Pulmonary artery Hypertension (PAH) is a common complication of Interstitial Lung Diseases (ILDs), Particularly in Idiopathic Pulmonary Fibrosis and ILD Associated with Connective Tissue Disease [1].

Pulmonary Hypertension (PH), defined as a resting mean pulmonary Artery Pressure (PAP) ≥25 mmHg, is an important complication of several interstitial lung diseases (ILDs) and can adversely affect patient outcome [1,2].

Clinically, PH may impose dyspnoea, fatigue and exercise limitation, symptoms which are also characteristic for ILDs. Consequently, the diagnosis of PH may be missed in ILD patients until signs of right heart failure develop [3].

Patients with PAH often complain of shortness of breath with physical activity that gradually worsens over time. Patients may also experience the symptoms like chest pain, fainting episodes, difficulty breathing when lying flat, swelling of the ankles etc. In ILD patients, pulmonary hypertension is usually suspected when these symptoms are out of proportion to the severity of the patient's ILD [4].

There is paucity of studies on the Pulmonary Artery Hypertension (PAH) and its association with association of clinical symptoms and signs among patients diagnosed with Interstitial Lung Diseases (ILD), in this hilly area of northern India. The present study was done to evaluate the association of clinical symptoms and signs with Pulmonary Artery Hypertension (PAH) among Interstitial Lung Diseases (ILDs) patients.

Aims and Objectives

To study the association of clinical symptoms and signs with Pulmonary Artery Hypertension (PAH) among Interstitial Lung Diseases (ILDs) patients.

The present study was conducted at Indira Gandhi Medical College, Shimla which is a tertiary care center of Himachal Pradesh, located in North India in Asian Continent and covers the majority of the population of this state. All consecutive patients of Interstitial Lung Diseases (ILDs), attending the outpatient services of the Department of Pulmonary Medicine, IGMC Shimla from July 2018 to June 2019 were screened for enrolment in the study. All types of ILDs were enrolled in the study.

Inclusion Criteria:

• Stable ILD patients: diagnosis of ILD according to ATS/ERS guidelines based on an overall assessment of High-Resolution Computed Tomography (HRCT) scan, lung function tests, (bronchoscopy and biopsy, if available)

• Age >18 years, written consent

Exclusion Criteria:

• Subjects with evidence of left heart disease, Chronic kidney disease, Liver disease

• Chronic lung diseases other than ILDs

• Patients with HIV

• Pregnant

Patients presenting with respiratory symptoms such as cough, shortness of breath and diagnosed cases of ILD were evaluated. 

All consecutive ILD patients were subjected to focused history and physical examination as structured questionnaire record information related to; Demographics, Duration of ILD, Pulmonary Artery Hypertension (PAH) and its Association with clinical symptoms and signs etc.

The data was collected, entered in the MS Excel sheet and analyzed using Epi info V7 software. Continuous variables were reported as mean ± SD or median and interquartile range depending on the distribution of the variables. Categorical variables were recorded as counts and percentages. Differences between means of continuous variables were compared using the unpaired student’s’ test. A p-value of <0.05 was considered as statistically significant. 

Among the study population, 50 patients 27 (54%) were female and 23 (46%) were male. The mean age of the study population was 57.821+5.03years. The mean age of males and females was 62.561+3.84 years and 53.771+5.07 years respectively. The mean duration of symptoms of ILD was 3.034+2.62 years. There was no significant difference between males and females regarding the duration of illness (2.76+2.46 years versus 3.39+2.77 years, p=0.40) (Table 1).

Pulmonary Artery Hypertension (PAH) was by derived Pulmonary Flow Acceleration Time formula (PFAT). Those who had Mean Pulmonary Artery Pressure (MPAP) >25 mmHG was diagnosed as PAH case. Out of 50 patients, 44 (88%) had PAH.

