Beta-blocker target dosing and tolerability in a dedicated Heart Failure Clinic Charlotte Maxeke Johannesburg Academic Hospital
Bolon, Jonathan Graham
BACKGROUND: The benefit of Beta-blockers in chronic heart failure with left ventricular dysfunction is well established. However, actual use in “real world” heart failure patients has been relatively poor. Beta-blockers have generally been underused and under-dosed, largely due to perceptions about intolerability. Ivabradine, a pure heart rate lowering agent has recently been advocated for heart failure patients with elevated heart rates who could not tolerate target doses of beta-blockers. AIMS: The aim of this study was to document beta-blocker target dosing and tolerability in a dedicated heart failure clinic at Charlotte Maxeke Johannesburg Academic Hospital and assess the proportion of patients who may require Ivabradine therapy. METHODS: The records of all patients attending the heart failure clinic between 2000-2014 were reviewed. Demographic, clinical and outcome data was recorded for 500 patients. RESULTS: At their last clinic visit, 489 out of 500 (97.80%) patients were taking a beta-blocker. Patients were stratified into categories according to guideline target doses, with 59.8% (n=299) achieving ‘target dose’, 28.0% (n=140) a ‘moderate’ dose, 5.4% (n=50) receiving ‘low dose’ of beta-blocker and 11 patients (2.2%) no dose. Beta-blocker “intolerant” patients numbered 61(7.6%). Conventional reasons for beta-blocker caution (bronchospasm/breathlessness, syncope, cardiac decompensation, hypotension) were found to be rare. Bradycardia was the commonest cause of inadequate uptitration. Only 53 patients (10.6%) were deemed to be “Ivabradine suitable”. CONCLUSIONS: Beta-blockers are well tolerated with perceptions around intolerability and concerns about safety largely unsupported by our experience. As a consequence, the role for Ivabradine therapy in patients with chronic heart failure is limited. Key words: Beta-blockers, Heart Failure, Ivabradine
A research report submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in partial fulfillment of the requirements for the degree of Master of Medicine in Internal Medicine. Johannesburg, 2017.