Altitude and prognosis after PCI: A propensity score-matched analysis

Background: The impact of altitude on the prognosis of patients with coronary artery disease (CAD) after percutaneous coronary intervention (PCI) deserves further discussion and research. Methods: We conducted a post hoc analysis of a prospective observational study involving 5453 patients post-PCI, divided into medium-altitude and low-altitude groups. To control for confounding factors, propensity score matching was employed to pair patients with similar baseline characteristics between the two groups. The impact of altitude factors on patients' prognosis postPCI was examined through endpoint events over a 2-year follow-up period. Results: During the 2-year follow-up, patients at medium altitude exhibited a lower risk of MACE (including cardiovascular mortality, myocardial infarction, revascularization, and stroke) compared to those at low altitude (1196 versus 1196 patients [medium-altitude versus lowaltitude, respectively]; hazard ratio [HR], 0.781 [95 % CI, 0.629-0.969]; P = 0.025) during 2year follow-up. Even after excluding stroke, a significant difference in heart-related adverse events (HRAE) persisted between the two groups (HR, 0.794; 95 % CI, 0.636-0.991; P = 0.042). The incidences of individual MACE components were not significantly different between the two groups. Conclusions: Patients post-PCI residing at medium altitude exhibited a lower risk of 2-year MACE compared to those at low altitude. Further research is necessary to provide more robust evidence.