Tolvaptan for Heart Failure, Systematic Review and Meta-Analysis of Trials.

The vasopressin type 2 receptor antagonist tolvaptan (TLV) is available to treat congestion in patients with heart failure. However, there is paucity of evidence guiding its use, and lack of evidence of its long-term efficacy. Our objectives are to perform a systematic review of studies examining the effects of TLV in patients with heart failure; and a quantitative meta-analysis comparing primary and secondary outcomes between TLV and placebo. Only double-blinded randomized controlled trials, with no restriction on the language or the time of publication, were included. Our main outcome measures were all-cause mortality, change in body weight, change in urine volume, and change in serum sodium. Extracted summary estimates included mean difference and SD for change in body weight, change in urine volume and change in serum sodium levels, and hazard ratio with 95% confidence interval for all-cause mortality. We found 8 double-blinded randomized controlled trials, seven of which were included in this meta-analysis. Assessment of risk of bias was conducted by investigating random sequence generation, allocation concealment, blinding, completeness of outcome data, and potential for selective reporting. We found no evidence of significant bias. TLV showed benefits in reducing body weight, increasing urine volume, and increasing serum sodium. No reduction in mortality was detected. However, the subgroup of patients with hyponatremia might have better mortality outcome with TLV. TLV seemed to be safe, as it did not cause worsening of the renal function or hypotension. In conclusion, a meta-analysis of the published literature suggests short-term benefits of TLV. However, the impact on mortality is inconclusive.