***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: We have previously demonstrated that a clinical model can be safely used in a management strategy in patients with suspected pulmonary embolism ( PE ) . We sought to simplify the clinical model and determine a scoring system , that when combined with D-dimer results , would safely exclude PE without the need for other tests , in a large proportion of patients . We used a r and omly selected sample of 80 % of the patients that participated in a prospect i ve cohort study of patients with suspected PE to perform a logistic regression analysis on 40 clinical variables to create a simple clinical prediction rule . Cut points on the new rule were determined to create two scoring systems . In the first scoring system patients were classified as having low , moderate and high probability of PE with the proportions being similar to those determined in our original study . The second system was design ed to create two categories , PE likely and unlikely . The goal in the latter was that PE unlikely patients with a negative D-dimer result would have PE in less than 2 % of cases . The proportion of patients with PE in each category was determined overall and according to a positive or negative SimpliRED D-dimer result . After these determinations we applied the models to the remaining 20 % of patients as a validation of the results . The following seven variables and assigned scores ( in brackets ) were included in the clinical prediction rule : Clinical symptoms of DVT ( 3.0 ) , no alternative diagnosis ( 3.0 ) , heart rate > 100 ( 1.5 ) , immobilization or surgery in the previous four weeks ( 1.5 ) , previous DVT/PE ( 1.5 ) , hemoptysis ( 1.0 ) and malignancy ( 1.0 ) . Patients were considered low probability if the score was < 2.0 , moderate of the score was 2.0 to 6.0 and high if the score was over 6.0 . Pulmonary embolism unlikely was assigned to patients with scores < or = 4.0 and PE likely if the score was > 4.0 . 7.8 % of patients with scores of less than or equal to 4 had PE but if the D-dimer was negative in these patients the rate of PE was only 2.2 % ( 95 % CI = 1.0 % to 4.0 % ) in the derivation set and 1.7 % in the validation set . Importantly this combination occurred in 46 % of our study patients . A score of < 2.0 and a negative D-dimer results in a PE rate of 1.5 % ( 95 % CI = 0.4 % to 3.7 % ) in the derivation set and 2.7 % ( 95 % CI = 0.3 % to 9.0 % ) in the validation set and only occurred in 29 % of patients . The combination of a score < or = 4.0 by our simple clinical prediction rule and a negative SimpliRED D-Dimer result may safely exclude PE in a large proportion of patients with suspected PE The aim of this study was to prospect ively evaluate the accuracy of quantitative cardiac computed tomography ( CT ) parameters and two cardiac biomarkers ( N-terminal-pro-brain natriuretic peptide ( NT-pro-BNP ) and troponin I ) , alone and in combination , for predicting right ventricular dysfunction ( RVD ) in patients with acute pulmonary embolism . 557 consecutive patients with suspected pulmonary embolism underwent pulmonary CT angiography . Patients with pulmonary embolism also underwent echocardiography and NT-pro-BNP/troponin I serum level measurements . Three different CT measurements were obtained ( right ventricular (RV)/left ventricular (LV)axial , RV/LV4-CH and RV/LVvolume ) . CT measurements and NT-pro-BNP/troponin I serum levels were correlated with RVD at echocardiography . 77 patients with RVD showed significantly higher RV/LV ratios and NT-pro-BNP/troponin I levels compared to those without RVD ( RV/LVaxial 1.68±0.84 versus 1.00±0.21 ; RV/LV4-CH 1.52±0.45 versus 1.01±0.21 ; RV/LVvolume 1.97±0.53 versus 1.07±0.52 ; serum NT-pro-BNP 6,372±2,319 versus 1,032±1,559 ng·L−1 ; troponin I 0.18±0.41 versus 0.06±0.18 g·L−1 ) . The area under the curve for the detection of RVD of RV/LVaxial , RV/LV4-CH , RV/LVvolume , NT-pro-BNP and troponin I were 0.84 , 0.87 , 0.93 , 0.83 and 0.70 respectively . The combination of biomarkers and RV/LVvolume increased the AUC to 0.95 ( RV/LVvolume with NT-pro-BNP ) and 0.93 ( RV/LVvolume