Determinants and time course of the postthrombotic syndrome after acute deep venous thrombosis.
BACKGROUND
The reason some patients with deep venous thrombosis (DVT) develop the postthrombotic syndrome is not well understood.


OBJECTIVE
To determine the frequency, time course, and predictors of the postthrombotic syndrome after acute DVT.


METHODS
Prospective, multicenter cohort study.


METHODS
8 Canadian hospital centers.


METHODS
387 outpatients and inpatients who received an objective diagnosis of acute symptomatic DVT were recruited from 2001 to 2004.


METHODS
Standardized assessments for the postthrombotic syndrome using the Villalta scale at 1, 4, 8, 12, and 24 months after enrollment. Mean postthrombotic score and severity category at each interval was calculated. Predictors of postthrombotic score profiles over time since diagnosis of DVT were identified by using linear mixed modeling.


RESULTS
At all study intervals, about 30% of patients had mild (score, 5 to 9), 10% had moderate (score, 10 to 14), and 3% had severe (score >14 or ulcer) postthrombotic syndrome. Greater postthrombotic severity category at the 1-month visit strongly predicted higher mean postthrombotic scores throughout 24 months of follow-up (1.97, 5.03, and 7.00 increase in Villalta score for mild, moderate, and severe 1-month severity categories, respectively, vs. none; P < 0.001). Additional predictors of higher scores over time were venous thrombosis of the common femoral or iliac vein (2.23 increase in score vs. distal [calf] venous thrombosis; P < 0.001), higher body mass index (0.14 increase in score per kg/m(2); P < 0.001), previous ipsilateral venous thrombosis (1.78 increase in score; P = 0.001), older age (0.30 increase in score per 10-year age increase; P = 0.011), and female sex (0.79 increase in score; P = 0.020).


CONCLUSIONS
Decisions to prescribe compression stockings were left to treating physicians rather than by protocol. Because international normalized ratio data were unavailable, the relationship between anticoagulation quality and Villalta scores could not be assessed.


CONCLUSIONS
The postthrombotic syndrome occurs frequently after DVT. Patients with extensive DVT and those with more severe postthrombotic manifestations 1 month after DVT have poorer long-term outcomes.
Kahn
Susan R
SR
Centre for Clinical Epidemiology and Community Studies, Sir Mortimer B. Davis Jewish General Hospital, Montreal, Quebec, Canada. susan.kahn@mcgill.ca
Shrier
Ian
I
Julian
Jim A
JA
Ducruet
Thierry
T
Arsenault
Louise
L
Miron
Marie-José
MJ
Roussin
Andre
A
Desmarais
Sylvie
S
Joyal
France
F
Kassis
Jeannine
J
Solymoss
Susan
S
Desjardins
Louis
L
Lamping
Donna L
DL
Johri
Mira
M
Ginsberg
Jeffrey S
JS
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000627:therapeutic use; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D054070:Postthrombotic Syndrome / Q000175:diagnosis / Q000209:etiology*; D011446:Prospective Studies; D012008:Recurrence; D012307:Risk Factors; D053828:Stockings, Compression; D013997:Time Factors; D020246:Venous Thrombosis / Q000150:complications* / Q000188:drug therapy / Q000517:prevention & control; D055815:Young Adult
D000925:Anticoagulants