Impact of type 1 diabetes and its duration on wall-to-lumen ratio and blood flow in retinal arterioles.

BACKGROUND: Subclinical damage to both the small and large vessels may contribute to the development and progression of cardiovascular disease. Scanning laser Doppler flowmetry (SLDF), an established method used to measure retinal microcirculation, has been successfully applied in hypertensive and post-stroke patients. METHODS: Retinal microcirculation was assessed in 158 patients with type 1 diabetes and 38 age-matched healthy controls. The diabetics were divided into 3 groups: group A with diabetes duration <12 months, group B with diabetes with 1-10 years, and group C >10 years of diabetes. Retinal capillary structure and perfusion were evaluated using a Heidelberg retina flowmeter and automatically analyzed with full-field perfusion imaging. RESULTS: Age and BMI were comparable in all the diabetic patients and the controls (mean age 24.8 ± 4.7 years, mean BMI 22.9 ± 4.1). In the univariate analyses, RCF (retinal capillary flow) was significantly higher in group A (297 ± 121 arbitrary units [AU]) vs group B (236 ± 52 AU; p = 0.007) and group C (236 ± 70 AU; p = 0.008) and comparable to that of the controls (p = 0.46). Additionally, the WLR (Wall-to-Lumen Ratio) was highest in group C compared to the other diabetic subgroups and controls (p = 0.001). Multivariate regression analyses including age, BMI, sex, HbA1c, smoking, systolic blood pressure, and diabetes duration as covariates, showed, that only diabetes duration was significantly associated with WLR variations, whereas HbA1c was significantly linked to retinal capillary flow levels. CONCLUSIONS: New-onset diabetes is associated with an increase in RCF, which then gradually decreased with the duration of the disease. Structural changes of the retinal arterioles estimated via WLR are evident later in the course of diabetes, especially when the disease duration exceeded 10 years.

Aortic stiffness is not only associated with structural but also functional parameters of retinal microcirculation.

OBJECTIVE: The aim of the study was to test the hypothesis that alterations in large arteries are associated with microvascular remodelling and decreased retinal capillary blood flow. METHODS: The study group comprised of 88 patients with essential hypertension and 32 healthy controls. Retinal microcirculation was evaluated by scanning laser Doppler flowmetry. Macrovascular changes were assessed on the basis of arterial stiffness measurement (carotid-femoral pulse wave velocity), its hemodynamic consequences (central pulse pressure, augmentation pressure, augmentation index) and intima media thickness of common carotid artery. RESULTS: Pulse wave velocity was inversely correlated to mean retinal capillary blood flow in hypertensive patients (R = -0.32, p < 0.01). This relationship remained significant in multivariate regression analysis after adjustment for age, sex, central systolic blood pressure (BP) and body mass index (ß = -31.27, p < 0.001). Lumen diameter (LD) of retinal arterioles was significantly smaller in hypertensive then normotensive subjects (79.4 vs. 83.8, p = 0.03). Central and brachial systolic, diastolic and mean BPs were significantly correlated with LD and outer diameter of retinal arterioles. The relationship between LD and central BPs remained significant in multivariate analysis (ß = -0.15, p = 0.03 for cSBP; ß = -0.22, p = 0.04 for cDBP; ß = -0.21, p = 0.03 for cMBP). Moreover, in a subgroup with cardiac damage central and brachial pulse pressure were positively associated with retinal wall thickness, wall cross sectional area, and wall to lumen ratio. CONCLUSION: In conclusion, the study provides a strong evidence that microcirculation is coupled with macrocirculation not only in terms of structural but also functional parameters.

Lumen narrowing and increased wall to lumen ratio of retinal microcirculation are valuable biomarkers of hypertension-mediated cardiac damage.

