In-hospital and 1-year mortality after percutaneous coronary intervention in patients without standard modifiable risk factors: a mediation analysis from Thai PCI registry
S Kiatchoosakun, P Chichareon, C Wongwipaporn, V Senthong, P Intharathet, B Pussadhamma, W Roongsangmanoon, S Siriyotha, A Thakkinstian, N SansanayudhAbstract
Background
Standard modifiable risk factors (SMuRFs), including hypertension, hypercholesterolemia, diabetes, and smoking, contribute substantially to atherosclerosis. However, patients with SMuRF-less remain at risk of mortality after percutaneous coronary intervention (PCI). The mechanisms underlying this risk are not well understood.
Purpose
This study aimed to identify clinical pathways mediating short- and long-term mortality among SMuRF-less patients undergoing PCI.
Methods
Data from a multicenter Thai PCI registry was used including patients who underwent PCI at 39 cardiac centers between 2018-2019. Patients with prior coronary artery syndromes were excluded. Clinical data, procedural characteristics, medication use during PCI and at discharge, and outcomes (in-hospital and 1-year-death) were collected. Mediation analyses were performed using generalized structural equation modeling to assess indirect effects of SMuRF-less on death through STEMI presentation, antiplatelet therapy, procedural complications, guideline-directed medical therapy (GDMT: RAAS, beta-blocker and statins).
Results
Among 12,190 eligible patients, 684 (5.6%) were SMuRF-less. In-hospital death was significantly higher in SMuRF-less than at-least-one SMuRF (5.6% vs 3.5%). After adjusting covariates, SMuRF-less was significantly higher odds of death [OR = 1.70 (95% CI: (1.31, 2.23)]. STEMI significantly mediated this association [indirect OR = 1.33 (1.20, 1.88)], whereas mediation through clopidogrel and procedural complication was minimal. Among hospital survivors, SMuRF-less was not significantly associated with 1-year death [OR= 0.96 (0.66, 1.25)]; however, lower use of RAAS blockade [OR = 1.29 (1.16, 1.45)], beta-blocker[OR=1.05 (1.01, 1.12)] and statins [OR = 1.38 (1.10, 1.76)] significantly mediated increased 1-year-death.
Conclusion
Early mortality among SMuRF-less patients undergoing PCI is largely driven by STEMI presentation, whereas long-term risk is influence by underuse of secondary prevention therapies. Ensuring equitable GDMTs is essential to improving outcomes in this population.