The effect of evidence-based medication use on long-term survival in patients hospitalised for heart failure in Western Australia

Abstract

Objectives: To examine trends and predictors of prescription medications on discharge after first (index) hospitalisation for heart failure (HF), and the effect on all-cause mortality of evidence-based therapy.

Design: A retrospective multicentre cohort study, with medical record review.

Setting: Three tertiary-care hospitals in Perth, Western Australia.

Patients: WA Hospital Morbidity Data were used to identify a random sample of 1006 patients with an index admission to hospital for HF between 1996 and 2006.

Main outcome measures: Proportion of patients prescribed evidence-based therapy for HF on discharge from hospital; and 1-year all-cause mortality.

Results: Among 944 patients surviving to hospital discharge, the prescription rate of angiotensin-converting enzyme (ACE) inhibitors/angiotensin receptor blockers (ARBs) (74.3%) and loop diuretics (85.5%) remained high over the study period, whereas that of beta-blockers and spironolactone increased (10.5% to 51.3% and 1.4% to 23.3%, respectively), and digoxin prescription decreased (38.1% to 20.7%). The temporal trends in use of beta-blockers, spironolactone and digoxin were in line with clinical trial evidence. Age > or = 75 years was a significant, negative predictor of beta-blocker and spironolactone prescription. In-hospital echocardiography, performed in 53% of patients, was associated with a significantly greater likelihood of treatment with ACE inhibitors/ARBs, beta-blockers and spironolactone. Both ACE inhibitors/ARBs and beta-blockers prescribed on discharge were associated with a lower adjusted hazard ratio (HR) for mortality at 1-year (HR, 0.71; P = 0.003; and HR, 0.68; P = 0.002, respectively).

Conclusion: ACE inhibitors/ARBs and beta-blockers, prescribed during initial hospitalisation for HF, are associated with improved long-term survival. Therapy became more evidence based over the study period, but echocardiography, an important predictor of evidence-based therapy, was underutilised.