Hypertensive retinopathy predicts long term incident cardiovascular and cerebrovascular events: A systematic review and meta analysis

Background: Hypertension may lead to target organ damages associated with both microvascular and macrovascular complications. Retinal photography is a simple non-invasive tool that may detect retinal microvascular abnormalities in hypertensive patients, which may indicate a higher risk of cardiovascular (CVD) and cerebrovascular diseases (CeVD)

Objective: To investigate the association between Hypertensive Retinopathy (HR) with adverse CVD and CeVD events.

Methods: Systematic database search through Pubmed and Embase was conducted on 11th December 2023. Eligibility criteria were (1) Longitudinal studies; (2) Conducted in hypertensive patients; (3) Evaluated the association between the presence or severity of HR with occurrence of adverse cardiovascular or cerebrovascular events; (4) Specifically assessed HR or conducted a separate analysis according to HR status of the patients. Random-effects model was employed to calculate pooled Risk Ratios (RR) with corresponding 95% confidence interval (95% CI) for each endpoint. Statistical analyses was performed using Review Manager version 5.4.

Results: Out of 1,224 screened unique records, 8 cohort studies ( 25,241 hypertensive patients) were included. Follow-up period ranged 4 months–20 years. The Keith-Wagener-Barker classification system was the most common method to stratify the severity of HR. For CVD events, presence of HR was associated with a two-fold higher risk of developing composite CVD events (RR 1.99 [95% CI 1.63–2.42]; I2 = 62%) coronary heart disease (RR 1.93 [1.72–2.17]; I2=0%), and almost a three-fold risk of composite all-cause mortality and myocardial infarction (RR 2.81 [1.66–4.76]; I2=0%). Patients with HR also had a higher risk of ischemic stroke (RR 1.88 [1.42–2.48]; I2=77%) and composite CeVD events (RR 1.44 [1.22–1.70]; I2=0%). The association remained significant in mild vs no HR for ischemic stroke (RR 1.65 [1.19–2.30]; I2=81%) and composite CeVD events (RR 1.42 [1.16–1.75]; I2=28%). Moderate-severe HR was associated with a greater risk of ischemic stroke (RR 1.95 [1.43–2.64]; I2=0%) and composite CeVD events (RR 2.13 [1.63–2.80]; I2=0%) compared to mild HR.

Conclusion: HR is significantly associated with long-term risk of developing CVD and CeVD. A more intensive preventive strategy may be needed for these patients.

Keywords: Hypertensive retinopathy, cardiovascular events, cerebrovascular events, meta analysis