Ambulatory Hemodynamics in Patients With Chronic Heart Failure: Implications for Volume Management in Elderly Patients

Single subject design: Use of time series analyses in a small cohort to understand adherence with a prescribed fluid restriction

PURPOSE

This paper presents a secondary in-depth analysis of five persons with heart failure randomized to receive an education and behavioral intervention on fluid restriction as part of a larger study.

METHODS

Using a single subject analysis design, time series analyses models were constructed for each of the five patients for a period of 180 days to determine correlations between daily measures of patient reported fluid intake, thoracic impedance, and weights, and relationships between patient reported outcomes of symptom burden and health related quality of life over time.

RESULTS

Negative relationships were observed between fluid intake and thoracic impedance, and between impedance and weight, while positive correlations were observed between daily fluid intake and weight.

CONCLUSIONS

By constructing time series analyses of daily measures of fluid congestion, trends and patterns of fluid congestion emerged which could be used to guide individualized patient care or future research endeavors. Employment of such a specialized analysis technique allows for the elucidation of clinically relevant findings potentially disguised when only evaluating aggregate outcomes of larger studies.

Rationale and Design of the Left Atrial Pressure Monitoring to Optimize Heart Failure Therapy Study (LAPTOP-HF)

BACKGROUND

Daily measurements of left atrial pressure (LAP) may be useful for guiding adjustments in medical therapy that prevent clinical decompensation in patients with severe heart failure (HF).

STUDY DESIGN

LAPTOP-HF is a prospective, multicenter, randomized, controlled clinical trial in ambulatory patients with advanced heart failure in which the safety and clinical effectiveness of a physician-directed patient self-management therapeutic strategy based on LAP measured twice daily by means of an implantable sensor will be compared with a control group receiving optimal medical therapy. The trial will enroll up to 730 patients with New York Heart Association functional class III symptoms and either a hospitalization for HF during the previous 12 months or an elevated B-type natriuretic peptide level, regardless of ejection fraction, at up to 75 investigational centers. Randomization to the treatment group or control group will be at a 1:1 ratio in 3 strata based on the ejection fraction (EF > or ≤35%) and the presence of a de novo CRT device indication.

SUMMARY

LAPTOP-HF will provide essential information about the role of implantable LAP monitoring in conjunction with a new HF treatment paradigm across the spectrum of HF patients.