Importance of the Electrocardiographic Strain Pattern in Patients With Resistant Hypertension

Electrocardiographic differences in patients with true and pseudo-resistant hypertension

Cardiovascular disease is the leading cause of mortality in hypertensives, and patients with true resistant hypertension have an increased risk for premature cardiovascular events. Electrocardiography (ECG) has an essential role in the monitoring of hypertensive heart disease; however, little is known about the importance of ECG parameters in patients with resistant hypertension. We aimed to investigate whether fragmented QRS (fQRS) and frontal plane QRS-T angle, which are novel ECG parameters indicating myocardial damage, predict true resistant hypertension in patients with uncontrolled blood pressure. Four hundred six hypertensive patients with resistant hypertension were prospectively enrolled for the study. Patients were divided into two groups as 'true resistant' or 'pseudo-resistant' hypertensives and compared regarding the ECG parameters. While 73 (18%) patients had true resistant hypertension, 333 (82%) patients had pseudo-resistant hypertension. The frequency of fQRS (47.9% vs. 20.1%, p < 0.001) and average frontal plane QRS-T angle (93.0° ± 19.7° vs. 53.8° ± 10.2°, p < 0.001) were significantly higher in patients with true resistant hypertension compared to those with pseudo-resistant hypertension. Also, fQRS in anterior leads was significantly more frequent in patients with true resistant hypertension (57.1% vs. 23.8%, p < 0.001). Moreover, ROC curve analysis demonstrated that an increased frontal plane QRS-T angle > 90.75° predicted true resistant hypertension with a sensitivity 96% and specificity 61% (AUC:0.874, p < 0.001). Furthermore, multivariate analysis demonstrated that fQRS in anterior leads (OR: 1.251, 95% CI: 1.174-1.778, p = 0.002) and frontal plane QRS-T angle (OR: 1.388, 95% CI: 1.073-1.912, p < 0.001) were independent predictors of true resistant hypertension. In conclusion, fQRS and frontal plane QRS-T angle may be useful to predict true resistant hypertension in patients with uncontrolled blood pressure.

The association of severity of retinal vascular changes and cardiac remodelling in systemic hypertension

OBJECTIVES

The aim of the study was to explore the association between hypertensive retinopathy, grades of retinopathy and cardiac remodelling.

METHODS

This was a cross-sectional observational study. A total of 500 consecutive hypertensive adults from the in-patient population were studied for the presence of hypertensive retinopathy by dilated fundoscopy. The presence of cardiac remodelling due to hypertension was studied both by electrocardiography (ECG) and echocardiography. Hypertensive target organ damage in other organs was also screened. In addition, the association of grades of hypertensive retinopathy with target organ damage was also analyzed.

RESULTS

Systolic blood pressure (BP) at presentation and duration of hypertension showed no relationship with markers of hypertensive heart disease. However, diastolic BP was significantly higher in patients with retinopathy. Hypertensive retinopathy was diagnosed in 324 subjects of whom 90 had grades 3 and 4 retinopathy. Patients with grades 3 and 4 retinopathy had significant associations with ECG evidence of left ventricular (LV) strain pattern and left atrial enlargement, and a weaker association with left ventricular hypertrophy (LVH) using QRS voltage criteria (Sokolov-Lyon). On echocardiography, grades 3 and 4 retinopathy were significantly associated with LVH, left atrial enlargement and reduced left ventricular ejection fraction (LVEF), as well as with higher creatinine values. A large number of these patients presented with heart failure. Cardiac remodelling was not seen in patients without retinopathy and was uncommon in patients with grades 1 and 2 retinopathy.

CONCLUSION

Grades 3 and 4 retinopathy demonstrated a significant association with LV strain pattern and left atrial enlargement on ECG, LVH and reduced LVEF on echocardiography as well as with heart failure. There was no relationship with systolic BP and duration of hypertension, while diastolic BP showed a significant positive correlation. Signs of hypertensive heart disease were practically absent in patients without hypertensive retinopathy and uncommon in those with grade 1-2 alterations.

