Outcome of patients with congestive heart failure treated with standard versus high doses of enalapril: a multicenter study. High Enalapril Dose Study Group

1821-2021: Contributions of physicians and researchers of Greek descent in the advancement of clinical and experimental cardiology and cardiac surgery

While the role of Greeks in the development of early western medicine is well-known and appreciated, the contributions of modern Greek medical practitioners are less known and often overlooked. On the occasion of the 200-year anniversary of the Greek War of Independence, this review article sheds light onto the achievements of modern scientists of Greek descent in the development of cardiology, cardiac surgery, and cardiovascular research, through a short history of the development of these fields and of the related institutions in Greece. In the last decades, the Greek cardiology and Cardiac Surgery communities have been active inside and outside Greece and have a remarkable presence internationally, particularly in the United States. This article highlights the ways in which Greek cardiology and cardiovascular research has been enriched by absorbing knowledge produced in international medical centers, academic institutes and pharmaceutical industries in which generations of Greek doctors and researchers trained prior to their return to the homeland; it also highlights the achievements of medical practitioners and researchers of Greek descent who excelled abroad, producing ground-breaking work that has left a permanent imprint on global medicine.

Association between dosing and combination use of medications and outcomes in heart failure with reduced ejection fraction: data from the Swedish Heart Failure Registry

AIMS

To assess the association between combination, dose and use of current guideline-recommended target doses (TD) of renin-angiotensin system inhibitors (RASi), angiotensin receptor-neprilysin inhibitors (ARNi) and β-blockers, and outcomes in a large and unselected contemporary cohort of patients with heart failure (HF) and reduced ejection fraction.

METHODS AND RESULTS

Overall, 17 809 outpatients registered in the Swedish Heart Failure Registry (SwedeHF) from May 2000 to December 2018, with ejection fraction <40% and duration of HF ≥90 days were selected. Primary outcome was a composite of time to cardiovascular death and first HF hospitalization. Compared with no use of RASi or ARNi, the adjusted hazard ratio (HR) (95% confidence interval [CI]) was 0.83 (0.76-0.91) with <50% of TD, 0.78 (0.71-0.86) with 50%-99%, and 0.73 (0.67-0.80) with ≥100% of TD. Compared with no use of β-blockers, the adjusted HR (95% CI) was 0.86 (0.76-0.91), 0.81 (0.74-0.89) and 0.74 (0.68-0.82) with <50%, 50%-99% and ≥100% of TD, respectively. Patients receiving both an angiotensin-converting enzyme inhibitor (ACEi)/angiotensin receptor blocker (ARB)/ARNi and a β-blocker at 50%-99% of TD had a lower adjusted risk of the primary outcome compared with patients only receiving one drug, i.e. ACEi/ARB/ARNi or β-blocker, even if this was at ≥100% of TD.

CONCLUSION

Heart failure with reduced ejection fraction patients using higher doses of RASi or ARNi and β-blockers had lower risk of cardiovascular death or HF hospitalization. Use of two drug classes at 50%-99% of TD dose was associated with lower risk than one drug class at 100% of TD.

Drug therapy for HFrEF: What is the "right" dose?

New guidelines have emphasized the primacy of starting the four key life‐saving therapies for patients with heart failure and reduced ejection fraction as quickly as possible, with titration to ‘target dose’ of these, as secondary consideration. In this article, we examine the reasons for this change in emphasis and revisit the evidence regarding the dosing of pharmacological therapy in heart failure. We demonstrate the early benefits obtained with even low doses of most of the foundational therapies for heart failure and reduced ejection fraction. We also clarify that the ‘target dose’ of those therapies requiring titration was a goal based on tolerability and often not reached in trials, i.e. the proven benefits of our foundational therapies were demonstrated with an average dose that was less than target and many patients in these trials were treated with sub‐target doses.

Impact of a pharmacist-based multidimensional intervention aimed at decreasing the risk of hyperkalemia in heart failure patients: A Latin-American experience

AIMS

Hyperkalemia is a potentially life-threatening condition associated with the use of heart failure (HF) medications, which can lead to increased morbidity and mortality. Novel approaches for hyperkalemia prevention are needed, especially in limited-resource settings. Despite multiple studies showing the beneficial impact of pharmaceutical-counseling in several outcomes, there is a knowledge-gap regarding its impact on hyperkalemia prevention.

METHODS

A case-control study was performed in patients from the Adult Heart Failure Clinic Registry in our institution. Cases were selected using a definition of serum potassium K+ ≥5.5 mmol/L. To study the association between hyperkalemia and relevant risk factors, we performed a multivariate logistic regression analysis using the Least Absolute Shrinkage and Selection Operator (LASSO) method for variable selection. We also fitted a Classification and Regression Tree (CART) to establish complex interactions and effect modifiers between the selected variables.

RESULTS

We matched 483 controls (eligible HF patients without hyperkalemia) to 132 cases (eligible HF patients with hyperkalemia based on age and calendar, yielding a total sample size of 615 patients (270 females) for this study. Cases had statistically significant lower odds of receiving a pharmacist-based multidimensional intervention (PBMI) (OR 0.57; 95% CI, 0.43-0.80) or having HF with reduced ejection fraction (OR 0.56; 95% CI, 0.18-0.72). On the other hand, patients who presented hyperkalemia had statistically significant higher odds of having a history of chronic kidney disease stage 4 (OR 4.97; 95% CI, 2.24-11.01) or 5 (OR 6.73; 95% CI, 1.69-26.84) and being on enalapril at doses =40 mg/day (OR, 9.90; 95% CI 5.81-16.87).

CONCLUSIONS

PBMI is a practical approach to prevent hyperkalemia in HF patients in a limited-resource setting. However, clinical trials are needed to assess its effectiveness.

High-dose versus low-dose angiotensin converting enzyme inhibitors in heart failure: systematic review and meta-analysis

OBJECTIVE

To systematically review evidence comparing the effect of low-dose versus high-dose ACE inhibitors (ACEIs) on all-cause and cardiovascular mortality and hospitalisation, functional capacity and side effects in patients with heart failure (HF).

METHODS

We searched PubMed, Embase, Cochrane CENTRAL and LILACS up to January 2019. We included randomised controlled trials (RCTs) comparing low-dose versus high-dose ACEIs in adults with HF with reduced left ventricular ejection fraction (HFrEF). Study selection and data extraction were performed by two independent reviewers. Risk of bias was assessed with RoB 2.0, and quality of evidence with Grading of Recommendations Assessment, Development and Evaluation (GRADE). We conducted random effects meta-analysis and trial sequential analysis.

