Researchers from the DZHK partner sites Lübeck and Munich and from the Heart Center Leipzig at Leipzig University Hospital report in The Lancet the results of their meta-analysis on the optimal timing of invasive coronary angiography in patients with acute coronary syndrome without ST segment elevation. Unlike in the case of acute myocardial infarction with ST segment elevation, the timing of coronary angiography (time between hospital admission and performance of coronary angiography) is controversial. Several studies have explored this question, but all were too small to be able to make a reliable scientific statement in relation to hard end-points such as death or reinfarction. In the past, therefore, scientists summarized the published study data in meta-analyses and observed, among other things, that early coronary angiography reduces the length of stay in hospital as well as the frequency of symptoms of refractory/recurring ischemia. However so far no meta-analysis has succeeded in making a clear statement regarding hard clinical endpoints such as mortality. In this most recently published meta-analysis, which used a more elaborate methodology with individual patient data, DZHK researchers were able to separately analyze patient groups with a particularly high risk. These so-called subgroup analyses indicated for the first time that early coronary angiography could lower mortality in patients with myocardial infarction with ST segment elevation, diabetes mellitus, a high number of risk points and patients over the age of 75 compared with later coronary angiography. However these results, which were generated from subgroups, still need to be validated in a large randomized study. The same DZHK researchers are therefore now using the results of the meta-analysis to plan a large interventional study aimed at testing the hypothesis posed.