Faculty Bibliography

OBJECTIVES: Renal dysfunction is associated with increased risk of cardiovascular disease and is an independent predictor of stroke and systemic embolism. Nonvalvular atrial fibrillation (NVAF) patients with renal dysfunction may face a particularly high risk of thromboembolism and bleeding. The current retrospective cohort study was designed to assess the impact of renal function on ischemic stroke and major bleeding rates in NVAF patients in the real-world setting (outside a clinical trial). METHODS: Medical claims and Electronic Health Records were retrieved retrospectively from Optum's Integrated Claims-Clinical de-identified dataset from May 2011 to August 2014. Patients with NVAF treated with warfarin (2468) or rivaroxaban (1290) were selected. Each treatment cohort was stratified by baseline estimated creatinine clearance (eCrCl) levels. Confounding adjustments were made using inverse probability of treatment weights (IPTWs). Incidence rates and hazard ratios of ischemic stroke and major bleeding events were calculated for both cohorts. RESULTS: Overall, patients treated with rivaroxaban had an ischemic stroke incidence rate of 1.9 per 100 person-years (PY) while patients treated with warfarin had a rate of 4.2 per 100 PY (HR = 0.41 [0.21-0.80], p = .009). Rivaroxaban patients with an eCrCl below 50 mL/min (N = 229) had an ischemic stroke rate of 0.8 per 100 PY, while the rate for the warfarin cohort (N = 647) was 6.0 per 100 PY (HR = 0.09 [0.01-0.72], p = .02). For the other renal function levels (i.e. eCrCl 50-80 and >/=80 mL/min) HRs indicated no statistically significant differences in ischemic stroke risks. Bleeding events did not differ significantly between cohorts stratified by renal function. CONCLUSIONS: Ischemic stroke rates were significantly lower in the overall NVAF population for rivaroxaban vs. warfarin users, including patients with eCrCl below 50 mL/min. For all renal function groups, major bleeding risks were not statistically different between treatment groups.

Objectives: Prevalence of diabetes in peripheral artery disease patients is high and these patients are at increased risk for major cardiovascular events. This study's aim was to use a retrospective cohort to assess healthcare resource use (HRU) and costs among critical limb ischemia (CLI) patients with diabetes. Methods: Using a major US database comprised of integrated administrative claims and electronic health records (2007-15), we estimated annual all-cause HRU and total healthcare costs for a sample of 3,189 CLI adults >= 50 years. CLI was characterized by rest pain, ulceration or gangrene. HRU and costs were calculated from medical and pharmacy claims for 1 year following first diagnosis of CLI (index date). Patients who died in the post-index period were included. We stratified patients into 2 cohorts: with and without pre-index diabetes diagnosis. Reverse Engineering and Forward Simulation (REFSTM), a hypothesis free machine learning platform that uses Bayesian network inference, was used to build an ensemble of prediction models for hospitalization and annual total healthcare costs of CLI patients. Results: Nearly 50% of CLI patients had comorbid diabetes. Diabetics had more hospitalizations (mean [SD]: 1.5 [2.0] vs 1.1 [1.6], p< 0.001) and higher costs ($70,808 [$102,568] vs $43,319 [$76,751], p< 0.001) compared to non-diabetics. REFSTM selected factors with the highest frequency in both models. Those predictive of hospitalization were (OR, SD): cellulitis and abscess (2.1, 0.04), beta blockers non-selective (2.1, 1.3), and other aftercare (1.6, 0.1). Predictors of increased costs were (% change in cost, SD): south region (1.2, 0.03), chronic skin ulcers (2.0, 0.1), and chronic kidney disease (1.9, 0.2). Conclusions: HRU and costs were higher for CLI patients with comorbid diabetes. Factors driving these increases in the overall CLI population may be related to the increased complexity of comorbid diabetes and may provide an opportunity for cost savings via timely care decisions in diabetes and CLI

Type 2 diabetes mellitus (T2D) is a major risk factor for cardiovascular disease (CVD), the most common cause of death in T2D. Yet, <50% of U.S. adults with T2D meet recommended guidelines for CVD prevention. The burden of T2D is increasing: by 2050, approximately 1 in 3 U.S. individuals may have T2D, and patients with T2D will comprise an increasingly large proportion of the CVD population. The authors believe it is imperative that we expand the use of therapies proven to reduce CVD risk in patients with T2D. The authors summarize evidence and guidelines for lifestyle (exercise, nutrition, and weight management) and CVD risk factor (blood pressure, cholesterol and blood lipids, glycemic control, and the use of aspirin) management for the prevention of CVD among patients with T2D. The authors believe appropriate lifestyle and CVD risk factor management has the potential to significantly reduce the burden of CVD among patients with T2D.

Aims: Acute myocardial infarction (AMI) is a significant cardiovascular complication following non-cardiac surgery. We sought to evaluate national trends in perioperative AMI, its management, and outcomes. Methods and results: Patients who underwent non-cardiac surgery from 2005 to 2013 were identified using the United States National Inpatient Sample. Perioperative AMI was evaluated over time. Propensity score matching was used to compile a cohort of AMI patients managed invasively (defined as cardiac catheterization or coronary revascularization) vs. conservatively. The primary outcome was in-hospital all-cause mortality. Among 9 566 277 hospitalizations for major non-cardiac surgery, perioperative AMI occurred in 84 093 (0.88%). Over time, the rate of perioperative AMI per 100 000 surgeries declined by 170 [95% confidence intervals (95% CI) 158-181], from 898 in 2005 to 729 in 2013 (P for trend <0.0001). Perioperative AMI occurred most frequently in patients undergoing vascular (2.0%), transplant (1.6%), and thoracic (1.5%) surgery. In-hospital mortality was higher in patients with perioperative AMI than those without AMI [18.0% vs. 1.5%, P < 0.0001; adjusted odds ratio (OR) 5.76, 95% CI 5.65-5.88]. Mortality associated with perioperative AMI declined over time (adjusted OR 0.86, 95% CI 0.84-0.88). In a propensity-matched cohort of 34 650 patients with perioperative AMI, invasive management was associated with lower mortality than conservative management (8.9% vs. 18.1%, P < 0.001; OR 0.44, 95% CI 0.41-0.47). Conclusion: In an observational cohort study from the USA, perioperative AMI occurs in 0.9% of patients undergoing major non-cardiac surgery and is strongly associated with in-hospital mortality. Invasive management of such patients may mitigate some of this excess risk, and further research on the management of perioperative AMI is warranted.