Losartan improves exercise tolerance in patients with diastolic dysfunction and a hypertensive response to exercise

Chronic Use of Antihypertensive Medications and Peak Exercise Blood Pressure in Adult Men and Women from the BALL ST Cohort

PURPOSE

To determine if individuals chronically (>1 yr) prescribed antihypertensive medications have a normal BP response to peak exercise compared with unmedicated individuals.

METHODS

Participants included 2555 adults from the Ball State Adult Fitness Longitudinal Lifestyle STudy cohort who performed a peak treadmill exercise test. Participants were divided into groups by sex and antihypertensive medication status. Individuals prescribed antihypertensive medications for >1 yr were included. Exaggerated and blunted SBP within each group was categorized using the Fitness Registry and the Importance of Exercise: A National Database (FRIEND) and absolute criteria as noted by the American Heart Association.

RESULTS

The unmedicated group had a greater prevalence ( P < 0.05) of blunted SBP responses, whereas the medicated group had a higher prevalence ( P < 0.05) of exaggerated SBP responses using both the FRIEND and absolute criteria. Peak SBP was higher ( P < 0.01) in medicated compared with unmedicated participants in the overall cohort when controlling for age and sex, but not after controlling for resting SBP ( P = 0.613), risk factors ( P = 0.104), or cardiorespiratory fitness ( P = 0.191). When men and women were assessed independently, peak SBP remained higher in the medicated women after controlling for age and resting SBP ( P = 0.039), but not for men ( P = 0.311). Individuals on beta-blockers had a higher peak SBP even after controlling for age, sex, risk factors, and cardiorespiratory fitness ( P = 0.022).

CONCLUSIONS

Individuals on antihypertensive medications have a higher peak SBP response to exercise. Given the prognostic value of exaggerated peak SBP, control of exercise BP should be considered in routine BP assessment and in the treatment of hypertension.

Excessive Blood Pressure Rise and Cardiovascular Remodeling in Marathon Runners

Exercise-induced hypertension (EIH) is thought to be associated with increased cardiovascular (CV) risks. However, no previous studies have investigated the effects of EIH on CV systems in marathon runners without CV risk factors using both 24-hr ambulatory blood pressure (BP) monitoring and exercise stress echocardiography (ESE). This study firstly described differences in CV adaptations according to EIH assessed by both exams. Marathon runners between 35 and 64 years of age without CV risk factors were eligible. All the participants underwent both 24-hr ambulatory BP monitoring and ESE. EIH was defined as a maximal exercise systolic BP≥210 mmHg. The EIH group (n=19) had shorter training history and higher exercise intensity compared to the non-EIH group (n=23). The average systolic BP was higher in the EIH group than in the non-EIH group. Left cardiac chamber size and left ventricular mass (LVM) were also higher in the EIH group compared to the non-EIH group. Maximal BP during ESE was positively correlated with both parameters. Exaggerated BP response during exercise needs to be monitored for pre-emptive measurements before it results in progressive cardiovascular maladaptation.

First-In-Man Trial of β3-Adrenoceptor Agonist Treatment in Chronic Heart Failure: Impact on Diastolic Function

ABSTRACT

Diastolic dysfunction (DD) in heart failure is associated with increased myocardial cytosolic calcium and calcium-efflux through the sodium-calcium exchanger depends on the sodium gradient. Beta-3-adrenoceptor (β3-AR) agonists lower cytosolic sodium and have reversed organ congestion. Accordingly, β3-AR agonists might improve diastolic function, which we aimed to assess. In a first-in-man, randomized, double-blinded trial, we assigned 70 patients with HF with reduced ejection fraction, New York Heart Association II-III, and left ventricular ejection fraction <40% to receive the β3-AR agonist mirabegron (300 mg/day) or placebo for 6 months, in addition to recommended heart failure therapy. We performed echocardiography and cardiac computed tomography and measured N-terminal probrain natriuretic peptide at baseline and follow-up. DD was graded per multiple renowned algorithms. Baseline and follow-up data were available in 57 patients (59 ± 11 years, 88% male, 49% ischemic heart disease). No clinically significant changes in diastolic measurements were found within or between the groups by echocardiography (E/e' placebo: 13 ± 7 to 13 ± 5, P = 0.21 vs. mirabegron: 12 ± 6 to 13 ± 8, P = 0.74, between-group follow-up difference 0.2 [95% CI, -3 to 4], P = 0.89) or cardiac computed tomography (left atrial volume index: between-group follow-up difference 9 mL/m 2 [95% CI, -3 to 19], P = 0.15). DD gradings did not change within or between the groups following 2 algorithms ( P = 0.72, P = 0.75). N-terminal probrain natriuretic peptide remained unchanged in both the groups ( P = 0.74, P = 0.64). In patients with HF with reduced ejection fraction, no changes were identified in diastolic measurements, gradings or biomarker after β3-AR stimulation compared with placebo. The findings add to the previous literature questioning the role of impaired Na + -Ca 2+ -mediated calcium export as a major culprit in DD. NCT01876433.

Possible Mechanisms for Adverse Cardiac Events Caused by Exercise-Induced Hypertension in Long-Distance Middle-Aged Runners: A Review

Sudden cardiac death (SCD) is rare among athletes. However, hypertrophic cardiomyopathy is the leading cause of SCD among those <35 years of age. Meanwhile, coronary artery disease (CAD) is the primary SCD cause among those ≥35 years of age. CAD-induced plaque ruptures are believed to be a significant cause of cardiovascular diseases in middle-aged individuals who participate in extreme long-distance running activities such as marathons. A total of 1970 articles related to EIH were identified using search terms. Out of these, 1946 studies were excluded for reasons such as arterial hypertension, exercise-induced pulmonary hypertension, the absence of exercise stress testing (EST), and a lack of relevance to EIH. The study analyzed 24 studies related to both long-distance runners with exercise-induced hypertension (EIH) and the general public. Among these, 11 studies were quasi-experimentally designed studies used in randomized controlled trials (RCTs) on long-distance runners with EIH. Additionally, 12 studies utilized cohort designs, and one study with a quasi-experimental design was conducted among the general population. Recent studies suggest that an imbalance between oxygen demand and supply due to ventricular hypertrophy may be the actual cause of cardiovascular disease, regardless of CAD. Exercising excessively over an extended period can reduce endothelial function and increase arterial stiffness, which in turn increases afterload and leads to an excessive increase in blood pressure during exercise. Exercise-induced hypertension (EIH), which increases the morbidity rate of resting hypertension and is a risk factor for cardio-cerebro-vascular diseases, is more prevalent in middle-aged long-distance runners than in runners from other age groups, and it increases the prevalence of critical arrhythmias, such as atrial fibrillation or ventricular arrhythmias. EIH is associated with angiotensin II activity, and angiotensin II receptor blockers show promising effects in middle-aged runners. Further, guidelines for preventing excessive participation in races and restricting exercise intensity and frequency would be useful. This review identifies EIH as a potential risk factor for cardiovascular diseases and describes how EIH induces SCD.

Effect of bariatric surgery on blood pressure response to exercise in a severely obese population

BACKGROUND

Exaggerated blood pressure response to exercise is a cardiovascular risk factor associated to higher morbidity and mortality. Severely obese patients have an increased risk of exercise-induced hypertension (EIH). We aimed to assess the blood pressure response to exercise in patients with severe obesity who underwent bariatric surgery as well as the main determinants of this response.

METHODS

We used data from the ACTIVE clinical trial, in which 60 severely obese patients who underwent bariatric surgery were enrolled. Anthropometric measurements, abdominal and mid-thigh computed tomography scans and maximal exercise testing were performed before bariatric surgery, as well as 3 and 6 months post-surgery. EIH was defined as a maximal SBP ≥210 mmHg for men and ≥190 mmHg for women.

RESULTS

At baseline, 62% of patients had EIH. At 6 months, we observed an EIH resolution rate of 39%. The main determinant of EIH resolution was sex. Actually, patients with EIH resolution were mostly women without resting hypertension and a lower amount of visceral adipose tissue.

CONCLUSION

These results suggest that bariatric surgery is efficient to resolve EIH, particularly in women with initially a better anthropometric profile.