Cardiovascular and renal complications in patients with resistant hypertension

With an increased prevalence, resistant hypertension is recognized as an entity with a high cardiovascular morbidity and mortality. In a large cohort of patients with resistant hypertension, the crude incidence rate of total cardiovascular events reached 4.32 per 100 patient-years of follow-up (19.6 %), with a cardiovascular mortality of 8.3 % (incidence rate of 1.72 per 100 patient-years). Cardiovascular event rates are significantly higher in resistant hypertensives compared with non-resistant (18.0 % versus 13.5 %). In the same way, the prevalence of established cardiovascular and renal disease, as the asymptomatic organ damage (represented by left ventricular hypertrophy, carotid wall thickening, arterial stiffness, and microalbuminuria) is higher in these patients. Many studies have demonstrated a strong association between damage to these organs with higher blood pressure levels, the diagnosis of true resistant hypertension, and refractory hypertension. All efforts should be employed in order to control blood pressure and also to regress and/or prevent subclinical cardiovascular and renal damage. The focus should be on prevention of cardiovascular and renal complications, improving the prognosis of resistant hypertension.

Influence of the left ventricular types on QT intervals in hypertensive patients

Objective:

To investigate the possible electrophysiological background of the greater excitability of concentric and eccentric left ventricular hypertrophy types in relation to the asymmetric type.

Methods:

187 patients with essential hypertension, without ishaemic heart disease were divided into three groups with regard to left ventricule type: concentric (relative wall thickness >0.42, interventricular septum/left ventricular posterior wall ≤1.3), eccentric (left ventricular diameter in systoles >32, relative wall thickness <0.42), asymmetric left ventricular hypertrophy (interventricular septum/left ventricular posterior wall >1.3), and three subgroups: mild (interventricular septum or left ventricular posterior wall 11-12 mm), moderate (interventricular septum or left ventricular posterior wall 13-14 mm) and severe left ventricular hypertrophy (interventricular septum or left ventricular posterior wall ≥15 mm). In all patients QT intervals, QT dispersion, left ventricular mass index and ventricular arrhythmias were measured. An upper normal limit for QT corrected interval: 450/460 ms for men/women; for QT dispersion: 70 ms.

Results:

The QT corrected interval and QT dispersion were increased in severe concentric and eccentric left ventricular hypertrophy (443 and 480 ms for QT corrected; 53 and 45 ms for QT dispersion, respectively), not significantly. QT dispersion in men with severe left ventricular hypertrophy was significantly enlarged (67.5 vs. 30 ms, p=0.047). QT interval was significantly longer in patients with complex ventricular arrhythmias (p=0.037).

Conclusion:

No significant association of QT intervals or QT dispersion with the degree/type of left ventricular hypertrophy was found. QT corrected interval and QT dispersion tend to increase proportionally to the left ventricular mass only in the concentric and eccentric type.

Resistant hypertension and target organ damage

Cardiovascular (CV) complications such as myocardial infarction, heart failure, stroke and renal failure are related to both the degree and the duration of blood pressure (BP) increase. Resistant hypertension (RH) is associated with a higher risk of CV complications and a higher prevalence of target organ damage (TOD). The relationship between CV disease and TOD can be bidirectional. Elevated BP in RH may cause CV structural and functional alterations, and the development or persistence of left ventricular hypertrophy, aortic stiffness, atherosclerotic plaques, microvascular disease and renal dysfunction, may render hypertension more difficult to control. Specifically, RH is related to several conditions, including obesity, sleep apnea, diabetes, metabolic syndrome and hyperaldosteronism, characterized by an overexpression of humoral and hormonal factors that are involved in the development and maintenance of TOD. Optimal therapeutic strategies, including pharmacological treatment and innovative invasive methodologies, have been shown to achieve adequate BP control and induce the regression of TOD, thereby potentially improving patient prognosis.

Prognostic factors in resistant hypertension: implications for cardiovascular risk stratification and therapeutic management

Resistant hypertension (RH) is defined as uncontrolled office blood pressure (BP) in spite of the use of at least three antihypertensive medications. Although its condition has a high prevalence, it is still understudied, and its prognosis is not well established. Some prospective studies evaluated the prognostic value of ambulatory BP monitoring, ECG and renal parameters. They pointed out that ambulatory BPs are important predictors of cardiovascular morbidity and mortality, whereas office BP has no prognostic value. The diagnosis of true RH and the nondipping pattern are also valuable predictors of cardiovascular outcomes. Moreover, several ECG (prolonged ventricular repolarization, serial changes in the strain pattern and left ventricular hypertrophy) and renal parameters (albuminuria and reduced glomerular filtration rate) are also powerful cardiovascular risk markers in RH. These markers and others yet unexplored, such as arterial stiffness and serum biomarkers, may improve cardiovascular risk stratification in these very high-risk patients.

