Shift in Paradigm for HF Monitoring Needed
In the old paradigm of monitoring HF patients the focus was on clinical congestion, which involves patient self-monitoring of signs, symptoms and daily weights, or remote telemonitoring systems. The new paradigm, however, focuses on hemodynamic congestion, including monitoring of intra-cardiac and pulmonary artery pressures and treatment of elevated pressures without symptoms, explained William T. Abraham, MD, of Ohio State’s Heart and Vascular Center, Columbus.
Out with the old
One problem with the old paradigm, Abraham said, is that body weight monitoring has a low sensitivity for predicting HF hospitalizations. Studies published by Lewin et al in the European Heart Journal in 2005 and Abraham et al in Congestive Heart Failure in 2011 show that the sensitivity of weight change in predicting episodes of HF decompensation or HF hovers around 10% to 20%.
Data suggest, however, that a relationship between pressure and risk for HF hospitalization exists, according to Abraham. He cited results from the COMPASS-HF trial, which was one of the early experiences with an implantable right ventricular pressure monitor in HF, that show when pressure falls below 25 mm Hg, there is a near linear decrease in risk for hospitalization to about 15 mm Hg.
In with the new
Two trials support this hypothesis, Abraham said. The prospective, multicenter, single blind CHAMPION trial examined patients randomly assigned to HF standard of care, including monitoring of signs, symptoms, daily weight change and other clinically used standard of care monitoring systems (n=280) or management based on hemodynamic monitoring with the CardioMEMS Heart Failure Monitoring System plus traditional information (n=270). The primary endpoint was HF hospitalization at 6 months with extended follow-up averaging 15 months. The trial demonstrated a significant benefit of hemodynamic monitoring (see Figure).
Abraham also discussed another system, an implanted left atrial pressure monitor (HeartPOD, St. Jude Medical), that is undergoing evaluation. In addition to pressure monitoring, a unique aspect of the system is the method of use, which employs a physician-directed, patient self-management paradigm. Patients manage their left atrial pressure on a day-to-day basis and use a physician-prescribed algorithm to direct treatment. An evaluation of a 40-patient pilot study — the HOMEOSTASIS trial — demonstrated reductions in the annualized HF event rate per year from 1.4 during the 12-month period before enrollment to 0.28 after 3 months of titration/stability periods (P<.001). The device is now being studied in an ongoing pivotal trial of approximately 700 patients called Laptop-HF.
“Newer approaches are needed to reduce preventable readmissions for HF. Implantable hemodynamic monitors are promising and represent a paradigm shift in HF,” Abraham concluded.
- Dr. Abraham reports receiving consultant fees/honoraria from numerous device manufacturers.