Hypertension and heart failure with preserved ejection fraction: position paper by the European Society of Hypertension

Hypertension constitutes a major risk factor for heart failure with preserved ejection fraction (HFpEF). HFpEF is a prevalent clinical syndrome with increased cardiovascular morbidity and mortality. Specific guideline-directed medical therapy (GDMT) for HFpEF is not established due to lack of positive outcome data from randomized controlled trials (RCTs) and limitations of available studies. Although available evidence is limited, control of blood pressure (BP) is widely regarded as central to the prevention and clinical care in HFpEF. Thus, in current guidelines including the 2018 European Society of Cardiology (ESC) and European Society of Hypertension (ESH) Guidelines, blockade of the renin-angiotensin system (RAS) with either angiotensin-converting enzyme inhibitors or angiotensin receptor blockers provides the backbone of BP-lowering therapy in hypertensive patients. Although superiority of RAS blockers has not been clearly shown in dedicated RCTs designed for HFpEF, we propose that this core drug treatment strategy is also applicable for hypertensive patients with HFpEF with the addition of some modifications. The latter apply to the use of spironolactone apart from the treatment of resistant hypertension and the use of the angiotensin receptor neprilysin inhibitor. In addition, novel agents such as sodium-glucose co-transporter-2 inhibitors, currently already indicated for high-risk patients with diabetes to reduce heart failure hospitalizations, and finerenone represent promising therapies and results from ongoing RCTs are eagerly awaited. The development of an effective and practical classification of HFpEF phenotypes and GDMT through dedicated high-quality RCTs are major unmet needs in hypertension research and calls for action.

Beta-blockers and inhibitors of the renin-angiotensin aldosterone system for chronic heart failure with preserved ejection fraction

BACKGROUND

Beta-blockers and inhibitors of the renin-angiotensin-aldosterone system improve survival and reduce morbidity in people with heart failure with reduced left ventricular ejection fraction (LVEF); a review of the evidence is required to determine whether these treatments are beneficial for people with heart failure with preserved ejection fraction (HFpEF).

OBJECTIVES

To assess the effects of beta-blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, angiotensin receptor neprilysin inhibitors, and mineralocorticoid receptor antagonists in people with HFpEF.

SEARCH METHODS

We updated searches of CENTRAL, MEDLINE, Embase, and one clinical trial register on 14 May 2020 to identify eligible studies, with no language or date restrictions. We checked references from trial reports and review articles for additional studies.  SELECTION CRITERIA: We included randomised controlled trials with a parallel group design, enrolling adults with HFpEF, defined by LVEF greater than 40%.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included 41 randomised controlled trials (231 reports), totalling 23,492 participants across all comparisons. The risk of bias was frequently unclear and only five studies had a low risk of bias in all domains. Beta-blockers (BBs) We included 10 studies (3087 participants) investigating BBs. Five studies used a placebo comparator and in five the comparator was usual care. The mean age of participants ranged from 30 years to 81 years. A possible reduction in cardiovascular mortality was observed (risk ratio (RR) 0.78, 95% confidence interval (CI) 0.62 to 0.99; number needed to treat for an additional benefit (NNTB) 25; 1046 participants; three studies), however, the certainty of evidence was low. There may be little to no effect on all-cause mortality (RR 0.82, 95% CI 0.67 to 1.00; 1105 participants; four studies; low-certainty evidence). The effects on heart failure hospitalisation, hyperkalaemia, and quality of life remain uncertain. Mineralocorticoid receptor antagonists (MRAs) We included 13 studies (4459 participants) investigating MRA. Eight studies used a placebo comparator and in five the comparator was usual care. The mean age of participants ranged from 54.5 to 80 years. Pooled analysis indicated that MRA treatment probably reduces heart failure hospitalisation (RR 0.82, 95% CI 0.69 to 0.98; NNTB = 41; 3714 participants; three studies; moderate-certainty evidence). However, MRA treatment probably has little or no effect on all-cause mortality (RR 0.91, 95% CI 0.78 to 1.06; 4207 participants; five studies; moderate-certainty evidence) and cardiovascular mortality (RR 0.90, 95% CI 0.74 to 1.11; 4070 participants; three studies; moderate-certainty evidence). MRA treatment may have little or no effect on quality of life measures (mean difference (MD) 0.84, 95% CI -2.30 to 3.98; 511 participants; three studies; low-certainty evidence). MRA treatment was associated with a higher risk of hyperkalaemia (RR 2.11, 95% CI 1.77 to 2.51; number needed to treat for an additional harmful outcome (NNTH) = 11; 4291 participants; six studies; high-certainty evidence). Angiotensin-converting enzyme inhibitors (ACEIs) We included eight studies (2061 participants) investigating ACEIs. Three studies used a placebo comparator and in five the comparator was usual care. The mean age of participants ranged from 70 to 82 years. Pooled analyses with moderate-certainty evidence suggest that ACEI treatment likely has little or no effect on cardiovascular mortality (RR 0.93, 95% CI 0.61 to 1.42; 945 participants; two studies), all-cause mortality (RR 1.04, 95% CI 0.75 to 1.45; 1187 participants; five studies) and heart failure hospitalisation (RR 0.86, 95% CI 0.64 to 1.15; 1019 participants; three studies), and may result in little or no effect on the quality of life (MD -0.09, 95% CI -3.66 to 3.48; 154 participants; two studies; low-certainty evidence). The effects on hyperkalaemia remain uncertain. Angiotensin receptor blockers (ARBs) Eight studies (8755 participants) investigating ARBs were included. Five studies used a placebo comparator and in three the comparator was usual care. The mean age of participants ranged from 61 to 75 years. Pooled analyses with high certainty of evidence suggest that ARB treatment has little or no effect on cardiovascular mortality (RR 1.02, 95% 0.90 to 1.14; 7254 participants; three studies), all-cause mortality (RR 1.01, 95% CI 0.92 to 1.11; 7964 participants; four studies), heart failure hospitalisation (RR 0.92, 95% CI 0.83 to 1.02; 7254 participants; three studies), and quality of life (MD 0.41, 95% CI -0.86 to 1.67; 3117 participants; three studies). ARB was associated with a higher risk of hyperkalaemia (RR 1.88, 95% CI 1.07 to 3.33; 7148 participants; two studies; high-certainty evidence). Angiotensin receptor neprilysin inhibitors (ARNIs) Three studies (7702 participants) investigating ARNIs were included. Two studies used ARBs as the comparator and one used standardised medical therapy, based on participants' established treatments at enrolment. The mean age of participants ranged from 71 to 73 years. Results suggest that ARNIs may have little or no effect on cardiovascular mortality (RR 0.96, 95% CI 0.79 to 1.15; 4796 participants; one study; moderate-certainty evidence), all-cause mortality (RR 0.97, 95% CI 0.84 to 1.11; 7663 participants; three studies; high-certainty evidence), or quality of life (high-certainty evidence). However, ARNI treatment may result in a slight reduction in heart failure hospitalisation, compared to usual care (RR 0.89, 95% CI 0.80 to 1.00; 7362 participants; two studies; moderate-certainty evidence). ARNI treatment was associated with a reduced risk of hyperkalaemia compared with valsartan (RR 0.88, 95% CI 0.77 to 1.01; 5054 participants; two studies; moderate-certainty evidence).

AUTHORS' CONCLUSIONS

There is evidence that MRA and ARNI treatment in HFpEF probably reduces heart failure hospitalisation but probably has little or no effect on cardiovascular mortality and quality of life. BB treatment may reduce the risk of cardiovascular mortality, however, further trials are needed. The current evidence for BBs, ACEIs, and ARBs is limited and does not support their use in HFpEF in the absence of an alternative indication. Although MRAs and ARNIs are probably effective at reducing the risk of heart failure hospitalisation, the treatment effect sizes are modest. There is a need for improved approaches to patient stratification to identify the subgroup of patients who are most likely to benefit from MRAs and ARNIs, as well as for an improved understanding of disease biology, and for new therapeutic approaches.

