Table 1.
Selected Input Parameters*
| Base Case | Range | Source | |
|---|---|---|---|
| Event Probabilities (Monthly)† | |||
| CHAMPION cohort | |||
| Baseline All-Cause Mortality (%)‡ | 0.99 | 0.66–1.31 | (3) |
| Baseline Heart Failure Hospitalization (HFH)(%)§ | 8.76 | 4.38–13.15 | (3) |
| Inpatient HFH Mortality (%) | 3.90 | 3.60–4.20 | (11,12) |
| Relative Risk of Death after HFH** | 3.32 | 1.00–4.98 | (13) |
| Non-heart Failure Hospitalization (%) | 8.30 | 6.99–9.60 | (3) |
| Relative Risk (RR) of Preserved Ejection Fraction (pEF) Subgroup, compared to Reduced Ejection Fraction (rEF) Subgroup | |||
| RR of All-Cause Mortality, pEF vs. rEF | 0.52 | 0.43–1.00 | (6–9) |
| RR of HFH, pEF vs. rEF | 0.64 | 0.54–1.00 | (6–9) |
| RR of HFH Inpatient Mortality, pEF vs. rEF | 0.74 | 0.67–1.00 | (6–9) |
| CHARM Cohort†† | |||
| Heart Failure Mortality (%)‡‡,‡ | 0.66 | 0.43–0.89 | (5,6) |
| Baseline HFH (%)‡‡,§ | 3.11 | 2.32–3.89 | (5,6) |
| CardioMems Arm Specific Parameters | |||
| RR of HFH, compared to usual care | 0.63§§ | 0.52–0.77 | (3) |
| Placement Failure (%) | 4.35 | 2.68–6.01 | (3) |
| Costs ($) | |||
| Cost of Heart Failure Hospitalization | 12,832 | 8,341–16,750 | (17) |
| Cost of CardioMems Device | 17,750 | 8,875–35,500 | (4) |
| Cost of CardioMems Placement*** | 1,129 | 564–2,258 | (4,19) |
| Monthly Cost of CardioMems Device Management | 68 | 34–136 | ††† |
| Utilities | |||
| Baseline Utility, CHAMPION Cohort‡‡‡ | 0.55 | 0.51–0.75 | (3,14) |
| Baseline Utility, CHARM Cohort‡‡‡ | 0.66 | 0.64–0.68 | (14,23) |
| Disutility of Heart Failure Hospitalization | 0.059 | 0–0.11 | (15) |
| Utility of CardioMems Device for first 12 months‡‡‡ | 0.010 | 0–0.019 | (3,14,15) |
| Utility of CardioMems Device after first 12 months‡‡‡ | 0.004 | 0–0.019 | (3,14,15) |
Abbreviations: HFH: heart failure hospitalizations; RR: relative risk; pEF: preserved ejection fraction; rEF: reduced ejection fraction; MLWHF: Minnesota Living with Heart Failure.
Listed probabilities refer to the probabilities for patients with rEF. Probabilities of pEF calculated via the RR between pEF and rEF groups.
Adjusted for age with an exponential model (Supplement for further details).
Heart failure hospitalization probability adjusted by a monthly decreasing exponential model based on model stage to adjust for decreasing hospitalization rate with increasing time from initial hospitalization. This was set as constant after 17 months (Supplement for further details).
Increased risk for two months prior to returning to baseline.
Only differed from CHAMPION cohort with regards to hospitalization probability, mortality probability, and baseline quality of life. Used the same exponential models as CHAMPION cohort to adjust hospitalization and mortality probabilities.
Estimated from patients from all three CHARM trials and adjusted for those with a previous HFH and ejection fraction composition.
rEF subgroup RR of 0.67; pEF subgroup RR of 0.48.
Consists of Medicare professional reimbursement for right-heart catheterization, angiography, and CardioMems placement. CardioMems placement reimbursement not defined; estimated to be equal to a temporary transvenous cardiac electrode placement.
Estimated secondary to time associated with monitoring program (Dr. Liviu Klein, personal communication, November, 2015) and provider wages (20,21) (see Supplement for details)
MLWHF scores converted into EQ-5D scores.