Prevalence and associated factors of subclinical hypercortisolism in patients with resistant hypertension

BACKGROUND

Subclinical hypercortisolism is a secondary cause of hypertension that had never been evaluated in resistant hypertensive patients, a subgroup of general hypertensive individuals with an expected high prevalence of secondary hypertension.

METHODS

Four hundred and twenty-three patients with resistant hypertension and ages up to 80 years were screened for the presence of subclinical hypercortisolism by morning serum cortisol after a midnight 1 mg dexamethasone suppression test (DST). Those with morning cortisol of at least 50  nmol/l had hypercortisolism confirmed by two salivary cortisol of at least 3.6  nmol/l collected at 2300  h. Statistical analysis included bivariate tests between those with positive and negative screening test and with and without confirmed hypercortisolism, and logistic regressions to assess their independent correlates.

RESULTS

One hundred and twelve patients (prevalence 26.5%, 95% confidence interval 22.0-31.9%) had the screening test positive for suspected hypercortisolism. None had overt Cushing syndrome. Patients with positive screening were older, more frequently males, had higher prevalences of diabetes and target-organ damage and higher nighttime SBPs than patients with normal screening test results. Thirty-four patients (total prevalence 8.0%, 95% confidence interval: 5.7-11.2%) had confirmed hypercortisolism. Independent correlates of a positive DST were older age (P = 0.007), male sex (P = 0.012) and presence of cardiovascular diseases (P = 0.002) and chronic kidney disease (P = 0.016). Correlates of confirmed subclinical hypercortisolism were older age (P = 0.020), diabetes (P = 0.06) and a nondipping pattern on ambulatory blood pressure monitoring (P = 0.04).

CONCLUSION

Patients with resistant hypertension had a relatively high prevalence of subclinical hypercortisolism, and its presence is associated with several markers of worse cardiovascular prognosis.

[Prevalence of target organ damage and metabolic abnormalities in resistant hypertension]

BACKGROUND AND OBJECTIVE

Patients with resistant hypertension (RH) are relatively frequently visited in specialized units of hypertension. The aim of this study was to assess the prevalence of target organ damage, central obesity and metabolic syndrome in a cohort of patients with RH consecutively included in the Register of Resistant Hypertension of the Spanish Society of Hypertension (SHE-LELHA).

PATIENTS AND METHODS

Cross-sectional, multicenter epidemiologic study in usual clinical practice conditions. Patients with clinical diagnosis of resistant hypertension, that is, office systolic and diastolic blood pressure ≥ 140 mm Hg and/or ≥ 90 mm Hg, respectively, despite a prescribed therapeutic schedule with an appropriate combination of three or more full-dose antihypertensive drugs, including a diuretic, were consecutively recruited from specialized hypertension units spread through Spain. Demographic and anthropometric characteristics as well as cardiovascular risk factors and associated conditions were recorded, and all the subjects underwent 24-h ambulatory blood pressure monitoring. Left ventricular hypertrophy was considered as a left ventricular mass index ≥ 125 g/m(2) in males and ≥ 110 g/m(2) in females. Left atrial enlargement was defined as an indexed left atrium diameter ≥ 26 mm/m(2). Microalbuminuria was defined as a urinary albumin/creatinine ratio ≥ 22 mg/g in males and ≥ 31 mg/g in females.

