Role of Radiology in Assessment of Postoperative Complications of Heart Transplantation.

Heart transplantation is a pivotal treatment of end-stage heart failure, and recent advancements have extended median posttransplant life expectancy. However, despite the progress in surgical techniques and medical treatment, heart transplant patients still face complications such as rejection, infections, and drug toxicity. CT is a reliable tool for detecting most of these complications, whereas MR imaging is particularly adept at identifying pericardial pathologies and signs of rejection. Awareness of these nuances by radiologists, cardiologists, and surgeons is desired to optimize care, reduce morbidities, and enhance survival.

One Year Outcomes Following Transplantation with COVID-19-Positive Donor Hearts: A National Database Cohort Study.

The current understanding of the safety of heart transplantation from COVID-19+ donors is uncertain. Preliminary studies suggest that heart transplants from these donors may be feasible. We analyzed 1-year outcomes in COVID-19+ donor heart recipients using 1:3 propensity matching. The OPTN database was queried for adult heart transplant recipients between 1 January 2020 and 30 September 2022. COVID-19+ donors were defined as those who tested positive on NATs or antigen tests within 21 days prior to procurement. Multiorgan transplants, retransplants, donors without COVID-19 testing, and recipients allocated under the old heart allocation system were excluded. A total of 7211 heart transplant recipients met the inclusion criteria, including 316 COVID-19+ donor heart recipients. Further, 290 COVID-19+ donor heart recipients were matched to 870 COVID-19- donor heart recipients. Survival was similar between the groups at 30 days (p = 0.46), 6 months (p = 0.17), and 1 year (p = 0.07). Recipients from COVID-19+ donors in the matched cohort were less likely to experience postoperative acute rejection prior to discharge (p = 0.01). National COVID-19+ donor heart usage varied by region: region 11 transplanted the most COVID-19+ hearts (15.8%), and region 6 transplanted the fewest (3.2%). Our findings indicate that COVID-19+ heart transplantation can be performed with safe early outcomes. Further analyses are needed to determine if long-term outcomes are equivalent between groups.

Venovenous Extracorporeal Membrane Oxygenation Candidacy Decision-Making: Lessons and Hypotheses From a Single-Center Observational Analysis.

BACKGROUND: Use of venovenous extracorporeal membrane oxygenation (ECMO) is increasing, but candidacy selection processes are variable and subject to bias. RESEARCH QUESTION: What are the reasons behind venovenous ECMO candidacy decisions, and are decisions made consistently across patients? STUDY DESIGN AND METHODS: Prospective observational study of all patients, admitted or outside hospital referrals, considered for venovenous ECMO at a tertiary referral center. Relevant clinical data and reasons for candidacy determination were cross-referenced with other noncandidates and candidates and were assessed qualitatively. RESULTS: Eighty-one consultations resulted in 44 noncandidates (54%), 29 candidates (36%; nine of whom subsequently underwent cannulation), and eight deferred decisions (10%). Fifteen unique contraindications were identified, variably present across all patients. Five contraindications were invoked as the sole reason to deny ECMO to a patient. In patients with three or more contraindications, additional contraindications were cited even if the severity was relatively minor. All but four contraindications invoked to deny ECMO to a patient were nonprohibitive for at least one other candidate. Contraindications documented in noncandidates were present but not mentioned in 21 other noncandidates (47%). Twenty-six candidates (90%) had at least one contraindication that was prohibitive in a noncandidate, including a contraindication that was the sole reason to deny ECMO. Contraindications were proposed as informing three prognostic domains, through which patterns of inconsistency could be understood better: (1) irreversible underlying pulmonary process, (2) unsurvivable critical illness, and (3) clinical condition too compromised for meaningful recovery. INTERPRETATION: ECMO candidacy decisions are inconsistent. We identified four patterns of inconsistency in our center and propose a three-domain model for understanding and categorizing contraindications, yielding five lessons that may improve candidacy decision processes until further research can guide practice more definitively.

Acute rejection in donation after circulatory death (DCD) heart transplants.

