Preoperative cardiac variables of diastolic dysfunction and clinical outcomes in lung transplant recipients

Impact of Pre-Transplant Left Ventricular Diastolic Pressure on Primary Graft Dysfunction after Lung Transplantation: A Narrative Review

Lung transplantation (LT) constitutes the last therapeutic option for selected patients with end-stage respiratory disease. Primary graft dysfunction (PGD) is a form of severe lung injury, occurring in the first 72 h following LT and constitutes the most common cause of early death after LT. The presence of pulmonary hypertension (PH) has been reported to favor PGD development, with a negative impact on patients' outcomes while complicating medical management. Although several studies have suggested a potential association between pre-LT left ventricular diastolic dysfunction (LVDD) and PGD occurrence, the underlying mechanisms of such an association remain elusive. Importantly, the heterogeneity of the study protocols and the various inclusion criteria used to define the diastolic dysfunction in those patients prevents solid conclusions from being drawn. In this review, we aim at summarizing PGD mechanisms, risk factors, and diagnostic criteria, with a further focus on the interplay between LVDD and PGD development. Finally, we explore the predictive value of several diastolic dysfunction diagnostic parameters to predict PGD occurrence and severity.

Impact of lung transplantation on diastolic dysfunction in recipients with pretransplant pulmonary hypertension

OBJECTIVE

Pulmonary hypertension can cause left ventricular diastolic dysfunction through ventricular interdependence. Moreover, diastolic dysfunction has been linked to adverse outcomes after lung transplant. The impact of lung transplant on diastolic dysfunction in recipients with pretransplant pulmonary hypertension is not defined. In this cohort, we aimed to assess the prevalence of diastolic dysfunction, the change in diastolic dysfunction after lung transplant, and the impact of diastolic dysfunction on lung transplant outcomes.

METHODS

In a large, single-center database from January 2011 to September 2021, single or bilateral lung transplant recipients with pulmonary hypertension (mean pulmonary artery pressure > 20 mm Hg) were retrospectively identified. Those without a pre- or post-transplant echocardiogram within 1 year were excluded. Diastolic dysfunction was diagnosed and graded according to the American Society of Echocardiography 2016 guideline on assessment of diastolic dysfunction (present, absent, indeterminate). McNemar's test was used to examine association between diastolic dysfunction pre- and post-transplant. Kaplan-Meier and Cox regression analysis were used to assess associations between pre-lung transplant diastolic dysfunction and post-lung transplant 1-year outcomes, including mortality, major adverse cardiac events, and bronchiolitis obliterans syndrome grade 1 or higher-free survival.

RESULTS

Of 476 primary lung transplant recipients, 205 with pulmonary hypertension formed the study cohort (mean age, 56.6 ± 11.9 years, men 61.5%, mean pulmonary artery pressure 30.5 ± 9.8 mm Hg, left ventricular ejection fraction < 55% 9 [4.3%]). Pretransplant, diastolic dysfunction was present in 93 patients (45.4%) (grade I = 8, II = 84, III = 1), absent in 16 patients (7.8%), and indeterminate in 89 patients (43.4%), and 7 patients (3.4%) had missing data. Post-transplant, diastolic dysfunction was present in 7 patients (3.4%) (grade I = 2, II = 5, III = 0), absent in 164 patients (80.0%), and indeterminate in 15 patients (7.3%), and 19 patients (9.3%) had missing data. For those with diastolic dysfunction grades in both time periods (n = 180), there was a significant decrease in diastolic dysfunction post-transplant (148/169 patients with resolved diastolic dysfunction; McNemar's test P < .001). Pretransplant diastolic dysfunction was not associated with major adverse cardiac events (hazard ratio [HR], 1.08, 95% CI, 0.72-1.62; P = .71), bronchiolitis obliterans syndrome-free survival (HR, 0.67, 95% CI, 0.39-1.56; P = .15), or mortality (HR, 0.70, 95% CI, 0.33-1.46; P = .34) at 1 year.

CONCLUSIONS

Diastolic dysfunction is highly prevalent in lung transplant candidates with normal left ventricular systolic function and pulmonary hypertension, and resolves in most patients after lung transplant regardless of patient characteristics. Pre-lung transplant diastolic dysfunction was not associated with adverse lung or cardiac outcomes after lung transplant. Collectively, these findings suggest that the presence of diastolic dysfunction in lung transplant recipients with pulmonary hypertension has no prognostic significance, and as such diastolic dysfunction and the associated clinical syndrome of heart failure with preserved ejection fraction should not be considered a relative contraindication to lung transplant in such patients.

Effect of left ventricular diastolic dysfunction on development of primary graft dysfunction after lung transplant

PURPOSE OF REVIEW

Primary graft dysfunction (PGD) is one of the most common complications after lung transplant and is associated with significant early and late morbidity and mortality. The cause of primary graft dysfunction is often multifactorial involving patient, donor, and operational factors. Diastolic dysfunction is increasingly recognized as an important risk factor for development of PGD after lung transplant and here we examine recent evidence on the topic.

RECENT FINDINGS

Patients with end-stage lung disease are more likely to suffer from cardiovascular disease including diastolic dysfunction. PGD as result of ischemia-reperfusion injury after lung transplant is exacerbated by increased left atrial pressure and pulmonary venous congestion impacted by diastolic dysfunction. Recent studies on relationship between diastolic dysfunction and PGD after lung transplant show that patients with diastolic dysfunction are more likely to develop PGD with worse survival outcome and complicated hospital course.

SUMMARY

Patients with diastolic dysfunction is more likely to suffer from PGD after lung transplant. From the lung transplant candidate selection to perioperative and posttransplant care, thorough evaluation and documentation diastolic dysfunction to guide patient care are imperative.

Diastolic Dysfunction Increases the Risk of Primary Graft Dysfunction after Lung Transplant

RATIONALE

Primary graft dysfunction (PGD) is a significant cause of early morbidity and mortality after lung transplant and is characterized by severe hypoxemia and infiltrates in the allograft. The pathogenesis of PGD involves ischemia-reperfusion injury. However, subclinical increases in pulmonary venous pressure due to left ventricular diastolic dysfunction may contribute by exacerbating capillary leak.

OBJECTIVES

To determine whether a higher ratio of early mitral inflow velocity (E) to early diastolic mitral annular velocity (é), indicative of worse left ventricular diastolic function, is associated with a higher risk of PGD.

METHODS

We performed a retrospective cohort study of patients in the Lung Transplant Outcomes Group who underwent bilateral lung transplant at our institution between 2004 and 2014 for interstitial lung disease, chronic obstructive pulmonary disease, or pulmonary arterial hypertension. Transthoracic echocardiograms obtained during evaluation for transplant listing were analyzed for E/é and other measures of diastolic function. PGD was defined as PaO2/FiO2 less than or equal to 200 with allograft infiltrates at 48 or 72 hours after reperfusion. The association between E/é and PGD was assessed with multivariable logistic regression.

MEASUREMENTS AND MAIN RESULTS

After adjustment for recipient age, body mass index, mean pulmonary arterial pressure, and pretransplant diagnosis, higher E/é and E/é greater than 8 were associated with an increased risk of PGD (E/é odds ratio, 1.93; 95% confidence interval, 1.02-3.64; P = 0.04; E/é >8 odds ratio, 5.29; 95% confidence interval, 1.40-20.01; P = 0.01).

CONCLUSIONS

Differences in left ventricular diastolic function may contribute to the development of PGD. Future trials are needed to determine whether optimization of left ventricular diastolic function reduces the risk of PGD.