Safety of outpatient treatment in acute pulmonary embolism

INTRODUCTION

Data regarding outpatient treatment of pulmonary embolism (PE) is scarce. This study evaluates the safety of outpatient management of acute PE.

METHODS

This is a retrospective cohort study of consecutive patients presenting at the Ottawa Hospital with acute PE diagnosed between 1 January 2007 and 31 December 2008. PE was defined as an arterial filling defect on CTPA or a high probability V/Q scan. Patients were managed as outpatients if they were hemodynamically stable, did not require supplemental oxygenation and did not have contraindications to low-molecular-weight heparin therapy.

RESULTS

In this cohort of 473 patients with acute PE, 260 (55.0%) were treated as outpatients and 213 (45.0%) were admitted to the hospital. The majority of the patients were admitted because of severe comorbidities (45.5%) or hypoxia (22.1%). No outpatient died of fatal PE during the 3-month follow-up period. At the end of follow-up, the overall mortality was 5.0% (95% CI, 2.7-8.4%). The rates of recurrent venous thromboembolism (VTE) in outpatients were 0.4% (95% CI, 0.0-2.1%) and 3.8% (95% CI, 1.9-7.0%) within 14 days and 3 months, respectively. The rates of major bleeding episodes were 0% (95% CI, 0-1.4%) and 1.5% (95% CI, 0.4-3.9%) within 14 days and 3 months, respectively. Four (1.5%) outpatients were admitted to the hospital within 14 days.

CONCLUSIONS

A majority of patients with acute PE can be managed as outpatients with a low risk of mortality, recurrent VTE and major bleeding episodes.

Subsegmental pulmonary embolism diagnosed by computed tomography: incidence and clinical implications. A systematic review and meta-analysis of the management outcome studies

BACKGROUND

Multiple-detectors computed tomographic pulmonary angiography (CTPA) has a higher sensitivity for pulmonary embolism (PE) within the subsegmental pulmonary arteries as compared with single-detector CTPA. Multiple-detectors CTPA might increase the rate of subsegmental PE diagnosis. The clinical significance of subsegmental PE is unknown. We sought to summarize the proportion of subsegmental PE diagnosed with single- and multiple-detectors CTPA and assess the safety of diagnostic strategies based on single- or multiple-detectors CTPA to exclude PE.

PATIENTS AND METHODS

A systematic literature search strategy was conducted using MEDLINE, EMBASE and the Cochrane Register of Controlled Trials. We selected 22 articles (20 prospective cohort studies and two randomized controlled trials) that included patients with suspected PE who underwent a CTPA and reported the rate of subsegmental PE. Two reviewers independently extracted data onto standardized forms.

RESULTS

The rate of subsegmental PE diagnosis was 4.7% [95% confidence interval (CI): 2.5-7.6] and 9.4 (95% CI: 5.5-14.2) in patients that underwent a single- and multiple-detectors CTPA, respectively. The 3-month thromboembolic risks in patients with suspected PE and who were left untreated based on a diagnostic algorithm including a negative CTPA was 0.9% (95% CI: 0.4-1.4) and 1.1% (95% CI: 0.7-1.4) for single- and multiple-detectors CTPA, respectively.

CONCLUSION

Multiple-detectors CTPA seems to increase the proportion of patients diagnosed with subsegmental PE without lowering the 3-month risk of thromboembolism suggesting that subsegmental PE may not be clinically relevant.

A randomised clinical trial comparing minimally invasive surgery to conventional approach for endoprosthesis in elderly patients with hip fractures

BACKGROUND

In recent years, the concept of minimally invasive surgery has invaded the orthopaedic field and literature on the subject is spawning. Mini-incision surgery for total hip arthroplasty has been studied without a clear consensus on the efficacy, safety and advantage of that technique. To our knowledge, the efficacy and safety of mini-incisions in hip fracture surgery has not been studied in a randomised fashion.

