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

Comparison of clinical outcomes between proximal and non-proximal right coronary artery occlusion in patients with inferior ST-segment elevation myocardial infarction

BACKGROUND

The clinical outcomes of ST-segment elevation myocardial infarction (STEMI) due to the occlusion of left coronary artery are worse in patients with proximal occlusion than in those with non-proximal occlusion. However, there are few reports that focus on the comparison of clinical outcomes in patients with STEMI between proximal and non-proximal right coronary artery (RCA) occlusions.

METHODS

We included 356 patients with STEMI whose infarct-related artery is RCA and divided them into the proximal group (n = 129) and the non-proximal group (n = 227). We defined segment 1 of RCA as proximal, and segments 2, 3, and 4 as non-proximal according to the reporting system of the American Heart Association. The primary endpoint was major cardiovascular events (MACE), which was defined as the composite of all-cause death, non-fatal myocardial infarction, readmission for heart failure, and ischemia-driven target vessel revascularization.

RESULTS

Incidence of shock at admission, requirement for catecholamine during percutaneous coronary intervention (PCI), or mechanical support during PCI tended to be higher in the proximal group (42.6 %) than in the non-proximal group (33.5 %) (p = 0.088). Although the incidence of right ventricular infarction tended to be higher in the proximal group (17.8 %) than in the non-proximal group (10.6 %) without reaching statistical significance (p = 0.072), the incidence of in-hospital death was similar between the 2 groups (1.6 % versus 1.8 %, p = 1.000). The MACE-free survival curves were not different between the 2 groups (p = 0.400). Multivariate Cox hazard analysis revealed that proximal RCA occlusion was not associated with MACE (HR 1.095, 95%CI 0.691-1.737, p = 0.699).

CONCLUSIONS

Although the acute phase conditions such as shock or right ventricular infarction tended to be more severe in patients with proximal occlusion, overall clinical outcomes including long-term outcomes were comparable between the proximal and distal RCA occlusions. Furthermore, multivariate analysis showed that the proximal RCA occlusion was not associated with MACE after hospital discharge.

Factors associated with temporary pacing insertion in patients with inferior ST-segment elevation myocardial infarction

Background

High-degree atrioventricular block (HAVB) is a prognostic factor for survival in patients with inferior ST-segment elevation myocardial infarction (STEMI). However, there is little information about factors associated with temporary pacing (TP). The aim of this study was to find factors associated with TP in patients with inferior STEMI.

Methods

We included 232 inferior STEMI patients, and divided those into the TP group (n = 46) and the non-TP group (n = 186). Factors associated with TP were retrospectively investigated using multivariate logistic regression model.

Results

The incidence of right ventricular (RV) infarction was significantly higher in the TP group (19.6%) than in the non-TP group (7.5%) (p = 0.024), but the incidence of in-hospital death was similar between the 2 groups (4.3% vs. 4.8%, p = 1.000). Long-term major adverse cardiovascular events (MACE), which were defined as a composite of all-cause death, non-fatal myocardial infarction (MI), target vessel revascularization (TVR) and readmission for heart failure, were not different between the 2 groups (p = 0.100). In the multivariate logistic regression analysis, statin at admission [odds ratio (OR) 0.230, 95% confidence interval (CI) 0.062–0.860, p = 0.029], HAVB at admission (OR 9.950, 95% CI 4.099–24.152, p<0.001), and TIMI-thrombus grade ≥3 (OR 10.762, 95% CI 1.385–83.635, p = 0.023) were significantly associated with TP.

Conclusion

Statin at admission, HAVB at admission, and TIMI-thrombus grade ≥3 were associated with TP in patients with inferior STEMI. Although the patients with TP had the higher incidence of RV infarction, the incidence of in-hospital death and long-term MACE was not different between patients with TP and those without.