Body composition influences blood pressure during submaximal graded test in women

This study aimed to determine whether body composition affected cardiovascular responses of normal, overweight and obese women by comparing heart rate (HR) and blood pressure (BP) during a graded submaximal treadmill exercise. Thirty five healthy non-smoking, premenopausal women (age 30.8 ± 9.5 yr; height 1.66 ± 0.05 m; weight 73.8 ± 18.9 kg; body fat 36.2 ± 9.5%; maximum oxygen uptake 33.5 ± 8.1 mL·min·kg^-1) volunteered for this study, and were classified into three groups based on BMI: normal weight (NOR; ≤24.9 kg·m²), overweight (OVW; 25-29.9 kg·m²) and obese (OBE; ≥30 kg·m²). Participants performed a submaximal graded test at 30%, 40%, 50% and 60% of maximal oxygen uptake, during which HR, systolic BP (SBP), diastolic BP (DBP) and mean arterial pressure (MAP) were measured. At rest, participants of OBE group had higher BP than NOR and OVW. During the submaximal graded test, HR, SBP and MAP increased as a function of intensity. There were no group differences in HR, but greater SBP, DBP and MAP in OBE compared to NOR and OBW at all intensities except 60%. Overall, our study further contributes to underscore the importance of stress testing specifically to evaluate the increased risks apparently healthy obese women are placed at to developing diseases from the chronic exposure to raised BP, despite normal resting BP and HR responses during exercise.

Exercise-induced hypertension is associated with angiotensin II activity and total nitric oxide

Angiotensin II mediates exercise-induced hypertension (EIH), which adversely impacts future cardiovascular health. There is paucity of data on the association between EIH and angiotensin II in well-trained middle-aged marathoners. Therefore, we investigated the renin-angiotensin-aldosterone-system and total nitric oxide activity in middle-aged marathoners with EIH.Seventy middle-aged marathoners were divided into 3 groups: normal blood pressure ([NBPG] [n = 21]), EIH group ([EIHG] [n = 35]), and complex hypertension group ([CHG] [n = 14]). We defined NBPG as resting systolic BP/diastolic BP (SBP/DBP) of ≤140/90 mm Hg and maximal exercise SBP of ≤210 mm Hg, EIHG as resting SBP/DBP ≤140/90 mm Hg and maximal exercise SBP of ≥210 mm Hg, and CHG as resting SBP/DBP ≥140/90 mm Hg and maximal exercise SBP of ≥210 mm Hg. Renin-angiotensin-aldosterone-system and NO levels were measured before and 30 minutes after the graded exercise test.Renin level was elevated while angiotensin level was reduced after 30 minutes of graded exercise test. There was no change in angiotensin I and angiotensin converting enzyme levels. Comparing the groups, renin level was only elevated in the CHG during recovery, while aldosterone level was higher than the baseline level in the recovery phase in all groups. Angiotensin I level remained unchanged in all groups. Angiotensin II level reduced significantly in the NBPG group but remained at the baseline in the EIHG and CHG groups. NO level was unchanged in the NBPG group but reduced in the EIHG and CHG groups after exercise. At 3 minutes of recovery, SBP was the highest in the NBPG group, followed by the EIHG and CHG groups (P < .05).In conclusion, angiotensin II activity and reduced NO level are associated with EIH in middle-aged long-distance runners. Angiotensin II inhibitors may; therefore, be the more appropriate antihypertensive medication for runners with EIH.

Exploring the determinants of the cardiac changes after ultra-long duration exercise: The echocardiographic Spartathlon study

Aim

The investigation of the pathophysiological determinants of cardiac changes following ultra-long duration exercise.

Methods

Twenty-seven runners who finished a 246 km running race were examined both before and after the finish of the race. Examinations included echocardiography and measurement of body weight and blood biochemical parameters.

Results

Exercise increased left ventricular end-diastolic interventricular septum thickness (LVIVSd) ( p < 0.001) and posterior wall thickness (LVPWTd) ( p = 0.001) and right ventricular end-diastolic area ( p = 0.005), while reduced tricuspid annular plane systolic excursion (TAPSE) ( p = 0.004). A minor decrease in the peak absolute values of both left ventricular (from −20.9 ± 2.3% to −18.8 ± 2.0%, p = 0.009) and right ventricular (from −22.9 ± 3.6% to −21.2 ± 3.0%, p = 0.040) global longitudinal strains occurred. There was decrease in body weight ( p < 0.001) and increase in both circulating high-sensitivity troponin I ( p = 0.028) and amino-terminal pro-B type natriuretic peptide (NT-proBNP) ( p = 0.018). The change in the sum of LVIVSd and LVPWTd correlated negatively with percentage change of body weight ( r = −0.416, p = 0.049). The only independent determinant of post-exercise NT-proBNP was pulmonary artery systolic pressure ( r = 0.797, p = 0.002). Post-exercise NT-proBNP correlated positively with percentage changes of basal (RVbas) ( r = 0.582, p = 0.037) and mid-cavity (RVmid) ( r = 0.618, p = 0.043) right ventricular diameters and negatively with percentage change of TAPSE ( r = −0.720, p = 0.008). Similar correlations with RVbas, RVmid and TAPSE were found for pulmonary artery systolic pressure. Post-exercise high-sensitivity troponin I correlated negatively with percentage change of body weight ( r = −0.601, p = 0.039), but was not associated with any cardiac parameter.

Conclusion

The main cardiac effects of ultra-long duration exercise were the decrease in left ventricular end-diastolic dimensions and increase in left ventricular wall thickness, as well as minimal dilatation and alteration in systolic function of right ventricle, possibly due to the altered exercise-related right ventricular afterload.

Troponin-I levels as a potential prognostic biomarker of sacubitril/valsartan treatment response in heart failure with reduced ejection fraction: Who will benefit most?

BACKGROUND

Despite robust data on the benefits of sacubitril/valsartan (LCZ696) in patients with chronic heart failure with reduced ejection fraction (HFrEF), there is no evidence yet on prespecified predictive markers of its efficacy. Hypothesis The objective of this study was to identify potential prognostic factors of LCZ696 treatment response.

METHODS

We included 48 symptomatic patients with chronic HFrEF (left ventricular ejection fraction ≤35%) and New York Heart Association (NYHA) class II/III: Group A (N = 23) received LCZ696 (105 ± 30 mg twice daily), whereas it was not prescribed in group B (N = 25) according to physician's judgment. Analysis of biochemical parameters, cardiopulmonary exercise testing, and echocardiographic evaluation was performed at baseline and 6 months later.

RESULTS

The baseline serum troponin-I levels (TnI) and peak oxygen uptake (VO₂ max) were positively associated with the increase in VO₂ max (ΔVO₂ max = +14.11%, P < 0.05 vs group B) after sacubitril/valsartan treatment (r = 0.68, P = 0.001 and r = 0.57, P = 0.004, respectively). Positive correlations were reported between ΔVO₂ max and the improvements in the ratio of early diastolic filling to myocardial tissue velocity (ΔE/E') and the tricuspid annular peak systolic velocity (ΔSa) in group A (r = 0.58, P = 0.004 and r = 0.60, P = 0.002, respectively). In multiple regression analysis, ΔVO₂ max was correlated significantly with TnI (beta = 0.35, P = 0.048), ΔE/E' (beta = 0.36, P = 0.031) and ΔSa (beta = 0.37, P = 0.035).

CONCLUSIONS

TnI levels may be an independent predictive marker of sacubitril/valsartan efficacy in HFrEF.

Left atrial remodelling may predict exercise capacity in obstructive sleep apnoea patients

BACKGROUND

Left atrial volume (LAV) and LA deformation has been proposed as a good marker of exercise performance in patients with diastolic dysfunction (DD). As DD is more prevalent in obstructive sleep apnoea (OSA) we aimed to evaluate the influence of LAV and LA deformation parameters on exercise performance in varying severity of OSA.

MATERIALS AND METHODS

OSA was diagnosed after polysomnography. Fifty-five OSA patients were enrolled in the study. OSA patients were divided into two groups with apnoea-hypopna-index (AHI) > 30 and <30. LAV was calculated. LA strain and LA strain rates were assessed with speckle tracking echocardiography (STE). Exercise capacity was evaluated by treadmill exercise test.

