Left ventricular midwall function improves with antihypertensive therapy and regression of left ventricular hypertrophy in patients with asymptomatic hypertension

Association between hypertensive urgencies and subsequent cardiovascular events in patients with hypertension

OBJECTIVE

To determine whether patients with hypertensive urgency have a higher risk for subsequent cardiovascular events compared with hypertensive patients without this event.

METHODS

Overall, 384 patients with hypertensive urgency and 295 control patients were followed up for at least 2 years. Hypertensive urgency was defined as a systolic blood pressure above 220 mmHg and/or a diastolic blood pressure above 120 mmHg without any evidence of acute end-organ damage. The control group consisted of patients admitted to the emergency department with a systolic blood pressure between 135 to 180 mmHg and a diastolic blood pressure between 85-110 mmHg. The number of cardiovascular events defined as acute coronary syndrome, acute stroke, atrial fibrillation, acute left ventricular failure and aortic aneurysm were consecutively analyzed during follow-up. The median follow-up time was 4.2 years (interquartile range 2.9-5.7 years). Twenty-six patients of the urgency group and 23 patients of the control group were lost for follow-up.

RESULTS

Overall, 117 (17%) patients had nonfatal clinical cardiovascular events and 13 had (2%) fatal cardiovascular events. The frequency of cardiovascular events was significantly higher in patients with hypertensive urgencies (88 vs. 42; P = 0.005). The Cox regression analysis identified age (P < 0.001) and hypertensive urgencies (P = 0.035) as independent predictors for subsequent cardiovascular events.

CONCLUSIONS

Hypertensive urgencies are associated with an increased risk for subsequent cardiovascular events in patients with arterial hypertension.

Prevalence and Correlates of Left Ventricular Hypertrophy in the African American Study of Kidney Disease Cohort Study

African Americans with hypertensive renal disease represent a high-risk population for cardiovascular events. Although left ventricular hypertrophy is a strong predictor of adverse cardiac outcome, the prevalence and associated factors of left ventricular hypertrophy in this patient population are not well described. The African American Study of Kidney Disease Cohort Study is a prospective, observational study that is an extension of the African American Study of Kidney Disease randomized clinical trial that was conducted from 1994 to 2001 in African Americans with hypertension and mild-to-moderate renal dysfunction. Echocardiograms and 24-hour ambulatory blood pressure monitoring were performed at the baseline visit of the cohort. Of 691 patients enrolled in the cohort study, 599 patients had interpretable baseline echocardiograms and ambulatory blood pressure data. Left ventricular hypertrophy was defined using a cut point for left ventricular mass index >49.2 g/m 2.7 in men and >46.7 m/m 2.7 in women. The majority of patients had left ventricular hypertrophy (66.7% of men and 73.9% of women). In a multiple regression analysis, higher average day and nighttime systolic blood pressure, younger age, and lower predicted glomerular filtration rate were associated with left ventricular hypertrophy, but albuminuria was not. These data demonstrate a striking prevalence of left ventricular hypertrophy in the African American Study of Kidney Disease Cohort and identify potential targets for prevention and therapeutic intervention in this high-risk patient population.

Cilnidipine Improves Left-Ventricular Midwall Function Independently of Blood Pressure Changes in Chinese Patients With Hypertension

Despite normal indices of left-ventricular (LV) chamber function, patients with hypertension are thought to have depressed LV midwall systolic shortening. This study was designed to investigate effects of short-term therapy with cilnidipine on LV midwall fractional shortening (mFS) in Chinese patients with hypertension. Thirty-seven patients with mild to moderate essential hypertension underwent a 2 week placebo run-in period, then received 5-10 mg/day of cilnidipine orally for 8 weeks. At the end of the placebo period and treatment, patients were examined by echocardiogram, measuring and calculating LV ejection fraction (EF), LV endocardial fraction shortening (eFS), and LV mFS. Compared with the normotensive group, the hypertensive group had a significantly higher eFS (P < 0.05) and EF (P < 0.01), both at the end of the placebo period and at 8 weeks; mFS of patients with hypertension was lower at the end of the placebo period (P < 0.05), but at the end of 8 weeks mFS was not different than that of the control group (P = 0.963). After cilnidipine treatment, EF and eFS did not change (P > 0.05); however, absolute mFS and corrected mFS were increased significantly (P < 0.01). Moreover, changes of mFS showed no correlation with changes of blood pressure (P > 0.05). Midwall fractional shortening is more reliable and sensitive than conventional systolic function measures in assessment of systolic function; cilnidipine can improve left-ventricular systolic function (mFS) independently of blood pressure changes in Chinese patients who have hypertension.

