Congestive Heart Failure
Due to Systolic Dysfunction

• Pharmacologic Therapy
• Beta-blockers-in heart failure
• ACE-inhibitors- use maximal dosages in heart failure
• Angiotensin blockers- instead of and as well as ace-inhibitor therapy with beta-blockers
• Spirinolactone in heart failure
• Nitrate and hydralazine combination for African-Americans

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• Prophylactic ICD therapy

Beta-blockers in heart failure

With increased experience with use of these drugs, I have reached the conclusion that it is appropriate for General Practitioners to use betablockers in this patient group- often beta-blocker therapy is commenced after specialist review, and subsequent dose adjustments can be made by General Practitioners in tandem with the cardiology clinic.

At initial assessment, the patient should be evaluated fully and the diagnosis established. This will usually involve specialist assessment. Usually, one will want to ensure the patient is on ace-inhibitor therapy and progressively increase the dosage of this medication before introducing beta-blocker therapy.

The patient has to be evaluated to ensure there is no need to increase the dose of diuretic therapy. Not infrequently, clinical assessment for pulmonary congestion is misleading. I think it is very useful to obtain a chest X-ray to document clear lung fields before using a betablocker.

In those with a clear chest X-ray, one might even consider the possibility that the patient is on too much diuretic therapy. Clinical assessment and results of serial laboratory measurements of serum urea and creatinine can be helpful.

After these adjustments have been made, the patient's heart rate at rest, blood pressure, and weight should be documented.

Low dose betablocker is introduced (unless contraindications exist). Metoprolol CR 23.75mg or carvedilol 6.25 bd may be prescribed. The target dose of carvedilol is 25mg bd. The highest possible dose of metoprolol should be used. Many have a preference to use carvedilol, but I would not routinely change a patient to carvedilol if they are already treated with metoprolol

I would wait 3-4 weeks in most patients before making the next dose adjustment. Dose increments should be small. Patients should be advised to report any symptoms of worsening heart failure (increased breathlessness, nocturnal dyspnoea, ankle swelling or weight gain). It should be emphasised to the patient to report back early if there is any evidence for worsening heart failure.

Whether the dose can be increased will also be influenced by the resting heart rate and blood pressure. If the patient develops worsening heart failure, then the regular dose of diuretic therapy may be increased and beta-blocker therapy continued.

Greater caution is required in those patients with systolic pressures just over 90mmHg, but even in these patients, often one is able to progressively increase the dose of beta-blocker therapy provided the dose increments are small and changes made after a few weeks. The serum electrolytes and creatinine should be monitored to ensure there is no deterioration of renal function.

Note. The COMET trial results suggest that carvedilol is a better therapy than metoprolol. However, some experts remain concerned about the formulation and dosage of metoprolol used in this trial and these experts believe there may still be no difference between the betablockers. The COMET trial used metoprolol tartrate whereas the MERIT-HF study had used the controlled release formulation of metoprolol succinate (as available in betaloc CR tablets).