New research suggests that the use of dronedarone (Multaq) could be dangerous in permanent atrial fibrillation cases due to cardiovascular and mortality risks.

The analysis of data collected during the now halted PALLAS trial revealed a “2.29-fold excess in stroke, myocardial infarction, systemic embolism and death from cardiovascular causes combined among patients taking the rhythm control drug.” Patient hospitalization due to heart failure caused by the drug also increased by 81 percent when compared to those patients taking the placebo.

Researchers presented results from the Permanent Atrial Fibrillation Outcome Study Using Dronedarone on Top of Standard Therapy (PALLAS) at a meeting of the American Hearth Association, reporting that their data revealed dronedarone to be hazardous in such patients.

The overwhelmingly negative results of the PALLAS study left many stunned, as dronedarone had reduced hospitalization and death in the ATHENA trial. Regardless, it is researchers ultimately concluded that it’s reasonable to avoid the use of dronedarone in heart failure and other advanced cardiovascular disease, specifically when in the setting of permanent atrial fibrillation.