Coronary revascularization in lung transplant recipients with concomitant coronary artery disease

The role of coronary artery disease in lung transplantation: a propensity-matched analysis

BACKGROUND AND AIMS

Candidate selection for lung transplantation (LuTx) is pivotal to ensure individual patient benefit as well as optimal donor organ allocation. The impact of coronary artery disease (CAD) on post-transplant outcomes remains controversial. We provide comprehensive data on the relevance of CAD for short- and long-term outcomes following LuTx and identify risk factors for mortality.

METHODS

We retrospectively analyzed all adult patients (≥ 18 years) undergoing primary and isolated LuTx between January 2000 and August 2021 at the LMU University Hospital transplant center. Using 1:1 propensity score matching, 98 corresponding pairs of LuTx patients with and without relevant CAD were identified.

RESULTS

Among 1,003 patients having undergone LuTx, 104 (10.4%) had relevant CAD at baseline. There were no significant differences in in-hospital mortality (8.2% vs. 8.2%, p > 0.999) as well as overall survival (HR 0.90, 95%CI [0.61, 1.32], p = 0.800) between matched CAD and non-CAD patients. Similarly, cardiovascular events such as myocardial infarction (7.1% CAD vs. 2.0% non-CAD, p = 0.170), revascularization by percutaneous coronary intervention (5.1% vs. 1.0%, p = 0.212), and stroke (2.0% vs. 6.1%, p = 0.279), did not differ statistically between both matched groups. 7.1% in the CAD group and 2.0% in the non-CAD group (p = 0.078) died from cardiovascular causes. Cox regression analysis identified age at transplantation (HR 1.02, 95%CI [1.01, 1.04], p < 0.001), elevated bilirubin (HR 1.33, 95%CI [1.15, 1.54], p < 0.001), obstructive lung disease (HR 1.43, 95%CI [1.01, 2.02], p = 0.041), decreased forced vital capacity (HR 0.99, 95%CI [0.99, 1.00], p = 0.042), necessity of reoperation (HR 3.51, 95%CI [2.97, 4.14], p < 0.001) and early transplantation time (HR 0.97, 95%CI [0.95, 0.99], p = 0.001) as risk factors for all-cause mortality, but not relevant CAD (HR 0.96, 95%CI [0.71, 1.29], p = 0.788). Double lung transplant was associated with lower all-cause mortality (HR 0.65, 95%CI [0.52, 0.80], p < 0.001), but higher in-hospital mortality (OR 2.04, 95%CI [1.04, 4.01], p = 0.039).

CONCLUSION

In this cohort, relevant CAD was not associated with worse outcomes and should therefore not be considered a contraindication for LuTx. Nonetheless, cardiovascular events in CAD patients highlight the necessity of control of cardiovascular risk factors and a structured cardiac follow-up.

The Evaluation and Management of Coronary Artery Disease in the Lung Transplant Patient

Lung transplantation can greatly improve quality of life and extend survival in those with end-stage lung disease. In order to derive the maximal benefit from such a procedure, patients must be carefully selected and be otherwise healthy enough to survive a high-risk surgery and sometimes prolonged immunosuppressive therapy following surgery. Patients therefore must be critically assessed prior to being listed for transplantation with close attention paid towards assessment of cardiovascular health and operative risk. One of the biggest dictators of this is coronary artery disease. In this review article, we discuss the assessment and management of coronary artery disease in the potential lung transplant candidate.

Lung transplant survival with past and concomitant cardiac revascularization

BACKGROUND

Coronary artery disease is common among lung transplant (LTx) candidates and has historically been viewed as a contraindication to the procedure. Survival outcomes of lung transplant recipients with concomitant coronary artery disease who had prior or perioperative revascularization remain a topic of conversation.

METHODS

A retrospective analysis of all single and double lung transplant patients from Feb, 2012 to Aug, 2021 at a single center was performed (n = 880). Patients were split into 4 groups: (1) those who received a preoperative percutaneous coronary intervention, (2) those who received preoperative coronary artery bypass grafting, (3) those who received coronary artery bypass grafting during transplantation, and (4) those who had lung transplantation without revascularization. Groups were compared for demographics, surgical procedure, and survival outcomes using STATA Inc. A p value< 0.05 was considered significant.

