Mortality in Pulmonary Embolism According to Risk Category at Presentation in Emergency Department: Impact of Cardiac Arrest

In this investigation we explore whether assessment of the risk of mortality can be refined by stratifying high-risk patients with pulmonary embolism (PE) according to whether they had cardiac arrest. We stratified high-risk patients according to whether they had shock but no cardiac arrest, or cardiac arrest diagnosed in the emergency department (ED). This was a retrospective cohort study based on administrative data from the Nationwide Emergency Department Sample (NEDS), 2016. Included patients were 274,227 who were admitted to the same hospital as the ED or died in the ED. This was 77% of 354,616 patients with pulmonary embolism seen in the ED in 2016. Patients were identified based on International Classification of Diseases, 10th Edition, Clinical Modification (ICD-10-CM) Codes. High-risk with no cardiac arrest were 4,317 of 274,227 (1.6%) and high-risk with cardiac arrest were 1,027 of 274,227 (0.4%). Mortality of high-risk patients who did not have cardiac arrest was 1,753 of 4,317 (41%). Mortality of high-risk patients who had cardiac arrest was 754 of 1027 (74%). Mortality increased with age in high-risk patients who did not have cardiac arrest, but mortality was not age-related in high-risk patients with cardiac arrest. In conclusion, high-risk patients with PE are a heterogeneous group and stratification according to whether they had cardiac arrest refines risk assessment.

Hospitalizations for High-Risk Pulmonary Embolism

BACKGROUND

The incidence of pulmonary embolism has been increasing. It has been suggested that this may reflect overdiagnosis due to widespread use of computed tomographic pulmonary angiography. The purpose of the present investigation is to further evaluate whether the increasing incidence of pulmonary embolism represents overdiagnosis.

METHODS

This was a retrospective cohort study based on administrative data from the National (Nationwide) Inpatient Sample 1999-2014. International Classification of Diseases, Ninth Revision, Clinical Modification codes were used. The population of the United States according to year was determined from the Centers for Disease Control and Prevention.

RESULTS

The incidence of pulmonary embolism increased from 65/100,000 population in 1999 to 137/100,000 population in 2014 (P < .0001). High-risk pulmonary embolism increased from 2.2/100,000 population to 9.9/100,000 population (P < .0001). The incidence of primary pulmonary embolism increased from 40/100,000 population in 1999 to 73/100,000 population in 2014 (P < .0001). High-risk pulmonary embolism in patients with a primary diagnosis of pulmonary embolism increased from 0.8/100,000 population in 1999 to 2.3/100,000 population in 2014 (P < .0001). Among patients with pulmonary embolism, the incidence of high-risk pulmonary embolism increased from 1999-2014 (P = .0025). In-hospital all-cause mortality in high-risk patients was 102,402 of 195,909 (52.2%).

CONCLUSIONS

The incidence of high-risk pulmonary embolism has increased concordantly with the increasing incidence of all pulmonary embolism. Increasing proportions of patients with potentially lethal pulmonary embolism are being diagnosed.

Site of Deep Venous Thrombosis and Age in the Selection of Patients in the Emergency Department for Hospitalization Versus Home Treatment

Despite apparent advantages of home treatment of deep venous thrombosis (DVT) based upon results of randomized controlled trials, physicians maintain a conservative approach, and a large proportion of patients with DVT are hospitalized. In the present investigation we assess whether selection of patients for hospitalization for acute DVT was related to the site of the DVT or to age. This was a retrospective cohort study based on administrative data from the Nationwide Emergency Department Sample, 2016. Patients were identified by International Classification of Diseases-10-Clinical Modification codes. Most, 87,436 of 133,414 (66%), had proximal DVT. A minority of patients with isolated distal DVT were hospitalized, 10,621 of 37,592 (28%). However, hospitalization was selected for 47,459 of 87,436 (54%) with proximal DVT; 4,867 of 7,599 (64%) with pelvic vein DVT; and 611 of 788 (78%) with DVT involving the inferior vena cava. Hospitalization for patients with distal DVT, proximal DVT, and pelvic vein DVT was age-dependent. In conclusion, both the site of acute DVT and age were factors affecting the clinical decision of emergency department physicians to select patients for hospital treatment.

Effects of Thrombolytic Therapy in Low-Risk Patients With Pulmonary Embolism

We performed this investigation to determine the effects on mortality of thrombolytic therapy in low-risk patients with pulmonary embolism (PE). This was a retrospective cohort study based on administrative data from the Nationwide Inpatient Sample, 2016 and 2017. Patients with a primary (first-listed) diagnosis of acute PE who were not in shock and not on a ventilator who did not have acute cor pulmonale were defined as low-risk. Patients were identified by International Classification of Diseases-10-Clinical Modification Codes. Mortality was assessed according to treatment with catheter-directed thrombolysis, intravenous thrombolytic therapy, or anticoagulants alone. Mortality with inferior vena cava (IVC) filters was also assessed. Mortality was lowest in low-risk patients treated with anticoagulants alone, 6,765 of 331,430 (2.0%). Mortality was somewhat higher with catheter-directed thrombolysis, 195 of 6915 (2.8%; p <0.0001), and highest with intravenous thrombolysis 510 of 5,200 (9.8%; p <0.0001). Matched patients showed similar results. IVC filters did not reduce mortality in patients treated with anticoagulants alone. Mortality was only 0.5% higher in patients treated with anticoagulants who had saddle PE than in patients with nonsaddle PE, 450 of 17,935 (2.5%) versus 6,315 of 313,495 (2.0%; p <0.0001). However, a larger proportion of low-risk patients with saddle PE received catheter-directed thrombolysis than patients who had nonsaddle PE, 2,330 of 21,760 (11%) versus 4,585 of 321,785 (1.4%; p <0.0001). Similarly, a larger proportion of patients with saddle PE received intravenous thrombolytic therapy than patients with nonsaddle PE, 1,495 of 21,760 (6.9%) versus 3,705 of 321,785 (1.2%; p <0.0001). In conclusion, low-risk patients with PE did not have lower mortality with catheter-directed thrombolysis or intravenous thrombolytic therapy than with anticoagulants alone, and IVC filters did not reduce mortality with anticoagulants alone.