RESULTS

We included eight RCTs (5829 patients with HF). In comparison with low-dose ACEIs, high-dose ACEIs showed a non-significant effect on all-cause mortality (8 RCTs, n=5828, relative risk (RR) 0.95, 95% CI 0.88 to 1.02; moderate quality of evidence), cardiovascular mortality (6 RCTs, n=4048, RR 0.93, 95% CI 0.85 to 1.01; moderate quality of evidence), all-cause hospitalisation (5 RCTs, n=5394, RR 0.95, 95% CI 0.82 to 1.10; moderate quality of evidence) and cardiovascular hospitalisation (4 RCTs, n=5242, RR 0.98, 95% CI 0.83 to 1.17; low quality of evidence). High-dose ACEI increased functional capacity (4 studies, n=555, standardised mean difference 0.38, 95% CI 0.20 to 0.55; low quality of evidence) and the risk of hypotension (4 RCTs, n=3783, RR 1.64, 95% CI 1.30 to 2.05; moderate quality of evidence). High-dose ACEI had no effect on dizziness (3 RCTs, n=4994, RR 1.37, 95% CI 0.97 to 1.93; low quality of evidence), but decreased the risk of cough (4 RCTs, n=5146, RR 0.85, 95% CI 0.73 to 0.98; moderate quality of evidence).

CONCLUSIONS

The magnitude of benefit of using high dose versus low to intermediate doses of ACEIs might be less than traditionally suggested in clinical guidelines. These findings might help clinicians address the complex task of HF management in a more rational and timely fashion, saving efforts to implement strategies with the greatest net clinical benefit.

Higher versus lower doses of ACE inhibitors, angiotensin-2 receptor blockers and beta-blockers in heart failure with reduced ejection fraction: Systematic review and meta-analysis

Background

Current heart failure (HF) guidelines recommend titrating angiotensin-converting enzyme inhibitors (ACEIs)/angiotensin receptor blockers (ARBs) and beta-blockers (BBs) to target doses used in pivotal placebo-controlled randomized controlled trials (RCTs). Despite a number of RCTs comparing different doses (i.e. higher versus lower doses) of ACEIs, ARBs and BBs, the effects of higher versus lower doses on efficacy and safety remains unclear. For this reason, we performed a systematic review and meta-analysis to evaluate the efficacy and safety of higher versus lower doses of ACEIs, ARBs and BBs in patients with HFrEF.

Methods

We searched MEDLINE, Embase and the Cochrane Central Register of Controlled Trials (CENTRAL) via Ovid from inception to April 25^th, 2018 and opentrials.net and clinicaltrials.gov for relevant trials that compared different doses of medications in heart failure. We analyzed trials by drug class (ACEIs, ARBs, and BBs) for efficacy outcomes (all-cause mortality, cardiovascular mortality, all-cause hospitalizations, HF hospitalizations, HF worsening). For safety outcomes, we pooled trials within and across drug classes.

Results

Our meta-analysis consisted of 14 RCTs. Using GRADE criteria, the quality of evidence for ACEIs and ARBs was assessed as generally moderate for efficacy and high for adverse effects, whereas overall quality for BBs was very low to low. Over ~2–4 years higher versus lower doses of ACEIs, ARBs or BBs did not significantly reduce all-cause mortality [ACEIs relative risk (RR) 0.94 (95% confidence interval 0.87–1.02)], ARBs RR 0.96 (0.87–1.04), BBs RR 0.25 (0.06–1.01)] or all cause hospitalizations [ACEIs relative risk (RR) 0.94 (95% confidence interval 0.86–1.02)], ARBs RR 0.98 (0.93–1.04), BBs RR 0.93 (0.39–2.24)]. However, all point estimates favoured higher doses. Higher doses of ARBs significantly reduced hospitalization for HF [RR 0.89 (0.80–0.99)– 2.8% ARR], and higher doses of ACEIs and ARBs significantly reduced HF worsening [RR 0.85 (0.79–0.92)– 5.1% ARR and 0.91 (0.84–0.99)– 3.2% ARR, respectively] compared to lower doses. None of the differences between higher versus lower doses of BBs were significant; however, precision was low. Higher doses of these medications compared to lower doses increased the risk of discontinuation due to adverse events, hypotension, dizziness, and for ACEIs and ARBs, increased hyperkalemia and elevations in serum creatinine. Absolute increase in harms for adverse effects ranged from ~ 3 to 14%.

Conclusions

Higher doses of ACEIs and ARBs reduce the risk of HF worsening compared to lower doses, and higher doses of ARBs also reduce the risk of HF hospitalization but the evidence is sparse and imprecise. Higher doses increase the chance of adverse effects compared to lower doses. Evidence for BBs is inconclusive. These results support initially always starting at low doses of ACEIs/ARBs and only titrating the dose up if the patient tolerates dose increases.

Was the Enalapril Dose Too Low in the PARADIGM-HF Trial?

Heart failure (HF) is a common clinical syndrome associated with significant morbidity and mortality, and there remains a clear need for innovative therapies that can modify disease progression. Sacubitril/valsartan (LCZ696) is a novel complex that combines simultaneous neprilysin inhibition and angiotensin II receptor blockade, that has demonstrated significant cardiovascular death or HF hospitalization reduction in the Prospective Comparison of Angiotensin Receptor/Neprilysin Inhibitor (ARNI) With Angiotensin-Converting Enzyme (ACE) Inhibitors to Determine Impact on Global Mortality and Morbidity in Heart Failure (PARADIGM-HF) trial when compared with evidence-based doses of the gold standard ACE inhibitor enalapril. In this comprehensive review, the authors discuss historical trials that have investigated clinical outcomes utilizing variable dosing levels of ACE inhibitors or angiotensin receptor blockers in patients with HF with reduced ejection fraction. A critical analysis of the highlighted studies is proposed in the context of current HF management guidelines and HF clinical practice. In conclusion, based on current evidence, it is unclear whether a maximum recommended enalapril dose would promote improved patient outcomes compared with an intermediate dose. However, no prospective study to date comparing ACE inhibitor doses has documented that higher doses result in significant mortality reduction, although the data suggest that there may be a decrease in HF hospitalizations when compared with lower doses.

Prognostic Implications of Changes in N-Terminal Pro-B-Type Natriuretic Peptide in Patients With Heart Failure

BACKGROUND

Natriuretic peptides (NP) have prognostic value in heart failure (HF), although the clinical importance of changes in NP from baseline is unclear.

OBJECTIVES

The authors assessed whether a reduction in N-terminal pro-B-type NP (NT-proBNP) was associated with a decrease in HF hospitalization and cardiovascular mortality (primary endpoint) in patients with HF and reduced ejection fraction, whether treatment with sacubitril/valsartan reduced NT-proBNP below specific partition values more than enalapril, and whether the relationship between changes in NT-proBNP and changes in the primary endpoint were dependent on assigned treatment.

METHODS

In PARADIGM-HF (Prospective Comparison of ARNI [Angiotensin Receptor-Neprilysin Inhibitor] with ACEI [Angiotensin-Converting-Enzyme Inhibitor] to Determine Impact on Global Mortality and Morbidity in Heart Failure Trial), baseline NT-proBNP was measured in 2,080 patients; 1,292 had baseline values >1,000 pg/ml and were reassessed at 1 and 8 months. We related change in NT-proBNP to outcomes.