METHODS

This study is a prospective clinically randomised trial whose primary objective was to demonstrate the safety and efficacy of a single posterior mini-incision approach compared to a standard posterior approach for endoprosthesis in acute femoral neck fractures. The mini-incision was defined as less than 8 cm. 25 patients in the mini-incision surgery (MIS) group and 31 patients in the standard incision group (STD) were available for analysis. The following validated disease-specific outcome instruments were used: the Lower Extremity Measurement (LEM) and the Time Up and Go (TUG). Secondary endpoints of pain, function, and quality of life were assessed by the components of the Harris Hip Score (HHS) and SF-36. Radiographic outcomes were also evaluated as well as the rates of all reported complications and adverse events during the 2 years follow-up.

RESULTS

There was no significant difference for operative time, blood losses, 72 h postoperative haemoglobin as well as the need for transfusion therapy between the two groups. Also, there was no difference between the groups for postoperative morphine use and pain evaluation with the Visual Analog Scale. The functional assessment using LEM and TUG did not demonstrate any statistically significant difference between mini- and standard incision. However, the HHS and the physical function component of the SF-36 were statistically better at 2 years in favour of the standard incision group.

CONCLUSION

Based on the results of the present study, we cannot recommend the use of a minimally invasive approach over a standard approach in the implantation of a cemented endoprosthesis.

L-arginine supplemented nondiluted blood cardioplegia: a clinical trial

AIM

L-arginine was shown to improve protection of the myocardium during coronary artery bypass graft (CABG) surgery. The objective of the present study was to determine the concentration of L-arginine to obtain the most effective protection of the myocardium during CABG surgery.

METHODS

Seventy-five patients undergoing CABG surgery were randomized in 3 groups. The first group (N.=25) was administered a placebo injection in the blood cardioplegic solution, the second group (N.=25) received an injection of 4 mmol/L of L-arginine and a third group (N.=25) an injection of 6 mmol/L of L-arginine in the blood cardioplegic solution. Blood samples from the ascending aorta and the coronary sinus catheter were collected before, immediately after and at 20 minutes after aortic cross-clamping. Total plasmatic nitrite and nitrate ratio and lactate release from the myocardium in the collected blood samples were measured.

RESULTS

Seventy-five patients averaging 62+/-7 years of age and undergoing 3.1+/-1 coronary bypass grafts during 41+/-17 minutes of aortic cross clamping time were recruited. Values of total plasmatic nitrite and nitrate ratio remains non-significant before and after aortic clamping and also between groups (P=0.9812 and 0.3573 respectively). Myocardial lactate release was statistically different before and after cross clamping (P=0.0002) and also between the 3 groups (P=0.0311).

CONCLUSION

Nondiluted blood cardioplegic solution supplemented with 4 mmol/L of L-arginine was associated with a significant decrease of myocardial lactate release after aortic cross-clamping and reperfusion during CABG surgery.

Differences in clinical presentation of pulmonary embolism in women and men

BACKGROUND

The risk of recurrence of pulmonary embolism (PE) is higher in men than in women. Differences in clinical presentation of deep vein thrombosis (DVT) have been reported between the two genders but comparative data on PE are lacking.

OBJECTIVES

To compare clinical characteristics between women and men with suspected and confirmed PE and their impact on clinical probability prediction scores and on diagnostic work-up of PE, and to assess whether differences at presentation could account for the increased recurrence rate in men.

METHODS

Combined data from three prospective cohort studies including a total of 3414 outpatients with suspected PE were analyzed retrospectively. Clinical characteristics, pretest probability of PE, diagnostic yield of non-invasive tests and VTE recurrence rate were compared between genders.

RESULTS

The overall prevalence of PE was similar among women and men (22.3% vs. 23.1%; P = 0.55). The clinical probability prediction scores (Geneva score and Wells score) performed equally well in both genders. A non-invasive diagnostic work-up was possible more often in men than in women. The proportion of PE-associated proximal DVT was higher in men than in women (43% vs. 33%; P = 0.009). VTE recurrence rate was also higher in men than women with PE (5.0% vs. 2.3%; P = 0.045).

