Objective Patients with acute myocardial infarction (AMI) often have peripheral artery disease (PAD). It is well known that the long-term clinical outcomes of AMI are worse in patients with a low ankle-brachial index (ABI) than in patients with a preserved ABI. Unlike ABI, the association between the inter-arm blood pressure difference (IABPD) and clinical outcomes in patients with AMI has not yet been established. This retrospective study examined whether or not the IABPD is associated with long-term clinical outcomes in patients with AMI. Methods We included 979 patients with AMI and divided them into a high-IABPD group (IABPD ≥10 mmHg, n=31) and a low-IABPD group (IABPD <10 mmHg, n=948) according to the IABPD measured during hospitalization for AMI. The primary endpoint was the all-cause mortality rate. Results During a median follow-up duration of 694 days (Q1, 296 days; Q3, 1,281 days), 82 all-cause deaths were observed. Kaplan-Meier curves showed that all-cause death was more frequently observed in the high-IABPD group than in the low-IABPD group (p<0.001). A multivariate Cox hazard analysis revealed that a high IABPD was significantly associated with all-cause death (hazard ratio 2.061, 95% confidence interval 1.012-4.197, p=0.046) after controlling for multiple confounding factors. Conclusion A high IABPD was significantly associated with long-term all-cause mortality in patients with AMI. Our results suggest the usefulness of the IABPD as a prognostic marker for patients with AMI.
Keywords: acute myocardial infarction; all-cause death; ankle brachial index; clinical outcomes; inter arm blood pressure difference.