Change in intrathoracic impedance measures during acute decompensated heart failure admission: results from the Diagnostic Data for Discharge in Heart Failure Patients (3D-HF) Pilot Study.

BACKGROUND: Despite the high number of admissions for acute decompensated heart failure (ADHF), there are no specific criteria for discharge readiness. A number of patients have implantable devices that might provide data to assist in determining readiness for discharge. METHODS AND RESULTS: The 3D-HF (Diagnostic Data for Discharge in Heart Failure Patients) study was a prospective observational pilot study enrolling HF patients with Optivol-capable cardiac devices within 48 hours of a hospital admission characterized by worsening HF symptoms. The primary end point was the difference in times from admission to 50% improvement in impedance and to when patient was medically ready for discharge. The nonparametric sign test was used to determine if the difference was significant. A total of 20 subjects were enrolled over a 24-month period. The median ADHF length of stay was 7 days. Of the 20 subjects, 18 achieved the intrathoracic impedance improvement threshold before discharge. The time to reach the threshold for improvement was 2.5 days (interquartile range 2.0-6.0). The difference between days to 50% impedance and days to provider's discharge decision was 3.0 (P = .0072). CONCLUSIONS: Intrathoracic impedance changes were evident over a short duration in the majority of patients admitted for ADHF and may be a potential criterion for discharge readiness.

Pharmacologic therapy of chronic heart failure.

Over the past 2 decades, investigators have learned more about the pathophysiologic changes that occur in systolic and diastolic dysfunction. Ironically, in some cases, the biologic pathways that have protected the heart during acute dysfunction are the same pathways that cause progressive deleterious effects with chronic activation. In particular, it is the activation of the neurohormonal system that has a significant impact on disease progression. As a result, the neurohormonal system has provided a key target for pharmacologic therapy in patients with heart failure secondary to systolic dysfunction. These targets include the renin-angiotensin-aldosterone system as well as the sympathetic nervous system. Neurohormonal manipulation, however, is often ineffective in the pharmacologic therapy of patients with endstage heart failure, therefore other treatment strategies - including the use of inotropic agents to improve pump function and diuretics to control fluid balance are needed.

Hyponatremia and vasopressin antagonism in congestive heart failure.

In a national heart failure registry, hyponatremia (serum sodium < 130 mEq/L) was initially reported in 5% of patients and considered a risk factor for increased morbidity and mortality. In a chronic heart failure study, serum sodium level on admission predicted an increased length of stay for cardiovascular causes and increased mortality within 60 days of discharge. Hyponatremia in patients with congestive heart failure (CHF) is associated with a higher mortality rate. Also, by monitoring and increasing serum sodium levels during hospitalization for CHF, patient outcomes may improve. This review describes the pathophysiology of hyponatremia in relation to CHF, including the mechanism of action of vasopressin receptors in the kidney, and assesses the preclinical and clinical trials of vasopressin receptor antagonists--agents recently developed to treat hyponatremia. In hospitalized patients with CHF, hyponatremia plays a major role in poor outcomes. Vasopressin receptor antagonists have been shown to be safe and effective in clinical trials in patients with hyponatremia.

Modified inferior vena caval anastomosis to reduce tricuspid valve regurgitation after heart transplantation.

Postoperative tricuspid valve regurgitation is moderate to severe in 15% to 20% of heart transplant recipients despite use of the bicaval surgical technique. We hypothesized that the regurgitation might be partly due to increased tension on the donor right atrium. To study the right atrial distortion, we modified the standard bicaval anastomosis. Our technique involves augmenting the donor right atrial anterior wall with a flap of the recipient's right atrium, which is left attached in continuity with the anterior aspect of the inferior vena cava along 65% of its circumference. We measured tricuspid regurgitation, right atrial area, and right atrioventricular diameter in 7 consecutive patients who underwent orthotopic heart transplantation with the modified anastomosis. Tricuspid regurgitation was graded as follows: 1 = trace, <10%; 2 = mild, 10%-24%; 3 = moderate, 25%-50%; and 4 = severe, >50%. All patients were weaned from inotropic support within 1 week after transplantation with excellent ventricular function, no heart block, and 100% survival at 30 days. The median follow-up time was 173 days (44-358 days). Other median measurements included tricuspid valve regurgitation jet area, 0.30 cm(2) (0-1.90 cm(2)); right atrial area, 15.90 cm(2) (14.47-18.00 cm(2)); atrioventricular diameter, 2.70 cm (2.63-3.09 cm); and tricuspid regurgitation, 1.67% (0-12.42%). Mild regurgitation occurred in 1 recipient; in all others, it was trace. The modified inferior vena caval anastomosis is simple and safe. It eliminates moderate and severe tricuspid valve regurgitation without routine annuloplasty after orthotopic heart transplantation via the bicaval technique.

Effect of Early Intervention With Positive Airway Pressure Therapy for Sleep Disordered Breathing on Six-Month Readmission Rates in Hospitalized Patients With Heart Failure.

