Cardiac resynchronization therapy,
does it really help with Reduced mortality and heart-failure hospitalization in eligible patients with heart failure and reduced ejection fraction?
research showsCardiac resynchronization therapy is rated A because it reduces death and heart-failure hospitalization in selected patients with systolic dysfunction and electrical dyssynchrony. Medtronic-supported CARE-HF (Cleland 2005, N Engl J Med 352(15):1539-1549) enrolled 813 participants; death or cardiovascular hospitalization was 39% versus 55%, HR 0.63 (95% CI 0.51 to 0.77). Solely Guidant-sponsored COMPANION (Bristow 2004, N Engl J Med) enrolled 1,520 participants; primary-composite HRs were 0.81 for CRT-P and 0.80 for CRT-D. Both pivotal trials had industry sponsorship, benefit is strongest with QRS at least 150 ms and left bundle-branch block, and implantation has complications, giving 88 points.
ads claimMarketing may present CRT as a life-extending device for every person with heart failure, regardless of ejection fraction or QRS morphology. The evidence concerns selected patients meeting dyssynchrony and medical-therapy criteria, and an expert heart team must assess procedural suitability and complications.
Useful facts when choosing a product
- CRT paces the right and left ventricles to coordinate ventricular contraction. CRT-D adds defibrillation, whereas CRT-P primarily provides pacing.
- Benefit varies with ejection fraction, QRS duration and morphology, symptoms, rhythm, and use of optimal medical therapy.
- Implantation carries risks including infection, bleeding, pneumothorax, lead displacement or malfunction, and inappropriate shocks, requiring specialist follow-up.
What the research actually shows
Medtronic-supported CARE-HF by Cleland in 2005 (N Engl J Med 352(15):1539-1549) randomized 813 participants and found death or cardiovascular hospitalization in 39% versus 55%, HR 0.63 (95% CI 0.51 to 0.77). Solely Guidant-sponsored COMPANION by Bristow in 2004 (N Engl J Med) randomized 1,520 participants among medical therapy, CRT-P, and CRT-D; primary-composite HRs were 0.81 and 0.80. A 12-trial synthesis of 7,538 participants reproduced lower mortality, although applicability is strongest with QRS at least 150 ms and left bundle-branch block.
Why this is classified as A (88)
In CARE-HF, death or cardiovascular hospitalization among 813 participants was 39% versus 55%, HR 0.63 (95% CI 0.51 to 0.77); in COMPANION, the primary-composite HRs among 1,520 participants were 0.81 for CRT-P and 0.80 for CRT-D. Both pivotal trials had industry sponsorship, benefit is strongest with QRS at least 150 ms and left bundle-branch block, and implantation has complications. However, rule ②-b's manufacturer ceiling does not apply to large hard-endpoint randomized trials of implantable devices, supporting A with 88 points.
Counterpoint. For eligible patients, CRT supplements rather than replaces optimal medical therapy. Comparable benefit should not be assumed with a narrow QRS complex, short life expectancy, or excessive procedural risk.
Rejudgment record. Cross-check applied — Accepted large hard-endpoint successes in CARE-HF and COMPANION, deducted for industry sponsorship of both pivotal trials, strongest applicability to QRS at least 150 ms and left bundle-branch block, and implantation complications, while not applying the rule ②-b ceiling to implantable-device hard-endpoint trials
Sub-claim grades by effect
This ingredient is marketed for several effects. A single overall grade blends strong and weak claims together, so each effect is graded separately here. The overall grade reflects the strongest disconfirming or core claim.
| Effect (sub-claim) | Grade | Basis |
|---|---|---|
| Reduced all-cause mortality in eligible patients with heart failure and reduced ejection fraction | A | CARE-HF and the 12-trial meta-analysis consistently showed a direct mortality benefit. |
| Reduced heart-failure and major cardiovascular hospitalization | A | The CARE-HF primary composite and the individual-patient synthesis support fewer hospitalizations. |
| Improved heart-failure symptoms and functional status | B | Several trials showed improvement, but variation by scale and patient selection makes this less certain than the hard outcomes. |
Cross-check — Codex and Claude
Evidence Table
| Study | Design | Sample | Funding | Endpoint | Result | Weight |
|---|---|---|---|---|---|---|
| Cleland JGF et al. 2005 CARE-HF | Multicenter randomized controlled trial | 404 | Manufacturer-supported trial funded by Medtronic, which also provided a study manager | Primary endpoint: all-cause death or unplanned hospitalization for a major cardiovascular event | 159 of 409 versus 224 of 404, HR 0.63 (95% CI 0.51 to 0.77), P<0.001; the primary endpoint succeeded. | Pivotal direct hard-endpoint trial |
| Bristow MR et al. 2004 COMPANION | Multicenter three-arm randomized controlled trial | 1,520 | Sole industry sponsorship by Guidant | Primary endpoint: all-cause death or all-cause hospitalization | Versus medical therapy, HR 0.81 for CRT-P and 0.80 for CRT-D. | Independent large pivotal hard-endpoint trial |
| Wells GA et al. 2011 | Systematic review and meta-analysis of randomized controlled trials | 7,538 | No separate review funding source reported in the article; some included trials were device-manufacturer supported | Primary synthesis outcome: mortality | Mortality was lower versus medical therapy, RR 0.73 (95% CI 0.62 to 0.85), and versus an implantable cardioverter-defibrillator, RR 0.83 (0.72 to 0.96). | Large replication synthesis |
Receipt — 4 References
All 4 cited sources were verified for existence at the original page (as of 2026-07-24).
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-07-24 · Corrections: none
Cite this verdict
[Chamgap] Cardiac resynchronization therapy x reduced mortality and hospitalization in heart failure with reduced ejection fraction — Evidence Grade A·88. 4 cited sources checked. Source: https://chamgap.com/en/verdicts/heart/cardiac-resynchronization-therapy-hfref-mortality-hospitalization/ · CC BY 4.0CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.
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