Cost-Effectiveness of New Cardiac and Vascular Rehabilitation Strategies for Patients with Coronary Artery Disease

Objective: Peripheral arterial disease (PAD) often hinders the cardiac rehabilitation program. The aim of this study was evaluating the relative cost-effectiveness of new rehabilitation strategies which include the diagnosis and treatment of PAD in patients with coronary artery disease (CAD) undergoing cardiac rehabilitation. Data Sources: Best-available evidence was retrieved from literature and combined with primary data from 231 patients. Methods: We developed a Markov decision model to compare the following treatment strategies: 1. cardiac rehabilitation only; 2. ankle-brachial index (ABI) if cardiac rehabilitation fails followed by diagnostic work-up and revascularization for PAD if needed; 3. ABI prior to cardiac rehabilitation followed by diagnostic work-up and revascularization for PAD if needed. Quality-adjusted-life years (QALYs), life-time costs (US $), incremental cost-effectiveness ratios (ICER), and gain in net health benefits (NHB) in QALY equivalents were calculated. A threshold willingness-to-pay of$75 000 was used. Results: ABI if cardiac rehabilitation fails was the most favorable strategy with an ICER of $44 251 per QALY gained and an incremental NHB compared to cardiac rehabilitation only of 0.03 QALYs (95$75 000/QALY. After sensitivity analysis, a combined cardiac and vascular rehabilitation program increased the success rate and would dominate the other two strategies with total lifetime costs of $30 246 a quality-adjusted life expectancy of 3.84 years, and an incremental NHB of 0.06 QALYs (95%CI:−0.24, 0.46) compared to current practice. The results were robust for other different input parameters. Conclusion: ABI measurement if cardiac rehabilitation fails followed by a diagnostic work-up and revascularization for PAD if needed are potentially cost-effective compared to cardiac rehabilitation only

Cost, clinical effectiveness, and cost-effectiveness of (new) rehabilitation strategies for patients with coronary artery disease^¶.

<p>QALY = Quality-Adjusted- Life Year; ABI = Ankle Brachial Index; PAD = Peripheral Arterial Disease; WTP = Willingness To Pay; Net health benefit = QALYs – (lifetime costs/ WTP).</p>*<p>Future costs and life years were discounted at 3% per year.</p>†<p>2005 US dollars.</p>‡<p>More expensive and less effective than other strategy.</p>§<p>Compared to the next best strategy.</p>¶<p>Numbers are means (95% confidence intervals) derived from probabilistic sensitivity analysis.</p

Intermediate Outcomes: number of fatal and non-fatal cardiac events^* during follow-up and number of fatal and non-fatal peri-procedural complications in the base-case analysis in a hypothetical cohort of 10 000 patients.

<p>Cardiac event = acute angina or non-fatal myocardial infarction; ABI = Ankle-Brachial index; PAD = Peripheral Arterial Disease.</p>*<p>unrelated to PAD revascularization.</p

Schematic simplified representation of the Markov model.

<p>It shows three different rehabilitation strategies. Every strategy contains health states in which a patient can remain for more than one cycle. The health states are pre-rehabilitation (from which every patient starts), successful rehabilitation, failed rehabilitation, post non-fatal cardiac event, and death (i.e. cardiac death or non-cardiac death). All health states are only demonstrated in the upper strategy for simplification. MI = Myocardial infarction; PAD = peripheral arterial disease; CAD = coronary artery disease; ABI = ankle brachial index.</p

Acceptability curves for new cardiac and vascular rehabilitation strategies for patients with coronary artery disease.

<p>The x axis shows a range of values that society may be willing to pay for health benefits, and the elevation of the curve on the y axis denotes the probability that the strategy has an incremental cost-effectiveness ratio that is more favorable than the corresponding willingness to pay.</p

Data included in the Markov model on rehabilitation strategies for patients with coronary artery disease.

<p>ALGH: Advocate Lutheran General Hospital; PTFE = Poly Tetra Fluor Ethylene, PTA = Percutaneous Transluminal Angioplasty, PAD = Peripheral Arterial Disease.</p>*<p>Systemic complication is defined as all events that occurred within 30 days after the procedure and that required additional medical care.</p>†<p>Patency estimates for iliac PTA with selective stent placement have been shown to equal those for iliac PTA with primary stent placement <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0003883#pone.0003883-Tetteroo1" target="_blank">[29]</a>.</p>‡<p>In the Markov model, we assumed that 5% of the lesions were not suitable for surgery.</p>§<p>numbers are 95% CIs for the beta distributions.</p