Microvascular narrowing and BP monitoring: A single centre observational study

Does Nocturnal Blood Pressure Matter in Retinal Small Vessels? A Systematic Review and Meta-Analysis of the Literature

PURPOSE OF THE REVIEW

Τhe association between nocturnal blood pressure (BP) and alterations in the retinal microvasculature remains understudied, with few available studies to provide conflicting results. Therefore, we conducted a systematic review and meta-analysis to determine whether an association exists between retinal microvascular alterations and nocturnal BP patterns, determined by 24h ambulatory BP measurement.

RECENT FINDINGS

Our search concluded to 1002 patients (6 studies). A total of 3 studies (411 patients) were enrolled in the meta-analysis. Central retinal arteriolar equivalent found to be not different between patients with and without dipping status (mean differences [MD]: -0.01; 95% CI: -0.23 to 0.20; I²=0%; P < 0.610). Regarding central retinal venular equivalent, dippers showed significantly lower values compared to non-dippers (MD: -0.25; 95% CI: -0.47 to -0.03; I²=0%; P < 0.024). For the comparison between nighttime and daytime BP regarding the damage in small retinal vessels, we identified only 5 studies. Due to different evaluated outcomes as well as due to the heterogeneity of outcomes and different grouping of patients based on different BP cut-off values, these results couldn't be analyzed quantitatively. In summary, this is the first effort to summarize evidence on the effects of day-to-night variation of BP on the retinal small vessels. According to the findings of the present systematic review and meta-analysis, non-dipping status may be associated with retinal venular dilatation, and elevated nighttime BP with retinal arteriolar narrowing. Further studies are warranted to elucidate the impact of nocturnal BP patterns in the retinal microvasculature.

Could aortic arch calcification help in detection of hypertensive retinopathy?

OBJECTIVE

Hypertension-induced end-organ damage is one of the important determinants of morbidity and mortality in patients with hypertension. All types of hypertension-induced end-organ damages start with vascular damage. Vascular calcification is a marker of vascular damage and aortic arch calcification (AAC) is one of the easily identifiable types of vascular calcification. We hypothesized that AAC predicts retinopathy in hypertensive patients.

METHODS

Consecutive hypertensive patients without diabetes mellitus were included. Chest radiography in the posterior-anterior was used to assess the presence of AAC. All patients underwent ophthalmologic examination for retinopathy.

RESULTS

We included 495 hypertensive patients in this study. Of these, 306 (62%) had hypertensive retinopathy. Patients with hypertensive retinopathy had significantly higher prevalence of AAC as compared to the patients without hypertensive retinopathy (88% vs. 22%, P < 0.001). We found a strong and positive correlation between hypertensive retinopathy and AAC grades (r = 639, P < 0.001). Receiver operator characteristics curve analysis yielded a strong predictive ability of AAC for the presence of hypertensive retinopathy [area under curve = 0.814, 95% confidence interval (CI): 0.775-0.853, P < 0.0001]. In multivariate logistic regression analysis, presence of AAC [odds ratio (OR) 13.128; CI: 7.894-21.832] and serum glucose levels (OR 1.020; CI: 1.003-1.037) were strongly and independently associated with hypertensive retinopathy.

CONCLUSION

Presence of AAC on chest radiograph is strongly and independently associated with retinopathy in nondiabetic hypertensive patients. This simple, inexpensive and widely available tool may help in early detection of retinopathy in patients with hypertension.