RESULTS

One month after randomization, 24% of the baseline NT-proBNP levels >1,000 pg/ml had fallen to ≤1,000 pg/ml. Risk of the primary endpoint was 59% lower in patients with a fall in NT-proBNP to ≤1,000 pg/ml than in those without such a fall. In sacubitril/valsartan-treated patients, median NT-proBNP was significantly lower 1 month after randomization than in enalapril-treated patients, and it fell to ≤1,000 pg/ml in 31% versus 17% of patients treated with sacubitril/valsartan and enalapril, respectively. There was no significant interaction between treatment and the relationship between change in NT-proBNP and the subsequent risk of the primary endpoint.

CONCLUSIONS

Patients who attained a significant reduction in NT-proBNP had a lower subsequent rate of cardiovascular death or HF hospitalization independent of the treatment group. Treatment with sacubitril/valsartan was nearly twice as likely as enalapril to reduce NT-proBNP to values ≤1,000 pg/ml. (Prospective Comparison of ARNI [Angiotensin Receptor-Neprilysin Inhibitor] with ACEI [Angiotensin-Converting-Enzyme Inhibitor] to Determine Impact on Global Mortality and Morbidity in Heart Failure Trial) [PARADIGM-HF]; NCT01035255.).

Importance of endogenous compensatory vasoactive peptides in broadening the effects of inhibitors of the renin-angiotensin system for the treatment of heart failure

The magnitude of the clinical benefits produced by inhibitors of the renin-angiotensin system in heart failure has been modest, possibly because of the ability of renin-angiotensin activity to escape from suppression during long-term treatment. Efforts to intensify pharmacological blockade by use of dual inhibitors that interfere with the renin-angiotensin system at multiple sites have not yielded consistent incremental clinical benefits, but have been associated with serious adverse reactions. By contrast, potentiation of endogenous compensatory vasoactive peptides can act to enhance the survival effects of inhibitors of the renin-angiotensin system, as evidenced by trials that have compared angiotensin-converting enzyme inhibitors with drugs that inhibit both the renin-angiotensin system and neprilysin. Several endogenous vasoactive peptides act as adaptive mechanisms, and their augmentation could help to broaden the benefits of renin-angiotensin system inhibitors for patients with heart failure.

Spotlight on valsartan-sacubitril fixed-dose combination for heart failure: the evidence to date

Heart failure is a global problem with elevated prevalence, and it is associated with substantial cardiovascular morbidity and mortality. Treating heart-failure patients has been a very challenging task. This review highlights the main pharmacological developments in the field of heart failure with reduced ejection fraction, giving emphasis to a drug that has a dual-acting inhibition of the neprilysin and renin–angiotensin–aldosterone system. Neprilysin is an enzyme that participates in the breakdown of biologically active natriuretic peptides and several other vasoactive compounds. The inhibition of neprilysin has been a therapeutic target for several drugs tested in cardiovascular disease, mainly for heart failure and/or hypertension. However, side effects and a lack of efficacy led to discontinuation of their development. LCZ696 is a first-in-class neprilysin- and angiotensin-receptor inhibitor that has been developed for use in heart failure. This drug is composed of two molecular moieties in a single crystalline complex: a neprilysin-inhibitor prodrug (sacubitril) and the angiotensin-receptor blocker (valsartan). The PARADIGM-HF trial demonstrated that this drug was superior to an angiotensin-converting enzyme inhibitor (enalapril) in reducing mortality in patients with heart failure with reduced ejection fraction. The ability to block the angiotensin receptor and augment the endogenous natriuretic peptide system provides a distinctive mechanism of action in cardiovascular disease.

New-onset left bundle branch block-associated idiopathic nonischemic cardiomyopathy and left ventricular ejection fraction response to guideline-directed therapies: The NEOLITH study

BACKGROUND

Left ventricular ejection fraction (LVEF) response to guideline-directed medical therapy (GDMT) and to early cardiac resynchronization therapy (CRT) in new-onset idiopathic nonischemic cardiomyopathy (NICM) and left bundle branch block (LBBB) is not well described. CRT is recommended if LVEF remains ≤35% after at least 3 months of GDMT.

OBJECTIVE

The purpose of this study was to describe LVEF response to GDMT at 3 months and to early CRT in new-onset LBBB-associated idiopathic NICM.

METHODS

A retrospective cohort study was performed in subjects with new-onset idiopathic NICM, LVEF ≤35%, and LBBB or narrow (<120 ms) QRS complex morphology. LVEF response between groups was evaluated with log-binomial and linear regression. LVEF response within groups was evaluated using the paired Student t test.

RESULTS

In 102 subjects (70 with narrow QRS complex and 32 with LBBB), post-GDMT LVEF was >35% in 39 narrow QRS complex subjects (56%) and 2 LBBB subjects (6%) (P < .0001). The absolute difference between post-GDMT LVEF and initial LVEF was greater in the narrow QRS complex group (16.1% ± 14.6% vs. 3.3% ± 10.7%; P < .0001). Narrow QRS complex, referenced to LBBB, was significantly associated with post-GDMT LVEF >35% (relative risk 10.30; 95% confidence interval 2.63-40.27; P = .0008) and absolute difference between post-GDMT LVEF and initial LVEF (β = 16.296; standard error = 2.977; P < .0001) in final multivariable analyses. CRT super-response, defined as post-CRT LVEF ≥50%, was observed in 8 of LBBB subjects (35%) who received CRT.

CONCLUSION

GDMT did not significantly improve LVEF in new-onset LBBB-associated idiopathic NICM at 3 months. Most remained candidates for CRT, and a high percentage were super-responders. Optimal timing for CRT implantation requires further investigation.

Angiotensin receptor neprilysin inhibition compared with enalapril on the risk of clinical progression in surviving patients with heart failure

BACKGROUND

Clinical trials in heart failure have focused on the improvement in symptoms or decreases in the risk of death and other cardiovascular events. Little is known about the effect of drugs on the risk of clinical deterioration in surviving patients.

METHODS AND RESULTS

We compared the angiotensin-neprilysin inhibitor LCZ696 (400 mg daily) with the angiotensin-converting enzyme inhibitor enalapril (20 mg daily) in 8399 patients with heart failure and reduced ejection fraction in a double-blind trial. The analyses focused on prespecified measures of nonfatal clinical deterioration. In comparison with the enalapril group, fewer LCZ696-treated patients required intensification of medical treatment for heart failure (520 versus 604; hazard ratio, 0.84; 95% confidence interval, 0.74-0.94; P=0.003) or an emergency department visit for worsening heart failure (hazard ratio, 0.66; 95% confidence interval, 0.52-0.85; P=0.001). The patients in the LCZ696 group had 23% fewer hospitalizations for worsening heart failure (851 versus 1079; P<0.001) and were less likely to require intensive care (768 versus 879; 18% rate reduction, P=0.005), to receive intravenous positive inotropic agents (31% risk reduction, P<0.001), and to have implantation of a heart failure device or cardiac transplantation (22% risk reduction, P=0.07). The reduction in heart failure hospitalization with LCZ696 was evident within the first 30 days after randomization. Worsening of symptom scores in surviving patients was consistently more common in the enalapril group. LCZ696 led to an early and sustained reduction in biomarkers of myocardial wall stress and injury (N-terminal pro-B-type natriuretic peptide and troponin) versus enalapril.

