Prognostic significance of serial changes in left ventricular mass in essential hypertension

Effect of left ventricular hypertrophy on long-term survival of patients with coronary artery disease following percutaneous coronary intervention

The impact of left ventricular hypertrophy (LVH) on survival among patients with established coronary artery disease (CAD) is not well understood. We sought to evaluate the effect of LVH on the survival of patients with CAD following percutaneous coronary intervention (PCI). Three hospitals in New York City contributed prospectively defined data on 4284 consecutive patients undergoing PCI. Allcause mortality at a mean follow-up of three years was the primary endpoint. LVH was present in 383 patients (8.9%). LVH patients had a greater prevalence of hypertension (88% vs. 68%, p<0.001), vascular disease (21% vs. 6.6%, p=0.001), and prior heart failure (10% vs. 5.5%, p<0.001). LVH patients presented less often with one-vessel disease (38% vs. 50%, p=0.040) and more often with two- (34% vs. 29%, p=0.014) or three-vessel (22% vs. 18%, p=0.044) disease. Ejection fractions and angiographic success were similar in both groups. In-hospital mortality did not differ between groups. At three-year follow-up, the survival rate for patients with LVH was 86% vs. 91% in patients without LVH (log-rank p=0.001). However, after adjustment for differences in baseline characteristics using Cox proportional hazards analysis, LVH was found not to be an independent predictor of mortality (hazard ratio, 0.93; 95% confidence interval, 0.68–1.28; p=0.67). We conclude that LVH at the time of PCI is not independently associated with an increase in the hazard of death at three years.

The impact of left ventricular hypertrophy on early and long-term survival after coronary artery bypass grafting

BACKGROUND

Left ventricular hypertrophy (LVH) can itself contribute to increased rates of cardiovascular events. We sought to determine the impact of LVH on in-hospital and long-term mortality after coronary artery bypass grafting (CABG).

METHODS

Between 1992 and 2003, 4140 consecutive patients underwent CABG. Long-term survival data (mean follow-up 7.0 years) were obtained from the National Death Index. The impact of LVH on in-hospital mortality was determined by multivariate logistic regression analysis. Patients with and without LVH were compared by Cox proportional hazard models and risk-adjusted Kaplan-Meier curves.

RESULTS

There were 977 patients (23.6%) with LVH. Their mean EuroSCORE was 7.4 +/- 3.4 and there were 40 in-hospital deaths (4.1%) in this group. Multivariate logistic regression showed that patients with LVH had less elective operations, higher Canadian Cardiovascular Society Functional Class, more previous myocardial infarctions and higher percentages of 3-vessel disease, hypertension, current congestive heart failure, malignant ventricular arrhythmias, chronic obstructive pulmonary disease, calcified aorta, low ejection fraction, intravenous nitroglycerine, previous percutaneous coronary interventions and smoking. After adjustment for all available pre, intra and postoperative variables LVH was not an independent predictor for in-hospital mortality (OR 1.04, 95% CIs 0.60-1.81, P = 0.891). Risk-adjusted Kaplan-Meier survival curves showed decreased long-term survival in patients with LVH after the first 3 years (HR 1.24, 95% CIs 1.06-1.44, P = 0.006).

CONCLUSIONS

Patients with LVH showed similar in-hospital mortality when compared with patients without LVH. However, LVH was a detrimental risk factor for late mortality, especially after the third postoperative year. These data suggest the need for a more frequent long-term follow-up among patients with LVH undergoing CABG.

Determination of left ventricular mass on cardiac computed tomographic angiography

RATIONALE AND OBJECTIVES

Left ventricular hypertrophy (LVH) is associated with an increased risk of cardiac death. The present study evaluates whether using computed tomographic (CT)-derived criteria for normal myocardial mass can improve detection of LVH on CT angiography (CTA).

MATERIALS AND METHODS

A total of 2238 subjects (63 +/- 9 years, 27% female) who underwent CTA were studied. To identify normal limits for CT-derived myocardial mass, we studied normal subjects (those without diabetes, hypertension, congestive heart failure, or coronary artery disease). Left ventricular mass (LVM) was measured manually using two different workstations. The CT criteria of LVH was defined as LVM above the 97th percentile per gender and compared to echocardiographic criteria (110 g/m(2) in women; 124 g/m(2) in men), and specificity and sensitivity of both models to detect LVH were calculated.

RESULTS

The LVM was higher in men than women in normal cohorts (75.5 +/- 14.0 vs. 63.1 +/- 12.8 g/m(2), P = .001 with electron beam CTA and 78.5 +/- 11.9 vs. 65.0 +/- 9.2 g/m(2), P = .001 with 64 multidetector [MD] CT, respectively). The coefficient of variation between electron beam CTA and 64 MDCT for measuring LVM was 3.1%. Comparing the new CTA/64 MDCT criteria of LVH (103.0 g/m(2) in men; 89.0 g/m(2) in women) to the previous echocardiographic criteria of LVH, the specificity in women and men decreased from 100% in both genders by echocardiography to 91.8% and 92.6%, respectively, but the sensitivity increased from 42.0% to 100% and from 41.1% to 100%.

CONCLUSION

This study suggests that CT-measured LVM has low variability and normal values based on CT criteria will potentially increase the early detection of LVH.

Hypoadiponectinemia in lipodystrophic HIV individuals: a metabolic marker of subclinical cardiac damage

BACKGROUND AND AIM

To evaluate cardiovascular abnormalities in highly active antiretroviral therapy (HAART) treated HIV patients with no signs or symptoms of cardiovascular impairment, and to assess the relative role of multiple concomitant risk factors.

METHODS AND RESULTS

Forty-four consecutive HIV subjects (mean age 41+/-6 yrs) were enrolled. Inclusion criteria were HIV infection, CD4+cell count>150/ml, HAART treatment for at least 4 years. Metabolic serum levels, morphological and functional echocardiographic parameters were assessed in all subjects. Sixteen healthy age and sex matched subjects with no cardiovascular risk factors were recruited as controls. HIV patients showed increased left ventricular mass index with reduced mid-wall fractional shortening (mFS) when compared to controls (50.2+/-10.5 vs. 38.6+/-14.4, p=0.05 and 18.3+/-0.6 vs. 21.9+/-0.7, p<0.05, respectively). Twenty-nine patients were lipodystrophic (LD) and showed a longer HAART period (p=0.0004) and greater use of protease inhibitors (PI) (p=0.001). Coronary flow reserve (CFR) was significantly reduced in HIV patients as compared to controls (p<0.0001), as it was in LD subjects when compared to non-lipodystrophic ones (NLD) (p<0.001). Adiponectin concentrations were found to be significantly lower in LD subjects than in NLD ones (7.8+/-0.8 vs. 13.8+/-1.2 microg/ml, p=0.01), and showed a direct correlation with CFR. In multiple regression analysis, insulin, HDL and adiponectin accounted for 63% of CFR variations.

