eComment: How to define operability in pulmonary hypertension secondary to congenital heart disease?

Rosic et al. report the surgical management of a 54-year-old patient with an atrial septal defect (ASD) using a unidirectional fenestrated atrial septal patch, allowing for right-to-left shunting in the postoperative period.

The patient had a favourable outcome, although the mean pulmonary artery pressure decreased from 30 mmHg preoperatively to 26 mmHg at follow-up. This patient thus still has pulmonary hypertension (PH), and requires treatment. This begs the question: is it a success? In a retrospective study of patients with pulmonary artery hypertension (PAH) with follow-up to 20 years, patients with Eisenmenger syndrome and unoperated simple congenital cardiac defects overall have the best survival (87-86% at 20 years), much better than any other subgroup and particularly better than those with PAH after surgical repair of congenital heart disease (36%), even though their quality of life remains poor. Long-term outcomes are the key question, and unfortunately no long-term data are available. Once the defect is closed, a pathophysiological situation more similar to idiopathic PAH is obtained, which is associated with much worse long-term outcomes. This case illustrates several unsolved issues in patients with PAH-CHD: what are the criteria for operability? How should they be defined? Although novel biomarkers capable of defining the degree of pulmonary vascular disease (PVD), such as circulating endothelial cells or micro-RNAs, are currently being investigated, haemodynamic criteria based on right heart catheterization and vasoreactivity remain the gold standard, however flawed they may be. What are the long-term outcomes after surgical repair of CHD with PAH? Until what age should patients be referred for surgical repair, and in particular will a patient 50 years or older benefit from closing the hole? Furthermore, if right ventricular failure after closing the ASD is feared, how should the right ventricle be protected? Atrioseptostomy or a fenestrated atrial patch provides diastolic decompression of the RV providing a decrease in right atrial and end-diastolic right ventricular pressure, an increase in cardiac output at the expense of systemic oxygen desaturation, and an increase in left ventricular end-diastolic pressure that can overwhelm the left ventricle if the fenestration is oversized. If systolic failure due to PAH is suspected, a post-tricuspid shunt (Pott's) seems to be a better solution that can provide systolic decompression and facilitate the difficult post-operative period, while maintaining adequate oxygen saturation to the upper body and coronary circulation. This sounds like a schizophrenic dilemma: we aim at closing the ASD when there is high pulmonary blood flow and PAH is present, but suggest to open an atrial communication in case of severe PAH. Finally, although Rosic et al. should be commended for the favourable early outcome, it should be noted that current guidelines recommend preoperative testing with iNO in patients with an indexed PVR of 6-9 WU/m² (as opposed to nitroglycerin in this report), and that calcium channel blocker treatment for PAH-CHD is contraindicated after surgical repair, and treatment with endothelin receptor antagonists, phosphodiesterase inhibitors or prostacyclin are recommended in case of persistent or recurrent PAH after shunt closure.

Conflict of interest: Dr Beghetti has served as consultant, steering committee and/or advisory board member for Actelion Pharmaceuticals Ltd., Bayer-Healthcare, Eli Lilly, GlaxoSmithKline, and Pfizer. The other authors report no conflict.

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