Background: Pulmonary Thromboembolism (PE) is an under recognized and potentially fatal entity having varied manifestations.

Methods: We conducted a prospective observational study of cases of pulmonary embolism (PE) proven on Computed tomography pulmonary angiography (CTPA) admitted to the pulmonary medicine department of our tertiary care centre. These cases were analysed to study the profile with respect to demography, clinical features and radiological manifestations.

Results: Our study included 70 cases of PE. Our study showed a male preponderance with increased prevalence of pulmonary embolism after the age of forty years. The risk factors for PE were immobilization (46%), smoking (30%) andclinical signs of deep venous thrombosis (DVT) (23%). The comorbidities associated were hypertension, diabetes mellitus and lung malignancy. Common presenting symptoms were dyspnoea,cough, chest pain and haemoptysis. Common examination findings were tachycardia,desaturation and signs of DVT. On chest radiography, 27% of our patients had a normal chest radiograph. The abnormal findings included consolidation (16%), pleural effusion (14.3%) and cardiomegaly (14.3%).Commonelectrocardiography (ECG) findings weresinus tachycardia (94.3%), Signs of right ventricular dominance and S1Q3T3 pattern. DVT was present in 26% patients. CTPA findings revealed thatright pulmonary artery (21%) was most commonly involved followed by bilateral segmental arteries (14.3%).

Conclusion: PE is commonly associated with high risk factors like smoking, immobilisation and history of DVT. Clinical and radiological features are heterogeneous and a high index of suspicion and CTPA is essential for a timely diagnosis.

Venous thromboembolism (VTE) is a spectrum of thromboembolic phenomena clinically presenting as deep venous thrombosis (DVT) or Pulmonary Embolism (PE). However, the risk of death related to the initial acute episode or to recurrent PE is profoundly greater than in that with DVT[1]. Acute PE is globally the third most frequent acute cardiovascular syndrome after myocardial infarction and stroke [2]. The overall annual incidence of PE is approximately 1 to 2 cases per 1000 persons [3].Even with rapid advances in the diagnosis and management of PE, it still continues to be underreported. There is paucity of literature on this entity and most of the material is limited to autopsy reports and short case series [4]. The clinical presentations could be variegated and diagnosis could be missed unless a high index of suspicion is maintained.  Evaluating the possibility of PE in an individual patient is of utmost importance, not only for the interpretation of the diagnostic test results but also for the selection of an appropriate management strategy [5].This is extremely pertinent as the case fatality in symptomatic PE is 10% in the first hour and that a hospital mortality secondary to untreated PE can be reduced from 30% to nearly 8% if treated timely [6]. The milestone studies done in this area include the PIOPED 1 and PIOPED 2 trials. These provide lucidity about the clinical demonstrations and the diagnostic strategy [7, 8]. However there is dearth of literature on Indian studies done on this crucial topic [3]. Hence we conducted this study to assess the profile and presentation of this entity in a tertiary care hospital from Western India. 

The present study was a prospective observational study conducted at the Pulmonary medicine department of our tertiary care hospital after Institutional ethics committee (IEC) permission.The study was conducted during the period– 1stJune2017 to 31st May 2019, over a period of 24 months. All cases of PE suspected on the basis of clinical presentationandsimplified Wells pre-test probability score[9]were evaluated by a Computed tomography Pulmonary angiography (CTPA).Cases confirmedto have a PE were included in the study after obtaining a written informed consent.Patients with absence PE on CTPA were excluded from the study. Detailed history and clinical examination of each case was done. The demographic data like age and sex, history of comorbidities and presence of risk factors for VTEin form of history of immobilization, history of DVT, history of smoking, recent surgery and history of malignancy were noted. Chest radiograph (CXR), electrocardiograph (ECG), a two-dimensional echocardiography (2Decho) and a bilateral lower limb venous Doppler was performed and the findings were noted. CTPA findings were noted.Data was analyzed and presented as percentages and mean.