CONCLUSIONS

Left ventricular hypertrophy, depressed mFS and reduced CFR represent the main signs of subclinical cardiac damage in HIV subjects treated with HAART. Hypoadiponectinemia in these subjects seems to be a metabolic risk factor of cardiovascular impairment.

Relation of plasma midregional proatrial natriuretic peptide to target organ damage in adults with systemic hypertension

We tested the hypothesis that, in adults with essential hypertension, plasma levels of midregional proatrial natriuretic peptide (MR-proANP) are associated with target organ damage. MR-proANP is a newly described stable fragment of N-terminal proatrial natriuretic peptide. Participants included 1,919 adults with hypertension identified from the community (1,037 African-Americans, 65 +/- 9 years of age, 72% women; 882 non-Hispanic whites, 61 +/- 9 years of age, 55% women). We measured MR-proANP by an immunoluminometric assay. Measurements of target organ damage included the ankle-brachial index (ABI), urinary albumin-creatinine ratio (UACR), and left ventricular (LV) mass (available only in African-Americans). Generalized estimating equations were used to assess whether plasma MR-proANP was associated with measurements of target organ damage, independent of potential confounding variables. In African-Americans, higher MR-proANP was significantly associated with lower ABI (p <0.0001), higher UACR (p <0.0001), and greater LV mass (indexed to height to the power of 2.7, p <0.0001). After adjustment for age, gender, body mass index, systolic blood pressure, estimated glomerular filtration rate, smoking history, diabetes mellitus, total and high-density lipoprotein cholesterols, medication (blood pressure lowering, statin, and aspirin) use, and previous myocardial infarction or stroke, higher MR-proANP levels remained significantly associated with lower ABI (p = 0.01), higher UACR (p = 0.0007), and greater LV mass index (p <0.0001). In non-Hispanic whites, higher MR-proANP levels were significantly associated with lower ABI (p = 0.002) and greater UACR (p = 0.001), but not after adjustment for the covariates listed earlier. In conclusion, plasma MR-proANP may be a marker of target organ damage in the setting of hypertension, especially in African-Americans.

Muscle ring finger 1 mediates cardiac atrophy in vivo

Pathological cardiac hypertrophy, induced by various etiologies such as high blood pressure and aortic stenosis, develops in response to increased afterload and represents a common intermediary in the development of heart failure. Understandably then, the reversal of pathological cardiac hypertrophy is associated with a significant reduction in cardiovascular event risk and represents an important, yet underdeveloped, target of therapeutic research. Recently, we determined that muscle ring finger-1 (MuRF1), a muscle-specific protein, inhibits the development of experimentally induced pathological; cardiac hypertrophy. We now demonstrate that therapeutic cardiac atrophy induced in patients after left ventricular assist device placement is associated with an increase in cardiac MuRF1 expression. This prompted us to investigate the role of MuRF1 in two independent mouse models of cardiac atrophy: 1) cardiac hypertrophy regression after reversal of transaortic constriction (TAC) reversal and 2) dexamethasone-induced atrophy. Using echocardiographic, histological, and gene expression analyses, we found that upon TAC release, cardiac mass and cardiomyocyte cross-sectional areas in MuRF1(-/-) mice decreased approximately 70% less than in wild type mice in the 4 wk after release. This was in striking contrast to wild-type mice, who returned to baseline cardiac mass and cardiomyocyte size within 4 days of TAC release. Despite these differences in atrophic remodeling, the transcriptional activation of cardiac hypertrophy measured by beta-myosin heavy chain, smooth muscle actin, and brain natriuretic peptide was attenuated similarly in both MuRF1(-/-) and wild-type hearts after TAC release. In the second model, MuRF1(-/-) mice also displayed resistance to dexamethasone-induced cardiac atrophy, as determined by echocardiographic analysis. This study demonstrates, for the first time, that MuRF1 is essential for cardiac atrophy in vivo, both in the setting of therapeutic regression of cardiac hypertrophy and dexamethasone-induced atrophy.

ARB candesartan and CCB amlodipine in hypertensive patients: the CASE-J trial

The Candesartan Antihypertensive Survival Evaluation in Japan (CASE-J) trial was a comparative study of the angiotensin II receptor blocker (ARB), candesartan, and a calcium channel blocker (CCB), amlodipine, regarding the incidence of cardiovascular events in high-risk Japanese hypertensive patients. The study design was a prospective, multicenter, randomized, open-label, active-controlled, two-arm, parallel-group comparison study with a response-dependent dose titration and blinded assessment of the end point. The CASE-J trial enrolled 4728 patients, with a mean age of 63.8 years and a mean BMI of 24.6 kg/m(2), who were randomly assigned to either candesartan- or amlodipine-based treatment regimens. Blood pressure was well controlled to the level of less than 140/80 mmHg in both of the treatment regimens. During 3.2 years of follow-up, primary cardiovascular events occurred in 134 patients in each of the two treatment-based regimens, resulting in no significant difference in the incidence of cardiovascular events between them (hazard ratio: 1.01; 95% confidence interval: 0.79-1.28; p = 0.969). In 404 patients with left ventricular hypertrophy, a significantly larger decrease in left ventricular mass index 3 years after enrollment was observed in candesartan-based (n = 205) than amlodipine-based (n = 199) regimens (-22.9 vs -13.4 g/m(2), respectively; p = 0.023). Furthermore, new-onset diabetes occurred in fewer patients taking candesartan than in those taking amlodipine, resulting in a 36% relative risk reduction (p = 0.030). The CASE-J trial demonstrated that both an ARB, candesartan, and a CCB, amlodipine, equally suppressed the incidence of cardiovascular events. The ARB may confer more beneficial effects to hypertensive patients with left ventricular hypertrophy or for those at-risk of diabetes than CCB.

Management of hypertension in patients with left ventricular hypertrophy

Left ventricular hypertrophy (LVH) is a cardinal manifestation of organ damage in patients with arterial hypertension. Identifying LVH is a fundamental step in evaluating hypertensive patients, because clinical and epidemiologic studies have shown this condition has a strong independent adverse prognostic significance. LVH is an integrated marker of cardiovascular risk, reflecting hypertension's hemodynamic and nonhemodynamic effects on the heart. Reversing LVH is an intermediate goal of antihypertensive therapy. Pharmacologic strategies to reverse LVH should be based on combining two or more drugs: a renin-angiotensin system blocker (ie, angiotensin-converting enzyme inhibitor or angiotensin receptor antagonist), and a calcium antagonist or low-dose diuretic. Successful therapeutic plans should also include nonpharmacologic interventions to promote LVH regression.