RESULTS

Most patients receiving LTx were male and white. Pump type (p = 0.810), total ischemic time (p = 0.994), warm ischemic time (p = 0.479), length of stay (p = 0.751), and lung allocation score (p = 0.332) were not significantly different between the four groups. The no revascularization group was younger than the other groups (p<0.01). The diagnosis of Idiopathic Pulmonary Fibrosis was predominant in all groups except the no revascularization group. The pre-coronary artery bypass grafting group had a higher portion of single LTx procedures (p = 0.014). Kaplan-Meier analysis showed no significantly different survival rates after post-LTx between the groups (p = 0.471). Cox Regression analysis showed diagnosis significantly impacted survival rates (p 0.009).

CONCLUSIONS

Preoperative or intraoperative revascularization did not affect survival outcomes in lung transplant patients. Selected patients with coronary artery disease may benefit when intervened during lung transplant procedures.

Reoperative CABG in a patient with prior concomitant lung transplantation and two-vessel CABG

BACKGROUND

Lung transplants (LTx) are being offered to increasingly older patients, and as a result, more concomitant coronary artery disease is being encountered in LTx candidates. While concurrent coronary artery bypass grafting (CABG) and LTx have become more common, the long-term considerations of reoperative CABG in patients following CABG with concomitant LTx are not fully understood.

CASE PRESENTATION

A 75-year-old man with a history of bilateral LTx and concomitant CABG X 2 15 years prior presented to the emergency room with tachycardia and chest discomfort radiating to the left upper extremity. Emergent coronary angiography revealed severe three-vessel coronary artery disease with two occluded saphenous vein grafts, severe distal obtuse marginal (OM) and left circumflex disease, a collateralized chronic total occlusion of the mid LAD, and tortuosity of the proximal right innominate artery. The patient underwent a complex redo sternotomy and CABG X 2 due to dense adhesions in the mediastinum and pleura bilaterally. The postoperative course was complicated by left leg SVG harvest site cellulitis treated with IV antibiotics and hypervolemia treated with diuresis. The patient was discharged postoperatively on day 13.

DISCUSSION

To our knowledge, this is the first reported successful reoperative CABG in a patient with a history of concomitant LTx and CABG. This case demonstrates feasibility, though additional caution is required due to the technical complexity and risk of immunosuppression in such complex patients.

Lung transplantation for COPD/pulmonary emphysema

COPD and α-1 antitrypsin deficiency emphysema remain one of the major indications for lung transplantation. If all other treatment possibilities are exhausted or not possible (including rehabilitation, oxygen therapy, noninvasive ventilation, lung volume reduction), patients may qualify for lung transplantation. Strict selection criteria are implemented with a lot of relative and absolute contraindications. Because of an ongoing donor shortage, only a minority of endstage COPD patients will finally get transplanted. The procedure may involve a single or a double lung transplantation, dependent on the experience of the centre, the waiting list, the availability of donor lungs and the patient's risk-benefit ratio. In general, the life expectancy as well as the health-related quality of life after lung transplantation for COPD are usually increased, and may be somewhat better after double compared with single lung transplantation. Several specific complications can be encountered, such as the development of solid organ cancer and chronic lung allograft dysfunction, which develops in up to 50% of patients within 5 years of their transplant and has a major impact on long-term survival, because of the current inefficient treatment modalities.

Association of cardiac disease with the risk of post-lung transplantation mortality in Chinese recipients aged over 65 years

The current organ allocation rules prioritize elderly and urgent patients on the lung transplantation (LT) waiting list. A steady increase in the threshold at which age is taken into consideration for LT has been observed. This retrospective cohort study recruited 166 lung transplant recipients aged ≽ 65 years between January 2016 and October 2020 in the largest LT center in China. In the cohort, subgroups of patients aged 65-70 years (111 recipients, group 65-70) and ≽ 70 years (55 recipients, group ≽ 70) were included. Group D restrictive lung disease was the main indication of a lung transplant in recipients over 65 years. A significantly higher percentage of coronary artery stenosis was observed in the group ≽ 70 (30.9% vs. 14.4% in group 65-70, P = 0.014). ECMO bridging to LT was performed in 5.4% (group 65-70) and 7.3% (group ≽ 70) of patients. Kaplan-Meier estimates showed that recipients with cardiac abnormalities had a significantly increased risk of mortality. After adjusting for potential confounders, cardiac abnormality was shown to be independently associated with the increased risk of post-LT mortality (HR 6.37, P = 0.0060). Our result showed that LT can be performed in candidates with an advanced age and can provide life-extending benefits.

