Risks and adverse clinical outcomes of peripheral arterial disease in patients with stable coronary artery disease after percutaneous coronary intervention

Background ​ ​ While peripheral artery disease (PAD) is an established risk factor for long-term mortality in stable coronary artery disease (CAD) patients following percutaneous coronary intervention (PCI), its predictors and impact on a broader range of clinical outcomes require further investigation.​ ​ Methods ​ ​ This study enrolled 204 consecutive patients with newly diagnosed stable CAD undergoing PCI at Shinonoi General Hospital between October 2014 and October 2017. The association between PAD and 4-year outcomes—including all-cause death (ACD), the composite of ACD, non-fatal myocardial infarction (MI), and stroke (ACD-MI-Stroke), the composite of cardiac death (CD), non-fatal MI, and stroke (CD-MI-Stroke), and stroke alone—was assessed using inverse probability of treatment weighting (IPTW) and adjusted Kaplan-Meier curves.​ ​ Results ​ ​ Multivariable analysis identified diabetes mellitus (DM), dyslipidemia (DLP), old cerebral infarction (OCI), coronary ostial lesions, and high triglycerides (TG) as independent predictors of PAD. For the ACD-MI-Stroke endpoint, IPTW analysis demonstrated that PAD was consistently associated with a significant, approximately threefold increased risk (hazard ratio [HR]: 3.0-3.2), with narrow confidence intervals and sustained significance (p ≤ 0.008). Although the association between PAD and ACD was of borderline significance in the unadjusted model (HR: 2.51, 95% confidence interval [CI]: 0.93–6.74), IPTW adjustment revealed a robust and consistently significant threefold risk (HR ≈ 3.0-3.1, p  ≤ 0.047). For the CD-MI-Stroke endpoint, the statistical precision of the PAD effect was attenuated with the inclusion of more covariates. Moreover, adjusted Kaplan-Meier curves consistently showed a lower survival probability for patients with PAD across all four outcomes over the 4-year follow-up.​ ​ Conclusions ​ ​ In CAD patients undergoing PCI, PAD independently and substantially increases the risk of multiple adverse outcomes, notably ACD, stroke and combinations involving them. DM, DLP, OCI, coronary ostial lesions, and elevated TG levels were identified as significant risk factors for the presence of PAD.