Invasive and non-invasive determinants of pulmonary hypertension in patients with chronic heart failure

Role of CT attenuation correction gated SPECT MPI in prediction of pulmonary hypertension

OBJECTIVE

To elucidate the value of gated SPECT-MPI using CT attenuation correction (AC) for prediction of pulmonary hypertension (PHT) in coronary patients by estimation of reliability of non-contrast CT in measurement of main pulmonary artery diameter (MPAd) as well as by assessment of potential predictive role of gated parameters as beneficial accessory findings.

BACKGROUND

Contrast-enhanced CT is known as an accurate tool for assessment of MPAd to predict PHT. [1] The low-dose non-contrast CT which is used for AC in MPI study, however, has an unclear value in precise vascular diameter measurement; it is also uncertain whether gated parameters could help to predict PHT.

METHODS AND PATIENTS

A total of 207 patients, who had a transthoracic echocardiography and MPI with an interval of maximum one month, underwent this retrospective study. PHT was defined as a RVSP ≥36 mmHg by echocardiography; peak tricuspid regurgitation velocity (PTRV) was also calculated to use as a criterion for PHT. Of all subjects, 120 had RVSP ≥ 36 and 87 showed RVSP < 36; there also were 191 and 16 patients with PTRV ≤ 3.4 m/s and >3.4 m/s, respectively. Comparison was made unconnectedly between each group regarding the echocardiography results with the MPI parameters, with and without CT-AC, including MPAd derived from CT as well as RV/LV uptake ratio, shape index and septal wall motion and thickening scores to define the best indicators of PHT.

RESULTS

There was a significant association between established benchmark of PHT in echocardiography (RVSP), with MPAd derived from non-contrast CT as well as with LV shape index from gated study and RV/LV uptake ratio acquired from non-AC SPECT-MPI. Also, stress and rest RV/LV uptake ratio, MPAd, LV end-systolic and LV end-diastolic shape indexes are significantly higher in patients with RVSP ≥ 36 mmHg compare to patients with RVSP < 36 mmHg.

CONCLUSIONS

Gated-SPECT-MPI using CT-AC can predict PHT by reliable estimation of MPAd as well as by defining RV/LV uptake ratio and shape index, providing an added clinical value for this invaluable modality in cardiac patients.

Pulmonary vascular disease in the setting of heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) is defined as clinical features of heart failure, ideally with biomarker evidence such as elevated plasma natriuretic peptide levels, in the setting of an ejection fraction (EF) greater than 50% and imaging evidence of diastolic left ventricular dysfunction [1,2]. In the absence of cardiac imaging or invasive hemodynamics, this is a clinical syndrome that is often indistinguishable from heart failure with reduced ejection fraction (HFrEF). HFpEF and HFrEF present with a cadre of comparable signs and symptoms including jugular venous distention, pulmonary rales on auscultation, breathlessness, orthopnea, exercise intolerance, exertional dyspnea, fatigue and peripheral edema. HFpEF accounts for at least half of all diagnoses of heart failure [1,2]. Pulmonary hypertension (PH) is a common complication of HFpEF that is linked to worse disease morbidity and mortality. In fact, mortality has been linked to increases in the intrinsic pulmonary vascular resistance in the setting of increased left ventricular end diastolic pressure, characterized hemodynamically by rises in the transpulmonary pressure gradient, pulmonary vascular resistance or diastolic pressure gradient. Despite being the most common form of PH, there are no approved therapies for the treatment of PH secondary to HFpEF. This review will summarize the hemodynamic classifications of PH in the setting of HFpEF, mechanisms of disease, the potential contribution of pulmonary vascular disease to poor outcomes in patients with HFpEF, and new approaches to therapy.

Pulmonary Hypertension in Central Australia: A Community-Based Cohort Study

BACKGROUND

The burden of pulmonary hypertension (PHT) in Central Australia has not been previously studied. Our aim is to characterise the prevalence, clinical classification, and long-term survival of individuals with PHT in Central Australia.

METHODS

A community-based cohort study of all individuals diagnosed with PHT in Central Australia between 2005 and 2016 was undertaken. We estimated PHT prevalence using population data, describe clinical PHT classification, and characterised long-term survival using Kaplan-Meier approaches.

