The design and rationale of the saxagliptin assessment of vascular outcomes recorded in patients with diabetes mellitus-thrombolysis in myocardial infarction (SAVOR-TIMI) 53 study.

OBJECTIVES: Saxagliptin, a dipeptidyl peptidase 4 inhibitor, improves glycemic control in patients with type 2 diabetes mellitus (T2DM) by increasing endogenous active, intact glucagon-like peptide 1 and glucose-dependent insulinotropic polypeptide in response to food, which augments insulin secretion and decreases glucagon release. RESEARCH DESIGN AND METHODS: SAVOR-TIMI 53 is a phase 4, randomized, double-blind, placebo-controlled trial conducted in 25 countries that is designed to evaluate the safety and efficacy of saxagliptin during long-term treatment of approximately 16,500 patients with T2DM. Eligible patients who are either treatment naive or on any background antidiabetic treatment (except incretin therapy) with history of established cardiovascular (CV) disease or multiple risk factors are randomized 1:1 to saxagliptin 5 mg QD (2.5 mg in subjects with moderate/severe renal impairment) or matching placebo, stratified by qualifying disease state. The primary end point is the composite of CV death, nonfatal myocardial infarction, or nonfatal ischemic stroke. The trial will continue until approximately 1,040 primary end points accrue, providing 85% power to identify a 17% relative reduction of the primary end point with saxagliptin versus placebo and 98% power to test for noninferiority of saxagliptin versus placebo (reject the upper limit of 95% CI for a hazard ratio <1.3 at a 1-sided α of .025). CONCLUSION: SAVOR-TIMI 53 is testing the hypothesis that treatment with saxagliptin is safe and reduces CV events in high-risk patients with T2DM.

A systematic assessment of cardiovascular outcomes in the saxagliptin drug development program for type 2 diabetes.

OBJECTIVE: The objective was to assess the relative risk (RR) for cardiovascular (CV) events across all 8 randomized phase 2/3 trials evaluating saxagliptin in patients with type 2 diabetes mellitus. METHODS: Cardiovascular events (death, myocardial infarction [MI], stroke, revascularization procedures, and cardiac ischemia) were reported by investigators through standard adverse event reporting procedures and were systematically identified. Post hoc blinded adjudication of all deaths, MIs, and strokes was performed using prespecified endpoint definitions by an independent clinical events committee (CEC). RESULTS: A total of 4607 randomized and treated patients (n = 3356 treated with saxagliptin [2.5-100 mg/d]; n = 1251, comparator [n = 656, placebo; n = 328, metformin; n = 267, uptitrated glyburide]) were included. The median ages were 54 years (saxagliptin) and 55 years (comparator) (interquartile range, 47-61 each); 51% were female, 73% were white, 52% were hypertensive, 44% had hypercholesterolemia, 39% had a smoking history, 20% had a first-degree family member with premature coronary heart disease, and 12% had prior CV disease. Cardiovascular events were experienced by 61 patients (38 [1.1%], saxagliptin; 23 [1.8%], comparator), and CV death/MI/stroke events were reported by investigators in 41 patients: 23 (0.7%), saxagliptin; 18 (1.4%), comparator (relative risk, 95% confidence interval [CI], 0.44 [0.24-0.82]). The CEC reviewed 147 patients with potential CV events and identified a total of 40 patients with CV death/MI/stroke: 22 (0.7%), saxagliptin; 18 (1.4%), comparator (RR, 0.43 [0.23-0.80]). Component proportions for CV death, MI, and stroke were (saxagliptin vs comparator): 7 (0.2%) vs 10 (0.8%), 8 (0.2%) vs 8 (0.6%), and 11 (0.3%) vs 5 (0.4%), respectively. CONCLUSION: No increased risk of CV death/MI/stroke was observed in patients randomly assigned saxagliptin across a broad drug development program. Although this systematic overview has inherent and important limitations, the data support a potential reduction in CV events with saxagliptin. The hypothesis of CV protection with saxagliptin will be tested prospectively in a large randomized clinical outcome trial evaluating saxagliptin compared with standard of care in patients with type 2 diabetes at increased risk for CV events.

