Angiotensin-converting enzyme inhibitors in preventing remodeling and development of heart failure after acute myocardial infarction: results of the German multicenter study of the effects of captopril on cardiopulmonary exercise parameters (ECCE)

Medical Therapies for Heart Failure in Hypoplastic Left Heart Syndrome

Significant surgical and medical advances over the past several decades have resulted in a growing number of infants and children surviving with hypoplastic left heart syndrome (HLHS) and other congenital heart defects associated with a single systemic right ventricle (RV). However, cardiac dysfunction and ultimately heart failure (HF) remain the most common cause of death and indication for transplantation in this population. Moreover, while early recognition and treatment of single ventricle-related complications are essential to improving outcomes, there are no proven therapeutic strategies for single systemic RV HF in the pediatric population. Importantly, prototypical adult HF therapies have been relatively ineffective in mitigating the need for cardiac transplantation in HLHS, likely due to several unique attributes of the failing HLHS myocardium. Here, we discuss the most commonly used medical therapies for the treatment of HF symptoms in HLHS and other single systemic RV patients. Additionally, we provide an overview of potential novel therapies for systemic ventricular failure in the HLHS and related populations based on fundamental science, pre-clinical, clinical, and observational studies in the current literature.

Heart failure in single right ventricle congenital heart disease: physiological and molecular considerations

Because of remarkable surgical and medical advances over the past several decades, there are growing numbers of infants and children living with single ventricle congenital heart disease (SV), where there is only one functional cardiac pumping chamber. Nevertheless, cardiac dysfunction (and ultimately heart failure) is a common complication in the SV population, and pharmacological heart failure therapies have largely been ineffective in mitigating the need for heart transplantation. Given that there are several inherent risk factors for ventricular dysfunction in the setting of SV in addition to probable differences in molecular adaptations to heart failure between children and adults, it is perhaps not surprising that extrapolated adult heart failure medications have had limited benefit in children with SV heart failure. Further investigations into the molecular mechanisms involved in pediatric SV heart failure may assist with risk stratification as well as development of targeted, efficacious therapies specific to this patient population. In this review, we present a brief overview of SV anatomy and physiology, with a focus on patients with a single morphological right ventricle requiring staged surgical palliation. Additionally, we discuss outcomes in the current era, risk factors associated with the progression to heart failure, present state of knowledge regarding molecular alterations in end-stage SV heart failure, and current therapeutic interventions. Potential avenues for improving SV outcomes, including identification of biomarkers of heart failure progression, implications of personalized medicine and stem cell-derived therapies, and applications of novel models of SV disease, are proposed as future directions.

Prognosis of myocardial infarction with left ventricular dysfunction in the coronary revascularization era.Subanalysis of the Japanese Coronary Artery Disease (JCAD) Study

BACKGROUND

Indications of implantable cardioverter-defibrillator (ICD) for patients with an old myocardial infarction (OMI) and left ventricular dysfunction (LVD) were expanded in Western countries after the results of MADIT II. However, the prognosis of OMI patients with LVD and the merits of prophylactic implantation of ICD, based on evidence in Japan, have not yet been clarified. This subanalysis of the Japanese Coronary Artery Disease (JCAD) Study focused on MADIT II-compatible patients to clarify the prognosis of OMI patients with LVD in Japan.

METHODS AND RESULTS

Consecutive 6,868 OMI patients were prospectively followed up for 3 years or until clinical events occurred. 291 patients had left ventricular ejection fraction (LVEF) ≤30%. Clinical events, congestive heart failure, cardiopulmonary arrest on arrival and vascular events were significantly more frequent in patients with LVEF ≤30% than in those with better LVEF. In the LVEF ≤30% group, cardiopulmonary arrest on arrival comprised 33% of all-cause deaths, and the survival curves at 2 years of the LVEF ≤30% group were almost compatible with those of the MADIT II ICD group.

CONCLUSIONS

In this subanalysis, LVD was less frequent than in Western countries. The annual death rate in JCAD was better than for the MADIT II ICD group. The prophylactic use of ICD seemed to be less effective than in Western countries but still expected to be useful for OMI patients with LVD in Japan.

