Peripheral microvascular function and long-term cardiovascular outcomes after percutaneous coronary intervention in patients with obstructive coronary artery disease.

Background: Despite advances in percutaneous coronary intervention (PCI), patients with obstructive coronary artery disease (CAD) continue to experience recurrent ischemic symptoms and adverse cardiovascular events. Skin post-occlusive reactive hyperemia (PORH) is a noninvasive measure of systemic microvascular function that may add prognostic information beyond epicardial coronary anatomy, but its relation to long-term cardiovascular outcomes after PCI has not been well defined. Methods: We performed a retrospective analysis of a prospectively established CAD registry that included 197 patients with obstructive CAD who underwent PCI and baseline assessment of the skin PORH response. Long-term composite cardiovascular outcomes were evaluated over follow-up of up to 5 years using Kaplan-Meier methods and Cox proportional hazards regression, with propensity score matching used as a sensitivity analysis. Results: The median age of the cohort was 66 years, and 84.8% of patients were male. Compared with those in the higher PORH group, patients with a lower PORH index had more cardiometabolic comorbidities and experienced significantly higher rates of long-term composite cardiovascular events. In multivariable Cox analysis, a higher PORH index was independently associated with a lower risk of composite cardiovascular events (adjusted hazard ratio, 0.422; 95% confidence interval, 0.198-0.898), and this inverse association was preserved in the propensity score-matched cohort. Conclusions: In patients with obstructive CAD undergoing PCI, impaired skin PORH was independently associated with an increased risk of long-term composite cardiovascular events. These findings support a potential role for skin microvascular assessment in cardiovascular risk stratification, and warrant confirmation in larger prospective studies.