Abstract
Purpose :
Despite the growing body of evidence that implicates endothelial dysfunction as a key mediator in the development several cardiovascular diseases, little is known about local retinal vascular changes in patients with cardiovascular disease, such as heart failure with preserved ejection fraction (HFpEF), at baseline and during exercise. This study investigates the impact of a 6-minute walking test on retinal microvascular density in HFpEF patients using OCT Angiography.
Methods :
This is an IRB approved prospective cohort study. 5 HFpEF patients (8 eyes, 2 women and 3 men) were imaged with SD-OCTA (Optovue Avanti XR). 3×3 mm and 6×6 mm OCT angiograms of the macula were obtained before and after a 6-minute walking test (6MWT) to assess dynamic changes in vessel density (VD) in the superficial and deep capillary plexus vessel density (SCP, DCP, respectively). Parafoveal VD from 3x3 mm OCTA and perifoveal VD from the 6x6 mm OCTA were recorded. Cardiovascular response (blood pressure, heart rate), distance walked during the 6MWT were assessed before and after exercise. VD analysis was performed using automated AngioAnalytics software. The post-intervention OCTAs were obtained within 10 minutes of completion of 6MWT. The 6MWT is a standardized cardiopulmonary test that measures functional exercise capacity and reflects ability to perform everyday physical activities. The level p < 0.05 was considered statistically significant.
Results :
The median patient age was 71 [64 – 74], median 6MWT distance was 293 meters [249 – 385], and median LVEF was 55 [55 – 61]. Baseline VD in the SCP and DCP in HFpEF patients was generally lower than published normative metrics in similarly aged, healthy patients. (Table 1) Heart rate increased significantly after the 6MWT (p = 0.03) while SBP (p = 0.15) and DBP (p = 0.75) did not change significantly. VD in the SCP and DCP did not change significantly after the 6MWT.
Conclusions :
Quantitative and dynamic changes in the retinal microvasculature might be useful for examining pathophysiology and functional status in HFpEF. This study finds no significant changes in retinal vessel density after a 6MWT in HFpEF patients, suggesting steady perfusion at the level of the retina and maintained autoregulatory mechanisms in this population. Importantly, HFpEF patients were found to have lower baseline VD metrics compared to similarly aged, healthy patients.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.