Hypertensive heart disease

Left ventricular hypertrophy (LVH) and diastolic dysfunction (CHF-D) are the early manifestations of cardiovascular target organ damage in patients with arterial hypertension and signify hypertensive heart disease. Identification of hypertensive heart disease is critical, as these individuals are more prone to congestive heart failure, arrhythmias, myocardial infarction and sudden cardiac death. Regression of left ventricular (LV) mass with antihypertensive therapy decreases the risk of future cardiovascular events. The goal of antihypertensive therapy is to both lower blood pressure (BP) and interrupt BP-independent pathophysiologic processes that promote LVH and CHF-D. The purpose of this review is to summarize current and emerging approaches to the pathophysiology and treatment of hypertensive heart disease.

Antihypertensive drugs and the heart

Left ventricular hypertrophy (LVH) and diastolic dysfunction (CHF-D) are early signs of cardiac end-organ damage (hypertensive heart disease) in patients with arterial hypertension. The presence of LVH or CHF-D confers increased risk of cardiovascular morbidity and mortality in patients with hypertension. Regression of left ventricular mass with antihypertensive therapy is associated with reduction in cardiovascular events. Antihypertensive therapy should be geared to both lower blood pressure and specifically reverse the pathophysiologic processes that may be independent of actual blood pressure. This review summarizes current and emerging approaches to the treatment of individuals with hypertensive heart disease.

RingTag: ring-shaped tagging for myocardial centerline assessment

RATIONALE AND OBJECTIVES

Although endocardial ejection indexes lead to overestimation of contractility in hypertrophied hearts, circumferential fiber shortening at the mid wall (cFS) is less affected by wall thickness. In this study magnetic resonance tagging is exploited to assess directly cFS in normal and hypertrophied hearts.

METHODS

A novel tagging procedure generates freely definable, convex ring saturation bands. Data acquisition during the cardiac cycle is achieved with a fast, single breath-hold echo-planar imaging measurement that is combined with a slice-following approach and a navigator-guided breath-holding technique to improve reproducibility of breath hold positions.

RESULTS

The procedure is able to create variably shaped convex saturation structures on the myocardium that can be tracked automatically throughout the cardiac cycle. Circumferential shortening at the endocardial border (FSendo) obtained in 6 healthy volunteers and in 6 patients with hypertensive cardiomyopathy suggested hypercontractility of hypertrophied hearts (30.7 +/- 4.1% vs. 43.9 +/- 4.4% respectively; P < 0.002), whereas shortening at the level of the myofibers assessed as cFS was not different (17.2 +/- 1.4% vs. 18.1 +/- 2.8% respectively; P = 0.49).

CONCLUSIONS

The presented approach allows for assessment of midwall myocardial mechanics and may become a useful tool to study contractile function in hypertrophied hearts.

Myocardial strain rate is a superior method for evaluation of left ventricular subendocardial function compared with tissue Doppler imaging

OBJECTIVES

This study was performed to evaluate subendocardial function using strain rate imaging (SRI).

BACKGROUND

The subendocardium and mid-wall of the left ventricle (LV) play important roles in ventricular function. Previous methods used for evaluating this function are either invasive or cumbersome. Strain rate imaging by ultrasound is a newly developed echocardiographic modality based on tissue Doppler imaging (TDI) that allows quantitative assessment of regional myocardial wall motion.

METHODS

We examined eight sheep using TDI in apical four-chamber views to evaluate the LV free wall. Peak strain rates (SRs) during isovolumic relaxation (IR), isovolumic contraction (IC), and myocardial strain were measured in the endocardial (End), mid-myocardial (Mid), and epicardial (Epi) layers. For four hemodynamic conditions (created after baseline by blood, dobutamine, and metoprolol infusion), we compared differences in SR of End, Mid, and Epi layers to peak positive and negative first derivative of LV pressure (dP/dt).

