The diagnosis and prognosis of venous thromboembolism : variations on a theme - Chapter 11: Treatment of pulmonary embolism in the Netherlands; a survey

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The diagnosis and prognosis of venous thromboembolism : variations on a

theme

Gibson, N.S.

Publication date

2008

Link to publication

Citation for published version (APA):

Gibson, N. S. (2008). The diagnosis and prognosis of venous thromboembolism : variations

on a theme.

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Treatmentofpulmonaryembolism

intheNetherlands;asurvey

NADINES.GIBSON,RENÉEDOUMA,LISHIAOEI, DAPHNEBOOM,MAAIKESÖHNE,HARRYR.BÜLLER

    SUBMITTED

150

A

BSTRACT



Background

Littleinformationisavailableonthecurrenttreatmentapproachesinpatientswith pulmonary embolism. We therefore performed a survey in the Netherlands and assessedcharacteristicsofthetreatmentofpatientswithpulmonaryembolism. 

Methods

We collected detailed information about the first ten patients treated in 2006 for pulmonary embolism in 14 hospitals, varying from academic centers to non teaching. We assessed the clinical characteristics of the hospitalized and home treatedpatients,andthedurationofhospitalstay.Furthermore,weanalyzedthe initialandlongtermtreatmentofthepatientsandfactorsthatcouldhavelettoa specifictreatmentchoice.



Results

Of the 140 consecutive patients, eight (6%) were not admitted, whereas the remaining 132 were treated in hospital for a median duration of 7 days. Differencesintheclinicalcharacteristicsofthepatientstreatedforlessorformore thanoneweekinthehospitalwereahighermeanage(p<0.05)andsurgeryinthe recenthistory(p=0.05).

Of the 129 patients that started with low molecular weight heparin, 16 patients (12%) received it less than 5 days. Previous venous thromboembolism and malignancy appeared to be considerations to extend the treatment to a year or longer.



Conclusion

In 2006 almost all patients with pulmonary embolism were treated in hospital. Further research should focus on the development and implementation of tools thatcanaidphysiciansinthefirstdaysofhospitaladmissioninassessingtherisk ofadverseeventandsubsequentlytheabilitytotreatpatientsathome.

TreatmentofpulmonaryembolismintheNetherlands



I

NTRODUCTION



Until the introduction of subcutaneous low molecular weight heparin (LMWH), patientswitheitherdeepvenousthrombosisorpulmonaryembolismwereadmitted tohospitalforaninitialtreatmentwithintravenousunfractionatedheparin(UFH)for

at least 7 to 10 days1_{. In those with deep venous thrombosis there has been a major}

shifttowardshometreatmentfollowingthisintroductionofLMWH2_{.Althoughdeep}

venous thrombosis and pulmonary embolism are considered manifestations of a single disease entity, physicians are reluctant to apply a similar strategy in patients

withpulmonaryembolism,despitetheavailabilityofsomestudies35_.

This hesitation to treat patients with pulmonary embolism at home may be partly explainedbythehigherknowncasefatalityrateduetofatalpulmonaryembolismin the firsttwoweeks after diagnosis relative to patients with deep venous thrombosis

(1.5%and0.4%,respectively)6_{.Ontheotherhandpredictionrulesthatselectpatients}

with a low risk for adverse events, that are eligible for home treatment have been

introduced7,8_{. In addition to the lack of knowledge about the frequency of home}

treatment, surprisingly little information is available on the current treatment approachesindailyclinicalpracticeinpatientswithprimarypulmonaryembolism. We, therefore, performed a survey in 14 Dutch hospitals. Patient characteristics, frequencyofhometreatment,meandurationofhospitalstayifadmitted,thetypeand durationofinitialandlongtermanticoagulanttreatment,wereassessed.

