Post-MI prophylactic arrhythmia suppression,
does it really help with Prevention of sudden death by suppressing ventricular ectopy?
research showsThe grade is D with 34 points. CAST and SWORD tested different drugs (Class Ic versus pure d-sotalol) in different populations with different primary outcomes. CAST found arrhythmic death or cardiac arrest in 33/730 versus 9/725, RR 3.6 (95% CI 1.7 to 8.5), and SWORD found all-cause death in 78/1,549 versus 48/1,572, RR 1.65 (1.15 to 2.36). Both showed harm in the same direction, but they were not repeat trials measuring the same thing.
ads claimReducing premature beats on an electrocardiogram does not mean fewer deaths. CAST and SWORD both showed harm, but their different drugs, populations, and primary outcomes prevent treating them as repeat trials.
Useful facts when choosing a product
- Korean distribution was confirmed for Tambocor 50 mg flecainide, whose label contraindicates use for asymptomatic ventricular ectopy or nonsustained ventricular tachycardia after myocardial infarction.
- Current Korean sales of encainide and pure d-sotalol were not confirmed.
- Racemic sotalol and the pure d-sotalol used in SWORD are not the same product.
Chamgap Semantic Classification Code
Candidate index · review held
M.post-myocardial-infarction-prophylactic-arrhythmia-suppression-strategy-using-encainide-flecainide-or-pure-d-sotalol.intravenous.sudden-death-by-suppressing-ventricular-ectopy.prevent.placeboMedicinal interventions > post-myocardial-infarction prophylactic arrhythmia-suppression strategy using encainide/flecainide or pure d-sotalol > Intravenous > sudden death by suppressing ventricular ectopy > Occurrence-prevention claim > Placebo
An automated migration candidate, not an issued permanent code; exact claim scope remains under review. This machine-generated migration candidate helps retrieval but is not a permanent assignment. The original verdict ID and URL remain authoritative.
What the research actually shows
The CAST preliminary and final papers are reports from the same NCT00000526 trial. The preliminary primary analysis included 1,455 participants and the final cumulative analysis 1,498; CAST was supported by NHLBI/NIH contracts. SWORD randomized 3,121 participants, followed them for a mean 148 days, and was supported by Bristol-Myers Squibb. The investigator groups and funding sources did not overlap. Both trials stopped early for harm, and an exact missing-data method could not be secured in accessible reporting.
Why this is classified as D (34)
Both trials had harm intervals excluding no effect, but their different drugs, populations, and primary outcomes preclude counting them as repeated refutation. H, R1, I1, E−, C0, B2, and the large hard-outcome trial yield D with 34 points.
Counterpoint. Flecainide remains a prescription drug for other indications under specialist supervision. This verdict is restricted to prophylactic suppression of asymptomatic or mildly symptomatic ventricular arrhythmias after myocardial infarction.
Rejudgment record. Cross-check applied — Cross-checked CAST and SWORD for primary outcomes, randomized and analyzed counts, harm estimates, drug classes, funding, and duplicate reports from one trial
| Endpoint | H | Hard endpoint - actual events such as death |
| Replication | R1 | Single confirmatory trial |
| Independence | I1 | Mixed funding sources |
| Effect size | E- | Harm increased in the trials |
| Precision | C0 | The confidence interval leaves room for benefit |
Stored derived and displayed grades match; this is not a current recalculation or validity check (D).
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 |
|---|---|---|
| Prevent sudden death by suppressing ventricular ectopy with Class Ic drugs | D | CAST found significantly increased arrhythmic death or cardiac arrest. |
| Prevent post-MI death with pure d-sotalol | D | SWORD found significantly increased all-cause mortality. |
Cross-check — AI research and Codex final gate
Evidence Table
| Study | Design | Sample | Funding | Endpoint | Result | Weight |
|---|---|---|---|---|---|---|
| Echt DS, Liebson PR, Mitchell LB, Peters RW, Obias-Manno D, Barker AH, Arensberg D, Baker A, Friedman L, Greene HL, Huther ML, Richardson DW. 1991 CAST; Cardiac Arrhythmia Suppression Trial (CAST) Investigators. 1989 preliminary report | Multicenter randomized double-blind placebo-controlled trial; both papers report the same trial | Preliminary primary analysis 1,455 (730/725); final cumulative analysis 1,498 (755/743) | NHLBI/NIH contract support | Arrhythmic death or cardiac arrest | 33/730 (4.5%) versus 9/725 (1.2%), RR 3.6 (95% CI 1.7 to 8.5); final all-cause death or cardiac arrest 63/755 versus 26/743 | Large hard-outcome trial of Class Ic drugs |
| Waldo AL, Camm AJ, deRuyter H, Friedman PL, MacNeil DJ, Pauls JF, Pitt B, Pratt CM, Schwartz PJ, Veltri EP. 1996 SWORD | Multinational randomized double-blind placebo-controlled trial | 3,121 randomized and analyzed (1,549/1,572) | Supported by Bristol-Myers Squibb | All-cause mortality | 78/1,549 (5.0%) versus 48/1,572 (3.1%), RR 1.65 (95% CI 1.15 to 2.36), P=0.006 | Large hard-outcome trial of pure d-sotalol in a different population with a different endpoint |
Receipt — 4 References
All 4 cited sources were verified for existence at the original page (as of 2026-08-15).
Final verification and publication gate: Codex · Evidence date: 2026-08-15 · Corrections: none
Cite this verdict
[Chamgap] Post-MI prophylactic arrhythmia suppression x prevention of sudden death — Evidence Grade D·34. 4 cited sources checked. Source: https://chamgap.com/en/verdicts/heart/post-mi-prophylactic-arrhythmia-suppression-sudden-death-prevention/ · CC BY 4.0CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.
What this document does and does not do
Chamgap is an information source. It reports what research has and has not confirmed; it does not tell readers what to take or buy. That decision belongs to readers and, when needed, medical or legal professionals. This verdict reflects literature available up to the search date and may change as new research appears. Nothing here is medical advice.