CONCLUSIONS

Angiotensin-neprilysin inhibition prevents the clinical progression of surviving patients with heart failure more effectively than angiotensin-converting enzyme inhibition.

CLINICAL TRIAL REGISTRATION URL

http://www.clinicaltrials.gov. Unique identifier: NCT01035255.

Uptitration of renin-angiotensin system blocker and beta-blocker therapy in patients hospitalized for heart failure with reduced versus preserved left ventricular ejection fractions

In ambulatory patients with heart failure (HF) and reduced ejection fraction (rEF), renin-angiotensin system (RAS) and β-blockers at guideline-recommended target dose reduce all-cause mortality and readmissions. Benefits in HF with preserved ejection fraction (pEF), as well as uptitration after a hospitalization, remain uncertain. This study assesses the impact of RAS- and β-blocker uptitrations in patients with HFrEF versus HFpEF during and immediately after a hospital admission. In consecutive patients (209 HFrEF with left ventricular ejection fraction <40% and 108 HFpEF with left ventricular ejection fraction ≥40%), RAS- and β-blocker dose changes were followed during 6 months after an index HF hospitalization. Patients with a RAS- and β-blocker dose increase of ≥10% of the recommended target dose were compared with patients without uptitration. Patients who received uptitration were significantly younger, with a higher heart rate and better renal function, and received spironolactone more often. Both RAS- and β-blocker uptitrations were associated with significant reductions in the composite end-point of all-cause mortality or HF readmissions in HFrEF (hazard ratio [HR] 0.36, 95% confidence interval [CI] 0.22 to 0.60 and HR 0.51, 95% CI 0.32 to 0.81, respectively). After correction for age, heart rate, blood pressure, renal function, and spironolactone use, this association remained significant for RAS blockers (HR 0.54, 95% CI 0.31 to 0.93, p = 0.027) but not for β-blockers (HR 0.65, 95% CI 0.39 to 1.09, p = 0.101). No benefit of RAS- or β-blocker uptitration was observed in HFpEF. In conclusion, uptitration of neurohumoral blockers after an HF hospitalization is more frequently performed in younger patients with low co-morbidity burden. RAS-blocker uptitration independently predicts clinical outcome in patients with HFrEF but not in those with HFpEF.

Dual angiotensin receptor and neprilysin inhibition as an alternative to angiotensin-converting enzyme inhibition in patients with chronic systolic heart failure: rationale for and design of the Prospective comparison of ARNI with ACEI to Determine Impact on Global Mortality and morbidity in Heart Failure trial (PARADIGM-HF)

AIMS

Although the focus of therapeutic intervention has been on neurohormonal pathways thought to be harmful in heart failure (HF), such as the renin-angiotensin-aldosterone system (RAAS), potentially beneficial counter-regulatory systems are also active in HF. These promote vasodilatation and natriuresis, inhibit abnormal growth, suppress the RAAS and sympathetic nervous system, and augment parasympathetic activity. The best understood of these mediators are the natriuretic peptides which are metabolized by the enzyme neprilysin. LCZ696 belongs to a new class of drugs, the angiotensin receptor neprilysin inhibitors (ARNIs), which both block the RAAS and augment natriuretic peptides.

METHODS

Patients with chronic HF, NYHA class II-IV symptoms, an elevated plasma BNP or NT-proBNP level, and an LVEF of ≤40% were enrolled in the Prospective comparison of ARNI with ACEI to Determine Impact on Global Mortailty and morbidity in Heart Failure trial (PARADIGM-HF). Patients entered a single-blind enalapril run-in period (titrated to 10 mg b.i.d.), followed by an LCZ696 run-in period (100 mg titrated to 200 mg b.i.d.). A total of 8436 patients tolerating both periods were randomized 1:1 to either enalapril 10 mg b.i.d. or LCZ696 200 mg b.i.d. The primary outcome is the composite of cardiovascular death or HF hospitalization, although the trial is powered to detect a 15% relative risk reduction in cardiovascular death.

PERSPECTIVES

PARADIGM-HF will determine the place of the ARNI LCZ696 as an alternative to enalapril in patients with systolic HF. PARADIGM-HF may change our approach to neurohormonal modulation in HF.

TRIAL REGISTRATION

NCT01035255.

Fast parameters estimation in medication efficacy assessment model for heart failure treatment

INTRODUCTION

Heart failure (HF) is a common and potentially fatal condition. Cardiovascular research has focused on medical therapy for HF. Theoretical modelling could enable simulation and evaluation of the effectiveness of medications. Furthermore, the models could also help predict patients' cardiac response to the treatment which will be valuable for clinical decision-making.

METHODS

This study presents a fast parameters estimation algorithm for constructing a cardiovascular model for medicine evaluation. The outcome of HF treatment is assessed by hemodynamic parameters and a comprehensive index furnished by the model. Angiotensin-converting enzyme inhibitors (ACEIs) were used as a model drug in this study.

RESULTS

Our simulation results showed different treatment responses to enalapril and lisinopril, which are both ACEI drugs. A dose-effect was also observed in the model simulation.

CONCLUSIONS

Our results agreed well with the findings from clinical trials and previous literature, suggesting the validity of the model.

Contemporary medical management of systolic heart failure

Pharmacological therapy of systolic left ventricular dysfunction has evolved over the past 3 decades. Current therapy is focused primarily on the regulation of the renin-angiotensin-aldosterone axis and sympathetic nervous system. Additional targets of pharmacotherapy include vasoconstriction, impaired nitric oxide metabolism, inflammation and improving myocardial function. As therapies in chronic systolic heart failure have evolved beyond diuretics and digoxin, so too has mortality improved. Future directions in the management of heart failure include cell-based and genetic therapy, and further refinement of current therapy through genetics.

Update on Renin-Angiotensin-aldosterone blockade in heart failure

There is convincing evidence that the renin-angiotensin-aldosterone system (RAAS) plays an important role in heart failure (HF), from the events that result in its inception through advanced disease. In particular, RAAS activation is one of the major pathways involved in maladaptive cardiac remodeling, a process that results in progressive cardiac dysfunction. Not surprisingly, strategies targeting the RAAS have substantial benefits in HF. These therapies, which include angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and aldosterone receptor antagonists, have emerged as cornerstones of HF therapy, particularly in patients with systolic dysfunction. Their role in HF with preserved ejection fraction, however, is less certain. New information and approaches targeting RAAS activation continue to emerge. Direct renin inhibitors are hypothesized to have beneficial effects in HF, but further studies are needed to evaluate their efficacy.

