Heart Failure Linked to Higher Hip Fracture Risk

By Todd Neale
EDMONTON, Alberta, 02 nov 2008 -- Older heart failure patients have an increased risk of fracture, particularly of the hip, researchers found.
Patients ages 65 and older who presented to an emergency room for heart failure were four times more likely to suffer a fracture over the next year than patients with other cardiovascular diseases (OR 4.0, 95% CI 3.0 to 5.2), Justin Ezekowitz, M.B.B.Ch., of the University of Alberta here, and colleagues reported online in Circulation: Journal of the American Heart Association.
The risk of hip fracture specifically was increased 6.3-fold (95% CI 3.4 to 11.8).
The elevated risks remained significant even after excluding patients who were using bisphosphonates.
The results suggest that "increased attention needs to be paid to the screening for and treatment of osteoporosis to reduce fracture risk in those with heart failure," the researchers said.
The reasons behind the association between heart failure and fracture remain unclear, the researchers said.
Although heart failure and fracture share some risk factors, it hadn't been known whether heart failure patients had an increased risk of fracture, according to the researchers.
So they evaluated data from 2,041 patients with a first diagnosis of heart failure and 14,253 patients with other cardiovascular disease treated at emergency rooms throughout the province of Alberta over a three-year period.
Heart failure patients were significantly older (median 78 versus 73) and more likely to have hypertension, diabetes, atrial fibrillation, prior cerebrovascular disease, peripheral vascular disease, renal disease, and chronic obstructive pulmonary disease (P≤0.001 for all).
They were also more likely to be taking ACE inhibitors or angiotensin receptor blockers, diuretics, spironolactone, vitamin K antagonists, and thyroid replacement hormones (P≤0.01 for all).
The use of bisphosphonates (P=0.04) and other osteoporosis medications (P<0.0001) was more common in the control group.
Within a year after the emergency room visit, 4.6% of the heart failure patients and 1% of the control patients sustained a fracture (P<0.001).
Hip fractures occurred in 1.3% of heart failure patients and 0.1% of the controls (P<0.001).
Aside from heart failure, other significant predictors of fracture were increasing age (OR 1.26), bisphosphonate use (OR 2.55), and female sex (OR 2.17).
Although the reasons behind the association between heart failure and fracture are unclear, the mechanism may involve elevated levels of parathyroid hormone, angiotensin II, or aldosterone and lower levels of vitamin D, the researchers said.
In addition, they said, certain cardiovascular medications -- such as beta-blockers, thiazide diuretics, and loop diuretics -- may influence the risk of osteoporosis and fracture.
"Further elucidation of the potential mechanism for increased orthopedic fracture risk in heart failure patients requires further pathophysiological studies," they said.
Regardless of the mechanism, the researchers said that the low numbers of patients receiving treatment for osteoporosis indicated that efforts needed to be undertaken to increase screening for bone loss in patients ages 65 and older.
"Although our data do not allow us to determine whether other comorbidities that coexist with or are part of the underlying pathophysiology of heart failure (e.g., anemia and malnutrition) are the cause of fracture," they said, "patients with heart failure are readily identifiable and need to have better attention paid to bone mass and amelioration of fracture risk."
They acknowledged some limitations of the study, including the use of administrative data, the possibility that patients with preexisting heart failure were placed in the control group, the inability to detect fractures treated in an outpatient setting, the fact that fall risk increases with age, the inability to track over-the-counter use of calcium and vitamin D, and potential residual bias and confounding.
Dr. Ezekowitz is supported by the Randomized Controlled Trials program of the Canadian Institutes of Health Research (CIHR). His co-authors are supported by the Alberta Heritage Foundation for Medical Research, the CIHR, and the Merck Frosst-Aventis Chair in Patient Health Management. The study was supported by an operating grant from the CIHR.
The authors made no financial disclosures.
Primary source: Circulation: Journal of the American Heart AssociationSource reference:Van Diepen, et al "Heart failure is a risk factor for orthopedic fracture: a population-based analysis of 16,294 patients" Circulation 2008; DOI: 10.1161/CIRCULATIONAHA.108.784009.