Adding complexity to complexity: The role of concomitant cardiac surgery in lung transplantation

Outcomes of lung transplantation have greatly improved over recent years. While patients with concomitant cardiac pathology used to be excluded from lung transplant, today, most of these cardiac conditions can be addressed safely and effectively. Interventional techniques should be preferred. Lung transplant performed by cardiac surgeons allows for concomitant interventions.

Lung transplantation and concomitant cardiac surgical procedures: A systematic review and meta-analysis

BACKGROUND

Lung transplantation is an effective treatment option for end-stage lung diseases. In some cases, these patients may also have underlying cardiac disease which may require surgical intervention before or during transplantation. Concomitant cardiac surgery may often be preferred, as reduced lung function precludes these patients from pre-transplant surgery. Our meta-analysis sought to examine the impact of lung transplantation paired with concomitant cardiac surgery on long-term mortality.

METHODS

We conducted a systematic review of the MEDLINE, Embase, and Cochrane databases. Our primary outcome was overall mortality. Secondary outcomes included length of stay (LOS) in hospital and serious postoperative complication rates. We used a meta-analytic model to determine the differences in the above outcomes between patients who underwent lung transplantation with or without concomitant cardiac surgery.

RESULTS

Out of the 1876 articles screened, 7 met our pre-determined inclusion criteria. Lung transplantation with concomitant cardiac surgery was not associated with increased mortality compared to lung transplantation alone (hazard ratio = 1.02; 95% confidence interval [CI] = 0.80-1.31; I²  = 0%; p = .99). LOS in hospital was not significantly different between groups (standardized mean difference = 0.32; 95% CI = -0.91 to 1.55). Postoperative complication rates were also reported but not analyzed due to missing data.

CONCLUSIONS

There was no significant difference in mortality rates in patients undergoing lung transplantation with or without concomitant cardiac surgery at 1, 3, and 5 years. However, postoperative complication rates were higher in the concomitant group. The decision to perform concomitant procedures should be tailored to each patient's clinical condition.

Lung transplantation and severe coronary artery disease: results from a single-centre experience

OBJECTIVES

The management of severe coronary artery disease at the time of lung transplantation remains a challenge. We analyzed the short- and long-term-outcomes of lung transplant recipients with severe coronary artery disease.

METHODS

Records of adult patients transplanted at our institution between April 2010 and February 2021 were retrospectively reviewed. Severe coronary artery disease was defined by coronary stenosis ≥70% (main stem ≥50%) at the coronary angiography performed before or at the time of listing. Patient characteristics, perioperative- and long-term-outcomes were compared between patients with and without severe coronary artery disease.

RESULTS

Among 896 lung-transplanted patients who had undergone a coronary angiography before transplantation, 77 (8.5%) showed severe coronary artery disease, the remaining 819 (91.5%) did not. Patients with severe coronary artery disease were older (p < 0.0001), more often male (p < 0.0001) and were transplanted more often for pulmonary fibrosis (p = 0.0007). The median (interquartile range) follow-up was 46 (20-76) months. At the Cox multivariable analysis severe coronary artery disease was not associated with mortality. Patients with pretransplant percutaneous transluminal coronary angioplasty and patients with coronary artery bypass graft surgery concomitant to transplantation had equivalent survival compared to patients without severe coronary artery disease (p = 0.513, p = 0.556).

CONCLUSIONS

Severe coronary artery disease was not associated with decreased survival after lung transplantation. Concomitant coronary artery bypass graft surgery and pretransplant percutaneous transluminal coronary angioplasty can be used for revascularization.

