Table 3.
Summary of findings.
| Vagal nerve stimulation plus usual care compared to usual care for heart failure with reduced ejection fraction | ||||||
|---|---|---|---|---|---|---|
| Patient or population: heart failure with reduced ejection fraction | ||||||
| Setting: chronically stable patients enrolled in multiple centers in USA, Europe and Canada | ||||||
| Intervention: vagal nerve stimulation plus usual care | ||||||
| Comparison: usual care | ||||||
| Outcomes | Anticipated absolute effects* (95% CI) |
Relative effect (95% CI) |
No of participants (studies) |
Certainty of the evidence (GRADE) |
Comments | |
| Risk with usual care | Risk with vagal nerve stimulation plus usual care | |||||
| MortalityFollow up: median 6 months | 81 per 1,000 |
96 per 1,000 (66–138) |
OR 1.2 (0.80–1.82) |
1,206 (4 RCTs) |
⊕⊕⊕⊕ HIGH |
VNS has no effect on mortality. |
| NYHA functional classFollow up: median 6 months | 304 per 1,000 |
543 per 1,000 (474–609) |
OR 2.72 (2.07–3.57) |
969 (4 RCTs) | ⊕⊕⊕⊕ HIGH |
There was an improvement of at least one NYHA functional class in VNS group. |
| Quality of lifeFollow up: median 6 months | The mean quality of life was 44.3 | MD 14.18 lower (18.09 lower to 10.28 lower) |
- | 450 (3 RCTs) |
⊕⊕⊕⊕ HIGH |
Quality of life, assessed by the MLwHFQ (lesser is better), showed a consistent improvement in all RCTs. |
| 6-min WTFollow up: median 6 months | The mean 6-min WT was 303.6 meters | MD 55.46 meters higher (39.11 higher to 71.81 higher) |
- | 728 (3 RCTs) |
⊕⊕⊕⊕ HIGH |
6-min walking test distance significantly increased in all trials in VNS groups. |
| NT-proBNP (pg/ml)Follow up: median 6 months | The median NT-proBNP (pg/ml) was 970.5 pg/ml | MD 144.25 pg/ml lower (238.31 lower to 50.18 lower) |
- | 445 (3 RCTs) |
⊕⊕⊕⊕ HIGH |
NP-proBNP levels (a biomarker of heart failure) decreased in most trials analyzed. |
The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI, Confidence interval; OR, Odds ratio; MD, Mean difference; NYHA, New York Heart Association; 6-min WT, 6-min walking test; MLwHFQ, Minnesota Living with Heart Failure Questionnaire; NT-proBNP, N-terminal-pro-brain natriuretic peptide.
GRADE Working Group grades of evidence.
High certainty: We are very confident that the true effect lies close to that of the estimate of the effect.
Moderate certainty: We are moderately confident in the effect estimate: The true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different.
Low certainty: Our confidence in the effect estimate is limited: The true effect may be substantially different from the estimate of the effect.
Very low certainty: We have very little confidence in the effect estimate: The true effect is likely to be substantially different from the estimate of effect.