CTU Bern


COMFORTABLE AMI compared stents eluting biolimus from a biodegradable polymer with bare-metal stents in patients undergoing primary percutaneous coronary intervention. CTU contributed to the study design and was responsible for the data management, monitoring, and statistical analysis.

This was a single-blind, randomized-controlled trial conducted in 11 trial sites across Europe and Israel. Overall, more than 1,100 patients presenting with acute myocardial infarction were included in the trial. They were randomized to receive either a biolimus-eluting stent with a biodegradable polymer or a standard bare-metal stent during the percutaneous coronary intervention.

For the primary analysis, patients were followed-up for one year but long-term follow-up is ongoing. All cardiovascular events are independently adjudicated. The trial showed that the biolimus-eluting stent is highly effective in reducing the risk for major adverse cardiac events.

COMFORTABLE AMI closed a gap in the evidence on the effects of drug-eluting stents in patients with acute myocardial infarction. The efficient conduct helped to do this in a timely fashion.


Study development and planning

CTU Bern was actively involved in developing the study design and contributed to the successful grant application at the Swiss National Science Foundation (grant 33CM30-124112).

Data management

The trial used an innovative approach to data management. COMFORTABLE AMI was embedded in a large observational study (SPUM-ACS). CTU Bern developed, together with 2mt Software GmbH, a data management solution that integrated all study projects within one system and which allowed participation in several studies while limiting the need for multiple data entry. This innovative system is still in use for other cardiology projects.


CTU Bern was responsible for central data (statistical) monitoring as well as on-site monitoring in the 11 trial sites. The combination of these two approaches helped to perform quality assurance in the most efficient way.

Statistical analysis

All analyses have been done at CTU Bern. Long-term follow-up is on going.

Selected publications

Räber L et al. Comparison of biolimus eluted from an erodible stent coating with bare metal stents in acute ST-elevation myocardial infarction (COMFORTABLE AMI trial): rationale and design. EuroIntervention 2012; 7: 1435-43. doi: 10.4244/EIJV7I12A224.

Räber L et al. Effect of biolimus-eluting stents with biodegradable polymer vs bare-metal stents on cardiovascular events among patients with acute myocardial infarction: the COMFORTABLE AMI randomized trial. JAMA 2012; 308: 777-87. doi: 10.1001/jama.2012.10065.