RESULTS

Strain rate during IC showed a good correlation with +dP/dt (r = 0.74, p < 0.001) and during IR with -dP/dt (r = 0.67, p = 0.0003). There was a significant difference in SR between the myocardial layers during both IC and IR (End: -3.4 +/- 2.2 s(-1), Mid: -1.8 +/- 1.5 s(-1), Epi: -0.63 +/- 1.0 s(-1), p < 0.0001 during IC; End: 2.2 +/- 1.5 s(-1), Mid: 1.0 +/- 0.8 s(-1), Epi: 0.47 +/- 0.64 s(-1), p < 0.0001 during IR). Also, SRs of the End and Mid layers during IC were significantly altered by different hemodynamic conditions (End at baseline: 1.7 +/- 0.7 s(-1); blood: 2.0 +/- 1.1 s(-1); dobutamine: 3.4 +/- 2.3 s(-1); metoprolol: 1.0 +/- 0.4 s(-1); p < 0.05). Myocardial strain showed differences in each layer (End: -34.3 +/- 12.6%; Mid: -22.6 +/- 12.1%; Epi: -11.4 +/- 7.9%; p < 0.0001) and changed significantly in different hemodynamic conditions (p < 0.0001).

CONCLUSIONS

Strain and SR appear useful and sensitive for evaluating myocardial function, especially for the subendocardial region.

Regression of left ventricular hypertrophy: are there preferred drugs?

The presence of left ventricular hypertrophy (LVH) confers markedly increased risk of cardiovascular morbidity and mortality in patients with hypertension. Regression of left ventricular (LV) mass with antihypertensive therapy is associated with reduction in cardiovascular events. In studies based on monotherapy, among the classes of antihypertensive drugs that have been adequately tested, diuretics and angiotensin-converting enzyme inhibitors appear to be the most effective agents for reducing LV mass. New avenues of research, based on combination antihypertensive therapy and on a more sophisticated understanding of the molecular mechanisms of LVH, may yield new pharmacologic approaches to regressing LV mass.

A meta-analysis of the effects of treatment on left ventricular mass in essential hypertension

PURPOSE

Antihypertensive medications have different effects on left ventricular mass. We conducted a meta-analysis of double-blind trials that measured the effects of antihypertensive therapy on left ventricular mass.

METHODS

Medical databases and review articles were screened for double-blind, randomized controlled trials (through September 2002) that reported the effects of diuretics, beta-blockers, calcium antagonists, angiotensin-converting enzyme (ACE) inhibitors, or angiotensin II receptor antagonists on echocardiographic left ventricular mass in essential hypertension. Treatment arms of the same drug class, weighted for the number of patients, were combined. Analysis of covariance was performed to detect differences among drug classes in effects on left ventricular structure.

RESULTS

Eighty trials with 146 active treatment arms (n = 3767 patients) and 17 placebo arms (n = 346 patients) were identified. Adjusted for treatment duration and change in diastolic blood pressure, there was a significant difference (P = 0.004) among medication classes: left ventricular mass index decreased by 13% with angiotensin II receptor antagonists (95% confidence interval [CI]: 8% to 18%), by 11% with calcium antagonists (95% CI: 9% to 13%), by 10% with ACE inhibitors (95% CI: 8% to 12%), by 8% with diuretics (95% CI: 5% to 10%), and by 6% with beta-blockers (95% CI: 3% to 8%). In pairwise comparisons, angiotensin II receptor antagonists, calcium antagonists, and ACE inhibitors were more effective at reducing left ventricular mass than were beta-blockers (all P <0.05 with Bonferroni correction).

CONCLUSIONS

Antihypertensive drug classes have different effects on left ventricular mass reduction. Whether a greater reduction of left ventricular mass results in better clinical outcomes remains to be determined.