BACKGROUND: Donation after circulatory death (DCD) heart transplantation has promising early survival, but the effects on rejection remain unclear. METHODS: The United Network for Organ Sharing database was queried for adult heart transplants from December 1, 2019, to December 31, 2021. Multiorgan transplants and loss to follow-up were excluded. The primary outcome was acute rejection, comparing DCD and donation after brain death (DBD) transplants. RESULTS: A total of 292 DCD and 5,582 DBD transplants met study criteria. Most DCD transplants were transplanted at status 3-4 (61.0%) compared to 58.6% of DBD recipients at status 1-2. DCD recipients were less likely to be hospitalized at transplant (26.7% vs 58.3%, p < 0.001) and to require intra-aortic balloon pumping (IABP; 9.6% vs 28.9%, p < 0.001), extracorporeal membrane oxygenation (ECMO; 0.3% vs 5.9%, p < 0.001) or temporary left ventricular assist device (LVAD; 1.0% vs 2.7%, p < 0.001). DCD recipients were more likely to have acute rejection prior to discharge (23.3% vs 18.4%, p = 0.044) and to be hospitalized for rejection (23.4% vs 11.4%, p = 0.003) at a median follow-up of 15 months; the latter remained significant after propensity matching. On multivariable logistic regression, DCD donation was an independent predictor of acute rejection (odds ratio [OR] 1.47, 95% confidence interval [CI] 1.00-2.15, p = 0.048) and hospitalization for rejection (OR 2.03, 95% CI 1.06-3.70, p = 0.026). On center-specific subgroup analysis, DCD recipients continued to have higher rates of hospitalization for rejection (23.4% vs 13.8%, p = 0.043). CONCLUSIONS: DCD recipients are more likely to experience acute rejection. Early survival is similar between DCD and DBD recipients, but long-term implications of increased early rejection in DCD recipients require further investigation.

Does Failure to Rescue Drive Race/Ethnicity-based Disparities in Survival After Heart Transplantation?

OBJECTIVE: The objective was to assess whether race/ethnicity is an independent predictor of failure to rescue (FTR) after orthotopic heart transplantation (OHT). SUMMARY BACKGROUND DATA: Outcomes following OHT vary by patient level factors; for example, non-White patients have worse outcomes than White patients after OHT. Failure to rescue is an important factor associated with cardiac surgery outcomes, but its relationship to demographic factors is unknown. METHODS: Using the United Network for Organ Sharing database, we included all adult patients who underwent primary isolated OHT between 1/1/2006 snd 6/30/2021. FTR was defined as the inability to prevent mortality after at least one of the UNOS-designated postoperative complications. Donor, recipient, and transplant characteristics, including complications and FTR, were compared across race/ethnicity. Logistic regression models were created to identify factors associated with complications and FTR. Kaplan Meier and adjusted Cox proportional hazards models evaluated the association between race/ethnicity and posttransplant survival. RESULTS: There were 33,244 adult, isolated heart transplant recipients included: the distribution of race/ethnicity was 66% (n=21,937) White, 21.2% (7,062) Black, 8.3% (2,768) Hispanic, and 3.3% (1,096) Asian. The frequency of complications and FTR differed significantly by race/ethnicity. After adjustment, Hispanic recipients were more likely to experience FTR than White recipients (OR 1.327, 95% CI[1.075-1.639], P =0.02). Black recipients had lower 5-year survival compared with other races/ethnicities (HR 1.276, 95% CI[1.207-1.348], P <0.0001). CONCLUSIONS: In the US, Black recipients have an increased risk of mortality after OHT compared with White recipients, without associated differences in FTR. In contrast, Hispanic recipients have an increased likelihood of FTR, but no significant mortality difference compared with White recipients. These findings highlight the need for tailored approaches to addressing race/ethnicity-based health inequities in the practice of heart transplantation.

The effect of warm ischemia and donor ejection fraction on 30-day mortality after donation after circulatory death heart transplantation: A national database analysis.

Donation after circulatory death (DCD) donor hearts recovered using the direct procurement and perfusion method experience variable durations of warm ischemia at the time of procurement (WIP). We used the Organ Procurement and Transplantation Network database to assess the effect of WIP on 30-day mortality after DCD heart transplantation. The analysis evaluated outcomes in 237 recipients of DCD heart transplantation, demonstrating an optimal WIP cut point of <36 minutes. Multivariable logistic regression modeling identified donor left ventricular ejection fraction (LVEF) <60% as an independent predictor of 30-day mortality. The area under the receiver operating characteristic curve for predicting 30-day mortality based on WIP ≥36 minutes and donor LVEF <60% was 0.90. Based on these findings, we do not recommend proceeding with DCD heart transplantation for patients with WIP ≥36 minutes, particularly in donors with LVEF <60%.

