E-Science Station

The risk of athersclerotic cardiovascular disease (ASCVD) is increased in patients with peripheral vascular disease (PVD), abdominal aortic aneurysm (AAA), and carotid artery disease (CAD). In Australia, it is recognised that  many of these events are attributable to comorbid hypertension, high cholesterol, and diabetes ; and the  National Vascular Disease Prevention Alliance (NVDPA), recognises the need for all high risk adults to follow the current Dietary Guidelines for Australian Adults, cease smoking, reduce alcohol intake and undertake behavioural changes for better lifestyle practices.   'Best medical therapy' for atherosclerotic vascular disease include modifying risks, use of antiplatelets or anticoagulants, statins and antihypertensives. Guidelines from the European Society for Vascular Surgery (ESVS), the American College of Cardiology/American Heart Association (ACC/AHA), and the NVDPA recommend the use of 'best medical therapy' in patients with AAA and PAD, to reduce the risks of MI, stroke, heart failure and CV death.  Despite the demonstrated benefits of BMT in vascular disease patients, some studies have shown a lack of use of these medications in patient risk management. P oorer CVD related outcomes and increased case-complexity may therefore be linked to suboptimal secondary preventive practices or adherence to ‘best medical therapy’.  We aimed  to (1) report on the use of best medical therapy in PAD, CAD and AAA patients based on referrals to a private vascular clinic in Australia (2) describe cardiovascular risk factors profiles on patients with PAD, AAA and carotid occlusive disease.

This is a cross-sectional study of patients with established PVD, carotid artery and AAA disease seen in the setting of a private specialist clinic between October 2015 to September 2019 (n=1689). These patients were attending the clinic for the first time, referred by their primary healthcare providers for  PAD, AAA and carotid occlusive disease.Information on patient characteristics, presenting complaints, diagnoses, past medical histories and medication use was obtained by means of a questionnaire, filled out by patients during their appointment, and validated by a vascular surgeon through direct question during consult. The diagnosis of PVD, AAA or CAD was ascertained from the referral letter and confirmed on consultation.Patient age was recorded as an absolute number. Smoking history was grouped into never, ex-smoker <10 years, ex-smoker >10 years, current smoker <20 cigarettes/day, current smoker >20 cigarettes/day. Alcohol consumption was grouped into never, occasionally, weekly, few per week and daily. Comorbidities and relevant medical history were grouped into cardiovascular, respiratory, renal, neurological, hematological, gastrointestinal, musculoskeletal, urological, endocrinological and oncological pathologies. Records of medications included antiplatelets, antihypertensives, lipid-lowering agents and glucose-lowering agents. Baseline data are represented as either a number (%) and mean ± SD. Chi-squared tests or One-way ANOVA was used to investigate differences between PVD, CAD and AAA. p<0.05 for two-tailed testing was considered statistically significant. IBM SPSS Statistics (IBM Corp. Released 2017. IBM SPSS Statistics for Windows, Version 25.0 Armonk, NY: IBM Corp.)

A total of 1,689 participants with a primary diagnosis of PVD, CAD and AAA, who attended private outpatient vascular clinics between October 2015 and September 2019, were identified.  Patient characteristics and cardiovascular risk factors are shown in Table 1. The average age of consult for all patients were 73.4 ± 11.5 years, with a greater proportion of males across all disease groups (total 68.7%, PVD 67.6%, CAD 57.4%, AAA 82.9%). Average body mass index (BMI) of all patients was 27.9 ± 6.0 kg/m². Disease sub-groups were different in terms of age, gender, diabetes, smoking, exercise frequency and hyperlipidaemia. Prevalent risk factors are of a history of current or previous smoker (total 75.2%, PVD 74.4%, CAD 68.7%, AAA 83.9%), hypertension (total 75.9%, PVD 75.0%, CAD, 79.4%, AAA 75.5%) and hyperlipidaemia (total 70.5%, PVD 68.1%, CAD 83.8%, AAA 66.1%).  Patient medical comorbidities are presented in Table 2. Patients had a high prevalence of cardiovascular disease, respiratory disease, gastrointestinal and musculoskeletal conditions. With  PVD, CAD and AAA sub-groups having significantly different proportions of CVD, neurological disease, haematological disease  and prostate disease. Patient uptake of guideline-recommended therapies are shown in Table 3 (Total 38.4%, PVD 36.7%, CAD 49.1%, AAA 34.5%) were on BMT. The proportion of patients on antihypertensives (total 69.9%, PVD 70.1%, CAD 71.5%, AAA 68.0%), antithrombotics of either antiplatelets or anticoagulants (total 63.5%, PVD 61.0%, CAD 76.3%, AAA 60.4%) and lipid-lowering agents were similar (total 65.3%, PVD 63.1%, CAD 78.7%, AAA 60.4%).Statistically significant differences in medication uptake between PVD, CAD and AAA were seen in antiplatelets, lipid-lowering agents and diabetic medications (not shown).

In this study, patients referred to the vascular surgery outpatient clinic should have been on life-long 'best medical therapy'. However, there was suboptimal uptake of antithrombotics, antihypertensives and lipid-lowering agents identified. Reasons for deprescribing medications have been attributed to adverse drug reactions, polypharmacy and palliative care strategies. Our current data does not allow for investigation into maintenance and deprescribing practices of guideline-recommended therapies, however future studies intend to address this gap.
Despite readily available current guidelines this study found suboptimal use and prescribing practices of antithrombotic, antihypertensive and lipid-lowering medications in vascular patients with PVD, CAD and AAA, presenting to a specialist vascular practice. Primary healthcare providers should consider the high risk of CVD posed by vascular disease, and carefully weigh out the risk-benefit ratios when deciding against these medications and revisit the use of these medications with their patients at each visit to ensure compliance.