Improving cardiovascular risk stratification: the case for redefining microalbuminuria.

Large epidemiological studies have pointed out that regardless of the degree of hypertension, the cost-effectiveness of antihypertensive treatment increases in parallel with the global burden of risk. Therefore, there has been growing interest in developing sensitive and easy-to-perform ways to accurately and inexpensively identify patients at high cardiovascular risk. Numerous studies over the past years have provided evidence that microalbuminuria is a concomitant of extrarenal signs of hypertensive organ damage, as well as a strong, independent predictor of cardiovascular and cerebrovascular events. Recent clinical data indicate that the risk of cardiovascular morbidity and mortality is linearly related to the degree of urinary albumin excretion, with no identifiable threshold or plateau. Furthermore, it has been demonstrated that a reduction in albuminuria under antihypertensive treatment is paralleled by changes in cardiovascular risk. Therefore, the routine search for microalbuminuria could lead to a significant improvement in the evaluation and treatment of patients with primary hypertension.

Microalbuminuria and cardiovascular risk assessment in primary hypertension: should threshold levels be revised?

BACKGROUND: Urinary albumin excretion and left ventricular mass are related to each other and to the risk of cardiovascular events in patients with primary hypertension. We aimed to identify a lower threshold for albuminuria that might improve detection of patients with left ventricular hypertrophy (LVH) and cost-effectiveness in cardiovascular risk assessment. METHODS: Albuminuria and left ventricular mass index were assessed in 448 untreated, nondiabetic patients with primary hypertension. The impact that lower albuminuria cut-off levels might have on detecting LVH was evaluated with regard to test cost and sensitivity. This was done by a diagnostic algorithm consisting of albuminuria evaluation followed by echocardiography in the presence of normoalbuminuria. RESULTS: The area under the ROC curve of albuminuria in predicting LVH was 0.73. Using a lower albumin to creatinine ratio threshold than what is recommended by the guidelines (ie, 11.5 mg/g), the sensitivity and specificity of albuminuria in identifying patients with LVH was 39% and 92%, respectively, which translated to positive and negative predictive values of 76% and 69%, respectively. When considering only patients without electrocardiographically detected LVH, routine screening for albuminuria, followed by echocardiography in the presence of albuminuria

Evaluation of subclinical organ damage for risk assessment and treatment in the hypertensive patient: role of microalbuminuria.

Microalbuminuria, i.e., abnormal urinary excretion of albumin, which is detectable by low cost and widely available tests, is a first-line tool for identifying hypertensive patients who are at higher cardiovascular (CV) risk. Numerous studies have provided evidence that microalbuminuria is a concomitant of cardiac and vascular damage as well as a strong, independent predictor of CV events. An important, emerging issue is that the risk for CV morbidity and mortality is linearly related to urinary albumin excretion and persists well below the currently used cutoff for defining microalbuminuria. Furthermore, late-breaking evidence suggests that a reduction of albuminuria under antihypertensive treatment is paralleled by changes in CV risk. The routine search for target organ damage by means of microalbuminuria could lead to a significant improvement in the evaluation and treatment of patients with primary hypertension.

Role of microalbuminuria in the assessment of cardiovascular risk in essential hypertension.

Accurate cardiovascular risk evaluation is a prerequisite for devising cost-effective therapeutic strategies in patients with essential hypertension. In fact, the knowledge of concomitant risk factors, diabetes, target organ damage, or associated clinical conditions may be useful when deciding both treatment and BP goals. Thorough evaluation of target organ damage is the key to sensitive assessment of global risk, but cost-effective allocation of economic resources should also be taken into consideration. Thanks to its low cost and widespread availability, the search for microalbuminuria is a first-line tool for identifying hypertensive patients who are at higher cardiovascular risk.

Impact of target organ damage assessment in the evaluation of global risk in patients with essential hypertension.

Accurate assessment of cardiovascular risk is a key step toward optimizing the treatment of hypertensive patients. We analyzed the impact and cost-effectiveness of routine, thorough assessment of target organ damage (TOD) in evaluating risk profile in hypertension. A total of 380 never-treated patients with essential hypertension underwent routine work-up plus evaluation of albuminuria and ultrasonography of cardiac and vascular structures. The impact of these tests on risk stratification, as indicated by European Society of Hypertension-European Society of Cardiology guidelines, was assessed in light of their cost and sensitivity. The combined use of all of these tests greatly improved the detection of TOD, therefore leading to the identification of a higher percentage of patients who were at high/very high risk, as compared with those who were detected by routine clinical work-up (73% instead of 42%; P < 0.0001). Different signs of TOD only partly cluster within the same subgroup of patients; thus, all three tests should be performed to maximize the sensitivity of the evaluation process. The diagnostic algorithm yielding the lowest cost per detected case of TOD is the search for microalbuminuria, followed by echocardiography and then carotid ultrasonography. Adopting lower cut-off values to define microalbuminuria allows us to optimize further the cost-effectiveness of diagnostic algorithms. In conclusion, because of its low cost and widespread availability, measuring albuminuria is an attractive and cost-effective screening test that is especially suitable as the first step in the large-scale diagnostic work-up of hypertensive patients.

Optimizing global risk evaluation in primary hypertension: the role of microalbuminuria and cardiovascular ultrasonography.

OBJECTIVE: To assess the impact and cost-effectiveness of microalbuminuria and cardiovascular ultrasonography in evaluating the risk profile in primary hypertension. METHODS: Four hundred and five untreated patients with primary hypertension underwent a routine, traditional work-up plus evaluation of albuminuria and ultrasound (US) assessment of cardiac and vascular structures. Albuminuria was measured as the albumin to creatinine ratio in three non-consecutive first-morning urine samples. Left ventricular mass index was assessed by MB-mode echocardiography and carotid intima-media thickness by high-resolution US scan. The impact of these tests on patient risk classes, as indicated by European Society of Hypertension-European Society of Cardiology (ESH-ESC) guidelines, was assessed with respect to their cost and sensitivity. RESULTS: The prevalence of microalbuminuria, left ventricular hypertrophy and carotid intima-media thickening or carotid plaque was 13, 49 and 32%, respectively. The combined use of albuminuria, cardiac and vascular ultrasonography led to the detection of a significantly higher percentage of patients at high/very high risk. The three tests differ in sensitivity (albuminuria, 20%; echocardiography, 65%; and carotid ultrasound, 41%). The signs of target organ damage (TOD) only partly cluster within the same subgroup of patients and, thus, all three tests should be performed in order to maximize the sensitivity of the evaluation process. The diagnostic algorithm yielding the lowest cost per detected case of TOD is the search for microalbuminuria followed by cardiac and carotid ultrasound assessment. CONCLUSIONS: Ultrasonographic detection of TOD is a sensitive tool in the identification of high-risk patients, but should be preceded by a routine search for microalbuminuria in order to optimize the cost-effectiveness of the diagnostic work-up.

Cardiovascular and renal risk assessment as a guide for treatment in primary hypertension.

BP levels per se may be an unreliable indicator of risk in the individual patient. In fact, the global cardiovascular profile, including the presence and degree of target organ damage, is a better predictor of future events and, therefore, should be used to choose both treatment and BP goals. However, the prevalence of target organ damage and therefore the percentage of patients who are at risk very much depends on the diagnostic techniques used. However, as a result of the high prevalence of hypertension and its financial impact on public health systems, limiting unnecessary and extensive diagnostic tests also should be a priority. The routine search for microalbuminuria may lead to the detection of a significantly greater percentage of patients who are at high risk while contributing the optimization of the cost-effectiveness of diagnostic workup in hypertensive patients.