Angiotensin-converting enzyme inhibitors in p heart failure: target dose prescription in elderly patients

SIR—Despite the benefits of therapy with angiotensinconverting enzyme (ACE) inhibitors for patients with heart failure, these agents are prescribed in only 5-10% of documented cases [1]. In younger people, they are frequently prescribed in doses below those used in clinical trials [2]. These trials have generally excluded subjects aged 75 or above, in whom heart failure is most common. However, the benefits for older patients have been illustrated by a 6-month mortality reduction of up to 40% [3]. A retrospective study was carried out comparing the discharge doses of four ACE inhibitor agents prescribed to patients aged 75 or over for heart failure with the maintenance dosage recommended in the British National Formulary [4]. Those receiving total daily doses below the specified target range were deemed to be sub-optimally treated. Patients with documented hypotension or deterioration in renal function considered to result from therapy were excluded. The results of the study are shown in Table 1. prescribed in higher than recommended doses in 13 (11%) cases compared with none for perindopril (P < 0.001). The question of optimal dosage of ACE inhibitors to treat heart failure is unresolved, but the beneficial effects of high-dose therapy are well established. To date, smaller trials have indicated that greater exercise capability [5], symptomatic improvement and survival [6] occur in subjects receiving high-dose rather than low-dose therapy; larger trials are in progress. However, many patients discharged from hospital on ACE inhibitor therapy for heart failure remain on unchanged doses and do not progress to the higher doses required for maintenance [7]. Although the reasons for this have not been defined, possible contributory factors include adverse effects on renal function, hypotension and its sequelae and the complex titration regimes of some agents. For the present, higher-dose maintenance should remain the objective for all patients, particularly older people where the prognosis is worse. These patients, often frail or living alone, present the greatest practical difficulties in establishing optimal ACE inhibitor therapy and the selection of an agent with