Safety of exertional desaturation in idiopathic pulmonary fibrosis: An electrocardiography study

Exertional desaturation is a cardinal manifestation of idiopathic pulmonary fibrosis (IPF) which raises concerns for serious complications. Objectives To evaluate the safety of clinically significant desaturation (CSD) during exercise and to assess whether abnormal electrocardiographic (ECG) changes are associated with mortality and hospitalizations in patients with IPF. Methods Thirty‐four IPF patients (68 ± 8 years, 35% women) underwent maximal cycle cardiopulmonary exercise testing (CPET) using 12‐lead ECG and pulse oximetry (SpO 2 ) and were followed up to 40 months. CSD was considered as SpO 2 <95% or decline from baseline ≥5%. The level of agreement between abnormal ECG changes and CSD was evaluated. Risks for mortality and hospitalizations were assessed in relation to abnormal ECG changes. Results All patients completed CPET without adverse events or life‐threating ECG changes. Comparing rest to exercise conditions, the prevalence of mild ventricular arrhythmia rose from 3% to 18% ( P  = .025) and CSD rose from 21% to 79% ( P  < .001). There was no agreement between the prevalence of arrhythmia and CSD during exercise (kappa = −.065, χ 2  = .72, P  = .40). A trend for lower prevalence was observed in ST‐T segment deviation during exercise. Resting and exercise ECG abnormalities were not associated with mortality or hospitalizations during the follow‐up. Conclusions CSD during CPET was not associated with ventricular arrhythmias, ischemia, or complications in patients with IPF. These findings suggest that CPET is generally a safe procedure for IPF, although carefully monitoring for signs and symptoms including ECG is strongly recommended. Additional research is warranted to confirm these results.