Role of Ivabradine in Patients with Heart Failure with Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) accounts for 50% of patients with heart failure. HFpEF carries almost similar morbidity and mortality outcomes to heart failure with reduced ejection fraction (HFrEF). Despite many trials, no management has been shown to improve mortality outcomes in HFpEF. An elevated heart rate in patients with HFpEF has been associated with worse outcomes. Previous trials on the use of beta-blockers in reducing the heart rate in patients with HFpEF have shown worse outcomes, possibly due to the negative inotropic effects. The funny current inhibitor, ivabradine, results in a reduced heart rate without affecting inotropy. Two randomized controlled trials and one cross-over study have evaluated the use of ivabradine in HFpEF patients. The outcomes of the trials have been heterogeneous; ivabradine showed improved exercise tolerance, no change in primary endpoints was seen l, and there was a worsening in the outcomes. Our review underscores the requirement of a large randomized clinical trial in the appropriate patient population.

Cardiac Function and Diastolic Dysfunction in Behcet's Disease: A Systematic Review and Meta-Analysis

Background. Cardiovascular involvement in Behcet's disease (BD) is reported and has variable manifestations. It is not clear if diastolic dysfunction (DD) is increased in BD. Our objective was to evaluate the existing literature to determine if cardiac dysfunction, particularly DD, was more prevalent in these patients. Methods. A systematic review and meta-analysis of the available studies analyzing the echocardiographic findings in BD was conducted using a random-effects model. Mean differences were used to calculate the effect sizes of the echocardiographic parameters of interest. Results. A total of 22 studies with 1624 subjects were included in the analysis. Patients with BD had statistically significantly larger mean left atrial dimension (0.08, p = 0.0008), greater aortic diameter (0.16, p = 0.02), significantly reduced ejection fraction (−1.08, p < 0.0001), significantly prolonged mitral deceleration time (14.20, p < 0.0001), lower E/A ratio (−0.24, p = 0.05), and increased isovolumetric relaxation time (7.29, p < 0.00001). Conclusion. DD is increased in patients with BD by the presence of several echocardiographic parameters favoring DD as compared to controls. The meta-analysis also identified that LA dimension is increased in BD patients. EF has also been found to be lower in BD patients. Aortic diameter was also increased in BD patients as compared to controls.

Reversibility of left ventricular mechanical dysfunction in patients with hypertensive heart disease

OBJECTIVE

Prior studies indicate that hypertension is associated with mechanical systolic dysfunction, even in the presence of a normal ejection fraction, but whether this cardiac dysfunction may be ameliorated by antihypertensive treatment is unknown.

METHODS

To test the hypothesis that mechanical systolic dysfunction in hypertension may respond to blood pressure-lowering therapy, we studied 182 patients with uncontrolled hypertension who underwent a 24-week trial of intensive versus standard antihypertensive therapy (titrated to a goal SBP <130 versus <140 mmHg) and had both baseline and follow-up echocardiography. We examined changes in left ventricular systolic function, reflected by systolic global longitudinal strain (GLS), in the entire cohort and in the subset of patients with systolic dysfunction at baseline (defined as GLS >-15%).

RESULTS

Despite all patients having a preserved left ventricular ejection fraction (≥50%), almost a third (32%) had mechanical systolic dysfunction at baseline. In the total sample, GLS significantly improved in response to antihypertensive therapy (-16.8 ± 3.8 to -18.7 ± 3.4%; P < 0.0001), and this improvement was especially evident in patients with baseline dysfunction (13.1 ± 2.2 to -17.0 ± 2.9%; P < 0.0001). Improvement in GLS was associated with lower BMI (P = 0.015) and was greater in women than in men (P = 0.003). Although uncorrelated with blood pressure change, GLS improvement was related to having received high doses of antihypertensive therapy during the study (P = 0.040).

CONCLUSION

In patients with hypertensive heart disease and normal left ventricular ejection fraction, abnormalities in left ventricular mechanical systolic function can be ameliorated in the setting of targeted antihypertensive treatment.

Age and the effectiveness of anti-hypertensive therapy on improvement in diastolic function

OBJECTIVE

Diastolic dysfunction is associated with adverse outcomes and is highly prevalent among older adults with hypertension. Lowering SBP with antihypertensive therapy has been shown to improve diastolic function, but whether or not age influences this effect is unknown.

METHODS

In the Exforge Intensive Control of Hypertension to Evaluate Efficacy in Diastolic Dysfunction trial, 189 patients (age range 45-93 years) with hypertension and diastolic dysfunction underwent echocardiography before and after 24 weeks of intensive versus standard antihypertensive therapy titrated to a goal SBP below 135 versus below 140  mmHg. We performed linear regression analyses to examine the association between age and improvement in diastolic function achieved with SBP reduction.

