Pulmonary hypertension as a risk factor of mortality after lung transplantation

Lung Transplantation in Pulmonary Arterial Hypertension: The Portuguese Experience

BACKGROUND

In patients with pulmonary arterial hypertension (PAH), refractory to medical therapy, lung transplantation emerges as an option. This study describes the outcomes of 8 PAH patients who underwent lung transplantation.

METHODS

A retrospective, single-center study was conducted among patients with PAH who underwent lung transplantation in our center.

RESULTS

Patients had a median age of 46 years, with female sex predominance (75%). Causes of HAP were pulmonary veno-occlusive disease (n = 5, 62.5%), idiopathic PAH (n = 2, 25%), and heritable PAH (n = 1, 12.5%). Pre-transplant hemodynamics revealed a median mean pulmonary artery pressure of 58.5 mm Hg (48-86). All patients received bilateral lung transplants with extracorporeal membrane oxygenation support, displaying immediate post-transplant hemodynamic improvement. Primary graft dysfunction grade 3 (PGD 3) was observed in 75% of patients. Five patients (62.5%) died, with a 72.9% survival at 12 months and 29.2% at 24 months post-transplantation.

CONCLUSION

Our study reveals the complexity and challenges of lung transplants in patients with PAH. Despite notable immediate hemodynamic improvements, high rates of PGD 3 and the survival rate remain a concern. Further research to define optimal peri and post-transplant management to improve survival is required.

Lung Transplantation in Patients With Systemic Scleroderma-Description of the First Consecutive Cases in Poland: Case Series Report and a Short Literature Review

Pulmonary complications of systemic scleroderma (SSc), such as interstitial lung disease and pulmonary hypertension (PH), are responsible for up to 60% of deaths among patients. For many years, most centers considered SSc a contraindication to lung transplantation (LTx); however, recent publications show that appropriately selected SSc candidates for LTx give results comparable to patients with idiopathic PH or idiopathic pulmonary fibrosis. This paper presents the cases of a 60-year-old male patient (patient 1) and a 42-year-old female patient (patient 2) diagnosed with SSc in 2019 and 2013, respectively. In both patients, interstitial-fibrotic changes in the lungs leading to respiratory failure were confirmed by high-resolution computed tomography as well as pulmonary hypertension (WHO group 3), which was also diagnosed during right heart catheterization. In both cases, despite pharmacotherapy, pulmonary fibrosis progressed, leading to severe respiratory failure. The patients were referred for LTx qualification. LTx was possible to consider in patients due to the lack of significant changes in other internal organs. Double LTx was successfully performed in both patients (patient 1-July 19, 2022; patient 2-September 14, 2022). They were discharged from the hospital in good condition on the 22nd and 20th postoperative day, respectively. LTx is a last-chance therapy that saves lives among patients with extreme respiratory failure in the course of SSc. It prolongs and improves the quality of life. The selection of appropriate patients is key to the success of the procedure.

Thoracic Ultrasound in Lung Transplantation—Insights in the Field

The use of thoracic ultrasound (TUS) is a novel and dynamic diagnostic and monitoring modality that has shown remarkable advances within the last decade, with several published papers investigating its role within the field of lung transplantation. The aim of this current opinion review is to review the existing literature on the role of TUS in all stages of LTx, from in-donor lung evaluation to graft assessment on ex vivo lung perfusion and in the short- and long-term follow-up after LTx.

Association of Pulmonary Hypertension with Survival and Neurologic Outcomes in Adults with In-Hospital Cardiac Arrest

BACKGROUND

Pulmonary hypertension (PH) has been associated with poor survival in multiple cardiopulmonary conditions, however its association with outcomes in cardiac arrest remains unknown. We aimed to evaluate the association of PH with survival and neurologic outcomes in adults with in-hospital cardiac arrest (IHCA).

METHODS

The study population included adults with IHCA undergoing resuscitation at an academic tertiary medical center from 2011-2019. Patients were classified based upon the presence versus absence of PH, defined as a pulmonary artery systolic pressure > 35mmHg on pre-arrest echocardiogram. Survival to discharge and favorable neurological outcome (defined as a Glasgow Outcome Score of 4-5) served as the primary and secondary outcomes of interest respectively.

