The OPTIMIZER smart system for managing heart failure

Anker et al. (2019)

Study size, design and location

Observational study n=140. Multicentre study in USA and Europe. Patients with a NYHA class III or IV, QRS duration less than 130 ms and LVEF between 25% and 45% were enrolled.

Intervention and comparator(s)

The OPTIMIZER smart system.

No comparator.

Key outcomes

Results were presented in 3 groups:

and split into patients with:

The results showed a reduction of 75% in hospital admissions (p<0.0001) in the 25% to 45% LVEF group and by a similar rate in the 35% to 45% group. MLWHFQ and NYHA class improved in all 3 groups, (p<0.002). Three-year survival was compared with predicted survival (SHFM) for each patient. The mortality rate was 17.2% for the whole cohort, 20.6% in the 25% to 35% LVEF group, which was similar to the predicted rates. The mortality rate in the 35% to 45% LVEF group was better than predicted (88.0% compared with 74.7%, p=0.046).

Strengths and limitations

No control group. The patients were recruited from a separate large prospective observational study. Inclusion was voluntary and approximately 70% agreed to enrol in this study, which may have introduced selection bias.

Abraham et al. (2018)

Study size, design and location

RCT, n=160 patients with NYHA functional class III or IV symptoms, QRS duration less than 130 ms, and EF 25% to 45%.

Location: USA and Europe.

Intervention and comparator(s)

The OPTIMIZER smart system (n=74).

Comparator: continued medical therapy (n=86).

Key outcomes

Patients in the OPTIMIZER group had improved peak VO₂ (increase 0.84 ml O₂/kg/min), NYHA functional class (p<0.001), 6-min hall walk (p=0.02) and a reduction in the MLWHFQ score (p<0.001) compared with the control group. Cardiovascular death and heart failure hospital admissions was reduced from 10.8% to 2.9% (p=0.048).

There were 7 device-related adverse events.

Strengths and limitations

The treatment arm was unblinded, which could have introduced bias.

Muller et al. (2017)

Study size, design and location

Prospective observational study n=143 with LVEF less than 45%.

Location: USA and Germany (24 sites).

Intervention and comparator(s)

The OPTIMIZER smart system.

No comparator.

Key outcomes

Results were presented in 3 groups (the whole cohort and split into patients with LVEF less than 35% and LVEF 35% or higher). Of the 143 patients, 106 patients (74%) completed the 24-month follow-up. NYHA and MLWHFQ improved in all 3 groups. LVEF in the entire cohort improved at 6 (2.5%), 12 (2.9%), 18 (5.0%), and 24 (4.9%) months. Overall survival at 2 years was 86.4% (95% CI 79.3 to 91.2%). Of the 18 deaths, 7 were considered to be cardiovascular related. Serious adverse events (n=193) were seen in 91 subjects and similarly distributed between groups with LVEF less than 35% and LVEF 35% or higher, and according to the authors were similar to other device trials for heart failure. The authors reported that there were an insufficient number of subjects who had follow-up data for 6-min walk or peak VO₂ assessment to enable a comparative analysis.

Strengths and limitations

No control group.

Kloppe et al. (2016)

Study size, design and location

Retrospective observational study n=68 with NYHA class II or III symptoms and normal QRS duration. Location: Germany.

Intervention and comparator(s)

The OPTIMIZER smart system (mean follow-up 4.5 years, range 0.25 to 10.3 years).

No comparator.

Key outcomes

Results were compared with predicted survival (SHFM) pre-implant for each patient. There were 16 deaths during the follow-up period, 6 were cardiovascular related. Mortality rates (Kaplan–Meier analysis) at 1 year (0% compared with 6.1%), 2 years (3.5% compared with 11.8%) and 5 years (14.2% compared with 27.7%) were lower with the OPTIMIZER smart system compared with those predicted by SHFM (p=0.007).

Strengths and limitations

A retrospective observational study. Other factors such as drug therapy were not assessed, which could have influenced the results.

Liu et al. (2016)

Study size, design and location

Case-control study n=41 with NYHA class III symptomatic heart failure and EF less than 40%. Location: Hong Kong.

Intervention and comparator(s)

The OPTIMIZER smart system (mean follow-up 75 months).

No comparator.

Key outcomes

The results showed that all-cause mortality for the entire cohort was significantly reduced in the OPTIMIZER group 41% compared with the control 71% (p=0.001). Subgroup analysis showed that the all-cause mortality of OPTIMIZER patients with an EF of less than 25% did not significant differ compared with the control, however patients with a EF between 25% and 40% had a significant survival benefit (p<0.001). Admission rates were also significantly reduced for OPTIMIZER in the EF 25% to 40% subgroup (p=0.001).

Strengths and limitations

There were 6-year follow-up data but the sample size was relatively small.

Kuschyk et al. (2015)

Study size, design and location

Single site retrospective analysis n=81 with symptomatic heart failure and reduced LVEF. Location: Germany.

Intervention and comparator(s)

The OPTIMIZER smart system (mean follow-up 34.2 months, range 6 to 123 months).

Key outcomes

The results showed significant improvements in NYHA class (p=0.001), LVEF (p=0.001), NT-proBNP levels (p=0.001). Quality of life measured by MLWHFQ also improved. Mortality rates appeared to be lower than estimated compared with the predicted rate calculated using a MAGGIC score.

Strengths and limitations

Small single-centre retrospective analysis. Drug therapy was administered at the discretion of the treating clinician and not assessed as part of the study, which could have had an effect on the results.

Abbreviations: EF, ejection fraction; LVEF, left ventricular ejection fraction; MAGGIC, meta-analysis global group in chronic heart failure; MLWHFQ, Minnesota Living With Heart Failure questionnaire; NT-proBNP, N-terminal pro-brain natriuretic peptide; NYHA, New York Heart Association; peak VO₂, peak oxygen uptake; RCT, randomised controlled trial; SHFM: Seattle Heart Failure Model.