RESULTS

MET values were lower in group II compared to group I (p < .05). Echocardiographic findings: Comparison within groups: In both groups E/E', LA stain, LA strain rate S and LA strain rate E were higher after exercise than before (p < .05). In group I LA strain rate A was higher after exercise than before (p < .05). Comparison between groups: LA strain, LA strain rate S, LA strain rate E and LA strain rate A were lower and E/E' and LAVI were higher in group II compared to group I before and after exercise (p < .05). Correlation with METs: AHI, LVEDV, E/E' and LAVI were negatively and LA strain was positively correlated with METs (p < .05).

CONCLUSIONS

Left ventricular diastolic dysfunction is more prevalent in severe OSA and is associated with impaired exercise performance. Additionally, LA remodelling may predict exercise capacity in this subgroup of patients.

Beta-blockers and inhibitors of the renin-angiotensin aldosterone system for chronic heart failure with preserved ejection fraction

BACKGROUND

Beta-blockers and inhibitors of the renin-angiotensin aldosterone system improve survival and reduce morbidity in people with heart failure with reduced left ventricular ejection fraction. There is uncertainty whether these treatments are beneficial for people with heart failure with preserved ejection fraction and a comprehensive review of the evidence is required.

OBJECTIVES

To assess the effects of beta-blockers, angiotensin converting enzyme inhibitors, angiotensin receptor blockers, angiotensin receptor neprilysin inhibitors, and mineralocorticoid receptor antagonists in people with heart failure with preserved ejection fraction.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase and two clinical trial registries on 25 July 2017 to identify eligible studies. Reference lists from primary studies and review articles were checked for additional studies. There were no language or date restrictions.

SELECTION CRITERIA

We included randomised controlled trials with a parallel group design enrolling adult participants with heart failure with preserved ejection fraction, defined by a left ventricular ejection fraction of greater than 40 percent.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies for inclusion and extracted data. The outcomes assessed included cardiovascular mortality, heart failure hospitalisation, hyperkalaemia, all-cause mortality and quality of life. Risk ratios (RR) and, where possible, hazard ratios (HR) were calculated for dichotomous outcomes. For continuous data, mean difference (MD) or standardised mean difference (SMD) were calculated. We contacted trialists where neccessary to obtain missing data.

MAIN RESULTS

37 randomised controlled trials (207 reports) were included across all comparisons with a total of 18,311 participants.Ten studies (3087 participants) investigating beta-blockers (BB) were included. A pooled analysis indicated a reduction in cardiovascular mortality (15% of participants in the intervention arm versus 19% in the control arm; RR 0.78; 95% confidence interval (CI) 0.62 to 0.99; number needed to treat to benefit (NNTB) 25; 1046 participants; 3 studies). However, the quality of evidence was low and no effect on cardiovascular mortality was observed when the analysis was limited to studies with a low risk of bias (RR 0.81; 95% CI 0.50 to 1.29; 643 participants; 1 study). There was no effect on all-cause mortality, heart failure hospitalisation or quality of life measures, however there is uncertainty about these effects given the limited evidence available.12 studies (4408 participants) investigating mineralocorticoid receptor antagonists (MRA) were included with the quality of evidence assessed as moderate. MRA treatment reduced heart failure hospitalisation (11% of participants in the intervention arm versus 14% in the control arm; RR 0.82; 95% CI 0.69 to 0.98; NNTB 41; 3714 participants; 3 studies; moderate-quality evidence) however, little or no effect on all-cause and cardiovascular mortality and quality of life measures was observed. MRA treatment was associated with a greater risk of hyperkalaemia (16% of participants in the intervention group versus 8% in the control group; RR 2.11; 95% CI 1.77 to 2.51; 4291 participants; 6 studies; high-quality evidence).Eight studies (2061 participants) investigating angiotensin converting enzyme inhibitors (ACEI) were included with the overall quality of evidence assessed as moderate. The evidence suggested that ACEI treatment likely has little or no effect on cardiovascular mortality, all-cause mortality, heart failure hospitalisation, or quality of life. Data for the effect of ACEI on hyperkalaemia were only available from one of the included studies.Eight studies (8755 participants) investigating angiotensin receptor blockers (ARB) were included with the overall quality of evidence assessed as high. The evidence suggested that treatment with ARB has little or no effect on cardiovascular mortality, all-cause mortality, heart failure hospitalisation, or quality of life. ARB was associated with an increased risk of hyperkalaemia (0.9% of participants in the intervention group versus 0.5% in the control group; RR 1.88; 95% CI 1.07 to 3.33; 7148 participants; 2 studies; high-quality evidence).We identified a single ongoing placebo-controlled study investigating the effect of angiotensin receptor neprilysin inhibitors (ARNI) in people with heart failure with preserved ejection fraction.

AUTHORS' CONCLUSIONS

There is evidence that MRA treatment reduces heart failure hospitalisation in heart failure with preserverd ejection fraction, however the effects on mortality related outcomes and quality of life remain unclear. The available evidence for beta-blockers, ACEI, ARB and ARNI is limited and it remains uncertain whether these treatments have a role in the treatment of HFpEF in the absence of an alternative indication for their use. This comprehensive review highlights a persistent gap in the evidence that is currently being addressed through several large ongoing clinical trials.

Treatment of Heart Failure with Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) is a growing epidemiologic problem affecting more than half of the patients with heart failure (HF). HFpEF has a significant morbidity and mortality and so far no treatment has been clearly demonstrated to improve the outcomes in HFpEF, in contrast to the efficacy of treatment in heart failure with reduced ejection fraction (HFrEF).The failure of proven beneficial drugs in HFrEF to influence the outcome of patients with HFpEF could be related to the heterogeneity of the disease, its various phenotypes and multifactorial pathophysiology, incompletely elucidated yet. The diagnosis of HFpEF could be demanding or even inaccurate. Moreover, the therapeutic strategies were influenced by different cut-offs used to define preserved ejection fraction (EF). From this perspective, the current guidelines have classified HFpEF by an EF ≥ 50%, together with a distinct entity, heart failure with mid-range ejection fraction (HFmrEF), defined by an EF ranging from 41-49%.New therapies have been developed to interfere with the mediator pathways of HFpEF at the cellular and molecular level, including mineralocorticoid receptor antagonists, soluble guanylate cyclase stimulators, or angiotensin receptor-neprilysin inhibitors. A number of antidiabetic drugs, such as sodium/glucose cotransporter 2 inhibitors and dipeptidyl peptidase-4 inhibitors are promising options, being under research in large clinical trials. Until the results of ongoing trials shed light on these therapies, guidelines recommend empirical treatment for established HFpEF, and emphasize the crucial role of addressing cardiovascular comorbidities leading to HFpEF, in particular arterial hypertension.

Current Perspectives on Systemic Hypertension in Heart Failure with Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) is a prevalent but incompletely understood syndrome. Traditional models of HFpEF pathophysiology revolve around systemic HTN and other causes of increased left ventricular afterload leading to left ventricular hypertrophy (LVH) and diastolic dysfunction. However, emerging models attribute the development of HFpEF to systemic proinflammatory changes secondary to common comorbidities which include HTN. Alterations in passive ventricular stiffness, ventricular-arterial coupling, peripheral microvascular function, systolic reserve, and chronotropic response occur. As a result, HFpEF is heterogeneous in nature, making it difficult to prescribe uniform therapies to all patients. Nonetheless, treating systemic HTN remains a cornerstone of HFpEF management. Antihypertensive therapies have been linked to LVH regression and improvement in diastolic dysfunction. However, to date, no therapies have definitive mortality benefit in HFpEF. Non-pharmacologic management for HTN, including dietary modification, exercise, and treating sleep disordered breathing, may provide some morbidity benefit in the HFpEF population. Future research is need to identify effective treatments, perhaps in more specific subgroups, and focus may need to shift from reducing mortality to improving exercise capacity and symptoms. Tailoring antihypertensive therapies to specific phenotypes of HFpEF may be an important component of this strategy.