A short duration of high-fat diet induces insulin resistance and predisposes to adverse left ventricular remodeling after pressure overload

Insulin resistance is an increasingly prevalent condition in humans that frequently clusters with disorders characterized by left ventricular (LV) pressure overload, such as systemic hypertension. To investigate the impact of insulin resistance on LV remodeling and functional response to pressure overload, C57BL6 male mice were fed a high-fat (HFD) or a standard diet (SD) for 9 days and then underwent transverse aortic constriction (TAC). LV size and function were assessed in SD- and HFD-fed mice using serial echocardiography before and 7, 21, and 28 days after TAC. Serial echocardiography was also performed on nonoperated SD- and HFD-fed mice over a period of 6 wk. LV perfusion was assessed before and 7 and 28 days after TAC. Nine days of HFD induced systemic and myocardial insulin resistance (assessed by myocardial 18F-fluorodeoxyglucose uptake), and myocardial perfusion response to acetylcholine was impaired. High-fat feeding for 28 days did not change LV size and function in nonbanded mice; however, TAC induced greater hypertrophy, more marked LV systolic and diastolic dysfunction, and decreased survival in HFD-fed compared with SD-fed mice. Compared with SD-fed mice, myocardial perfusion reserve was decreased 7 days after TAC, and capillary density was decreased 28 days after TAC in HFD-fed mice. A short duration of HFD induces insulin resistance in mice. These metabolic changes are accompanied by increased LV remodeling and dysfunction after TAC, highlighting the impact of insulin resistance in the development of pressure-overload-induced heart failure.

Determinants of left ventricular mass and presence of metabolic risk factors in normotensive individuals

BACKGROUND

Insulin resistance and obesity are recognized as left ventricular (LV) mass determinants independent of blood pressure (BP). Prevalence of LV hypertrophy (LVH) and the relationship between LV mass to body composition and metabolic variables were evaluated in normotensive individuals as participants of a population-based study.

METHODS

LV mass was measured using the second harmonic image by M-mode 2D guided echocardiography in 326 normotensive subjects (mean 47+/-9.4 years). Fasting serum lipids and glucose, BP, body composition and waist circumference (WC) were recorded during a clinic visit.

RESULTS

Applying a normalization criterion not related to body weight (g/height raised to the power 2.7) and the cut-off points of 47.7 (men) and 46.6 g/m(2.7) (women), LVH was found in 7.9% of the sample. Univariate analysis showed LV mass (g/m(2.7)) related to age, body mass index (BMI), WC, fat and lean body mass, systolic and diastolic BP, and metabolic variables (cholesterol, HDL-c, triglycerides and glucose). In multivariate analysis only BMI and age-adjusted systolic BP remained as independent predictors of LV mass, explaining 31% and 5% of its variability. Removing BMI from the model, WC, age-adjusted systolic BP and lean mass remained independent predictors, explaining 25.0%, 4.0% and 1.5% of LV mass variability, respectively. After sex stratification, LV mass predictors were WC (8%) and systolic BP (5%) in men and WC (36%) and systolic BP (3%) in women.

CONCLUSION

BMI in general and particularly increased abdominal adiposity (WC as surrogate) seems to account for most of LV mass increase in normotensive individuals, mainly in women.

Effects of fixed combination of lisinopril plus hydrochlorothiazide on regression of left ventricular hypertrophy in patients with essential hypertension: an opened, multi-centre, prospective clinical trial

The aim of this trial was to examine the effects of antihypertensive fixed combination of lisinopril plus hydrochlorothiazide (Lopril H, Bosnalijek dd, Bosnia and Herzegovina) on regression of left ventricular hypertrophy in patients with essential arterial hypertension. We included 297 patients in our trial, aged 54.65+/-9.6 years, with treated or untreated hypertension and with high risk of cardiac events, in an opened trial of therapy based on lisinopril plus hydrochlorothiazide. Patients from five European countries were followed up for a period of 12 weeks. Duration of treatment was 12 weeks. We adjusted daily doses of lisinopril plus hydrochlorothiazide after every clinical examination and recorded adverse effects of drugs. In the beginning and after 12 weeks of treatment, 277 patients (93.2%) underwent 2-dimensional echocardiography and there were 186 patients evaluated for efficacy of treatment on left ventricular hypertrophy (LVH). We recorded a regression of index mass LVH (168.56 vs 161.51 g/m2, P<0.0001), and regression was something more in women vs men. We recorded average reduction of left ventricular mass index for patients with LVH (N=186) by 7.05 g/m2 (4.18%) in all patients, by 6.73 g/m2 (3.93%) in men and 7.27 g/m2 (4,37%) in women. The proportion of patients who attained a regression of left ventricular mass tended to be greater in men (54.55% vs 53.21%). This research has proved regression of LVH in more than 53% patients after using fixed combination of lisinopril plus hydrochlorothiazide.

Differences in left ventricular hypertrophy and dysfunction between patients with cerebral hemorrhage and those with cerebral infarction

Left ventricular (LV) hypertrophy and dysfunction due to hypertension have been established as risk markers for stroke in hypertensive patients. The purpose of this study was to examine the differences in LV hypertrophy and dysfunction between patients with cerebral hemorrhage and those with cerebral infarction. The study enrolled 23 hypertensive patients with cerebral infarction, 25 hypertensive patients with cerebral hemorrhage, and 24 normotensive controls (controls). Standard echocardiography was performed; LV mass index was measured to evaluate LV hypertrophy, and conventional diastolic transmitral flow velocities were measured to assess LV diastolic function, which was also evaluated by measuring mitral annular velocities using tissue Doppler echocardiography. The Tei index, which reflects both the diastolic and systolic function of LV, was also calculated. The LV mass index and Tei index were significantly higher in cerebral hemorrhage (116 +/- 38 g/m(2) and 0.57 +/- 0.13) than those in controls (92 +/- 20 g/m(2) and 0.46 +/- 0.10) (p < 0.05). In contrast, the LV mass index and Tei index in cerebral infarction (100 +/- 27 g/m(2) and 0.46 +/- 0.12) were not different from those in controls. Thus, the Tei index was significantly worse in the patients with cerebral hemorrhage than in those with cerebral infarction (p < 0.05). On the other hand, the parameters, which reflect diastolic function, showed no significant differences between cerebral hemorrhage and cerebral infarction. These results indicate that LV hypertrophy and dysfunction due to hypertension are more apparent in patients with cerebral hemorrhage than in those with cerebral infarction.

Treatment of heart failure with preserved systolic function

Heart failure is a major public health problem. Heart failure with preserved systolic function (HF-PSF) is a common form, which is difficult to diagnose. Results of recent studies show that HF-PSF has a poor prognosis, with an annual survival rate similar to that of heart failure with left ventricular systolic dysfunction. Despite these findings, the therapeutic management of HF-PSF is not clearly defined. We will discuss in this review of the literature the current therapeutic management of HF-PSF, including the role of precipitating factors such as hypertension, myocardial ischaemia and supraventricular arrhythmias, and the main results of epidemiological registries and randomized controlled clinical trials in this disease. Only four large therapeutic trials have assessed the impact of different classes of drugs (digoxin, angiotensin II converting enzyme inhibitors, angiotensin II receptors type I blockers and beta-blockers) on morbidity and mortality in HF-PSF. Results of these trials are disappointing. Apart from the beta-blockers, the other three classes of drugs did not show benefit on the outcome of the disease. Moreover, the results of the beta-blocker trial are controversial as a mixed population of heart failure with and without preserved systolic function was studied. Finally, the current therapeutic management of patients with HF-PSF is still based on our pathophysiological knowledge: education, low salt diet, diuretics, slowing heart rate and controlling triggering factors. Other large randomized controlled multicenter trials, which may help us in the understanding of HF-PSP and its therapeutic management, are ongoing.

