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

Introduction: 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 (SpO₂) and were followed up to 40 months. CSD was considered as SpO₂ <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, χ² =.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.