More Evidence of Stroke Risk After Hip Replacement

Megan Brooks

Nov 14, 2012 Authors & Disclosures

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Patients who undergo total hip replacement have a greater than 4-fold increased risk for ischemic or hemorrhagic stroke during the first 2 postoperative weeks, according to a new study.

In addition, the risk remains elevated for at least 6 weeks for ischemic stroke and 12 weeks for hemorrhagic stroke. Antiplatelet therapy seems to protect against ischemic stroke after hip replacement.

"This research has demonstrated that there is a high risk of stroke to patients soon after having a total hip replacement and suggests that the use of soluble aspirin might be beneficial in reducing this risk," Frank de Vries, PharmD, PhD, Division of Pharmacoepidemiology and Clinical Pharmacology, Utrecht Institute for Pharmaceutical Sciences, the Netherlands, told Medscape Medical News.

"Normally, we would have reservations about people taking aspirin every day but our results suggest aspirin is a benefit and worthwhile," Dr. de Vries said.

Nonetheless, in the paper they note that the "seemingly protective" effect of aspirin should be interpreted with caution, given the observational design of the study and the lack of information on inpatient antithrombotic use.

The study is published online November 6 in Stroke.

Pick Your Poison

"Staying on aspirin increases bleeding and hemorrhagic stroke risk postop and going off aspirin increases clotting complications like MI [myocardial infarction] and stroke. Pick your poison," commented Richard Iorio, MD, chief of Adult Reconstruction, Department of Orthopedic Surgery, New York Langone Medical Center, Hospital for Joint Diseases, New York City, and member of the American Academy of Orthopaedic Surgeons. Dr. Iorio was not involved in the study.

The researchers note that previous studies have also found an increased risk for stroke after hip replacement. However, the timing of stroke after hip replacement compared with matched controls and the influence of antiplatelet and anticoagulant use remained unclear, until now.

Using the Danish registry data, the investigators evaluated the risk for stroke in 66,583 patients who had total hip replacement compared with 199,995 who had not had the surgery but were matched for age, sex, and geographic region. The mean age of study participants was 72 years, and 63% of patients were women.

In the first 2 weeks after surgery, the adjusted hazard ratios were 4.69 (95% confidence interval [CI], 3.12 - 7.06) for ischemic stroke and 4.40 (95% CI, 2.01- 9.62) for hemorrhagic stroke.

"For both types of stroke, the risk dropped steadily afterward, but remained significantly elevated during at least the first 6 postoperative week for ischemic stroke, and the first 12 weeks for hemorrhagic stroke," the investigators report.

"We've known for a long time that there is a certain time after surgery that patients become thrombophilic and are a little bit more prone to having a stroke or some thromboembolic event and this paper documents that," Dr. Iorio told Medscape Medical News.

Surgeon's Choice

Dr. de Vries and colleagues also observed that surgery patients dispensed antiplatelet drugs experienced a 70% reduction in the risk for ischemic stroke during the first 6 postoperative weeks compared with those who had not been dispensed any antithrombotic agents. Antiplatelet use didn't affect hemorrhagic stroke risk.

"Some surgeons stop aspirin before the surgery, some don't," Dr. Iorio said. "I happen to be someone that doesn't stop aspirin before surgery."

It makes sense to evaluate the risk for stroke during the first 6 to 12 weeks after surgery, Dr. Dr. de Vries and colleagues conclude.

The study was funded by the Netherlands Organization for Scientific Research. The authors and Dr. Iorio have disclosed no relevant financial relationships.

Stroke. Published online November 6, 2012. Abstract