Comparing the clinical and prognostic impact of proximal versus nonproximal lesions in dominant right coronary artery ST-elevation myocardial infarction

Objective: To evaluate the prognostic significance of culprit lesion location in dominant right coronary artery (RCA) ST-elevation myocardial infarction (STEMI). Background: In RCA STEMI, proximal culprit lesions have been shown to have higher rates of acute complications such as bradycardia and cardiogenic shock (CS) but data on mortality is limited. Methods: We retrospectively identified and analyzed data from consecutive patients with a dominant RCA STEMI who underwent either primary or rescue percutaneous coronary intervention (PCI) between January 2003 and December 2016. We compared the rates of sustained ventricular tachycardia (VT), CS, intra-aortic balloon pump (IABP), temporary cardiac pacing (TCP) and death between culprit lesions located proximal and distal to the origin of the last right ventricular (RV) marginal artery >1 mm in diameter. Results: The 939 patients were included; 599 (63.7%) had a proximal lesion and 340 (36.3%) had a nonproximal lesion. The 801 (85.3%) underwent primary PCI and 138 (14.7%) underwent rescue PCI. There was no difference in first medical contact to balloon or fibrinolysis times between the groups; p =.98 and.71. There was no significant difference in the rate of sustained VT (3.0%vs. 3.2%, p =.85) but proximal lesions were more likely to develop CS (10.9%vs. 5.8%, p =.01), require IABP (7.3%vs.2.9%, p <.01) and TCP (6.3%vs. 2.6%, p =.01). Thirty-day mortality was higher for proximal lesions (5.0%vs. 0.9%, p <.01) particularly for those with CS (35.3%vs. 10.0%, p =.05). Conclusion: Culprit lesions located proximal to the origin of the last RV marginal artery had a higher rate of acute complications such as CS and mortality.