzed in this cohort of patients. RESULTS: The most common complication in the axillary artery group was hyperperfusion syndrome of the ipsilateral upper extremity (n = 20, 24.7%), followed by bleeding from the arterial outflow graft (n = 14, 17.3%). Lower extremity ischemia and fasciotomy were more frequent after femoral arterial cannulation (n = 27, 16%, and n = 18, 10.8%, respectively). The predictors for a poor in-hospital outcome for the entire group of patients were age and postoperative cerebral vascular accident. The cannulation method was not a predictor of in-hospital outcomes. CONCLUSIONS: Extracorporeal membrane oxygenation support with side graft axillary artery technique was more frequently associated with hyperperfusion syndrome than other cannulation sites. Lower extremity ischemia and compartment syndrome was more common after femoral arterial cannulation.

Combined heart and liver transplantation: the Cleveland Clinic experience.

BACKGROUND: Combined heart-liver transplantation (CHLT) has been utilized as a life-saving procedure in those with end-stage cardiac and hepatic pathology. Techniques and outcomes of this procedure are varied. We sought to review the Cleveland Clinic experience with CHLT. METHODS: This study is a retrospective chart review of patients who received simultaneous heart and liver transplantation between January 2006 and December 2012. RESULTS: Five patients received CHLT. The mean age was 49 (± 20) years. All cardiac pathology was nonischemic cardiomyopathy, with a mean ejection fraction of 0.36 (± 0.13). Three of the 5 were on preoperative inotropic support, 1 of which required placement of a total artificial heart for support pretransplant. Liver pathology was amyloid in 1 patient and hepatitis C in the remaining 4. Mean Model for End-Stage Liver Disease score was 17 (± 5), and mean Childs-Pugh score was 8 (± 1). Survival, now at a mean of 38 (± 20) months remains 100%, with no cardiac or hepatic graft dysfunction or episodes of rejection. One hospital readmission was required for gastroenteritis at 15 months posttransplant. CONCLUSIONS: These results suggest that excellent outcomes can be achieved in this extremely sick cohort of patients, and add to the growing literature of perioperative management of CHLT recipients.