Catheter-Directed Thrombolysis in Submassive Pulmonary Embolism and Acute Cor Pulmonale

Treatment of submassive (intermediate-risk) pulmonary embolism (PE), defined as hemodynamically stable with right ventricular (RV) dysfunction, showed lower in-hospital all-cause mortality with intravenous thrombolytic therapy than with anticoagulants, but at an increased risk of major bleeding. The present investigation was performed to test whether catheter-directed thrombolysis reduces mortality without increasing bleeding in submassive PE. This was a retrospective cohort study based on administrative data from the Nationwide Inpatient Sample. In 2016, 13,130 patients were hospitalized with PE and acute cor pulmonale, were stable, and treated with catheter-directed thrombolysis in 1,500 (11%) or anticoagulants alone in 11,630 (89%). Mortality was lower with catheter-directed thrombolysis than with anticoagulants in unmatched patients, 35 of 1,500 (2.3%) compared with 755 of 11,630 (6.5%; p <0.0001) and in matched patients, 30 of 1,260 (2.4%) compared with 440 of 6,910 (6.4%; p <0.0001). Time-dependent analysis showed catheter-directed thrombolysis reduced mortality if administered within the first 3 days. Patients with saddle PE treated with anticoagulants had lower mortality than non-saddle PE, 75 of 1,730 (4.3%) compared with 680 of 9,900 (6.9%; p < 0.0001) in unmatched patients and 45 of 1,305 (3.4%) compared with 395 of 5,605 (7.0%; p < 0.0001) in matched patients. Mortality was not lower with inferior vena cava filters either in those who received catheter-directed thrombolysis or those treated with anticoagulants. There were no fatal or nonfatal adverse events associated with catheter-directed thrombolysis. In conclusion, patients with submassive PE appear to have lower in-hospital all-cause mortality with catheter-directed thrombolysis administered within 3 days than with anticoagulants, and risks are low.

Adjunctive Therapy and Mortality in Patients With Unstable Pulmonary Embolism

Mortality with adjunctive therapy in patients with unstable pulmonary embolism, defined as those in shock or on ventilator support, is sparsely studied and requires further investigation. This was a retrospective cohort study based on administrative data from the Nationwide Inpatient Sample, 2016. In-hospital all-cause mortality in unstable patients with acute pulmonary embolism was assessed according to treatment. Patients were identified by International Classification of Diseases-10-Clinical Modification Codes. Most unstable patients, 85%, received only anticoagulants. Their mortality was 3,080 of 6,635 (46%) without an inferior vena cava (IVC) filter, and mortality was much less with an IVC filter, 285 of 1,185 (24%) (p <0.0001). Mortality with catheter-directed thrombolysis alone, 70 of 235 (30%), did not differ significantly from mortality with anticoagulants plus an IVC filter, p = 0.07, although a trend favored the latter. Intravenous thrombolytic therapy without an IVC filter showed a mortality of 295 of 695 (42%) which tended to be lower than mortality with anticoagulants alone (p = 0.06). The addition of an IVC filter to intravenous thrombolytic therapy resulted in a mortality of 20 of 165 (12%), which was the lowest mortality with any combination of adjunctive treatments. Intravenous thrombolytic therapy, however, was associated with more adverse effects of therapy than catheter-directed thrombolysis or anticoagulants.

Effect on Mortality With Inferior Vena Cava Filters in Patients Undergoing Pulmonary Embolectomy

In the absence of a randomized controlled trial, it is important to obtain as much evidence as possible by other methods on whether inferior vena cava (IVC) filters reduce mortality in patients who undergo pulmonary embolectomy. Therefore, this retrospective cohort study based data from the National Inpatient Sample 2009 to 2014 was undertaken. We assessed in-hospital all-cause mortality in stable and unstable (in shock or on ventilator support) patients with acute pulmonary embolism who underwent pulmonary embolectomy. International Classification of Diseases-9-Clinical Modification (ICD-9-CM) codes were used to identify patients. Co-morbidities were assessed by the updated Charlson co-morbidity index. A time-dependent analysis was performed to control for immortal time bias. In stable patients who underwent pulmonary embolectomy, mortality with an IVC filter was 50 of 1,212 (4.1%) compared with 202 of 755 (27%) with no IVC filter (p <0.0001). In unstable patients, mortality with an IVC filter was 108 of 598 (18%) compared with 179 of 358 (50%) with no IVC filter (p <0.0001). Mortality was reduced with IVC filters only if the filters were inserted in the first 4 or 5 days. Co-morbid conditions and immortal time bias could not explain these results. We conclude that both stable and unstable patients who underwent pulmonary embolectomy had a lower mortality with IVC filters if inserted in the first 4 or 5 days.

Effectiveness of Inferior Vena Cava Filters in Patients With Stable and Unstable Pulmonary Embolism and Trends in Their Use

BACKGROUND

Trends in the use of inferior vena cava (IVC) filters in patients with pulmonary embolism (PE) who are stratified according to whether they are stable or unstable (in shock or ventilator dependent) may show where improvements of management could be made according to the best evidence that we now have.

METHODS

This was a retrospective cohort study based on administrative data, 1999-2014, from the National (Nationwide) Inpatient Sample.