Purpose: In the course of hypertension, left ventricular hypertrophy and diastolic dysfunction develop very often and may progress toward heart failure. The aim of the study was to analyze the relationship between abnormalities of retinal microcirculation and cardiac damage defined as left ventricular hypertrophy and/or diastolic dysfunction.Materials and methods: The study comprised 88 patients with essential hypertension. The group was divided into two subgroups: hypertensives without cardiac damage (n = 55) and with cardiac damage (n = 33). Control group comprised 32 normotensive subjects. Scanning laser Doppler flowmetry was used to evaluate retinal microcirculation. Echocardiography was used to assess cardiac damage.Results: Lumen diameter of retinal arterioles was significantly smaller in patients with cardiac damage vs. controls (77 vs. 84 µm, p = 0.02). Additionally, there was an evident trend with respect to lumen diameter (LD) across all three studied subgroups; i.e.: the smallest dimeters were present in cardiac damage patients, moderate size in hypertensives' without cardiac damage, and the largest diameters in healthy controls (pfor trend < 0.01). Lumen diameter was inversely correlated with cardiac intraventricular septum diameter (R = -0.25, p = 0.02), left ventricular mass (R = -0.24, p = 0.02), and left atrial volume (R = -0.22, p = 0.04). Wall to lumen ratio was associated with intraventricular septum diameter (R = 0.21, p = 0.044) and left atrial volume (R = 0.21, p = 0.045). In multivariable regression analysis, lumen diameter was independently associated with intraventricular septum diameter (ß = -0.05, p = 0.03), left ventricular mass (ß = -1.15, p = 0.04), and left atrial volume (ß = -0.42, p = 0.047); wall to lumen ratio was independently associated with intraventricular septum diameter (ß = 3.67, p = 0.02) and left atrial volume (ß = 30.0, p = 0.04).Conclusions: In conclusion, retinal arterioles lumen diameter and wall to lumen ratio were independent biomarkers of cardiac damage. Retinal examination performed by means of scanning laser Doppler flowmetry might be a valuable tool to improve cardiovascular risk stratification of hypertensive patients.

Non-invasive hemodynamic monitoring as a guide to drug treatment of uncontrolled hypertensive patients: effects on home blood pressure in the BEAUTY study.

BACKGROUND: In the BEAUTY study we investigated whether utilizing non-invasive monitoring of hemodynamic parameters combined with a drug selection algorithm (integrated hemodynamic management-IHM) compared to conventional drug selection may improve home BP in patients with uncontrolled hypertension. METHODS: Uncontrolled (office systolic blood pressure (SBP) > 140 mmHg and ambulatory daytime SBP >135 mmHg while taking ≥2 antihypertensive drugs) essential hypertensive patients were referred to 5 European Hypertension Excellence Centers and, if eligible, were randomized into IHM-guided vs conventional treatment adjustment. Home blood pressure (BP) was taken with 2 repeated readings at 1-2 min intervals in the morning and in the evening (before drug intake and eating) during the week preceding the visit at the outpatient clinic after 5 min rest using a validated semi-automatic oscillometric arm cuff device and with a correct cuff bladder placement. Home blood pressure was measured in a sub-group of patients (n = 84) not significantly different from the other patients. RESULTS: Home SBP changed from 152.1+/-15.8 and 149.8+/-11.8 mmHg to 131.0 +/-11.1 and 139.6+/-12.8 mmHg in IHM group (n = 46) and Control group (n = 38), respectively, showing significantly greater reduction in IHM than in Control group (d= -10.9 mmHg, 95% CI -17.77, -4.02), p = 0.002. The reduction remained significant after multiple adjustments, particularly for baseline home SBP, recruiting center, age, sex and BMI (SBPIHM-Control= -9,63 mmHg, 95% CI -14.28, -5.11) mmHg, p < 0.0001). CONCLUSION: Drug selection algorithm based on non-invasive hemodynamic monitoring induced larger reduction in home BP compared to conventional drug selection in uncontrolled hypertensive patients referred to European Hypertension Excellence Centers. Although the main BEAUTY study was negative, these home BP measurements taken by patients themselves may suggest that the integrated hemodynamic monitoring is useful in patients with uncontrolled hypertension. This finding might depend on specific features of home BP measurements which could make it recommended BP measurement method for drug trials.