RESULTS

A total of 183 patients were identified (mean age 52±16years, 63% female). Of these individuals, 149 (81.4%) were of Aboriginal and Torres Strait Islander (ATSI) descent. The prevalence per 100,000 of any PHT was significantly higher In ATSI (723 [95% CI 608-839] compared to non-ATSI individuals (126 [95% CI 84-168], p<0.001). Furthermore, ATSI individuals were diagnosed at younger ages compared to non-ATSI individuals (49±15 vs 64±16years, p<0.001). Median estimated pulmonary artery systolic pressure (ePASP) was higher in patients with pulmonary arterial hypertension (PAH) compared to other causes (62 [IQR 54-69] vs 50 [IQR 44-58] mmHg, p<0.01). The median survival rate from diagnosis was 9 years (IQR 7.2-13.2). Age and ePASP were significant predictors of mortality (HR 1.05 [95% CI 1.02-1.07] and HR 1.56 [95% 1.00-2.42] respectively).

CONCLUSIONS

In this community based study, we found a high burden of PHT in Central Australia. The prevalence of PHT is greater in ATSI individuals and is diagnosed at younger ages compared to non-ATSI individuals. Together with other cardiovascular diseases, PHT may be in-part contributing to the gap in life expectancy between ATSI and non-ATSI individuals.

Left atrial dysfunction as a determinant of pulmonary hypertension in patients with severe aortic stenosis and preserved left ventricular ejection fraction

In patients with severe aortic stenosis (AS), the presence of pulmonary hypertension (PH) has been linked to a poor prognosis. We aimed to assess the main determinants of PH in patients with severe AS and preserved left ventricular ejection fraction (LVEF). We prospectively enrolled 108 consecutive patients with isolated severe AS (indexed aortic valve area <0.6 cm²/m²) and LVEF >50%, in sinus rhythm. Left atrial (LA) function was assessed using longitudinal deformation parameters (by speckle tracking echocardiography). PH (defined as systolic pulmonary artery pressure >40 mmHg) was present in 20 patients. Patients with severe AS and PH were older (p = 0.05), had higher BNP values (p = 0.05) and a greater degree of LV diastolic dysfunction: higher E/e' and E/A ratios and lower EDT values (p < 0.03 for all) compared to patients without PH. There were no differences between groups regarding AS severity and LV systolic function parameters. Patients with PH had a more impaired LA function: lower septal and lateral late diastolic peak velocity a' (p < 0.001 and p = 0.04 respectively) and lower LA peak longitudinal strain and strain rate parameters (p ≤ 0.005 for all). In multivariable analysis, LA late diastolic longitudinal strain rate was the only independent correlate of PH in our patients (p = 0.04). Patients with isolated severe AS, preserved LVEF and PH had larger LA volumes, a more impaired LA function, and higher LV filling pressures compared to those without PH. LA booster pump function, reflected by late diastolic longitudinal strain rate, emerged as an independent correlate of PH in these patients.

Evolving Concepts of Pulmonary Hypertension Secondary to Left Heart Disease

Pulmonary hypertension associated with left heart disease is the most common form of pulmonary hypertension. Although its pathophysiology remains incompletely understood, it is now well recognized that the presence of pulmonary hypertension is associated with a worse prognosis. Right ventricular failure has independent and additive prognostic value over pulmonary hypertension for adverse outcomes in left heart disease. Recently, several new terminologies have been introduced to better define and characterize the nature and severity of pulmonary hypertension. Several new treatment options including the use of pulmonary arterial hypertension specific therapies are being considered, but there is lack of evidence. Here, we review the recent advances in this field and summarize the diagnostic and therapeutic modalities of use in the management of pulmonary hypertension associated with left heart disease.

Prognostic Value of Right Ventricular Tei Index in Dogs with Myxomatous Mitral Valvular Heart Disease

BACKGROUND

The right ventricular (RV) Tei index (TX) has a significant correlation with the severity of pulmonary hypertension. However, the role of RV dysfunction in dogs with myxomatous mitral valvular heart disease (MMVD) has not been addressed.

OBJECTIVES

To investigate the correlation between right ventricular Tei-index (RVTX) and the prognosis for dogs with MMVD.

ANIMALS

Thirty client-owned dogs with MMVD.

METHODS

Clinical cohort study. Dogs were divided into two groups on the basis of the onset of cardiac-related death within 1 year of the first echocardiographic examination. Physical examination and echocardiographic variables were compared between the groups. Receiver operating characteristic (ROC) curves and multivariate logistic analysis were used to assess the comparative accuracy when identifying dogs with cardiac-related death.

