Stress myocardial blood flow correlates with ventricular function and synchrony better than myocardial perfusion reserve: A Nitrogen-13 ammonia PET study

Abstract Background Reduced myocardial perfusion reserve is a well-known complication in patients with type 2 diabetes mellitus (T2DM). Furthermore, reduced myocardial perfusion reserve has been linked to the development of diastolic dysfunction, a key characteristic in diabetic cardiomyopathy. However, it is not fully explored whether a decrease in perfusion during stress or an increase in perfusion during rest is responsible for this reduction in myocardial perfusion reserve, nor is it clear what causes these changes. Purpose The purpose of this study was to examine differences in myocardial perfusion in rest and during stress in patients with T2DM compared to healthy control subjects, and to identify potential predictors for changes in perfusion during rest and stress among patients with T2DM. Methods 200 patients with T2DM and 25 healthy volunteers matched for age and sex underwent a comprehensive cardiac MRI protocol including gadolinium first-pass perfusion during rest and stress (adenosine infusion 140 mg/min–1/kg–1). Perfusion was measured on a per-segment basis based on the AHA model and averaged to calculate global perfusion index both during rest and stress. Any areas with infarctions and/or significant perfusion defects were excluded from the analysis. Backwards stepwise multiple linear regression was performed to identify predictors for perfusion changes during rest and stress in patients with T2DM. Variables with P<0.1 in a univariate analysis were included into the models. Results Patients with T2DM had significantly higher rest perfusion index (0.135±0.024 vs. 0.120±0.016; P=0.001) and significantly lower stress perfusion index (0.174±0.041 vs. 0.225±0.027; P<0.001) compared to healthy volunteers. In a multiple linear regression model among patients with T2DM female sex (P<0.001) was associated with increased rest perfusion. In a similar analysis for stress perfusion, diabetes duration (P=0.01), albuminuria (P<0.001) and the presence of ischaemic heart disease (P<0.001) were associated with reduced myocardial stress perfusion index in patients with T2DM. Conclusion In patients with T2DM reductions in myocardial perfusion reserve is caused by a combination of increased basal myocardial blood flow and a decrease in maximal blood flow during stress. Decreased stress perfusion is associated with coronary vascular disease and the diabetic complication albuminuria related to renal microvascular disease. Stress perfusion also decreased with increasing duration of T2DM. This suggest that the coronary microcirculation is gradually damaged in patients with T2DM and that the mechanism responsible is similar to that causing renal microvascular damage. Acknowledgement/Funding Local science committee of Region Zealand, Regional science committee of Region Zealand, The Danish Heart Association

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Integration Between Computed Tomography and Nuclear Medicine for Non-invasive Assessment of Coronary Anatomy and Myocardial Perfusion

European Cardiology Review ◽

10.15420/ecr.2012.5.2.15 ◽

2009 ◽

Vol 5 (2) ◽

pp. 15

Author(s):

Wanda Acampa ◽

Mario Petretta ◽

Carmela Nappi ◽

Alberto Cuocolo ◽

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...

Keyword(s):

Computed Tomography ◽

Coronary Heart Disease ◽

Blood Flow ◽

Heart Disease ◽

Myocardial Perfusion ◽

Myocardial Blood Flow ◽

Imaging Techniques ◽

Emission Computed Tomography ◽

Coronary Anatomy ◽

Non Invasive

Many non-invasive imaging techniques are available for the evaluation of patients with known or suspected coronary heart disease. Among these, computed-tomography-based techniques allow the quantification of coronary atherosclerotic calcium and non-invasive imaging of coronary arteries, whereas nuclear cardiology is the most widely used non-invasive approach for the assessment of myocardial perfusion. The available single-photon-emission computed tomography flow agents are characterised by a cardiac uptake proportional to myocardial blood flow. In addition, different positron emission tomography tracers may be used for the quantitative measurement of myocardial blood flow and coronary flow reserve. Extensive research is being performed in the development of non-invasive coronary angiography and myocardial perfusion imaging using cardiac magnetic resonance. Finally, new multimodality imaging systems have recently been developed bringing together anatomical and functional information. This article provides a description of the available non-invasive imaging techniques in the assessment of coronary anatomy and myocardial perfusion in patients with known or suspected coronary heart disease.

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Epicardial coronary stenosis severity and myocardial perfusion

Heart and Metabolism - Heart Failure in patients with Diabetes ◽

10.31887/hm.2020.81/dperera ◽

2020 ◽

pp. 12-16

Keyword(s):

Myocardial Perfusion ◽

Myocardial Ischemia ◽

Coronary Disease ◽

Myocardial Perfusion Reserve ◽

Pharmacological Intervention ◽

Fractional Flow ◽

Perfusion Reserve ◽

Flow Reserve ◽

Stenosis Severity ◽

Microvascular Resistance

Patients suspected of having epicardial coronary disease are often investigated with noninvasive myocardial ischemia tests to establish a diagnosis and guide management. However, the relationship between myocardial ischemia and coronary stenoses is affected by multiple factors, and there is marked biological variation between patients. The ischemic cascade represents the temporal sequence of pathophysiological events that occur after interruption of myocardial oxygen delivery. The earliest part of the cascade is examined via perfusion imaging, and fractional flow reserve (FFR) is a corresponding index which is specific to the coronary artery. Whereas FFR has come to be regarded a clinical reference standard against which other newer invasive and noninvasive tests are validated, the diagnostic FFR threshold for detecting ischemia was established against a combination of noninvasive ischemia tests that assessed different stages of the ischemic cascade. Moreover, the validity of invasive pressure-derived indices of stenosis severity are contingent on the assumption that pressure is proportional to flow if microvascular resistance is constant, a condition induced by pharmacological intervention or by examining specific segments of the cardiac cycle. Furthermore, myocardial perfusion reserve depends on dynamic modulation of microvascular resistance, and dysfunction of the microvasculature can lead to ischemia even in the absence of epicardial coronary disease.

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