Idiopathic Pulmonary Fibrosis for Cardiologists: Differential Diagnosis, Cardiovascular Comorbidities, and Patient Management

Abstract

The presence of rare comorbidities in patients with cardiovascular disease (CVD) presents a diagnostic challenge to cardiologists. In evaluating these patients, cardiologists are faced with a unique opportunity to shorten diagnosis times and direct patients towards correct treatment pathways. Idiopathic pulmonary fibrosis (IPF), a type of interstitial lung disease (ILD), is an example of a rare disease where patients frequently demonstrate comorbid CVD. Both CVD and IPF most commonly affect a similar patient demographic: men over the age of 60 years with a history of smoking. Moreover, IPF and heart failure (HF) share a number of symptoms. As a result, patients with IPF can be misdiagnosed with HF and vice versa. This article aims to increase awareness of IPF among cardiologists, providing an overview for cardiologists on the differential diagnosis of IPF from HF, and describing the signs and symptoms that would warrant referral to a pulmonologist with expertise in ILD. Once patients with IPF have received a diagnosis, cardiologists can have an important role in managing patients who are candidates for a lung transplant or those who develop pulmonary hypertension (PH). Group 3 PH is one of the most common cardiovascular complications diagnosed in patients with IPF, its prevalence varying between reports but most often cited as between 30% and 50%. This review summarizes the current knowledge on Group 3 PH in IPF, discusses data from clinical trials assessing treatments for Group 1 PH in patients with IPF, and highlights that treatment guidelines recommend against these therapies in IPF. Finally, this article provides the cardiologist with an overview on the use of the two approved treatments for IPF, the antifibrotics pirfenidone and nintedanib, in patients with IPF and CVD comorbidities. Conversely, the impact of treatments for CVD comorbidities on patients with IPF is also discussed.Funding: F. Hoffmann-La Roche, Ltd.Plain Language Summary: Plain language summary available for this article.

Keywords: Antifibrotic; Cardiology; Comorbidities; Diagnosis; Idiopathic pulmonary fibrosis; Nintedanib; Pirfenidone; Pulmonary hypertension; Rare disease; Treatment.

Fig. 1

Classification of ILDs [–123]. EP eosinophilic pneumonia, LAM lymphangioleiomyomatosis, LCH Langerhans cell histiocytosis. ^aClinical, radiological, pathological. This figure is based on previously published information. Permission for re-use has been granted for: Ryerson and Collard [122], https://journals.lww.com/co-pulmonarymedicine/Abstract/2013/09000/Update_on_the_diagnosis_and_classification_of_ILD.8.aspx. Reprinted with permission of the American Thoracic Society. Copyright © [2018] American Thoracic Society [121, 123].

Fig. 2

Diagnostic algorithm for IPF from 2018 ATS/ERS/JRS/ALAT guidelines [1]. ALAT Latin American Thoracic Society, ATS American Thoracic Society, BAL bronchoalveolar lavage, ERS European Respiratory Society, HRCT high-resolution computed tomography, IPF idiopathic pulmonary fibrosis, JRS Japanese Respiratory Society, MDD multidisciplinary discussion, UIP usual interstitial pneumonia. ^aSurgical lung biopsy is not indicated in patients at high risk for intra-, peri-, or post-operative complications. Reprinted with permission of the American Thoracic Society. Copyright © [2018] American Thoracic Society [1]. The American Journal of Respiratory and Critical Care Medicine is an official journal of the American Thoracic Society