RESULTS

The highest accuracy was obtained for RVTX with an area under the ROC curve (AUC) of 0.95 (95% confidence interval [CI] 0.81-0.99) followed by the left atrial to aortic root ratio with an AUC of 0.91 (95% CI 0.74-0.98), peak early diastolic mitral inflow velocity with an AUC of 0.84 (95% CI 0.64-0.94), and Doppler estimates of systolic pulmonary artery pressure with an AUC of 0.84 (95% CI 0.61-0.95). According to the multivariate logistic regression analysis, RVTX was the only independent correlate of cardiac-related death within 1 year.

CONCLUSIONS AND CLINICAL IMPORTANCE

Right ventricular Tei-index has a strong correlation with the prognosis for dogs with MMVD. The most significant independent predictor of death was RVTX in this study.

Early improvement of functional mitral regurgitation in patients with idiopathic dilated cardiomyopathy

The aim of the study was to assess the clinical and prognostic impact of early functional mitral regurgitation (FMR) improvement on the outcome of patients with idiopathic dilated cardiomyopathy (IDC). The prevalence and prognostic role of FMR improvement, particularly at early follow-up, in patients with IDC are still unclear. From 1988 to 2009, we enrolled 470 patients with IDC with available FMR data at baseline and after 6 ± 2 months. According to the evolution of FMR, patients were classified into 3 groups: stable absent-mild FMR, early FMR improvement (downgrading from moderate-severe to absent-mild), and persistence/early development of moderate-severe FMR. At baseline, 177 of 470 patients (38%) had moderate-severe FMR. Patients with early FMR improvement had significantly better survival rate-free from heart transplant with respect to those with persistence/early development of moderate-severe FMR (93%, 81%, and 66% vs 91%, 64%, and 52% at 1, 6, and 12 years, respectively; p = 0.044). At 6-month follow-up multivariate analysis, FMR improvement was associated with better prognosis (hazard ratio 0.78, 95% confidence interval [CI] 0.64 to 0.96, p = 0.02); the other independent predictors were male gender, heart failure duration, and early re-evaluation of the New York Heart Association class and left ventricle systolic function. This model provided more accurate risk stratification compared with the baseline model (Net Reclassification Index 80% at 12 months and 41% at 72 months). In conclusion, in a large cohort of patients with IDC receiving optimal medical treatment, early improvement of FMR was frequent (53%) and emerged as a favorable independent prognostic factor with an incremental short- and long-term power compared with the baseline evaluation.

Pulmonary artery diastolic pressure gradient as an indicator of severity of illness in patients with pulmonary hypertension related to left-sided heart disease

INTRODUCTION

Pulmonary hypertension (PH) due to left-sided heart disease (Group 2 PH) is most commonly due to passive backward transmission of elevated left-sided heart pressures. A subgroup of these patients develop pulmonary artery remodeling, resulting in systolic and mean pulmonary artery pressures that are 'reactive' or 'out of proportion' to the elevated left-sided heart pressures. These patients have historically been identified by a transpulmonary gradient (TPG) > 12 mmHg. However, since diastolic pulmonary artery pressures are less susceptible to changes in pulmonary blood flow, a diastolic pulmonary gradient (DPG) ⩾ 7 mmHg may be a superior indicator of worse clinical function and prognosis.

METHODS

Based on measurements from a right-heart catheterization (RHC) database (Baylor College of Medicine, Houston, TX, USA), comparisons of several clinical parameters were made among three Group 2 PH patients: normal TPG and DPG (Group 2A), elevated TPG and normal DPG (Group 2B), and elevated TPG and DPG (Group 2C).

RESULTS

Among 173 RHCs, 39 were found to have Group 2 PH. Among these 39 cases, 10 (32%), 13 (32%), and 16 (36%) cases were categorized into Groups 2A, 2B, and 2C, respectively. Group 2C patients had significantly worse 6-min walk distance (308 ± 69 m) than Group 2A (425 ± 81 m) and Group 2B (350 ± 103 m) (p = 0.038). There was no significant difference in cardiac output, cardiac index, and right atrial pressure among the three subgroups.

DISCUSSION

Among patients with Group 2 PH, elevated DPG proved to be a more specific indicator of worse functional status than the historically used TPG. International guidelines and protocols for performing RHC for the assessment and diagnosis of PH should include the measurement of DPG.

Pre-capillary pulmonary hypertension and right ventricular dilation predict clinical outcome in cardiac resynchronization therapy

OBJECTIVES

This study examined the prognostic significance of pre- and post-capillary components of pulmonary hypertension (PH) in patients receiving cardiac resynchronization therapy (CRT).

