Risk factors for adverse cardiac events in hip fracture patients: an analysis of NSQIP data

Purpose Cardiovascular complications constitute morbidity and mortality for hip fracture patients. Relatively little data exist exploring risk factors for post-operative complications. Using the American College of Surgeons National Surgical Quality Improvement (ACS-NSQIP) database, we identified significant risk factors associated with adverse cardiac events in hip fracture patients and provide recommendations for practising orthopaedists. Methods A cohort of 27,441 patients with hip fractures from 2006 to 2013 was identified using Current Procedural Terminology codes. Cardiac complications were defined as cardiac arrests or myocardial infarctions occurring within 30 days after surgery. Bivariate analysis was run on over 30 patient and surgical factors to determine significant associations with cardiac events. Multivariate logistical analysis was then performed to determine risk factors most predictive for cardiac events. Results Of the 27,441 hip fracture patients, 594 (2.2 %) had cardiac complications within 30 days post-operatively. There was no significant association with respect to type of hip fracture surgery and adverse cardiac event rates (p = 0.545). After multivariate analysis, dialysis use (OR: 2.22, p = 0.026), and histories of peripheral vascular disease (OR: 2.11, p = 0.016), stroke (OR: 1.83, p = 0.009), COPD (OR: 1.69, p = 0.014), and cardiac disease (OR: 1.55, p = 0.017) were significantly predictive of post-operative cardiac events in all hip fracture patients. Conclusion Orthopaedic trauma surgeons should be aware of cardiac disease history and atherosclerotic conditions (PVD, stroke) in risk stratifying patients to prevent cardiac complications. Our recommendations to reduce cardiac events include simple pre-operative lab-work to full-fledged cardiac work-up and referrals to specific medicine disciplines based on the specific risk factors present.