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Updated: Sep 17, 2025
Intravital Video Microscopy Measurements of Retinal Blood Flow in Mice
Published on: December 26, 2013
Myocardial Blood Flow and the Retinal Microvasculature Across the Spectrum From Normal to Failing Hearts
Jia Liu1, Chang Chen1, Zhongping Yu1
1Department of Cardiology, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, China.
Insights
Myocardial blood flow and retinal microvasculature are linked to heart function. Reduced flow and smaller retinal vessel ratios are associated with impaired left ventricular function, with NT-proBNP mediating nearly 30% of this effect.
Area of Science:
- Cardiology
- Microvascular function
- Heart failure research
Background:
- Myocardial microcirculation deficiency contributes to heart failure (HF) pathogenesis.
- The interplay between myocardial blood flow (MBF), retinal microvasculature, and left ventricular (LV) function requires further elucidation.
- NT-proBNP is a key biomarker in HF, potentially mediating vascular effects.
Purpose of the Study:
- To investigate the association of myocardial blood flow (MBF) and retinal microvasculature (arteriole-to-venule ratio, AVR) with left ventricular (LV) function.
- To explore the direct and indirect contributions of MBF and AVR to LV function, including mediation via NT-proBNP.
- To assess these associations across different stages of cardiovascular health, from healthy controls to compensated heart failure.
Main Methods:
- Multivariable regression models were used to analyze data from healthy controls (n=48), cardiovascular risk factor patients (n=49), and compensated HF patients (n=52).
- Key parameters assessed included LV diastolic filling pressure (E/e'), LV ejection fraction (LVEF), global longitudinal strain (GLS), MBF, and AVR.
- Mediation analysis was performed to evaluate the indirect effects of MBF and AVR on LV function through NT-proBNP.
Main Results:
- Compensated HF patients exhibited lower MBF and smaller AVR compared to healthy controls.
- A smaller AVR was significantly associated with higher E/e', lower LVEF, and lower GLS across all participants.
- Reductions in MBF were directly associated with worsening LV diastolic pressure and systolic function (lower LVEF and GLS).
- NT-proBNP significantly mediated the relationship between MBF and LV function, and between AVR and GLS, accounting for at least 29% of the effect.
Conclusions:
- Myocardial blood flow and retinal microvasculature are significantly associated with left ventricular function.
- These microvascular parameters appear to counterbalance impaired LV function in compensated HF.
- NT-proBNP plays a crucial role, mediating approximately 30% of the maintenance of LV function through its vasodilating and natriuretic actions.
Abstract:
Deficiency of the myocardial microcirculation plays a role in the pathogenesis of heart failure (HF). We aimed to investigate the association of myocardial blood flow (MBF) and the retinal microvasculature with left ventricular (LV) function and its potential mediators. In healthy controls (HCs; n = 48), patients with cardiovascular risk factors (CVRF; n = 49) and patients with compensated HF (CHF; n = 52), we assessed LV diastolic filling pressure (E/e'), LV ejection fraction (LVEF), and global longitudinal strain (GLS) associated with MBF and the retinal arteriole-to-venule ratio (AVR), using multivariable regression models, while considering their direct contributions to LV function and the indirect contributions running via NT-proBNP. Compared with HC, CHF had lower MBF and smaller AVR (p ≤ 0.002). In all participants, smaller AVR was associated with higher E/e', lower LVEF, and lower GLS (p ≤ 0.010). Per 1 dB × dB/s MBF reduction, E/e' increased by 0.09, whereas LVEF and GLS decreased by 0.46% and 0.14%, respectively (p < 0.001). The indirect contributions running via NT-proBNP were all significant (p < 0.001) for MBF and for AVR related to GLS (p = 0.044) with mediation proportions of ≥29%. Across subgroups, these associations were directionally similar but lost significance given the lower sample size. Furthermore, across the spectrum of LV function, estimates of the associations of MBF with E/e' and AVR with GLS showed a decreasing versus increasing trend (p ≤ 0.034). MBF and retinal microvasculature were associated with LV function and counterbalance the impaired LV function in CHF. NT-proBNP, the natural vasodilating and natriuretic hormone, contributes close to 30% of the maintenance of LV function.