RESULTS

513 patients were included, aged 64±11 years old, 47% women. Central obesity was present in 65.7% (CI 95% 61.6-69.9), 38.6% (CI 95% 34.4-42.8) had diabetes and 63.7% (CI 95% 59.4-67.9) had metabolic syndrome. The prevalence of left ventricular hypertrophy and left atrial enlargement, determined by echocardiography was 57.1% (CI 95% 50.8-63.5) and 10.0% (CI 95% 6.3-13.7) respectively. Microalbuminuria was found in 46.6% (CI 95% 41.4-51.8) of the subjects. Patients with metabolic syndrome were significantly older (65.4±11 and 62.5±12 years; P=.0052), presented a higher prevalence of diabetes (52.0% vs. 16.6; P<.0001) and were treated more frequently with ≥ 4 antihypertensive drugs (65.1 vs. 50.0%, P=.011).

CONCLUSION

The prevalence of central obesity, metabolic syndrome and target organ damage is very high in resistant hypertensive subjects.

Resistant hypertension and left ventricular hypertrophy: an overview

Available data on subclinical cardiac damage in resistant hypertension (RH) are rather scanty. Thus, we sought to review the literature focusing on the association between RH and left ventricular hypertrophy (LVH). A MEDLINE search was performed to identify relevant articles using the key words "resistant hypertension, " "refractory hypertension," "left ventricular hypertrophy," "cardiac damage," and "left ventricular dysfunction." Full articles published in the English language in the last two decades (December 1, 1989, to July 31, 2010) reporting studies in adult or elderly individuals, were considered. Checks of the reference lists of selected articles complemented the electronic search. A total of 11 cross-sectional and longitudinal studies, including 3325 patients attending outpatient hypertension clinics, were considered. Prevalence rates of echocardiographic LVH, as assessed by updated criteria, ranged from 55% to 75% of patients with RH, peaking to 91% in the subgroup with concomitant electrocardiographic (ECG) LV strain. Reduction in ECG-LVH induced by treatment showed a relevant beneficial impact on cardiovascular prognosis. These data support the view that initial and on-treatment assessment of LVH in patients with RH is important for cardiovascular risk monitoring and therapeutic strategies decision-making.

Prognostic significance of baseline and serial changes in electrocardiographic strain pattern in resistant hypertension

OBJECTIVES

The prognostic importance of serial changes in electrocardiographic strain pattern of lateral ST-depression and T-wave inversion is unclear. The objective was to evaluate the significance of baseline and serial changes in strain pattern as predictors of cardiovascular morbidity and mortality in patients with resistant hypertension.

METHODS

At baseline and during follow-up, 532 resistant hypertensive patients had the presence of strain pattern examined on 12-lead ECGs. Other clinical laboratory, echocardiographic and ambulatory blood pressure data were obtained. Primary endpoints were a composite of total cardiovascular events and mortality. Strokes and coronary heart disease events were secondary endpoints. Multiple Cox regression assessed the associations between strain pattern and subsequent endpoints.

RESULTS

At baseline, 115 patients (21.6%) presented the strain pattern and during follow-up, 17 patients regressed and 22 developed new strain pattern. After a median follow-up of 4.8 years, 69 patients died, 46 from cardiovascular causes; and 107 cardiovascular events occurred, 44 strokes and 42 coronary heart disease events. After adjustment for several cardiovascular risk factors, including time-varying ambulatory blood pressures and electrocardiographic voltage criteria of left ventricular hypertrophy, the persistence or development of strain during follow-up was a predictor of the composite endpoint (hazard ratio 1.97, 95% confidence interval 1.19-3.25), all-cause mortality (hazard ratio 1.99, 95% confidence interval 1.10-3.61) and of stroke (hazard ratio 3.09, 95% confidence interval 1.40-6.81). The combination of strain pattern and left ventricular hypertrophy voltage criteria improved stratification of cardiovascular risk.

CONCLUSION

Serial changes in electrocardiographic strain pattern during follow-up predict cardiovascular morbidity and mortality in resistant hypertensive patients. Regression or prevention of the strain pattern during antihypertensive treatment may be a therapeutic goal to improve prognosis.