RESULTS

In-hospital all-cause mortality in unstable patients who received an IVC filter was lower in each year of investigation and in all age groups. Mortality from 1999 to 2014 was 10,140 of 35,230 (28.8%) with an IVC filter compared with 54,018 of 116,642 (46.3%) without a filter (P <0.0001). In stable patients from 1999 to 2014, mortality with an IVC filter was 31,909 of 546,858 (5.8%) with an IVC filter compared with 220,443 of 3,367,783 (6.5%) without a filter (P <0.0001). In patients ages > 80 years, mortality in stable patients with an IVC filter was 7,438 of 114,457 (6.5%) with an IVC filter compared with 64,113 of 567,348 (11.3%) without an IVC filter (P <0.0001). The number of stable patients who received an IVC filter decreased from 2010 to 2014, but even in those years the largest number of IVC filters was inserted in stable patients, 194,502 of 212,611 (91.5%).

CONCLUSIONS

Mortality is markedly reduced in unstable patients who receive an IVC filter. Despite this, the proportion of unstable patients who receive an IVC filter is decreasing. The largest number of IVC filters continues to be inserted in stable patients, although there is no evidence of a clinically meaningful reduced mortality with IVC filters in stable patients unless age >80 years.

Continuing Use of Inferior Vena Cava Filters Despite Data and Recommendations Against Their Use in Patients With Deep Venous Thrombosis

The purpose of the present investigation is to determine the response to the evidence and recommendations against the use of inferior vena cava (IVC) filters in patients with deep venous thrombosis (DVT). This was a retrospective cohort study based on administrative data from the National Hospital Discharge Survey 1979 to 2006 and from the National (Nationwide) Inpatient Sample 2007 to 2014. The number of IVC filters inserted in patients with lone DVT peaked in 2009 and then decreased from 2009 to 2014. The proportion of patients with lone DVT who received an IVC filter peaked in 2010 and then decreased from 2010 to 2014. Both the number of IVC filters inserted yearly and the proportion of patients who received an IVC filter remained higher than in 1998 when a randomized controlled trial showed no reduced mortality with permanent IVC filters in patients with DVT. In conclusion, large numbers of patients with lone DVT continue to receive IVC filters despite a randomized controlled trial that showed no reduced mortality with IVC filters in patients with DVT and despite clinical guideline recommendations against the use of IVC filters in such patients.

Usefulness of Inferior Vena Cava Filters in Stable Patients with Acute Pulmonary Embolism

Retrospective cohort studies using administrative data from national databases or a registry suggest that there are subcategories of stable patients with acute pulmonary embolism who would show a reduced mortality with an inferior vena cava (IVC) filter in addition to anticoagulants. These subcategories are those who underwent pulmonary embolectomy, receiving thrombolytic therapy, suffering recurrent pulmonary embolism while on treatment, hospitalized with solid malignant tumors if aged >60 years, hospitalized with chronic obstructive pulmonary disease (COPD) if aged >50 years, and very elderly (aged >80 years). The following is a review of these studies. It is important to be circumspect in inferring a lower mortality with IVC filters based on comparative effectiveness research that uses national observational data. On the other hand, the likelihood of a randomized controlled trial in any of these subcategories of stable patients is remote. Whether patients are better served by inserting an IVC filter on the basis of retrospective cohort studies, or by withholding IVC filters until a randomized controlled trial can be obtained is a matter for consideration.

Inferior Vena Cava Filters in Patients with Recurrent Pulmonary Embolism

BACKGROUND

There are sparse data to support the recommendation for inferior vena cava (IVC) filters in patients with recurrent pulmonary embolism while on anticoagulant therapy.

METHODS

This was a retrospective cohort study of administrative data from the Premier Healthcare Database, 2009-2014. All-cause mortality according to the use of IVC filters was evaluated in patients who suffered a recurrent pulmonary embolism within 3 months of an index pulmonary embolism. Patients were identified by International Classification of Disease, 9th Clinical Modification codes. A time-dependent analysis controlled for immortal time bias.

RESULTS

An IVC filter was inserted in 603 of 814 (74.1%) of patients hospitalized for recurrent pulmonary embolism within 3 months of an index pulmonary embolism. Mortality with an IVC filter was 18 of 603 (3.0%) vs 83 of 211 (39.3%) (P < .0001) without a filter. Among patients with recurrent pulmonary embolism who were stable and did not receive thrombolytic therapy or undergo pulmonary embolectomy, mortality with an IVC filter was 15 of 572 (2.6%) vs 72 of 169 (42.6%) (P < .0001) without a filter.

CONCLUSION

In the United States, usual practice was to insert an IVC filter in patients with early recurrent pulmonary embolism. Mortality was lower in those who received an IVC filter. Even stable patients with early recurrent pulmonary embolism showed a decreased mortality with IVC filters, even though in other circumstances, IVC filters do not reduce mortality in stable patients. Additional cohort studies would be useful in the absence of a randomized controlled trial.

Importance of Early Insertion of Inferior Vena Cava Filters in Unstable Patients with Acute Pulmonary Embolism

BACKGROUND

Immortal time bias is a possible confounding factor in cohort studies. In this investigation, we assessed mortality with inferior vena cava (IVC) filters in unstable patients with pulmonary embolism using a design to control for immortal time bias.

METHODS

Data were from the Premier Healthcare Database, 2010-2014. International Classification of Diseases-Ninth Revision-Clinical Modification codes were used. Unstable patients with pulmonary embolism and an admitting diagnosis of pulmonary embolism, as well as a primary diagnosis of pulmonary embolism, were included. A time-dependent analysis was used according to the day of insertion of the IVC filter to control for immortal time bias.