RESULTS

Antihypertensive therapy reduced SBP by 28 ± 19  mmHg overall, and this was not significantly different across age strata. However, percentage improvement in diastolic relaxation velocity (lateral E' peak velocity) for every 10  mmHg reduction in SBP was lower in older compared to younger patients. In analyses adjusting for age stratum, sex, treatment arm, baseline relaxation velocity, and baseline blood pressure, older age was associated with reduced improvement in diastolic relaxation velocity per 10  mmHg of SBP reduction (β -1.64, P = 0.009). In contrast, the degree of change in left ventricular mass index per 10  mmHg reduction in SBP was not influenced by age (P = 0.89).

CONCLUSIONS

In our sample of individuals with hypertension and diastolic dysfunction, older compared to younger adults experienced less improvement in diastolic function in response to similar reductions in SBP.

Impaired systolic function by strain imaging in heart failure with preserved ejection fraction

OBJECTIVES

This study sought to determine the frequency and magnitude of impaired systolic deformation in heart failure with preserved ejection fraction (HFpEF).

BACKGROUND

Although diastolic dysfunction is widely considered a key pathophysiologic mediator of HFpEF, the prevalence of concomitant systolic dysfunction has not been clearly defined.

METHODS

We assessed myocardial systolic and diastolic function in 219 HFpEF patients from a contemporary HFpEF clinical trial. Myocardial deformation was assessed using a vendor-independent 2-dimensional speckle-tracking software. The frequency and severity of impaired deformation was assessed in HFpEF, and compared to 50 normal controls free of cardiovascular disease and to 44 age- and sex-matched hypertensive patients with diastolic dysfunction (hypertensive heart disease) but no HF. Among HFpEF patients, clinical, echocardiographic, and biomarker correlates of left ventricular strain were determined.

RESULTS

The HFpEF patients had preserved left ventricular ejection fraction and evidence of diastolic dysfunction. Compared to both normal controls and hypertensive heart disease patients, the HFpEF patients demonstrated significantly lower longitudinal strain (LS) (-20.0 ± 2.1 and -17.07 ± 2.04 vs. -14.6 ± 3.3, respectively, p < 0.0001 for both) and circumferential strain (CS) (-27.1 ± 3.1 and -30.1 ± 3.5 vs. -22.9 ± 5.9, respectively; p < 0.0001 for both). In HFpEF, both LS and CS were related to LVEF (LS, R = -0.46; p < 0.0001; CS, R = -0.51; p < 0.0001) but not to standard echocardiographic measures of diastolic function (E' or E/E'). Lower LS was modestly associated with higher NT-proBNP, even after adjustment for 10 baseline covariates including LVEF, measures of diastolic function, and LV filling pressure (multivariable adjusted p = 0.001).

CONCLUSIONS

Strain imaging detects impaired systolic function despite preserved global LVEF in HFpEF that may contribute to the pathophysiology of the HFpEF syndrome. (LCZ696 Compared to Valsartan in Patients With Chronic Heart Failure and Preserved Left-ventricular Ejection Fraction; NCT00887588).

Effect of antihypertensive therapy on ventricular-arterial mechanics, coupling, and efficiency

AIMS

To investigate the effect of antihypertensive therapy on ventricular-arterial mechanics, coupling, and efficiency in early-stage hypertension.

METHODS AND RESULTS

We studied 527 participants from two clinical trials assessing the effect of blood pressure lowering on diastolic function. Participants were aged ≥45 years with early-stage hypertension, no heart failure, ejection fraction (EF) ≥50%, and diastolic dysfunction using Doppler echocardiography. Effective arterial afterload and its components were assessed along with measures of left ventricular (LV) structure and function prior to and after 24-38 weeks of antihypertensive therapy. Systolic blood pressure decreased from 154 ± 18 to 137 ± 15 mmHg at follow-up. Blood pressure reduction was associated with decreases in ventricular and arterial stiffness, improvements in systemic arterial compliance and resistance, enhanced LV ejection, and reduction in cardiac work (all P < 0.001). Changes in Ea/Ees ratio were inversely correlated with those in EF (r = -0.25; P < 0.001), stroke work index (r = -0.13; P = 0.007), and LV efficiency (r = -0.98; P < 0.001); and directly related to changes in mitral E/e' (r = 0.12; P = 0.01). Adjusting for age and blood pressure change, women and obese individuals had less enhancement in ventricular-arterial coupling and efficiency compared with men and non-obese individuals (P = 0.04 and 0.007, respectively).

CONCLUSION

Antihypertensive therapy reduces arterial and ventricular stiffness, enhances ventricular-arterial coupling, reduces cardiac work, and improves LV efficiency, systolic, and diastolic function. Attenuated responses in women and among obese subjects suggest that structure-function changes may be less reversible in these groups, possibly explaining their greater susceptibility to ultimately develop heart failure.

The relationship between renal impairment and left ventricular structure, function, and ventricular-arterial interaction in hypertension

OBJECTIVES

Our objective was to define the relationship between renal dysfunction--both albuminuria and reduced estimated glomerular filtration rate (eGFR)--and cardiac structure and diastolic dysfunction among patients with chronic hypertension.