Electrocardiographic strain pattern in children with left ventricular hypertrophy: a marker of ventricular dysfunction

The objective of this study was to assess the relation between strain pattern on electrocardiogram (ECG-strain) and echocardiographic indices of left ventricular (LV) structure and function in children with LV hypertrophy (LVH). ECG-strain is a marker of LVH and is associated with adverse cardiovascular prognosis in adults. The significance of ECG-strain and its relation to LV structure and function has not been studied in children. We retrospectively analyzed electrocardiograms (ECGs) and echocardiograms of 101 children enrolled in this study. Subjects were divided into three groups: group I (n = 21) comprised children with LVH confirmed by echocardiography (LVH(echo)) with ECG-strain pattern; group II (n = 54) comprised children with LVH(echo) without ECG-strain pattern; and group III (n = 26) comprised children without LVH (control group). ECG-strain was defined as a down-sloping convex ST-segment depression (> or = 0.1 mV) with an inverted asymmetrical T-wave opposite to the QRS axis in leads V5 and/or V6. LV structure and function was measured using conventional and tissue Doppler echocardiography. ECG-strain was associated with greater interventricular septal thickness, posterior wall thickness, and LV mass index (LVMI) compared with those without ECG-strain (P < 0.0001 for each variable). Concentric LVH was more common in those with ECG-strain (16 of 21 vs. 9 of 54 patients; P = < 0.0001). ECG-strain was associated with systolic, diastolic, and combined systolic-diastolic dysfunction in children with LVH(echo). Among children with LVH, ECG-strain is associated with higher LVMI, concentric pattern of LVH, and LV systolic and diastolic dysfunction. Whether this has similar adverse prognostic implications as it does in adults remains to be determined.

Prognostic value of ventricular repolarization prolongation in resistant hypertension: a prospective cohort study

OBJECTIVE

The prognostic value of prolonged ventricular repolarization in patients with resistant hypertension is unknown. The aim of this prospective study was to investigate the usefulness of electrocardiographic QT-interval parameters as predictors of cardiovascular morbidity and mortality.

METHODS

At baseline, 538 resistant hypertensive patients had five QT-interval components measured in standard 12-lead ECGs: maximum QRS, QTpeak, QTend, JT and Tpeak-to-end-interval durations. Primary endpoints were a composite of fatal and nonfatal cardiovascular events, all-cause and cardiovascular mortalities. Multiple Cox regression assessed the associations between QT-interval parameters and subsequent endpoints.

RESULTS

After a median follow-up of 4.8 years, 69 (12.8%) patients died, 46 from cardiovascular causes, and 107 (19.9%) fatal or nonfatal cardiovascular events occurred. After adjustment for several traditional risk factors, including 24-h ambulatory systolic blood pressure, an increment of 1 SD (35 ms) in QTcend-interval was associated with hazard ratios of 1.38 (1.15-1.67), 1.51 (1.16-1.98) and 1.30 (1.03-1.64), respectively, for the composite endpoint, cardiovascular mortality and all-cause mortality. Further adjustment for left ventricular hypertrophy attenuated the relative risks, but they remained significant for cardiovascular mortality (1.45, 1.07-1.97) and for the composite endpoint (1.35, 1.11-1.66). After full adjustment, a prolonged QTcend-interval (> or =460 ms) conferred a 1.7-fold (1.1-2.6) higher risk of having a future fatal or nonfatal cardiovascular event. No other QT-interval component added further prognostic information to QTcend-interval duration.

CONCLUSIONS

Prolonged ventricular repolarization is a risk marker for cardiovascular morbidity and mortality in patients with resistant hypertension, over and beyond traditional cardiovascular risk factors, including ambulatory blood pressure and left ventricular hypertrophy.

Ambulatory arterial stiffness index or pulse pressure: which correlates better with arterial stiffness in resistant hypertension?

