Knee or Hip Replacement Cuts Heart Risks

http://well.blogs.nytimes.com/2013/11/14/knee-or-hip-replacement-cuts-heart-risks/
Knee or Hip Replacement Cuts Heart Risks

By NICHOLAS BAKALAR

For people with severe arthritis, knee or hip replacement may have an added benefit: a reduction in the risk for cardiovascular disease.

Canadian researchers selected 153 people with moderate to severe osteoarthritis who had had a knee or hip replacement and 153 who had not. The groups were matched for severity of arthritis, age, income, smoking status, diabetes and other factors.

Then the researchers followed them for seven years, during which there were 111 instances of a serious cardiovascular event — heart attack, stroke, heart failure, coronary artery bypass surgery, angioplasty or death from cardiovascular disease. The study was posted online in BMJ, the medical journal.

Compared with those who had neither knee nor hip surgery, those who had an operation were 40 percent less likely to have a cardiovascular event. Patients who had at least one risk factor for cardiovascular disease also benefited — joint replacement operations were associated with a 29 percent decreased risk of a cardiovascular events for this group.

Joint replacement has several effects that could contribute to the reduced risk, according to the lead author, Dr. Bheeshma Ravi, a resident in orthopedic surgery at the University of Toronto. “Debilitating arthritis limits the ability to exercise, which in turn leads to worse outcomes for the heart,” he said. A joint replacement reduces “pain and inflammation and even depression, all risk factors for cardiac events.”

http://www.bmj.com/content/347/bmj.f6187

RESEARCH

The relation between total joint arthroplasty and risk for serious cardiovascular events in patients with moderate-severe osteoarthritis: propensity score matched landmark analysis

BMJ 2013; 347 doi: http://dx.doi.org/10.1136/bmj.f6187 (Published 30 October 2013)

Cite this as: BMJ 2013;347:f6187

Abstract

Objective To examine whether total joint arthroplasty of the hip and knee reduces the risk for serious cardiovascular events in patients with moderate-severe osteoarthritis.

Design Propensity score matched landmark analysis.

Setting Ontario, Canada.

Participants 2200 adults with hip or knee osteoarthritis aged 55 or more at recruitment (1996-98) and followed prospectively until death or 2011.

Main outcome measure Rates of serious cardiovascular events for those who received a primary total joint arthroplasty compared with those did not within an exposure period of three years after baseline assessment.

Results The propensity score matched cohort consisted of 153 matched pairs of participants with moderate-severe arthritis. Over a median follow-up period of seven years after the landmark date (start of the study), matched participants who underwent a total joint arthroplasty during the exposure period were significantly less likely than those who did not to experience a cardiovascular event (hazards ratio 0.56, 95% confidence interval 0.43 to 0.74, P<0.001). Within seven years of the exposure period the absolute risk reduction was 12.4% (95% confidence interval 1.7% to 23.1%) and number needed to treat was 8 (95% confidence interval 4 to 57 patients).

Conclusions Using a propensity matched landmark analysis in a population cohort with advanced hip or knee osteoarthritis, this study found a cardioprotective benefit of primary elective total joint arthroplasty.