Inhibition of renin angiotensin axis may be associated with reduced risk of developing venous thromboembolism in patients with atherosclerotic disease.
BACKGROUND
Arterial and venous thrombosis may share common pathophysiology involving the activation of platelets and inflammatory mediators. A growing body of evidence suggests prothrombotic effect of renin angiotensin system (RAS) including vascular inflammation and platelet activation. We hypothesized that the use of angiotensin converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) plays a role in protecting against venous thromboembolism (VTE) in patients atherosclerosis.


METHODS
We conducted a retrospective study, reviewing 1,100 consecutive patients admitted to a teaching hospital with a diagnosis of either myocardial infarction or ischemic stroke from 2005 to 2010. Patients who had been treated with anticoagulation therapy before or after the first visit were excluded. The occurrence of VTE during the follow up period, risk factors for VTE on admission, and the use of ACEIs or ARBs during the follow up period were recorded.


RESULTS
The mean age of the entire study population was 68.1 years. 52.0% of the patients were female and 76.5% were African American. 67.3% were on RAS inhibitors. The overall incidence of VTE was 9.7% (n = 107). Among the RAS inhibitor users, the incidence of VTE events was 9.0% (54/603) for the ACEI only users, 7.1% (8/113) for the ARB only users, and 0% (0/24) for the patients taking combination of ACEI and ARB. Among patients on RAS inhibitors, 8.4% (62/740) developed a VTE, compared with 12.5% (45/360) in the nonuser group [HR (hazard ratio), 0.58; 95% CI (confidence interval), 0.39-0.84; P<0.01]. Even after controlling for factors related to VTE (smoking, history of cancer, and immobilization, hormone use) and diabetes, the use of RAS inhibitors was still associated with a significantly lower risk of developing VTE (AHR, 0.59; 95% CI, 0.40-0.88; P = 0.01).


CONCLUSIONS
The use of RAS inhibitors appears to be associated with a reduction in the risk of VTE.
Department of Cancer Medicine, University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America.
Young Kwang
YK
Chae
Department of Medicine, Cleveland Clinic, Ohio, United States of America.
Danai
D
Khemasuwan
Department of Medicine, Albert Einstein Medical Center, Philadelphia, Pennsylvania, United States of America.
Anastasios
A
Dimou
Department of Medicine, Albert Einstein Medical Center, Philadelphia, Pennsylvania, United States of America.
Stefan
S
Neagu
Department of Medicine, Albert Einstein Medical Center, Philadelphia, Pennsylvania, United States of America.
Lakshmi
L
Chebrolu
Department of Medicine, Albert Einstein Medical Center, Philadelphia, Pennsylvania, United States of America.
Shikha
S
Gupta
Department of Medicine, Albert Einstein Medical Center, Philadelphia, Pennsylvania, United States of America.
Alejandra
A
Carpio
Department of Medicine, Albert Einstein Medical Center, Philadelphia, Pennsylvania, United States of America.
Jongoh
J
Kim
Department of Medicine, Albert Einstein Medical Center, Philadelphia, Pennsylvania, United States of America.
Jeong Hyun
JH
Yun
Department of Medicine, Albert Einstein Medical Center, Philadelphia, Pennsylvania, United States of America.
Athanasios
A
Smyrlis
Department of Medicine, Albert Einstein Medical Center, Philadelphia, Pennsylvania, United States of America.
Alan
A
Friedman
Department of Medicine, Albert Einstein Medical Center, Philadelphia, Pennsylvania, United States of America.
William
W
Tester
D000368:Aged; D000369:Aged, 80 and over; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000008:administration & dosage*; D050197:Atherosclerosis / Q000150:complications / Q000188:drug therapy*; D002545:Brain Ischemia / Q000150:complications / Q000188:drug therapy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications / Q000188:drug therapy; D012084:Renin-Angiotensin System / Q000187:drug effects*; D012189:Retrospective Studies; D012307:Risk Factors; D020521:Stroke / Q000150:complications / Q000188:drug therapy; D054556:Venous Thromboembolism / Q000209:etiology / Q000517:prevention & control*
D000806:Angiotensin-Converting Enzyme Inhibitors