Is Transplantation With Coronavirus Disease 2019-Positive Donor Lungs Safe? A US Nationwide Analysis.

BACKGROUND: Since the beginning of the pandemic, coronavirus disease 2019 (COVID-19) has caused debilitating lung failure in many patients. Practitioners have understandably been hesitant to use lungs from donors with COVID-19 for transplantation. This study aimed to analyze the characteristics and short-term outcomes of lung transplantation from donors with recent positive COVID-19 testing results. METHODS: Lung transplantations performed between January 2020 and June 2022 were queried from the United Network for Organ Sharing database. Pediatric, multiorgan, and repeat lung transplantations were excluded. Propensity scoring matched recipients of lungs from donors with recent positive COVID-19 testing results to recipients of lungs from donors with negative COVID-19 testing results, and comparisons of 30-day mortality, 3-month mortality, and perioperative outcomes were performed. RESULTS: A total of 5270 patients underwent lung transplantation during the study dates, including 51 patients who received lungs from donors with recent positive COVID-19 testing results. Forty-five recipients of lungs from donors with recent positive COVID-19 testing results were matched with 135 recipients of lungs from donors with negative COVID-19 testing results. After matching, there was no difference in 30-day (log-rank P = .42) and 3-month (log-rank P = .42) mortality. The incidence of other perioperative complications was similar between the groups. CONCLUSIONS: The 30-day and 3-month survival outcomes were similar between recipients of lungs from donors with recent positive COVID-19 testing results and recipients of lungs from donors with negative COVID-19 testing results. This finding suggests that highly selected COVID-19-positive donors without evidence of active infection may be safely considered for lung transplantation. Further studies should explore long-term outcomes to provide reassurance about the safety of this practice.

Racial Disparities in Coronavirus Disease 2019 Mortality Are Present in Heart Transplant Recipients.

BACKGROUND: Studies have demonstrated the devastating effects of coronavirus disease 2019 (COVID-19) on vulnerable populations. Although they receive close follow-up, heart transplant recipients represent a particularly vulnerable population, given long-term immunosuppression and comorbid conditions. We sought to investigate the association between race/ethnicity and the probability of death due to COVID-19 in adult heart transplant recipients in the United States. METHODS: Adult isolated heart transplant recipients were identified using the Organ Procurement and Transplantation Network database. Recipients who were described as deceased or lost to follow-up before January 2020 were excluded. Recipients were stratified into 4 cohorts by race/ethnicity. The primary outcome of interest was death due to COVID-19. RESULTS: A total of 22 157 adult recipients were identified. During the course of follow-up, 153 recipients had COVID-19 reported as the primary cause of death. COVID-19 mortality was significantly different between race/ethnicity cohorts (Black, n = 34 [0.79%]; Hispanic, n = 23 [1.33%]; White, n = 92 [0.60%]; other, n = 4 [0.44%]; P = .007). COVID-19 was listed as a contributing cause of mortality in 0.12% of Black, 0.23% of Hispanic, 0.04% of White, and 0.33% of other recipients (P = .002). No significant difference in non-COVID mortality or all-cause mortality was observed. After multivariable adjustment, Black (hazard ratio, 2.78 [1.40-5.52]; P = .003) and Hispanic (hazard ratio, 3.92 [1.88-8.16]; P < .001) recipients were at higher risk of death due to COVID-19 compared with White recipients. CONCLUSIONS: Compared with White recipients, Black and Hispanic recipients experienced higher rates of COVID-19 mortality after transplantation. These findings suggest that racial/ethnic disparities of COVID-19 mortality in the general population persist in adult heart transplant recipients.

Hemodynamic and Clinical Performance of Hearts Donated After Circulatory Death.

