Assigning all survivors of an out-of-hospital cardiac arrest (OHCA) to an early coronary angiogram turned out to have no positive influence on the 30-day all-cause mortality. The TOMAHAWK study was not able to establish an advantage over the selective angiogram at a later point of hospitalisation1,2.
Currently, the pros and cons of an instant coronary angiogram in patients with resuscitated OHCA are still under debate. The TOMAHAWK study (NCT02750462) hypothesised that the unselected immediate angiogram would be advantageous for OHCA patients compared with a delayed/selective angiogram. The trial randomised 554 patients over 30 years of age from various sites in Germany and Denmark who met the inclusion criteria of documented OHCA, with return of spontaneous circulation (ROSC). ST-elevation in the ECG was among the reasons for exclusion. The primary endpoint was defined as all-cause mortality at 30 days.
The median age in the cohort was 70 years, roughly 38% had a prior diagnosis of coronary artery disease, and more than 50% presented a shockable first monitored rhythm. The timespan from OHCA to return ROSC was 15 min in both study groups. In the immediate group, 95.5% received an angiogram that was performed within 3 hours after OHCA, while 62.2% of the delayed group patients were taken to the cath lab at a median of 46.9 hours after their arrest.
The analysis of the survival probability found a statistically non-significant difference between the study arms with a hazard ratio of 1.28 (95% CI 1.00–1.63). “If you take the composite of all-cause mortality or severe neurological deficit, this becomes actually statistically significant, yet not accounted for multiple testing; so, this is just hypothesis generating,” Prof. Steffen Desch (University Heart Center Lübeck, Germany) highlighted one of the key secondary outcomes. Several relevant subgroups were also assessed without reaching statistical significance.
Although this has to be considered a negative trial, discussant Prof. Susanna Price (Royal Brompton Hospital, UK) stressed that it answered an important question3. “It gives me information that is useful regarding the opportunity to minimise harm, which is a lot of what critical care is about. So, we do not necessarily have to move these patients very acutely when they just come into the ED. This has implications for resource utilisation, but it also has implications for mobilising patients around the hospital during COVID 19,” she underlined.
References:
1. Desch S. TOMAHAWK: immediate angiography after out-of-hospital cardiac arrest. Hot Line Session. ESC Congress 2021, 27–30 August.
2. Desch, S. New Engl J Med 2021;29 Aug. DOI: 10.1056/NEJMoa2101909.
3. Price S. TOMAHAWK - Discussant review. Hot Line Session, ESC Congress 2021, 27–30 August.