The impact of acute perioperative myocardial infarction on clinical outcomes after total joint replacement

Background: Improvements in perioperative care have markedly decreased mortality after total joint replacement. Acute myocardial infarct (MI) is the most common clinically significant complication after total joint replacement (TJR) and the most common cause of 30-day mortality after TJR, which remains a concern especially in light of an older population with advanced comorbidities. In spite of this, little evidence exists in regard to its effect on TJR functional outcomes. Methods: To assess the potential impact, if any, of acute MI on the clinical outcomes of patients undergoing primary TJR, a matched cohort study of MI and non-MI patients was conducted to determine 1-year Oxford, Harris Hip and Knee Society score outcomes. Results: Of 12,739 primary TJR patients identified over a 9-year period, 0.9% (114; 95% CI, 0.75-1.1) experienced a perioperative MI. A greater proportion of MI than non-MI patients had ≥1 cardiac risk factor ( P =0.001) and an American Society for Anesthesiologist (ASA) 4 status ( P =0.037). Length of hospital stay was longer for MI cases (MI=11.5±9.8 vs. Non-MI=5.4±2.7, P <0.0001), with 70% requiring intensive care unit or cardiac care unit stays ( P <0.0001). One-year outcome scores were similar among groups ( P >0.05). One-year cardiac mortality rate was 6.1% compared to 0 non-MI deaths ( P <0.0001). Conclusions: While functional outcomes of MI after TJR are equivalent to non-MI, 1-year mortality remains high, and targeted cardiac screening and long-term monitoring for this patient population should be implemented.