Effects of high-dose versus low-dose losartan on clinical outcomes in patients with heart failure (HEAAL study): a randomised, double-blind trial

BACKGROUND

Angiotensin-receptor blockers (ARBs) are effective treatments for patients with heart failure, but the relation between dose and clinical outcomes has not been explored. We compared the effects of high-dose versus low-dose losartan on clinical outcomes in patients with heart failure.

METHODS

This double-blind trial was undertaken in 255 sites in 30 countries. 3846 patients with heart failure of New York Heart Association class II-IV, left-ventricular ejection fraction 40% or less, and intolerance to angiotensin-converting-enzyme (ACE) inhibitors were randomly assigned to losartan 150 mg (n=1927) or 50 mg daily (n=1919). Allocation was by block randomisation stratified by centre and presence or absence of beta-blocker therapy, and all patients and investigators were masked to assignment. The primary endpoint was death or admission for heart failure. Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00090259.

FINDINGS

Six patients in each group were excluded because of poor data quality. With 4.7-year median follow-up in each group (IQR 3.7-5.5 for losartan 150 mg; 3.4-5.5 for losartan 50 mg), 828 (43%) patients in the 150 mg group versus 889 (46%) in the 50 mg group died or were admitted for heart failure (hazard ratio [HR] 0.90, 95% CI 0.82-0.99; p=0.027). For the two primary endpoint components, 635 patients in the 150 mg group versus 665 in the 50 mg group died (HR 0.94, 95% CI 0.84-1.04; p=0.24), and 450 versus 503 patients were admitted for heart failure (0.87, 0.76-0.98; p=0.025). Renal impairment (n=454 vs 317), hypotension (203 vs 145), and hyperkalaemia (195 vs 131) were more common in the 150 mg group than in the 50 mg group, but these adverse events did not lead to significantly more treatment discontinuations in the 150 mg group.

INTERPRETATION

Losartan 150 mg daily reduced the rate of death or admission for heart failure in patients with heart failure, reduced left-ventricular ejection fraction, and intolerance to ACE inhibitors compared with losartan 50 mg daily. These findings show the value of up-titrating ARB doses to confer clinical benefit.

FUNDING

Merck (USA).

Traditional and novel approaches to management of heart failure: successes and failures

Although considerable progress has been made in the pharmacologic and device management of chronic heart failure in recent decades, heart failure patients continue to remain symptomatic, with high hospitalization and mortality rates. A number of novel agents, including endothelin antagonists and tumor-necrosis factor blockers, have recently failed to improve the clinical outcomes of patients with heart failure. Have we reached a ceiling in preventing the progression of the disease? This article reviews successes and late-stage clinical trial disappointments in the treatment of patients with heart failure. Furthermore, the article discusses how agents that have beneficial effects in heart failure also generally attenuate or reverse ventricular remodeling, whereas the newer agents that have failed to improve clinical outcomes either had no effect on remodeling or have been associated with adverse remodeling.

What is the Optimal Angiotensin‐Converting Enzyme Inhibitor Dose in Heart Failure?

Doses of angiotensin-converting enzyme (ACE) inhibitors used in the landmark heart failure trials that demonstrated survival benefit are rarely reached in routine practice. The authors review the current literature regarding optimal dosing of ACE inhibitors in heart failure with specific focus on neurohormonal, functional capacity, and clinical outcomes. Neurohormonal studies have shown that lower ACE inhibitor dosing may provide inadequate suppression of the renin-angiotensin-aldosterone system. Higher doses of ACE inhibitors have resulted in greater increments in exercise and functional capacity. Clinically, patients on high-dose ACE inhibitor therapy had significant reductions in all-cause mortality or hospitalization, cardiovascular hospitalizations, and heart failure-specific hospitalizations. There is, however, conflicting evidence, and so continued uncertainty exists regarding optimal dosing. Despite underutilization of ACE inhibitors, there is insufficient evidence to support lower doses. Likewise, limited data exist for doses higher than those used in the landmark trials. Clinicians should therefore attempt to reach target doses in heart failure whenever possible.

Relationship of dose of background angiotensin-converting enzyme inhibitor to the benefits of candesartan in the Candesartan in Heart failure: Assessment of Reduction in Mortality and morbidity (CHARM)-Added trial

BACKGROUND

Whether an angiotensin receptor blocker is of benefit when added to a full dose of angiotensin-converting enzyme (ACE) inhibitor in heart failure (HF) is uncertain.

METHODS

The effect of candesartan, compared with placebo, in 2548 patients randomized in the CHARM-Added trial was analyzed according to (i) ACE inhibitor dose at baseline, (ii) ACE inhibitor dose during follow-up, and (iii) combination treatment with ACE inhibitor and beta-blocker at baseline. The main outcome was the composite of cardiovascular death or HF hospitalization.

RESULTS

The benefit of candesartan was not modified by the dose of ACE inhibitor. In all patients (n = 2548), the candesartan/placebo hazard ratio (HR) for the primary outcome was 0.85 (95% CI 0.75-0.96). In patients taking a guideline recommended dose of ACE inhibitor at baseline (n = 1291), this HR was 0.79 (95% CI 0.67-0.95; interaction P value .26). In patients taking a Food and Drug Administration-designated maximum dose of ACE inhibitor (n = 529), this HR was 0.75 (95% CI 0.57-0.98; interaction P value .29). The benefit of candesartan was preserved in patients taking beta-blockers in addition to a higher dose of ACE inhibitor and in patients maintaining a high dose of ACE inhibitor throughout follow-up.

CONCLUSIONS

These clinical findings support the pharmacologic evidence that ACE inhibitors and angiotensin receptor blockers have distinct mechanisms of action and show that their combined use improves outcomes in patients with HF more than an evidence-based dose of ACE inhibitor alone.

Prevalence and Prognostic Significance of Anemia in Patients With Congestive Heart Failure Treated With Standard vs High Doses of Enalapril

BACKGROUND

Anemia is common in patients with congestive heart failure (CHF), although its etiology and pathophysiology remain largely unexplained. The purpose of this study was to examine the prognostic significance of a low hematocrit (Hct) in patients with CHF and the possible role of angiotensin-converting enzyme inhibition in anemia development.

METHODS

Hct was measured at the time of enrollment of 160 patients with CHF, mean age 56 +/- 12 years, in New York Heart Association (NYHA) functional class 2.6 +/- 0.7 and with left ventricular ejection fraction of 20 +/- 9%. They were randomized to standard (mean: 17.9 +/- 4.3 mg/day) or high (mean: 42 +/- 19.3 mg/day) doses of enalapril. The follow-up duration was 2 years. Cox regression models were used to identify prognostic factors, and correlations among individual variables were tested.