The ambulatory arterial stiffness index (AASI) is a recently proposed index derived from 24-h ambulatory blood pressure monitoring (ABPM) for the evaluation of arterial stiffness. In this cross-sectional study we investigated whether AASI reflects arterial stiffness in patients with resistant hypertension by comparing AASI and ambulatory pulse pressure (PP) with aortic pulse wave velocity (PWV), a measure of arterial stiffness, in 391 resistant hypertensives. Clinical, laboratory and echocardiographic variables, 24-h ABPM and aortic PWV (measured using the Complior device) were obtained. AASI was calculated as 1--the regression slope of 24-h diastolic on systolic blood pressure (BP). Statistical analysis involved single and multiple linear regressions to assess the correlations between the two ABPM variables and PWV, both unadjusted and adjusted for potential confounders (age, gender, body height, presence of diabetes, 24-h mean arterial pressure [MAP], heart rate, and nocturnal BP reduction). Ambulatory PP and aortic PWV were independently associated with age, gender, presence of diabetes, and 24-h MAP, whereas AASI was associated with age, diabetes, and nocturnal diastolic BP reduction. PP showed stronger unadjusted (r=0.39, p<0.001) and adjusted (r=0.22, p<0.001) correlations with aortic PWV than AASI (r=0.12, p=0.032 and r= -0.04, p=0.47, respectively). In the analysis of subgroups stratified by gender, age, presence of atherosclerotic diseases and diabetes, dipping pattern, and ambulatory BP control, the superiority of PP over AASI was apparent in all subgroups. In conclusion, 24-h ambulatory PP was better correlated to arterial stiffness, as evaluated by aortic PWV, than the novel AASI, in patients with resistant hypertension.

Pulse pressure or dipping pattern: which one is a better cardiovascular risk marker in resistant hypertension?

OBJECTIVE

Nocturnal blood pressure (BP) reduction and ambulatory pulse pressure (PP) are well known prognostic markers obtained from ambulatory BP monitoring (ABPM). The aim of this study is to investigate which one of these ABPM parameters is related to high cardiovascular risk profile in resistant hypertension, based on their associations with target organ damage (TOD).

METHODS

Clinical-demographic, laboratory and ABPM variables were recorded in a cross-sectional study involving 907 resistant hypertensive patients. Nocturnal systolic BP reduction and 24-h PP were assessed both as continuous and dichotomized variables (PP at the upper tertile value: 63 mmHg). Statistical analyses included bivariate tests and multivariate logistic regression with each TOD as the dependent variable.

RESULTS

Patients with the nondipping pattern and high 24-h PP shared some characteristics: they were older, had higher prevalence of cerebrovascular disease and nephropathy, higher office and 24-h BP levels, increased serum creatinine and microalbuminuria, and higher left ventricular mass index than their counterparts. Additionally, patients with high PP had a greater prevalence of diabetes and other TOD. In multivariate logistic regression, high PP was independently associated with all TODs even after adjustment for sex, age, BMI, cardiovascular risk factors, 24-h mean arterial pressure and antihypertensive treatment, whereas nondipping pattern was only associated with hypertensive nephropathy. Furthermore, PP was more strongly associated with the number of TOD than the nocturnal systolic blood pressure (SBP) fall.

CONCLUSIONS

In a large group of resistant hypertensive patients, an increased 24-h PP shows a closer correlation with high cardiovascular risk profile than the nocturnal BP reduction.

Recent ventricular repolarization markers in resistant hypertension: are they different from the traditional QT interval?

BACKGROUND

Two electrocardiographic markers of ventricular repolarization abnormalities have been recently proposed: spatial T-wave axis deviation and T(peak)-T(end)-interval duration. The aim of this study was to evaluate these markers in patients with resistant hypertension, particularly their relationships with left ventricular mass (LVM) and geometric patterns, in comparison with the more traditional marker, the QTc interval.

METHODS

In a cross-sectional study, 810 resistant hypertensive patients were evaluated. Clinical, laboratory, electrocardiographic, 24-h blood pressures and echocardiographic variables were obtained. Maximum T(peak)-T(end)-interval duration (Tpe(max)) was considered prolonged if it was beyond the upper quartile value (120 ms), and the spatial T-wave axis on the frontal plane was considered abnormally deviated if >105 degrees or < 15 degrees . Statistical analysis involved bivariate tests, multivariate logistic regression and analysis of covariance.

RESULTS

Tpe(max)-interval prolongation, like QTc-interval prolongation, was found to be associated with body mass index, 24-h systolic blood pressure (SBP), indexed LVM, serum potassium, and heart rate. Abnormal T-axis deviation was associated with male gender, presence of coronary heart disease, serum creatinine, 24-h SBP, LVM, and serum potassium. All three repolarization parameters were shown to be associated with increased LVM, after adjustment for possible confounders. However, when included together into the same model, only abnormal T-axis and QTc-interval prolongation remained independently associated with LVM. All three parameters were also increased in patients with concentric hypertrophy geometric pattern.

