Background: The objective of this study was to compare the prevalence of quantitative markers of target organ damage, such as echocardiographically documented left ventricular hypertrophy (LVH), carotid structural changes and microalbuminuria with that of retinal abnormalities detected by qualitative funduscopic examination in a large selected population of patients with essential hypertension.
Methods: Eight hundred consecutive untreated (n = 232) and treated (n = 568) hypertensive patients (386 men, 414 women, mean age 52.7 +/- 11.8 years) referred for the first time to our out-patient clinic were included in the study. In order to search for target organ damage, they were submitted to the following procedures: 1) amydriatic retinography, 2) 24-hour urine collection for microalbuminuria, 3) echocardiography, and 4) carotid ultrasonography. Retinal changes were evaluated according to the Keith, Wagener and Barker (KWB) classification by two physicians, who had no knowledge of the patients' characteristics. Microalbuminuria was defined as a urinary albumin excretion > 30 and < 300 mg/24 hours, LVH as a left ventricular mass index > or = 134 g/m2 in men and > or = 110 g/m2 in women; finally carotid plaque was defined as a focal thickening > 1.3 mm.
Results: Hypertensive retinopathy was the most frequent (KWB grade I 46%, II 32%, III-IV < 2%) marker of target organ damage, followed by carotid plaques (43%), LVH (22 %, eccentric LVH was the prevalent type and was 1.8 times as frequent as the concentric one) and microalbuminuria (14%).
Conclusions: At variance with the markers of cardiac, macrovascular and renal damage, an extremely high prevalence of retinal abnormalities (narrowings and initial arterio-venous crossings) were found in our population. If, as suggested by the WHO/ISH guidelines, these retinal abnormalities were considered as a reliable marker of target organ damage, then almost all patients would be affected by hypertensive vascular disease. Based on this evidence it is suggested that retinal abnormalities included in funduscopic grades I and II of the KWB classification should not be considered among the criteria for the quantitative detection of target organ damage.