Introduction: Patients with ST-elevation myocardial infarction (MI) (STEMI) who present with cardiogenic shock (CS) still have unfavorable prognosis. We evaluated the clinical outcomes of patients with STEMI and CS according to the right coronary artery (RCA) and non-RCA involvement as culprit lesion.
Methods: Among 28312 acute MI patients in a nationwide, prospective, multicenter registry, 1308 STEMI patients with CS who underwent primary percutaneous coronary intervention (PCI) had the RCA involvement as culprit lesion of 772 patients (59.0%) and the non-RCA involvement of 536 patients (41.0%). All-cause death and major adverse cardiac events (MACE; all-cause death, MI, or revascularization) were compared in the entire and propensity score (PS)-matched cohorts.
Results: During a median 322 days of follow-up, MACE occurred in 343 patients (26.2%), with a significantly lower incidence in the RCA group than non-RCA group (entire cohort: 19.6% vs. 35.8%, p<0.001; PS-matched cohort: n=652, 12.6% vs. 25.2%, p<0.001). All-cause death occurred in 206 patients, with a significantly lower incidence in the RCA group than non-RCA group (entire cohort: 14.1% vs. 31.0%, p=0.043; PS-matched cohort: 9.2% vs. 19.0%, p=0.002). Kaplan-Meier estimates noted that the RCA group, compared to the non-RCA group, had significantly higher MACE-free survival rates (entire cohort: 80.4% vs. 64.2%, log-rank p<0.001; PS-matched cohort: 87.4% vs. 74.8%, log-rank p<0.001) and all-cause death-free survival rates (entire cohort: 85.9% vs. 69.0%, log-rank p<0.001; PS-matched cohort: 91.8% vs. 81.0%, log-rank p<0.001). Cox proportional analysis showed that the RCA involvement as culprit lesion was predictive for lower risk of MACE (entire cohort: hazard ratio [HR] 0.647, 95% confidence interval [CI] 0.438-0.956, p=0.029; PS-matched cohort: HR 0.451, 95% CI 0.217-0.937, p=0.033) and all-cause death (entire cohort: HR 0.403, 95% CI 0.316-0.516, p<0.001; PS-matched cohort: HR 0.394, 95% CI 0.251-0.620, p<0.001), significantly.
Conclusions: The RCA involvement as culprit lesion, compared to the non-RCA involvement, was associated with the improved clinical outcomes in patients with STEMI and CS who were treated with primary PCI.