Left ventricular papillary muscles and trabeculae are significant determinants of cardiac MRI volumetric measurements: Effects on clinical standards in patients with advanced systolic dysfunction

BACKGROUND

Left ventricular (LV) mass and ejection fraction are of diagnostic and therapeutic importance in patients with systolic dysfunction. Cardiac MRI (CMR) has been proposed as a standard for these indices. Prior studies have variably included papillary muscles and trabeculae in either intracavitary or myocardial volumes. Quantitative effects and clinical implications of this methodological difference in patients with systolic dysfunction are unknown.

METHODS

Fifty consecutive patients with known systolic dysfunction (EF<40%) underwent CMR. LV volumes were determined using previously established methods: Method 1 included papillary muscles and trabeculae in cavity volume, method 2 included these in myocardial volume. Both methods were used for each patient with tracings superimposed to isolate papillary/trabecular volume and insure consistency of other endocardial contours. Readers applied methods in random order blinded to clinical findings and results of the other method.

RESULTS

LV mass differed substantially by method (p<0.001) with absolute difference of 16.6%. Ejection fraction differed by 3 points (p<0.001) with absolute differences of > or =5 points in 16% of patients. Mean differences in LV mass and ejection fraction were produced by consistent methodological differences on a per-patient basis. Methodology used produced differences in patients meeting established criteria for LV hypertrophy (28% vs. 60%, p<0.001) and ICD implantation (64% vs. 48%, p<0.01).

CONCLUSIONS

LV mass and ejection fraction differ significantly between commonly employed CMR methods. Alternative inclusion of papillary muscles and trabeculae in either cavity or myocardial volumes produces significant differences in clinical and therapeutic indices that can affect management of patients with advanced systolic dysfunction.

Reference values for quantitative left ventricular and left atrial measurements in cardiac computed tomography

To assess reference values for left ventricular (LV) and left atrial (LA) dimensions, global LV function, and LV-myocardial mass for cardiac CT. We examined 120 subjects undergoing a coronary angiography using 64-slice and dual-source CT. All individuals had a low cardiovascular risk, normal ECG, negative biomarkers, and a normal cardiac CT examination. All subjects had a negative medical history of cardiovascular disease both on admission and at clinical 6-month follow-up. The following measurements were obtained: septal wall thickness (SWT), posterior wall thickness (PWT), LV inner diameter (LVID), LA anterior posterior diameter (LAD(sys)), end-systolic volume (ESV), and end-diastolic volume (EDV), LV-myocardial mass (LVMM). We found significant gender-related differences for all LV dimensions (SWT(sys), SWT(dia),PWT(sys),PWT(dia),LVID(sys),LVID(dia)). LAD(sys) showed no significant difference between males and females. Significant differences were found for global LV functional parameters including ESV, EDV, and SV, whereas no significant differences were found for the EF. LV-myocardial mass parameters showed significant gender-related differences. No significant correlation was found between any of these parameters and age. All data were transferred to percentile ranks. This study provides gender-related reference values and percentiles for LV and LA quantitative measurements for cardiac CT and should assist in interpreting results.

The prognostic value of the ECG in hypertension: where are we now?

In hypertension, the presence of left ventricular hypertrophy (LVH) is associated with increased risk of both cardiovascular morbidity and mortality. To date, the electrocardiogram (ECG) remains the cornerstone of LVH diagnosis in clinical practice because it is universally available, technically easy to perform and highly specific. In the most recent European Society of Hypertension/European Society of Cardiology guidelines for the treatment of arterial hypertension, the Sokolow-Lyon voltage criterion was recommended as part of all routine assessment of subjects with hypertension. However, the use of the ECG in the diagnosis of LVH is somewhat limited by its poor sensitivity. In this review article, we discuss the individual strength and weaknesses of the commonly used ECG criteria in diagnosing LVH. In addition, we present the latest data on the prognostic significance of ECG LVH and the survival differences conferred in different genders. In view of the recent Losartan Intervention for Endpoint Reduction in Hypertension trial, the prognostic benefit of LVH regression will also be addressed. Finally, with the wider availability of echocardiography, the role of combining both modalities to improve risk stratification in hypertension is reviewed.

Regression of echocardiographic left ventricular hypertrophy after 2 years of therapy reduces cardiovascular risk in patients with essential hypertension

BACKGROUND

There is still ambiguity about the prognostic relevance of regression of left ventricular hypertrophy (LVH) (as revealed by echocardiography) in a large population of subjects with hypertension, with and without evidence of LVH in their electrocardiograms (ECGs). This holds true even after adjusting for various confounders including in treatment ambulatory blood pressure (BP). The most suitable time point for a follow-up echocardiography also remains a matter for debate. In this study, we investigated the prognostic relevance of regression of LVH after 2 years of therapy, in a large population of subjects with hypertension, and possessing the aforesaid characteristics.

METHODS

The occurrence of adverse cardiovascular events was evaluated in 387 patients with LVH shown by echocardiography at baseline, and these patients were studied again after 2 years of therapy. At the second examination, 245 subjects showed regression of LVH, whereas 142 did not.

RESULTS

During the time period before the subsequent follow up (6.2 +/- 3 years, range 1.9-12.9 years), 59 first adverse events (26 cardiac and 33 cerebrovascular) had occurred among these subjects. The event rates per 100 patient-years in patients with and without LVH regression were 1.06 and 4.4, respectively. After adjusting for several covariates at the 2-year visit, including in treatment ambulatory BP, Cox regression analysis showed that cardiovascular risk was significantly lower in patients with LVH regression than in those without (RR 0.36, 95% CI 0.19-0.68, P = 0.002). When left ventricular (LV) mass index reduction was analyzed instead of LVH status, it was found to be significantly associated with reduced risk (RR 0.62 per 1-s.d. decrease, 95% CI 0.44-0.88, P = 0.01).

CONCLUSIONS

Regression of LVH, as revealed by echocardiography after 2 years of therapy, is associated with reduced cardiovascular risk in patients with hypertension, whether or not LVH was revealed in their ECGs. This holds true even after adjusting for various confounders including in treatment ambulatory BP.

Studies on left ventricular hypertrophy regression in arterial hypertension: a clear message for the clinician?

BACKGROUND

Evidence-based medicine should provide clear and unbiased information to clinicians. We conducted an analysis on published randomized trials evaluating the effects of antihypertensive therapy on left ventricular (LV) morphology assessed by echocardiography to investigate (i) the consistency of criteria used for definition of LV hypertrophy (LVH) and (ii) the consistency of the way LVH regression and blood pressure (BP) control were reported.

