Mechanical dyssynchrony in congestive heart failure: diagnostic and therapeutic implications

Myocardial imaging has been successfully applied to the evaluation of patients with heart failure, particularly identifying candidates who are likely to respond to cardiac resynchronization therapy (CRT). Recent studies have shown the benefits of CRT in heart failure patients with depressed ejection fraction (EF) and a narrow QRS complex, albeit in a small number of patients, and without a placebo arm. In addition, few reports have noted the presence of pathophysiologically relevant mechanical dyssynchrony in patients with heart failure and normal EF. Collectively, these data support the need for a better understanding of cardiac function/dysfunction and its treatment in these patient groups.     

Clinical and echocardiographic characteristics of left atrial spontaneous echo contrast in sinus rhythm

OBJECTIVES

In this study we attempt to define the clinical and echocardiographic characteristics of patients with left atrial spontaneous echo contrast (LASEC) in sinus rhythm (NSR).

BACKGROUND

Left atrial spontaneous echo contrast in atrial fibrillation (AF) is associated with increased risk of thromboembolism. Little is known about its significance in NSR.

METHODS

We reviewed reports of 1,288 transesophageal echocardiogram (TEE) studies done with a 5 MHz probe. Patients with swirling LASEC who were in NSR during TEE were analyzed. We compared them with a control group of 45 age matched patients selected to have NSR, left atrium (LA) >4.0 cm but no SEC.

RESULTS

Spontaneous echo contrast in NSR was noted in 24 patients (2%) and formed our study group. All patients with SEC had enlarged LA, mean 5.6 cm ± 0.6 cm. There was a higher prevalence of cerebrovascular accident (CVA) in patients with SEC when compared with controls with no SEC, 83% versus 56%, p = 0.02. Patients with SEC had larger LA, 5.6 versus 4.9 cm, p < 0.0001 and lower mean peak left atrial appendage emptying velocity (LAAEV), 38 versus 56 cm/s, p = 0.001. Thirteen percent of patients with SEC had LA thrombus as compared with none in the control group, p = 0.02. By multivariate analysis, SEC in NSR was found to be associated with CVA, larger LA size and decreased mean LAAEV. Even after adjusting for LA size, patients with SEC had a higher prevalence of CVA than controls, p = 0.03.

CONCLUSIONS

Spontaneous echo contrast in NSR occurs in patients with significantly dilated LA and depressed atrial function. Left atrial thrombus is noted in 13% of such patients despite NSR. Spontaneous echo contrast in NSR is associated with a higher prevalence of CVA. Further, SEC is found to be an independent and more powerful correlate of CVA than reduced LAAEV or atrial size. These data indicate that LASEC in NSR is a prothombotic condition.     

The prognostic value of circulating soluble cell adhesion molecules in patients with chronic congestive heart failure

BACKGROUND: Circulating soluble (s) cell adhesion molecules (CAMs) are elevated in patients with congestive heart failure (CHF) and may play an important role in the pathogenesis of CHF by mediating the cell-cell interactions of the immune response. However, clinical data about the prognostic value of sCAMs are sparse. The purpose of this study is to determine whether various sCAMs can provide prognostic information in patients with CHF. METHODS: We measured circulating levels of three sCAMs (vascular cell adhesion molecule-1, intercellular adhesion molecule-1, and sP-selectin) in 74 patients with symptomatic chronic CHF and left ventricular ejection fraction (LVEF) <50%. We compared these levels with those of a group of 19 age-matched control subjects. Major adverse cardiac events (death, heart transplantation or hospitalization with worsening CHF) during a median follow-up period of 240 days were determined. RESULTS: The concentrations of the three sCAMs in the 74 patients with CHF were significantly associated with one another. Their levels were higher than those of the control subjects and increased with the severity of CHF. Significantly higher sCAM levels were noted in those patients who had major adverse cardiac events during the follow-up period. There were significant negative correlations between LVEF and sCAMs. However, only high levels of sP-selectin were found to be an independent significant predictor of CHF by Cox proportional hazards analysis. CONCLUSIONS: These findings indicate that the levels of these three sCAMs increase with the severity of CHF and are related to clinical outcomes. Among them, high levels of sP-selectin can provide prognostic information independently in patients with CHF.     

Echocardiography in heart failure: applications, utility, and new horizons

Echocardiography is well qualified to meet the growing need for noninvasive imaging in the expanding heart failure (HF) population. The recently-released American College of Cardiology/American Heart Association guidelines for the diagnosis and management of HF labeled echocardiography "the single most useful diagnostic test in the evaluation of patients with HF...," because of its ability to accurately and noninvasively provide measures of ventricular function and assess causes of structural heart disease. It can also detect and define the hemodynamic and morphologic changes in HF over time and might be equivalent to invasive measures in guiding therapy. In this article we will discuss: 1) the clinical uses of echocardiography in HF and their prognostic value; 2) the use of echocardiography to guide treatment in HF patients; and 3) promising future techniques for echocardiographic-based imaging in HF. In addition, we will highlight some of the limitations of echocardiography.     

Patient characteristics associated with care by a cardiologist among adults hospitalized with severe congestive heart failure

OBJECTIVES

The goal of this study was to determine factors associated with receiving cardiologist care among patients with an acute exacerbation of congestive heart failure.

BACKGROUND

Because cardiologist care for acute cardiovascular illness may improve care, barriers to specialty care could impact patient outcomes.

METHODS

We studied 1,298 patients hospitalized with acute exacerbation of congestive heart failure who were cared for by cardiologists or generalist physicians. Using multivariable logistic models we determined factors independently associated with attending cardiologist care.