RESULTS

Mean baseline Hct was 42.7 +/- 5%. In multivariate analyses, low Hct (p = 0.036), older age (p = 0.022) and low systolic blood pressure (p = 0.032) were independent predictors of death within 2 years. A correlation was found between baseline Hct and NYHA class (Spearman's correlation coefficient: -0.183, p = 0.008). A significant decrease in Hct from 43.2 +/- 4.9% at baseline to 40.7 +/- 4.4% at 2 years was observed in the group treated with high doses of enalapril (p < 0.001).

CONCLUSIONS

Low baseline Hct predicted poor 2-year prognosis in patients with CHF. Enalapril administered in high doses increased the incidence of anemia in this population. The underlying pathophysiologic mechanism and effects of maintaining a normal Hct on clinical outcomes remain to be determined.

Out-patient management of chronic heart failure

Chronic heart failure is a clinical syndrome associated with an ominous long-term prognosis and major economic consequences for Western societies. In recent years, considerable progress has been made in the pharmacological management of heart failure, and several treatments have been confirmed to confer survival and symptomatic benefits. However, pharmaceuticals remain underutilised, and the combination of several different drugs present challenges for their optimal prescription, requiring a thorough knowledge of potential side effects and complex interactions. This article reviews in detail the evidence pertaining to the out-patient pharmacological management of chronic heart failure, and offers recommendations on the use of various drugs in complex clinical conditions, or in areas of ongoing controversy.

Consistency of the beneficial effect of metoprolol succinate extended release across a wide range dose of angiotensin-converting enzyme inhibitors and digitalis

BACKGROUND

The effects of beta-blockade with different extent of angiotensin-converting enzyme inhibitors (ACEI) and digitalization are unknown. To assess the effect of metoprolol succinate controlled release/extended release (CR/XL) combined with high versus low doses of ACEI and digitalis, we analyzed data from The Metoprolol CR/XL Randomized Intervention Trial in Chronic Heart Failure (MERIT-HF) in which patients with heart failure and left ventricular ejection fraction < or =40% were randomized to metoprolol CR/XL versus placebo.

METHODS AND RESULTS

Outcome was analyzed separately for those on a low dose (< or =median) of the ACEI or digitalis versus high dose (> median). The mean dose of ACEI in the high-dose group (n = 1457) was 3 times higher than that in the low-dose group (n = 2094). Mortality was reduced to a similar extent in the high- and low-dose ACEI subgroups (RR = .69 versus .64, respectively). Corresponding figures for combined mortality/all hospitalization and for mortality/hospitalization for heart failure were .85 versus .83, and .70 versus .68, respectively. Likewise, reduction in total mortality with metoprolol CR/XL was similar in patients receiving no digitalis (n = 1447; RR = .56), low dose (n = 1122; RR = .71), or high dose (n = 1421; RR = .71).

CONCLUSION

This analysis of MERIT-HF demonstrates consistent and similar improvement in outcome of patients receiving metoprolol CR/XL when combined with either a high or low dose of an ACEI or digitalis, or no digitalis at all. Thus regardless of ACEI and digitalis dose and whether patients are treated with digitalis or not, it is very important to add a beta-blocker to the existing heart failure therapy. beta-blockers should not be withheld until target doses of ACEI have been achieved.

Inhibition of RAAS--when is it too much?

Deactivation of the renin-angiotensin-aldosterone system (RAAS) is clearly beneficial in patients with recent myocardial infarction and chronic heart failure. Most of the experience with deactivation of the RAAS has been collected in placebo-controlled randomized trials of angiotensin- converting enzyme inhibition (ACEI). The hypothesis that angiotensin receptor blockade may be a better approach to deactivate the RAAS has not survived the test of time. Despite the extensive experience with ACEI and aldosterone receptor blockade in patients with recent myocardial infarction and chronic heart failure, several issues remain unanswered. These are addressed in this review.

Use of angiotensin-converting enzyme inhibitor therapy and dose-related outcomes in older adults with new heart failure in the community

OBJECTIVE

To evaluate the dose-related benefit of angiotensin-converting enzyme (ACE) inhibitor therapy among older adults with heart failure and to evaluate whether low-dose ACE inhibitor therapy is better than none.

DESIGN

Observational cohort study.

SETTING

Community-dwelling older adults in Ontario, Canada.

PATIENTS/PARTICIPANTS

We identified 16539 adults 66 years or older who survived 45 days following their first heart failure hospitalization discharge.

MEASUREMENT AND MAIN RESULTS

Multivariate techniques including propensity scores were used to study the association between the dose of ACE inhibitor therapy dispensed and 3 outcomes: survival, survival or heart failure rehospitalization, and survival or all-cause hospitalization at 1 year of follow-up. Logistic regression models explored the association between initial dose dispensed and subsequent dose reduction or drug cessation. Overall, 10793 (65.3%) of patients were dispensed ACE inhibitor therapy, with more than a third (3935; 36.5%) initiated on low-dose therapy. Relative to dispensing of low-dose ACE inhibitor therapy, nonuse was associated with increased mortality (hazard ratio [HR], 1.12; 95% confidence interval [CI], 1.02 to 1.22). Dispensing medium-dose therapy provided a benefit similar to low-dose (HR, 0.94; CI, 0.86 to 1.03) and dispensing of high-dose therapy was associated with improved survival benefit (HR, 0.76; CI, 0.68 to 0.85). Relative to dispensing of low-dose ACE inhibitor therapy, dispensing high-dose conferred a benefit (HR, 0.87; CI, 0.80 to 0.95) on the composite outcome of 1-year mortality or heart failure hospitalization and the composite outcome of 1-year mortality or all-cause hospitalization (HR, 0.87; CI, 0.81 to 0.93). Relative to those dispensed low-dose ACE inhibitor therapy, those initially dispensed high-dose therapy were twice as likely to have their subsequent dose reduced or the therapy discontinued (odds ratio, 2.36; CI, 2.07 to 2.69).

CONCLUSION

Our findings suggest that when possible, older adults should be titrated to the higher doses of ACE inhibitor therapy evaluated in clinical trials. If older adults cannot tolerate higher doses, then low-dose ACE inhibitor therapy is superior to none. High-dose ACE inhibitor therapy is not as well tolerated as lower doses.

Is too much neurohormonal blockade harmful?

A number of neurohormones and cytokines are activated in heart failure and their activity is related to the progression of heart failure. Inhibiting the deleterious effects of the activated sympathetic and the renin-angiotensin-aldosterone systems with b-blockers, angiotensin-converting enzyme inhibitors, and aldosterone blockers has been remarkably successful in improving the survival of patients with heart failure. However, inhibition of the other neurohormones and cytokines has not provided the expected incremental benefit, and in some cases has been deleterious, suggesting a ceiling effect of further neurohormonal blockade. This article reviews some of these studies and analyzes the possible causes of these observations.

High- Versus Low-Dose ACE Inhibitor Therapy in Chronic Heart Failure

OBJECTIVE

To discuss the controversy associated with the optimal dosing of angiotensin-converting enzyme (ACE) inhibitors in the management of patients with systolic heart failure; specifically, to review data related to the use of high-dose ACE inhibitors related to both neurohormonal and clinical outcomes associated with doses similar to, lower than, and higher than those used in the large, randomized clinical trials.