A health economic analysis of screening and optimal treatment of nephropathy in patients with type 2 diabetes and hypertension in the USA.

BACKGROUND: Nephropathy is an indicator of end-organ damage and is a strong predictor of an increased risk of cardiovascular disease and death in patients with diabetes. Screening can lead to early identification and treatment, both of which incur costs. However, identification and treatment may slow or prevent progression to a more expensive stage of the disease and thus may save money. We assessed the health economic impact of screening for nephropathy (microalbuminuria and overt nephropathy) followed by optimal renoprotective-based antihypertensive therapy in a US setting. METHODS: A Markov model simulated the lifetime impact of screening with semi-quantitative urine dipsticks in a primary care setting of hypertensive patients with type 2 diabetes and subsequent treatment with irbesartan 300 mg in patients identified as having nephropathy. Progression from no nephropathy to end-stage renal disease (ESRD) was simulated. Probabilities, utilities, medication and ESRD treatment costs came from published sources. Clinical outcomes and direct medical costs were projected. Second order Monte Carlo simulation was used to account for uncertainty in multiple parameters. Annual discount rates of 3% were used where appropriate. RESULTS: Screening, followed by optimized treatment, led to a 44% reduction in the cumulative incidence of ESRD and improvements in non-discounted life expectancy of 0.25 +/- 0.22 years/patient (mean +/- SD). Quality-adjusted life expectancy was improved by 0.18 +/- 0.15 quality-adjusted life years (QALYs)/patient and direct costs increased by $244 +/- 3499/patient. The incremental cost-effectiveness ratio was $20 011 per QALY gained for screening and optimized treatment versus no screening. There was a 77% probability that screening and optimized therapy would be considered cost effective with a willingness to pay a threshold of $50 000. CONCLUSION: In patients with type 2 diabetes and hypertension, screening for nephropathy and treatment with a renoprotective-based antihypertensive agent was projected to improve patient outcomes and represent excellent value in a US setting.

Cost-effectiveness of irbesartan 300 mg given early versus late in patients with hypertension and a history of type 2 diabetes and renal disease: a Canadian perspective.

BACKGROUND: The Irbesartan in Reduction of Microalbuminuria trial and the Irbesartan in Diabetic Nephropathy Trial found that irbesartan is renoprotective in patients having hypertension with type 2 diabetes. OBJECTIVE: The objective of this study was to assess whether treatment with irbesartan is cost-effective in Canada relative to conventional care in this patient population and whether it is more cost-effective to treat patients early rather than later in the development of renal disease from the perspective of the Canadian health and social care system. METHODS: The analysis compared 3 alternative strategies for the management of hypertension in patients with type 2 diabetes and early renal disease: (1) conventional hypertensive treatment excluding the use of angiotensin II receptor antagonists (AIIRAs); (2) the early addition of irbesartan (an AIIRA) to conventional treatment; and (3) the late addition of irbesartan to conventional treatment. A Markov model was used to simulate the progression of renal disease (microalbuminuria to death) in hypertensive patients with type 2 diabetes over a 25-year time horizon. Transition probabilities were derived from the 2 randomized controlled trials. A cost-effectiveness analysis was conducted with outcome measured in life-years gained (LYGs). RESULTS: The early addition of irbesartan during microalbuminuria was cost-saving and more effective than both delaying irbesartan treatment until advanced overt nephropathy (AON) (0.45 LYG, Can $54,100 saved) and conventional antihypertensive use (0.62 LYG, $68,400 saved). This was due to the increased drug costs associated with the use of irbesartan being offset by savings arising from delays in the development of overt nephropathy and the subsequent delay to end-stage renal disease (ESRD). Sensitivity analyses confirmed the robustness of the study results. CONCLUSIONS: The early use of irbesartan for patients with hypertension and type 2 diabetes who have yet to develop overt nephropathy is both more effective and less costly than delaying irbesartan treatment until AON and conventional antihypertensive use. Analysis suggests that the earlier irbesartan is added to conventional antihypertensive treatment, the greater the delays in the onset of ESRD and the overall savings in health care resource utilization from the perspective of the Canadian health and social care system.