BACKGROUND

PH is common in patients with left ventricular systolic dysfunction (LVSD) receiving CRT. The impact of PH subtype on clinical outcome in CRT is unknown.

METHODS

The study population consisted of 101 patients (average age 66 ± 13 years, left ventricular ejection fraction 0.23 ± 0.07, and New York Heart Association functional class 3.2 ± 0.4) who underwent right heart catheterization in the 6 months before CRT. PH was defined as a mean pulmonary artery pressure ≥25 mm Hg; a significant pre-capillary contribution to elevated mean pulmonary artery pressure was defined as a transpulmonary gradient (TPG) ≥12 mm Hg. Clinical endpoints were assessed at 2 years and included all-cause mortality and a composite of death, left ventricular assist device, or cardiac transplantation.

RESULTS

Patients with TPG ≥12 mm Hg were more likely to experience all-cause mortality (hazard ratio [HR]: 3.2; 95% confidence interval [CI]: 1.3 to 7.4; p = 0.009) and the composite outcome (HR: 3.0; 95% CI: 1.4 to 6.3; p = 0.004) compared with patients with TPG <12 mm Hg. After multivariate adjustment for hemodynamic, clinical, and echocardiographic variables, only TPG ≥12 mm Hg and baseline right ventricular (RV) dilation (RV end-diastolic dimension >42 mm) were associated with the composite clinical outcome (p = 0.05 and p = 0.04, respectively).

CONCLUSIONS

High TPG PH and RV dilation are independent predictors of adverse outcomes in patients with LVSD who are receiving CRT. RV pulmonary vascular dysfunction may be a therapeutic target in select patients receiving CRT.

Quantitative Doppler-Echocardiographic Imaging and Clinical Outcomes With Left Ventricular Systolic Dysfunction

Background—

Doppler-echocardiography provides quantitative imaging of systolic and diastolic left ventricular (LV) function, functional mitral regurgitation (FMR), and pulmonary hypertension (PH) in patients with LV systolic dysfunction. Whether PH is linked to survival independently of LV features and FMR in symptomatic and asymptomatic patients is unknown.

Methods and Results—

Patients with LV ejection fraction ≤40% and quantitative Doppler-echocardiography assessment of FMR and PH were studied. Patients were frequency matched for those with Doppler-echocardiography estimated pulmonary systolic pressure ≥45 mm Hg (n=692) and those without PH (n=692; pulmonary systolic pressure, <45 mm Hg) for age, sex, LV ejection fraction, and quantified FMR severity and analyzed for long-term survival after diagnosis. During follow-up (median, 8.9 years), 885 deaths (63.5%) occurred, with PH being associated with higher 5-year mortality: 51±2% versus 37±2%, P <0.001. In multivariate analysis, PH demonstrated increased mortality risk independent of age, sex, severity of diastolic and systolic LV dysfunction, FMR, comorbidities, and symptom (hazard ratio, 1.34; 95% confidence limit, 1.17–1.53; P <0.001). Subgroup analysis, stratified by symptoms, degree of FMR, and severity of LV dysfunction, demonstrated that PH was associated with excess mortality in all subgroups.

Conclusions—

In this large cohort of patients with LV systolic dysfunction, in whom FMR and LV characteristics were quantified and matched between those with and without PH, the presence of PH was an independent factor for excess mortality and not a surrogate for the severity of LV systolic dysfunction or FMR. In asymptomatic or symptomatic patients with or without FMR, PH is a critical marker for poor outcomes.

Right ventricular systolic function in organic mitral regurgitation: impact of biventricular impairment

BACKGROUND

To assess the prevalence, determinants, and prognosis value of right ventricular (RV) ejection fraction (EF) impairment in organic mitral regurgitation.

