Delays in Diagnosis of Acute Pulmonary Thromboembolism : Clinical Outcomes and Risk Factors

Acute pulmonary thromboembolism is a common and potentially lethal disease. There is limited information about clinical importance of the delay in pulmonary embolism diagnosis. Between January 2009 and December 2010, consecutive 189 patients with PTE were enrolled to this retrospective study. Varriables including age, sex, educational level, smoking, Wells scores, symptoms, embolism types, clinical and radiological findings were analyzed for delay in diagnosis. Study group consisted of 104 (55%) female and 85 (45%) male patients. The mean age of the group was 57,95 (range 19-88) years. The mean time to presantation or patient delay was 7.9± 15.2 (median 3 days; range, 1-120) days. Diagnostic delay caused by initial misdiagnosis of the health care providers was 0.5± 3,9 (median 0; range 0-45) days. Seventy (37,04%) patients had a delay in diagnosis longer than seven days after onset of symptoms of pulmonary embolism. Current smokers, patients with low Wells scores(≤4) and having non spesific CT pulmonary angiographic findings for PTE at the first admission associated with delay in diagnosis in the present study (p<0.05). Massive type of embolism was associated with mortality (p=0,020). Delay in diagnosis in PTE may increase mortality and massive embolism should be monitored carefully.


INTRODUCTION
Clinically significant venous thromboembolism (VTE) is a common cardiopulmonary and vascular illness affecting 1 to 2 of every 1000 adults per year (1,2).The mortality rate of acute pulmonary embolism (PE) is 17% during the first year after diagnosis (3).In terms of pathologic diagnosis, an embolus is acute if it is situated centrally within the vascular lumen or if it occludes and causes distention of the involved vessel.Immobilization, surgical interventions, trauma and cancer frequently trigger venous thrombosis.Delays between onset of symptoms and diagnosis are common in PTE.Earlier diagnoses of deep vein thrombosis (DVT) and PE may reduce the morbidity and mortality associated with VTE (4).Some studies about PE reported a correlation between disease severity and early presentation (5,6).Despite diagnostic advances, delays in PE diagnosis remain problematic (7).In this study, we investigated the effects of risk factors on diagnostic delays and also the relationship between diagnostic delays and the mortality in PE.

Study design and patients
This retrospective study based on the medical records of all hospitalized patients with PE diagnosis between January 2009 and December 2010.The multidisciplinary investigation was conducted at Department of Chest Disease of Ondokuz Mayıs University Hospital, which is a referral center for PE patients.The study was approved by the local ethical committee.All of consecutive patients with PE were enrolled to study and assessed in terms of demography, clinical evaluation, laboratory finding, risk factors for PE, diagnostic tests and diagnotic delay representing the date between onset of symptoms and diagnosis.In case of coexisting illnesses, the day on which the symptoms of sudden dyspnea, chest pain or syncope attributed to PE were accepted as the date of symptom onset retrospectively.The time from the onset of symptoms to diagnosis was defined as "time to diagnosis".Diagnostic delay was defined as diagnosis of PE more than 7 days after symptom onset.In the analysis of outcomes, we evaluated patients dead (mortality) during the hospitalization, after their discharge and survivors that had completed at least12 months of surveillance.A pulmonary embolus is characterized as massive when it involves both pulmonary arteries or when it results in hemodynamic compromise and presenting with a systolic arterial pressure less than 90 mmHg (8).

Statistical analysis
Results are given as mean ± SD, odds ratio and 95% confidence interval.P values less than 0.05 were considered statistically significant.The Mann-Whitney U and ki-square tests were used for the statistical analysis of the correlations between delays, mortality, and clinical data.Possible risk factors for diagnostic delays were an-alyzed using multivariate logistic regression.Collected data were analyzed using SPSS.15 statistical software.

Demographic and general data
One hundred and eighty nine patients constituted the complete group of study with the mean age of 57.95 (range 19-88) years, 104 (55%) of them were female and 85 (45%) of them were male.Fifty (26.45%) of patients were illiterate and one hundred and thirty four (73.54%) had primary or high school education.Fiftyeight (30.68%) of them were current smokers during admission.

Concomittant diseases and risk factors
Several patients had previous pathological conditions: heart failure and hypertension was present in 32(16.9%)patients and chronic respiratory disease in 15(8%) patients.A history of previous venous thromboembolism was reported in 16 (8.5%)patients (deep venous thrombosis in 7 patients, pulmonary embolism in 9 patients).History of immobilazation with or without operation in last three months was noted as the most common risk factor among the study group with a number of 68(36%) patients.Three of the patients had Behçet disease, six had cancer and three were pregnant as a risk cofactor.

Diagnostic methods
Diagnosis was made by means of thoracic computerized tomographic (CT) angiography and ventilationperfussion (V-P) scintigraphy.CT angiography clearly showed venous thrombosis in 81 (42.85%) patients.V-P scintigraphic results correlated with clinical and radiological findings were used in diagnosis of remaining 109 (57.15%) patients.Color doppler ultrasonography revealed the deep vein thrombosis of lower extremities in 86 (45.50%) patients.

Delay in diagnosis
Delays in the diagnosis of PE represented both delays between the onset of symptoms and the receipt of medical attention, and between the initial medical evaluation and confirmatory diagnostic testing.After onset of symptoms of pulmonary embolism, 70 (37.04%)patients had a delay longer than seven days.A total of 119 (62.96%) patients were diagnosed earlier; 29 (15,34%) patients in first twenty four hour and 90 (47.61%) pa-tients in seven days.The mean time in patient delays occured by late presentation of the patients which was 7.9±15.2(median 3; range 1-120) days.Diagnostic delay caused by initial misdiagnosis of the health care providers was 0.5± 3,9(median 0; range 0-45) days.Delay in diagnosis was found more frequent among the patients with low clinical risk scores according to Wells (Canadian) classification than the other group with high risk scores (p=0,002), (Table -1 and 3

Table 2 .
Major symptoms and signs of the patients with PTE

Table - 3
. Characteristics of the patients with PE according to risk groups in the first clinical evaluation *Statistically significant, group-A included the patients with Wells risk scores <4, group-B included the patients with Wells risk scores >4 at first admission to emergency.PPA: pressure of pulmonary arteries, V-P: ventilation and perfusion.fromthe PTE and the mean delaying time in diagnosis was 13.21 (range 1-60) days in this group which was longer than the time of survived patients.Ten (52.63%) of the 19 patients who died from PTE had a delay in diagnosis longer than seven days.This was a higher rate than the patients who survived.Another result of the present study was a higher mortality in massive embolism than the submassive or nonmassive forms of PE (p=0.020).