Fixed combination trandolapril/verapamil sustained-release: a review of its use in essential hypertension

In well designed studies in patients with mild to moderate hypertension, combinations of the sustained-release (SR) formulation of the nondihydropyridine calcium channel antagonist verapamil 120 to 240 mg/day and the ACE inhibitor trandolapril 0.5 to 8 mg/day were significantly more effective in reducing sitting systolic blood pressure (SBP) and diastolic blood pressure (DBP) from baseline than placebo. In most randomised studies, combinations of verapamil SR 120 to 240 mg/day and trandolapril 0.5 to 8 mg/day were significantly more effective in lowering sitting DBP and SBP than the corresponding monotherapies administered at the same dosage. Trandolapril/verapamil SR 2/180 mg/day provided significantly more effective 24-hour ambulatory blood pressure (BP) control than of the corresponding monotherapies. Moreover, trandolapril/verapamil SR reduced BP in patients inadequately controlled with either of the corresponding monotherapies. The antihypertensive efficacy of trandolapril/verapamil SR 2/180 mg/day was generally similar to that of other combinations of antihypertensive agents (metoprolol/hydrochlorothiazide, atenolol/chlorthalidone, lisinopril/hydrochlorothiazide, enalapril/hydrochlorothiazide) in patients with hypertension, including those with type 2 diabetes mellitus. Trandolapril/verapamil SR reduced BP in patients with hypertension and type 2 diabetes or primary renal disease, Black patients and elderly patients. Trandolapril/verapamil SR was more effective than the individual components administered as monotherapy in reducing proteinuria in patients with type 2 diabetes or primary renal disease. Trandolapril/verapamil SR had a neutral or beneficial effect on metabolic parameters (glucose, insulin, lipids) in patients with hypertension, including those with type 2 diabetes. Trandolapril/verapamil SR preserved left ventricular function in patients with heart failure. Fewer cardiac events occurred after therapy with trandolapril/verapamil SR than after trandolapril alone in post-myocardial infarction patients with congestive heart failure. The incidence of adverse events in recipients of trandolapril/verapamil SR was similar to that of the individual components, and that of other combination therapies. In placebo-controlled trials conducted in the US, headache, upper respiratory tract infections, cough, constipation, atrioventricular block (first degree) and dizziness were the most commonly reported adverse events in recipients of combinations of verapamil SR (120 to 240 mg/day) and trandolapril (0.5 to 8 mg/day). In conclusion, the fixed-dose combination of trandolapril/verapamil SR is an effective treatment for patients with hypertension, including those with type 2 diabetes. Trandolapril/verapamil SR tended to be more effective than monotherapy with either verapamil SR or trandolapril, and generally showed antihypertensive efficacy similar to that of other combination antihypertensive therapies. Current data support the use of trandolapril/verapamil SR as an alternative treatment when monotherapy with either agent is not effective. Data from large clinical trials currently being conducted will assist in fully defining the role of trandolapril/verapamil SR as a cardio- and renoprotective agent.

Change in systolic left ventricular performance after 3 years of antihypertensive treatment: the Losartan Intervention for Endpoint (LIFE) Study

BACKGROUND

We have shown that hypertensive patients with left ventricular (LV) hypertrophy have decreased LV midwall mechanics, but the effect of antihypertensive therapy remains unclear.

METHODS AND RESULTS

Echocardiograms were recorded at baseline in 679 hypertensive patients and ECG LV hypertrophy and repeated yearly during 3 years of blinded treatment to achieve target blood pressures (BPs) of 140/90 mm Hg. On average, BP was reduced from 174+/-21 to 147+/-19 over 95+/-11 to 82+/-10 mm Hg and LV mass from 234+/-56 to 194+/-50 g. Endocardial fractional shortening (FS) decreased slightly, whereas midwall FS increased from 15.4+/-2.0% to 16.8+/-2.1% and stress-corrected midwall FS increased from 97+/-13 to 105+/-12% (all P<0.001). Change in midwall FS was related inversely to change in LV mass (LVM), relative wall thickness (RWT), and diastolic BP and directly to change in Doppler stroke volume (SV, all P<0.001). Multivariate analysis showed that change in MWS was independently inversely related to changes in LVM (beta=-0.211), RWT (beta=-0.334, all P<0.001), and diastolic BP (beta=-0.088, P<0.05) and directly related to SV (beta=0.192, P<0.001) with control for blinded therapy. Change in stress-corrected midwall shortening was inversely independently associated with changes in LVM (beta=-0.153) and RWT (beta=-0.562) and directly with changes in SV (beta=0.145) and systolic BP (beta=0.s221, all P<0.001) with control for blinded therapy.

