Navigating Total Knee Arthroplasty After Myocardial Infarction

Commentary Holle et al. performed a retrospective case-control analysis to evaluate the impact of myocardial infarction on outcomes following primary total knee arthroplasty (TKA). Using an administrative claims database, the authors found that a myocardial infarction occurring within 2 years before TKA, and particularly within 6 months, was associated with increased risks of 90-day complications and 2-year mortality. Additionally, there was a significant correlation between complication risks and the timing, type, location, and treatment of myocardial infarction. One of the study's key strengths lies in its granularity. Subgroup analyses by myocardial infarction type (type 1 compared with type 2) and electrocardiography findings (ST-elevation MI [STEMI] compared with non-ST-elevation MI [NSTEMI]) revealed that not all myocardial infarctions confer equal postoperative risks. For example, type-1 myocardial infarction and STEMI, often reflecting more extensive plaque rupture and myocardial damage, were most strongly associated with mortality. In contrast, type-2 myocardial infarction and NSTEMI were more frequently linked to noncardiac complications. Notably, type-2 myocardial infarction within 6 months was associated with a surprising increase in periprosthetic joint infection, whereas NSTEMI was linked to higher risks of pneumonia and acute kidney injury. Another important contribution is the study's subgroup analyses by revascularization (percutaneous coronary intervention), pharmacologic therapy, and infarct location (anterior compared with inferior). Not surprisingly, patients who underwent percutaneous coronary intervention had increased odds of adverse outcomes compared with those who did not, although these risks normalized after 1 year. Similarly, patients taking pharmacologic therapy after myocardial infarction had higher odds of cardiac, medical, and surgical complications than those not requiring such treatment. Both anterior and inferior myocardial infarctions were associated with higher complication rates, but only inferior myocardial infarctions were significantly correlated with increased 2-year mortality. This work has direct implications for clinical practice. First, it reinforces the importance of cardiology consultation during the preoperative evaluation of any TKA candidate who has had a recent myocardial infarction. This may include formal cardiac clearance, stress testing, or echocardiographic evaluation to assess myocardial recovery and functional reserve. Second, the findings call for patient-specific surgical timing, particularly deferring elective TKA in patients who have undergone recent percutaneous coronary intervention or extensive myocardial injury. Third, the nuanced results by myocardial infarction subtype, location, and treatment suggest that cardiac clearance guidelines should incorporate more individualized risk assessment tools. Several limitations should be noted in addition to those acknowledged by the authors. First, body mass index, a well-established risk factor for complications after TKA, was excluded from the matching criteria. Second, the study only evaluated outcomes over a 2-year period, which may not fully capture the long-term effects of myocardial infarction. This is particularly relevant, given the study finding that some of the adverse effects of prior myocardial infarction persisted through the final follow-up. Third, although patients who had undergone contralateral TKA within the preceding 2 years were excluded, the potential cumulative effects of additional surgeries that patients could have undergone were not considered. Fourth, it remains unclear whether patients in the case group were adequately treated for the myocardial infarction or had cardiac clearance preoperatively. In conclusion, Holle et al. provided a timely and clinically relevant contribution to the arthroplasty literature by highlighting the persistent and varied postoperative risks associated with myocardial infarction in patients undergoing TKA, especially myocardial infarctions occurring within 6 months prior to surgery. Although delaying TKA for 6 months may seem like a logical intervention to mitigate such risks, this approach may not serve every patient and is short-sighted. Instead, the study emphasizes the need for updated, evidence-based perioperative optimization and clearance guidelines that account for myocardial infarction subtype, timing, and treatment history. Ultimately, patient counseling, vigilance, and individualized, multidisciplinary approaches to surgical timing and cardiac optimization are key in this high-risk population.