METHODS AND RESULTS

Two hundred eight patients (62±12 years, 138 males) with chronic organic mitral regurgitation referred to surgery underwent an echocardiography and biventricular radionuclide angiography with regional function assessment. Mean RV EF was 40.4±10.2%, ranging from 10% to 65%. RV EF was severely impaired (≤35%) in 63 patients (30%), and biventricular impairment (left ventricular EF<60% and RV EF≤35%) was found in 34 patients (16%). Pathophysiologic correlates of RV EF were left ventricular septal function (β=0.42, P<0.0001), left ventricular end-diastolic diameter index (β=-0.22, P=0.002), and pulmonary artery systolic pressure (β=-0.14, P=0.047). Mitral effective regurgitant orifice size (n=84) influenced RV EF (β=-0.28, P=0.012). In 68 patients examined after surgery, RV EF increased strongly (27.5±4.3-37.9±7.3, P<0.0001) in patients with depressed RV EF, whereas it did not change in others (P=0.91). RV EF ≤35% impaired 10-year cardiovascular survival (71.6±8.4% versus 89.8±3.7%, P=0.037). Biventricular impairment dramatically reduced 10-year cardiovascular survival (51.9±15.3% versus 90.3±3.2%, P<0.0001; hazard ratio, 5.2; P<0.0001) even after adjustment for known predictors (hazard ratio, 4.6; P=0.004). Biventricular impairment reduced also 10-year overall survival (34.8±13.0% versus 72.6±4.5%, P=0.003; hazard ratio, 2.5; P=0.005) even after adjustment for known predictors (P=0.048).

CONCLUSIONS

In patients with organic mitral regurgitation referred to surgery, RV function impairment is frequent (30%) and depends weakly on pulmonary artery systolic pressure but mainly on left ventricular remodeling and septal function. RV function is a predictor of postoperative cardiovascular survival, whereas biventricular impairment is a powerful predictor of both cardiovascular and overall survival.

Classification of pulmonary hypertension

Pulmonary hypertension (PH) can develop in association with many different diseases and risk factors, and its presence is nearly always associated with reduced survival. The prognosis and management of PH is largely dependent upon its underlying etiology and severity of disease. The combination of clinical and hemodynamic classifications of PH provides a framework for the diagnostic evaluation of PH to establish a final clinical diagnosis that guides therapy. As our understanding of the different pathologic mechanisms that underlie the syndrome of PH evolves, so too will the classification and treatment of PH.

Left atrial function in cats with left-sided cardiac disease and pleural effusion or pulmonary edema

BACKGROUND

Congestive heart failure (CHF) in cats with left-sided heart disease is sometimes manifest as pleural effusion, in other cases as pulmonary edema.

HYPOTHESIS

Those cats with pleural effusion have more severe left atrial (LA) dysfunction than cats with pulmonary edema.

ANIMALS

30 healthy cats, 22 cats with pleural effusion, and 12 cats with pulmonary edema. All cats were client owned.

METHODS

Retrospective study. Measurements of LA size and function were made using commercial software on archived echocardiograms. Cases were identified through searches of medical records and of archived echocardiograms for cats with these conditions.

RESULTS

There was no difference (P = .3) in LA size between cats with pleural effusion and cats with pulmonary edema. Cats with pleural effusion had poorer (P = .04) LA active emptying and increased (P = .006) right ventricular (RV) diameter when compared with cats with pulmonary edema and healthy cats. Cats that exhibited LA active emptying of <7.9%, total emptying of <13.6% (diameter) or <19.4% (area), or RV diameter of >3.6 mm were significantly (P < .001) more likely to manifest pleural effusion.

CONCLUSIONS AND CLINICAL IMPORTANCE

Poorer LA function and increased RV dimensions are associated with pleural effusion in cats with left-sided heart disease.

Predictors of right ventricular systolic dysfunction in compensated and decompensated heart failure

Current understanding of the mechanisms of right ventricular (RV) systolic dysfunction in heart failure (HF) is limited. The authors analyzed a limited access dataset from the Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness (ESCAPE) provided by the National Heart, Lung, and Blood Institute (NHLBI). RV systolic function was measured by echocardiography at baseline and at 3-month follow-up using fractional area change. Univariate and multivariate analysis was performed with linear regression. Of 433 patients enrolled in the ESCAPE trial, 190 had RV systolic function measured at baseline (decompensated HF) and 147 had it measured at 3-month follow-up. On both occasions, parameters of congestion were associated with RV systolic function. Interestingly, lower hematocrit level was also associated with better RV systolic function. In multivariate analysis, only wedge pressure remained a statistically significant predictor of RV dysfunction. In summary, cardiac diastolic pressures and corresponding echocardiographic parameters, as well as hematocrit level, predicted RV systolic function in both compensated and decompensated systolic HF.

Pulmonary pressures and death in heart failure: a community study

OBJECTIVES

The purpose of this study was to determine among community patients with heart failure (HF) whether pulmonary artery systolic pressure (PASP) assessed by Doppler echocardiography was associated with death and improved risk prediction over established factors, using the integrated discrimination improvement and net reclassification improvement.