RESULTS

Patients were less likely to receive care from a cardiologist if they were black (adjusted odds ratio [AOR] 0.53, 95% confidence interval [CI] 0.35, 0.80), had an income of less than $11,000 (AOR 0.65, 95% CI 0.45, 0.93) or were older than 80 years of age (AOR 0.23, 95% CI 0.12, 0.46). Patients were more likely to receive cardiologist care if they had college level education (AOR 1.89, 95% CI 1.02, 3.51), a history of myocardial infarction (AOR 1.59, 95% CI 1.17, 2.16), a serum sodium less than 133 on admission (AOR 1.96, 95% CI 1.30, 2.95) or a systolic blood pressure less than 90 on admission (AOR 1.97, 95% CI 1.20, 3.24). Patients who stated a desire for life extending care were also more likely to receive care from a cardiologist (AOR 1.40, 95% CI 1.04, 1.90).

CONCLUSIONS

After adjusting for severity of illness and patient preferences for care, patient sociodemographic factors were strongly associated with receiving care from a cardiologist. Future investigations are required to determine whether these associations represent unmeasured preferences for care or inequities in our health care system.     

Sudden death in mitral regurgitation due to flail leaflet

OBJECTIVES

We sought to assess the incidence and determinants of sudden death (SUD) in mitral regurgitation due to flail leaflet (MR-FL).

BACKGROUND

Sudden death is a catastrophic complication of MR-FL. Its incidence and predictability are undefined.

METHODS

The occurrence of SUD was analyzed in 348 patients (age 67 ± 12 years) with MR-FL diagnosed echocardiographically from 1980 through 1994.

RESULTS

During a mean follow-up of 48 ± 41 months, 99 deaths occurred under medical treatment. Sudden death occurred in 25 patients, three of whom were resuscitated. The sudden death rates at five and 10 years were 8.6 ± 2% and 18.8 ± 4%, respectively, and the linearized rate was 1.8% per year. By multivariate analysis, the independent baseline predictors of SUD were New York Heart Association (NYHA) functional class (p = 0.006), ejection fraction (p = 0.0001) and atrial fibrillation (p = 0.059). The yearly linearized rate of sudden death was 1% in patients in functional class I, 3.1% in class II and 7.8% in classes III and IV. However, of 25 patients who had SUD, at baseline, 10 (40%) were in functional class I, 9 (36%) were in class II and only 6 (24%) in class III or IV. In five patients (20%), no evidence of risk factors developed until SUD. In patients with an ejection fraction ≥60% and sinus rhythm, the linearized rate of SUD was not different in functional classes I and II (0.8% per year). Surgical correction of MR (n = 186) was independently associated with a reduced incidence of SUD (adjusted hazard ratio [95% confidence interval] 0.29 [0.11 to 0.72], p = 0.007).

CONCLUSIONS

Sudden death is relatively common in patients with MR-FL who are conservatively managed. Patients with severe symptoms, atrial fibrillation and reduced systolic function are at higher risk, but notable rates of SUD have been observed without these risk factors. Correction of MR appears to be associated with a reduced incidence of SUD, warranting early consideration of surgical repair.     

Exercise in valvular heart disease: risks and benefits

Valvular heart disease (VHD) carries documented risks for active individuals. At the same time, many individuals with intermediate degrees of valve disease can safely exercise and even participate in competitive athletics. Unfortunately for clinicians caring for these patients, data are scarce. Understanding the pathophysiology and natural history of VHD is key to applying consensus guidelines and making recommendations to individual patients. Careful physical examination and appropriate imaging studies will identify patients at risk; most will require serial evaluation but can exercise and participate in sports as desired. When symptoms develop, prompt treatment of severe, symptomatic disease and intensive cardiac rehabilitation as well as continued surveillance after surgical treatment will maximize the functional ability of active individuals with VHD.     

The duration of beta‐blocker therapy and outcomes in patients without heart failure or left ventricular systolic dysfunction after acute myocardial infarction: A multicenter prospective cohort study

BackgroundThe duration of beta‐blocker therapy in patients without heart failure (HF) or left ventricular systolic dysfunction after acute myocardial infarction (AMI) is unclear.HypothesisContinuous beta‐blocker therapy is associated with an improved prognosis.MethodsThis is a prospective, multicenter, cohort study. One thousand four hundred and eighty‐three patients eventually met the inclusion criteria. The study groups included the continuous beta‐blocker therapy group (lasted ≥6 months) and the discontinuous beta‐blocker therapy group (consisting of the no‐beta‐blocker therapy group and the beta‐blocker therapy <6 months group). The inverse probability treatment weighting was used to control confounding factors. The study tried to learn the role of continuous beta‐blocker therapy on outcomes. The median duration of follow‐up was 13.0 months. The primary outcomes were cardiac death and major adverse cardiovascular events (MACE). The secondary outcomes were all‐cause death, stroke, unstable angina, rehospitalization for HF, and recurrent myocardial infarction (MI).ResultsCompared with discontinuous beta‐blocker therapy, continuous beta‐blocker therapy was associated with a reduced risk of unstable angina, recurrent MI, and MACE (hazard ratio [HR]: 0.51; 95% CI: 0.32–0.82; p = 0.006); but this association was not available for cardiac death (HR: 0.57; 95% CI: 0.24–1.36; p = 0.206). When compared to the subgroups of no‐beta‐blocker therapy and beta‐blocker therapy <6 months, respectively, continuous beta‐blocker therapy was still observed to be associated with a reduced risk of unstable angina, recurrent MI, and MACE.ConclusionsContinuous beta‐blocker therapy was associated with a reduced risk of unstable angina or recurrent MI or MACE in patients without HF or left ventricular systolic dysfunction after AMI.