CONCLUSION

In spite of some differences in the clinical presentation of PE between women and men, clinical probability prediction scores perform equally in both genders. A higher prevalence of PE-associated proximal DVT in men could possibly indicate greater severity of PE episodes and partly account for the higher VTE recurrence rate in men.

Prediction of the warfarin maintenance dose after completion of the 10 mg initiation nomogram: do we really need genotyping?

INTRODUCTION

Initiation of warfarin therapy is complicated by its narrow therapeutic index and inter-patient dose-effect variability. A '10-mg nomogram' warfarin initiation protocol permits safe therapeutic anticoagulation in outpatients started on warfarin. We aimed to develop a safe and effective warfarin maintenance dose prediction tool in these patients.

METHODS

Baseline potential predictor variables were collected on a retrospective cohort of outpatients initiated on warfarin for venous thromboembolism treatment. The primary outcome was the warfarin maintenance dose, defined as mean warfarin dose over the last 10 days of the first month of warfarin treatment. Univariate and multivariate analyses were performed to determine which baseline variables were warfarin maintenance dose predictors. An independent cohort of patients validated the derived warfarin maintenance dose prediction rule.

RESULTS

Patient's age and weight, cumulative dose of warfarin over the first week of induction and international normalized ratio (INR) on days 3, 5 and 8 were statistically significant predictors of the warfarin maintenance dose. Our final prediction rule reads: maintenance dose (in mg) = 2.5 + 10% of the first week cumulative dose - INR value at day 8 + 1.5 if INR was below 2.0 at day 5. In the validation cohort, the predicted dose was strongly correlated with the actual maintenance dose (r = 0.88, P < 0.0001). The mean difference between observed and predicted dose was not clinically significant: -0.1 +/- 1.1 mg.

CONCLUSION

In outpatients initiated on warfarin using a '10-mg nomogram', a simple prediction rule can accurately predict warfarin maintenance dose. Prospective studies employing the rule are indicated.

Dose escalation of low molecular weight heparin to manage recurrent venous thromboemblic events despite systemic anticoagulation in cancer patients

e20580

Background: Cancer patients with venous thromboembolism (VTE) are at high risk of recurrent VTE. The rate of recurrent VTE ranges from 9 to 17% despite therapy with low molecular weight heparins (LMWH) or vitamin K antagonists (VKA) respectively. To date, no published evidence is available to guide treatment of cancer patients with recurrent VTE. We sought to evaluate the benefit and risk of LMWH dose escalation in cancer patients with recurrent VTE. Methods: Retrospective cohort study was conducted in consecutive cancer outpatients referred for management of an objectively confirmed, symptomatic, recurrent VTE while receiving an anticoagulant. Patients were treated with either dose escalation of weight-adjusted LMWH in patients already anticoagulated with LMWH or initiation of a therapeutic dose LMWH in patients who were taking a VKA. All patients were followed for a minimum of 3 months after the index recurrent VTE. Results: Seventy cancer patients with a recurrent VTE despite ongoing anticoagulation were included. The median time between the initial VTE to the index recurrence was 3.5 months (range 0.3 to 193 months). At the time of the recurrence, 67% of patients were on LMWH, while 33% were on VKA. Following the treatment with either dose escalation or initiation of LMWH, a total of 6 patients (8.6%; 95% confidence interval (CI): 4.0% to 17.5%) had a second recurrent VTE during the three-month follow-up period, at an event rate of 9.9 per 100 patient-years (95% CI: 2.0 to 17.8). The median time between the index and second recurrent VTE was 1.9 months (range 0.6 to 3.0 months). One patient (1.4%; 95% CI: 0.3% to 7.7%), or 1.6 per 100 patient-years (95% CI: 0.0% to 4.8%) of follow-up, had a major bleeding event. The median time between the index recurrent VTE to death was 11.4 months (range 0 to 83.9 months). Conclusions: Patients with recurrent VTE have a poor prognosis. Escalating the dose of LMWH can be effective for treating cases that are resistant to standard, weight-adjusted doses of LMWH or a VKA.