Impact of pulmonary hypertension on gas exchange and exercise capacity in patients with pulmonary fibrosis

Pulmonary hypertension is a relevant interceding morbidity in patients with pulmonary fibrosis that has significant impact on exercise tolerance and outcome. The aim of this study was to further characterize the exercise intolerance, dyspnoea and ventilatory inefficiency of patients with pulmonary fibrosis in the presence or absence of pulmonary hypertension via cardiopulmonary exercise testing. Thirty-four patients underwent pulmonary function testing, symptom-limited exercise testing on a bicycle and dyspnoea evaluation according to the BORG scale. Pulmonary hypertension was assessed by echocardiography and in a subset of patient's right heart catheterization. Sixteen of 34 patients with pulmonary fibrosis revealed pulmonary hypertension. While all study patients did not differ in lung functions and demographic characteristics, patients suffering from pulmonary hypertension showed a significantly impaired exercise tolerance and worsened ventilatory inefficiency. The extent of pulmonary artery pressure elevation impacted significantly on ventilatory inefficiency. In addition, the increased ventilatory requirements significantly influenced the extent of dyspnoea in patients with pulmonary hypertension. We conclude that pulmonary hypertension has a significant impact on exercise capacity and dyspnoea in patients with interstitial lung disease (ILD). The further impairment of exercise capacity as well as the extent of dyspnoea in patients with interceding PHT is attributable to a significantly impaired ventilatory inefficiency.

Influence of the incremental step size in work rate on exercise response and gas exchange in patients with pulmonary hypertension

Background

Cardiopulmonary exercise testing (CPET) has become increasingly important as a routine procedure in daily clinical work. So far, it is generally accepted that an individualized exercise protocol with exercise duration of 6 to 12 minutes is preferable to assess maximal exercise performance. The aim of this study was to compare an individualized NYHA adapted exercise protocol with a fixed standard protocol in patients with severe pulmonary arterial hypertension.

Methods

Twenty-two patients (17 female, 5 male; mean age 49 ± 14 yrs) underwent symptom limited CPET on a bicycle. On two consecutive days each subject performed a stepwise CPET according to a modified Jones protocol (16 Watt per minute stages) as well as an individualized NYHA adapted protocol with 5 or 10 Watt/min stages in a randomized order. Oxygen uptake at peak exercise (peakVO₂) and anaerobic threshold (VO₂AT), maximal ventilation (VE), breathing reserve (VE/MVV), ventilatory efficiency (VE vs. VCO₂ slope), exercise time, maximal power and work rate were assessed and compared between both protocols.

Results

Comparing both, adapted NYHA protocol and standardized Jones protocol, we found significant differences in maximal power (56.7 ± 19 W vs. 74 ± 18 W; p < 0.001) and exercise time (332 ± 107 sec. vs. 248 ± 72 sec.; p < 0.001). In contrast, no significant differences were obvious comparing both protocols concerning work rate, VE, VE/MVV, peakVO₂, VO₂AT and VE vs. VCO₂ slope.

Conclusion

Variations of incremental step size during CPET significantly affect exercise time and maximal power, whereas relevant parameters for clinical judgement and prognosis such as oxygen uptake, ventilation and ventilatory efficiency remain unchanged. These findings have practical implications for the exercise evaluation of patients with pulmonary hypertension. To reach maximal results for ventilation, oxygen uptake and gas exchange an individualization of incremental step size appears not to be mandatory.

Temporal effects of low-dose ACE inhibition on endothelial function in Type 1 diabetic patients

AIM

Increased asymmetrical dimethylarginine (ADMA) is known to disturb endothelial function. ACE inhibitors decrease plasma ADMA levels in diseases associated with endothelial dysfunction. The effects of ACE inhibition on endothelial function and plasma ADMA levels in Type 1 diabetic patients was evaluated in the study.

METHODS

Thirty Type 1 diabetic patients [29+/-6 yr; females (F)/males (M): 18/12] and 29 controls (30+/-6 yr; F/M: 16/13) were recruited. Flow-mediated dilatation (FMD), plasma ADMAand thiobarbituric acid reactive substances (TBARs) were determined at baseline, on day 15 and 90 of 0.5 mg qd trandolapril therapy.

RESULTS

Compared to controls, baseline FMD levels were lower (4.7+/-2.0% vs 11.2+/-3.9%) (p<0.001), plasma ADMA (271.1+/-48.1 nmol/l vs 237.5+/-25.1 nmol/l) (p<0.05) and TBARs levels [4517.1+/-2366.9 nmol/malondialdehyde (MDA) vs 1775.9+/-598.7 nmol/MDA] (p<0.001) were higher in diabetic patients. On day 90 of trandolapril treatment, FMD (8.6+/-4.1%) (p<0.01) increased, ADMA levels (229.6+/-42.9 nmol/l) (p<0.001) decreased and TBARs levels (1531.8+/-1036.0 nmol/MDA) (p<0.001) decreased significantly. FMD was negatively correlated with plasma ADMA (r=-0.228, p<0.01), and TBARs levels (r=-0.244, p=0.02), whereas ADMA and TBARs levels were correlated positively (r=0.399, p<0.0001).

CONCLUSIONS

In conclusion, endothelial dysfunction is associated with elevated plasma ADMA levels in Type 1 diabetic patients. Low-dose ACE inhibition improves endothelial dysfunction and reduces ADMA levels. The antioxidant action of ACE inhibitors may play role in this process.

