Efficacy of a guideline-recommended risk-reduction program to improve cardiovascular and limb outcomes in patients with peripheral arterial disease
Hussain MA, Al-Omran M, Mamdani M, Eisenberg N, Premji A, Saldanha L, Wang X, Verma S, Lindsay TF. JAMA Surg. 2016; 151(8):742-50. Epub 2016 Apr 6.
Importance — Patients with peripheral arterial disease (PAD) are at a high risk for cardiovascular events, yet, to our knowledge, no studies have examined the effect of a comprehensive risk-reduction program on long-term outcomes for patients with PAD.
Objective — To investigate whether a program that focuses on 8 major guideline-recommended risk-management therapies reduces cardiovascular and limb events in patients with PAD.
Design, Setting and Participants — An observational cohort study with up to 7 years of follow-up was conducted using data from administrative databases from Ontario, Canada, between July 1, 2004, and March 31, 2013. Patients with symptomatic PAD who were enrolled in the Systematic Assessment of Vascular Risk (SAVR) program at a single tertiary vascular center in Ontario between July 2004 and April 2007 were matched with up to 2 (control) patients with PAD from other Ontario tertiary vascular centers not enrolled in the program using propensity score methods. Cox proportional hazards regression analysis was used to compare outcomes.
Exposures — Program that promoted antiplatelet agents, statins, angiotensin-converting enzyme inhibitors, blood pressure control, lipid control, diabetic glycemic control, smoking cessation, and target body mass index by engaging vascular surgeons, family physicians, and patients with PAD.
Main Outcomes and Measures — The primary outcome was a composite risk ratio of death, acute myocardial infarction, or ischemic stroke. Secondary outcomes included rates of lower limb amputations, bypass surgical procedures, and peripheral angioplasties with and without a stent.
Results — A total of 791 patients were studied after propensity score matching; the mean (SD) age of patients in the SAVR group (n = 290) was 67.9 (10.4) years and 68.2 (11.2) years in the control group (n = 501). During follow-up, the SAVR group experienced the primary outcome at a significantly lower rate than the control group (adjusted hazard ratio [HR], 0.63; 95% CI, 0.52-0.77). Patients in the SAVR group were also less likely to have major amputation (adjusted HR, 0.47; 95% CI, 0.29-0.77), minor amputation (adjusted HR, 0.26; 95% CI, 0.13-0.54), bypass surgery (adjusted HR, 0.47; 95% CI, 0.30-0.73), or hospitalization due to heart failure (adjusted HR, 0.73; 95% CI, 0.53-1.00). The rate of peripheral angioplasty with or without a stent was higher among the SAVR group (adjusted HR, 2.97; 95% CI, 2.15-4.10).
Conclusions and Relevance — A guideline-recommended risk-reduction program targeted at patients with PAD was associated with fewer cardiovascular and limb events over the long-term. This finding emphasizes the need for well-designed prospective studies to develop and examine the effect of such programs on reducing PAD-related morbidity, mortality, and health care costs.