RESULTS

Of the 371 patients studied, 203 (54.7%) had PH while 168 (45.3%) did not. Patients with PH had higher Charlson Comorbidity Score with higher rates of multiple baseline comorbidities. They also had worse multi-chamber enlargement, left ventricular diastolic dysfunction, right ventricular systolic dysfunction, and valvular heart disease compared to non-PH patients. Rates of survival to discharge (11.5% vs 10.9%, p=0.881) and favorable neurologic outcome (8.0% vs 6.2%, p=0.550) were similar in PH and non-PH patients respectively. In multivariable analysis, PH was not associated with survival to discharge (OR 1.23, 95%CI 0.57-2.65) or favorable neurologic outcome (OR 1.69, 95%CI 0.64 - 4.45).

CONCLUSIONS

In this contemporary registry of adults with IHCA, while PH was associated with a higher risk patient profile, it was not associated with survival or neurologic outcomes in this population.

Accuracy of echocardiography and chest tomography for pulmonary hypertension screening in patients awaiting lung transplantation

OBJECTIVE

To examine the accuracy of a pulmonary hypertension screening strategy based on a combination of echocardiographic data and tomographic measurements (pulmonary artery diameter and pulmonary artery diameter to ascending aorta diameter ratio) in patients with chronic lung disease referred for lung transplantation.

METHODS

A retrospective observational study with patients with pulmonary emphysema or fibrosis referred for transplantation between 2012 and 2016. Pulmonary hypertension was defined as mean pulmonary artery pressure ≥25mmHg, or between 21 and 24mmHg, with pulmonary vascular resistance >3 Wood units on right heart catheterization. Tomographic measurements were made by two independent radiologists.

RESULTS

This sample comprised 13 patients with emphysema and 19 patients with pulmonary fibrosis. Of these, 18 had pulmonary hypertension. The level of agreement in tomographic measurements made by radiologists was high (intraclass correlation coefficients 0.936 and 0.940, for pulmonary artery diameter and pulmonary artery diameter to ascending aorta diameter ratio, respectively). Areas under the ROC curves constructed for pulmonary artery diameter, pulmonary artery diameter to ascending aorta diameter ratio, and pulmonary artery systolic pressure as predictors of pulmonary hypertension were 0.540, 0.629 and 0.783, respectively. The sensitivity, specificity and negative predictive value of pulmonary artery systolic pressure ≥40mmHg were 67%, 79% and 65%, respectively. The combined criterion (pulmonary artery diameter to ascending aorta diameter ratio >1 and/or pulmonary artery systolic pressure ≥40mmHg) achieved sensitivity of 72%, specificity of 79%, and a negative predictive value of 69%.

CONCLUSION

Measurements of pulmonary artery and ascending aorta diameter were highly reproducible. The association of pulmonary artery and aortic diameter >1 and/or pulmonary artery systolic pressure ≥40mmHg improved the sensitivity and the negative predictive value for pulmonary hypertension screening. This strategy demands prospective validation to assess safety and cost-effectiveness.

Lung Disease-Related Pulmonary Hypertension

Patients with advanced lung disease can develop pulmonary hypertension and succumb to right ventricular failure/cor pulmonale. Patients with pulmonary hypertension owing to chronic lung disease, or World Health Organization group 3 pulmonary hypertension, are more limited and carry a high risk of mortality. Adjunctive therapies remain the cornerstones of treatment. Recent evidence suggests that inhaled pulmonary vasodilator therapy can be helpful in patients with pulmonary hypertension owing to interstitial lung disease. Lung transplantation may be the only life-saving option in select patients, whereas palliative care and hospice should be sought for those who are not candidates as the disease progresses.

Meticulous closure of collateral vessels in the perihilar mediastinal pleura to control intraoperative bleeding during lung transplantation for pulmonary hypertension

Background

Massive blood transfusion compensating hemorrhage during lung transplantation (LT) results in primary graft dysfunction (PGD) and worse outcomes after LT. Collateral vessels in the perihilar mediastinal pleura could be the source of hemorrhage during LT in patients with pulmonary hypertension (PH). The purpose of this study was to examine the effect of closure with hemoclips of the vessels in the perihilar mediastinal pleura on the risk of intraoperative hemorrhage and outcomes after LT in patients with PH.

Methods

We retrospectively reviewed 80 patients who underwent LT, including 13 patients with primary PH, 29 patients with secondary PH, and 38 patients with non-PH.

