Sleep-disordered breathing in heart failure: identifying and treating an important but often unrecognized comorbidity in heart failure patients.

Sleep-disordered breathing (SDB) is the most common comorbidity in patients with heart failure (HF) and has a significant impact on quality of life, morbidity, and mortality. A number of therapeutic options have become available in recent years that can improve quality of life and potentially the outcomes of HF patients with SDB. Unfortunately, SDB is not part of the routine evaluation and management of HF, so it remains untreated in most HF patients. Although recognition of the role of SDB in HF is increasing, clinical guidelines for the management of SDB in HF patients continue to be absent. This article provides an overview of SDB in HF and proposes a clinical care pathway to help clinicians to better recognize and treat SDB in their HF patients.

Improvement in health-related quality of life after hospitalization predicts event-free survival in patients with advanced heart failure.

BACKGROUND: Health-related quality of life (HRQOL) is a major clinical outcome for heart failure (HF) patients. We aimed to determine the frequency, durability, and prognostic significance of improved HRQOL after hospitalization for decompensated HF. METHODS AND RESULTS: We analyzed HRQOL, measured serially using the Minnesota Living with Heart Failure Questionnaire (MLHFQ), for 425 patients who survived to discharge in a multicenter randomized clinical trial of pulmonary artery catheter versus clinical assessment to guide therapy for patients with advanced HF. All patients enrolled had 1 or more prior HF hospitalizations or chronic high diuretic doses and 1 or more symptom and 1 sign of fluid overload at admission. Improvement, defined as a decrease of more than 5 points in MLHFQ total score, occurred in 68% of patients by 1 month and stabilized. The degree of 1-month improvement differed (P < .0001 group x time interaction) between 6-month survivors and non-survivors. In a Cox regression model, after adjustment for traditional risk factors for HF morbidity and mortality, improvement in HRQOL by 1 month compared to worsening at 1 month or no change predicted time to subsequent event-free survival (P=.013). CONCLUSIONS: In patients hospitalized with severe HF decompensation, HRQOL is seriously impaired but improves substantially within 1 month for most patients and remains improved for 6 months. Patients for whom HRQOL does not improve by 1 month after hospital admission merit specific attention both to improve HRQOL and to address high risk for poor event-free survival.

Recovery of normal ventricular function in patients with dilated cardiomyopathy: predictors of an increasingly prevalent clinical event.

BACKGROUND: This investigation was designed to identify clinical variables associated with recovery of normal ventricular function in patients with dilated cardiomyopathy treated with medical therapy. Recovery of normal ventricular function with medical treatment of patients with dilated cardiomyopathy is observed with increasing frequency. However, the clinical variables associated with such dramatic improvement of ventricular performance are poorly defined. METHODS: Fifty-three patients with dilated cardiomyopathy and reduced ejection fractions who achieved an increase in ejection fraction to > or = 40% with medical therapy were identified during follow-up in a dedicated heart failure clinic. A cohort of patients frequency-matched on baseline ejection fraction who did not recover ventricular systolic function to this magnitude constituted the control group. Clinical variables characterizing the 2 groups were compared by univariable analysis. Variables that significantly differed between the 2 groups were entered in a stepwise logistic regression analysis to identify factors independently associated with recovery of ejection fraction to > or = 40%. RESULTS: In the final logistic regression model, QRS duration, sex, etiology of cardiomyopathy, diabetes, and systolic blood pressure were significantly associated with improvement of ejection fraction to > or = 40%. CONCLUSIONS: Five clinical variables that are independently associated with improvement of left ventricular ejection fraction to normal or near-normal values with medical therapy alone were identified by this modeling process. These variables may be used to discriminate between patients in whom ventricular function will normalize with medical therapy alone and those who will require more aggressive pharmacologic or device therapy.

OptiVol fluid status monitoring with an implantable cardiac device: a heart failure management system.