Table 1: Age and Gender Distribution of the Study Population (N=50)

Table 2: Association of Clinical Symptoms and Signs with PAH (Table 6)

Among 50 patients, majority were dyspnoea of gradeII 9(43.3%) and gradeIII 21(47.7%) with PH group with a p value of 0.35. Out of 50 patients, 43 (97.73%) patients had a cough, with PH group with a p-value of 0.88. Out of 50 patients, 17 (34%) had chest pain among these 17 (38.84%) patients had PH with a p -value of 0.06. Out of 50 patients, 16 (32%) had Exertional syncope, 13 (29.55%) were in PH group, with a p-value of 0.28. Out of 50 patients 32 (64%), patients had clubbing, 30 (68.18%) patients were in the PH group, with a p- value of 0.11.Out of 50 patients, 11(22%) had raised JVP, 9(20.45%) patients were in the PH group, with a p-value of p of 0.25.Out of 50 patients, 29 (58%) had velcro crackle on occultation, 27 (61.36%) were in the PH group, with ap- value of 0.19 (Table 2).

The association of ILD with clinical symptoms and signs was analyzed to determine the risk determinants of PAH.

The mean age of the study population was 57.821+5.03 with male and female mean age 62.561+3.84 and 53.77+15.07 respectively. Females were more than male and younger with a mean duration of ILD of 3.034±2.62 years. A similar finding was also reported in the study conducted by Agarwal. et al. [5] in the ILD registry of Indian data, it was reported that ILDs occur at a younger age compared to the western countries and females are affected more [6].

In our study, the majority of the patients had grade II and grade III of dyspnea among the PH group. Agarwal et al. [5] in their study majority of patients had grade 3 and grade 4 in PH group, in our study various types of ILD were included but in their study, only IPF was there and the sample was small. 

In our study, the majority of patients had a cough in the PH group. In the various study, it was mentioned cough is associated with PH and ILD. In our study, the majority of patients did not have Exertional chest pain and exertional syncope. 

In our study majority of patients had clubbing and Velcro crackles PH group 68.18% and 61% respectively. Agarwal et al. [5] reported similar observations. In our 
study majority of patients did not have raised JVP, only 20% had raised JVP. In our study, the mean Hemoglobin (HB) was 15.61+1.5g% among patients with a PH group with a p-value of .0006. In our study, the majority of the patients had a chest x-ray feature of reticular shadow 70% (p=0.01). Agarwal R et al. [5] in their study reported a similar finding among 88.9%, in their study sample size was small and the study was done only among IPF patients.

There was very high prevalence of PAH among ILD Patients. Clinical sign and symptoms like dyspnoea, cough chest pain, exertional syncope, clubbing, raised JVP, velcro crackle was more prominent among patients of PAH as compared to those who didn’t had PAH. But there was no statistically difference among various clinical sign and symptoms.

Limitations of the Study

The small number of the population were included in this study represents a methodological limitation and study over a larger population is recommended.

1. Caminati, A., et al. "Pulmonary hypertension in chronic interstitial lung diseases." European Respiratory Review, vol. 22, no. 129, 2013, pp. 292–301.

2. Montani, D., et al. "Pulmonary arterial hypertension." Orphanet Journal of Rare Diseases, vol. 8, 2013, p. 97.

3. Behr, J. and J.H. Ryu. "Pulmonary hypertension in interstitial lung disease." European Respiratory Journal, vol. 31, 2008, pp. 1357–1367.

4. UCSF Health. "Pulmonary hypertension and interstitial lung disease." UCSF Health. 

5. Agarwal, R., et al. "Noninvasive estimation of clinically asymptomatic pulmonary hypertension in idiopathic pulmonary fibrosis." The Indian Journal of Chest Diseases & Allied Sciences, vol. 47, no. 4, 2005, pp. 267–271.

6. "Indian ILD Registry." Lung India, vol. 31, no. 4, Oct.–Dec. 2014, pp. 320–322.