Rehospitalization for congestive heart failure (CHF) is high within 6 months of discharge. Sleep disordered breathing (SDB) is common and underdiagnosed condition in patients with CHF. We hypothesized that early recognition and treatment of SDB in hospitalized patients with CHF will reduce hospital readmissions and emergency room visits. Patients admitted for CHF underwent overnight polysomnography within 4 weeks of discharge. Patients diagnosed with SDB were provided therapy with positive airway pressure therapy. Patients were identified as having good compliance if the device use was for a minimum of 4 hours 70% of the time for a minimum of 4 weeks during the first 3 months of therapy. Hospital admissions for 6 months before therapy were compared with readmission within 6 months after therapy in patients with good and poor compliance. A total of 70 patients were diagnosed with SDB after discharge. Of the 70 patients, 37 (53%) were compliant with positive airway pressure therapy. Compliant patients were more likely to be older (64 ± 12 vs 58 ± 11 years) and women (54% vs 33%) and less likely to be patient with diabetes (40% vs 67%) versus noncompliant patients. Although both groups experienced a decrease in total readmissions, compliant patients had a significant reduction (mean ± SE: -1.5 ± 0.2 clinical events vs -0.2 ± 0.3; p <0.0001). In this single-center analysis, identification and treatment of SDB in admitted patients with CHF with SDB is associated with reduced readmissions over 6 months after discharge. Adherence to the treatment was associated with a greater reduction in clinical events.

Photoplethysmographic Signal to Screen Sleep-Disordered Breathing in Hospitalized Heart Failure Patients: Feasibility of a Prospective Clinical Pathway.

OBJECTIVES: The purpose of this study was to evaluate the plethysmographic signal-derived oxygen desaturation index (ODI) as an inpatient screening strategy to identify sleep-disordered breathing (SDB) in patients with congestive heart failure (CHF). BACKGROUND: SDB is highly prevalent among patients hospitalized with CHF but is widely underdiagnosed. We evaluated overnight photoplethysmography as a possible screening strategy for hospitalized patients with CHF. METHODS: Consecutively admitted heart failure patients with high clinical suspicion of SDB and ODI ≥5 were offered outpatient polysomnography (PSG), which was completed within 4 weeks of discharge. PSG was considered positive if the apnea hypoxia index (AHI) was ≥5. A Bland-Altman plot was used to assess agreement between ODI and AHI. Receiver-operator characteristics were determined for ODI ≥5 and AHI ≥5. RESULTS: A screening questionnaire identified 246 of 282 consecutive patients with positive symptoms for SDB. Of these patients, 105 patients were offered further evaluation and 86 had ODI ≥5 (mean ODI 17 ± 17). Among these 86 patients, 68 underwent outpatient PSG within 4 weeks of discharge. PSG showed that 64 (94%) had SDB, with a mean AHI of 28. Inpatient ODI correlated well with PSG-derived AHI. The area under the curve was 0.82 for AHI ≥5. The Bland-Altman plot revealed no major bias. Matthew's correlation coefficient revealed that the optimal cut-off for ODI is 5. CONCLUSIONS: Screening hospitalized patients with heart failure using targeted inpatient ODI identifies a cohort of patients with a high prevalence of SDB. Our screening strategy provides a potentially cost-effective method for early detection and treatment of SDB.

Recurrent orthostatic syncope due to left atrial and left ventricular collapse after a continuous-flow left ventricular assist device implantation.

Left ventricular assist devices (LVADs) have become an established treatment for patients with advanced heart failure as a bridge to transplantation or for permanent support as an alternative to heart transplantation. Continuous-flow LVADs have been shown to improve outcomes, including survival, and reduce device failure compared with pulsatile devices. Although LVADs have been shown to be a good option for patients with end-stage heart failure, unanticipated complications may occur. We describe dynamic left atrial and left ventricular chamber collapse related to postural changes in a patient with a recent continuous-flow LVAD implantation.

Reversible cardiomyopathies.

Cardiomyopathy represents a diverse and heterogenous group of disorders affecting the myocardium and ultimately resulting in cardiac dysfunction. The prevalence of heart failure is high (5 million symptomatic patients in the United States) and increasing. Cardiomyopathy is the leading cause of hospitalization in patients older than 65 years of age, resulting in enormous healthcare expenditure and lost productivity. Ischemic cardiomyopathy accounts for about half of these patients, but in several large clinical trials the prevalence of potentially reversible nonischemic cardiomyopathy is also significant, ranging from 20% to 50%. There is epidemiological evidence that the prognosis of these reversible nonischemic cardiomyopathies is better than ischemic or other nonreversible cardiomyopathies. Early and precise diagnosis of the etiology of heart failure is important for determining prognosis and effective treatments.

Renal dysfunction in heart failure patients: what is the evidence?