The revised role of ACE-inhibition after myocardial infarction in the thrombolytic/primary PCI era

Many studies have investigated the process of left ventricular (LV) dilatation and the effects of angiotensin-converting enzyme (ACE) inhibitors after myocardial infarction (MI). It has been generally accepted that progression of LV dilatation is a major predictor of heart failure and death after MI. Also, attenuation of LV dilatation is thought to be one of the main mechanisms by which ACE inhibitors (ACE-Is) produce their beneficial effects. However, evidence for this hypothesis came from studies that were performed before thrombolytic therapy and primary percutaneous coronary intervention (PCI) were routinely used after acute MI. Nowadays, reperfusion is obtained much more frequently and LV dilatation after MI has become less prevalent. Nevertheless, ACE-Is proved effective in reducing cardiac morbidity and mortality. Therefore, mechanisms other than attenuation of LV dilatation, such as anti-atherosclerotic effects or plaque stabilisation, may explain the long-term beneficial effects of ACE-Is after MI. In the present overview, we evaluate the role of LV dilatation and the effects of ACE-Is after MI in the thrombolytic/primary PCI era and provide recommendations on ACE-I use in clinical practice.

Effects of early and late administration of angiotensin-converting enzyme inhibitors on mortality after myocardial infarction

BACKGROUND

Clinical trials demonstrating that angiotensin-converting enzyme (ACE) inhibitors reduce mortality when prescribed following myocardial infarction have focused on either early or late administration. It is unclear what the overall mortality benefits are and how long they last.

METHODS

We identified trials of ACE inhibitor therapy after myocardial infarction that were published between 1987 and 2002. Studies were included if they were randomized placebo-controlled trials with follow-up of at least 1 month. Separate analyses were performed for trials of therapy initiated within 48 hours of infarction (early administration) or initiated more than 48 hours after infarction (late administration). The Yusuf-Peto modification of the Mantel-Haenszel method was used to obtain summary odds ratios for mortality.

RESULTS

Twenty-two trials (14 early administration, 8 late administration) met the inclusion criteria. Early administration of ACE inhibitors was associated with a slight reduction in 1-month mortality (odds ratio [OR] = 0.93; 95% confidence interval [CI]: 0.88 to 0.97) and a much larger reduction in 1-year mortality (OR = 0.68; 95% CI: 0.54 to 0.87). Late therapy was associated with significant reductions in 1-year mortality (OR = 0.84; 95% CI: 0.73 to 0.97), 2-year mortality (OR = 0.75; 95% CI: 0.67 to 0.85), and 3-year mortality (OR = 0.74; 95% CI: 0.65 to 0.84).

CONCLUSION

Both early and late administration of ACE inhibitor therapy are associated with lower mortality following myocardial infarction, with the largest benefits observed with long-term mortality.

Drug Therapy for Prevention of Recurrent Myocardial Infarction

OBJECTIVE

To provide an evidence-based overview of drug treatment for long-term secondary prevention of myocardial infarction (MI).

DATA SOURCES

We conducted searches of MEDLINE (1966-August 2002), the Cochrane Controlled Trial Register, and the reference list of each identified study.

STUDY SELECTION/DATA EXTRACTION

Trials and meta-analyses were included using the following criteria: (1) randomized trials, (2) description of identification procedure, inclusion criteria, outcome measures, and statistical methods, (3) confirmed MIs, (4) treatment continued for at least 1 month, and (5) all-cause mortality as primary outcome; other events as secondary outcomes. All authors interpreted the results from trials that met the inclusion criteria.

DATA SYNTHESIS

In randomized clinical trials, low-dose aspirin, high-intensity oral anticoagulants, beta-blockers, angiotensin-converting enzyme (ACE) inhibitors, and statins decreased the risk of mortality and reinfarction after MI. Randomized clinical trials using calcium-channel blockers, antiarrhythmics, and hormone replacement therapy did not show benefits in patients with prior MI. Effects of the combined use of aspirin or oral anticoagulants with beta-blockers or ACE inhibitors plus statins must be derived from subgroup analysis of trials, but seem to be beneficial.

CONCLUSIONS

The use of at least aspirin or an oral anticoagulant, a beta-blocker or an ACE inhibitor, plus a statin should be incorporated in the treatment routine. Clopidogrel treatment might be an alternative to aspirin. Standard addition of a beta-blocker to ACE inhibitor-treated patients without reduced left-ventricular ejection fraction seems to be untimely.

Approaches to statistical analysis of repeated echocardiographic measurements after myocardial infarction and its relation to heart failure: Application of a random-effects model

BACKGROUND

Extensive left ventricular (LV) dilatation after myocardial infarction (MI) is associated with increased heart failure risk.