RESULTS

Among all unstable patients, irrespective of the use of thrombolytic therapy, in-hospital all-cause mortality was 35 of 180 (19.4%) in those who received an IVC filter vs 122 of 299 (40.8%) with no filter (P < .0001). Mortality was lower in patients in whom the IVC filter was inserted on days 1 or 2 (on day 1, 21.4% compared with 40.8%, P = .017, and on day 2, 14.8% compared with 29.2%, P = .023), but it was not lower in those in whom the filter was inserted on subsequent days.

CONCLUSIONS

Mortality in unstable patients with pulmonary embolism appeared to be reduced with IVC filters only when the filter was inserted on the first or second day of admission. The design used for these analyses controlled for immortal time bias as a cause of the lower mortality with IVC filters.

CT Pulmonary Angiography in Young Women

The purpose was to determine whether young women in the emergency department who received computed tomographic (CT) pulmonary angiograms were evaluated to receive lower dose imaging or no imaging, recognizing that the risks of radiation are particularly high in young women. This was a retrospective cohort investigation of women aged 18 to 29 years seen for suspected acute pulmonary embolism in emergency departments of 5 regional hospitals from May 1, 2015 to April 30, 2016. Computed tomographic (CT) pulmonary angiograms were obtained in 379 young women. Pulmonary embolism was diagnosed by CT angiography in 2.1%. A Wells probability score could be calculated in 11.9%. D-dimer was obtained in 46.2% and a chest radiograph was obtained in 41.7%. Among patients with a normal chest radiograph, 3.9% had a lung scan. Venous ultrasound of the lower extremities was obtained in 1.8%. Each had an elevated D-dimer. Among the young women who received CT angiograms, 53 were pregnant. In 17.0% of pregnant women, a Wells clinical probability score could be calculated from the medical record. D-dimer in pregnant women was obtained in 30.2%, chest radiograph in 22.6%, lung scan in 11.3%, and venous ultrasound of the lower extremities in none. In conclusion, young women and pregnant women often received CT pulmonary angiograms for suspected acute pulmonary embolism without an objective clinical assessment, measurement of D-dimer, lung scintiscan, or venous ultrasound, which may have eliminated the need for CT pulmonary angiography in many instances.

Inferior Vena Cava Filters in Patients with Acute Pulmonary Embolism and Cancer

BACKGROUND

Administrative data have shown a lower mortality in hospitalized patients with pulmonary embolism and cancer who receive a vena cava filter. In the absence of a randomized controlled trial of vena cava filters in such patients, further investigation is necessary. Therefore, we performed this investigation using administrative data from a different database than used previously, and we investigate patients hospitalized in more recent years.

METHODS

We analyzed administrative data from the Premier Healthcare Database, 2010-2014, in patients hospitalized with pulmonary embolism and solid malignant tumors. Patients were identified on the basis of International Classification of Disease, Ninth Revision, Clinical Modification codes.

RESULTS

Patients aged >60 years had a lower in-hospital all-cause mortality with vena cava filters than those who did not have filters, 346 of 4648 (7.4%) compared with 2216 of 19,847 (11.2%) (P < .0001) (relative risk 0.67). Among patients aged >60 years who received an inferior vena cava, all-cause mortality within 3 months was 704 of 4648 (15.1%), compared with 3444 of 19,847 (17.4%) among those who did not receive a filter (P < .0001) (relative risk 0.86).

CONCLUSION

Elderly patients with pulmonary embolism and cancer may be a special population in whom inferior vena cava filters reduce in-hospital and 3-month all-cause mortality. Further investigation is needed, particularly in younger patients.

Prophylactic inferior vena cava filters in patients with fractures of the pelvis or long bones

BACKGROUND

Which patients with fractures, if any, have a lower mortality with prophylactic inferior vena cava filters has yet to be established. The purpose of this investigation is to determine if patients with low-risk fractures might benefit from a prophylactic inferior vena cava filter.

METHODS

Administrative data was analyzed from the National (Nationwide) Inpatient Sample using ICD-9-CM codes. Included patients were aged 18 years or older with a primary diagnosis of non-complex fracture of the pelvis, or fracture of the femuralone, or fracture of the tibia and/or fibula.

RESULTS

From 2003-2012, 1,479,039 patients were hospitalized with low-risk fracture. The vast majority of patients with fracture, 1,461,378 of 1,479,039 (98.8%) did not receive an inferior vena cava filter. Among those who did not receive a filter, 1,446,489 of 1,461,378 (99.0%) did not develop deep venous thrombosis or pulmonary embolism. Pulmonary embolism without a filter occurred in 7207 of 1,461,378 (0.5%) and deep venous thrombosis occurred in 7682 of 1,461,378 (0.5%). Total in-hospital all-cause mortality in those who did not receive a filter was 15,683 of 1,461,378 (1.1%). An inferior vena cava filter was inserted in 17,661 of 1,479,039 (1.2%) of patients with fractures. Most of those who received an inferior vena cava filter, 12,025 of 17,661 (68.1%) did not develop pulmonary embolism or deep venous thrombosis. Total in-hospital all-cause mortality in all patients with an inferior vena cava filter was 516 of 17,661 (2.9%).

CONCLUSION

The evidence is against the use of a prophylactic inferior cava vena filter in patients with a non-complex pelvic fracture or single fracture of the femur or fracture of the tibia and/or fibula.

Inferior Vena Cava Filters in Stable Patients with Acute Pulmonary Embolism Who Receive Thrombolytic Therapy

BACKGROUND

There is a need for further analyses of subgroups of patients with pulmonary embolism who might benefit from vena cava filters. In the present investigation, we analyze mortality with vena cava filters in the subgroup of stable patients with pulmonary embolism who received thrombolytic therapy. We use a different database than used previously, and we analyze data in more recent years.