Hypertensive response to exercise: mechanisms and clinical implication

A hypertensive response to exercise (HRE) is frequently observed in individuals without hypertension or other cardiovascular disease. However, mechanisms and clinical implication of HRE is not fully elucidated. Endothelial dysfunction and increased stiffness of large artery contribute to development of HRE. From neurohormonal aspects, excess stimulation of sympathetic nervous system and augmented rise of angiotensin II seems to be important mechanism in HRE. Increasing evidences indicates that a HRE is associated with functional and structural abnormalities of left ventricle, especially when accompanied by increased central blood pressure. A HRE harbors prognostic significance in future development of hypertension and increased cardiovascular events, particularly if a HRE is documented in moderate intensity of exercise. As supported by previous studies, a HRE is not a benign phenomenon, however, currently, whether to treat a HRE is controversial with uncertain treatment strategy. Considering underlying mechanisms, angiotensin receptor blockers and beta blockers can be suggested in individuals with HRE, however, evidences for efficacy and outcomes of treatment of HRE in individuals without hypertension is scarce and therefore warrants further studies.

Pharmacotherapy of Congestive Heart Failure in Elderly Patients

With longer life expectancy, as well as better survival rates after myocardial infarction, the population of elderly patients with congestive heart failure steadily increases. Large, randomized, placebo-controlled studies have shown significant beneficial effects for several classes of drugs (angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, β-blockers, aldosterone antagonists) in patients with congestive heart failure. In most of these studies, however, elderly patients were either excluded or represented only a minority of the study population. Therefore, the treatment benefit for the large population of patients aged 65 and older is still not very well documented. In this paper, we critically review the current literature with regard to outcome of heart failure therapy in this particular subpopulation.

Targeting heart failure with preserved ejection fraction: current status and future prospects

Heart failure with preserved ejection fraction (HFpEF) portrays a significant burden in terms of prevalence, morbidity, mortality, and health care costs. There is a lack of consensus on the basic pathophysiology, definition, and therapeutic targets for therapy for this syndrome. To date, there are no approved therapies available for reducing mortality or hospitalization for these patients. Several clinical trials have recently started to try and bridge this major gap. There is an urgent need to focus on drug and device development for HFpEF as well as to understand HFpEF pathophysiology.

The combined exercise stress echocardiography and cardiopulmonary exercise test for identification of masked heart failure with preserved ejection fraction in patients with hypertension

BACKGROUND

Heart failure with preserved ejection fraction (HFpEF) is commonly associated with hypertension (HTN). However, resting echocardiography (ECHO) can underestimate the severity of disease. Exercise stress echocardiography (ESE) and the cardiopulmonary exercise testing (CPX) appeared to be useful tests in dynamic assessment of HFpEF. The value of combined exercise stress echocardiography cardiopulmonary testing (ESE-CPX) in the identification of masked HFpEF is still undetermined.

OBJECTIVE

The purpose of this study was to analyse the value of the combined ESE-CPX in the identification of masked HFpEF in patients with HTN, dyspnoea and normal resting left ventricular (LV) systolic and diastolic function.

METHODOLOGY

We studied 87 patients with HTN, exertional dyspnoea and normal resting LV function. They all underwent ESE-CPX testing (supine bicycle, ramp protocol, 15 W/min). ECHO measurements were performed at rest, and at peak load. Achievement of peak E/e' ratio>15 was a marker for masked HFpEF.

RESULTS

Increase of E/e'>15 occurred in 8/87 patients (9.2%) during ESE-CPX. Those patients had the lower peak VO2 (p = 0.012), the lower VO2 at anaerobic threshold (p = 0.025), the lower workload (p = 0.026), the lower peak partial pressure end tidal carbon dioxide (PetCO2) (p < 0.0001), and the higher VE/VCO2 slope (p < 0.0001) which was an independent multivariate predictor of HFpEF (p = 0.021), with the cut-off value of 32.95 according to the receiver-operator characteristic (ROC) curve (sensitivity (Sn) 100%, specificity (Sp) 90%).

CONCLUSION

The combined ESE-CPX test is feasible and reliable test that can unmask HFpEF and may become an important aid in the early diagnosis of HFpEF, excluding the other causes of exertional dyspnoea.

Cardiopulmonary Exercise Test in Patients with Hypertension: Focused on Hypertensive Response to Exercise

The cardiopulmonary exercise test (CPET) provides integrative exercise responses including the cardiovascular, pulmonary and skeletal muscle systems. It can be used for the identification of myocardial ischemia, evaluation of exercise capacity and tolerance, and the assessment of chronotropic competence or arrhythmias with the addition of ventilatory and gas exchange measurement information. Among them, hypertensive response to exercise (HRE) is known to be related with higher risk of future heart failure and cardiovascular events in patients with hypertension. Proposed underlying mechanisms of HRE can be found in ventricular-vascular uncoupling including decreased aortic distensibility, increased left ventricular mass, endothelial dysfunction, and diastolic dysfunction. The CPET might be useful in the identification of masked hypertension and the assessment of antihypertensive treatment efficacy in patients with hypertension.

Comparison of different interdialytic intervals among hemodialysis patients on their echocardiogram-based cardiovascular parameters

BACKGROUND

Although cardiovascular events in hemodialysis (HD) patients are the most frequent on the day after a long (2 days) interdialytic interval (IDT), it has been uncertain whether accumulation or elimination of large extracellular fluid volume, electrolyte, and/or uremic substances is the culprit for this. We sought to test our hypothesis that the long IDT alters echocardiographic parameters at rest and during exercise in stable maintenance HD patients compared with other IDTs.

METHODS

We performed a cross-sectional comparison using 1-way repeated analysis of variance or Friedman test of echocardiograms at 3 different IDTs, just after HD, after short IDT (1 day), and after long IDT, among 80 stable Japanese outpatients (age 61 ± 9 years, 60 males) on thrice weekly maintenance. End-systolic elastance (Ees), arterial elastance (Ea), and pressure-volume area (PVA) were estimated using a noninvasive single-beat technique. Ventricular-arterial coupling was assessed by Ea/Ees ratio. Measurements were repeated after 2-minute handgrip stress to evaluate cardiac reserve.

RESULTS

Resting left ventricular end-diastolic volume index and stroke volume index were significantly larger after a 1-day IDT compared with just after HD and even more after a 2-day IDT. Although Ees, Ea, and Ea/Ees ratio at rest remained similar between short and long intervals, stroke work (SW) and PVA were higher after the long interval. During handgrip stress, a significant increase in Ea without corresponding rise in Ees was observed only after long IDT, resulting in decreased stroke volume index, SW, and SW/PVA efficiency.

CONCLUSIONS

In a selective Japanese outpatient population on maintenance HD, there were no differences in resting cardiovascular function measured by echocardiography at 3 different IDTs. However, exercise-induced afterload mismatch assessed by the changes in Ea, SV, SW, and SW/PVA efficiency was most pronounced in individuals after the long IDT compared with other IDTs. Our findings report potential pathophysiologic echocardiographic parameters that attempt to explain why cardiovascular events are highest on the day after the long IDT compared to other IDTs in dialysis patients.

Biomarkers and echocardiographic predictors of myocardial dysfunction in patients with hypertension

The study aimed to identify early echocardiographic and circulating biomarkers of heart failure (HF) in hypertensive patients with normal resting echocardiography. Echocardiography at rest and during exercise, and selected biomarkers were assessed in control group, dyspnea group, and HF group. On exercise dyspnea patients had lower early diastolic (E') and systolic (S') mitral annular velocity (12.8 ± 1.0 vs 14.9 ± 3.0 cm/sec and 9.3 ± 2.0 vs 10.9 ± 2.0 cm/sec, respectively), and higher E/E' ratio compared to control group (6.7 ± 1.0 vs 5.9 ± 1.0) (p < 0.05 for all comparisons). The level of N-terminal propeptide of procollagen type III (PIIINP) was significantly higher in dyspnea group than in controls (p = 0.01). Control and dyspnea patients had lower levels of cardiotrophin-1, cystatin C, syndecan-4, and N terminal-probrain natriuretic peptide than HF patients (all p ≤ 0.01). In multivariate analysis PIIINP (unadjusted odds ratio [OR] = 8.2, 95% confidence interval [Cl] 1.7-40.6; p = 0.001; adjusted OR = 8.7; 95%CI: 1.5-48.3; p = 0.001) and E/E' ratio on exercise (unadjusted OR = 1.8, 95%CI: 0.8-4.0; p = 0.033; adjusted OR = 2.0; 95%CI: 0.8-4.8; p = 0.012) were the only factors significantly associated with the presence of dyspnea. PIIINP is the first early biomarker for the HF development in patients with HA and normal resting echocardiography. Exertional echocardiography may indicate patients with incipient HF with preserved ejection fraction.