Early intervention and prevention of hospitalizations would reduce the burden of heart failure on the healthcare system while improving the quality of life of affected patients. Traditional methods of patient assessment, including physical examination and patient report of symptoms, have a low sensitivity for detecting elevations in left ventricular filling pressure, a major precursor of pulmonary congestion and heart failure decompensation. Intrathoracic fluid accumulation during pulmonary congestion leads to decreased impedance across the lung. The OptiVol system in the InSync Sentrycardiac resynchronization therapy-defibrillator, Concerto cardiac resynchronization therapy-defibrillator and Virtuoso implantable cardioverter-defibrillator devices monitors intrathoracic impedance and is intended to recognize early signs of volume accumulation before physical symptoms appear. Through a recent clinical trial, the default setting for the OptiVol system functioned as a predictor of hospitalization with 76.9% sensitivity. Intrathoracic impedance monitoring is not intended to replace careful frequent clinical evaluation of the heart failure patient, but instead aims to complement traditional heart failure management practices.

Effect of cardiac resynchronization therapy on myocardial gene expression in patients with nonischemic dilated cardiomyopathy.

BACKGROUND: Cardiac resynchronization therapy (CRT) improves echocardiographic measures of ventricular structure and function in the failing heart. To determine whether or not these changes are representative of true biologic reverse ventricular remodeling or simply an artifact of an improved contraction pattern, we evaluated changes in myocardial gene expression typical of reverse remodeling before and after chronic CRT. METHODS AND RESULTS: Optimally medically treated patients with nonischemic heart failure meeting standard clinical criteria for CRT were enrolled. Before implantation of a CRT device, baseline echocardiogram and endomyocardial biopsies were obtained. These studies were repeated after 6 months of CRT. Using quantitative reverse-transcriptase polymerase chain reaction, the amount of messenger RNA for selected genes regulating contractile function (sarcoplasmic reticulum Ca2+ ATPase, alpha- and beta-myosin heavy chain [MHC] isoforms, phospholamban [PLB]), and pathologic hypertrophy (beta-MHC and atrial natriuretic peptide [ANP]) was determined from biopsy samples. Changes in gene expression (baseline to 6 months) were determined and correlated to changes in echocardiographic remodeling parameters. Ten patients were enrolled in the study, with 7 completing both baseline and follow-up biopsies and echocardiograms. On average, a significant increase was observed in alpha-MHC and PLB gene expression from baseline to 6 months (P = .016 for both). Beta-MHC levels tended to decrease with CRT (P = .078). Increased alpha-MHC levels correlated best with decreases in left ventricular end-diastolic dimension (P = .073, r = -0.71) and reductions in mitral regurgitation. No significant correlation between ejection fraction and gene expression was found. CONCLUSIONS: These changes in myocardial gene expression support the occurrence of reverse remodeling during chronic CRT. The changes are similar to those reported previously with beta-blockade, but were seen on top of standard drug therapies for heart failure.

Prediction of rehospitalization and death in severe heart failure by physicians and nurses of the ESCAPE trial.

BACKGROUND: The predictive accuracy of physician investigators and nurse coordinators in estimating the risk of rehospitalization and death was determined for 373 hospitalized patients with severe advanced heart failure enrolled in the Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness trial. METHODS AND RESULTS: Estimates were made at discharge, and patients were followed for 6 months after hospitalization. A statistical prognostic model was developed from clinical and laboratory data for the end points of rehospitalization and death. Both nurse and physician predictions of death were generally associated with the observed deaths (c-indices of 0.675 and 0.611), although the nurses' prediction was significantly better (chi-square = 4.75, P = .029). The prediction ability of the prognostic model was similar to the physicians' model (c-index = 0.603). The predictions of rehospitalization were much weaker for nurse, physician and prognostic models. CONCLUSIONS: Nurses' estimations of survival in discharged, advanced-stage heart failure patients were superior to either physicians' or model-based predictions. Not nurses, physicians, or the prognostic model provided useful predictions for rehospitalizations, but this may have resulted from the fact that the rehospitalization estimates did not include the death risk.

Time intervals of cardiac resynchronization therapy in heart failure.

Systolic and diastolic time intervals were measured in 11 patients with heart failure before and 1 and 3 months after the placement of atrial biventricular pacemakers for cardiac resynchronization therapy (CRT). CRT shortened the preejection period, principally by reducing left ventricular (LV) electromechanical delay with lesser reduction of isovolumic contraction time, and shortened the duration of LV systole, with a consequent trend of lengthening diastolic time.