METHODS

Studies identified by a PubMed search were eligible for inclusion in the analysis, if they fulfilled the following criteria: (i) publication in a peer-reviewed journal within the last 12 years; (ii) double blind, randomized, controlled, parallel-group design; (iii) numerosity of at least 50 adult hypertensive subjects; (iv) follow-up duration of at least 6 months; (v) comparison between single-drugs or association regimens; (vi) LV mass (LVM) or wall thickness measured by echocardiography.

RESULTS

Thirty-nine trials, including 9,162 hypertensive subjects of both genders in 78 active treatment arms or in 6 placebo arms were identified. Definition of LVH was provided by 34 studies (87.1%) according to 19 different criteria. All trials evaluated LVH regression as the absolute or relative changes of continuous variables such as LVM index (LVMI) or LV wall thickness. Data concerning prevalence rates of LVM normalization were reported in 12 studies (30.7%). The percentage of patients reaching BP target (<140/90 mm Hg) was reported in 11 studies (28.2%).

CONCLUSIONS

Our findings indicate that (i) definition of hypertensive LVH phenotype is extremely variable, and (ii) no precise information on LVH regression rates or changes in LV geometrical patterns, as well as on target BP, is provided by the majority of papers.

Early detection and management of the high-risk patient with elevated blood pressure

Severe or important blood pressure elevations are associated with the risk of cardiovascular disease. However, a significant proportion of myocardial infarctions and strokes occur in subjects with only slight elevations or even with normal blood pressure. Both the coexistence of other cardiovascular risk factors, such as diabetes or dyslipidemia, or those recently recognized, such as elevations of C-reactive protein or abdominal obesity and metabolic syndrome, or the presence of target organ damage, such as microalbuminuria, left ventricular hypertrophy, mild renal dysfunction or increased intima-media thickness, all indicate the existence of a high cardiovascular risk in mild hypertensives or in subjects with normal or high-normal blood pressure. Unfortunately, these high-risk patients are often not recognized and thus under-treated. The 2003 European Societies of Hypertension and Cardiology guidelines emphasize the importance of a complete risk assessment and stratification in subjects at all blood pressure categories. The search for other cardiovascular risk factors and target organ damage should be encouraged. Identification of these high-risk patients may allow an earlier indication for antihypertensive treatment and for correction of all cardiovascular risk factors. The objective would be to impair the progression or to induce the regression of silent vascular damage before a clinical event develops.

Electrocardiographic left ventricular hypertrophy regression induced by an angiotensin receptor blocker-based regimen in daily clinical practice: the SARA study

AIM

Clinical trials have proved that angiotensin receptor blockers (ARB) are more effective than other antihypertensive agents in reducing left ventricular hypertrophy (LVH); however, information about the efficacy of ARB on LVH regression in daily medical practice is scarce. The aim of the SARA study was to investigate the effect of an ARB on electrocardiographic LVH (ECG-LVH) in a hypertensive outpatient population attending clinical practice.

METHODS

From 276 recruited patients with mild-to-moderate essential hypertension (245 uncontrolled, 31 newly diagnosed), 264 (age: 62.9+/-11.6 years; 51.2% women) completed the study and were valid for the analysis. The patients were treated for a 12-month period with a candesartan-based regimen [(8/16 mg+hydrochlorothiazide 12.5 mg+additional drugs to target BP<140/90 mmHg (<130/80 in diabetics)]. ECG changes were measured at a core laboratory and Cornell product (CorP), Sokolow-Lyon product (SokP) and QRS duration (QRSd) criteria were determined.

RESULTS

At baseline, 27.4% of patients fulfilled the criteria of LVH by CorP. The proportion of patients with ECG-LVH by CorP criteria decreased to 21.1% at the end of the study, relative risk reduction (RRR) was 22.9%, P<0.001. When using SokP the percentage of ECG-LVH reduced from 24.1 to 21.7% (RRR 9.6%, P=0.1). Quantitatively, CorP was reduced by 84.4 mmxms [95% confidence interval (CI): -8.14, -160.66; P=0.03]; a greater reduction was detected in obese patients (P<0.05), diabetics (P<0.07) and patients with baseline ECG-LVH (P<0.05). In the multivariate analysis, female gender, baseline systolic blood pressure, baseline CorP and QRSd values were the main predictive factors for ECG-LVH regression.

CONCLUSION

The SARA study demonstrates that a candesartan-based regimen reduces ECG-LVH in the hypertensive population attending daily in clinical practice.

Pioglitazone shift circadian rhythm of blood pressure from non-dipper to dipper type in type 2 diabetes mellitus

BACKGROUND

Insulin resistance significantly correlated with a non-dipper type of essential hypertension. Thiazolidinediones (TZD), oral hypoglycaemic agents that act as insulin sensitizers, have been demonstrated in multiple in vivo and in vitro studies to possess antihypertensive properties. This study examined the efficacy of TZD therapy with pioglitazone at transforming the circadian rhythms of blood pressure from a non-dipper to a dipper type.

MATERIALS

We examined 31 patients with type 2 diabetes mellitus during both a baseline period and a period of treatment with pioglitazone. Patients received 15 mg day(-1) pioglitazone for four weeks and 30 mg day(-1) for 12 weeks. Twenty-four hour ambulatory blood pressure monitoring (ABPM) and laboratory data (blood tests for cardiovascular risk factors) were obtained at the beginning and end of the study.

RESULTS

In non-dippers (n = 16), but not dippers (n = 15), we observed a significant interaction between pioglitazone therapy and nocturnal falls in systolic and diastolic blood pressure. This examination indicated that the magnitude of the nocturnal blood pressure fall was affected by pioglitazone therapy. In non-dippers, but not dippers, a significant correlation was observed between the percent decrease in nocturnal BP and the homeostasis model assessment (HOMA) index (r = 0.774, P = 0.0007).

CONCLUSIONS

The present study demonstrated that pioglitazone can restore the nocturnal BP declines in parallel to reductions in the HOMA index, suggesting that insulin resistance may play an important role in the genesis of circadian BP rhythms. TZD-based treatment may thus have the additional therapeutic advantage of reducing the risk of cardiovascular complications by transforming the circadian rhythm of BP.

QT peak prolongation is not associated with left ventricular hypertrophy in teenage professional football players

OBJECTIVE

QT peak prolongation is associated with left ventricular hypertrophy (LVH) in patients with hypertension. This study tests the hypothesis that QT peak prolongation correlates with LV mass index in apparently healthy young football players.

METHODS

QT peak and other ECG criteria for LVH were assessed in 117 male professional footballers (mean age 16.4 years +/- SD 0.76). Their left ventricular mass index (LVMI) was assessed by transthoracic echocardiography. Heart rate-corrected QT peak (QTpc) interval was measured in lead I using Bazett's formula. Spearman (2-tailed) test and UNIANOVA was used to assess if there were correlations between QT peak and the various echocardiographic and ECG indices of LVH.