Results

The median number of hemoclips was significantly higher in the primary PH group than in the non-PH group (P=0.0045) or secondary PH group (P=0.0060). The intraoperative blood loss, transfusion volume, maximum PGD grade, and the 30-day and 90-day mortality rates in the primary PH group were equivalent to those in the other two groups.

Conclusions

Meticulous closure of collateral vessels in the perihilar mediastinal pleura during LT in patients with primary PH allowed intraoperative hemorrhage to be controlled and might be associated with acceptable mortality rate in these patients similar to that of LT in patients with other diseases.

The prognostic value of peak arterial lactate levels within 72 h of lung transplantation in identifying patient outcome

Background

Lactic acidosis is often seen in lung transplantation (LTx). Postoperative lactate is frequently associated with poor outcome in postoperative and critically ill patients. Our aim was to evaluate the predictive value of postoperative peak lactate levels within 72 h of LTx for 30-day and late mortality.

Methods

We evaluated patients who underwent LTx from January 2015 to September 2017. All admitted patients were classified according to the peak lactate level (PL) within 72 h of surgery: PL <5 mmol/L (Group 1); PL =5–10 mmol/L (Group 2), and PL >10 mmol/L (Group 3). We performed logistic regression analysis and used Cox regression models to identify the peak lactate level as a predictive factor for 30-day and late mortality, respectively.

Results

Of 255 eligible patients, mean age 55.61±12.16, mean lactate 4.99±2.93 and 80% male, and 40% had hyperlactatemia (PL >5 mmol/L) after LTx. The 30-day mortality rate was 17.9%, 28.9% and 68.8% in the three groups, respectively (P<0.05). Multivariate regression analyses revealed postoperative PL as a notable predictor of 30-day mortality [odds ratio =2.62 (1.42–4.84), P=0.002] as well as for late mortality [hazard ratio =2.70 (1.13–6.42), P=0.025].

Conclusions

The postoperative peak lactate level within 72 h of surgery was an independent predictor for 30-day and late mortality in LTx patients.

Extracellular Superoxide Dismutase Regulates Early Vascular Hyaluronan Remodeling in Hypoxic Pulmonary Hypertension

Chronic hypoxia leads to pathologic remodeling of the pulmonary vasculature and pulmonary hypertension (PH). The antioxidant enzyme extracellular superoxide dismutase (SOD3) protects against hypoxia-induced PH. Hyaluronan (HA), a ubiquitous glycosaminoglycan of the lung extracellular matrix, is rapidly recycled at sites of vessel injury and repair. We investigated the hypothesis that SOD3 preserves HA homeostasis by inhibiting oxidative and enzymatic hyaluronidase-mediated HA breakdown. In SOD3-deficient mice, hypoxia increased lung hyaluronidase expression and activity, hyaluronan fragmentation, and effacement of HA from the vessel wall of small pulmonary arteries. Hyaluronan fragmentation corresponded to hypoxic induction of the cell surface hyaluronidase-2 (Hyal2), which was localized in the vascular media. Human pulmonary artery smooth muscle cells (HPASMCs) demonstrated hypoxic induction of Hyal2 and SOD-suppressible hyaluronidase activity, congruent to our observations in vivo. Fragmentation of homeostatic high molecular weight HA promoted HPASMC proliferation in vitro, whereas pharmacologic inhibition of hyaluronidase activity prevented hypoxia- and oxidant-induced proliferation. Hypoxia initiates SOD3-dependent alterations in the structure and regulation of hyaluronan in the pulmonary vascular extracellular matrix. These changes occurred soon after hypoxia exposure, prior to appearance of PH, and may contribute to the early pathogenesis of this disease.

Outcome of lung transplantation in non-idiopathic pulmonary fibrosis interstitial lung disease

Lung transplantation remains the only curative treatment option for selected patients with end-stage interstitial lung disease (ILD). Candidate selection is impeded by patient heterogeneity, particularly in the subgroup of non-idiopathic pulmonary fibrosis (non-IPF) interstitial lung diseases. We performed a descriptive analysis of all non-IPF ILD patients who underwent lung transplantation in our center between July 1991 and November 2016 (n = 129) and searched for pre-transplant variables correlating with graft loss and chronic lung allograft dysfunction (CLAD). Our study cohort was characterized by a significantly affected medical condition, an extensive pre-transplant corticosteroid use (73.8%), and a high prevalence of pulmonary hypertension (55.7%). Earlier year of transplantation (P = .004), higher bilirubin level (P < .0001), older recipient age (P = .04), and smaller recipient height (P = .02) were found to be associated with earlier graft loss in multivariate analysis. Moreover, pre-transplant corticosteroid treatment tended to be related to earlier graft loss (P = .06), while pulmonary hypertension did not significantly correlate. None of the pre-transplant variables were shown to be associated with CLAD development. Ongoing research is required to further explore this diverse patient population and the pre-transplant variables determining their post-transplant outcome.