A total of70 patients were included in the study. The mean age observed in our study was 48.14 yearswith the predominant age group being 40 to 50 years (Table ). We observed a higher prevalence of the male gender i.e. 42 patients (60%) than female 28 patients (40%) (Table 1). The most common risk factor for PE was immobilization in 32 (46%) followed by smoking in 21 (30%). Clinical signs and symptoms of DVTwere present in 16 (23%) patients while there was a past history of DVT in 13 (18.6 %). There was history of previous or active malignancy in 13 (18.6 %) patients. History of recent surgery was present in 3 (4.2%) patients. (Table 2) The most common comorbidities associated with PE in our study were systemic hypertension in 17(24%) followed by Diabetes Mellitus10 (14%), lung malignancy 10 (14%) and pulmonary tuberculosis 4 (5.7%). The most common symptom noted were dyspnea68 (97%) followed by cough 64 (91.5%), fever39 (56%) chest pain 38 (54.2%),and hemoptysis 8(11.5%).(Table 3) Most common finding on general examination were tachycardia observed in 66 (94.3%), hypoxia in 42 (60%), signs of DVT in 16 (23%),pallorin 12 (17.1%), systolic blood pressure below 90 in 6 (8.5%) andraised jugular venous pressure (JVP) in 5 (7.1%) respectively. (Table 4)The most common respiratory system examination finding werecrackles in 19 (27%),decreased breath sound in 13 (18.5%) and rhonchi in 4 (5.7%). Respiratory system examination was normal in 34(48.55) patients.  Cardiovascular examination was normal in 57(81.4 %), while the abnormal findings included loud P2 in 7(10%), and murmur in tricuspid area 6 (8.5%).(Table 5)

Simplified wells score more than 1 is consideredpositive for pulmonary embolism9. All had a positive Well’s score. The mean Well’s score was 2.19. The average of simplified wells score was high in younger age group than in elderly. On assessment of CXR patterns, the findings noted were consolidation in 11(16%),pleural effusion in 10 (14.3%), cardiomegaly in 10 (14.3%),fibrotic or nodular opacity in 10 (14.3%), pulmonary infiltrates in 3 (4.2%), cavitary changes in 2 (2.8%), hydropneumothorax in 2 (2.8%) and pleural thickening in 1 (1.4%).The classical radiological sign of Hamptons hump was present only in 2 patients (2.8%). (Table 6)The common ECG finding noted were sinus tachycardia (94.3%), Signs of Right ventricular dominance were P pulmonale, RBBB and Right axis noted in 7 (10%), 4 (4.2%)and 7 (10%) respectively. Specific finding of pulmonary embolism S1Q3T3 was present only in 10 (14.2%) of patients. T wave inversion was noted in 14 (20%) of patients. ECG was normal in 5.7% of patients. (Table 7). The 2Decho findings suggestive of mild pulmonary hypertension (PH), Moderate PH, Severe PH were observed in 23 (33%), 15 (21.4%) and 16 (23%) respectively. A dilated right atrium and right ventricle was found in 14 (20%) patients. (Table 8). Incidence of DVT in unilateral right and left lower limb was 6 (8.6%), and 7 (10 %) 8.6%. Bilateral DVT was present in 3 (4.2%). Varicosity without DVT was evident in 2 (2.8%) patients.(Table 9) CTPAfindings revealed that the Right pulmonary artery (PA) was most commonly involved in 15 (21%) cases followed by bilateral segmental arteryinvolvement in 10 (14.3%). Right segmental and left lobar arteries had equal incidence of thrombosis as seen in 9 (13%) each.  Similar observation was noted in Bilateral PA 7 (10%) and Right lobar PA 7 (10%).(table 10)

Table 1. Age and Gender distribution of Pulmonary Embolism
 

Table 2 Risk factor for pulmonary embolism 
 

Table 3. Symptomatology of PE
 

Table 4. General examination of patients of pulmonary embolism    
 

Table 5. Systemic Examination of patients of pulmonary embolism 
 

Table 6. Chest radiograph findings in pulmonary embolism 
 

Table 7 Electrocardiographic (ECG) findings in patients of Pulmonary Embolism. 
 

Table 8: Two dimensional Echocardiography findings of subjects of pulmonary embolism 
 

Table 9. Venous Doppler of lower limbs of Patients 
 

Table 10. Computed tomographic pulmonary angiography patterns of pulmonary vessel involvement 
 

Table 11. Computed tomographic pulmonary Thrombus

Our prospective study gives an overview on the clinical and radiological profile of a group of 70 hospitalized patients in a tertiary care institute in Western India with a CTPA confirmed diagnosis of acute PE. The mean age observed in our study was 48.14 years which is lower than most studies quoted in literature like the ICOPER[10], MAPPET[11] and JASPER12 studies where it was 62.3  ,63.5 and 60 years respectively. However in some Indian studiesreported similar predominance in the  younger age group3,13. Most studies show a tendency towards equal gender distribution. In our study we observed a higher prevalence of the male gender which was also reported in the MAPPET10study and in the Indian study done by Lolly et al[3].This could be attributed to the delay in seeking medical attention by the female patients in a developing country like ours. The major risk factors for VTE include recent immobilization, surgery, recent trauma, smoking and a previous history of DVT or a current DVT. These have been elucidated by various studies in literature including the PIOPED study. [3,8,10,11]The most frequent risk factors for PE encountered in our study were immobilization in 32 (46%) followed by smoking in 21 (30%). Clinical signs and symptoms of DVT were present in 16 (23%) patients while there was a past history of DVT in 13 (18.6 %).These findings are consistent with other studies[3,12]. The analysisunderlines the fact that an active search for these risk factors should be undertaken in all patients with clinical suspicion of VTE as they are modifiable to a huge extent. Our patients harboured comorbid conditions in form of hypertension in 24% and diabetes mellitus in 14%. This is similar to a study performed by Mohsin et al[14].

