Immunomodulation therapy (IMT) seems to prolong life and delay readmission for a large proportion of heart failure patients, a study suggests.
Study leader Dr Guillermo Torre-Amione of Methodist Hospital, Houston, USA, said the large, placebo-controlled trial found heart failure patients with no history of myocardial infarction and those within New York Heart Association (NYHA) class II who received IMT had around 25% and 40% reductions in a composite of time to death and hospitalisation for cardiac reasons.
But Dr Karen Sliwa, of Witwatersrand University, Johannesburg, South Africa, and Dr Aftab Ansari, of Emory University School of Medicine, Atlanta, USA, arn that the therapy could raise patients’ susceptibility to infections and cancer, or trigger autoimmune disease.
Dr Torre-Amione and team studied 2,426 patients with NYHA functional class II-IV chronic heart failure and left ventricular systolic dysfunction who had been hospitalised for heart failure or intravenous drug therapy within the past year.
Patients in the treatment arm received IMT on days 1, 2, and 14 and then every 28 days for at least 22 weeks.
For IMT, anticoagulated blood taken from the patients was exposed to ozone and ultraviolet light and then re-injected.
During a mean follow-up of 10.2 months, the incidence of primary events was statistically comparable in the treatment and placebo groups (339 vs 429, HR=0.92).
Dr Torre-Amione and team say the null result “was disappointing in view of increasing evidence that inflammation plays a part in the progression of heart failure”.
However, IMT was associated with a 26% reduction in the primary events in patients with no history of myocardial infarction (n=919) and a 39% reduction among patients with NYHA class II heart failure (n=689).
The researchers note that, compared with the entire population, these subgroups consisted of younger patients with baseline variables consistent with less severe disease.
Thus, IMT may only be effective when started early, before permanent cellular damage, they suggest.
In their editorial, Dr Sliwa and Dr Ansari said there are several “potential problems” with the approach taken by Dr Torre-Amione’s team.
Susceptibility to opportunistic infections may increase and elimination of potentially malignant cells may decrease.
While neither was reported, the effects may be slow to emerge, they commented.
They added: “The study was too short to detect new onset of autoimmune diseases.
“Long-term follow-up of patients receiving this type of therapy should be mandatory.”