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Bayesian Reanalyses of the Trials TOMAHAWK and COACT
Tharusan Thevathasan1, Anne Freund2, Eva Spoormans3
1DZHK (German Center for Cardiovascular Research), Germany; Department of Cardiology, Angiology and Intensive Care Medicine, Deutsches Herzzentrum der Charité (DHZC), Campus Benjamin Franklin, Berlin, Germany; Berlin Institute of Health, Berlin, Germany.
Insights
Bayesian reanalysis suggests immediate coronary angiography after cardiac arrest without ST-elevation may increase 30-day mortality. A delayed strategy is likely preferred, shifting understanding from neutral to potentially harmful. Further trial results are pending.
Area of Science:
- Cardiology
- Clinical Trials
- Biostatistics
Background:
- Two large trials (TOMAHAWK, COACT) investigated immediate vs. delayed coronary angiography in out-of-hospital cardiac arrest (OHCA) patients without ST-elevation.
- Both trials yielded neutral results for short-term mortality, though TOMAHAWK suggested a non-significant trend towards harm with immediate angiography.
- Bayesian probabilistic analyses offer a potential method for deeper clinical interpretation of these trial findings.
Purpose of the Study:
- To reanalyze the TOMAHAWK and COACT trials using a Bayesian statistical framework.
- To explore the impact of different prior assumptions on the interpretation of immediate vs. delayed coronary angiography outcomes.
Main Methods:
- Post hoc Bayesian logistic regression analyses were conducted on data from the TOMAHAWK and COACT trials, both separately and combined.
- The primary endpoint was 30-day all-cause mortality.
- Analyses incorporated a range of priors, including "flat," "neutral," "optimistic," and "pessimistic" assumptions.
Main Results:
- Bayesian reanalysis of TOMAHAWK indicated a high posterior probability (90-97%) of increased 30-day mortality with immediate angiography across all priors.
- COACT showed odds ratios for 30-day mortality ranging from 0.98 to 1.11.
- Combined analysis of both trials demonstrated a high probability (83-95%) of increased mortality with immediate angiography, with all priors suggesting a trend towards harm.
Conclusions:
- Bayesian reanalysis suggests a high probability of increased 30-day mortality with immediate coronary angiography compared to delayed/selective angiography in OHCA patients without ST-elevation.
- These findings challenge the "neutral" interpretation of TOMAHAWK and COACT, indicating a potentially "harmful" effect of immediate angiography.
- A delayed angiography strategy may be preferable in clinical practice pending results from the DISCO trial.
Background:
The timing of coronary angiography in patients with successfully resuscitated out-of-hospital cardiac arrest and missing ST-segment elevations on the electrocardiogram has been investigated in 2 large randomized controlled trials, TOMAHAWK (Angiography After Out-of-Hospital Cardiac Arrest Without ST-Segment Elevation) and COACT (Coronary Angiography After Cardiac Arrest Trial). Both trials found neutral results for immediate vs delayed/selective coronary angiography on short-term all-cause mortality. The TOMAHAWK trial showed a tendency towards harm with immediate coronary angiography, though not statistically significant with traditional frequentist methods. Probabilistic analyses of both trials may enable greater clinical understanding of the trial findings.
Objectives:
The purpose of this study was to perform reanalyses of both trials within a Bayesian framework.
Methods:
Post hoc analyses of both multicenter randomized controlled trials were performed in both cohorts separately and combined. The primary endpoint, 30-day all-cause mortality, was analyzed using Bayesian logistic regression. A spectrum of priors included "flat," "neutral," "optimistic," and "pessimistic" priors based on assumptions made when designing both trials.
Results:
In the TOMAHAWK trial, immediate coronary angiography showed a very high posterior probability of increased mortality between 90% and 97% across all priors. The ORs across all priors were directed towards harm. Similarly, COACT showed odds ratios ranging from 0.98 to 1.11 for the 30-day mortality endpoint. When combining both trials, immediate coronary angiography showed a high probability of increased mortality between 83% and 95%, again with ORs across all priors indicating a direction towards harm.
Conclusions:
Bayesian reanalyses showed a very high probability of increased 30-day mortality risk with immediate compared with delayed/selective coronary angiography in the TOMAHAWK trial and combined trial cohort. These findings may shift the current understanding of both trials from a "neutral" towards a likely "harmful" effect of immediate coronary angiography after successfully resuscitated out-of-hospital cardiac arrest without ST-segment elevations. Therefore, adoption of a delayed strategy of coronary angiography might be preferred in clinical practice until the results of the DISCO (Direct or Subacute Coronary Angiography in Out-of-Hospital Cardiac Arrest) trial become available.
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