BACKGROUND

Although several studies have focused on idiopathic pulmonary arterial hypertension, less is known about pulmonary hypertension among patients with HF, particularly about its prognostic value in the community.

METHODS

Between 2003 and 2010, Olmsted County residents with HF prospectively underwent assessment of ejection fraction, diastolic function, and PASP by Doppler echocardiography.

RESULTS

PASP was recorded in 1,049 of 1,153 patients (mean age 76 ± 13; 51% women). Median PASP was 48 mm Hg (25th to 75th percentile: 37.0 to 58.0). There were 489 deaths after a follow-up of 2.7 ± 1.9 years. There was a strong positive graded association between PASP and mortality. Increasing PASP was associated with an increased risk of death (hazard ratio [HR]: 1.45, 95% confidence interval [CI]: 1.13 to 1.85 for tertile 2; HR: 2.07, 95% CI: 1.62 to 2.64 for tertile 3 vs. tertile 1), independently of age, sex, comorbidities, ejection fraction, and diastolic function. Adding PASP to models including these clinical characteristics resulted in an increase in the c-statistic from 0.704 to 0.742 (p = 0.007), an integrated discrimination improvement gain of 4.2% (p < 0.001), and a net reclassification improvement of 14.1% (p = 0.002), indicating that PASP improved prediction of death over traditional prognostic factors. All results were similar for cardiovascular death.

CONCLUSIONS

Among community patients with HF, PASP strongly predicts death and provides incremental and clinically relevant prognostic information independently of known predictors of outcomes.

Pulmonary hypertension associated with left heart disease: characteristics, emerging concepts, and treatment strategies

Left heart disease (LHD) represents the most common causes of pulmonary hypertension (PH). Whether caused by systolic or diastolic dysfunction or valvular heart disease, a hallmark of PH associated with LHD is elevated left atrial pressure. In all cases, the increase in left atrial pressure causes a passive increase in pulmonary pressure. In some patients, a superimposed active component caused by pulmonary arterial vasoconstriction and vascular remodeling may lead to a further increase in pulmonary arterial pressure. When present, PH is associated with a worse prognosis in patients with LHD. In addition to local abnormalities in nitric oxide and endothelin production, gene modifiers such as serotonin polymorphisms may be associated with the pathogenesis of PH in LHD. Optimizing heart failure regimens and corrective valve surgery represent the cornerstone of the treatment of PH in LHD. Recent studies suggest that sildenafil, a phosphodiesterase-5 inhibitor, is a promising agent in the treatment of PH in LHD. Unloading the left ventricle with circulatory support may also reverse severe PH in patients with end-stage heart failure allowing candidacy to heart transplantation.

Differentiating pulmonary arterial and pulmonary venous hypertension and the implications for therapy

Pulmonary arterial and pulmonary venous hypertension develop from distinctly different etiologies. Pulmonary arterial hypertension (PAH), or Group 1 pulmonary hypertension (PH), is a precapillary PH that arises idiopathically or as the result of a divergent array of causes, including connective tissue disease. Pulmonary venous hypertension (PVH), or Group 2 PH, primarily manifests as a postcapillary PH in the setting of left heart failure or valvular disease. A subset of PVH patients, however, develop a reactive precapillary component of PH that mimics PAH. These patients can be misdiagnosed as having Group 1 PH by 2-dimensional echocardiography and are sometimes treated as such, which leads to exacerbation of heart failure. Therefore, 2-dimensional or Doppler echocardiography alone cannot be used to differentiate between these two classifications of PH. This highlights the need for right heart catheterization in the clinical assessment and diagnostic work-up of PH. The combination of imaging and invasive hemodynamic assessment by right heart catheterization provides the best diagnostic approach to ensure proper delineation of pulmonary arterial and pulmonary venous hypertension, and in turn leads to appropriate treatment.

