Lung Function in Patients with Congenital Heart Disease: Prevalence, Severity, and Correlation to Diagnosis

Objectives: Since restrictive lung function is an independent predictor of mortality (1) in congenital heart disease (CHD), evaluation of lung function in patients with CHD should be performed as part of the follow-up routine; analysis includes description of prevalence, type of lung disease and severity and its correlation with the underlying diagnosis.

Methods: A total of 411 patients with CHD aged 6 to 66 years (mean: 29.3 ± 13.6 years) underwent spirometry between 2012 and 2015. The ratio of forced expiratory volume in the first second to forced vital capacity (FEV1/VC Ratio) and vital capacity (VC) were measured. Cut-off: restrictive lung function: VC < 80% of predicted, obstructive lung function FEV1/VC < 0.8.

Results: Patients with normal lung function: 29.8%, restrictive lung function: 30.5%, obstructive lung function: 23.4%, mixed-type impairment: 16.3%. A decreased vital capacity correlates significantly with the number of thoracotomies (r = − 0.429; p = 0.0001) and the underlying diagnosis p< 0.0001. Highest prevalence of restrictive lung defects was found in patients with univentricular anatomy, complex cyanotic heart defects and Fallot Tetralogy (TOF). Most patients with obstructive lung defect were found in patients with Ebstein Anomaly. Least impaired were patients with transposition of great arteries (TGA), unrelated to the surgical technique (atrial or arterial switch operation [ASO]).

Fig. 1 [Vital Capacity in CHD] Median and quartiles of VC% in different CHD.

Conclusion: Patients with univentricular hearts, complex cyanotic anatomy and TOF are most likely affected by restrictive lung function. Since this is a known and independent risk factor for mortality (Alonso-Gonzalez et al., 2013), it is recommendable to routinely perform spirometry especially on these patients to determine individual risk by impairment or decline in lung function.