Similar risk for ASCVD in PAD patients compared to those with CHD or cerebrovascular disease
Artherosclerotic Risk and Statin Use Among Patients With Peripheral Artery Disease
Introduction and methods
Peripheral artery disease (PAD) is associated with increased risk for atherosclerotic cardiovascular disease (ASCVD) events [1-3]. However, the ASCVD event rates might be underestimated since PAD patients might have more extensive atherosclerosis compared with patients suffering from coronary heart disease (CHD) or cerebrovascular disease and PAD events were not included as outcomes in many studies [3,4]. In addition, previous studies did not include presence of atherosclerosis in multiple vascular beds (e.g. legs, heart and brain) and atherosclerosis in multiple beds is associated with higher increase in future ASCVD events [5-9]. Patients with PAD are advised to use statin medication to reduce the incidence of ASCVD events, but prior studies have suggested that there is an underuse of lipid-lowering medication in PAD patients [1, 12, 13].
The present study provides an assessment of ASCVD event rates and the use of statins in patients with PAD versus patients with CHD and cerebrovascular disease. A retrospective cohort of 943,232 patients with commercial or Medicare health insurance from 2006 to 2017 was used. Lastly, only patients who had at least 1 day of follow-up for ASCVD events and were diagnosed with PAD (i.e., a prior diagnosis of PAD or lower extremity artery revascularization), CHD (i.e., a prior diagnosis of myocardial infarction or CHD, or coronary revascularization), and/or cerebrovascular disease (i.e., a prior diagnosis of stroke, or revascularization of arteries in the neck or head) were included. Primary outcome was a composite of CHD, cerebrovascular disease and PAD events. The cohort was categorized into 7 groups: 1) CHD only; 2) cerebrovascular disease only; 3) PAD only; 4) CHD and cerebrovascular disease, but not PAD; 5) PAD and CHD, but not cerebrovascular disease; 6) cerebrovascular disease and PAD, but not CHD; and 7) CHD, cerebrovascular disease, and PAD. Median follow-up was 3.0 years (25th, 75th percentiles: 1.3, 3.0 years).
- The multivariable-adjusted HRs for ASCVD events associated with 2 and 3 vascular conditions versus 1 vascular condition were 1.45 (95% CI: 1.42 to 1.48) and 2.08 (95% CI: 2.03 to 2.14), respectively.
- The age-standardized ASCVD event rate per 1000 person-years among patients with PAD, CHD, and cerebrovascular disease was 34.7 (95% CI: 33.2 to 36.2), 42.2 (95% CI: 41.5 to 42.8), and 38.9 (95% CI: 37.6 to 40.1), respectively. HRs for ASCVD event were 1.08 (95%CI: 1.04-1.12) in patients with cerebrovascular disease only and 1.02 (95%CI: 0.96-1.09) in patients with PAD with cerebrovascular disease (compared to those with CHD only).
- Among patients with PAD and CHD, with PAD and cerebrovascular disease, and with CHD and cerebrovascular disease, the ASCVD event rate was 72.8 (95% CI: 71.0 to 74.7), 63.9 (95% CI: 60.6 to 67.4), and 67.9 (95% CI: 66.4 to 69.3), respectively. HRs for ASCVD events were 0.94 (95%CI: 0.91-0.97) in patients with PAD and CHD and 0.91 (95%CI: 0.86-0.95) in patients with PAD only (compared to those with CHD and cerebrovascular disease).
- Statin use was lower in patients with PAD only (33.9%) versus those with cerebrovascular disease only (43.0%) or CHD only (51.7%). Statin use was higher in patients with polyvascular disease: CHD and cerebrovascular disease (55.9%); PAD and CHD (50.2%); and PAD, CHD, and cerebrovascular disease (56.5%). Of patients on statin therapy, those with PAD (15.6%) or cerebrovascular disease (19.5%), alone or together (20.1%), less often took high-intensity statin compared to patients with CHD (31.1%).
PAD patients have a similar risk for ASCVD compared to patients with CHD or cerebrovascular disease. Despite this high ASCVD risk however, use of statin treatment was lower compared to counterparts with coronary or cerebrovascular atherosclerosis.