A new measurement tool, developed by researchers at the Intermountain Medical Center in Murray, Utah, can stratify mortality risk in heart failure (HF) patients who have been implanted with an implantable cardioverter-defibrillator (ICD), according to a study presented during the rapid fire abstract sessions Sept. 19 at the 15th annual Heart Failure Society of American (HFSA) scientific meeting.
“Many patients with heart failure believe that once they have a defibrillator they are safe,” Benjamin Horne, PhD, director of cardiovascular and genetic epidemiology at the Heart Institute at Intermountain Medical Center said. “However, there are patients who need additional follow-up.“
The Intermountain Risk Score (IMRS) is an inexpensive, gender-specific risk profiling tool that takes age, complete blood count and metabolic profiles into consideration, Horne said. Researchers from Intermountain aimed to evaluate whether patients could be stratified by mortality risk prior to ICD implantation to determine post-ICD survival.
“The Intermountain Risk Score can help physicians know if there are other issues that put their patients at risk,” Horne offered.
For the study, researchers queried 2003-2008 hospital data for adult HF patients who received an ICD and who had a complete blood count workup and basic metabolic profile tested at least three months prior to ICD implantation. IMRS used low, moderate or high-risk IMRS categories to assess mortality risk.
The study enrolled 780 patients; 26.5 percent were female. Mortality at one-year post-ICD implant was 2.4 percent, 11.8 percent and 28.2 percent for low-, moderate- and high-risk patients.
In terms of actual survival, the hazard ratio for moderate risk patients was 2.62 compared with the high-risk group which had a HR of 4.39. During the trial, three patients died from sudden cardiac death.
“This highly predictive tool from simple laboratory values can help refine appropriate patient selection and impact post-ICD implant survival,” Horne concluded.