Association between invasively measured central aortic pressure and left ventricular diastolic function in patients undergoing coronary angiography

BACKGROUND

Because of the invasive nature of catheterization, limited information is available on hemodynamic interaction between the left ventricle and aorta using invasive aortic pressure monitoring. Our aim was to investigate whether parameters of invasively measured central aortic pressure waveform were related with those of left ventricular (LV) diastolic function.

METHODS

A total of 153 consecutive stable patients (mean age = 64±11 years; 62% men) undergoing invasive coronary angiography (ICA) and transthoracic echocardiography (TTE) were prospectively evaluated. Central aortic pressure waveform was obtained at the ascending aorta using a pigtail catheter before ICA. We calculated pulse pressure (PP), fractional PP (FPP; the ratio of PP to mean pressure), pulsatility index (PI; the ratio of PP to diastolic pressure), augmentation index, wave reflection time, and ejection duration and analyzed their associations with parameters of LV diastolic function in TTE.

RESULTS

Most patients (n = 135/153; 88.2%) had significant stenosis (≥50%) of ≥1 epicardial coronary arteries. In multiple linear regression analyses, e' and E/e' were significantly correlated with PP, FPP, and PI even after adjustment for potential confounders. There were no significant correlations between other parameters of LV diastolic function, including E/A, deceleration time, and left atrial volume index and parameters of central aortic pressure wave.

CONCLUSIONS

Invasively measured central aortic PP, FPP, and PI were independently associated with e' and E/e' in patients undergoing ICA. This result adds to the evidence of a close interaction between LV diastolic function and aortic stiffness in this population.

Managing blood pressure control in Asian patients: safety and efficacy of losartan

Hypertension is common in Asian populations and is a major cause of cardiovascular diseases. The prevalence of hypertension is increasing in many Asian countries. The overall prevalence of hypertension in India and the People’s Republic of China has been estimated to be 20.6% in men and 22.6% in women. However, the rates of detection, treatment, and control of hypertension remain low in Asia. This reflects a low level of literacy and education, as well as a low level of access to medical care. To overcome these obstacles, strategies targeted at education, promotion, and optimization of medical care, are crucial to achieve target blood pressure control. Angiotensin receptor blockers are one of the first-line treatments for essential hypertension because they confer better cardiovascular outcomes. Losartan has been widely evaluated for the management of hypertension. Although some studies suggested that the blood pressure-lowering effect of losartan is perhaps lower than for other angiotensin receptor blockers, losartan has been demonstrated to be beneficial in terms of renal protection in patients with diabetes, heart failure resulting from either systolic or diastolic dysfunction, and diuretic-induced hyperuricemia. However, most of these data were obtained from Caucasian populations. The efficacy and safety of losartan in Asian populations may be different because of genetic and ethnic variations. Therefore, the efficacy and safety of losartan in Asian patients with hypertension warrant further study.

Prevention of remodeling in congestive heart failure due to myocardial infarction by blockade of the renin–angiotensin system

Ventricular remodeling subsequent to myocardial infarction (MI) is a complex process and is considered to be a major determinant of the clinical course of congestive heart failure (CHF). Emerging evidence suggests that activation of the renin-angiotensin system (RAS) plays an important role in post-MI ventricular remodeling; however, it is becoming clear that this is one of several neurohumoral systems that are activated in CHF. Blockade of RAS by angiotensin-converting enzyme inhibitors or angiotensin II type 1 receptor antagonists attenuates the ventricular dysfunction, but the effects of individual drugs in reducing the morbidity and mortality in CHF patients are variable. Furthermore, there is a difference of opinion as to the time of initiation of therapy with RAS blockers after the onset of MI. Since blockade of RAS partially improves cardiac function, it is suggested that a combination therapy involving RAS blockers (angiotensin-converting enzyme inhibitors or angiotensin II type 1 receptor antagonists) and agents that affect other neurohumoral systems may prove useful for improved treatment of CHF. Although activation of RAS has been shown to promote oxidative stress in experimental studies, the use of antioxidant therapy in CHF patients is controversial. Recent experimental studies have shown that ventricular remodeling in CHF is associated with remodeling of subcellular organelles such as sarcolemma, sarcoplasmic reticulum, myofibrils and extracellular matrix in terms of their molecular structure and composition. Since attenuation of remodeling in one and/or more subcellular organelles by different agents may prevent the progression of CHF, it is a challenge to develop specific drugs affecting molecular mechanisms associated with subcellular remodeling for the improved therapy of CHF.

Update on heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFPEF) is the most common form of heart failure (HF) in older adults, and is increasing in prevalence as the population ages. Morbidity and long-term mortality in HFPEF are substantial and can be similar to HF with reduced ejection fraction (HFREF), yet HFPEF therapy remains empirical and treatment guidelines are based primarily on expert consensus. Neurohormonal blockade has revolutionized the management of HFREF, but trials in HFPEF based on this strategy have been disappointing to date. However, many recent studies have increased knowledge about HFPEF. The concept of HFPEF has evolved from a 'cardio-centric' model to a syndrome that may involve multiple cardiovascular and non-cardiovascular mechanisms. Emerging data highlight the importance of non-pharmacological management strategies and assessment of non-cardiovascular comorbidities. Animal models, epidemiological cohorts, and small human studies suggest that oxidative stress and inflammation contribute to HFPEF, potentially leading to development of new therapeutic targets.

Impact of spironolactone on vascular, myocardial, and functional parameters in untreated patients with a hypertensive response to exercise

BACKGROUND

Although a hypertensive response to exercise (HRE) is associated with cardiac risk and masked hypertension (MHT), its mechanisms and appropriate treatment remain unclear. We investigated spironolactone as a treatment for abnormal vascular and myocardial stiffness in HRE.

METHODS

In this randomized, double-blind, placebo-controlled study of 115 patients (54 ± 9 years, 57% men) with an HRE (≥210/105 mm Hg in men; ≥190/105 mm Hg in women) but no prior history of hypertension or myocardial ischemia, MHT prevalence was 40%. Patients were randomized to spironolactone 25mg daily (n = 58) or placebo (n = 57) and underwent evaluation at baseline and 3 months with exercise echocardiography, VO2max, pulse wave velocity (PWV), exercise and central blood pressure (BP), and 24-hour ambulatory BP. Changes in left ventricular mass index (LVMI), Doppler-derived E/em ratio (LV filling pressure), and myocardial strain were assessed.

RESULTS

Baseline 24-hour systolic BP (SBP) was 133 ± 10 mm Hg and peak-exercise SBP was 219 ± 16 mm Hg. Peak systolic strain (0.3 ± 3.6% vs. -0.1 ± 3.2, P = 0.56), E/em (-1.1 ± 2.3 vs. -0.6 ± 1.7, P = 0.30), VO(2max) (0.4 ± 4.9 vs. -0.9 ± 4.1 ml/kg/min, P = 0.15), and adjusted PWV did not significantly change with treatment, despite reduction in exercise SBP, 24-hour SBP, and LVMI. The change in exercise E/em was of borderline significance (-0.3 ± 2.4 vs. 0.8 ± 2.8, P = 0.06) and became significant after adjustment for baseline differences (P = 0.01). Patients with higher LVMI significantly increased VO(2max) (1.1 ± 5.6 vs. -2.4 ± 4.4 ml/kg/min, P < 0.05) and reduced exercise E/e(m) (-0.7 ± 2.7 vs. 1.9 ± 2.8, P < 0.05).

CONCLUSIONS

In HRE patients without previous hypertension, short-term spironolactone reduced exercise BP, 24-hour ambulatory BP, LVMI, and E/e(m) but did not significantly alter exercise capacity or myocardial strain.

