Dressing heart-failure patients on Savile Row--tailored treatment?

NTproBNP-guided drug treatment for chronic heart failure: design and methods in the “BATTLESCARRED” trial

BACKGROUND

How best to decide when to introduce drugs and what doses are optimal in individual patients with chronic heart failure (CHF), is unclear.

AIMS

We will determine whether titration of drug treatment according to plasma NTproBNP is superior regarding clinical outcomes to intensive standardised clinical assessment; whether either of the regimens noted above is superior to usual care; and whether age alters the relative efficacy of NTproBNP guided treatment.

METHODS

We will randomise 360 patients, stratified by age, to drug treatment directed by plasma NTproBNP, to intensive standardised clinical assessment, or to usual care. The primary outcome is total mortality, and secondary outcomes include death plus hospital admission for any cardiovascular event plus episodes of outpatient decompensated heart failure. Analyses will be conducted at the end of one and two years.

RESULTS

308 patients have been recruited, the majority being in NYHA functional class II, 60.6% being >75 years. The entry plasma NTproBNP level is 238, 50-1250 pmol/l, median and range, approximately 400-11,000 pg/ml.

CONCLUSION

We describe details of a study to test the potential utility of serial measurements of NTproBNP in adjusting the drug treatment of patients with CHF. Projected completion date is 2007.

Comparison of treatment initiation with bisoprolol vs. enalapril in chronic heart failure patients: rationale and design of CIBIS-III

BACKGROUND

Angiotensin-converting-enzyme (ACE) inhibitors and beta-blockers are standard therapy for chronic heart failure (CHF). beta-blockers are recommended to be initiated after ACE-inhibitors, but this order is not evidence based. The initiation order may be important since many, especially elderly CHF patients cannot tolerate target doses of both. Data suggest that beta-blockers may be more important to CHF patients than ACE-inhibitors, especially in early stages of CHF.

AIMS

To compare the effect on combined death or hospitalisation of initial monotherapy with either bisoprolol or enalapril, followed by combination therapy.

METHODS

One-thousand CHF patients without ACE-inhibitor, beta-blocker or angiotensin-receptor-blocker therapy will be randomised 1:1 to monotherapy with either enalapril or bisoprolol for 6 months, followed by combined therapy for 6-18 months. The primary objective is to show non-inferiority for bisoprolol-first vs. enalapril-first regarding combined death or hospitalisation. If that is shown, superiority for bisoprolol-first will be tested.

CONCLUSIONS

If the trial shows non-inferiority for bisoprolol-first vs. enalapril-first, the first CHF therapy may be chosen based on individual judgement in each patient. If bisoprolol-first is superior to enalapril-first, a beta-blocker should be given prior to an ACE-inhibitor in CHF, and the paradigm of testing CHF compounds against a background of ACE-inhibitor therapy will be challenged.

Statistical significance versus clinical relevance in cardiovascular medicine

Evidence-based medicine is the foundation of everyday clinical practices and large clinical trials investigating the effects of various interventions on morbidity and survival and generally provide the most robust evidence. Cardiovascular medicine is considered one of the most evidence-based disciplines of medicine. However, there are a number of limitations to the general applicability of clinical trial results in cardiovascular medicine. Although generally useful to the clinician, clinical trials have often been suboptimally designed from 1 or several points of view. As a consequence of flaws in the design and the execution of the trials, statistical significance is quite often not equal to clinical relevance. This article outlines some of the shortcomings of designing and carrying out clinical trials, as well as inadequacies concerning the publication, interpretation, and implementation of the trial results. Evidence-based medicine is obviously not always as solid as one might think.

Brain natriuretic peptide-guided therapy for heart failure

The drug treatment of heart failure, once simple, has become complex. Apart from a loop diuretic and digoxin, most patients should now be receiving an angiotensin-converting enzyme inhibitor (or angiotensin II receptor blocker), a beta-blocker and spironolactone. Newer drugs, such as endothelin-receptor antagonists and combined blockers of converting-enzyme and neutral endopeptidase, might soon become available. When to introduce these drugs and what dose is optimal for any individual, are questions that currently vex clinicians. We proposed that plasma levels of the cardiac hormone brain natriuretic peptide (BNP, or better, its 1-76 amino-acid N-terminal fragment, N-BNP), would provide an objective index for guiding drug treatment in patients with established, stable cardiac failure. In a pilot study, 69 patients were randomized to drug treatment based on clinical criteria, or based on plasma levels of N-BNP. After a median follow-up of 9.6 months, those in the N-BNP group had fewer clinical end-points than those in the group managed by clinical criteria alone (19 vs 54; P= 0.02). These preliminary data encourage the concept that the increasingly complex pharmacotherapy for heart failure, both chronic (as in this trial) and acute, might best be guided by an objective measure such as plasma levels of BNP or N-BNP.

Are we ready for pharmacogenomics in heart failure?

Heart failure is a major health problem and is associated with a high mortality and morbidity. Recently, the role of the genetic background in the onset and development of the disease has been evidenced in both heart failure with and without systolic dysfunction, and in familial and non-familial forms of this condition. Familial forms of dilated cardiomyopathy are more frequent than previously thought. Various modes of inheritance and phenotypes have been reported and this condition appears genetically highly heterogenous. Five genes (dystrophin, cardiac actin, desmin, lamin A/C and delta-sarcoglycan), and additional loci, have been identified in families in which dilated cardiomyopathy is isolated or associated with other cardiac or non-cardiac symptoms. It has been postulated that the molecular defect involved could lead to abnormal interactions between cytoskeletal proteins, responsible either for defect in force transmission or for membrane disruption. More recently, the identification of mutations in genes encoding sarcomeric proteins has led to a second hypothesis in which the disease might also result from a force generation defect. In non-monogenic dilated cardiomyopathy, susceptibility genes (role in the development of the disease) and modifier genes (role in the evolution/prognosis of the disease) have so far been identified. Some data suggest that the efficacy of angiotensin converting enzyme inhibitors, and side-effects, might be related to some genetic polymorphisms, such as the I/D polymorphism of the angiotensin converting enzyme gene. Although preliminary, these data are promising and might be the first step towards application of phamacogenetics in heart failure. This is of paramount importance as the medical treatment of heart failure is characterized by the need for polypharmacy. One of the major challenges of the next millenium, therefore, will be to identify genetic factors which might help define responders to major treatment classes, including angiotensin converting enzyme inhibitors, beta-adrenoreceptor antagonists, angiotensin AT1 receptor antagonists, spironolactone, vasopeptidase inhibitors and endothelin receptor antagonists.