A French cost-consequence analysis of the renoprotective benefits of irbesartan in patients with type 2 diabetes and hypertension.

OBJECTIVES: We performed a cost-consequence analysis in a French setting of the renoprotective benefit of irbesartan in hypertensive type 2 diabetes patients over a 25-year period. RESEARCH DESIGN AND METHODS: A previously published Markov model simulated progression from microalbuminuria to overt nephropathy, doubling of serum creatinine, end-stage renal disease and death. Three treatment strategies with analogous blood pressure control were compared: (A) control--conventionally medicated antihypertensive therapy (excluding angiotensin converting enzyme inhibitors, other angiotensin-2-receptor antagonists and dihydropyridine calcium channel blockers) initiated at microalbuminuria; (B) early irbesartan--(300 mg daily added to control, initiated with microalbuminuria) and (C) late irbesartan--(300 mg daily, initiated with overt nephropathy). Probabilities came from the Irbesartan in Reduction of Microalbuminuria-2 study, Irbesartan in Diabetic Nephropathy Trial and other sources. Clinical and economic outcomes were projected over 25 years. Annual discount rates were 3%. RESULTS: Compared to control, early use of irbesartan added (mean +/- standard deviation) 1.51 +/- 0.08 undiscounted life years (discounted: 0.94 +/- 0.05 years), while late irbesartan added 0.07 +/- 0.01 (0.04 +/- 0.01) years/patient. Early irbesartan added 1.03 +/- 0.06 discounted quality-adjusted life years (QALYs), while late irbesartan added 0.06 +/- 0.01 QALYs. Early and late irbesartan treatments were projected to save 22,314 +/- 1273 euro and 6619 +/- 820 euro/patient, respectively versus control. Sensitivity analysis showed that even over short time horizons both irbesartan treatments were superior to the control group. CONCLUSIONS: In France, early irbesartan treatment improved quality and length of life and reduced costs in hypertensive patients with type 2 diabetes and microalbuminuria. Late irbesartan therapy is beneficial, but earlier irbesartan leads to better outcomes.

Long-term cost-effectiveness of early and sustained clopidogrel therapy for up to 1 year in patients undergoing percutaneous coronary intervention after presenting with acute coronary syndromes without ST-segment elevation.

BACKGROUND: The superiority of clopidogrel and aspirin versus aspirin alone for up to 1 year in patients who undergo percutaneous coronary intervention (PCI) after presenting with acute coronary syndromes without ST-segment elevation was demonstrated in the PCI-CURE study. We evaluated the long-term cost-effectiveness of clopidogrel use for up to 1 year using patient-level outcomes and resource use from PCI-CURE, and estimates of life expectancy gains based on external sources. METHODS: PCI-CURE involved 2658 patients who underwent PCI between 1998 and 2000 after being randomized in the CURE trial to clopidogrel (n = 1313) or placebo (n = 1345). Roughly two thirds (clopidogrel n = 821, placebo n = 909) underwent PCI during the initial hospitalization (early PCI). Costs were applied to hospitalizations according to diagnosis-related group. Clopidogrel was assigned the average wholesale price of 3.22 dollars per day. Life expectancy gains resulting from the prevention of major clinical events were estimated using external sources. RESULTS: Average total costs were higher with clopidogrel (difference [based on costing method] 253 dollars-423 dollars). For patients who underwent PCI during the initial hospitalization, the difference ranged from 155 dollars lower to 90 dollars higher with clopidogrel. The estimated life expectancy gain with clopidogrel was 0.0885 years, whereas it was 0.0962 years for the early PCI subgroup. Incremental cost per year of life gained with clopidogrel ranges from 2856 dollars to 4775 dollars overall and from dominant (life expectancy benefit with cost savings) to 935 dollars for the early PCI subgroup. CONCLUSIONS: Clopidogrel given for up to 1 year in patients undergoing PCI after presentation with acute coronary syndromes is a highly cost-effective treatment strategy.