BACKGROUND: Donor organ demand continues to outpace supply in heart transplantation. Utilization of donation after circulatory death (DCD) hearts could significantly increase heart donor availability for patients with advanced heart failure. OBJECTIVES: The purpose of this study was to describe hemodynamic and clinical profiles of DCD hearts in comparison to standard of care (SOC) hearts donated after brain death (DBD). METHODS: This single-center retrospective cohort study of consecutive heart transplant recipients analyzed right heart catheterization measurements, inotrope scores, echocardiograms, and clinical outcomes between DCD and DBD heart recipients. RESULTS: Between April 2016 and February 2022, 47 DCD and 166 SOC hearts were transplanted. Median time from DCD consent to transplant was significantly shorter compared with SOC waiting list time (17 days [6-28 days] vs 70 days [23-240 days]; P < 0.001). Right heart function was significantly impaired in DCD recipients compared with SOC recipients 1 week post-transplant (higher median right atrial pressure (10 mm Hg [8-13 mm Hg] vs 7 mm Hg [5-11 mm Hg]; P < 0.001), higher right atrial pressure to pulmonary capillary wedge pressure ratio (0.64 [0.54-0.82] vs 0.57 [0.43-0.73]; P = 0.016), and lower pulmonary arterial pulsatility index (1.66 [1.27-2.50] vs 2.52 [1.63-3.82]; P < 0.001), but was similar between groups by 3 weeks post-transplant. DCD and SOC recipient mortality was similar at 30 days (DCD 0 vs SOC 2%; P = 0.29) and 1 year post-transplant (DCD 3% vs SOC 8%; P = 0.16). CONCLUSIONS: DCD heart utilization is associated with transient post-transplant right heart dysfunction and short-term clinical outcomes otherwise similar to transplantation using DBD hearts.

Lung Retransplantation.

Lung retransplantation remains the standard treatment of irreversible lung allograft failure. The most common indications for lung retransplantation are acute graft failure, chronic lung allograft dysfunction, and postoperative airway complications. Careful patient selection with regards to indications, anatomy, extrapulmonary organ dysfunction (specifically renal dysfunction), and immunologic consideration are of utmost importance. The conduct of the lung retransplantation operation is arduous with special considerations given to operative approach, type of surgery (single vs bilateral), use of extracorporeal circulatory support, and hematological management. Outcomes have improved significantly for most patients, nearing short and midterm outcomes of primary lung recipients in select cases.

Effect of Impella 5.5 on Preexisting Functional Mitral Regurgitation in Patients with Heart Failure-Related Cardiogenic Shock.

Background: Heart failure-related cardiogenic shock (HF-CS) is increasingly common. Moderate/severe functional mitral regurgitation (FMR) is commonly seen in patients presenting with decompensated heart failure and is associated with worse outcomes. Percutaneous mechanical circulatory support devices are increasingly used to provide hemodynamic support for ongoing CS. There is no description of the impact of Impella device on hemodynamic response when used in combination with preexisting FMR. Methods: Retrospective review of patients aged ≥18 years, who underwent Impella 5.5 implant for HF-CS, and who had a transthoracic echocardiogram performed pre- and post-Impella. Results: Of 24 patients, 33% had moderate-to-severe/severe FMR, 38% had mild-moderate/moderate FMR, and 29% had trace/mild FMR on pre-Impella transthoracic echocardiogram. Additional right ventricular assist device was simultaneously inserted in 3 patients, of whom 1 had severe, 1 had moderate, and another had mild FMR pre-Impella. Despite maximally tolerated Impella unloading, 6 patients (25%) had persistent moderate-severe/severe FMR, and 9 (37.5%) patients had persistent moderate FMR. Overall, however, there was a decrease in central venous pressure, pulmonary artery diastolic pressure, serum lactate, and vasoactive-inotrope score at 24 â€‹hours post-Impella, and survival was high at 83%. Conclusions: In a retrospective cohort of patients admitted with HF-CS who underwent Impella 5.5 implant for hemodynamic support, Impella did not seem to acutely ameliorate FMR severity. Despite this, there was a significant improvement in hemodynamic response at 24 â€‹hours post-Impella. In carefully selected patients, especially those with isolated left ventricular failure, Impella 5.5 may provide adequate hemodynamic support even in the presence of higher severity FMR.

Veno-Venous Extracorporeal Rewarming Using Dual-Lumen Cannula in Accidental Hypothermia.

