Evaluating perioperative risks in total knee arthroplasty patients with normal preoperative cardiac stress tests

Introduction: While it is generally accepted that most patients undergoing joint replacement do not require a cardiac stress test, individuals with existing or potential cardiac conditions may be at an increased risk of perioperative complications following primary total knee arthroplasty (TKA). This study aims to analyze the immediate postoperative outcomes of patients who underwent primary TKA, comparing those who had a cardiac stress test with no abnormal results and subsequent cardiac interventions to those who did not undergo a stress test. Materials and methods: This retrospective cohort study utilized the TriNetX Research Network. The first cohort included patients who underwent a stress test within one year prior to their TKA, had no abnormal results, and did not undergo cardiac catheterization within two weeks post-stress test (Normal Stress Test). The second cohort consisted of patients who did not have a stress test in the year preceding their TKA (No Stress Test). The study analyzed data collected between January 1, 2003, and January 1, 2024. To control for confounding variables, propensity score matching was employed. P < 0.01 was considered significant. Results: A total of 13,881 patients successfully matched in each cohort. Within 30 days following TKA, patients in the Normal Stress Test cohort exhibited a significantly elevated risk of several complications: Transfusion (RR: 1.702), Myocardial Infarction (MI) (RR: 1.908), Acute Renal Failure (ARF) (RR: 1.504), Acute Posthemorrhagic Anemia (RR: 1.245), Wound Dehiscence (RR: 1.549), and Pneumonia (RR: 2.051). These results were consistent at the 90-day follow-up. Notably, the risk of death was only elevated before propensity score matching (RR: 2.115). Conclusion: Our findings suggest that the underlying conditions prompting the use of a cardiac stress test, including congestive heart failure and renal insufficiency, may themselves be indicative of a higher overall perioperative risk, regardless of the stress test results.