Comparison of in-Hospital Outcome after Percutaneous Coronary Intervention Between Patients with Anterior Myocardial Infarction and Those With or Without Ramus Intermedius

Introduction: Primary percutaneous coronary intervention (PPCI) is used for the treatment of ST segment elevation myocardial infarction (STEMI). Anterior STEMI is associated with adverse outcomes, and it is possible that the presence of ramus intermedius (RI) would inversely affect the outcome. This research involved the evaluation of the influence of RI presence on clinical outcomes in patients with anterior STEMI and culprit lesion in the left anterior descending artery (LAD).  
Matherials and Methods: This study was conducted on 105 patients with acute anterior STEMI undergoing PPCI in Shahid Madani Hospital, Tabriz, Iran, from April 2016 to March 2018. The recorded data included the patients’ demographic and baseline data, angiographic features, presence of RI, the occurrence of heart failure (HF), cardiogenic shock, and in-hospital and one-year mortality. All data were analyzed, using SPSS software (version 23; SPSS Inc., Chicago, IL). Chi-square test, Fischer’s exact test, independent t-test, or Mann-Whitney U test were employed to compare data between the two groups. A p-value ​less than 0.05 were considered statistically significant.
Results: In this research, RI was present in 53 patients (50.5%). The RI presence was mostly detected in male patines than in their female counterparts (88.7% vs. 69.2%; P=0.01). In addition, those with RI presence had a lower rate of single-vessel disease (60.4% vs. 80.8%; P=0.01) and higher proximal LAD involvement (71.7% vs. 32.7%; P<0.001). After the intervention, ST segment decreased more than 50% and was significantly higher in patients with RI, compared to those without it (52.8% vs. 25.5%; P=0.004). Furthermore, there were no significant differences between the groups regarding cardiac enzymes, ejection fraction, HF, cardiogenic shock, and in-hospital and one-year mortality rates.
Conclusion: The presence of RI was associated with more proximal LAD lesions and less frequent single-vessel disease. However, RI did not seem to influence in-hospital and one-year outcomes.