Levosimendan meta-analyses: Is there a pattern in the effect on mortality?

BACKGROUND: Levosimendan is an inodilator developed for treatment of acute heart failure and other cardiac conditions where the use of an inodilator is considered appropriate. Levosimendan has been studied in different therapeutic settings including acutely decompensated chronic heart failure, advanced heart failure, right ventricular failure, cardiogenic shock, septic shock, and cardiac and non-cardiac surgery. This variety of data has been re-analysed in 25 meta-analyses from 15 different international research groups, based on different rationales to select the studies included. METHODS: We here review all previously published meta-analyses on levosimendan to determine any common denominators for its effects on patient mortality. In addition, we also perform a comparative meta-analysis of the six phase II and III randomized double-blind trials which were taken into consideration by the regulatory authorities for the purpose of introducing levosimendan into the market. RESULTS: Irrespective of clinical setting or comparator, all meta-analyses consistently show benefits for levosimendan, with lower relative risk (or odds ratio) for patient mortality. In 3/25 of the meta-analyses these beneficial trends did not reach statistical significance, while in 22/25 significance was reached. The relative risk is consistent overall, and very similar to that obtained in our own meta-analysis that considered only the 'regulatory' studies. CONCLUSION: The existing meta-analyses, now based on a population of over 6000 patients, provide the general message of significant benefits for levosimendan in terms of patient mortality. The weight of evidence is now clearly in favour of usefulness/efficacy of levosimendan, with data from multiple randomized trials and meta-analyses.