RESULTS

Echocardiographic LVH, defined as LVMI > or = 134 g/m(2), was seen in 79 (70.5%) subjects. ECG-defined LVH was present in 54 (50 %) players by Sokolow-Lyon criteria, in 19 (16 %) players by Romhilt Score, in 5 (4 %) players by Cornell voltage criteria, and in 7 (6 %) players by Cornell product >2436 mm ms. There was no correlation between QT peak (QTpc) and LVMI on echocardiography (Spearman r = 0.058, 2-tailed P = 0.54). In addition, there was no relation between LVH and QTpc of lead I using any of the following ECG criteria: Sokolow-Lyon (P = 0.6), Romhilt (P = 0.3), Cornell voltage (P = 0.8), or Cornell product (P = 0.6).

CONCLUSION

QT peak interval, which is associated with pathological LVH in hypertensive patients and is a measure of risk of cardiac death, does not correlate with LVH characterized by myocyte hypertrophy in young apparently healthy professional footballers.

Cardiac repolarization and its relation to ventricular geometry and rate in reverse remodelling during antihypertensive therapy with irbesartan or atenolol: results from the SILVHIA study

Hypertensive left ventricular (LV) hypertrophy is associated with a substantial risk for malignant arrhythmias and sudden death. According to recent results, antihypertensive therapy with the angiotensin II type 1 receptor blocker irbesartan reverses both structural and electrical remodelling. However, the relation between the LV geometric pattern (concentric vs eccentric) and electrical reverse remodelling has not been characterized, neither has the relation between repolarization and rate (QT/RR and JT/RR relation), which presumably reflects the propensity for bradycardia-dependent ventricular arrhythmia. In this study, repeat echocardiographic and electrocardiographic measurements were performed in hypertensive patients with LV hypertrophy, randomized to double-blind therapy with irbesartan (n = 44) or the beta(1)-adrenoceptor blocker atenolol (n = 48) for 48 weeks; 53 patients had concentric and 39 eccentric LV hypertrophy. In addition, 37 matched hypertensive subjects without LV hypertrophy and no current therapy served as controls. Irbesartan induced structural and electrophysiological reverse remodelling, independent of LV geometry. In contrast, atenolol had similar beneficial effect only in patients with concentric LV hypertrophy, while the response in those with eccentric hypertrophy was unfavourable with both prolonged repolarization time and an increased QT/RR slope (suggesting reverse-use dependence). In conclusion, there is a significant geometry-related difference in the reverse remodelling processes induced by irbesartan and atenolol. Echocardiographic characterization of the geometry in hypertension-induced LV hypertrophy might become an important step in the selection of optimal antihypertensive therapy.

Heart failure and cardiac hypertrophy

Left ventricular failure is the final common pathway for a wide spectrum of myocardial insults, including systemic hypertension and myocardial infarction. Although left ventricular hypertrophy is an adaptive response to pressure and volume overload, this process becomes maladaptive if left untreated and pathologic cardiac hypertrophy then becomes an important and independent risk factor for the development of heart failure. Despite its importance, the transition from hypertrophy to heart failure in humans is poorly understood. The focus of treatment should be prevention of heart failure and other cardiovascular events, such as stroke and atrial fibrillation. When heart failure is present, treatment with medical and device therapy is then focused on improving functional capacity, increasing survival, and preventing progression to end-stage heart failure.

[Abnormal patterns of diurnal blood pressure variation and cardiovascular remodeling in elderly hypertensive patients]

Hypertension causes left ventricular hypertrophy and increases in large artery stiffness with ageing, both of which are cardiovascular risks. We studied cardiovascular remodeling in elderly hypertensive patients by measuring blood brain natriuretic peptide (BNP), left ventricular mass indices (LVMI), pulse wave velocities (PWV), and ambulatory blood pressures. We focused on ageing and sex-differences. Both LVMI and PWV correlated significantly with nocturnal blood pressures, which in turn correlated with BNP levels. Thus, BNP might be a candidate for a surrogate endpoint of target organ damage in elderly cases of hypertension. Left ventricular hypertrophy progressed with ageing more in women. Systolic blood pressures in women were shown to rise abruptly after menopause and to surpass those in men. However, more non-dippers were observed in men, suggesting that the absolute value of nocturnal blood pressure is a determinant of left ventricular hypertrophy. PWV accelerated with ageing, but it did not correlate with LVMI, suggesting that progression of cardiac remodeling with ageing was relatively independent of vascular remodeling. Finally, the greater mortality in elderly women might be associated with progressive left ventricular hypertrophy.

Cardiomyocyte-restricted restoration of nitric oxide synthase 3 attenuates left ventricular remodeling after chronic pressure overload

Although nitric oxide synthase (NOS)3 is implicated as an important modulator of left ventricular (LV) remodeling, its role in the cardiac response to chronic pressure overload is controversial. We examined whether selective restoration of NOS3 to the hearts of NOS3-deficient mice would modulate the LV remodeling response to transverse aortic constriction (TAC). LV structure and function were compared at baseline and after TAC in NOS3-deficient (NOS3−/−) mice and NOS3−/− mice carrying a transgene directing NOS3 expression specifically in cardiomyocytes (NOS3−/−TG mice). At baseline, echocardiographic assessment of LV dimensions and function, invasive hemodynamic measurements, LV mass, and myocyte width did not differ between the two genotypes. Four weeks after TAC, echocardiographic and hemodynamic indexes of LV systolic function indicated that contractile performance was better preserved in NOS3−/−TG mice than in NOS3−/− mice. Echocardiographic LV wall thickness and cardiomyocyte width were greater in NOS3−/− mice than in NOS3−/−TG mice. TAC-induced cardiac fibrosis did not differ between these genotypes. TAC increased cardiac superoxide generation in NOS3−/−TG but not NOS3−/− mice. The ratio of NOS3 dimers to monomers did not differ before and after TAC in NOS3−/−TG mice. Restoration of NOS3 to the heart of NOS3-deficient mice attenuates LV hypertrophy and dysfunction after TAC, suggesting that NOS3 protects against the adverse LV remodeling induced by prolonged pressure overload.

Characterization of a model to independently study regression of ventricular hypertrophy

BACKGROUND

Although a host of studies catalogue changes that occur with the development of left ventricular hypertrophy (LVH), there is little information about features related solely to LVH regression. This is due, in part, to a lack of animal models to study this question. While traditional models of aortic banding have provided useful information regarding the development of LVH, a similarly effective model is necessary to study mechanisms associated with LVH regression.

MATERIALS AND METHODS

Minimally invasive transverse arch banding was performed in C57BL6 mice using a slipknot technique. Twenty-eight days later, the band was removed. Carotid Doppler velocity gradients were serially measured to assess the degree of aortic constriction. Echocardiography, histology, electron microscopy, and real-time polymerase chain reaction were used to assess functional, structural, and genetic aspects of hypertrophy.

