Rosiglitazone has no adverse effect on cardiac structure and function in type 2 diabetic patients with pre-existing heart failure (HF), UK researchers report.
However, patients taking rosiglitazone suffered more fluid-related events than those taking placebo in addition to other antidiabetic medications in the study.
There are concerns that treatment with thiazolidinediones such as rosiglitazone to control glycaemia can lead to weight gain, fluid retention, and peripheral oedema that could exacerbate symptoms or precipitate decompensation in patients with HF.
Dr Henry Dargie, of Glasgow’s Western Infirmary in the UK, and his team studied 224 patients with type 2 diabetes and New York Heart Association functional class I to II HF, and left ventricular ejection fraction (LVEF) ≤45%.
They randomly assigned patients to receive either rosiglitazone 4–8mg daily or placebo in addition to background anti-diabetic therapy, with treatment adjusted to achieve a plasma glucose level <126mg/dl and HF medications adjusted as appropriate.
Glycaemic control was significantly better in the rosiglitazone group, with a mean reduction in haemoglobin A1c of 0.65% relative to the placebo group (p<0.0001), the team reports in the Journal of the American College of Cardiology.
LVEF was similar in each group after one year of treatment, with a mean difference of 1.49%. LV diastolic and systolic volume index, cardiac index, and LV mass index measures were also similar in each group.
However, there were significantly more cases of new or worsening oedema, at 25.5% versus 8.8%, and increased CHF medication, at 32.7% versus 17.5%, in the rosiglitazone group.
The authors note that most fluid-related events did not lead to early withdrawal from the study, and that the majority were managed by diuretics.
In an accompanying editorial JoAnn Lindenfeld of the University of Colorado, Denver, USA, noted that it was not clear whether the potential benefits of thiazolidinediones on glycaemia and cardiovascular risk factors would be counteracted by potential harm from increased diuretic doses for controlling oedema.
She said guidelines regarding the use of these new agents in HF patients “remain relevant” until new data regarding the management of fluid retention emerge.
J Am Coll Cardiol 2007;49:1696-704