Congestive heart failure (CHF) is an increasingly common medical condition and the fastest growing cardiovascular diagnosis in North America. Over one-third of patients with heart failure also have renal insufficiency. It has been shown that renal insufficiency confers worsened outcomes to patients with heart failure. However, a majority of the larger and therapy-defining heart failure medication and device trials exclude patients with advanced renal dysfunction. These studies also infrequently perform subgroup analyses based on the degree of renal dysfunction. The lack of information on heart failure patients who have renal insufficiency likely contributes to their being prescribed mortality and morbidity reducing medications and receiving diagnostic and therapeutic procedures at lower rates than heart failure patients with normal renal function. Inclusion of patients with renal insufficiency in heart failure studies and published guidelines for medication, device, and interventional therapies would likely improve patient outcomes.

Impaired vasoreactivity in end-stage heart failure patients on intravenous inotropic support.

BACKGROUND: Vasoreactivity is known to be impaired in heart failure patients; however, it has not been determined whether standard medical therapy for end-stage heart failure patients (ES-HF) ameliorates this impairment. Therefore, we sought to investigate flow-mediated dilation (FMD) responses in ES-HF with normal or near normal cardiac indices from continuous inotropic support. METHODS AND RESULTS: Vascular ultrasound was used to assess FMD responses to isometric exercise and cuff occlusion in 15 ES-HF patients and 5 control subjects (C). ES-HF patients had significant hyperemic response to maximal exercise (P < .05), which was blunted relative to C (ES-HF; 84 +/- 21 mL/min versus C; 299 +/- 85 mL/min, P < .05). ES-HF patients did not show a significant hyperemic response to submaximal exercise. C had a significant increase in arterial diameter that exceeded ES-HF after both maximal (C; 8 +/- 1% versus. ES-HF; -0.9 +/- 0.86%, P < .05) and submaximal exercise (C; 6 +/- 1% versus ES-HF; 0.57 +/- 1%, P < .05). FMD responses at similar absolute workloads showed that both the mean hyperemic response and the change in arterial diameter were significantly greater in C. After cuff occlusion, the mean hyperemic response for ES-HF was again significantly blunted compared with C (ES-HF; 117 +/- 26% versus C; 352 +/- 86%, P < .05). After cuff occlusion, arterial diameter in C significantly increased in response to hyperemia, whereas ES-HF patients had a paradoxical vasoconstrictive response (C; 10.7 +/- 1.1% versus ES-HF; -5.3 +/- 1.5%, P < .05). CONCLUSION: Peripheral vasoreactivity in response to either maximal exercise, submaximal exercise, or hyperemic stimuli is impaired in ES-HF patients with normal resting cardiac outputs.

Cardiac transplantation across a positive prospective lymphocyte cross-match in sensitized recipients.

BACKGROUND: Although there is an increasing body of evidence for a deleterious effect of mismatched donor HLA antigens on the outcome of human cardiac transplantation, the role of anti-HLA lymphocytotoxic antibodies remains controversial. Thus, their appearance after cardiac transplantation has been associated with poor outcome by some groups; whereas others have reported them to be of no clinical significance. Furthermore, their presence prior to cardiac transplantation has also been the subject of similarly conflicting reports. The deleterious effect of such pre-existing antibodies has been predicted by a positive lymphocyte cross-match (LCM), which, for most patients awaiting renal transplantation and in many requiring a cardiac allograft, leads to cancellation of the operation. The reason for undertaking the current study was to test the hypothesis that the constraints which a positive LCM result impose in preventing renal transplantation may not apply to orthotopic heart transplantation (OHT). PATIENTS AND METHODS: Four sensitized patients underwent OHT across a positive prospective LCM. Three were females, and one of those females also underwent cadaveric renal transplantation at the time of OHT. All four patients received aggressive early post-transplant immunosuppressive therapy, which included plasmapheresis, intravenous immunoglobulin (IVIg), antiproliferative agents (cyclophosphamide, basiliximab) and cytokine down-regulators (calcineurin inhibitors, muromonab-CD3) and anticell antibodies (OKT3, ATG). They also received standard immunosuppressive therapy which included corticosteroids. Complement-dependent cytotoxicity (CDC) was used for the identification of anti-HLA lymphocytotoxic antibodies. Reactivity of the latter against more than 10% of a panel of well-characterized T cells was considered sensitization, and required LCM to be performed prospectively, which test was also performed using the CDC technique. RESULTS: Three of the patients exhibited evidence suggestive of acute or hyperacute rejection in endomyocardial biopsy specimens by postoperative day (POD) 7. Two of the three patients with rejection also exhibited haemodynamic instability (elevated filling pressures and reduced cardiac index) on POD 1, which improved with inotropic support. One patient sustained a cardiac arrest on POD 7, and was successfully resuscitated without sequelae. All patients are now doing well, postoperatively (follow-up: 17-57 months) post-transplant. Two patients have normal left ventricular function and one patient has mild left ventricular dysfunction. Two have no further evidence of sensitization (PRA < 10%). CONCLUSIONS: Although the number of patients in this study is small, the long-term successful outcome of OHT following positive prospective cross-matches suggests that such a test result, in contrast to the restraints it imposes on renal transplantation, may not be a contra-indication to transplantation of the human heart. If OHT proceeds after the LCM is reported positive, aggressive immunotherapy should not only be initiated early, but should also be targeted at humoral-vascular rejection in particular.