Cost-effectiveness of cardiac resynchronization therapy in the MADIT-CRT trial

Abstract

Background: The Multicenter Automatic Defibrillator Implantation Trial-Cardiac Resynchronization Therapy (MADIT-CRT) trial demonstrated that cardiac resynchronization therapy (CRT) when added to the implantable cardiac defibrillator (ICD) reduces risk of heart failure or death in minimally symptomatic patients with reduced cardiac ejection fraction and wide QRS complex.

Objectives: To evaluate 4-year cost-effectiveness of CRT-ICD compared to ICD alone using MADIT-CRT data.

Research design: Patients enrolled in the trial were randomized to implantation of either ICD or CRT-ICD in a 2:3 ratio, with up to 4-year follow-up period. Cost-effectiveness analyses were conducted, and sensitivity analyses by age, gender, and left bundle branch block (LBBB) conduction pattern were performed.

Subjects: A total of 1,271 patients with ICD or CRT-ICD (US centers only) who reported healthcare utilization and health-related quality of life data.

Measures: We used the EQ-5D (US weights) to assess patient HRQOL and translated utilization data to costs using national Medicare reimbursement rates.

Results: Average 4-year healthcare expenditures in CRT-ICD patients were higher than costs of ICD patients ($62,600 vs 57,050, P = 0.015), mainly due to the device and implant-related costs. The incremental cost-effectiveness ratio of CRT-ICD compared to ICD was $58,330/quality-adjusted life years (QALY) saved. The cost effectiveness improved with longer time horizon and for the LBBB subgroup ($7,320/QALY), with no cost-effectiveness benefit being evident in the non-LBBB group.

Conclusions: In minimally symptomatic patients with low ejection fraction and LBBB, CRT-ICD is cost effective within 4-year horizon when compared to ICD-only.

Figure 1. Accumulated costs, lifetimes, quality-adjusted life years (QALY) and resulting incremental cost-effectiveness ratios (iCERs), unrestricted by heart failure events, for left bundle branch block (LBBB) patients, by active device and by years

All costs and (quality-adjusted) lifetimes are discounted at 3% per annum and are estimated out to a limited time horizon, in years; here, they are unrestricted by occurrence of heart failure events. Extrapolation beyond 4 years would require many additional assumptions and is not attempted. The bars indicate 95% confidence limits for the estimates. Since there is no significant gain in years of life at year 1, the upper limit for year-based iCER goes to infinity; the upper limit for QALY-based iCER at year 1 is 4626. Due to no significantly higher costs in the CRT-ICD group at years 3 and 4, the lower confidence limits of iCER are negative (and not displayed). Numerical values for year 4 appear in Table 3.

Figure 2. Accumulated costs, lifetimes, quality-adjusted life years (QALY) and resulting incremental cost-effectiveness ratios (iCERs), limited to heart failure-free years, for left bundle branch block (LBBB) patients, by active device and by years

All costs and (quality-adjusted) lifetimes are discounted at 3% per annum and are estimated out to a limited time horizon, in years; here, lifetimes (but not costs) are restricted by occurrence of heart failure events, that is, heart failure-free years. Extrapolation beyond 4 years would require many additional assumptions and is not attempted. The bars indicate 95% confidence limits for the estimates. Due to no significantly higher costs in the CRT-ICD group at years 3 and 4, the lower confidence limits of iCER are negative (and not displayed). Numerical values for year 4 appear in Table 3.

Figure 3. Cost-effectiveness acceptance curves (CEAC)

Cost-effectiveness acceptance curves (CEAC) represent the probability that the CRT-ICD is cost-effective compared to ICD only, for different willingness to pay (WTP) values. Here we present CEACs for all patients, unrestricted by heart failure events, using either life years (LY) or quality-adjusted life years (QALY) as effectiveness measures.