The accuracy of SpaceLabs 90207 in blood pressure monitoring in patients with atrial fibrillation.

PURPOSE: Irregular heart rhythm in the course of atrial fibrillation (AFib) results in lower blood pressure (BP) measurements reproducibility which is further limited by various BP-monitors used. Therefore the aim of our study was to estimate accuracy of oscillometric BP measurement (SpaceLabs 90207) with reference to mercury manometer-based readings. MATERIAL AND METHODS: Study was performed in 47 hemodynamically stable patients aged 63 ± 12 yo with paroxysmal or persistent AFib, at baseline. Patients were reassessed within one week after effective cardioversion (SR; n = 29). BP was measured using Y-tube connection allowing for simultaneous measurements on the same arm with SpaceLabs 90207 and referral method. Mean values were tested with paired t-tests. Additionally, concordance correlation coefficient (ρc) and Bland-Altman plots were assessed. Results were confronted with AAMI, and ESH-IP criteria. RESULTS: Both during arrhythmia and sinus rhythm diastolic BP differed significantly (Δ = 4.6 ± 6.0 mm Hg, p < .001 and 2.1 ± 4.0 mm Hg, p < .001; for AFib, and SR, respectively), which was not the case for systolic BP. The ρc during arrhythmia equaled 0.89, and 0.75 for systolic and diastolic BP, respectively, which further improved while SR (0.96 and 0.89, respectively). Results confronted against AAMI and ESH-IP showed that all criteria were met except for one (60% vs. required 65% of paired differences of less than 5 mm Hg) during AFib. CONCLUSIONS: The direct comparisons of BP readings allowed to conclude that diastolic blood pressure tended to be slightly overestimated when assessed with SpaceLabs 90207 in patients with both, AFib and SR, which was not a case for systolic BP. When the results were confronted with available validation protocols requirements, all referral criteria were met except for one. Taken together, our results suggest acceptable BP readings dispersion of SpaceLabs 90207 in BP monitoring of patients with both AFib and SR.

A randomized and controlled study of noninvasive hemodynamic monitoring as a guide to drug treatment of uncontrolled hypertensive patients.

BACKGROUND: In the BEtter control of BP in hypertensive pAtients monitored Using the HOTMAN sYstem study, we investigated whether utilizing noninvasive monitoring of hemodynamic parameters combined with a drug selection algorithm (integrated hemodynamic management - IHM) compared with conventional drug selection may improve uncontrolled hypertension in European Hypertension Excellence centers. METHOD: Uncontrolled (office SBP >140 mmHg and ambulatory daytime SBP >135 mmHg while taking ≥2 antihypertensive drugs) essential hypertensive patients were referred to five European Hypertension Excellence centers and, if eligible, were randomized to IHM-guided (n = 83) vs. conventional (control, n = 84) treatment adjustment in an investigator-initiated multicenter prospective randomized parallel groups controlled study. RESULTS: The average number of antihypertensive drugs increased from 3.1 to 4.1 in both groups and differed only in a rise of the use of diuretics in the IHM groups (from 13 to 31%). Daytime SBP, defined as the primary endpoint, decreased markedly and to the same extent from baseline to 6 months in IHM (-15.8 ±â€Š14.8 mmHg) and control (-15.4 ±â€Š14.5 mmHg) groups (P = 0.87), with a similar behavior of office SBP (no between group differences, P = 0.18). Average number of adverse events was significantly lower in IHM than in controls (P = 0.008) but of the more general type and not necessarily related to drug treatment. CONCLUSION: Thus, noninvasive hemodynamic monitoring associated with a drug selection algorithm induced similar reductions in ambulatory daytime and office SBP compared with conventional drug selection in uncontrolled hypertensive patients referred to European Hypertension Excellence centers.Clinical Trial Registration - URL: http://www.clinicaltrials.gov. Unique identifier: NCT01482364.