A systematic review and meta-analysis of coronary artery disease and revascularization in lung transplant patients

Coronary artery disease (CAD) is common in candidates for lung transplantation (LTx) and has historically been considered a relative contraindication to transplantation. We look to review the outcomes of LTx in patients with CAD and determine the optimum revascularization strategy in LTx candidates. PubMed, Medline and Web of Science were systematically searched by three authors for articles comparing the outcomes of LTx in patients with CAD and receiving coronary revascularization. In total 1668 articles were screened and 12 were included in this review.Preexisting CAD in LTx recipients was not associated with significantly increased postoperative morbidity or mortality. The pooled estimates of mortality rate at 1, 3 and 5 years indicated significantly inferior survival in LTx recipients with a prior history of coronary artery bypass grafting (CABG) [odds ratio (OR), 1.84; 95% confidence interval (CI), 1.53-2.22; P < 0.00001; I2 = 0%; OR, 1.52; 95% CI, 1.21-1.91; P = 0.0003; I2 = 0%; OR, 1.62; 95% CI, 1.13-2.33; P = 0.008; I2 = 71%, respectively). However, contemporary literature suggests that survival rates in LTx recipients with CAD that received revascularization either by percutaneous coronary intervention (PCI), previous or concomitant CABG, are similar to patients who did not receive revascularization. Trends in postoperative morbidity favored CABG in the rates of myocardial infarction and repeat revascularization, whereas rates of stroke favored PCI. The composite results of this study support the consideration of patients with CAD or previous coronary revascularization for LTx. Prospective, randomized controlled trials with consistent patient populations and outcomes reporting are required to fully elucidate the optimum revascularization strategy in LTx candidates.

Recipient selection, timing of referral, and listing for lung transplantation

Recipient selection for lung transplantation is a balance between providing access to transplantation to maximum patients, while utilizing this limited resource in the most optimal way. This review summarizes the current literature and recommendations about referral, listing, and evaluation of lung transplant candidates, with a focus on patients considered to have high risk characteristics.

Bilateral sequential lung transplantation: technical aspects

The surgical technique for lung transplantation has evolved dramatically over the last three decades. Significant improvements in short term outcomes in the early years of lung transplantation were due, in large part, to techniques developed to reduce airway anastomotic complications in single lung transplantation. Following development of the technique of en bloc double lung transplantation, evolution to the bilateral sequential technique further reduced airway complications for double lung transplantation. More recently, some programs have utilized the en bloc double lung transplant technique with bronchial artery revascularization to aid airway healing and potentially improve short- and long-term outcomes. The experience with bronchial artery revascularization remains limited to a few series, with the technique having not been widely adopted by most lung transplant programs. With the implementation of priority allocations schemes in many countries, patients with higher risk profiles are being prioritized for transplantation which results in more complex procedures in fragile recipients with multiple comorbidities. This includes the increased need for concomitant cardiac procedures as well as performing lung transplantation after prior cardiothoracic surgery. Different surgical approaches have been described for bilateral sequential lung transplantation with or without intra-operative mechanical circulatory support (MCS), such as sternotomy, clamshell (bilateral anterior thoracotomies with transverse sternotomy), and bilateral thoracotomy incisions. Herein, we aim, not only to describe the various surgical approaches for double lung transplantation, but to provide a comprehensive review of other aspects related to the recipient pathology and different anatomical variants as well as handling technical challenges that might be encountered during the procedure.

Current trends in candidate selection, contraindications, and indications for lung transplantation

Lung transplantation is an established treatment option that can improve quality of life and prolong survival for select patients diagnosed with end-stage lung disease. Given the gaps in organ donation and failures to make effective use of available organs, careful selection of candidates for lung transplant remains one of the most important considerations of the transplant community. Toward this end, we briefly reviewed recent trends in pretransplant evaluation, candidate selection, organ allocation, and organ preservation techniques. Since the latest consensus statement regarding appropriate selection of lung transplant candidates, many advances in the science and practice of lung transplantation have emerged and influenced our perspective of 'contraindications' to transplant. These advances have made it increasingly possible to pursue lung transplant in patients with risk factors for decreased survival-namely, older recipient age, increased body mass index, previous chest surgery, poorer nutritional status, and presence of chronic infection, cardiovascular disease, or extrapulmonary comorbid conditions. Therefore, we reviewed the updated evidence demonstrating the prognostic impact of these risk factors in lung transplant recipients. Lastly, we reviewed the salient evidence for current trends in disease-specific indications for lung transplantation, such as chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, cystic fibrosis, emphysema due to alpha-1 antitrypsin deficiency, and pulmonary arterial hypertension, among other less common end-stage diseases. Overall, lung transplant remains an exciting field with considerable hope for patients as they experience remarkable improvements in quality of life and survival in the modern era.

