Patients with PAD generally have widespread arterial disease and therefore are at a significantly increased risk of stroke, myocardial infarction, and cardiovascular death (The TASC Working Group 2001
). Coronary artery disease (CAD) is the most common cause of death in patients with PAD and accounts for 40%–60% of deaths. Stroke accounts for 10%–20% of deaths. Only 20% to 30% of patients with PAD die of non-cardiovascular causes (The TASC Working Group 2001
). Patients with PAD have a 6 fold increased risk of cardiovascular disease mortality compared to patients without PAD (Criqui et al 1992
). Therefore, intensive risk reduction therapy is critical in these patients to reduce the adverse cardiovascular outcomes. Risk reduction pharmacotherapy (antiplatelets, statins, and ACE inhibitors) are proven therapy in reducing the risk of cardiovascular mortality and morbidity in PAD patients in large scale randomized clinical trials (Yusuf et al 2000
; Antithrombotic Trialists’ Collaboration 2002
; Heart Protection Collaborative Group 2002
). On the other hand, although there are no randomized clinical trials to prove the role of smoking cessation and blood sugar control in reducing the adverse cardiovascular outcomes in patients with atherosclerosis; large observational studies showed their effect to do so (Lu and Creager 2004
; Stratton et al 2004).
Although there is strong evidence supporting the importance of using risk reduction therapy in patients with PAD, in this study we have shown that despite the majority of surveyed physicians evaluate and counsel patients with PAD for their risk factors, knowledge and action remain suboptimal, and clear gaps have been identified. Majority of surveyed physicians rated their knowledge about risk reduction as average or above average; however, there is deficiency in the knowledge of the recommended target levels of blood pressure and LDL-cholesterol levels. In addition, minority of the participants knew that ACE inhibitor can be used in PAD patients irrespective to the blood pressure status for reducing atherosclerotic complications and cardiovascular death. Furthermore, there was also deficiency in initiating risk reduction therapy especially for ACE inhibitors and anti-smoking therapies. The action gap was most prominent among general internists compared to other specialties.
Our findings could be explained by the absence of national or locally adapted guidelines in managing patients with PAD and the reluctance of physicians to apply CAD guidelines to the PAD patient population even though the risks are similar, if not higher (Criqui et al 1992
). Furthermore, the suboptimal use of ACE inhibitors could be explained by the fact that the evidence supporting the use of ACE inhibitors in patients with PAD to reduce the risk of adverse cardiovascular events is not a level A evidence and also dependent on the presence of symptoms (class IIa recommendation for symptomatic patients with PAD and Class IIb recommendation for asymptomatic patients) (Hirsch et al 2006
Knowledge and action gaps in managing risk factors in patients with PAD also have been shown among physicians in the United Kingdom, the United States and Canada (McDermott et al 2002
; Mukherjee et al 2002
; Cassar et al 2003
; Al Omran et al 2006
). Cassar et al (2003)
showed that over a quarter of the UK vascular surgeons would not screen for diabetes or measure blood pressure in patients with PAD and only 34% of them would treat claudicants if the cholesterol was greater than 5.5 mmol/l. McDeermott et al (2002) showed that only 45.5% of the internal medicine physicians (IMP) prescribe antiplatelets to patients with PAD compared to 52.5% of the vascular surgeons, and only 16.8% of the vascular surgeons knew the large effect of cholesterol lowering on the risk of future cardiovascular events in patients with PAD compared to 43.6% of the IMP. Furthermore, even in cardiologists who were surveyed there was knowledge and action gaps in dealing with atherosclerotic risk. Al-Omran et al (2006)
showed that the utilization of risk reduction pharmacotherapy and the knowledge of the recommended target levels of blood glucose, blood pressure and LDL-cholesterol levels in patients with PAD among Canadian vascular surgeons were suboptimal. Furthermore, Mukherjee et al showed a suboptimal use of lifestyle modifications such as smoking cessation, exercise, weight reduction and diet for lipid control, and the use of evidence-based therapy such as antiplatelets therapy, ACE-inhibitors, beta-blockers, and statins in patients undergoing peripheral vascular interventions for PAD at hospital discharge and at 6 months follow-up (Mukherjee et al 2002
The knowledge and action gaps in managing risk factors in patients with PAD from the previously published studies (McDermott et al 2002
; Cassar et al 2003
; Al Omran et al 2006
) along with our data add support to the available literature documenting inequities in use of risk reduction therapies for patients with PAD in comparison to patients with CAD (Hirsch et al 2004
). Furthermore, this data can be useful in supporting a call to action for PAD management and public awareness (Hirsch et al 2004
In the evaluation of these results, certain limitations merit emphasis. The small number of the participants included in this survey. It is also important to stress that this survey reflects the practice of physicians in a single teaching institute, and may not be generalizable to other hospitals. Also, since the data represent self-reported perceptions of knowledge they may underestimate the true gap. In addition, the survey form did not differentiate between symptomatic and asymptomatic PAD with regard to the use of ACE inhibitors as a risk reduction therapy.
In conclusion, the perceptions towards risk reduction in PAD identify glaring knowledge and action gaps, despite a considerable effort to evaluate and counsel patients for their risk factors. Given the heightened risk of cardiovascular adverse outcomes in patients with PAD, these data have important and immediate implications. If the current practice continues, the observed knowledge and action gaps are expected to persist. These findings may be useful for guiding targeted interventions such as locally adapted clinical practice guidelines in managing patients with PAD, self audit of practice, focused continuing medical education programs, the inclusion of risk reduction pharmacotherapy as a plenary topic at scientific meetings, and other educational outreach programs that aim to bring physicians’ practice into agreement with current guidelines for cardiovascular risk reduction.