DATA SOURCES

Primary, review, and meta-analysis articles were identified by MEDLINE search (1987–September 2002) and through secondary sources.

STUDY SELECTION AND DATA EXTRACTION

All of the articles identified from the data sources were evaluated, and all information deemed relevant was included in this discussion. All available comparative dose trials, both prospective and retrospective, were evaluated for clinical and neurohormonal outcomes.

DATA SYNTHESIS

The majority of data comparing the effect of high- with low-dose ACE inhibitors on neurohormonal outcomes demonstrate dose-related reduction in various neurohormonal measurements including plasma ACE, aldosterone, atrial natriuretic peptide, B-type natriuretic peptide, and interleukin-6 levels. Clinical endpoints including New York Heart Association class and heart failure—related hospitalizations were reduced by higher doses, but a dose-related survival benefit has not been demonstrated. Differences in duration of therapy and study design may account for variability in neurohormonal and morbidity results among various studies.

CONCLUSIONS

Despite documented underutilization in clinical practice of doses of ACE inhibitors demonstrated in large controlled trials to improve morbidity and mortality, clinicians should attempt to reach these target doses if possible in patients with heart failure. Higher doses may improve surrogate markers for heart failure without impacting survival.

Angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers: what we know and current controversies

A little more than a decade ago, management of heart failure was changed forever when a number of randomized clinical trials confirmed that a class of drugs, angiotensin-converting enzyme (ACE) inhibitors, could improve survival in patients with heart failure. The recognition that blockade of one of the neurohumoral systems activated in heart failure could improve outcomes prompted widespread testing of other neurohumoral blockers, such as beta-adrenergic blocking agents, aldosterone antagonists, and most recently, angiotensin II type 1 receptor blockers (ARBs) for the treatment of heart failure. This article describes what is known about the use of ACE inhibitors and ARBs in the management of heart failure and presents the current controversies surrounding the use of these agents.

How high should an ACE inhibitor or angiotensin receptor blocker be dosed in patients with diabetic nephropathy?

Angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs), two drug classes that effectively block the actions of the renin-angiotensin system (RAS), have unique capabilities as antihypertensive agents. Recent landmark clinical trials have demonstrated their important roles as primary therapy for the prevention of renal disease in diabetes. The optimal dosage of these RAS blockers required to slow the progression of renal disease or impair the development of cardiovascular risk is not known. However, data from many studies strongly support the use of the higher doses of ACE inhibitors or ARBs to reduce proteinuria. All studies of kidney disease progression demonstrate benefit on slowing only when blood pressure is reduced when using higher doses. In order to accrue the optimum benefit from ACE inhibitors and ARBs, the dose-response relationship for diabetic renal disease will have to be determined. The best strategy, ie, supramaximal doses of ACE inhibitors or ARBs or combining them, is still a matter of debate but may be resolved soon by results of ongoing studies.

Heart failure therapy at a crossroad: are there limits to the neurohormonal model?

The advent of neurohormonal blockade in heart failure (HF) has been an overwhelming success, but current evidence points to a ceiling effect as newer neurohormonal targets are exploited in an incremental manner. This has lead us to question whether the neurohormonal model of HF can be sustained by simply stacking multiple neurohormonal or cytokine blockers together as treatment. A unifying theme in some of these disparate trials relates to either a lack of efficacy or, more importantly, adversity resulting in regression of already achieved benefits. It is our contention that the available evidence has uncovered the remarkable complexity of interaction within the context of the neurohormonal construct. As we stand at a crossroad in HF and begin to fervently pursue non-neurohormonal therapeutic targets, we must also direct attention at navigating the multifaceted labyrinth of the neurohormonal model that has led to the current imbroglio.

Can treatment with angiotensin-converting enzyme inhibitors in elderly patients with moderate to severe chronic heart failure be improved by a nurse-monitored structured care program? A randomized controlled trial

OBJECTIVE

The purpose of this study was to examine whether a nurse-monitored structured care program resulted in a more effective use of angiotensin-converting enzyme (ACE) inhibitors in elderly patients compared with standard care in patients with chronic heart failure (CHF).

METHODS

Hospitalized patients were screened to identify individuals with CHF, age more than 65 years, New York Heart Association classification III to IV, and no contraindications to ACE inhibitor treatment. One hundred forty-five patients were randomized to a nurse-monitored structured care program that included uptitration of enalapril to a target dose of 10 mg twice a day or to standard care. Six-month follow-up data were collected.

RESULTS

The mean age of the randomized patients was 81 years. Although the proportion of patients treated with an ACE inhibitor did not differ between structured care (70%) and standard care (64%), the number of patients with the target ACE inhibitor dose was significantly higher in the structured care group (26% versus 11% in the standard care group; P <.018). Treatment had to be discontinued in 26% of the patients because of adverse effects.

CONCLUSION

The patients in this study were older than in previous intervention studies and had considerable comorbidity and reduced tolerance for ACE inhibitors. ACE inhibitor treatment was underused but improved with the structured care program, although achieved treatment levels were below those in the large intervention trials in patients with CHF.

Renin-angiotensin system inhibition: how much is too much of a good thing?

Inhibitors of the renin-angiotensin system (RAS) are valuable therapeutic agents for a wide range of clinical conditions. Increasingly, consideration is being given to the combination of angiotensin-converting enzyme (ACE) inhibitors and angiotensin-II receptor (AR) antagonists to obtain more complete inhibition of the RAS than can be achieved by either agent alone. Beta-blockers also inhibit the RAS by inhibiting renin secretion. Whereas the combination of an ACE inhibitor and AR antagonist represents dual RAS inhibition, the combination of both of these agents with beta-blocker therapy represents triple RAS inhibition. Animal studies indicate that complete blockade of the RAS produces adverse effects. Moreover, post-hoc analysis of the recent Valsartan Heart Failure Trial study suggests that the combination of ACE inhibitor and AR antagonist therapies may have an adverse effect in heart failure when combined with beta-blocker therapy. There is therefore a need for caution in the combination of ACE inhibition and AR antagonism, particularly in patients receiving beta-blockers, until the impact of this strategy is evaluated.

Renin angiotensin aldosterone and adrenergic modulation in chronic heart failure: contemporary concepts

Whereas the earlier conceptual targets of heart failure therapy, such as the cardio-renal and hemodynamic models, all fulfilled the basic needs of symptomatic relief and hemodynamic improvement, only the neurohormonal model has provided an effective target to address symptom relief in concert with survival benefits. Recent data allude to a disease-modifying effect of angiotensin-converting enzyme inhibitors (ACE-Is) in retarding the new development of heart failure in high-risk populations. Angiotensin receptor antagonists (ARBs) have not been demonstrated to be superior to ACE-Is and their value in achieving incremental benefits in addition to ACE-Is is limited to scenarios in which beta-adrenergic receptor blocker therapy is not applicable. Beta-adrenergic receptor blockade in addition to ACE inhibition offers incremental benefits that are achieved early and are beneficial in most stages of severity except in the presence of overt decompensation. Unlike ACE-Is, beta-adrenergic receptor blockers cannot be construed as a class but are heterogeneous in their therapeutic response.

