Wednesday, May 30, 2007

Tolvaptan has no effect on left ventricular (LV) remodeling

Cardiovascular News

Tolvaptan fails to affect LV remodeling

30 May 2007

MedWire News: A year of treatment with the vasopressin V2 receptor antagonist tolvaptan has no effect on left ventricular (LV) remodeling in patients with chronic systolic heart failure (HF) receiving evidence-based medical therapy, results of a small randomized trial show.

However, the investigators note that tolvaptan use was associated with a significant reduction in the combined endpoint of time to mortality or HF hospitalization in a non-prespecified analysis.

Tolvaptan has previously been shown to reduce body weight in HF patients, consistent with improved volume homeostasis, and to normalize serum sodium in hyponatremic HF patients, explain James Udelson (Tufts University School of Medicine, Boston, Massachusetts, USA) and colleagues.

For the current study, the researchers looked at the effects of tolvaptan on changes in LV volumes that are driven by LV remodeling.

They randomly assigned 120 patients with New York Heart Association class II-III HF and LV ejection fraction ≤30% to either tolvaptan 30 mg/day or placebo, on top of standard background medical therapy.

Quantitative radionuclide ventriculography at baseline and at 1-year follow-up showed that there was a small reduction of 1.8 ml/m2 in the LV end-diastolic volume index with tolvaptan and no reduction with placebo. The between-group difference was nonsignificant.

Six (5%) deaths and 21 (18%) hospitalizations for HF occurred in the tolvaptan group compared with 11 (9%) and 34 (28%) deaths and HF hospitalizations, respectively, in the placebo group.

“In a time-to-event analysis there was a significant favorable effect of tolvaptan on the composite of mortality or HF hospitalization (p<0.03),” the authors report in the Journal of the American College of Cardiology.

There were no significant differences between groups in measures of quality of life using standardized questionnaires, but patients’ assessments of their global status, categorized as “better,” “worse,” or “unchanged” revealed that more patients who received tolvaptan reported a score of “better” than did patients in the placebo group at both 28-week and 1-year visits.

“In a well-treated population of stable HF patients, there was no significant effect of tolvaptan therapy on LV volumes observed during 1 year of therapy,” Udelson and colleagues conclude.

Link: J Am Coll Cardiol 2007; 49: 2151-2159

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