Accidental hypothermia with a core temperature below 28°C is associated with an increased risk of hemodynamic instability. It is difficult to predict which patients will survive with a favorable neurologic outcome; therefore, decision-making regarding extracorporeal support is not straightforward. We report a case of rewarming using veno-venous dual-lumen cannula as an alternative to veno-arterial support with full recovery and normal neurologic examination. In centers where extracorporeal membrane oxygenation is available, rewarming using veno-venous dual-lumen extracorporeal support may be a useful strategy to mitigate the risks associated with veno-arterial extracorporeal support.

Fulminant myocarditis in a patient with coronavirus disease 2019 and rapid myocardial recovery following treatment.

Coronavirus disease 2019 (COVID-19) is a global pandemic increasingly encountered in the clinical setting. It typically manifests as a respiratory illness, although cardiac involvement is common and portends a worse prognosis. We present the case of a 56-year-old male admitted with COVID-19 fulminant myocarditis and cardiogenic shock. We discuss important aspects of the multidisciplinary and interventional care involved in treating cardiogenic shock as well as the likely mechanisms of, and potential treatment for, COVID-19 myocarditis. The various pathways of myocardial injury, including direct viral damage, macrophage activation, and lymphocytic infiltration, are outlined in detail in addition to associated pathology such as cytokine release syndrome. COVID-19 is a complex and multisystem disease process; in addition to supportive care, specific consideration should be given to the underlying mechanism of injury for each patient.

Predictors of Left Ventricular Dysfunction After Surgery for Degenerative Mitral Regurgitation.

BACKGROUND: This study was performed to determine whether strain can supplement the ability of left ventricular (LV) ejection fraction (LVEF) to predict postoperative ventricular dysfunction in patients undergoing mitral valve surgery for degenerative mitral regurgitation (DMR). METHODS: From 2004 to 2017, 520 patients with an LVEF of 60% or more underwent mitral valve surgery (98% repair) for DMR. All patients had preoperative, predischarge, and follow-up (mean, 5.0 ± 3.6 years) echocardiograms. Speckle tracking was performed in 119 of 520 patients (22.9%) to determine LV strain, right ventricular free-wall strain, and left atrial longitudinal strain. Multivariate logistic and Cox regression models were used in this subgroup to evaluate associations with early postoperative LV dysfunction and medium-term overall survival, respectively. RESULTS: Median preoperative LVEF of the entire cohort was 65%. Based on predischarge echocardiogram, 449 patients (86.3%) maintained postoperative LVEF of 50% or greater. Seventy-one patients (13.7%) had a predischarge LVEF of less than 50%, 49 (9.4%) had a predischarge LVEF of 40% to 49%, and 22 (4.2% overall) had a predischarge LVEF of less than 40%. Abnormal preoperative LV, right ventricular, and left atrial strain measurements were significantly associated with the development of postoperative LV dysfunction, but preoperative hemodynamic and non-strain echo parameters did not vary enough in absolute values to be clinically useful as predictors of postoperative LV dysfunction. CONCLUSIONS: Preoperative strain measurements in DMR patients were significantly associated with superior capabilities of detecting underlying LV dysfunction despite preserved preoperative LVEF. Strain analysis may serve as another marker for optimal timing of surgical intervention in DMR patients.

Bridge to Transplantation With Long-Term Mechanical Assist Devices in Adults With Transposition of the Great Arteries.

