The effect of interarm blood pressure difference on coronary collateral flow in patients with ST-segment elevation myocardial infarction who had undergone primary percutaneous coronary intervention.

Objective: In patients with acute myocardial infarction, coronary collateral circulation (CCC) is associated with reduced infarct size, preserved cardiac function, and decreased mortality. An interarm blood pressure difference (IABPD) is shown to be independently associated with cardiovascular and all-cause of mortality. We aimed to determine the effect of IABPD on coronary collateral flow in patients with ST-segment elevation myocardial infarction (STEMI) who had undergone primary percutaneous coronary intervention (p-PCI).

Patients And Methods: We prospectively investigated 1,348 consecutive patients who were hospitalized for STEMI and underwent p-PCI. The Rentrop classification was used to assess CCC. According to this classification, we defined Rentrop 0 and 1 as poor CCC, and Rentrop 2 and 3 as good CCC. A 10 mm Hg difference is considered the upper limit of IABPD.

Results: Patients were divided into two groups according to the collateral circulation, 325 patients (24%) had good collateral, while 1,023 patients (76%) had poor collateral. IABPD was significantly higher in the poor collateral group (57 patients, 5.6%) than in the good collateral group (9 patients, 2.8%) (p=0.04). Pre-infarction angina and IABPD were identified as independent predictors of poor collateral (OR: 0.516, 95% CI 0.370-0.631, p=0.007; OR: 3.681, 95% CI: 1.773-7.461, p=0.01, respectively) in multivariate analysis.

Conclusions: The IABPD was shown as an independent predictor of poor collateral circulation in patients with STEMI who underwent p-PC.