RESULTS

Banding of the transverse arch created the expected increase in aortic velocity and gradient between the left and right carotid artery, which normalized with relief of the constriction. Pressure overload resulted in a robust hypertrophic response as assessed by heart weight/body weight ratios, gross and microscopic histology, transthoracic echocardiography, electron microscopy, and hypertrophy gene expression. These markers were reversed within 1 week following debanding and were maintained for up to 4 weeks. Mortality rate for the cumulative procedure was 5% over a 2-month period.

CONCLUSIONS

These results demonstrate a safe, effective, and reproducible method of promoting LVH regression-avoiding the need for endotracheal intubation, mechanical ventilation, and a second invasive surgery to remove the constriction. The simplicity of this technique combined with the well-known advantages of using the mouse species makes this model both unique and relevant. Ultimately, this model will facilitate focused study of independent mechanisms involved with LVH regression.

Update on the Management of Hypertension: Recent Clinical Trials and the JNC 7

The following issues are highlighted: Emphasis is placed on the importance of systolic blood pressure elevations in estimating risk and in determining prognosis. A review of placebo-controlled clinical trials indicates that cardiovascular events are statistically significantly reduced with diuretic- or b blocker-based treatment regimens. The question of whether blood pressure lowering alone or specific medications make the difference in outcome is discussed. Based on the results of numerous trials, it is apparent that blood pressure lowering itself is probably of greater importance in reducing cardiovascular events than the specific medication used. Meta-analyses suggest, however, that the use of an agent that blocks the renin-angiotensin aldosterone system is probably more effective in diabetics and in patients with nephropathy than a regimen based on calcium channel blocker therapy. The Antihypertensive and Lipid-Lowering treatment to Prevent Heart Attack Trial (ALLHAT) reported no overall difference in coronary heart disease outcome among patients treated with a diuretic-based compared to a calcium channel blocker- or an angiotensin-converting enzyme inhibitor-based treatment program. However, patients in the diuretic group experienced fewer episodes of heart failure than in the calcium channel blocker group and fewer episodes of heart failure and strokes than those in the angiotensin-converting enzyme inhibitor group. Results were similar in diabetics and nondiabetics. Possible reasons for this outcome are discussed. The Australian National Blood Pressure 2 study, which was unblinded, reported a marginally significantly better outcome only in male patients receiving an angiotensin-converting enzyme inhibitor-based regimen compared to those receiving a diuretic-based program. Finally, the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) is reviewed. Highlights of this report include the new designation of prehypertension, i.e., blood pressures of 120-139 mm Hg/80-89 mm Hg. The JNC 7 suggested that diuretics should be the first-step drug of choice in most patients, but listed numerous specific reasons why other agents should be used in special situations. The report stressed that the majority of patients will require two or more medications to achieve goal blood pressure.

Left Ventricular Geometric Patterns After 1 Year of Antihypertensive Treatment

Left ventricular hypertrophy increases the risk for cardiovascular target organ damage, myocardial infarction, and stroke. The authors assessed the patterns of ventricular adaptation in 107 essential hypertensives whose treatment had been withdrawn and its modification after 1 year of hypertension treatment. Blood pressure decreased from 158+/-17/96+/-12 mm Hg to 137+/-15/83+/-10 mm Hg (mean +/- SD; p<0.001); 45% of the patients (49 of 107) had their blood pressure controlled below 140 mm Hg and 90 mm Hg. Although a significant decrease of left ventricular mass index was found in the study, the percentage of patients with normal left ventricular geometry at the completion of the study increased by only 9% (27% to 36%, p>0.05). Left ventricular mass geometry improved in 31% of the patients, remained unaffected in 51%, and worsened in 18%. The data suggest that even while suboptimal antihypertensive treatment reduces left ventricular mass index, either left ventricular hypertrophy or concentric remodeling remains present in a significant number of patients at the end of a 1-year treatment period. The authors conclude that these patients should be considered as a subgroup at high risk and should be treated more aggressively.

Cardiac response to pressure overload in 129S1/SvImJ and C57BL/6J mice: temporal- and background-dependent development of concentric left ventricular hypertrophy

Left ventricular hypertrophy (LVH), a risk factor for cardiovascular morbidity and mortality, is commonly caused by essential hypertension. Three geometric patterns of LVH can be induced by hypertension: concentric remodeling, concentric hypertrophy, and eccentric hypertrophy. Clinical studies suggest that different underlying etiologies, genetic modifiers, and risk of mortality are associated with LVH geometric patterns. Since pressure overload-induced LVH can be modeled experimentally using transverse aortic constriction (TAC) and since C57BL/6J (B6) and 129S1/SvImJ (129S1) strains, which have different baseline cardiovascular phenotypes, are commonly used, we conducted serial echocardiographic studies to assess cardiac function up to 8 wk of post-TAC in male B6, 129S1, and B6129F1 (F1) mice. B6 mice had an earlier onset and more pronounced impairment in contractile function, with corresponding left and right ventricular dilatation, fibrosis, change in expression of hypertrophy marker, and increased liver weights at 5 wk of post-TAC. These observations suggest that B6 mice had eccentric hypertrophy with systolic dysfunction and right-sided heart failure. In contrast, we found that 129S1 and F1 mice delayed transition to decompensated heart failure, with 129S1 mice exhibiting preserved systolic function until 8 wk of post-TAC and relatively mild alterations in histology and markers of hypertrophy at 5 wk post-TAC. Consistent with concentric hypertrophy, our results show that these strains manifest different cardiac responses to pressure overload in a time-dependent manner and that genetic susceptibility to initial concentric hypertrophy is dominant to eccentric hypertrophy. These results also imply that genetic background differences can complicate interpretation of TAC studies when using mixed genetic backgrounds.

Left ventricular (LV) geometry and dipping state are determinants of LV mass reduction with angiotensin-converting enzyme inhibitor antihypertensive treatment

OBJECTIVES

Left ventricular hypertrophy is a major risk predictor in hypertensive patients and its regression is beneficial in terms of prognosis. The aim of this observational, open-labeled study was to investigate the effect of left ventricular geometry and dipping pattern on left ventricular mass reduction after chronic treatment with angiotensin-converting enzyme inhibitors, in a large population of hypertensive patients.

METHODS

We evaluated untreated patients with mild to moderate essential hypertension, before and 6 months after treatment with angiotensin-converting enzyme inhibitor monotherapy or angiotensin-converting enzyme inhibitor-low-dose thiazide combination. Left ventricular mass index, relative wall thickness and geometry pattern were derived from echocardiography. Dipping state was determined with 24-h ambulatory blood pressure monitoring at enrollment.

RESULTS

Overall, left ventricular mass index decrease in the 1400 patients (mean age 52.5 years) who completed the study was 12.9% of baseline value (P<0.00001). After adjusting for pretreatment value, left ventricular mass index reduction was similar with all angiotensin-converting enzyme inhibitors used [P= NS (not significant)], but it was higher in nondippers than dippers (14.1 vs. 12.3%, P<0.0001) and in patients with than without baseline left ventricular hypertrophy (14.6 vs. 11.3%, P<0.0001). We observed a stepwise augmentation of left ventricular mass index decrease with worsening left ventricular geometry (P<0.001). In multivariable analysis, impaired left ventricular geometry and blunted nocturnal blood pressure fall before treatment were independent predictors of a high left ventricular mass index reduction after treatment, independent of blood pressure fall, pretreatment left ventricular mass index, and other potential confounders.

