Association of Alendronate and Risk of Cardiovascular Events in Patients With Hip Fracture.

The risk of cardiovascular events (CVEs) with alendronate use in real-world hip fracture patients is unknown. This study aimed to investigate the risk of CVE with and without use of alendronate in patients with hip fracture. We conducted a retrospective cohort study using a population-wide database managed by the Hong Kong Hospital Authority. Patients newly diagnosed with hip fracture from 2005 through 2013 were followed until November 6, 2016. Alendronate and other antiosteoporosis medications use during the study period were examined. We matched treated and nontreated patients based on time-dependent propensity score. The risks of cardiovascular mortality, myocardial infarction, and stroke between treatment groups were evaluated using conditional Cox regression stratified by match pairs. To examine the associations over time, outcomes were assessed at 1 year, 3 years, 5 years, and 10 years. Among 34,991 patients with newly diagnosed hip fracture, 4602 (13.2%) received antiosteoporosis treatment during follow-up. Physical functioning or survival prospect was not significantly different between treated and nontreated patients. A total of 4594 treated patients were matched with 13,568 nontreated patients. Results of Cox regression analysis revealed that alendronate was associated with a significantly lower risk of 1-year cardiovascular mortality (HR 0.33; 95% CI, 0.17 to 0.65) and incident myocardial infarction (HR 0.55; 95% CI, 0.34 to 0.89), whereas marginally significant reduction in risk of stroke was observed at 5 years and 10 years (HR at 5 years: 0.82; 95% CI, 0.67 to 1.00; p = 0.049; HR at 10 years: 0.83; 95% CI, 0.69 to 1.01; p = 0.065). The strength of the association declined over time but remained significant. Similar results were observed when all nitrogen-containing bisphosphonates (N-BPs) were analyzed together. These findings were robust in multiple sensitivity analyses. Additional studies in other population samples and randomized clinical trials may be warranted to further understand the relationship between use of various antiosteoporosis medication and risk of CVE in patients with hip fracture.