Digitalis: a dangerous drug in atrial fibrillation? An analysis of the SPORTIF III and V data

Area of Science:

• Cardiology
• Pharmacology
• Clinical Trials

Background:

• Digitalis is known to improve exercise capacity in heart failure but has no impact on survival.
• Concerns exist that digitalis's inotropic benefits may be offset by adverse effects.
• Atrial fibrillation (AF) patients may react differently to digitalis due to their specific condition.

Purpose of the Study:

• To investigate the impact of digitalis use on mortality in patients with atrial fibrillation (AF).
• To clarify whether the potential adverse effects of digitalis outweigh its benefits in AF patients.
• To analyze digitalis's role in a population primarily benefiting from its rate-controlling properties.

Main Methods:

• Analysis of data from the Stroke Prevention using an ORal Thrombin Inhibitor in atrial Fibrillation (SPORTIF) III and V studies.
• Inclusion of 7329 moderate-to-high risk AF patients randomized to warfarin or ximelagatran.
• Comparison of survival rates between digitalis users and non-users, with multivariate risk factor adjustment.

Main Results:

• Over half (53.4%) of the study population used digitalis.
• Digitalis users exhibited significantly higher mortality rates at baseline (6.5% vs 4.1%, p<0.001).
• This increased mortality persisted after adjusting for baseline risk factors (HR = 1.53, p<0.001).

Conclusions:

• The findings suggest that digitalis, similar to other inotropic drugs, may be associated with increased mortality in AF patients.
• The rate-reducing effect of digitalis in AF might be beneficial, but this could be counteracted by increased mortality risks.
• Results require cautious interpretation as digitalis use was not randomized.