Edouard Daher

Pilot study of a Web-based compliance monitoring device for patients with congestive heart failure

BACKGROUND Web-based home care monitoring systems can assess medication compliance, health status, quality of life, and physiologic parameters. They may help overcome some of the limitations associated with current congestive heart failure management models. OBJECTIVES This pilot study compared the effects of a self-care and medication compliance device, linked to a Web-based monitoring system, to the effects of usual care alone on compliance with recommended self-care behaviors; medication taking; quality of life; distance walked during a 6-minute walk test; and New York Heart Association Functional Class. We also assessed patient experiences living with the compliance device. METHODS We enrolled 18 patients with Functional Class II-III congestive heart failure in an urban VA Medical Center. The patients were randomized into 2 groups. Group A received usual care plus the compliance device. Group B (controls) received usual care only. Data were collected using the compliance device, the Heart Failure Self-Care Behavior Scale, pill counts, 6-minute walk test, and the Minnesota Living with Heart Failure Questionnaire at baseline and at 3 months follow-up. RESULTS At baseline and at 3 months, there were no differences between the compliance device group and the usual care group in self-care behaviors, pill counts, 6-minute walk-test distance, or Functional Class. However, quality of life improved significantly from baseline to 3-month follow-up (ANOVA, P =.006). This difference was due to an improvement in quality of life for the monitor group (P =.002) but not the usual care only group (P =.113). Patients in the compliance device group had a 94% medication compliance rate, 81% compliance with daily blood pressure monitoring, and 85% compliance with daily weight monitoring as compared to 51% for blood pressure monitoring and 79% for weight monitoring in the usual care group (P = NS). CONCLUSION These are promising pilot results that, if replicated in a larger sample, may significantly improve care and outcomes for patients with heart failure.

Acute ischemic dysfunction alters coronary flow reserve in remote nonischemic regions: potential mechanical etiology identified in an acute canine model.

BackgroundImpaired coronary flow reserve (CFR) has been observed in remote nonischemic regions in patients after myocardial infarction. The mechanism for this impairment in remote nonischemic CFR remains undefined. This study evaluates the effect of progressive regional ischemic dysfunction on function in remote nonischemic regions, and the effect of the extent of dysfunction on remote nonischemic coronary flow and CFR.MethodsIn an anesthetized open-chest canine model (n=7) of acute progressive distal and proximal left anterior descending (LAD) coronary artery occlusion, regional myocardial thickening fraction and coronary flow and CFR were measured with Doppler probes. CFR was assessed by an intracoronary injection of 36 μg of adenosine. Changes in thickening fraction and CFR were evaluated for isovolumic, ejection, and diastolic phases. Changes in resting regional flow were also assessed using radiolabeled microspheres. The extent of the ischemic area was defined as regions of myocardium with endocardial microsphere blood flow less than 0.3 mL/min/g.ResultsThe ischemic area increased from 12%±1% of left ventricle with distal occlusion to 30%±2% of left ventricle with proximal occlusion (P<.001). The LAD thickening fraction decreased significantly from baseline (18%±1%) to distal (−8%±1%,) and proximal (−4%±1%) occlusion (P<.001 for distal and proximal vs baseline). Isovolumic bulging in the LAD region was associated with a progressive increase in thickening fraction in the remote nonischemic left circumflex (LCX) artery region (baseline 12%±1%; distal occlusion 15%±2%, P=.014 vs baseline; proximal occlusion 17%±2%, P=.02 vs baseline). Most of the increase in remote thickening fraction occurred during the isovolumic phase. There was no significant change in resting flow in remote nonischemic LCX regions or global hemodynamic parameters. However, there was a progressive decrease in remote nonischemic CFR (baseline 2.44±0.3), distal occlusion (2.19±0.31; P=.055 vs baseline), and proximal occlusion (1.79±0.22; P=0.004 vs baseline, and P=.012 vs distal occlusion). A progressive decrease in CFR was noted in each phase of the cardiac cycle.ConclusionIn a canine model of acute progressive distal and proximal coronary occlusion, we observed a progressive decrease in CFR in remote nonischemic regions concurrent with an increase in the extent of ischemia. The decrease in remote nonischemic CFR was associated with ischemia-induced isovolumic bulging, which placed the remote regions at a mechanical disadvantage. These observations suggest a potential mechanical etiology for the observed impairment in remote CFR. Alterations in remote nonischemic CFR during acute ischemia may have important clinical implications for perfusion scintigraphy.