Long-term cost effectiveness of early and sustained dual oral antiplatelet therapy with clopidogrel given for up to one year after percutaneous coronary intervention results: from the Clopidogrel for the Reduction of Events During Observation (CREDO) trial.

OBJECTIVES: This study sought to evaluate the long-term cost effectiveness of a clopidogrel loading strategy before percutaneous coronary intervention (PCI) followed by continued treatment for one year. BACKGROUND: The Clopidogrel for the Reduction of Events During Observation (CREDO) trial, a randomized trial of 2,116 patients, showed the effectiveness of antiplatelet therapy with clopidogrel 300 mg before PCI and 75 mg daily for one year afterward compared with placebo load and placebo days 29 to 365 in reducing the combined risk of death, myocardial infarction, and stroke. All patients received clopidogrel on days 1 to 28 and aspirin on days 1 to 365. METHODS: All hospitalizations were assigned a diagnosis-related group. Associated costs were estimated three ways (including professional costs): 1) Medicare costs, 2) MEDSTAT costs, and 3) blend with Medicare for those age > or = 65 years and MEDSTAT for those age <65 years. Clopidogrel 75 mg cost 3.22 dollars. Life expectancy in trial survivors was estimated using external data. Confidence intervals were assessed by bootstrap. RESULTS: The primary composite end point occurred in 89 (8.45%) clopidogrel patients and in 122 (11.48%) placebo patients (relative risk reduction [RRR] 26.9%; 95% confidence interval [CI] 3.9% to 44.4%). The number of life-years gained (LYG) with clopidogrel was 0.1526 (95% CI 0.0263 to 0.2838) using Framingham data and 0.1920 (95% CI 0.054 to 0.337) using Saskatchewan data. Average total costs were 664 dollars higher for the clopidogrel arm (95% CI -461 dollars to 1,784 dollars). The incremental cost-effectiveness ratios (ICERs) based on Framingham data ranged from 3,685 dollars/LYG to 4,353 dollars/LYG, with over 97% of bootstrap-derived ICER estimates below 50,000 dollars/LYG. The ICERs based on Saskatchewan data were 2,929 dollars/LYG to 3,460 dollars/LYG, with over 98% of estimates below 50,000 dollars/LYG. CONCLUSIONS: Platelet inhibition with clopidogrel loading before PCI followed by therapy for one year is highly cost effective.

Irbesartan is projected to be cost and life saving in a Spanish setting for treatment of patients with type 2 diabetes, hypertension, and microalbuminuria.

OBJECTIVES: The purpose of this study was to project the cumulative incidence of end-stage renal disease (ESRD), life expectancy, and costs in a Spanish setting of treating patients with diabetes, hypertension, and microalbuminuria with either standard hypertension treatment alone or standard hypertension treatment plus irbesartan 300 mg daily. METHODS: A peer-reviewed, published Markov model that simulated progression from microalbuminuria to nephropathy, doubling of serum creatinine, ESRD, and all-cause mortality in patients with hypertension, type 2 diabetes, and microalbuminuria was adapted to a Spanish setting. Two strategies were compared: (1) irbesartan versus (2) standard hypertension care with comparable blood pressure control; both began in diabetic hypertensive subjects with microalbuminuria. Cumulative incidence of ESRD, costs, and life expectancy were projected for a hypothetical cohort of 1000 subjects. Future costs and life expectancy were discounted at 3% yearly. A 25-year time horizon and third party payer perspective were used. RESULTS: When compared to standard blood pressure control, irbesartan was projected to reduce the cumulative incidence of ESRD from (mean +/- standard deviation) 24 +/- 1% to 9 +/- 2%, save 11,082 +/- 2,996 euro, and add 1.40 +/- 0.27 life years per treated patient. The superiority of irbesartan over standard care was robust under a wide range of plausible assumptions. CONCLUSION: Treating patients with hypertension, microalbuminuria, and type 2 diabetes with irbesartan was projected to reduce the incidence of ESRD, extend life, and reduce costs.