Exercise testing in hypertensive patients for assessing the cardiovascular protective potential of antihypertensive drugs

Exercise testing is an established noninvasive tool in cardiology used to diagnose and guide treatment in individuals with suspected or confirmed coronary artery disease. Owing to the wealth of information it provides, exercise testing is also being utilized to evaluate prehypertensive stages, characterize hypertension, assess tolerance to exercise and the efficacy of antihypertensive therapies, and predict target organ damage and cardiovascular risk. The literature on exercise tolerance tests is relatively limited since these studies are difficult to conduct although they represent a valuable test for evaluating the benefits of antihypertensive therapies beyond their blood-pressure-lowering efficacy at rest or during exercise. Such a setting can be immensely useful for the evaluation and for the differentiation of treatments, especially in patients with evident rises in systolic blood pressure and with concomitant diseases, who are at higher risk of stroke. Exercise-induced increase in systolic blood pressure from rest to peak exercise should therefore be used as the primary efficacy variable. There is growing evidence that central pressure is a better predictor for cardiovascular risk than peripheral blood pressure, since this variable takes into account the overall effect of vascular aging and increased arterial stiffness that age and other concomitant diseases may induce. It is also important to include central aortic blood pressure and biomarkers of hypertension and cardiac disease in the overall assessment.

Left ventricular vortex formation is unaffected by diastolic impairment

Normal left ventricular (LV) filling occurs rapidly early in diastole caused by a progressive pressure gradient within the ventricle and with a low left atrial pressure. This normal diastolic function is altered in patients with heart failure. Such impairment of diastolic filling is manifested as an abrupt deceleration of the early filling wave velocity. Although variations within the early filling wave have been observed previously, the underlying hydrodynamic mechanisms are not well understood. Previously, it was proposed that the mitral annulus vortex ring formation time was the total duration of early diastolic filling and provided a measure of the efficiency of diastolic filling. However, we found that the favorable LV pressure difference driving early diastolic filling becomes zero simultaneously with the deceleration of the early filling wave propagation velocity and pinch-off of the LV vortex ring. Thus we calculated the vortex ring formation time using the duration of the early diastolic filling wave from its initiation to the time of the early filling wave propagation velocity deceleration when pinch-off occurs. This formation time does not vary with decreasing intraventricular pressure difference or with degree of diastolic dysfunction. Thus we conclude the vortex ring pinch-off occurs before the completion of early diastole, and its formation time remains invariant to changes of diastolic function.

Blood pressure and plasma renin activity responses to different strategies to inhibit the renin-angiotensin-aldosterone system during exercise

OBJECTIVE

The effect of two different strategies for renin-angiotensin-aldosterone system (RAAS) blockade; direct renin inhibition (DRI) versus angiotensin receptor blockade (ARB) on blood pressure (BP) and plasma renin activity (PRA) was compared during exercise.

METHODS

Hypertensive adults were randomised to aliskiren (300 mg once daily, n=33) or valsartan (320 mg once daily, n=35). BP and PRA were measured during treadmill exercise (Bruce protocol), at baseline, end of treatment (eight weeks), and after treatment withdrawal (48 hours after last dose).

RESULTS

After eight weeks treatment, Aliskiren inhibited PRA (>80%) at rest and during exercise, with inhibition remaining undiminished 48 hours after treatment withdrawal. In contrast, valsartan increased PRA at rest, and more-so during exercise (>400%). Angiotensin receptor blockade, as indicated by PRA increase, was reduced, 48 hours after valsartan treatment withdrawal, suggesting more sustained RAAS blockade with aliskiren. Despite divergent effects on PRA, similar exercise-induced changes in BP were seen. The primary outcome, the rise in systolic BP from rest to peak exercise (baseline to after treatment withdrawal) did not differ between treatments (p=0.25).

CONCLUSION

Measurement of PRA is a more sensitive index of RAAS blockade than the BP response during exercise. Furthermore, after treatment withdrawal, aliskiren provides more sustained RAAS inhibition than valsartan at rest and during exercise.

Differential effects of late-life initiation of low-dose enalapril and losartan on diastolic function in senescent Fischer 344 x Brown Norway male rats

No proven pharmacological therapies to delay or reverse age-related diastolic dysfunction exist. We hypothesized that late-life low-dose (non-blood-pressure-lowering) angiotensin-converting enzyme inhibition vs. angiotensin II receptor blockade would be equally efficacious at mitigating diastolic dysfunction in the senescent Fischer 344 × Brown Norway rat. Enalapril (10 mg/kg/day; n = 9) initiated at 24 months of age and continued for 6 months, increased myocardial relaxation (e'), reduced Doppler-derived indices of filling pressure (E/e'), favorably lowered the ratio of phospholamban-SERCA2 and reduced oxidative stress markers, Rac1 and nitrotyrosine, in aged hearts. Treatment with losartan (15 mg/kg/day; n = 9) similarly mitigated signs of cardiac oxidative stress, but impairments in diastolic function persisted when compared with untreated rats (n = 7). Our findings favor the idea that the lusitropic benefit of low-dose angiotensin-converting enzyme inhibitor initiated late in life may be related to an antioxidant-mediated modulation of SERCA2, resulting in improved relaxation rather than via overt effects on cardiac structure or blood pressure.

Diastolic Heart Failure

Multiple recent epidemiologic studies have highlighted the importance of diastolic heart failure (DHF) as a public health problem. Approximately half of patients presenting with symptomatic heart failure (HF) have DHF and they suffer from morbidity and mortality comparable to those with systolic HF. Our understanding of the pathophysiology of DHF has evolved rapidly over the last decade, and the associated echo-Doppler findings that assist with its diagnosis are greatly refined. Recently, there has been increased recognition of the role of diastolic dysfunction and DHF in the care of critically ill patients, including those admitted to noncardiac units. The purpose of this review is to provide an up-to-date summary of the concepts of the pathophysiology of DHF. In addition, we provide an overview of the diagnostic approaches, prognostic identifiers, and associated comorbidities that make DHF more resistant to manage with a focus of the patients admitted to the intensive care unit. The current approach to managing patients with DHF is also reviewed.

Heart failure in the elderly

The aging of the population is, currently, a major phenomenon, drawing the attention of a number of investigators. The significant increase of life expectancies over the past few decades, in addition to social and economic consequences, has lead to a major change in the morbidity and mortality profile of elders. Heart failure (HF) is a condition in which the heart can not pump enough blood to meet the body's needs. HF is predominantly a disorder of the elderly with rates increasing exponentially. The prevalence of HF approximately doubles with each decade of life. As people live longer, the occurrence of HF rises, as well as other conditions that complicate its treatment. Impaired heart function implies a reduced duration of survival. Fortunately, many factors that can prevent HF and improve outcome are known and can be applied at any stage. This review emphasizes the importance of factors inherent in aging itself, focusing on heart disease, particularly as a disease of aging, can help critically refine management of this acute and chronic disease, as well as foster preventive strategies to reduce the incidence of this common malady.

Heart failure with normal ejection fraction: a growing pandemic

Heart failure is a heterogeneous syndrome. Approximately 30-50% of patients with heart failure have normal or near normal left ventricle function. Several epidemiological studies confirm that the prevalence of heart failure with normal ejection fraction is increasing. Given the current trends, heart failure with normal ejection fraction will become the most common form of heart failure, for which we do not currently have an evidence-based successful treatment. This article summarizes the etiology, current recommended guidelines and management options for this clinical manifestation.

Ventricular-vascular interaction in heart failure

Nearly half of all patients who have heart failure have preserved ejection fraction (HFpEF). Patients who have HFpEF tend to be older, female, and hypertensive, and characteristically display increased ventricular and arterial stiffening. In this article, we discuss the pathophysiology of abnormal ventriculoarterial stiffening and how it affects ventricular function, cardiovascular hemodynamics, reserve capacity, and symptoms. We conclude by exploring how novel treatment strategies targeting abnormal ventricular-arterial interaction might prove useful in the treatment of patients who have HFpEF.