Determinants of right ventricular failure in patients admitted with acute left heart failure

Pulmonary hypertension, which may lead to right ventricular (RV) failure, increases with left ventricular (LV) diastolic dysfunction severity. The prevalence and determinants of RV failure were analyzed in 120 patients admitted with acute left heart (LH) failure. Patients were divided into RV failure (n=50) and non-RV failure (n=70) groups. The prevalence of RV failure was found to be 42%. In both groups, two thirds of the patients had isolated LV diastolic dysfunction and the rest had combined LV systolic and diastolic dysfunction. Patients in the RV failure group were characterized by higher LV diastolic grade (2.2 ± 0.6 vs 1.84 ± 0.7; P=.0070), pulmonary artery systolic pressure (PASP; 57.8 ± 15.3 vs 50.14 ± 12.1 mm Hg; P=.0028), right atrial enlargement (92% vs 25.7%; P=.000001), and more-than-moderate tricuspid regurgitation (58% vs 27.1%; P=.0006). RV failure is a frequent finding in patients with advanced LH failure. It is strongly associated with the severity of LV diastolic dysfunction and the severity of PASP.

Relation of left atrial dysfunction to pulmonary artery hypertension in patients with aortic stenosis and left ventricular systolic dysfunction

Pulmonary artery hypertension (PAH) increases mortality in patients with severe aortic stenosis. We hypothesized that left atrial (LA) dysfunction would be related to PAH in patients with severe aortic stenosis complicated by left ventricular (LV) systolic dysfunction. The data from 70 patients with severe aortic stenosis and LV systolic dysfunction were analyzed. From the transmitral flow, the peak early (E) and late (A) diastolic velocities were obtained. From the pulmonary vein flow, the peak S-wave, D-wave, and reversed atrial wave velocities were determined. The right ventricular systolic pressure was measured in 50 patients and averaged 38 +/- 13 mm Hg. Patients with PAH (n = 19) presented with greater LV diameters, E/A ratio, E-wave velocity, LV mass index, reversed atrial wave velocity, and LA volume (p <0.05) and lower S/D ratio and total and active LA emptying fractions (p <0.05). Simple linear regression analysis revealed that the LA volumes and total and active LA emptying fractions displayed the strongest correlations with the right ventricular systolic pressure. Multiple regression analysis revealed that the minimum LA volume (r = 0.61, p = 0.0001) independently correlated with the right ventricular systolic pressure, irrespective of the aortic valve (AV) area or gradient. In patients who underwent an echocardiographic examination >or=1 month after AV replacement, LA function had improved significantly. The degree of improvement was related to the degree of recovery of the LV diastolic function and diameter. In conclusion, in patients with severe aortic stenosis and concomitant LV systolic dysfunction, the LA function parameters displayed the strongest correlations with the right ventricular systolic pressure, irrespective of the AV area or gradient and were impaired in patients with PAH. LA function recovered after AV replacement. Additional studies are warranted to determine the prognostic significance of LA function in this setting.

The right heart and pulmonary circulation (III). The pulmonary circulation in heart failure

Pulmonary hypertension due to left heart disease is a pathophysiological and hemodynamic state which is present in a wide range of clinical conditions that affect left heart structures. Although the pulmonary circulation has traditionally received little attention, it is reasonable to say that today it is a fundamental part of cardiological evaluation. In patients with heart failure, the most important clinical factors are the presence of pulmonary hypertension and right ventricular function. These factors are also essential for determining prognosis and must be taken into account when making some of the most important therapeutic decisions. The pathophysiological process starts passively but later transforms into a reactive process. This latter process, in turn, has one component that can be reversed with vasodilators and another component that is fixed, in which the underlying mechanism is congestive vasculopathy (i.e. essentially medial hypertrophy and pulmonary arterial intimal fibrosis). Currently no specific therapy is available for this type of pulmonary hypertension and treatment is the same as for heart failure itself. The drugs that have been shown to be effective in pulmonary arterial hypertension have generally had a neutral effect in clinical trials. Nevertheless, we are involved in the clinical development of a number of groups of pharmacological compounds that will enable us to make progress in the near future.

Pulmonary hypertension in heart failure

BACKGROUND

Pulmonary hypertension occurs in 60% to 80% of patients with heart failure and is associated with high morbidity and mortality.

METHODS AND RESULTS

Pulmonary artery pressure correlates with increased left ventricular end-diastolic pressure. Therefore, pulmonary hypertension is a common feature of heart failure with preserved as well as reduced systolic function. Pulmonary hypertension is partially reversible with normalization of cardiac filling pressures. Pulmonary vasculature remodeling and vasoconstriction create a second component, which does not reverse immediately, but has been shown to improve with vasoactive drugs and especially with left ventricular assist devices.

CONCLUSION

Many drugs used for idiopathic pulmonary arterial hypertension are being considered as treatment options for heart failure-related pulmonary hypertension. This is of particular significance in the heart transplant population. Randomized clinical trials with interventions targeting heart failure patients with elevated pulmonary artery pressure would be justified.