with troponin I ) . RV/LVvolume is the most accurate CT parameter for identifying patients with RVD . A combination of RV/LVvolume with NT-pro-BNP or troponin I measurements improves the diagnostic accuracy of either test alone AIMS We hypothesized that first-time submassive pulmonary embolism ( PE ) can cause persistent , significant cardiopulmonary problems , including right ventricular damage and worsened quality of life in patients with no prior cardiopulmonary disease . METHODS AND RESULTS We prospect ively enrolled 205 patients without end-stage comorbidity diagnosed with submassive PE ( systolic blood pressure always > 100 mmHg ) . Using explicit criteria , we identified a subgroup of 127 ' previously healthy ' patients who were free of cardiopulmonary disease or other disabling process . All patients had transthoracic echocardiography ( echo ) at the time of diagnosis . Six months later , survivors returned for repeat echo , 6 min walk distance  ( 6MWD ) , and a  quality -of-life survey .  We defined a significant cardiopulmonary problem as either : ( i ) abnormal RV on echo ( RV dilation or RV hypokinesis ) ; or ( ii ) NYHA score > II or a 6MWD < 330 m at 6 months . Of 127 study patients , five had inadequate echos , nine were lost to follow-up , and four died , leaving 109 with complete data . Of 109 patients , 45 ( 41 % ) had cardiopulmonary problems 6 months after PE : 18 of 109 ( 17 % ) had only an abnormal RV , 18 of 109 ( 17 % ) had only functional limitation , and nine of 109 ( 8 % ) had both . Twenty-two patients ( 20 % ) indicated at least one index of poor quality -of-life : health status worse , not currently shopping , or perceived need for oxygen at home .  Patients with cardiopulmonary problems demonstrated a significant decrease in SaO(2)% after 6MWD ( 97 + /- 1.3 pre-6MWD vs. 96 + /- 1.8 % post-6MWD , P = 0.004 by paired t-test ) . CONCLUSION Six months after first-time PE , 41 % of previously healthy patients had either an abnormal RV on echo , an NYHA score > II or a 6MWD < 330 m. Treatment studies of PE should include these persistent cardiopulmonary problems as study endpoints BACKGROUND When ultrasonography is used to investigate deep-vein thrombosis , serial testing is recommended for those who test negative initially . Serial testing is inconvenient for patients and costly . We aim ed to assess whether the calculation of pretest probability of deep-vein thrombosis , with a simple clinical model , could be used to improve the management of patients who present with suspected deep-vein thrombosis . METHODS Consecutive out patients with suspected deep-vein thrombosis had their pretest probability calculated with a clinical model . They then underwent compression ultrasound imaging of proximal veins of the legs . Patients at low pretest probability underwent a single ultrasound test . A negative ultrasound excluded the diagnosis of deep-vein thrombosis whereas a positive ultrasound was confirmed by venography . Patients at moderate pretest probability with a positive ultrasound were treated for deep-vein thrombosis whereas patients with an initial negative ultrasound underwent a single follow-up ultrasound 1 week later . Patients at high pretest probability with a positive ultrasound were treated whereas those with negative ultrasound underwent venography . All patients were followed up for 3 months for thromboembolic complications . FINDINGS 95 ( 16.0 % ) of all 593 patients had deep-vein thrombosis ; 3 % , 17 % , and 75 % of the patients with low , moderate , and high pretest probability , respectively , had deep-vein thrombosis . Ten of 329 patients with low pretest probability had the diagnosis confirmed , nine at initial testing and one at follow-up . 32 of 193 patients with moderate pretest probability had deep-vein thrombosis , three diagnosed by the serial ( 1 week ) test , and two during follow-up . 