Coronary Flow Reserve in the Remote Myocardium Predicts Left Ventricular Remodeling Following Acute Myocardial Infarction

Abstract

PurposeCoronary flow reserve (CFR) in the non-infarcted myocardium is often impaired following acute myocardial infarction (AMI). However, the clinical significance of CFR in the non-infarcted myocardium is not fully understood. The objective of the present study was to assess whether a relationship exists between CFR and left ventricular remodeling following AMI.Materials and MethodsWe enrolled 18 consecutive patients undergoing coronary intervention. Heart function was analyzed using real-time myocardial contrast echocardiography at one week and six months after coronary angioplasty. Ten subjects were enrolled as the control group and were examined using the same method at the same time to assess CFR. Cardiac troponin I (cTnI) levels were routinely analyzed to estimate peak concentration.ResultsCFR was 1.55±0.11 in the infarcted zone and 2.05±0.31 in the remote zone (p<0.01) at one week following AMI. According to CFR values in the remote zone, all patients were divided into two groups: Group I (CFR <2.05) and Group II (CFR >2.05). The levels of cTnI were higher in Group I compared to Group II on admission (36.40 vs. 21.38, p<0.05). Furthermore, left ventricular end diastolic volume was higher in Group I compared to Group II at six months following coronary angioplasty.ConclusionMicrovascular dysfunction is commonly observed in the remote myocardium. The CFR value accurately predicts adverse ventricular remodeling following AMI.

MR findings of microvascular perfusion in infarcted and remote myocardium early after successful primary PCI

“…The remote myocardium in patients with STEMI has also been evaluated in a series of studies applying other methods than CMR. In a recent study in patients with acute myocardial infarction, Cheng et al [ 45 ] showed a correlation between impaired coronary flow reserve measured by contrast enhanced echocardiography in the non-infarcted myocardium and left ventricular remodeling and function. Decreased microvascular density and activation of the renin-angiotensin system were proposed as underlying mechanism [ 45 , 46 ].…”

“…In a recent study in patients with acute myocardial infarction, Cheng et al [ 45 ] showed a correlation between impaired coronary flow reserve measured by contrast enhanced echocardiography in the non-infarcted myocardium and left ventricular remodeling and function. Decreased microvascular density and activation of the renin-angiotensin system were proposed as underlying mechanism [ 45 , 46 ]. Another theory implies that in the situation of an acute infarction the remote myocardium initiates compensatory metabolic reactions [ 47 ].…”

Physiological Lesion Assessment in STEMI and Other Acute Coronary Syndromes

“…Cheng et al evaluated 18 patients with acute MI and found that the CFR in the remote region (i.e., the region supplied by the non-infarct artery) was linked to CFR in the infarcted region and correlated with infarct size and severity. Even after successful PCI, the CFR in the myocardium supplied by the infarct-related artery was lower than normal [18]. A CFR > 2.0 is generally considered normal.…”

An Experimental Series Investigating the Effects of Hyperinsulinemic Euglycemia on Myocardial Blood Flow Reserve in Healthy Individuals and on Myocardial Perfusion Defect Size following ST-Segment Elevation Myocardial Infarction

“…Analysis was then repeated to regionalise MBF into infarct-territory MBF and remote MBF by separate analysis of infarct and remote myocardial segments 19 . Ischemic segments were identified as myocardial segments supplied by the infarct-related artery and showing hypokinesia at initial transthoracic echocardiography conducted on presentation.…”