[Table: see text]

Validation of a diagnostic approach to exclude recurrent venous thromboembolism

SUMMARY INTRODUCTION

The diagnosis of recurrent venous thromboembolism (VTE) is a challenge in clinical practice. Our objective was to evaluate the safety of a diagnostic strategy utilizing comparison of diagnostic test results with baseline imaging results to rule out suspected recurrent VTE.

METHODS

The REVERSE study was a prospective cohort study whose primary aim was to develop a clinical prediction rule for recurrent VTE. We included and followed patients who completed 5-7 months of anticoagulant therapy after a first unprovoked VTE. Suspected cases of recurrent VTE were assessed according to standardized diagnostic criteria based on comparison of diagnostic test results with those obtained at the time of anticoagulant treatment withdrawal.

RESULTS

Out of the 398 suspected events, a recurrent VTE was diagnosed in 106 cases (26.6%) and excluded in 292 cases. In 76 cases (19%), the diagnosis of recurrent VTE was excluded on the basis of the fact that no significant change on diagnostic imaging was detected when compared to baseline imaging. During the ensuing 3 months, six patients received anticoagulant therapy after recurrent VTE was excluded, and two were lost to follow-up. Eight of 284 remaining patients in whom recurrent VTE had been excluded, who were not treated and who were not lost to follow-up were diagnosed with subsequent VTE (3-month risk, 2.8%; 95% confidence interval, 1.4-5.5%). Six of these eight patients with subsequent recurrent VTE had a known superficial or distal thrombosis at the time of initial suspected recurrent VTE.

CONCLUSION

A diagnostic strategy comparing diagnostic test results obtained at the time of the suspected recurrent event with those obtained at baseline can safely and effectively rule out recurrent VTE in a significant proportion of patients. Registered at http://www.clinicaltrials.gov identifier: NCT00261014.

Dose escalation of low molecular weight heparin to manage recurrent venous thromboembolic events despite systemic anticoagulation in cancer patients

SUMMARY BACKGROUND

Cancer patients with venous thromboembolism (VTE) are at high risk of recurrent VTE despite standard anticoagulation. To date, very little published literature is available to guide the treatment of cancer patients with recurrent VTE.

OBJECTIVES

To evaluate the benefit and risk of low molecular weight heparin (LMWH) dose escalation in cancer patients with recurrent VTE.

PATIENTS AND METHODS

This was a retrospective cohort study of consecutive cancer outpatients referred for management of a symptomatic, recurrent VTE while receiving an anticoagulant. Confirmed episodes of recurrent VTE were treated with either dose escalation of LMWH in patients already anticoagulated with LMWH, or initiation of therapeutic dose LMWH in patients who were taking a vitamin K antagonist (VKA). All patients were followed for a minimum of 3 months after the index recurrent VTE unless they died during this period.

RESULTS

Seventy cancer patients with a recurrent VTE despite ongoing anticoagulation were included. At the time of the recurrence, 67% of patients were receiving LMWH, and 33% were receiving a VKA. A total of six patients [8.6%; 95% confidence interval (CI) 4.0-17.5%] had a second recurrent VTE during the 3-month follow-up period, at an event rate of 9.9 per 100 patient-years (95% CI 2.0-17.8%). Three patients (4.3%; 95% CI 1.5-11.9%), or 4.8 per 100 patient-years (95% CI 0.0-10.3%) of follow-up, had bleeding complications. The median time between the index recurrent VTE to death was 11.4 months (range, 0-83.9 months).