METHODS

Administrative data were analyzed from the Premier Healthcare Database, 2010-2014, in hospitalized stable patients with pulmonary embolism who received thrombolytic therapy and may or may not have received a vena cava filter. Patients were identified on the basis of International Classification of Disease, Ninth Revision, Clinical Modification codes.

RESULTS

In-hospital all-cause mortality in stable patients who received a vena cava filter in addition to thrombolytic therapy was 139 of 2660 (5.2%), compared with 697 of 4332 (16.1%) who did not receive a filter (P < .0001) (relative risk .32). Mortality was lower with a filter every decade of age ≥ 31 years.

CONCLUSION

Among stable patients with acute pulmonary embolism who receive thrombolytic therapy, irrespective of the reason, the additional use of an inferior vena cava filter results in a lower in-hospital mortality.

Vena cava filters in hospitalised patients with chronic obstructive pulmonary disease and pulmonary embolism

In view of the high case fatality rates of patients with chronic obstructive pulmonary disease (COPD) who have pulmonary embolism (PE) we speculated that such patients might benefit from vena cava filters. To test this hypothesis we assessed the database of the Nationwide Inpatient Sample. From 1998–2009, 440,370 patients were hospitalised with PE and COPD who were not in shock or ventilator-dependent and did not receive thrombolytic therapy or pulmonary embolectomy. In-hospital all-cause case fatality rate among those with filters was 5,890 of 68,800 (8.6%) (95% confidence interval [CI] = 8.4–8.8) compared with 38,960 of 371,570 (10.5%) (95% CI = 10.4–10.6) (p<0.0001) who did not receive filters. Case fatality rate was age-dependent. Only those who were older than aged 50 years had a lower in-hospital all-cause case fatality rate with filters. Among such patients, absolute risk reduction was 2.1% (95% CI = 1.9–2.3). The greatest reduction of case fatality rate with vena cava filters was shown in patients >aged 80 years, 11,720 of 81,600 (14.4%) compared with 1,570 of 17,220 (9.1%) (p<0.0001). In conclusion, a somewhat lower in-hospital all-cause case fatality rate was shown with vena filters in stable patients with PE >aged 50 years who also had COPD. The benefit was greatest in elderly patients. The benefit in terms of a decreased case fatality rate would seem to outweigh the risks of vena cava filters in such patients.

Treatment of acute pulmonary embolism as outpatients or following early discharge

The purpose of this systematic review is to test the hypothesis that carefully selected low-risk patients with acute pulmonary embolism (PE) can safely be treated entirely as outpatients or after early hospital discharge.Included articles were required to describe inclusion or exclusion criteria and outcome of patients treated for PE.Early hospital discharge was defined as an average hospital stay ≤3 days.Six investigations included patients with PE who were treated entirely as outpatients; two investigations included patients with PE who were treated after early discharge. All investigations included only low-risk patients or patients with small or medium sized PE. Outcome after 3-46 months in patients treated entirely as outpatients showed recurrent PE in 0% to 6.2% of patients, major bleeding in 0% to 2.8% with one death from an intracerebral bleed. Definite death from PE did not occur, but there was one possible death from PE. Outcome in three months in patients treated after early discharge showed no instances of recurrent PE. Major bleeding occurred in 0% to 3.7% of patients.There were no deaths from PE, but there was one death from bleeding. In conclusion, outpatient therapy of acute PE is probably safe in low-risk,carefully selected compliant patients who have access to outpatient care if necessary. Such outpatient treatment would be cost-effective.

In-Hospital Mortality with Deep Venous Thrombosis

BACKGROUND

Little is known about the in-hospital mortality of deep venous thrombosis in recent years. This investigation was undertaken to determine trends in in-hospital mortality in patients with deep venous thrombosis and mortality according to age.

METHODS

Administrative data were analyzed from the National (Nationwide) Inpatient Sample, 2003-2012. We determined in-hospital all-cause mortality according to year and age among patients with a primary (first-listed) diagnosis of deep venous thrombosis. We analyzed all such patients and we analyzed those who had none of the comorbid conditions listed in the Charlson Comorbidity Index.

RESULTS

From 2003-2012, 1,603,690 hospitalized patients had a primary diagnosis of deep venous thrombosis. All-cause in-hospital mortality decreased from 1.3% in 2003 to 0.6% in 2012. Mortality increased with age from 0.1% in those aged 18-20 years to 1.5% in those over age 80 years. All-cause in-hospital mortality in those with no comorbid conditions according to the Charlson Comorbidity Index (1,094,184 patients) decreased from 1.1% in 2003 to 0.5% in 2012. Presumably, these deaths were from pulmonary embolism. All-cause mortality in those with no comorbid conditions increased with age from 0.1% in those aged 18-20 years to 1.4% in those over aged 80 years.

CONCLUSION

All-cause death and death due to pulmonary embolism in patients hospitalized with a primary diagnosis of deep venous thrombosis decreased from 2003-2012. The death rate increased with age. The decreased mortality over the period of investigation may have resulted from a shift toward use of low-molecular-weight heparins and newer anticoagulants.

Inferior Vena Cava Filters in Elderly Patients with Stable Acute Pulmonary Embolism

BACKGROUND

Patients aged >60 years with pulmonary embolism who were stable and did not require thrombolytic therapy were shown to have a somewhat lower in-hospital all-cause mortality with vena cava filters. In this investigation we further assess mortality with filters in stable elderly patients.