Lung Transplant Recipients With Prior Coronary Artery Bypass Grafting Are at Increased Risk of Death and Early Perioperative Hemorrhage

Prior coronary artery bypass grafting (CABG) has been considered a relative contraindication to lung transplantation due to the atherosclerotic disease burden and technical challenges. We hypothesized that lung transplant recipients with prior CABG have increased mortality compared to recipients without prior CABG. Further, the causes of death are different for lung transplant recipients with prior CABG vs without CABG. The Scientific Registry of Transplant Recipients database was queried to define the survival and causes of death of lung transplant recipients with or without CABG during the Lung Allocation Score era from May 5, 2005 to December 31, 2015. The primary end-points were all-cause mortality at 1 year and 5 years, as well as mortality due to major causes of death. This retrospective study cohort included a total of 13,064 lung transplant recipients, of whom 319 patients had previously undergone CABG, representing 2.4% of all transplants. Patients without prior CABG were more likely to have undergone bilateral lung transplantation compared to those with prior CABG (61.2 % vs 15.7%, P < 0.001). Among patients with prior CABG, single right lung transplant was most common. Overall patient survival at 1 year was 76.8% for lung transplant recipients with prior CABG and 85.4% for patients without prior CABG. Freedom from death due to graft failure at 1 and 5 years in patients with a prior CABG was 93.1% and 76.2% respectively, cardiac and/or cerebrovascular disease 96.2% and 88.5% respectively, and hemorrhage 97.9% and 97.5% respectively. In a multivariate Cox regression model utilizing time-dependent coefficients for recipient age, prior CABG, among several other risk factors, was associated with increased mortality within 1 year. Prior CABG is associated with short- and long-term mortality in lung transplant recipients with history of CABG despite the majority of these patients undergoing single lung transplantation vs bilateral lung transplantation. Graft failure and/or pulmonary causes are the most common cause of death regardless of whether or not the lung transplant recipient had prior CABG, but patients with prior CABG are at increased risk of death due to graft failure, cardiac or cerebrovascular disease, and hemorrhage.

Successful bridge to lung transplantation with transcatheter aortic valve replacement

End-stage lung disease and advanced cardiac conditions are frequently seen together and represent a clinical dilemma. Even though both issues may be amenable to surgical management, combining lung transplant with surgical valve repair is rarely done and theoretically associated with increased morbidity and mortality risks, especially in elderly patients. Here, we describe 2 patients presenting with end-stage lung disease and significant aortic stenosis who were successfully bridged to lung transplant via transcatheter aortic valve replacement. Patient 1 was a 66-year-old man who underwent a double lung transplant 56 days after transcatheter aortic valve replacement. Patient 2 was a 70-year-old man who underwent a single right lung transplant 103 days after transcatheter aortic valve replacement. Both patients had uneventful postoperative courses and are alive at the 1-year time point with excellent performance status. This report suggests that transcatheter aortic valve replacement may favorably impact lung transplant candidacy for patients with end-stage lung disease in the setting of severe aortic stenosis, likely representing a better alternative to concomitant aortic valve replacement and lung transplant in elderly patients.

Coronary artery disease in lung transplant patients

Coronary artery disease (CAD) is a pathology often found in patients with end-stage lung disease. Although in the past CAD might have been considered an absolute contraindication, modern revascularization techniques have helped increase the number of transplants performed in this population. However, discrepancies in the guidelines for perioperative evaluation and risk mitigation strategies for the ischemic cardiac burden are present in the current literature. This is a review of the available data regarding perioperative evaluation, revascularization tactics, postoperative management, and survival rate that patients with different grades of coronary artery disease present after lung transplantation.

Harvesting left internal thoracic artery via clamshell incision for coronary bypass and lung transplant

Concomitant lung transplantation and coronary artery bypass grafting operation became more prevalent over the last decade due to the advanced age of recipients. Median sternotomy approach is traditionally used when internal thoracic artery is utilized. Here we report a technique of harvesting the left internal thoracic artery via a clamshell incision for a combined coronary artery bypass and bilateral lung transplant operation in a 71-year-old male with terminal respiratory failure and coronary artery disease.