Patterns of ACE inhibitor use in elderly medicaid patients with heart failure

The authors identified 321 elderly Kansas Medicaid patients with congestive heart failure and examined angiotensin-converting enzyme (ACE) inhibitor use. Using retrospective claims data, ACE inhibitor use was quantified and daily doses compared to a target enalapril-equivalent dose of 20 mg. The cohort patients averaged 80 years of age, 84% were female, and 70% resided primarily in a nursing home. Only 37.8% received an ACE inhibitor. Users were younger than nonusers (t=2.00; p=0.046), but there was no gender difference (odds ratio [OR], 1.4; 95% confidence interval [CI], 0.73, 2.6). ACE inhibitor users averaged eight prescriptions annually, providing approximately 257 medication days (70% of the study period). The average enalapril-equivalent daily dose was 10.6 mg, and only 22% received the target dose. Nursing home residents were less likely to receive an ACE inhibitor than ambulatory patients (OR, 0.55; 95% CI, 0.34, 0.89) but equally likely to receive target doses (OR, 1.3; 95% CI, 0.34, 4.9). ACE inhibitor use in the Kansas Medicaid congestive heart failure population is not consistent with practice guidelines, particularly among older and/or nursing home patients.

B-type natriuretic peptide as a marker of the effects of enalapril in patients with heart failure

BACKGROUND

A-Type and B-type natriuretic peptides are cardiac hormones whose circulating levels reflect the severity of heart failure. It is not known how plasma levels of these hormones respond to changes in cardiac function that occur as a result of treatment with angiotensin-converting enzyme (ACE) inhibitors.

METHODS

Enalapril was administered at 5 mg/d for 3 months in 24 patients with chronic heart failure, and for the next 3 months at 15 mg/d in the high-dose group (n = 12) and 5 mg/d in the low-dose group (n = 12). We measured plasma levels of A-type or B-type natriuretic peptides, as well as conventional measures of cardiac function, such as the cardiothoracic ratio, left ventricular end-diastolic volume, and percent fractional shortening.

RESULTS

Mean (+/- SD) plasma levels of both hormones decreased promptly after 2 weeks of therapy (A-type natriuretic peptide: 140 +/- 107 pg/mL to 81 +/- 68 pg/mL, P = 0.01; B-type natriuretic peptide: 305 +/- 278 pg/mL to 190 +/- 178 pg/mL, P = 0.01). These reductions were sustained throughout therapy. In contrast, the cardiothoracic ratio, left ventricular end-diastolic dimension, and percent fractional shortening had not changed significantly after 3 months of treatment, although improvements were seen after 6 months of treatment. After 6 months, plasma levels of both A-type and B-type natriuretic peptides were significantly lower in the high-dose group than in the low-dose group (A-type natriuretic peptide: 48 +/- 25 pg/mL vs. 57 +/- 27 pg/mL, P = 0.01; B-type natriuretic peptide: 78 +/- 58 pg/mL vs. 139 +/- 61 pg/mL, P = 0.005), whereas no significant differences were observed in the other measures of cardiac function.

CONCLUSION

Plasma levels of A-type and B-type natriuretic peptides appear to be more sensitive markers of heart failure than conventional echocardiographic parameters and cardiothoracic ratios. Measurement of these hormones might be useful for monitoring the effects of treatment with ACE inhibitors.

[Prognostic value of cytokines and neurohormones in severe heart failure]

BACKGROUND AND OBJECTIVES

The screening of candidates for heart transplantation continues to present difficulties. High plasma levels of cytokines and neurohormones have been associated with a poor prognosis in heart failure but their usefulness for identifying candidates for heart transplantation is still not established.

METHODS

In 83 patients (59 11 years old), with systolic left ventricular dysfunction and New York Heart Association functional class III-IV, we assessed levels of aldosterone, atrial natriuretic peptide, plasma renin activity, angiotensin II, norepinephrine, endothelin, interleukin-6 and tumor necrosis factor-alpha.

RESULTS

Over the following year, 13 patients died and 26 received heart transplantation. Mean ejection fraction was 23 6%, end-diastolic and end-systolic diameters were 73 10 and 60 10 mm, respectively. Univariate analysis identified the following variables to be associated with poor prognosis: angiotensin II (p = 0.001), norepinephrine (p = 0.003), plasma renin activity (p = 0.02), systolic blood pressure (p = 0.006), end-diastolic diameter (p = 0.02) and end-systolic diameter (p = 0.04). Multivariate regression analysis identified the following variables to be independent predictors of death or need for heart transplantation: a low cardiac index (p = 0.007), plasma angiotensin II (p = 0.001) and pulmonary capillary wedge pressure (p = 0.04) The sensitivity and specificity of angiotensin II for predicting poor outcome was only moderate according to interpretation of the receiver operating curves.

CONCLUSIONS

Although plasma angiotensin II was the best neurohormone for identifying patients with severe heart failure and the worst prognosis, its sensitivity and specificity for predicting death or the need for heart transplantation was limited. The decision to transplant should continue to be based on clinical and hemodynamic parameters.

Chronic dialysis patients have high risk for pulmonary embolism

Pulmonary embolism has been considered uncommon in chronic dialysis patients, but has not been adequately studied in a large population. In the US Renal Data System (USRDS), 76,718 patients presenting with end-stage renal disease (ESRD) between January 1, 1996, and December 31, 1996, were analyzed in an historical cohort study. The outcome was hospitalizations with a primary discharge diagnosis of pulmonary embolism (International Classification of Diseases, Ninth Revision code 415.1x) occurring within 1 year of the first ESRD treatment and excluding those occurring after renal transplantation. For dialysis patients, hospitalization rates for pulmonary embolism were obtained from the hospitalization section of the 1999 USRDS. For the general population, hospitalization rates for pulmonary embolism were obtained from the National Hospital Discharge Survey for 1996. Comorbidities from the Medical Evidence Form (Centers for Medicare and Medicaid Services, previously known as the Health Care Financing Administration; form 2728) were used to generate approximated stratified models of adjusted incidence ratios for pulmonary embolism (comorbidities could not be stratified for the general population). In 1996, the overall incidence rate of pulmonary embolism was 149.90/100,000 dialysis patients compared with 24.62/100,000 persons in the US population, with an age-adjusted incidence ratio of 2.34 in dialysis patients. Younger dialysis patients had the greatest relative risk for pulmonary embolism. The age-adjusted incidence ratio of pulmonary embolism after excluding dialysis patients with known risk factors for pulmonary embolism was 2.11. Ninety-five percent confidence intervals for all age categories in both models were statistically significant. Chronic dialysis patients have high risk for pulmonary embolism, independent of comorbidity.