Abstract 4329: Human Atrial Natriuretic Peptide Preserved Infract-related Myocardial Blood Flow Quantified by Perfusion MRI in Patients With Acute Myocardial Infarction
Background: Human atrial natriuretic peptide (ANP) inhibits reperfusion injury, reduces infarct size and prevents left ventricular (LV) remodeling in patients with acute myocardial infarction (AMI). However, the beneficial effects of ANP infusion on myocardial blood flow (MBF) in the infracted area have not been well evaluated in patients with AMI. The purpose of this study was to evaluate the effects of ANP infusion during the acute phase of AMI on MBF using quantitative assessment of regional MBF.
Methods: Thirty-four consecutive patients with anteroseptal AMI who underwent primary angioplasty were divided into two subgroups; ANP group (n=18, 65±13 y.o., male 89%) and control group (n=16, 60±11y.o., male 94%,). ANP with 0.025ug/kg/min was intravenously administered for 72hrs in ANP group. All patients underwent cine MRI, rest perfusion MRI and LGE MRI within 10 days (4.5±2.2 days) after onset of MI, and regional MBF (ml/min/g) was quantified by using a Patlak analysis in 16 LV myocardial segments. Myocardial perfusion (MP) ratio was calculated from quantitative perfusion MRI as infract-related MBF/non infract-related MBF.
Results: MI was observed on LGE MRI in all patients and prevalence of microvascular obstruction was slightly higher in control group than ANP group. (63% v.s.44%) LV end diastolic volume was siginificantly larger in control group(156±43 v.s. 133±28 ml P<0.05). The MP ratio in ANP group was significantly higher than that in control group (0.55±0.23 v.s. 0.43±0.13 p<0.05)
Conclusion: Intravenous administration of ANP is useful in preserving MBF in infarct area, suggesting the contribution of ANP to the prevention of LV remodeling in patients with AMI.