Developments in lung transplantation over the past decade

With an improved median survival of 6.2 years, lung transplantation has become an increasingly acceptable treatment option for end-stage lung disease. Besides survival benefit, improvement of quality of life is achieved in the vast majority of patients. Many developments have taken place in the field of lung transplantation over the past decade. Broadened indication criteria and bridging techniques for patients awaiting lung transplantation have led to increased waiting lists and changes in allocation schemes worldwide. Moreover, the use of previously unacceptable donor lungs for lung transplantation has increased, with donations from donors after cardiac death, donors with increasing age and donors with positive smoking status extending the donor pool substantially. Use of ex vivo lung perfusion further increased the number of lungs suitable for lung transplantation. Nonetheless, the use of these previously unacceptable lungs did not have detrimental effects on survival and long-term graft outcomes, and has decreased waiting list mortality. To further improve long-term outcomes, strategies have been proposed to modify chronic lung allograft dysfunction progression and minimise toxic immunosuppressive effects. This review summarises the developments in clinical lung transplantation over the past decade.

Lung transplantation for idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is characterized by relentlessly progressive lung function impairment that is consistently fatal in the absence of lung transplantation, as no curative pharmacological treatment exists. The pace of progression varies across patients, and acute life-threatening exacerbations occur unpredictably, causing further sharp drops in lung function. Recently introduced antifibrotic agents slow the pace of disease progression and may improve survival but fail to stop the fibrotic process. Moreover, the magnitude and kinetics of the response to these drugs cannot be predicted in the individual patient. These characteristics require that lung transplantation be considered early in the course of the disease. However, given the shortage of donor lungs, lung transplantation must be carefully targeted to those patients most likely to benefit. Current guidelines for lung transplantation listing may need reappraisal in the light of recent treatment advances. Patients with IPF often have multiple comorbidities such as coronary heart disease, frailty, and gastro-oesophageal reflux disease (GERD). Consequently, extensive screening for and effective treatment of concomitant conditions is crucial to appropriate candidate selection and outcome optimisation. A multidisciplinary approach is mandatory. Pulmonologists with expertise in IPF must work closely with lung transplant teams. Careful consideration must be given to preoperative optimisation, surgical technique, and pulmonary rehabilitation to produce the best post-transplantation outcomes.

Chronic Obstructive Pulmonary Disease and the Optimal Timing of Lung Transplantation

Chronic obstructive pulmonary disease (COPD) accounts for the largest proportion of respiratory deaths worldwide and was historically the leading indication for lung transplantation. The success of lung transplantation procedures is measured as survival benefit, calculated as survival with transplantation minus predicted survival without transplantation. In chronic obstructive pulmonary disease, it is difficult to show a clear and consistent survival benefit. Increasing knowledge of the risk factors, phenotypical heterogeneity, systemic manifestations, and their management helps improve our ability to select candidates and list those that will benefit the most from the procedure.

Coronary Artery Disease and Coronary Artery Bypass Grafting at the Time of Lung Transplantation Do Not Impact Overall Survival

BACKGROUND

Coronary artery disease (CAD) is common in lung transplant candidates and may require revascularization before or at the time of their transplant. We reviewed the survival of lung transplant recipients with CAD requiring surgical intervention (CAD-coronary artery bypass grafting [CABG]) and those who did not (CAD-NoCABG) at the time of transplant, compared to a cohort with no CAD (NoCAD).

METHODS

We conducted a retrospective cohort study of adult patients transplanted in our program between 2004 and 2013. Our primary outcome was the association between 3-way CAD status (CAD-CABG, CAD-NoCABG, NoCAD) and overall retransplant-free survival via proportional hazards modeling, adjusting for age, gender, and transplant indication. Secondary endpoints included 1-year survival, survival by Kaplan-Meier analysis, duration of ventilation, intensive care unit stay, and hospitalization.

RESULTS

A total of 333 patients underwent transplant during the study timeframe. A total of 24 (7%) had CAD requiring CABG, 82 (25%) had CAD not requiring CABG, and the remaining 227 had no CAD. The 3-way CAD status was not associated with overall retransplant-free survival after adjustment for age, gender, and transplant indication. Duration of mechanical ventilation, intensive care unit stay and hospitalization were longer in both CAD groups compared with the NoCAD group.

CONCLUSIONS

CAD status does not impact overall retransplant-free survival, despite greater perioperative complexity. Prospective studies comparing treatment strategies in these patient groups are warranted.