METHODS

Both albuminuria and eGFR were measured in 540 asymptomatic patients with hypertension and diastolic dysfunction assessed by reduced early mitral annular relaxation velocity (E'). The majority of patients were white, mean age was 60 ± 10 years, mean SBP was 149 ± 18 mmHg, and there was a low prevalence comorbid conditions. Albuminuria was undetectable in 148 (27%), within the normal to low range [urine albumin-to-creatinine ratio (UACR) 1-25 mg/g for men, 1-17 mg/g for women] in 292 (54%), and high or very high (UACR >25 mg/g for men, >17 mg/g for women) in 100 (19%). Estimated GFR was 60 ml/min per 1.73 m² or less in 75 (14%), 61-90 ml/min per 1.73 m² in 244 (45%), and more than 90 ml/min per 1.73 m² in 221 (41%).

RESULTS

Albuminuria, even within the normal range, was associated with greater left ventricular wall thickness (P = 0.01), higher relative wall thickness (P = 0.004), worse diastolic function reflected in lower E' (P = 0.01), greater arterial and left ventricular end-systolic stiffness (P < 0.0001 and P = 0.003, respectively), and higher N-terminal pro-brain natriuretic peptide (NT-proBNP) level (P = 0.0025), even after adjustment for differences in baseline characteristics. In contrast, no independent relationship was observed between eGFR and parameters of cardiac structure or function.

CONCLUSION

Among asymptomatic hypertensive patients with evidence of diastolic dysfunction, the presence of albuminuria, even within the normal range, is associated with greater concentric remodeling, greater left ventricular end-systolic stiffness, and worse diastolic function.

Design and methods of the Pro-B Type Natriuretic Peptide Outpatient Tailored Chronic Heart Failure Therapy (PROTECT) Study

BACKGROUND

Serial measurements of N-terminal pro-B type natriuretic peptide (NT-proBNP) provide prognostic information in patients with chronic heart failure (HF). Changes in NT-proBNP concentrations parallel prognosis; however, it remains unclear whether HF care with a goal to maximize medical therapy and also lower NT-proBNP concentrations is superior to standard HF care alone.

AIMS

The aim of the study was to evaluate the hypothesis that an HF strategy guided by NT-proBNP reduces cardiovascular events compared to standard of care HF management.

METHODS

In a prospective randomized single-center trial, subjects with New York Heart Association class II to IV systolic HF (left ventricular ejection fraction < or =40%) will be enrolled. Both groups will receive standard HF management (with a goal for minimizing HF symptoms and achieving maximal dosages of therapies with proven mortality benefit in HF), whereas one group ("NT-proBNP") will also have treatment adjustments to reduce NT-proBNP concentrations < or =1,000 pg/mL. The primary end point of the trial is total cardiovascular events for a 1-year period; secondary end points will include effects of NT-proBNP-guided care on cardiac structure and function, quality of life, and total costs of care.

RESULTS

Enrollment began in 2006; of the original 300 planned, thus far, 151 subjects have been randomized. Interim analysis in November 2009 indicated significant reduction of events in the NT-proBNP arm. Full results are expected in 2010.

CONCLUSIONS

The Pro-B Type Natriuretic Peptide Outpatient Tailored Chronic Heart Failure Therapy (PROTECT) Study will test the hypothesis that therapy guided by NT-proBNP concentrations will be superior to standard of care HF management (www.clinicaltrials.gov identifier NCT00351390).

Effect of intensive versus standard blood pressure lowering on diastolic function in patients with uncontrolled hypertension and diastolic dysfunction

Diastolic dysfunction may precede development of heart failure in hypertensive patients. We randomized 228 patients with uncontrolled hypertension, preserved ejection fraction, and diastolic dysfunction to 2 targeted treatment strategies: intensive, with a systolic blood pressure target of <130 mm Hg, or standard, with a systolic blood pressure target of <140 mm Hg, using a combination of valsartan, either 160 or 320 mg, plus amlodipine, either 5 or 10 mg, with other antihypertensive medications as needed. Echocardiographic assessment of diastolic function was performed at baseline and after 24 weeks in a prospective, open-label, blinded end point design. Blood pressure was reduced significantly in both groups, from 161.2+/-13.9/90.1+/-12.0 to 130.8+/-12.3/74.9+/-9.1 mm Hg (P<0.0001) in the intensive arm and from 162.1+/-13.2/93.7+/-12.2 to 137.0+/-12.9/79.6+/-11.0 mm Hg (P<0.0001) in the standard arm (P<0.003 for between-group comparisons). Myocardial relaxation velocity improved from 7.6+/-1.1 to 9.2+/-1.7 cm/s (Delta 1.54+/-1.4 cm/s; P<0.0001) in the intensive arm and from 7.5+/-1.3 to 9.0+/-1.9 cm/s (Delta 1.48+/-1.6 cm/s; P<0.0001) in the standard arm, with no difference between the 2 strategies in the achieved improvement (P=0.58). The degree of improvement in annular relaxation velocity was associated with the extent of systolic blood pressure reduction, and patients with the lowest achieved systolic blood pressure had the highest final diastolic relaxation velocities.