METHODS

In-hospital all-cause mortality according to use of inferior vena cava filters was assessed from the National (Nationwide) Inpatient Sample, 2003-2012, in: 1) All patients with pulmonary embolism; 2) All with pulmonary embolism who had none of the comorbid conditions listed in the Charlson Comorbidity Index; 3) Patients with a primary (first-listed) diagnosis of pulmonary embolism, and 4) Patients with a primary diagnosis of pulmonary embolism and none of the comorbid conditions listed in the Charlson Comorbidity Index.

RESULTS

From 2003-2012, 2,621,575 stable patients with pulmonary embolism were hospitalized in the US. Patients aged >80 years showed lower mortality with vena cava filters (all pulmonary embolism, 6.1% vs 10.5%; all pulmonary embolism with no comorbid conditions, 3.3% vs 6.3%; primary pulmonary embolism, 4.1% vs 5.7%; primary pulmonary embolism with no comorbid conditions, 2.1% vs 3.7%; all P <.0001). In the all-patient category, patients aged 71-80 years showed somewhat lower mortality with filters, 6.3% vs 7.4% (P <.0001), and those without comorbid conditions, 2.5% vs 2.8% (P = .04). Those aged 71-80 years with primary pulmonary embolism, irrespective of comorbid conditions, did not show lower mortality with filters.

CONCLUSION

At present, in the absence of a randomized controlled trial, it seems prudent to consider a vena cava filter in very elderly (aged >80 years) stable patients with acute pulmonary embolism.

National Trends in Home Treatment of Acute Pulmonary Embolism

BACKGROUND

Management of patients with acute pulmonary embolism has evolved from obligatory hospitalization to home treatment of carefully selected low-risk patients. The purpose of this investigation is to determine national trends in the prevalence of home treatment of pulmonary embolism.

METHODS

The Nationwide Emergency Department Sample was used to determine the number of patients seen in emergency departments throughout the United States with a primary (first-listed) diagnosis of pulmonary embolism and the proportion hospitalized according to age, from 2007 to 2012. The National (Nationwide) Inpatient Sample was used to determine in-hospital all-cause mortality and length of stay of hospitalized patients. Patients were adults (≥18 years) of both genders and all races from all regions of the United States. Excluded patients were those in shock or on ventilator support. International Classification of Diseases, Ninth Revision, Clinical Modification codes were used to identify patients and comorbid conditions.

RESULTS

Home treatment was selected for 54 494 (6.0%) of 915 702 stable patients with acute pulmonary embolism. The proportion of patients treated at home was age-dependent, highest in those aged 30 years or younger, 12.1%, and lowest in those >80 years, 2.9%. Most patients treated at home, 66.8%, and had no comorbid conditions. In-hospital all-cause deaths were 2.6%. Deaths were ≤0.9% in those ≤40 years and 4.8% in those >80 years. Length of stay was 6 days or longer in 37.6% of patients.

CONCLUSION

In view of the lower death rate among younger patients, they might be a group in whom home treatment would be more advantageous than in elderly patients.

Home Treatment of Pulmonary Embolism in the Era of Novel Oral Anticoagulants

BACKGROUND

Outpatient therapy of patients with acute pulmonary embolism has been shown to be safe in carefully selected patients. Problems related to the injection of low-molecular-weight heparin at home can be overcome by use of novel oral anticoagulants. The purpose of this investigation is to assess the prevalence of home treatment in the era of novel oral anticoagulants.

METHODS

This was a retrospective cohort study of patients aged ≥18 years with acute pulmonary embolism seen in 5 emergency departments from January 2013 to December 2014.

RESULTS

Pulmonary embolism was diagnosed in 983 patients. Among these, 237 were considered ineligible for home treatment because of instability or hypoxia. Home treatment was selected for 13 of 746 (1.7%) patients who were potentially eligible. Anticoagulant treatment for those treated at home was low-molecular-weight heparin or warfarin in 9 (69.2%) and novel oral anticoagulants in 4 (30.8%). Hospitalization was chosen for 733 of 746 (98.3%). Discharge in ≤2 days was in 119 patients (16.2%). Treatment of these patients was low-molecular-weight heparin or warfarin in 76 (63.9%), novel oral anticoagulants in 34 (28.6%), and in 9 (7.6%), anticoagulants were not given because of metastatic cancer or treatment was not known.

CONCLUSION

Even in the era of novel oral anticoagulants, the vast majority of patients with acute pulmonary embolism were hospitalized, and only a small proportion were discharged in ≤2 days. Although home treatment has been found to be safe in carefully selected patients, and scoring systems have been derived to identify those at low risk of adverse events, home treatment was infrequently selected.

Follow-up CT pulmonary angiograms in patients with acute pulmonary embolism

Computed tomographic (CT) angiography is associated with a non-negligible lifetime attributable risk of cancer. The risk is considerably greater for women and younger patients. Recognizing that there are risks from radiation, the purpose of this investigation was to assess the frequency of follow-up CT angiograms in patients with acute pulmonary embolism. This was a retrospective cohort study of patients aged ≥18 years with acute pulmonary embolism seen in three emergency departments from January 2013 to December 2014. Records of all patients were reviewed for at least 14 months. Pulmonary embolism was diagnosed by CT angiography in 600 patients. At least one follow-up CT angiogram in 1 year was obtained in 141 of 600 (23.5 %). Two follow-ups in 1 year were obtained in 40 patients (6.7 %), 3 follow-ups were obtained in 15 patients (2.5 %), and 4 follow-ups were obtained in 3 patients (0.5 %). Among young women (aged ≤29 years) with pulmonary embolism, 10 of 21 (47.6 %) had at least 1 follow-up and 4 of 21 (19.0 %) had 2 or more follow-ups in 1 year. Among all patients, recurrent pulmonary embolism was diagnosed in 15 of 141 (10.6 %) on the first follow-up CT angiogram and in 6 of 40 (15.0 %) on the second follow-up. Follow-up CT angiograms were obtained in a significant proportion of patients with pulmonary embolism, including young women, the group with the highest risk. Alternative options might be considered to reduce the hazard of radiation-induced cancer, particularly in young women.

