Adherence to Treatment Guidelines in Heart Failure Patients in the Top End Region of Northern Territory

Heart failure among Indigenous and non-Indigenous Australians in remote Central Australia

BACKGROUND

There is a paucity of data on the burden of heart failure (HF) in Central Australia, the most populous Indigenous region in the country.

AIMS

To characterize Indigenous and non-Indigenous Australians with HF in Central Australia.

METHODS

Consecutive patients with HF and reduced ejection fraction <50% were included for the period 2019 to 2021. Clinical, echocardiographic and major adverse cardiovascular events (MACE) data were collected.

RESULTS

Four hundred twenty-four patients with HF were included (70% Indigenous, 59% male; follow-up 2.2 ± 0.5 years). Indigenous Australians were younger (53 ± 15 vs 68 ± 13 years, P < 0.001) with higher rates of rheumatic heart disease (18% vs 1%, P < 0.001), diabetes (63% vs 33%, P < 0.001) and severe chronic kidney disease (CKD; 32% vs 7%, P < 0.001). HF was more prevalent among Indigenous (138 [95% confidence interval (CI), 123-155] per 10 000) compared with non-Indigenous Australians (53 [95% CI, 44-63] per 10 000), particularly among younger individuals and females. There were similar HF aetiologies between groups. Guideline-directed medical therapy (GDMT) was suboptimal and similar between the groups: angiotensin-converting enzyme inhibitor/angiotensin receptor blocker (64% vs 67%, P = 0.47) and β-blockers (68% vs 71%, P = 0.47). Indigenous Australians had a significantly higher rate of MACE (54% vs 28%, P < 0.001) and death from any cause (24% vs 13%, P = 0.013).

CONCLUSIONS

HF is more than two times as prevalent among Indigenous Central Australians, particularly among younger individuals and females. Despite similar HF aetiologies and GDMT, MACE and mortality outcomes are higher in Indigenous individuals with HF. These data have implications for efforts to close the Indigenous gap in morbidity and mortality.

Two Decades of Overuse and Underuse of Interventions for Primary and Secondary Prevention of Cardiovascular Diseases: A Systematic Review

Quality use of anti-hypertensive and cholesterol-lowering medications is crucial for successful cardiovascular disease management. This systematic review aimed to estimate levels of over and underuse of services for primary and secondary prevention of cardiovascular diseases from 2000 to 2020: overprescribing/underprescribing, overtesting/undertesting and overutilization/ underutilization of procedures compared to clinical practice guideline recommendations. Thirteen studies from USA, Europe, Asia and Australia were included. Wide practice variation was identified. Six studies reported overuse (eg, perioperative cardiac consultations, anti-hypertensive overprescribing for normotensive or pre-hypertensive people); and ten studies reported underuse (eg, under-prescribing of statins when indicated and under-screening for familial hypercholesterolemia). Lifestyle recommendations for cardiovascular disease prevention were largely underused. In summary, lack of adherence to published guidelines was prevalent over the past 2 decades for both primary and secondary prevention across settings. Further investigation of potentially justifiable deviations from guidelines are warranted to verify the estimates and identify points for intervention.

Mackay Heart Failure Study: Examining the Root Causes, Compliance With Guideline-Based Therapy and Prognosis

INTRODUCTION

Heart failure patients have poor outcomes comparable to some malignancies; however, the modern guideline directed medical therapy (GDMT) has improved its outcomes. The clinical characteristics and prescribers' compliance with GDMT for heart failure patients have not been studied in the Mackay region.

METHODS

A retrospective cohort study of 115 consecutive adult heart failure patients was conducted at our institution.

RESULTS

The study cohort consisted of 80% (n=92) males. Ischaemia was the leading cause accounting for 54% (n=62) of the cohort, followed by idiopathic cardiomyopathy at 32% (n=37). Drug-induced and Takotsubo cardiomyopathies were responsible for 11% and 1% respectively. Two (2) patients (2%) had valvular heart disease. Hypertension was present in 57% while diabetes and atrial fibrillation were present in 32% and 43% of patients. Fifty-nine per cent (59%) had a smoking history. All, except four patients, had reduced left ventricular ejection fraction (LVEF <50%) at diagnosis. Among patients with coronary ischaemia, 37% and 31% were revascularised with percutaneous coronary interventions and bypass graft surgeries, respectively. Renin-angiotensin-aldosterone system inhibitors and beta blockers were prescribed in 94% and 95% of the patients, respectively. Mineralocorticoid inhibitors were used in 25% while ivabradine was given to 8% of patients. Nine per cent (9%) of patients received cardiac resynchronisation therapy. Most patients had improvement in functional class and LVEF during follow-up. There were very few mortalities at 3% (n=3) at the median follow-up of 403 (IQR 239-896) days.

CONCLUSION

Our study has shed light on heart failure epidemiology in the Mackay region. We found excellent compliance with GDMT and good prognosis for most patients in terms of both symptom and survival.

Pharmacology of Ivabradine and the Effect on Chronic Heart Failure

Chronic Heart Failure (CHF) is a complex clinical syndrome with a high incidence worldwide. Although various types of pharmacological and device therapies are available for CHF, the prognosis is not ideal, for which, the control of increased Heart Rate (HR) is critical. Recently, a bradycardic agent, ivabradine, is found to reduce HR by inhibiting the funny current (If). The underlying mechanism states that ivabradine can enter the Hyperpolarization-activated Cyclic Nucleotide-gated (HCN) channels and bind to the intracellular side, subsequently inhibiting the If. This phenomenon can prolong the slow spontaneous phase in the diastolic depolarization, and thus, reduce HR. The clinical trials demonstrated the significant effects of the drug on reducing HR and improving the symptoms of CHF with fewer adverse effects. This review primarily introduces the chemical features and pharmacological characteristics of ivabradine and the mechanism of treating CHF. Also, some expected therapeutic effects on different diseases were also concluded. However, ivabradine, as a typical If channel inhibitor, necessitates additional research to verify its pharmacological functions.