Trends and Outcomes of Lower Limb Amputation in Patients With Coronary Artery Disease

Background and aim Coronary artery disease (CAD) is a leading cause of morbidity and mortality in the United States, with peripheral arterial disease (PAD) and lower limb (LL) amputation contributing to poor cardiovascular outcomes. While previous studies have identified the link between CAD and PAD-related amputations, data on short-term in-hospital outcomes remain limited. This study aimed to compare in-hospital mortality and complications between CAD patients undergoing LL amputation and those without it. Methods We conducted a retrospective cohort study using the Nationwide Inpatient Sample (NIS) from 2016 to 2021, identifying CAD patients with and without LL amputation via International Classification of Diseases, 10th Revision (ICD-10) codes. Propensity score matching (PSM) was performed using a 1:1 nearest-neighbor algorithm to minimize selection bias, adjusting for demographics, comorbidities, and hospital characteristics. The primary outcome was in-hospital all-cause mortality, while secondary outcomes included acute heart failure, cardiogenic shock, acute kidney injury (AKI), major adverse cardiac and cerebrovascular events (MACCE), and healthcare resource utilization. Results A total of 31,379,939 CAD patients were identified, with 119,320 (0.4%) undergoing LL amputation. After propensity score matching (PSM), 23,261 patients were included in each group. The LL amputation cohort exhibited significantly higher in-hospital mortality (5.5% vs. 3.3%, p<0.001), cardiac arrest (2.3% vs. 1.4%, p<0.001), acute kidney injury (AKI) (29.3% vs. 26.8%, p<0.001), and acute limb ischemia (5.2% vs. 0.4%, p<0.001). Conversely, CAD patients without amputation had higher rates of acute heart failure (18.3% vs. 10.7%, p<0.001), major adverse cardiac and cerebrovascular events (MACCE) (22.5% vs. 12.2%, p<0.001), and percutaneous coronary intervention (6.7% vs. 0.9%, p<0.001). The length of stay and total hospital charges were significantly higher in the amputation group (10 days vs. four days; $26,590 vs. $11,686, p<0.001). Conclusion Lower limb amputation in CAD patients is associated with increased in-hospital mortality, cardiac complications, and healthcare resource utilization. These findings underscore the need for early intervention strategies targeting PAD progression and comprehensive perioperative cardiovascular risk management in amputees. Future research should focus on optimizing revascularization approaches, rehabilitation programs, and tailored preventive measures to improve outcomes in this high-risk population.