CONCLUSION

In essential hypertension, left ventricular geometry and dipping state are independent determinants of left ventricular mass reduction with angiotensin-converting enzyme inhibitor treatment. All angiotensin-converting enzyme inhibitors are efficient in decreasing left ventricular mass.

Cardiac hypertrophy induced by sustained β-adrenoreceptor activation: pathophysiological aspects

Cardiac hypertrophy is promoted by adrenergic over-activation and represents an independent risk factor for cardiovascular morbidity and mortality. The basic knowledge about mechanisms by which sustained adrenergic activation promotes myocardial growth, as well as understanding how structural changes in hypertrophied myocardium could affect myocardial function has been acquired from studies using an animal model of chronic systemic beta-adrenoreceptor agonist administration. Sustained beta-adrenoreceptor activation was shown to enhance the synthesis of myocardial proteins, an effect mediated via stimulation of myocardial growth factors, up-regulation of nuclear proto-oncogenes, induction of cardiac oxidative stress, as well as activation of mitogen-activated protein kinases and phosphatidylinositol 3-kinase. Sustained beta-adrenoreceptor activation contributes to impaired cardiac autonomic regulation as evidenced by blunted parasympathetically-mediated cardiovascular reflexes as well as abnormal storage of myocardial catecholamines. Catecholamine-induced cardiac hypertrophy is associated with reduced contractile responses to adrenergic agonists, an effect attributed to downregulation of myocardial beta-adrenoreceptors, uncoupling of beta-adrenoreceptors and adenylate cyclase, as well as modifications of downstream cAMP-mediated signaling. In compensated cardiac hypertrophy, these changes are associated with preserved or even enhanced basal ventricular systolic function due to increased sarcoplasmic reticulum Ca(2+) content and Ca(2+)-induced sarcoplasmic reticulum Ca(2+) release. The increased availability of Ca(2+) to maintain cardiomyocyte contraction is attributed to prolongation of the action potential due to inhibition of the transient outward potassium current as well as stimulation of the reverse mode of the Na(+)-Ca(2+) exchange. Further progression of cardiac hypertrophy towards heart failure is due to abnormalities in Ca(2+) handling, necrotic myocardial injury, and increased myocardial stiffness due to interstitial fibrosis.

Relationship between central sympathetic drive and magnetic resonance imaging-determined left ventricular mass in essential hypertension

BACKGROUND

Sympathetic activation has been implicated in the development of left ventricular hypertrophy (LVH). However, the relationship between sympathetic activation and LV mass (LVM) has not been clearly defined across a range of arterial pressure measurements. The present study was planned to determine that relationship, using cardiac magnetic resonance imaging to accurately quantify LVM, in hypertensive patients with and without LVH and in normal subjects.

METHODS AND RESULTS

Twenty-four patients with uncomplicated and untreated essential hypertension (LVH[-]) were compared with 25 patients with essential hypertension and left ventricular hypertrophy (LVH[+]) and 24 normal control subjects. Resting muscle sympathetic nerve activity was quantified as multiunit bursts and single units. Cardiac magnetic resonance imaging-determined LVM was indexed to body surface area (LVM index); in the LVH[-] group, LVM index was 67+/-2.1 g/m2, a value between those of the LVH[+] (91+/-3.4 g/m2) and normal control (57+/-2.2 g/m2) groups, respectively. The sympathetic activity in the LVH[-] group (53+/-1.3 bursts per 100 cardiac beats and 63+/-1.6 impulses per 100 cardiac beats) was between (at least P<0.001) those of the LVH[+] (66+/-1.7 bursts per 100 cardiac beats and 77+/-2.2 impulses per 100 cardiac beats) and normal control (39+/-3.0 bursts per 100 cardiac beats and 45+/-3.4 impulses per 100 cardiac beats) groups. Significant positive correlation existed between sympathetic activity and LVM index in the LVH[-] and LVH[+] groups (at least r=0.76, P<0.0001) but not in the normal control group. However, no consistent relationship existed between arterial blood pressure and sympathetic activity or LVM index.

CONCLUSIONS

These findings further support the hypothesis that central sympathetic activation is associated with the development of LVH in human hypertension.

Left ventricular hypertrophy is present in one-half of newly-diagnosed peripheral arterial disease patients

OBJECTIVES

Peripheral arterial disease (PAD) patients are at high risk of cardiac death. Coincidental but silent coronary disease is obviously a major contributor but left ventricular hypertrophy (LVH) could be a second major contributor.

METHODS

To investigate whether LVH could really be making a large contribution to cardiac death in PAD, we assessed the prevalence of LVH when PAD was first diagnosed.

RESULTS

The prevalence of echo LVH when left ventricular mass was indexed to body surface area was 50%. Although office blood pressure and 24-h blood pressure were both significantly higher in those with LVH, in clinical practice, a contemporaneous blood pressure measurement (office or 24 h) at the time of PAD diagnosis would only partially identify those with LVH. For example, an office blood pressure cut-off of < 140/90 mmHg was found in 27% of all LVH cases and a 24-h blood pressure cut-off of < 125/80 mmHg was found in 24% of all LVH cases.

CONCLUSION

In conclusion, there is already a high prevalence of LVH in patients at first diagnosis of PAD. LVH is therefore common enough in PAD patients to potentially make a major contribution to cardiac death, which means that future research should now investigate whether screening for and regressing LVH when present would actually reduce cardiac deaths over and above merely achieving target blood pressure.

Angiotensin-converting enzyme inhibitors influence left ventricular mass and function independently of the antihypertensive effect

In our retrospective study, we evaluated whether ACE inhibitors can influence left ventricular (LV) morphofunctional characteristics in essential hypertension independently of the antihypertensive effect. We studied 21 hypertensive patients (group 1) before and after at least 18 months of treatment with ACE inhibitors that did not induce any blood pressure (BP) reduction; as a control group, we evaluated 19 hypertensive patients (group 2) not treated with antihypertensive drugs during the same period. At baseline, the 2 groups, neither one previously treated with antihypertensive drugs, were not significantly different with regard to sex, age, body mass index, 24-hour BP, and heart rate; LV mass index was similar between the groups, whereas LV diastolic indices were significantly lower in group 1. At the second evaluation, body mass index, 24-hour BP, and heart rate were unchanged in both groups; LV mass index was significantly decreased in group 1 and increased in group 2. LV diastolic parameters were significantly improved in group 1, whereas in group 2, diastolic function was significantly deteriorated. In conclusion, our clinical study shows that ACE inhibitors can induce LV hypertrophy regression and improvement of diastolic function also in the absence of any antihypertensive effect.