Pain as a Driver of Myocardial Injury in Hip Fracture Patients: A Hip Fracture Accelerated Surgical Treatment and Care Track (HIP ATTACK) Trial Secondary Analysis

BACKGROUND: Pain is a common yet underaddressed issue in surgical inpatients. Inadequate pain control in patients with hip fractures can lead to adverse hemodynamic changes, potentially increasing the risk of myocardial ischemia. The authors aim to investigate whether perioperative pain is associated with the development of myocardial ischemic events in patients undergoing hip fracture surgery. METHODS: HIP fracture Accelerated surgical TreaTment And Care tracK (HIP ATTACK) was a multicenter international randomized controlled trial comparing the effects of accelerated surgical repair of hip fracture versus standard of care. The authors included patients enrolled in the HIP ATTACK trial who had at least one troponin measurement and a pain score measurement. Pain was assessed daily on hospital admission using the 0 to 10 numeric rating scale. The primary analysis included all available pain scores averaged (then categorized as mild [numeric rating scale 0 to 3], moderate [4 to 7], and severe [8 to 10] pain) before and on the day of the first troponin elevation. The primary outcome was troponin elevation from any cause, with secondary outcomes of myocardial injury (due to an ischemic etiology), myocardial infarction, and then a composite of myocardial injury and myocardial infarction. Multivariable regression models adjusting for potential confounders were used to identify an association between pain categories and outcomes. RESULTS: The authors included 2,430 (82%) from the initial HIP ATTACK cohort (n = 2,970). Forty-five percent of patients (1,098) suffered a troponin elevation from any cause. In the adjusted models, moderate (odds ratio, 3.90; 95% CI, 3.02 to 5.05) and severe pain (odds ratio, 29.24; 95% CI, 17.7 to 48.29) were associated with a troponin elevation of any cause. Similarly, moderate (odds ratio, 2.09; 95% CI, 1.71 to 2.57) and severe pain (odds ratio, 6.04, 95% CI, 4.49 to 8.12) were associated with myocardial injury, whereas only severe pain was associated with myocardial infarction (odds ratio, 2.33; 95% CI, 1.35 to 3.99). Both moderate and severe pain were associated with the composite outcome. CONCLUSIONS: Increased pain may be associated with myocardial ischemic events in the perioperative period in hip fracture patients. Future research is needed to confirm and further clarify this relationship and to determine whether analgesic interventions can reduce the risk of perioperative myocardial ischemia.