Lung transplantation for idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease with a poor prognosis. Lung transplantation is the only intervention shown to increase life expectancy for patients with IPF, but it is associated with disease-specific challenges. In this Review, we discuss the importance of a proactive approach to the management of IPF comorbidities, including gastro-oesophageal reflux, pulmonary hypertension, coronary artery disease, and malignancy. With a donor pool too small to meet demand and unacceptably high mortality on transplant waiting lists, we discuss different systems used internationally to facilitate organ allocation. We explore the rapidly evolving landscape of transplantation for patients with IPF with regards to antifibrotic therapy, technological advances in extracorporeal life support, advances in understanding of the genetics of the disease, and the importance of a holistic multidisciplinary approach to care. Finally, we consider potential advances over the next decade that are envisaged to improve transplantation outcomes in patients with advanced IPF.

Heart rate variability and baroreflex sensitivity in bilateral lung transplant recipients

The effects of lung afferents denervation on cardiovascular regulation can be assessed on bilateral lung transplantation patients. The high-frequency component of heart rate variability is known to be synchronous with breathing frequency. Then, if heart beat is neurally modulated by breathing frequency, we may expect disappearance of high frequency of heart rate variability in bilateral lung transplantation patients. On 11 patients and 11 matching healthy controls, we measured R-R interval (electrocardiography), blood pressure (Portapres^® ) and breathing frequency (ultrasonic device) in supine rest, during 10-min free breathing, 10-min cadenced breathing (0·25 Hz) and 5-min handgrip. We analysed heart rate variability and spontaneous variability of arterial blood pressure, by power spectral analysis, and baroreflex sensitivity, by the sequence method. Concerning heart rate variability, with respect to controls, transplant recipients had lower total power and lower low- and high-frequency power. The low-frequency/high-frequency ratio was higher. Concerning systolic, diastolic and mean arterial pressure variability, transplant recipients had lower total power (only for cadenced breathing), low frequency and low-frequency/high-frequency ratio during free and cadenced breathing. Baroreflex sensitivity was decreased. Denervated lungs induced strong heart rate variability reduction. The higher low-frequency/high-frequency ratio suggested that the total power drop was mostly due to high frequency. These results support the hypothesis that neural modulation from lung afferents contributes to the high frequency of heart rate variability.

Staging of Bilateral Lung Transplantation for High-Risk Patients With Interstitial Lung Disease: One Lung at a Time

The choice of a single or bilateral lung transplant for interstitial lung disease (ILD) is controversial, as surgical risk, long-term survival and organ allocation are competing factors. In an effort to balance risk and benefit, our center adopted a staged bilateral lung transplant approach for higher surgical risk ILD patients where the patient has a single lung transplant followed by a second single transplant at a later date. We sought to understand the surgical risk, organ allocation and early outcomes of these staged bilateral recipients as a group and in comparison to matched single and bilateral recipients. Our analysis demonstrates that staged bilateral lung transplant recipients (n = 12) have a higher lung allocation score (LAS), lower pulmonary function tests and a lower glomerular filtration rate prior to the first transplant compared to the second (p < 0.01). There was a shorter length of hospital stay for the second transplant (p = 0.02). The staged bilateral compared to the single and bilateral case-matched controls had comparable short-term survival (p = 0.20) and pulmonary function tests at 1 year. There was a higher incidence of renal injury in the conventional bilateral group compared to the single and staged bilateral groups. The staged bilateral procedure is a viable option in select ILD patients.

Lung transplantation following coronary artery bypass surgery-improved outcomes following single-lung transplant

BACKGROUND

Prior coronary artery bypass grafting (CABG) has been a contraindication to lung transplantation (LTx) because of disease severity and technical considerations. Although patients increasingly are being referred for and receiving LTx, whether it should remain a contraindication is unknown. We sought to define the prevalence of LTx after CABG and determine the effect on outcomes.

METHODS

The United Network for Organ Sharing Standard Transplant Analysis and Research data set was queried during the period 2004-2013 for adult LTx patients, as prior CABG became a mandatory reporting field in 2004. The primary end-points were 30-day and 1-, 3-, and 5-year survivals.