Home Treatment of Deep Venous Thrombosis According to Comorbid Conditions

BACKGROUND

Cautious exploration of the safety of home treatment of deep venous thrombosis has been recommended by many. Our goal was to identify categories of patients with deep venous thrombosis who typically are hospitalized, and categories frequently treated at home.

METHODS

The Nationwide Emergency Department Sample and the Nationwide Inpatient Sample, 2007-2012, were used to determine the number of patients seen in emergency departments throughout the US with deep venous thrombosis and no diagnosis of pulmonary embolism, the proportion of such patients hospitalized according to comorbid conditions and age, the proportion discharged early (≤2 days), and charges for hospitalization and emergency department visits.

RESULTS

From 2007-2012, home treatment was selected for 905,152 of 2,671,452 (33.9%) patients with deep venous thrombosis. Home treatment was more frequent in those with no comorbid conditions than with comorbid conditions, 58.0% compared with 15.5% (P <.0001). Early discharge (≤2 days) was in 23.9% with no comorbid conditions, compared with 12.8% with comorbid conditions. Among patients aged 18-50 years, home treatment was selected in 62.9% with no comorbid conditions, compared with 24.2% with comorbid conditions (P <.0001). Among hospitalized patients with no comorbid conditions, 40.7% were aged 18-50 years. Their charges for hospitalization in 2012 were $494 million.

CONCLUSION

Patients aged 50 years or younger with deep venous thrombosis and no comorbid conditions appear to be a group that can be targeted for more frequent home treatment, which would save millions of dollars.

Home treatment of deep venous thrombosis in the era of new oral anticoagulants

This is a retrospective cohort study of adults with a primary diagnosis of deep venous thrombosis (DVT) unaccompanied by pulmonary embolism (PE), seen in 4 emergency departments in 2013 and part of 2014. The purpose was to assess the prevalence of home treatment of DVT in the present era of new oral anticoagulants. Among 96 patients with DVT and no PE, 85 (88.5%) were hospitalized and 11 (11.5%) were discharged to home. Most of the patients discharged to home received low-molecular-weight heparin, 9 (81.8%) of 11. None were prescribed new oral anticoagulants. Early discharge in ≤2 days occurred 28 (32.9%) of 85 patients. Most (64.3%) received enoxaparin and/or warfarin at early discharge. Rivaroxaban was prescribed in 7 (25.0%) of those discharged in ≤2 days. We conclude that in some emergency departments, patients with DVT are uncommonly discharged to home even though new oral anticoagulants are available.

Scope of problem of pulmonary arterial hypertension

BACKGROUND

As with many uncommon diseases, data in patients with pulmonary arterial hypertension are sparse in regard to emergency service visits, hospitalizations, and mortality. The purpose of this investigation is to assess the scope of the problem of Group 1 pulmonary arterial hypertension in adults in the US and trends from 2001 to 2007.

METHODS

The Nationwide Emergency Department Sample, 2007-2011, was used to determine the number of emergency department visits, hospitalizations, and all-cause mortality of patients aged ≥18 years with Group 1 pulmonary arterial hypertension. We assessed patients with a discharge code for "primary pulmonary hypertension," and excluded patients with known causes of pulmonary hypertension that are not classified as Group 1.

RESULTS

There were 64,451 emergency department visits and 52,779 hospitalizations for pulmonary arterial hypertension from 2007-2011 in patients aged ≥18 years. The proportion of all emergency department visits that were for pulmonary arterial hypertension decreased from 16.4/100,000 visits in 2007 to 8.9/100,000 visits in 2011 (P < .0001). The proportion of all hospitalizations that were for pulmonary arterial hypertension decreased from 79/100,000 hospitalizations in 2007 to 38/100,000 hospitalizations in 2011 (P < .0001). Population-based death rates in patients with pulmonary arterial hypertension decreased from 4.6/million population in 2007 to 1.7/million population in 2011 (P < .0001).

CONCLUSIONS

Decreasing rates of emergency department visits, hospitalizations, and deaths in patients with Group 1 pulmonary arterial hypertension were shown from 2007-2011. We speculate that this resulted from improved treatment during the period of observation.

Sinus of Valsalva: a converging nozzle that contributes to stable flow in the coronary arteries

The anatomy of the sinuses of Valsalva has not been considered from the viewpoint of a converging nozzle. Converging nozzles reduce turbulence. We reviewed computed tomographic images of the left and right sinuses of Valsalva in 20 consecutive patients. The sinuses of Valsalva were shown to have a shape in the axial projection that approximates a cubic equation nozzle, although the sinuses of Valsalva are not axisymmetric. The ratios of the cross-sectional area of the inlet to cross-sectional areas of the outlet, assuming the sinuses are axisymmetric, were 14 and 17 in the left and right sinuses, respectively. Calculations by others show that turbulent kinetic energy at the exit (at the coronary ostia) of such axisymmetric nozzles would be reduced by 97%. We conclude that the sinuses of Valsalva have the configuration of a converging nozzle and prevent or reduce turbulent flow in the proximal portions of the coronary arteries.

Pulmonary embolectomy in elderly patients

OBJECTIVE

The relation of age to case fatality rate in patients undergoing pulmonary embolectomy has not been reported. In view of the importance of age in the selection of patients who may be candidates for pulmonary embolectomy, we explored the database of the Nationwide Inpatient Sample to determine the impact of age on the case fatality rate.