Prior to the widespread adoption of the arterial switch operation, patients with transposition of the great arteries (TGA) commonly underwent atrial switch operation (Mustard or Senning). It is not uncommon for these patients to progress to end stage heart failure and increasingly ventricular assist devices (VADs) are used to support these patients as a bridge to transplantation, though there is limited experience with this worldwide. A retrospective review of our institution's VAD database was undertaken and revealed seven adult patients with a history of TGA and subsequent systemic ventricular failure were implanted with a VAD: four of whom received the VAD as a bridge to transplantation (BTT) at the time of implantation, two who were initially designated as destination therapy secondary to severe pulmonary hypertension, and one who was designated as destination therapy secondary to a high risk of life-threatening non-compliance. Seven patient cases who received a VAD for severe systemic ventricular failure were included in this study. The mean age of the patients was 40 years and the majority of patients were male (6/7, 85%). Five of the patients (71.4%) had previously undergone an atrial switch operation and all of these were Mustard procedures. Two of the seven patients (28.5%) had congenitally corrected transposition of the great arteries (CC-TGA). Two of the seven patients (28.5%) had supra-systemic pulmonary pressures before VAD implantation and were designated as destination therapy (DT). One of these patients was later designated as BTT as an improvement in his pulmonary vascular resistance was observed, and subsequently underwent heart transplantation. Because of anatomic considerations, four of the patients (57%) underwent redo-sternotomy with outflow cannula anastomosis to the ascending aorta, one patient underwent VAD implantation via a left subcostal incision with anastomosis of the outflow graft to the descending thoracic aorta, and two patients (28.5%) underwent VAD implantation via a left thoracotomy and anastomosis of the outflow cannula to the descending thoracic aorta. Six of the seven patients had a HeartWare HVAD VAD implanted; one received a Thoratec Heartmate II VAD. Two patients underwent VAD explant and orthotopic heart transplant, 222 days and 444 days after VAD implant, respectively. One patient died on postoperative day 17 after complications from recurrent VAD thrombosis despite multiple pump exchanges. Four patients remain on VAD support, three of these patients are awaiting transplantation at last follow-up (mean days on support, 513 days). Bridge to transplantation with a durable VAD is technically feasible and relatively safe in patients with TGA. Multiple redo-sternotomies can be avoided with a left posterior thoracotomy approach and outflow graft anastomosis to the descending thoracic aorta after careful anatomic considerations.

Evidence-Based Bundled Quality Improvement Intervention for Reducing Surgical Site Infection in Lower Extremity Vascular Bypass Procedures.

BACKGROUND: Surgical site infection (SSI) poses a significant burden to patients and healthcare resources. Vascular Quality Initiative (VQI) data identify a higher rate of SSIs for lower extremity bypass than other vascular procedures. Bundled interventions have successfully reduced SSIs in other surgical procedures. STUDY DESIGN: We evaluated our institution-specific VQI data for modifiable risk factors associated with index hospitalization SSI from January 2012 through October 2015. We implemented an evidence-based lower extremity bypass operation SSI reduction bundle (ie perioperative chlorhexidine showers and transverse groin incisions) and prospectively enrolled all patients who had lower extremity bypass procedures, with a target adherence rate of 50% per bundle component. Bundle adherence and SSI events were measured from March 2016 through August 2017. We carried out a pre-post evaluation of bundle effectiveness in reducing index hospitalization SSI. RESULTS: In the pre-intervention period, 43 of 234 (18%) patients had SSI events. The only risk factors associated with SSI (ie female sex, diabetes, overweight BMI) were not readily modifiable. In an 18-month period after introduction of our intervention, adherence rates to preoperative chlorhexidine showers, a transverse incision, and a postoperative chlorhexidine shower were 71% (52 of 73), 48% (24 of 50), and 88% (64 of 73), respectively. Compliance with all applicable bundle components was 36% (26 of 73). The SSI rate post-intervention decreased from 18% to 4% (3 of 73). Intention-to-treat multivariable analysis showed a 97% SSI risk reduction with the bundle (p = 0.002). As-treated analysis identified 85% (p = 0.02) and 62% (p = 0.047) SSI risk reductions from the preoperative and postoperative chlorhexidine showers, respectively. CONCLUSIONS: In this evaluation study of the effectiveness of a quality improvement intervention, SSIs were markedly decreased after implementation of our evidence-based bundle for lower extremity vascular bypass procedures.

Valve-in-valve-prosthesis embolization and aortic dissection: single procedure, double complication.

Transcatheter aortic valve implantation (TAVI) is a recognized treatment method for high-risk patients with aortic stenosis. TAVI is also recommended for structural valve degeneration of a biological valve prosthesis. TAVI-specific complications, such as prosthesis embolization and aortic dissection, are uncommon but potential concerns. A 73-year-old woman presented with structural valve degeneration 14 years after aortic root replacement with a bioprosthetic valved conduit. The patient underwent TAVI valve-in-valve under monitored anaesthesia care. Intraoperatively, the self-expandable prosthesis was difficult to deploy within the valved conduit and ultimately migrated distally. During the technically difficult passage of the prosthesis delivery system through the tortuous aorta, the patient started reporting symptoms suggestive of aortic dissection. An emergency computed tomography scan confirmed type B dissection. Thoracic endovascular aortic repair followed by deployment of a balloon-expandable prosthesis below the self-expandable implant was performed. Careful prosthesis selection in valve-in-valve patients after aortic root replacement is crucial for procedural success.