Retrospective observational analysis of hospital discharge database to characterize primary pulmonary hypertension and its outcomes in Spain from 2004 to 2015

To examine trends in the incidence, characteristics and outcomes, and to identify factors associated with in-hospital mortality (IHM) of patients hospitalized for primary pulmonary hypertension (PPH) in Spain (2004-2015).We included all patients hospitalized with PPH and included in the Spanish National Hospital Discharge Database.We analyzed 46,883 discharges of patients (7.14% with PPH as their primary diagnosis). Incidence rates decreased from 6.15 cases per 100,000 inhabitants in 2004-06 to 3.40 in 2013-15 (P < .001). Mean age rose from 66.43 ± 21.28 to 69.73 ± 21.12 years (P < .001) and the proportion of females increased over the study period (58.44% vs 60.71%; P < .001). Comorbidity using the Charlson Comorbidity Index (CCI) also increased with 16.07% having CCI ≥3 in 2004-06 vs 21.795 in 2013-15. Median length of hospital stay (LOHS) was 1 day longer in period 2004-06, than in 2013-15 (9 vs 8 days; P < .001). The proportion of patients who were considered a readmission and the mean costs increased from 15.7% and 3712.46&OV0556; in the first period to 17.14% and 4040.28&OV0556; in 2013-15 (P < .001). IHM increased from 8.2% in 2004-06 to 9.93% in 2013-15 (P < .001). The predictors' of IHM among PPH patients included comorbidity and use of mechanical ventilation. Primary diagnosis of PPH did not predict higher IHM (OR 1.07; 95%CI 09-1.26).Our data indicates that the incidence of hospitalizations decreased in Spain between 2004 and 2015. Parallel, LOHS also decreased during this period. By contrast, comorbidity increased over time in PPH patients, as well as readmission rates, costs and IHM.

Blood Products Transfusion and Mid-Term Outcomes of Lung Transplanted Patients Under Extracorporeal Membrane Oxygenation Support

INTRODUCTION

Extracorporeal membrane oxygenation (ECMO) is considered a reliable technique in lung transplantation requiring cardiorespiratory support. However, the impact of this technology on blood product transfusion rate and outcomes compared to off-pump lung transplantation has been rarely investigated.

METHODS

Between January 2012 and June 2015, 52 elective adult lung transplants were performed at our institution. Of these, 15 recipients required intraoperative venoarterial extracorporeal support and 37 did not. We compared blood product consumption and other outcome variables between the 2 groups.

RESULTS

We found comparable in-hospital (86.7% vs 97.3%, P = .14) and 6-month (86.7% vs 91.9%, P = .56) survival between patients with and without extracorporeal support, respectively. Survival at 30 days was lower in the ECMO group (86.7% vs 100%, P = .02). Although patients who underwent ECMO received more intraoperative transfusions, postoperative transfusion rate was similar between the 2 groups. The ECMO group experienced longer mechanical ventilation (median 3 vs 2 days, P = .02) and intensive care unit stay (median 7 vs 5 days, P = .02), besides more cardiogenic shock and deep vein thrombosis. However, we observed no difference in other major and minor in-hospital complications and 6-month complications.

CONCLUSIONS

In our experience, despite the higher need for intraoperative transfusions, lung transplantation performed with ECMO support is comparable to the off-pump procedure as to short-term survival and outcomes.

Prognostic value of pre-transplant mean pulmonary arterial pressure in lung transplant recipients: a single-institution experience

Background

Currently, lung transplantation (LTX) is considered to be a curative treatment option in patients with end-stage lung disease. Although pulmonary hypertension (PH), confirmed by cardiac catheterization, is a prognostic factor in patients undergoing LTX, the prognostic value of PH in Asian lung transplant recipients remains uncertain. In this study, we aimed to determine whether PH before LTX may serve as a prognostic factor for survival in Asian patients.