M

ETHODS



Patients

Toobtainarepresentativesampleofpatientstreatedwithpulmonaryembolisminthe Netherlands, we collected detailed information from 14 hospitals, varying from academic centers to nonteaching hospitals. In each center the first ten consecutive patientsthatwerediagnosedwithpulmonaryembolismin2006,wereincludedinthe presentanalysis,usinginformationfromelectronichospitalrecords.

Twotrainedresearcherscollectedalldatawiththehelpofastructuredclinicalreport form.

Thisformcontainedquestionsontheclinicalcharacteristicsandtheriskfactorsthat could have led to development of the disease. Furthermore patient’s hemodynamic statusandtreatmentstrategies,eitherathomeorinhospitalwereretrieved.

152

Table 1. Clinical characteristics of the 140 patients treated for documented pulmonary embolism.

Characteristics n (%)

Mean age, years (range) 59 (21-91)

Female 76 (54)

Median duration of complaints, days (IQR) 3 (1-7)

Idiopathic episode 63 (45)

History of venous thromboembolism 43 (31)

Surgery in the recent history 25 (18)

Malignancy 19 (14)

COPD 12 (9)

Heart failure 7 (5)

Outpatients 115 (82)

Analysis

Descriptive statistics were applied using SPSS version 14.0.2. The clinical characteristics of the hospitalized and home treated patients were assessed. The durationofhospitalstaywascalculatedanddividedintwocategoriestocomparethe clinical characteristics of the patients. Furthermore, we analyzed the proportion of patientsthatreceivedvariousinitialtreatmenttherapies.Finally,thedurationoflong term treatment was analyzed together with the factors that could have led to the choiceforaspecifictreatmentduration.

R

ESULTS



Patients

The clinical characteristics of the 140 consecutive study patients diagnosed with pulmonary embolism are detailed in Table 1. The mean age was 59 years, and little morethanhalfwerefemale.Themedianintervalbetweentheonsetofsymptomsand diagnosis was three days. Fortyfive percent of the patients experienced idiopathic pulmonary embolism, whereas the etiological factors in those patients with a provoked episode included recent surgery or immobilisation (20 patients), malignancy (17), hormone therapy (14) and long distance travel (6). The treating specialists of the 140 study patients were pulmonologists (59%), internists (35%), cardiologists(4%)andsurgeonsandothers(2%).Atotalof36%ofthestudypatients were seen in academic centers, 36% in nonacademic teaching hospitals, and 29% in nonteachinghospitals.

TreatmentofpulmonaryembolismintheNetherlands



Figure 1. Distribution of the duration of stay for the 132 patients with pulmonary embolism

treated in hospital.

Hospital stay

Eight patients (6%) were not admitted and treated entirely at home. The remaining 132patientswerehospitalized(ofwhom108wereoutpatients)withameanduration ofhospitalstayof8.2days(SD6.2;range152days;median7.0;Figure1).Theclinical characteristicsofthepatientsthatweretreatedinhospitalforlessthan7daysdidnot differfromthosewhostayedlonger,withtheexceptionofaslightlyhighermeanage (p<0.05)andarecenthistoryofsurgery(p=0.05)inthosewhostayedlonger(Table2). The eight patients that were treated at home were hemodynamically stable, did not need supplemental oxygen and had no comorbid conditions. Six of these patients camefromtwohospitals.

Initial anticoagulant treatment

Twentysix patients were described as being hemodoynamically unstable at presentation.Ofthese,twoweretreatedwiththrombolysis(alteplaseandmetalyse). Atotalof129patients(97%)receivedLMWHsubcutaneously,andtheremainingnine patients started with UFH. Of these latter, eight received subsequently LMWH, usuallyafter onetotwodays.Themeanduration ofLMWHtreatmentonlywas7.5 days(SD4.5)witharangeof325days;atotalof16patients(12%)receivedLMWH forlessthan5days. 20 15 10 5 0 Proportion of pa tients (%)

154

Table 2. Clinical characteristics of the patients that stayed less or more than a week in hospital.