Exercise intolerance

Exercise intolerance is the primary symptom of chronic diastolic heart failure. It is part of the definition of heart failure and is intimately linked to its pathophysiology. Further, exercise intolerance affects the diagnosis and prognosis of heart failure. In addition, understanding the mechanisms of exercise intolerance can lead to developing and testing rational treatments for heart failure. This article focuses on the fundamental principles of exercise physiology and on the assessment, pathophysiology, and potential treatment of exercise intolerance in diastolic heart failure.

Determinants of exercise intolerance in elderly heart failure patients with preserved ejection fraction

OBJECTIVES

The purpose of this study was to determine the mechanisms responsible for reduced aerobic capacity (peak Vo(2)) in patients with heart failure with preserved ejection fraction (HFPEF).

BACKGROUND

HFPEF is the predominant form of heart failure in older persons. Exercise intolerance is the primary symptom among patients with HFPEF and a major determinant of reduced quality of life. In contrast to patients with heart failure and reduced ejection fraction, the mechanism of exercise intolerance in HFPEF is less well understood.

METHODS

Left ventricular volumes (2-dimensional echocardiography), cardiac output, Vo(2), and calculated arterial-venous oxygen content difference (A-Vo(2) Diff) were measured at rest and during incremental, exhaustive upright cycle exercise in 48 HFPEF patients (age 69 ± 6 years) and 25 healthy age-matched controls.

RESULTS

In HFPEF patients compared with healthy controls, Vo(2) was reduced at peak exercise (14.3 ± 0.5 ml·kg·min(-1) vs. 20.4 ± 0.6 ml·kg·min(-1); p < 0.0001) and was associated with a reduced peak cardiac output (6.3 ± 0.2 l·min(-1) vs. 7.6 ± 0.2 l·min(-1); p < 0.0001) and A-Vo(2) Diff (17 ± 0.4 ml·dl(-1) vs. 19 ± 0.4 ml·dl(-1), p < 0.0007). The strongest independent predictor of peak Vo(2) was the change in A-Vo(2) Diff from rest to peak exercise (A-Vo(2) Diff reserve) for both HFPEF patients (partial correlate, 0.58; standardized β coefficient, 0.66; p = 0.0002) and healthy controls (partial correlate, 0.61; standardized β coefficient, 0.41; p = 0.005).

CONCLUSIONS

Both reduced cardiac output and A-Vo(2) Diff contribute significantly to the severe exercise intolerance in elderly HFPEF patients. The finding that A-Vo(2) Diff reserve is an independent predictor of peak Vo(2) suggests that peripheral, noncardiac factors are important contributors to exercise intolerance in these patients.

Stress induced hypertensive response: should it be evaluated more carefully?

Various diagnostic methods have been used to evaluate hypertensive patients under physical and pharmacological stress. Several studies have shown that exercise hypertension has an independent, adverse impact on outcome; however, other prognostic studies have shown that exercise hypertension is a favorable prognostic indicator and associated with good outcome. Exercise hypertension may be encountered as a warning signal of hypertension at rest and future hypertensive left ventricular hypertrophy. The results of diagnostic stress tests support that hypertensive response to exercise is frequently associated with high rate-pressure product in hypertensives. In addition to the observations on high rate-pressure product and enhanced ventricular contractility in patients with hypertension, evaluation of myocardial contractility by Doppler tissue imaging has shown hyperdynamic myocardial function under pharmacological stress. These recent quantitative data in hypertensives suggest that hyperdynamic myocardial function and high rate-pressure product response to stress may be related to exaggerated hypertension, which may have more importance than that it has been already given in clinical practice.

Pharmacologic management of heart failure with preserved ejection fraction

OBJECTIVE

To provide an overview of heart failure with preserved ejection fraction (HFPEF), as well as its pathophysiology, diagnosis, and clinical evidence regarding its pharmacologic management.

DATA SOURCES

Peer-reviewed articles were identified from MEDLINE, International Pharmaceutical Abstracts, and Current Contents (all 1966-August 2010) using the search terms heart failure with preserved ejection fraction, diastolic dysfunction, diastolic heart failure, angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), digoxin, β-blockers, calcium-channel blockers, and vasodilators. Citations from available articles were also reviewed for additional references.

STUDY SELECTION AND DATA EXTRACTION

Fourteen published manuscripts relating to pharmacologic management of HFPEF were identified.

DATA SYNTHESIS

The prevalence of HFPEF has continued to increase. Compared to heart failure with left ventricular systolic dysfunction, HFPEF has been largely understudied. Unlike in the management of heart failure with left ventricular systolic dysfunction, ACE inhibitors, ARBs, β-blockers, and aldosterone antagonists did not demonstrate mortality benefit in HFPEF, with the exception of one small study evaluating the use of propranolol. However, this study enrolled a small number of patients with recent history of myocardial infarction, which limited the generalizability of the results. Most of the current evidence centers on morbidity benefits and symptom reduction. One study showed that treatment with candesartan reduced hospital admissions in this population of patients. Management of HFPEF still focuses on optimally managing underlying diseases (eg, hypertension).

CONCLUSIONS

Much remains to be learned about the appropriate pharmacologic management of patients with HFPEF. Hypertension is in most cases the predominant contributor to its development and progression. For this reason, antihypertensive treatment, including ACE inhibitors, ARBs, β-blockers, and calcium-channel blockers, has been evaluated and is recommended to control the disease in this patient population, although these agents have not demonstrated significant benefit beyond blood pressure control. Further research into the pathophysiology of HFPEF may contribute to identifying the most optimal agent in managing this disease.

The clinical quandary of left and right ventricular diastolic dysfunction and diastolic heart failure

Summary

Diastolic heart failure is a common clinical entity that is indistinguishable from systolic heart failure without direct evaluation of left ventricular function. Diastolic heart failure is a clinical diagnosis in patients with signs and symptoms of heart failure but with preserved left ventricular function and normal ejection fraction, and is often seen in patients with a long-standing history of hypertension or infiltrative cardiac diseases. In contrast, diastolic dysfunction represents a mechanical malfunction of the relaxation of the left ventricular chamber that is primarily diagnosed by two-dimensional transthoracic echocardiography and usually does not present clinically as heart failure. The abnormal relaxation is usually separated in different degrees, based on the severity of reduction in passive compliance and active myocardial relaxation. The question whether diastolic dysfunction ultimately will lead to diastolic heart failure is critically reviewed, based on data from the literature. Treatment recommendations for diastolic heart failure are primarily targeted at risk reduction and symptom relief. Currently, few data only are reported on diastolic dysfunction and its progression to systolic heart failure.

Exercise training in older patients with heart failure and preserved ejection fraction: a randomized, controlled, single-blind trial

BACKGROUND

Heart failure (HF) with preserved left ventricular ejection fraction (HFPEF) is the most common form of HF in the older population. Exercise intolerance is the primary chronic symptom in patients with HFPEF and is a strong determinant of their reduced quality of life (QOL). Exercise training (ET) improves exercise intolerance and QOL in patients with HF with reduced ejection fraction (EF). However, the effect of ET in HFPEF has not been examined in a randomized controlled trial.

METHODS AND RESULTS

This 16-week investigation was a randomized, attention-controlled, single-blind study of medically supervised ET (3 days per week) on exercise intolerance and QOL in 53 elderly patients (mean age, 70±6 years; range, 60 to 82 years; women, 46) with isolated HFPEF (EF ≥50% and no significant coronary, valvular, or pulmonary disease). Attention controls received biweekly follow-up telephone calls. Forty-six patients completed the study (24 ET, 22 controls). Attendance at exercise sessions in the ET group was excellent (88%; range, 64% to 100%). There were no trial-related adverse events. The primary outcome of peak exercise oxygen uptake increased significantly in the ET group compared to the control group (13.8±2.5 to 16.1±2.6 mL/kg per minute [change, 2.3±2.2 mL/kg per minute] versus 12.8±2.6 to 12.5±3.4 mL/kg per minute [change, -0.3±2.1 mL/kg per minute]; P=0.0002). There were significant improvements in peak power output, exercise time, 6-minute walk distance, and ventilatory anaerobic threshold (all P<0.002). There was improvement in the physical QOL score (P=0.03) but not in the total score (P=0.11).

CONCLUSIONS

ET improves peak and submaximal exercise capacity in older patients with HFPEF.