Insights Into Myocardial Oxygenation and Cardiovascular Magnetic Resonance Tissue Biomarkers in Heart Failure With Preserved Ejection Fraction

Abstract

Background: The pathophysiology of heart failure with preserved ejection fraction is not well understood, but evidence strongly suggests involvement of microvascular dysfunction. We studied the myocardial oxygenation reserve as a direct marker of coronary vascular function and its relation to myocardial deformation and tissue characteristics by cardiovascular magnetic resonance (CMR). Methods: In a dual-center case-control study, patients with heart failure and preserved ejection fraction (>50%) and healthy controls older than 50 years underwent quantitative CMR for ventricular volumes and functional assessment with feature tracking, as well as tissue characterization (T1, T2, extracellular volume). Coronary vascular function was measured by oxygenation-sensitive (OS)–CMR of the myocardial oxygenation response to a vasoactive breathing maneuver. Results: Twenty-nine patients completed the CMR exam. Compared with cutoffs derived from 12 control subjects, circumferential peak strain was attenuated in 97% of patients. Native T1 was elevated in 93%, extracellular volume was elevated in 83%. Sixty-six percent of patients revealed either regional or global myocardial edema, defined by an increased myocardial T2. An attenuated global myocardial oxygenation reserve (<4.4%) was observed in 96% of the patients (1.7±3.9% versus 9.1±5.3% in controls, P <0.001). This was correlated with septal wall thickness (r=−0.54, P =0.003), edema (myocardial T2; β=−0.26% oxygenation-sensitive/ms [95% CI, −0.49 to −0.03], P =0.029), and reduced diastolic strain rate (β=1.50% oxygenation-sensitive/s -1 [95% CI, 0.06–2.90], P =0.042). Conclusions: In patients with clinical heart failure with preserved ejection fraction, vascular dysfunction as measured by an attenuated myocardial oxygenation reserve is associated with myocardial edema, a thicker septum, and diastolic dysfunction. A quantitative comprehensive CMR exam including oxygenation-sensitive–CMR allows for comprehensive imaging-based phenotyping of heart failure with preserved ejection fraction.

Endothelial Dysfunction in Heart Failure With Preserved Ejection Fraction: What are the Experimental Proofs?

“…Even NOS3 activity or endothelial-dependent vasodilation, the most studies feature of endothelial dysfunction has been evaluated in only 8 of the 14 models. Endothelial permeability which is suggested to be present in 66% of patients with HFpEF (Fischer et al, 2022) has been quantified in only one model.…”

“…T2 mapping suggested 66% of patients actually have myocardial edema. In Fischer et al study, attenuated myocardial oxygenation reserve was associated with myocardial edema and diastolic dysfunction (Fischer et al, 2022).…”

“…Notably, patients showing endothelium-independent microvascular dysfunction had worse diastolic dysfunction (E/e') and higher overall mortality. Anyways, cardiac magnetic resonance imaging has revealed that 96% of patients with HFpEF demonstrate at least a regional oxygenation impairment (Fischer et al, 2022).…”

“…Cardiac magnetic resonance imaging showed that 83% of patients with HFpEF patients display increased extracellular volume (T1 mapping) reflecting either high water content and/or increased fibrotic load (Löffler et al, 2019;Fischer et al, 2022). T2 mapping suggested 66% of patients actually have myocardial edema.…”

Combined Analysis of Myocardial Deformation and Oxygenation Detects Inducible Ischemia Unmasked by Breathing Maneuvers in Chronic Coronary Syndrome

“…In patients with myocardial infarction, resting strain has been reported to be related to the extent of LGE ( 39 ). However, in a heart failure cohort without infarct patients, there was no association of resting strain with LGE, rather a correlation to T2 mapping and the OS response with apnea ( 50 ). This will have to be investigated in the future to determine if infarcted territory impacts both resting strain, and the dynamic response to a stimulus.…”