CONCLUSIONS

Cancer patients with recurrent VTE have a short median survival. Escalating the dose of LMWH can be effective for treating cases that are resistant to standard, weight-adjusted doses of LMWH or a VKA.

CarboMedics Mitroflow pericardial aortic bioprosthesis - performance in patients aged 60 years and older after 15 years

BACKGROUND

The purpose of this study was to carry out a current assessment of the Mitroflow pericardial bioprosthesis (model 11) according to the durability of the prosthesis after 15 years in patients aged 60 years or older.

METHODS

This bioprosthesis was implanted in 161 patients (mean age 69.5 +/- 6.3 years; range 60 - 94 years) undergoing aortic valve replacement (AVR) between 1982 and 1992. There were 84 patients aged 60 - 69 years (mean 64.5 +/- 3.1years) and 77 patients aged 70 years or older (mean 74.8 +/- 4.3 years). Of the total population, concomitant procedures were performed in 63 patients (39.1 %); of these, coronary artery bypass grafting was performed in 39 (24.2 %).

RESULTS

Early mortality was 4.8 % (4 patients) in the 60 - 69 year age group and 10.4 % (8) in patients aged 70 years or older ( P = 0.290). Late mortality was 4.5 %/patient-year (35) for those aged 60 - 69 years and 8.1 %/patient-year (49) for those aged 70 years or older ( P = 0.007). Patient survival at 15 years of patients aged 60 - 69 years was 47.6 +/- 6.3 % and of patients aged 70 years or older was 20.9 +/- 5.4 % ( P = 0.003) ( ). Freedom from valve-related mortality for patients in the 60 - 69 year age group was 92.1 +/- 3.5 % at 15 years (0.6 %/patient-year [5]), and in the patient group aged 70 years or older it was 84.4 +/- 5.3 % (1.3 %/patient-year [8]; P = 0.194). Freedom from reoperation for patients in the 60 - 69 year age group was 73.9 +/- 5.0 % (2.6 %/patient-year [20]), and for patients aged 70 years or older it was 91.4 +/- 3.4 % (1.0 %/patient-year [6]; P = 0.029). The structural valve deterioration (SVD) rate for patients in the 60 - 69 year age group was 2.4 %/patient-year (19), and for patients aged 70 years or older it was 1.0 %/patient-year (6) ( P = 0.041). Actuarial freedom from structural valve deterioration at 15 years for patients aged 60 - 69 years was 62.0 +/- 7.3 %, and 80.8 +/- 7.9 % for patients aged 70 years and older ( P = 0.049) (actual freedom 73.9 +/- 5.2 % and 91.4 +/- 3.4 %, respectively).

CONCLUSIONS

The Mitroflow pericardial bioprosthesis can still be recommended for aortic valve replacement in patients 70 years and older.

Incidence of symptomatic venous thromboembolism following hematopoietic stem cell transplantation

BACKGROUND

The incidence of symptomatic venous thromboembolism (VTE) following hematopoietic stem cell transplantation (HSCT) is not well described, particularly with increased use of ambulatory care in the transplant setting.

METHODS

A retrospective analysis involving 589 patients (382 autologous HSCT, 207 allogeneic HSCT) undergoing transplantation between 2000 and 2005 in a single Canadian institution was undertaken to identify the incidence of proximal deep vein thrombosis (DVT) or pulmonary embolism (PE) in HSCT patients.

RESULTS

The total 1-year incidence of symptomatic VTE was 3.7% [95% confidence interval (CI) 2.5-5.6]. Among the HSCT patients, 7/589 (1.2%, 95% CI 0.6-2.4) developed symptomatic non-catheter-related VTE following HSCT (four PE and three DVT). All VTE events occurred after hematopoietic engraftment. Patients undergoing autologous HSCT did not receive thromboprophylaxis, whereas most patients undergoing allogeneic HSCT (79.7%) received enoxaparin 20 mg daily for the prevention of veno-occlusive disease of the liver, starting 6 +/- 3 days before transplantation for a mean of 22 +/- 14 days.