< 7 days (n=54) n (%)

 7 days (n=78) n (%)

P-value

Mean age, years (range) 55 (22-91) 61 (21-90) 0.04

Median duration of complaints 3 (1-4.25) 3 (1-7) 0.37

Idiopathic episode 23 (43) 35 (45) 0.88

History of venous thromboembolism 19 (34) 22 (28) 0.45

Surgery in the recent history 6 (11) 17 (22) 0.05

Malignancy 6 (11) 13 (17) 0.46

COPD 3 (6) 9 (12) 0.18

Heart failure 2 (4) 5 (6) 0.14

Supplemental oxygen 14 (26) 30 (38) 0.29

Hemodynamically unstable 8 (15) 18 (23) 0.89

Long term treatment

All patients received vitamin K antagonists (VKA) with acenocoumarol in 77% and phenprocoumon in 33% of the patient. A total of 3 patients (2%) were treated for 3 months, the majority (71 patients; 51%) received VKA for six ±1 month, whereas 25 patients(18%)weretreatedfortwelve±3monthsandtheremaining40patients(29%) received indefinite treatment. Table 2 describes the possible factors that may determine the duration of long term treatment. Previous venous thromboembolism and the presence of malignancy appeared to be considerations for prolonged treatment.ThemeantimeuntilatherapeuticINRwasobtainedwas7.8days witha rangeof219days.

D

ISCUSSION



Oursurveyin140patientstreatedforpulmonaryembolismallowsforthefollowing inferences. The clinical characteristics are very similar to those reported in recent

clinicaltrialsandpulmonaryembolismregistries911_{.Furthermoreweaimedtoobtain}

a population based sample by the selection of hospitals included for the survey. Thereforewebelievethatourfindingsareapplicableforallpatientswithpulmonary embolism.



The most surprising finding is that in 2006, 94% of all patients with pulmonary embolismwereadmittedandstayedforameandurationofeightdaysinhospital.It was not immediately apparent what the considerations were of physicians to treat

TreatmentofpulmonaryembolismintheNetherlands



Table 3. Possible factors in percentages that may determine the treatment duration.

patients in hospital for either less than 7 days or more than 7 days (Table 2). An explanation could be that patients are hospitalized for a certain period, due to a routine setting of admitting patients with pulmonary embolism, rather than clinical considerations.



Regarding initial treatment only two of the 140 patients (1.4%) were treated with thrombolysis, albeit that another 24 patients were described as being hemodynamicallyunstable.UFHwasusedinfrequentlyandoftenonlyinthefirsttwo days. The initial treatment duration with LMWH, with a mean of 7.5 days, is

comparable to what has been reported in previous studies12_{. A total of 12% of the}

patients did not use LMWH for at least five days, as is advised in several

guidelines13,14_.



Treatment durations with VKA were generally according to current international guidelines,exceptfortheinfrequenttreatmentdurationof3monthsinonly2%ofthe patients, whereas 55% were diagnosed with a provoked episode of pulmonary embolism.AnotherobservationisthataboutonethirdofthepatientsreceivedVKA foranindefiniteperiod,whichappearstobehighalthoughitisunclearwhetherthere wasaclusteringinthesepatientsofriskfactorsthatmayjustifythisdecision.Table3 suggests that previous venous thromboembolism and malignancy are important factorstoprolongVKAtreatmentbeyondsixmonths.



Our observations clearly indicate that further education is necessary if the goal is to treatmorepatientsoutofhospital.Furtherresearchshouldfocusonthedevelopment and implementation of tools that can aid physicians in the first days of hospital admissioninassessingtheriskofadverseeventandsubsequentlytheabilitytotreat patientsathome. Three months (n=3) Six months ± one month (n=72) Twelve months ± three months (n=25) Indefinite period (n=40)

History of venous thromboembolism 0 6 58 60

Malignancy 33 2 16 20

156

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