METHODS

Patients with pulmonary embolism who underwent pulmonary embolectomy in short-stay hospitals throughout the United States, 1999-2008, were identified from the Nationwide Inpatient Sample. In-hospital all-cause case fatality rate was assessed according to age.

RESULTS

The proportion of patients who underwent pulmonary embolectomy decreased with age among both stable and unstable patients. Case fatality rate with pulmonary embolectomy in stable patients increased with age beginning at age 51 to 60 years. Among patients aged 51 to 60 years, the case fatality rate was 100 of 575 (17.4%). This rate increased to 60 of 130 (46.2%) among patients aged more than 80 years (P < .0001). The case fatality rate did not correlate with age in unstable patients.

CONCLUSIONS

The case fatality rate with pulmonary embolectomy in stable patients increases with age greater than 51 to 60 years and is high among the elderly. The case fatality rate with pulmonary embolectomy in unstable patients does not seem to be related to age.

Vena cava filters in unstable elderly patients with acute pulmonary embolism

BACKGROUND

Inferior vena cava filters are associated with a reduced in-hospital all-cause case fatality rate of unstable patients with acute pulmonary embolism. Whether vena cava filters are associated with a reduced case fatality rate in adults of all ages with unstable pulmonary embolism, particularly the elderly, has not been determined.

METHODS

Unstable patients with pulmonary embolism (in shock or ventilator dependent) 1999-2008 were identified from the Nationwide Inpatient Sample.

RESULTS

Among 21,095 unstable patients with pulmonary embolism who received thrombolytic therapy, in-hospital all-cause case fatality rate was lower in every age group who received a vena cava filter in addition to thrombolytic therapy (P = .0012 to <.0001). Patients aged ≥ 81 years showed the greatest absolute reduction of case fatality rate with filters (19.3%). Among 50,210 unstable patients who did not receive thrombolytic therapy, case fatality rate also was lower in every age group who received a vena cava filter (all P <.0001). Patients aged ≥ 81 years with vena cava filters showed the greatest absolute risk reduction of case fatality rate (27.7%).

CONCLUSION

Vena cava filters are associated with a reduced in-hospital all-cause case fatality rate in unstable adults with pulmonary embolism, irrespective of age.

Relation of electrocardiographic changes in pulmonary embolism to right ventricular enlargement

The electrocardiographic (ECG) findings in patients with pulmonary embolism (PE) and no previous cardiopulmonary disease are well documented; however, investigation of the relation of ECG abnormalities to right ventricular (RV) enlargement has been limited. The purpose of the present investigation was to assess further the relation of ECG changes in acute PE to RV cavity enlargement (dilation). The records of patients hospitalized from January 2009 to December 2012 with acute PE and no previous cardiopulmonary disease were reviewed. A total of 289 patients were included. RV cavity enlargement was present in 141 patients (49%). Normal ECG findings were less prevalent in patients with PE and RV enlargement than those with PE and no RV enlargement (35 of 141 [25%] vs 56 of 148 [38%]; p = 0.02). One or more of the traditional ECG manifestations of acute cor pulmonale (S1Q3T3, complete right bundle branch block, P pulmonale, or right axis deviation) was found in 18 of 141 patients (13%) with RV enlargement and 13 of 148 (8.8%) with a normal size RV (p = NS). None of the ECG abnormalities was sensitive for RV enlargement. The specificity of P and QRS abnormalities was high. The positive predictive values were ≤83% or had wide 95% confidence intervals. The negative predictive values ranged from 50% to 61%. In conclusion, ECG findings were not useful for the detection or exclusion of RV cavity enlargement in patients with acute PE.

Pulmonary embolism and deep venous thrombosis following laparoscopic cholecystectomy

There is considerable uncertainty related to the thromboembolic risk after laparoscopic cholecystectomy. Patients with pulmonary embolism (PE), deep venous thrombosis (DVT), or venous thromboembolism (VTE) at hospital discharge following laparoscopic cholecystectomy were identified from the Nationwide Inpatient Sample. From 1998 through 2009, 4 107 430 laparoscopic cholecystectomies were performed. The in-hospital prevalence of PE was 0.15%, DVT was 0.40%, and VTE was 0.53%. The prevalence of PE increased from 0.04% in patients aged 21 to 30 years to 0.31% in patients aged 71 to 80 years. Deaths due to in-hospital PE were 780 (0.02%) of the 4 107 430 laparoscopic cholecystectomies. The rate of death increased with age. The prevalence of VTE following laparoscopic cholecystectomy is low and fatal PE is rare. The risk of VTE increased with age, as did the risk of death in those who had PE. These data may be useful in assessing the use of thromboprophylaxis in patients undergoing laparoscopic cholecystectomy.

Specificity of quantitative latex agglutination assay for D-dimer in exclusion of pulmonary embolism in the emergency department

We assessed the prevalence of elevated quantitative latex agglutination assay for D-dimer in patients in the emergency department in whom pulmonary embolism (PE) was excluded. D-dimer was normal (<230 ng/mL) in 435 (83%) of the 522 patients. D-dimer was normal in 88% of the patients with musculoskeletal or related chest pain, 74% with pleurisy or pleuritic chest pain, and 85% with upper respiratory tract infection. D-dimer was 230 to 500 ng/mL in 65 (75%) of the 87 in whom D-dimer was elevated. Clinical probability was low in 31 (48%) of the 65 patients with D-dimer levels of 230 to 500 ng/mL. D-dimer was 230 to 500 ng/mL and clinical probability was low in 31 (36%) of the 87 patients who had computed tomographic (CT) angiograms because of elevated D-dimer. Negative likelihood ratio for PE is sufficiently low that PE can be excluded with reasonable certainty in such patients. Tailoring cutoff value to 500 ng/mL in patients with low clinical probability would have reduced CT angiograms by 36%.