CONCLUSION

HSCT patients have a high incidence of VTE. Thromboprophylaxis should potentially be considered in these patients. However, future studies assessing the risk and benefits of thromboprophylaxis are needed in this specific population.

D-dimer testing is useful to exclude deep vein thrombosis in elderly outpatients

BACKGROUND

Deep vein thrombosis (DVT) can be safely and reliably excluded in patients with a low clinical probability and a negative D-dimer result but the accuracy and utility of such a strategy is unclear in elderly patients.

OBJECTIVES

We sought to compare the performance of the Wells pretest probability (PTP) model and D-dimer testing between patients of different age groups and to examine the utility of the two PTP model classification schemes (low/moderate/high vs. unlikely/likely) in excluding DVT in elderly outpatients.

PATIENTS/METHODS

Pooled analysis of databases from three prospective diagnostic studies evaluating consecutive outpatients with suspected DVT.

RESULTS

A total of 2696 patients were evaluated. DVT was diagnosed in 400 (15%) patients overall and in 50 out of 325 (15.5%) patients > or = 60 years old. The PTP distribution and the prevalence of DVT in each PTP category were similar among the different age groups. The negative predictive values of a low or unlikely PTP score in combination with a negative D-dimer result were 99% for all groups. A negative D-dimer in combination with a low or unlikely PTP excluded 21.7% and 31% of patients > or = 80 years old, respectively.

CONCLUSIONS

The combination of a low or unlikely PTP with a negative D-dimer result can effectively and safely exclude DVT in a significant proportion of elderly outpatients. However, this clinical prediction rule needs to be prospectively validated with different D-dimer assays in this specific population.

Protective effect of pyridoxal-5-phosphate (MC-1) on perioperative myocardial infarction is independent of aortic cross clamp time: results from the MEND-CABG trial

AIM

Aortic cross-clamp time remains a significant marker of mortality and morbidity after coronary artery bypass graft (CABG) surgery. Pyridoxal-5-phosphate (MC-1), blocking purinergic receptors and intracellular influx of calcium, was shown to decrease the incidence of perioperative myocardial infarction in the prospective, randomized, double-blinded MC-1 to Eliminate Necrosis and Damage in CABG (MEND-CABG) clinical trial.

METHODS

We studied the relationship between treatment with MC-1 and aortic cross-clamping relative to the incidence of cardiovascular (CV) death and myocardial infarction (MI) in the trial that enrolled 901 high-risk patients undergoing CABG with cardiopulmonary bypass. Patients were randomized to receive either placebo, MC-1 250 mg/day or MC-1 750 mg/day starting 3-10 h before CABG and continued for 30 days after surgery. Serial creatine kinase-myocardial band (CK-MB) determinations, ECGs and clinical evaluations were performed.

RESULTS

Cross-clamping time increased the event rate of death and MI with an odds ratio (95% confidence interval) of 1.67 (1.17-2.37, P=0.0044). Treatment with MC-1 decreased the rate of events (P=0.0073) with odds ratios of 0.52 (0.31-0.88 for MC-1 250 mg/day versus placebo) and 0.48 (0.29-0.82 for MC-1 750 mg/day versus placebo). There was no interaction between cross-clamp time and treatment (P=0.61) on the occurrence of the combined endpoint.

CONCLUSION

MC-1 decreased the incidence of CV death and MI (CK-MB >or=100 ng/mL) during the first 90 days after CABG in the MEND-CABG trial. Although longer aortic clamping time increased the risk of cardiovascular events, the protective effect of MC-1 was independent of ischemic time during CABG.