CONCLUSIONS

Antihypertensive therapy reduced LVM and increased LV midwall shortening and contractility with a small decrease in LV chamber function and significant increase in SV. Change in systolic LV performance was independently associated inversely with change in LVM, RWT, and BP and directly with change in SV.

Left ventricular mass and systolic dysfunction in essential hypertension

A relation between left ventricular (LV) hypertrophy and depressed midwall systolic function has been described in hypertensive subjects. However, a strong confounding factor in this relation is concentric geometry, which is both a powerful determinant of depressed midwall systolic function and a correlate of LV mass in hypertension. To evaluate the independent contribution of LV mass to depressed systolic function, 1827 patients with never-treated essential hypertension (age 48 +/- 12 years, men 58%) underwent M-mode echocardiography under two-dimensional guidance. Relative wall thickness was the strongest determinant of low midwall fractional shortening (r = -0.63, P < 0.0001). The significant inverse relation observed between LV mass and midwall fractional shortening (r = -0.43, P < 0.0001) persisted after taking into account the effect of relative wall thickness (partial r = -0.27, P < 0.0001). Within each sex-specific quintile of relative wall thickness, prevalence of subnormal afterload-corrected midwall systolic function was greater in subjects with, than in subjects without, LV hypertrophy (P < 0.05 for the first, third, fourth and fifth quintile). In a multiple linear regression analysis, both LV mass (P < 0.0001) and relative wall thickness (P < 0.0001) were independent predictors of a reduced midwall fractional shortening. In conclusion, the inverse association between LV mass and midwall systolic function is partly independent from the effect of relative wall thickness. LV hypertrophy is a determinant of subclinical LV dysfunction independently of the concomitant changes in chamber geometry.

Diastolic function in hypertension

Diastolic dysfunction in patients with hypertension may present as asymptomatic findings on noninvasive testing, or as fulminant pulmonary edema, despite normal left ventricular systolic function. Up to 40% of hypertensive patients presenting with clinical signs of congestive heart failure have normal systolic left ventricular function. In this article we review the pathophysiologic factors affecting diastolic function in individuals with diastolic function, current and emerging tools for measuring diastolic function, and current concepts regarding the treatment of patients with diastolic congestive heart failure.

Effects of antihypertensive agents on the left ventricle: clinical implications

Hypertensive heart disease (HHD) is characterized by left ventricular hypertrophy (LVH), alterations of cardiac function, and coronary flow abnormalities. LVH is an independent cardiovascular risk factor related to cardiovascular complications in patients with hypertension. Therefore, a decrease in left ventricular mass is a therapeutic goal in these patients. The effect of the different antihypertensive agents on LVH regression has been studied in nearly 500 clinical trials. Most studies conclude that there is regression of LVH after significant decrease in blood pressure with most commonly prescribed antihypertensive agents. However, the ability to regress LVH is different between antihypertensive drug classes. ACE inhibitors and calcium channel antagonists are more potent in reducing left ventricular mass than beta-blockers, with diuretics falling in the intermediate group. Recent data suggest that angiotensin AT(1) receptor antagonists reduce left ventricular mass to a similar extent as ACE inibitors or calcium channel antagonists. Although a large number of studies have established that reversal of LVH decreases the occurrence of adverse cardiovascular events in patients with hypertension, the hypothesis that LVH regression is beneficial has not yet been conclusively proven. On the other hand, the time has come to revisit the current management of HHD simply focused on controlling blood pressure and reducing left ventricular mass. In fact, it is necessary to develop new approaches aimed to repair myocardial structure and protect myocardial perfusion and function and, in doing so, to reduce in a more effective manner, adverse risk associated with HHD. The identification of genes involved in both the process of HHD and the response to therapy may be critical for the development of these new approaches. This article will review briefly the available data on the effects of antihypertensive agents on HHD. In addition, the emerging new concepts on the pharmacology of hypertensive myocardial remodeling and the pharmacogenetic basis of the treatment of HHD will be also considered.