CONCLUSIONS

Both the recently proposed repolarization parameters are associated with increased LVM and hypertrophy in patients with resistant hypertension, but only abnormal T-wave axis deviation appears to have distinct and additive relationships to the more classic marker, the QTc interval. Their prognostic values should be addressed in prospective studies .

Relation of left ventricular hypertrophy with systemic inflammation and endothelial damage in resistant hypertension

The relation between left ventricular hypertrophy (LVH) and unfavorable cardiovascular prognosis may involve systemic inflammation and endothelial dysfunction/damage. The aim of this study was to investigate in a cross-sectional design the relationships of LVH with C-reactive protein (CRP) levels (a marker of systemic low-grade inflammation) and with microalbuminuria (a marker of glomerular endothelial damage) in 705 patients with resistant hypertension. At baseline, all were submitted to a laboratory evaluation including 24-hour urinary albumin excretion, 2D echocardiogram, and 24-hour ambulatory blood pressure monitoring. A total of 463 patients also had high-sensitivity CRP levels determined. LVH was defined as an indexed left ventricular mass >110 g/m(2) in women and >125 g/m(2) in men. Microalbuminuria was evaluated in 3 categories: low normal (<15 mg/24 hours), high normal (between 15 and 29 mg/24 hours), and abnormal (between 30 and 299 mg/24 hours). CRP was dichotomized at the median value (3.7 mg/L). Associations with LVH were examined after adjustment for all of the potential confounders by multivariate logistic regression. A total of 534 patients (75.7%) had LVH. After full adjustment, both abnormal microalbuminuria (odds ratio: 1.97; 95% CI: 1.04 to 3.73) and high CRP (OR: 1.76; 95% CI: 1.06 to 2.93) were independently associated with LVH occurrence. The high-normal albuminuria was associated with a borderline significant 46% increased chance of having LVH. Furthermore, the association between high CRP and LVH was observed exclusively in the subgroup with normal albuminuria. In conclusion, both systemic inflammation and endothelial damage were associated with LVH occurrence. These relationships offer insight into the pathophysiological mechanisms linking LVH to atherosclerosis and to increased cardiovascular morbidity and mortality.

Clinical characteristics of resistant hypertension: the importance of compliance and the role of diagnostic evaluation in delineating pathogenesis

Resistant hypertension is defined as failure to achieve goal blood pressure despite adherence to 3 different antihypertensive medications, one of which must be a diuretic. True resistant hypertension must be distinguished by apparent resistant hypertension, of which an important cause is medication nonadherence, which can be recognized through a variety of monitoring strategies and may be improved through better patient education. A thorough history and examination should focus on evaluating for associated factors such as medication and illicit drug use, alcoholism, obesity, and obstructive sleep apnea. Further evaluation to differentiate apparent resistant hypertension from true resistant hypertension should include consideration of ambulatory blood pressure monitoring to rule out white coat hypertension. Routine laboratory work will reveal chronic kidney disease, which is the most common associated factor in resistant hypertension. Secondary or identifiable causes of resistant hypertension include primary aldosteronism, renovascular disease, and pheochromocytoma. Diagnostic evaluation for identifiable causes should be tailored for each patient and guided by signs and symptoms, as well as risks and benefits.

Das Herz bei arterieller Hypertonie

The term hypertensive heart disease covers the entities of left ventricular hypertrophy, microangiopathy and endothelial dysfunction resulting in diastolic and systolic dysfunction, arrhythmias and increased cardiovascular risk. From the pathophysiological point of view, this is caused by the hypertrophy of cardiac myocytes, interstitial fibrosis and media hypertrophy of the arterioles. Microangiopathy can be diagnosed as the earliest sign of hypertensive heart disease, with diastolic dysfunction also being found as an early change. In further persisting arterial hypertension left ventricular hypertrophy develops (often asymmetric) and later a systolic dysfunction. Clinically, the patients suffer from angina pectoris, dyspnea and rhythm disorders. Left ventricular hypertrophy is associated with an increased risk of malignant ventricular arrhythmias. Thus, the main therapeutic principle should be antihypertensive therapy with the goal of regression of hypertrophy leading to decreased mortality risk.