The most common symptom of PE encountered in our study was dyspneawhich was present in 97% of our patients. This concurs with most studies done on the topic3,13. In our study, chest pain was found in 54.2% patients, similar to the findings of ICOPER[10]and JaSPER12 studies. Fever was observed in 56% of our patients, similar to the 14% reported in all the subjects studied by PIOPED study7. This highlights the importance of keeping PE as one of the differentials in a case of fever with acute respiratory symptoms and remembrance of the fact that the presence of fever may also hint inflammation rather than infection [15]. In the present study, on general examination we found tachycardia as the most common sign where is consistent with otherstudies[11], 16. Hypoxia was noted in 60% of our patients, which is lesser than in a study done by Al Dandan O et al[17] . Hypotension was documented in only 8.5% of our patients as compared to studies by Kasper W et[11] and M. Nakamura et al[12] where incidence was higher 34% and 36% respectively. The discrepancies in these findings related to hypoxia and hypotension could be due to the selection bias as our study. Ours was performed at a pulmonary medicinedepartment rather than any emergency medicine or cardiology department.

The major role of chest radiography in cases of suspected PE is to exclude competing diagnoses and to evaluate the pulmonary parenchyma. In the present study, we found chest radiographic changes in 72.85% of patients similar to that seen in the ICOPER11 study.  The ICOPER study showed that pleural effusion was present in 23%, and areas of pulmonary infiltrates in 17%. Our findings identified pleural effusion in 14%, and pulmonary infiltrates in 4.3% of patients.Specific ECG findings help to suspect possibility of PE. Our study showed sinus tachycardia as the most prevalent ECG abnormality which is similar to others studies[16,17]. The S1Q3T3 pattern was observed in 14.2% of our patients. This classic sign of PE appears to be less common contrary to the belief16.Echocardiography serves a valuable role in the diagnostic approach to PE. Under appropriate clinical circumstances, the detection of unexplained right ventricular volume or pressure overload should suggest the possibility of embolism and lead to confirmatory testing.A distinct   echocardiographic   pattern involving   akinesia of the mid-free right ventricular wall with apical sparing has been described[18]as the Mc Connells sign.The overall sensitivity of transthoracic echocardiography in pulmonary embolism approximates 50%[19].Therefore, it cannot be considered a primary diagnostic technique. However, consideration can be given to its use in the subset of patients with suspected massive pulmonary embolism who are too ill for transportation or who have an absolute contraindication to the administration of a contrast agent for CTPA .The percentage of patients with RV dysfunction on echocardiography was 20%,while severe pulmonary hypertension was found in 23% of patients. This prevalence is lesser than in the study done by CalwinDavidsingh et al[16]. This again can be attributed to the referral and selection bias in a pulmonary medicine department. 2 D Echocardiography was normal in 23% of our patients emphasizing the fact that normal 2 D Echo does not exclude the diagnosis of pulmonary embolism.The employment of CTPA is a landmark development in the diagnosis of PE on account of its high sensitivity and specificity particularly in detecting thrombi in the main lobar and segmental levels.[20] CTPA has now become the gold standard test and has virtually replaced the erstwhile invasive means of diagnosis[8]. The analysis of location of the thrombus on a CTPA revealed that in 57.4

We reiterate that PE was a common but often overlooked cause of mortality and morbidity in patients hospitalized not only with respiratory symptoms but also for other surgical or medical illnesses in our center. The identification of risk factors was crucial to prevent the recurrence or progression of VTE to PE. The common risk factors observed like smoking and immobilisation were to a great extent modifiable. Chest radiography and ECG were common tools available for screening but could be normal in a huge proportion of patients.  A high degree of clinical suspicion with rational application of diagnostic tools based on the pre-test probability scores was vital for definitive diagnosis. Early clinic-radiological recognition and timely CTPA and 2 Decho helped improve diagnostics and further therapeutics in this potentially fatal condition at our center.