Abstract Body: Introduction. Adults with lower-limb loss (LLL) have increased risk of cardiovascular disease even after accounting for risk factors such as physical inactivity and comorbidity burden. Increased risk of cardiovascular mortality may be driven by structural adaptations following LLL, such as increased peripheral vascular resistance. Elevated mean arterial pressure (MAP), the steady component of blood pressure, is a clinical indicator of increased peripheral vascular resistance. Additionally, MAP >100mmHg is known to lead to cardiovascular damage. However, factors associated with elevated MAP among individuals with LLL remain unknown. We aimed to identify factors associated with elevated MAP among adults with LLL, while considering non-modifiable factors.
Hypothesis. We hypothesized that LLL-specific non-modifiable variables (e.g., amputation level) and modifiable variables (e.g., prosthesis use) would be significantly associated with elevated MAP presence.
Methods. From 2013 to 2023, community-dwelling adults, aged ≥18 years, with LLL and no history of a major adverse cardiac event, who attended a multidisciplinary LLL clinic, underwent standardized evaluations that included medical history review and blood pressure assessment. MAP was calculated using the equation: MAP = diastolic blood pressure + (0.466 × pulse pressure), with a MAP >100mmHg classified as elevated. Variables that were significantly different between-groups, i.e., MAP ≤ 100mmHg and MAP >100mmHg, were input in a forward stepwise logistic regression. Associations between modifiable factors and MAP status were evaluated after controlling for non-modifiable factors.
Results. Of 206 participants (54.5±14.1 years old; 74.3% male; 72.8% Caucasian; 81.1% unilateral LLL; 59.2% transtibial; 42.2% dysvascular etiology), n=107 (51.9%) presented with elevated MAP. MAPs >100mmHg were associated with upper extremity pain [odds ratio (OR)=2.74, 95% confidence interval (CI)=1.31-5.74, p=0.008], assistive device use (OR=2.05, 95%CI=1.12-3.74, p=0.020) and elevated pulse rate (OR=1.02, CI=1.00-1.04, p=0.045).
Conclusions. More than 50% of adults with LLL and no major adverse cardiac event history present with elevated MAP, indicating a maladaptive increase in peripheral vascular resistance. Identified factors that were significantly associated with elevated MAP may suggest subclinical cardiovascular disease and/or sympathetic overactivity, warranting closer evaluation of cardiovascular risk among adults with LLL.