Methods

The medical records of 50 patients [male, 27; female, 23; mean age, 51.0 (41.0-60.0) years], who received preoperative right heart catheterization (RHC) and echocardiography before single or double LTX at Severance Hospital between January 2010 and December 2014, were reviewed. The relationship between 1-year survival after LTX and PH [mean pulmonary arterial pressure (mPAP) ≥25 mmHg at rest] was evaluated.

Results

The mean right ventricular systolic pressure and mPAP were 48.5 (22.8) and 30.0 (24.0-40.0) mmHg. Of the 50 patients, 17 (34.0%) died within a year after LTX. The 1-year survival rate among patients with mPAP ≥25 mmHg (58.8%) was lower than the survival rate among patients with mPAP <25 mmHg (87.5%). Pre-transplantation mPAP of ≥25 mmHg was associated with post-transplantation survival [hazard ratio (HR), 4.832; 95% confidence interval (CI), 1.080-21.608, P=0.039]. The presence of preoperative PH was also associated with an increased risk of postoperative complications.

Conclusions

Confirmation of PH via preoperative cardiac catheterization was associated with the prognosis of the patient after LTX. Clinicians should consider the necessity for early transplantation surgery before the mPAP reaches ≥25 mmHg.

Quantitative Evidence for Revising the Definition of Primary Graft Dysfunction after Lung Transplant

RATIONALE

Primary graft dysfunction (PGD) is a form of acute lung injury that occurs after lung transplantation. The definition of PGD was standardized in 2005. Since that time, clinical practice has evolved, and this definition is increasingly used as a primary endpoint for clinical trials; therefore, validation is warranted.

OBJECTIVES

We sought to determine whether refinements to the 2005 consensus definition could further improve construct validity.

METHODS

Data from the Lung Transplant Outcomes Group multicenter cohort were used to compare variations on the PGD definition, including alternate oxygenation thresholds, inclusion of additional severity groups, and effects of procedure type and mechanical ventilation. Convergent and divergent validity were compared for mortality prediction and concurrent lung injury biomarker discrimination.

MEASUREMENTS AND MAIN RESULTS

A total of 1,179 subjects from 10 centers were enrolled from 2007 to 2012. Median length of follow-up was 4 years (interquartile range = 2.4-5.9). No mortality differences were noted between no PGD (grade 0) and mild PGD (grade 1). Significantly better mortality discrimination was evident for all definitions using later time points (48, 72, or 48-72 hours; P < 0.001). Biomarker divergent discrimination was superior when collapsing grades 0 and 1. Additional severity grades, use of mechanical ventilation, and transplant procedure type had minimal or no effect on mortality or biomarker discrimination.

CONCLUSIONS

The PGD consensus definition can be simplified by combining lower PGD grades. Construct validity of grading was present regardless of transplant procedure type or use of mechanical ventilation. Additional severity categories had minimal impact on mortality or biomarker discrimination.

Noteworthy Literature Published in 2016 for Thoracic Organ Transplantation Anesthesiologists

This article is first in the series to review the published literature on perioperative issues in patients undergoing thoracic solid organ transplantations. We present recent literature from 2016 on preoperative considerations, organ preservation, intraoperative anesthesia management, surgical techniques, postoperative complications, and the impact of perioperative management on short- and long-term outcomes that are pertinent to thoracic transplantation anesthesiologists.

Pulmonary Hypertensive Crisis on Induction of Anesthesia

Anesthesia for lung transplantation remains one of the highest risk surgeries in the domain of the cardiothoracic anesthesiologist. End-stage lung disease, pulmonary hypertension, and right heart dysfunction as well as other comorbid disease factors predispose the patient to cardiovascular, respiratory and metabolic dysfunction during general anesthesia. Perhaps the highest risk phase of surgery in the patient with severe pulmonary hypertension is during the induction of anesthesia when the removal of intrinsic sympathetic tone and onset of positive pressure ventilation can decompensate a severely compromised cardiovascular system. Severe hypotension, cardiac arrest, and death have been reported previously. Here we present 2 high-risk patients for lung transplantation, their anesthetic induction course, and outcomes. We offer suggestions for the safe management of anesthetic induction to mitigate against hemodynamic and respiratory complications.