3. Interactive online software documenting and corroborating exposure to CanMEDS Roles

Residents are exposed to various situations contributing to the development of their CanMEDS roles. Exposure to different clinical scenarios and teaching situations contributing to the development of the CanMEDS roles could be identified, documented by residents and corroborated by staff supervisors retrospectively. A rapid and thorough method to assess this exposure is not available and could help to monitor a programs strengths and weaknesses. Daily activities developing specific CanMEDS roles where identified initially by the program director and residents. An internet based automatic survey generator (residentevaluation.com) was built to interrogate residents on a weekly basis on their exposure these clinical activities, linked to the seven CanMEDS roles. The surveys where automatically directed to supervisors for corroboration and comments. Periodic and annual reports where sent to the program director. The study group was composed of the Université de Montréal cardiac surgical trainees (n=6). Weekly surveys were sent from July 2006 to March 2007 (Ongoing). Participation rose from 42% to 79% in trainees and was 70% among supervisors. Time to fill the weekly survey was less than 1 minute for trainees and supervisors. The majority of residents documented development of all seven CanMEDS roles on a weekly basis. The trainees were exposed on a weekly basis to a reflection on the development of their CanMEDS competences. Cardiac surgical trainees at Université de Montréal are exposed and develop their CanMEDS roles over their regular training. The residentevaluation.com program allows a rapid weekly assessment and documentation of exposure to CanMEDS roles. The tool provides periodic and annual reports for program directors to quantify this exposure and adjust the program objectives. This software could be used in other programs to assess its efficiency in different cohorts. Frank, JR, ed. 2005. The CanMEDS 2005 physician competency framework. Better standards. Better physicians. Better care. Ottawa: The Royal College of Physicians and Surgeons of Canada Frank JR, Jabbour M, Fréchette D, Marks M, Valk N, Bourgeois G, eds. Report of the CanMEDS Phase IV Working Groups. Ottawa: The Royal College of Physicians and Surgeons of Canada. March, 2005.

Accuracy and usefulness of a clinical prediction rule and D-dimer testing in excluding deep vein thrombosis (DVT) in cancer patients

19522

Background: Cancer patients frequently present with thrombotic complications and rapid, accurate diagnostic testing would reduce morbidity and mortality. Although the combination of a low clinical probability using clinical prediction rules (e.g. Well’s Score) and a negative D-dimer result have proven to be safe and reliable in ruling out DVT in the general population, the accuracy of such a strategy is less certain in cancer patients. Because cancer patients often have alternative reasons for leg swelling and pain, and because malignancy and chemotherapy can render the D-dimer test positive in the absence of DVT, we hypothesize that the Well’s Score and D-dimer testing are potentially less accurate and less useful in excluding DVT in patients with active cancer. Methods: We performed a retrospective analysis of 2 prospective studies to compare the diagnostic test characteristics of the Well’s Score and D-dimer testing between patients with and without cancer presenting with suspected DVT. Results: A total of 1630 patients were studied; 107 had cancer. DVT was confirmed in 39.3% of patients with and 13.7% of patients without cancer. In both patient groups, the proportions of patients with DVT were significantly different among the high-, moderate- and low-probability groups according to the Well’s score (P<0.001). However, significantly fewer cancer patients (19.6%) had a low-probability score compared to patients without cancer (47.5%) (P<0.001). Similarly, 36.4% of cancer vs. 60.4% of noncancer patients had a negative D-dimer result (P<0.001). In cancer patients, a low probability score alone had a sensitivity of 95.2% (95%CI 82.6%-99.2%) and a specificity of 29.2% (95% CI 18.9%-42.0%). In combination with D-dimer testing, the sensitivity improved to 100% (95%CI 31.0%-100%) but the specificity was reduced to 26.4% (95%CI 13.5%-44.7%). In contrast, the specificity in patients without cancer was preserved at 53.9% (95%CI 50.4%-57.3%). Conclusion: DVT can be ruled out in cancer patients with a low clinical probability of DVT and a negative D-dimer result. However, the low specificity of these tests excludes very few patients and thereby limits their clinical usefulness.

No significant financial relationships to disclose.