An implantable hemodynamic monitor (IHM) may help to guide medical treatment in a large subgroup of patients with heart failure—those with diastolic heart failure (DHF), according to a subgroup analysis in the COMPASS-HF trial that appeared in the December issue of Journal of Cardiac Failure.
Michael R. Zile, MD, of Medical University of South Carolina, Charleston, S.C., and colleagues analyzed data on DHF patients enrolled in a larger randomized trial evaluating the IHM, which is a surgically implanted device that continuously records data on heart function, which can then be downloaded for analysis by healthcare professionals.
The main COMPASS-HF study included 274 patients with all types of HF. The results showed that the risk of HF events was reduced by about 20 percent in patients treated with the IHM, although the difference was not statistically significant. The new analysis focused on the subgroup of patients with DHF. In DHF, the heart still has normal ejection fraction, but no longer relaxes sufficiently to fill with blood normally.
In the COMPASS-HF study, the researchers found that 70 patients with DHF were randomly assigned to receive the IHM, while the rest were managed without the IHM.
As in the main study, Zile and colleagues found that DHF patients who received the IHM device had a 20 percent reduction in HF events, although the difference was not significant. A 29 percent reduction in the risk of hospitalization for HF was also non-significant.
They found that the IHM did lead to some significant changes in patient management, including more frequent adjustments in the dose of diuretics—a key part of treatment for heart failure. As in the larger study, the IHM device was safe in DHF patients, with a low complication rate.
Patients with chronic HF need careful medical management to avoid episodes of acute decompensation. Few studies have focused on patients with DHF, even though they account for about half of all patients with heart failure.
Based on the new analysis, Zile and colleagues found that there is as yet no evidence that using the IHM device to guide treatment reduces the risk of decompensation and HF events in patients with DHF. The IHM does appear safe for patients with HF, with a very low risk of complications. In addition, DHF patients receiving the IHM device show a trend toward lower rates of heart failure events, including hospitalization related to HF.