53 of 71 patients with high pretest probability had deep-vein thrombosis ( 49 by the initial ultrasound and four by venography ) . Only three ( 0.6 % ) of all 501 ( 95 % CI 0.1 - 1.8 ) patients diagnosed as not having deep-vein thrombosis had events during the 3-month follow-up . Overall only 33 ( 5.6 % ) of 593 patients required venography and serial testing was limited to 166 ( 28 % ) of 593 patients . INTERPRETATION Management of patients with suspected deep-vein thrombosis based on clinical probability and ultrasound of the proximal deep veins is safe and feasible . Our strategy reduced the need for serial ultrasound testing and reduced the rate of false-negative or false-positive ultrasound studies UNLABELLED Although ventilation/perfusion ( V/Q ) lung scintigraphy is a well-accepted and frequently performed procedure in the diagnosis of pulmonary embolism , there is growing controversy about its relevance , particularly due to the increasing competition between scintigraphy and CT . Even though comparative studies between both modalities have already been performed , their results were highly inconsistent . Remarkably , in most of those studies , conventional planar perfusion scans were compared with tomographic images acquired using state-of-the-art CT scanners-a study design that can not give impartial results . Hence , the aim of our study was a balanced comparison between V/Q lung scintigraphy and CT angiography using advanced imaging techniques for both modalities . METHODS A total of 83 patients with suspected pulmonary embolism were examined using V/Q lung scintigraphy in SPECT technique as well as 4-slice spiral CT . Ventilation scans were done using an ultrafine aerosol . Additionally , planar images in 8 views were extracted from the V/Q SPECT data sets . Two experienced referees assessed each of the 3 modalities . The final diagnosis was made at a consensus meeting while taking into account all of the imaging modalities , laboratory tests , clinical data , and evaluation of a follow-up period . RESULTS In the course of the consensus conference , pulmonary embolism was diagnosed in 37 of the 83 patients ( 44.6 % ) . Compared with planar scintigraphy , SPECT raised the number of detectable defects at the segmental level by 12.8 % ( + 11 defects ; P = 0.401 ) and at the subsegmental level by 82.6 % ( + 57 defects ; P < 0.01 ) . The sensitivity/specificity/accuracy of planar V/Q scintigraphy and V/Q SPECT was 0.76/0.85/0.81 and 0.97/0.91/0.94 , respectively , compared with 0.86/0.98/0.93 for multislice CT . CONCLUSION SPECT and ultrafine aerosols are technical advancements that can substantially improve lung scintigraphy . Using advanced imaging techniques , V/Q scintigraphy and multislice spiral CT both yield an excellent and , in all aspects , comparable diagnostic accuracy , with CT leading in specificity while SPECT shows a superior sensitivity . Even though planar lung scintigraphy yields satisfactory results for a nontomographic modality , it does not compare with tomographic imaging OBJECTIVE Many health care providers encounter patients with complaints of calf pain , swelling , chest pain , shortness of breath , and syncope after intense exercise . Unfortunately , these symptoms alone or in constellation could represent an underlying venous thromboembolism . A negative D-dimer can often exclude moderate-risk patients . We examined the change in D-dimer levels following strenuous exercise . METHODS In a prospect i ve study of 42 sailors , D-dimer levels were drawn before and after a workout that simulated the st and ardized Navy Physical Readiness Test . Data were analyzed using the Kruskal-Wallis and Kolmogorov-Smirnov tests . RESULTS No significant change was found between pre- and postexercise levels . CONCLUSION Findings indicate that neither level of conditioning , nor short , intense exercise affected D-dimer levels in participants who were considered extremely at low risk for thromboembolic disease . In essence , this allowed us to test the test , and therefore adds to our underst and ing of a screening tool used in the pursuit of a disease with significant consequence BACKGROUND The functional capacity of long-term survivors of submass 
    Output:
    
DISCUSSION Prompt initiation of anticoagulation reduces symptoms , rates of recurrent VTE and death but treatment must be balanced against the risk of major haemorrhage .