AIMS

To investigate whether the power to demonstrate the relation between LV dilatation and heart failure depends on the method applied to predict LV dilatation after MI.

METHODS

A random-effects model and ANOVA model for repeated measurements (MANOVA) were applied to predict LV volume index during 1 year for 298 post-MI patients. Spearman correlation coefficients (r) were calculated and Cox regression analysis was used to calculate risk ratio's (RR).

RESULTS

LV volume indices were more accurately predicted by a random-effects model than by a MANOVA model (systolic/diastolic respectively r = 0.93/0.91 vs. r = 0.67/0.64). Furthermore, patients with high LV volume index as predicted by the random-effects model, had significantly increased heart failure risk (systolic RR 2.04 (95% CI: 1.31 to 3.17; P = 0.001), diastolic RR 1.80 (95% CI: 1.16 to 2.78; P = 0.007). Using the same data, MANOVA failed to demonstrate this relation significantly (systolic RR 1.77 (95% CI: 0.79 to 3.98; P = 0.16), diastolic RR 1.49 (95% CI: 0.68 to 3.30; P = 0.31).

CONCLUSION

When analyzing repeated measurement data, random-effect models are more powerful in detecting clinical relations than are MANOVA models, especially in the presence of missing values.

Adynamic cardiomyoplasty: effect on cardiac efficiency and contractile reserve in dogs with adriamycin-induced cardiomyopathy

The girdling effect of the skeletal muscle wrap seems to be the primary mechanism of action of cardiomyoplasty. It is associated with a myocardial sparing effect. Myocardial sparing effect has been shown with an active muscle wrap or an active muscle wrap acutely turned "OFF". The purpose of the study was to evaluate the effect of a passive skeletal muscle wrap on cardiac energetics parameters and contractile reserve in a canine model of cardiomyopathy. Six dogs with adriamycin-induced cardiomyopathy were studied. Three dogs underwent right latissimus dorsi adynamic cardiomyoplasty and 3 served as controls. Cardiac and coronary sinus catheterizations were performed at 0 and 6 weeks. A dobutamine stress test was performed at 6 weeks. Myocardial oxygen consumption was not reduced in the cardiomyoplasty group (139.20+/-86.90 Joules/min) compared to the control group (95.10+/-12.60 Joules/min, P = 0.27) at 6 weeks. Mechanical cardiac efficiency was increased in the cardiomyoplasty group (33.15+/-4.40%) compared to the control group (24.50+/-2.70%, P = 0.049) at 6 weeks. Left ventricular end diastolic diameter index was reduced in the cardiomyoplasty group (38.00+/-1.70 mm/m2) compared to the control group (46.30+/-1.55 mm/m2, P = 0.049) at 6 weeks. Indices of diastolic function -dp/dt, and tau were not significantly affected by adynamic cardiomyoplasty. Max dp/dt was increasing more in the cardiomyoplasty group than in the control group (P = 0.07) during dobutamine stress test. Mechanical cardiac efficiency was better preserved by the adynamic cardiomyoplasty. Myocardial contractile reserve might be better preserved with cardiomyoplasty.

Effect of angiotensin converting enzyme inhibition on sudden cardiac death in patients following acute myocardial infarction. A meta-analysis of randomized clinical trials

Estimate the effect of angiotensin converting enzyme (ACE) inhibitors on the risk of sudden cardiac death (SCD) following myocardial infarction (MI).

BACKGROUND

Trials in post-MI patients have shown that ACE inhibitor therapy reduces mortality. However, the effect on SCD as a mechanism has not been clarified.

METHODS

Trials of ACE inhibitor therapy following MI reported between January, 1978 and August, 1997 were identified. Studies were included if they met the following criteria: 1) randomized comparison of ACE inhibitor to placebo within 14 days of MI; 2) study duration/blinded follow-up of > or =6 weeks; 3) the number of deaths and modes of death were reported or could be obtained from the investigators.

RESULTS

We identified 374 candidate articles, of which 15 met the inclusion criteria. The 15 trials included 15,104 patients, 2,356 of whom died. Most (87%) fatalities were cardiovascular and 900 were SCDs. A significant reduction in SCD risk or a trend towards this was observed in all of the larger (N > 500) trials. Overall, ACE inhibitor therapy resulted in significant reductions in risk of death (random effects odds ratio [OR] = 0.83; 95% confidence interval [CI] 0.71-0.97), cardiovascular death (OR = 0.82; 95% CI 0.69-0.97) and SCD (OR = 0.80; 95% CI 0.70-0.92).

CONCLUSIONS

This analysis is consistent with prior reports showing that ACE inhibitors decrease the risk of death following a recent MI by reducing cardiovascular mortality. Moreover, this analysis suggests that a reduction in SCD risk with ACE inhibitors is an important component of this survival benefit.