RESULTS

The study cohort included 14,791 patients, of whom 292 patients had previously undergone CABG (single left, n = 68; single right, n = 181; bilateral, n = 43), representing 2% of all transplants. For the entire cohort, 30-day survival was 97%, and survival at 1, 3, and 5 years was 88%, 79%, and 74%. CABG was a predictor of mortality at all time points, with hazard ratios ranging from 1.97 (confidence interval, 1.23-3.16; p < 0.01) at 30 days to 1.38 (confidence interval, 1.12-1.69; p < 0.01) at 5 years. When stratified by type of transplant, CABG strongly predicted mortality at all time points for patients receiving bilateral, but not single, transplants.

CONCLUSIONS

Although LTx after CABG is uncommon, it is increasingly performed in the current era. Single right LTx is the most common procedure performed in patients with prior CABG. CABG before LTx is an independent predictor of mortality at all time points and is driven by increased mortality in patients receiving bilateral LTx.

A global perspective of lung transplantation: Part 1 - Recipient selection and choice of procedure

Lung transplantation has grown considerably in recent years and its availability has spread to an expanding number of countries worldwide. Importantly, survival has also steadily improved, making this an increasingly viable procedure for patients with end-stage lung disease and limited life expectancy. In this first of a series of articles, recipient selection and type of transplant operation are reviewed. Pulmonary fibrotic disorders are now the most indication in the U.S., followed by chronic obstructive pulmonary disease and cystic fibrosis. Transplant centers have liberalized criteria to include older and more critically ill candidates. A careful, systematic, multi-disciplinary selection process is critical in identifying potential barriers that may increase risk and optimize long-term outcomes.

Lung transplantation in chronic obstructive pulmonary disease: patient selection and special considerations

Chronic obstructive pulmonary disease (COPD) is a leading cause of mortality and morbidity. Lung transplantation is one of the few treatments available for end-stage COPD with the potential to improve survival and quality of life. The selection of candidates and timing of listing present challenges, as COPD tends to progress fairly slowly, and survival after lung transplantation remains limited. Though the natural course of COPD is difficult to predict, the use of assessments of functional status and multivariable indices such as the BODE index can help identify which patients with COPD are at increased risk for mortality, and hence which are more likely to benefit from lung transplantation. Patients with COPD can undergo either single or bilateral lung transplantation. Although many studies suggest better long-term survival with bilateral lung transplant, especially in younger patients, this continues to be debated, and definitive recommendations about this cannot be made. Patients may be more susceptible to particular complications of transplant for COPD, including native lung hyperinflation, and development of lung cancer.

Preoperative mild-to-moderate coronary artery disease does not affect long-term outcomes of lung transplantation

BACKGROUND

Coronary artery disease has a high prevalence among lung transplant recipients and has historically been a contraindication to transplant at many institutions. In patients with mild-to-moderate coronary artery disease (Mod-CAD) undergoing lung transplant, outcomes are not well defined.

METHODS

All patients who underwent pulmonary transplantation from January 1996 through November 2010 with pretransplant coronary angiogram were included in our study. Recipients of multivisceral, redo, and lobar lung transplants and those who underwent pretransplant coronary revascularization were excluded. Patients were grouped into Mod-CAD or no-coronary artery disease group (No-CAD). Primary end point was overall survival. Secondary end points were 30-day events and the need for posttransplant coronary revascularization.

RESULTS

Approximately 539 patients were included in the study: 362 in the No-CAD, 177 in the Mod-CAD group. Patients with Mod-CAD were predominantly male, older, and had a higher body mass index. No difference in either perioperative morbidity and mortality (Mod-CAD, 4.2% vs. No-CAD 3.3%, P=0.705) or late overall mortality was shown between groups. Mod-CAD patients had a shorter hospitalization (median: 12 days vs. 14 days, P=0.009) and required a higher rate of late coronary revascularization procedures (PCI: Mod-CAD vs. No-CAD, 0.3% vs. 4.0%, P=0.0035; CABG: Mod-CAD vs. No-CAD, 0.3% vs. 2.3%, P=0.0411).

CONCLUSIONS

Mod-CAD does not appear to be associated with increased perioperative morbidity or decreased survival after transplant. Coronary artery disease may worsen and require coronary revascularization in patients with risk factors for disease progression. In these patients, close follow-up and screening for progression of coronary artery disease may help prevent late cardiac morbidity.