Cost-effectiveness of early irbesartan treatment versus control (standard antihypertensive medications excluding ACE inhibitors, other angiotensin-2 receptor antagonists, and dihydropyridine calcium channel blockers) or late irbesartan treatment in patients with type 2 diabetes, hypertension, and renal disease.

OBJECTIVE: The aim of this study was to determine the most cost-effective time point for initiation of irbesartan treatment in hypertensive patients with type 2 diabetes and renal disease. RESEARCH DESIGN AND METHODS: This study was a Markov model-simulated progression from microalbuminuria to overt nephropathy, doubling of serum creatinine, end-stage renal disease, and death in hypertensive patients with type 2 diabetes. Two irbesartan strategies were created: early irbesartan 300 mg daily (initiated with microalbuminuria) and late irbesartan (initiated with overt nephropathy). These strategies were compared with control, which consisted of antihypertensive therapy with standard medications (excluding ACE inhibitors, other angiotensin-2 receptor antagonists, and dihydropyridine calcium channel blockers) with comparable blood pressure control, initiated at microalbuminuria. Transition probabilities were taken from the Irbesartan in Reduction of Microalbuminuria-2 study, Irbesartan in Diabetic Nephropathy Trial, and other published sources. Costs and life expectancy, discounted at 3% yearly, were projected over 25 years for 1,000 simulated patients using a third-party payer perspective in a U.S. setting. RESULTS: Compared with control, early and late irbesartan treatment in 1,000 patients were projected to save (mean +/- SD) 11.9 +/- 3.3 million dollars and 3.3 +/- 2.7 million dollars, respectively. Early use of irbesartan added 1,550 +/- 270 undiscounted life-years (discounted 960 +/- 180), whereas late irbesartan added 71 +/- 40 life-years (discounted 48 +/- 27) in 1,000 patients. Early irbesartan treatment was superior under a wide-range of plausible assumptions. CONCLUSIONS: Early irbesartan treatment was projected to improve life expectancy and reduce costs in hypertensive patients with type 2 diabetes and microalbuminuria. Later use of irbesartan in overt nephropathy is also superior to standard care, but irbesartan should be started earlier and continued long term.

Cost of Heart Failure in Patients Receiving beta-Blockers and Angiotensin-Converting Enzyme Inhibitors.

OBJECTIVE: Numerous studies support the benefit of beta-blockers and angiotensin-converting enzyme inhibition (ACE-I) in the management of heart failure. However, the real-world cost of heart failure in patients who take these medications is not well documented; furthermore, it is unclear if heart failure costs remain significant when current, appropriately aggressive care is delivered. DESIGN: This study describes 1-year medical costs in patients hospitalised for heart failure who received these therapies, alone or in combination. METHODS: The study population was derived from 2.5 million patients with at least 3 years' continuous eligibility in Pharmetrics((R)), an integrated claims and pharmacy database on approximately 25 million covered lives from 40 US health plans. The enrolment period was from 1 January 1996 to 31 December 2000. Costs included all recorded payments over a 1-year period. A total of 3073 patients (age >18 years) hospitalised with heart failure were identified (mean [+/- SD] age 72 +/- 13 years; 46% female). RESULTS: The 1-year cost was $US16 786 in patients who received neither ACE inhibitors nor beta-blockers as compared with $US19 567, $US22 785 and $US27 078 in patients who received ACE inhibitors, beta-blockers or both drugs at maximum dosage, respectively (p < 0.001) [year of costing 2000]. Follow-up costs were substantial, representing almost twice the initial hospitalisation cost. Adjusted for age, sex, diabetes mellitus, coronary disease, hypertension and renal failure, costs remained significant in heart failure patients who received ACE inhibitors and/or beta-blockers. CONCLUSIONS: The 1-year cost of therapy for patients with heart failure is substantial, and there remains considerable need for more effective therapy to reduce the societal economic burden.

Blood pressure lowering and life expectancy based on a Markov model of cardiovascular events.

The life expectancy benefits of antihypertensive treatment, based on both systolic and diastolic blood pressure reduction, was estimated with a cardiovascular disease event Markov model with prospective data from 57 573 men and women. Seven patient states were defined, including (1) no cardiovascular disease, (2) stroke, (3) myocardial infarction, (4) revascularization, (5) history of cardiovascular disease, (6) noncardiovascular disease death, and (7) cardiovascular death. Risk functions were developed from gender-specific multivariate Cox proportional hazards models for primary events and age-, smoking-, and diabetes-adjusted models for secondary events. At baseline we assumed (1) hypothetical pretreatment blood pressures of 160/95 or 150/90 mm Hg; (2) strategies A and B lower blood pressure by 20/13 and 13/8 mm Hg, respectively; and (3) baseline age of 35 years. For subjects initially at 160/95 mm Hg, those with antihypertensive treatment, antihypertensive treatment and diabetes, or antihypertensive treatment, diabetes, and currently smoking had corresponding gains in life expectancy of 2.43, 2.80, and 2.43 years for Strategy A. An initial blood pressure of 150/90 mm Hg resulted in similar gains. Compared with Strategy B, with blood pressure reductions of 13/8 mm Hg, Strategy A provided additional gains in life expectancy of 0.84, 0.99, and 0.87 years for those with antihypertensive treatment, antihypertensive treatment and diabetes, or antihypertensive treatment, diabetes, and currently smoking. The initial blood pressure level did not affect the magnitude of life expectancy gains for equivalent blood pressure reductions. Greater gains in life expectancy among hypertensive and diabetic women suggest that blood pressure lowering may yield greater benefits in selected subgroups.

Patient knowledge and awareness of hypertension is suboptimal: results from a large health maintenance organization.

Patient knowledge and awareness of hypertension are important factors in achieving blood pressure control. To examine hypertensive patients' knowledge of their condition, the authors randomly surveyed 2500 hypertension patients from a large health maintenance organization; questionnaires were supplemented with clinic blood pressure measurements. Approximately 72% of the subjects completed surveys. Of patients with uncontrolled hypertension (systolic blood pressure [SBP] > or =140 mm Hg and/or diastolic blood pressure [DBP] > or =90 mm Hg), only 20.2% labeled their blood pressure as "high" and 38.4% as "borderline high". Forty percent of respondents couldn't recall their most recent clinic-based SBP and DBP values. Overall, 71.7% and 61% were unable to report a target SBP or DBP, respectively, or identify elevated targets based on the sixth report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC VI) criteria. Most patients perceived DBP to be a more important risk factor than SBP. Hypertensive patients awareness of blood pressure targets and current hypertension control status, particularly with respect to SBP, is suboptimal. The authors' findings support the need to improve patient education for better management of hypertension.

The cost-effectiveness of irbesartan in the treatment of hypertensive patients with type 2 diabetic nephropathy.

BACKGROUND: End-stage renal disease (ESRD)-related health care costs are substantial. Improving clinical outcomes in patients at risk of progression to ESRD could lead to considerable health care savings. OBJECTIVE: We estimated the cost-effectiveness of irbesartan compared with placebo or amlodipine in the treatment of patients with type 2 diabetes mellitus, hypertension, and overt nephropathy. METHODS: Three treatments for hypertension patients with type 2 diabetes mellitus and nephropathy were assessed: (1) irbesartan, (2) amlodipine, and (3) placebo. A Markov model was developed based on primary data from the Irbesartan in Diabetic Nephropathy Trial and the United States Renal Data System. Projected survival and costs were compared for each treatment at 3-, 10-, and 25-year time horizons. Different assumptions of treatment benefits and costs were tested with use of sensitivity analyses. RESULTS: At 10 and 25 years, the model projected irbesartan to be both the least costly and most effective (ie, demonstrating a survival advantage) strategy. At 25