Pulmonary hypertension in chronic heart failure

The presence of PH in patients who suffer from CHF is common and predicts a poor outcome. However, precise definitions for PH associated with left heart disease, or 'out-of-proportion' PH as well as standardised vasodilator testing protocols are lacking. Moreover, apart from single-centre observations no large-scale trial to date has demonstrated a long-term benefit from pulmonary vasoactive drugs. As a result, there are currently no consensus recommendations for the treatment of PH in the presence of CHF. Off-label use of specific vasodilators in this patient population is discouraged. In a majority of cases, treatment of the underlying left heart disease leads to a decrease in pulmonary pressures. In light of novel agents to treat PH, trials that specifically address 'out-of-proportion' PH in CHF patients are warranted.

Effect of pulmonary hypertension on clinical outcomes in advanced heart failure: analysis of the Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness (ESCAPE) database

BACKGROUND

Pulmonary hypertension has been shown to predict hospitalizations and mortality in patients with heart failure. We aimed to define the prevalence of mixed pulmonary hypertension (MPH; mean pulmonary artery pressure > or = 25 mm Hg, pulmonary capillary wedge pressure >15 mm Hg, and pulmonary vascular resistance > or = 3 Wood units), identify clinical predictors of MPH, and determine whether MPH predicts adverse outcomes in patients hospitalized with severe heart failure.

METHODS

This is a subgroup analysis of patients assigned to pulmonary artery catheter placement in the Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness (ESCAPE) trial. Patients with and without MPH were compared with respect to baseline characteristics and clinical outcomes, including NYHA class, 6-minute walk distance, quality of life, days hospitalized, and 6-month mortality.

RESULTS

Of the 171 patients studied, 80 (47%) had MPH. Older age was the only significant predictor of MPH. MPH patients had lower cardiac index (1.8 +/- 0.5 L/min vs 2.1 +/- 0.5 L/min, P = .001) and higher systemic vascular resistance index (3,179 +/- 1,454 vs 2,550 +/- 927 dynes x s/cm5 x m2, P < .001) compared to those without MPH. Importantly, right ventricular function was relatively preserved (median RVSWI 8.7 gm-m/m2/beat) in MPH patients. There were no significant differences in clinical outcomes between the two groups.

CONCLUSIONS

Mixed pulmonary hypertension is common in patients hospitalized with advanced heart failure and is not associated with adverse short-term clinical outcomes over and above the poor prognosis of ADHF patients without MPH.

Pulmonary hypertension in older adults

Pulmonary hypertension is a frequently encountered problem in older patients. True idiopathic pulmonary arterial hypertension can also be seen and requires careful exclusion in older patients. Institution of therapies must be tempered with an appreciation of individual comorbidities and functional limitations that may affect patients' ability to comply and benefit from the complex treatments available for pulmonary arterial hypertension. This article reviews the existing data on the various forms of pulmonary hypertension presenting in older patients and on appropriate therapy in this challenging population.

Clinical and Hemodynamic Profile of Patients With Advanced Heart Failure Considered for Heart Transplantation

INTRODUCTION

The present study evaluated the clinical and hemodynamic situation of patients with advanced heart failure considered for heart transplantation (HT) to examine the possible impact of prior cardiac disease.

METHODS

We analyzed the pretransplant clinical, echocardiographic, and hemodynamic parameters of 422 consecutive HT patients. Pediatric and heart plus lung transplants were excluded, as were retransplantations. The results were compared by dividing the patients into three groups according to the background heart disease that led to HT: ischemic heart disease (IHD), dilated myocardiopathy (DMC), or valvular disease.

RESULTS

Differences were observed in the baseline characteristics according to the type of heart disease. Male gender, hypertension, and diabetes were more frequent among IHD, while DMC patients tended to be younger. There were no differences in the clinical parameters such as liver and kidney function, in the functional class, or in the need for inotropic treatment over the days prior to transplantation. Likewise, no differences were recorded in the hemodynamic parameters, such as pulmonary pressure, pulmonary vascular resistance, or transpulmonary pressure gradient. As regards the echocardiographic parameters, the patients with DMC showed greater ventricular diameters and lesser ejection fractions for both ventricles.

CONCLUSION

No important differences were recorded in the clinical situation or hemodynamic parameters of patients with advanced heart failure accepted for transplantation, according to the background cardiac disease. This observation could be due to the homogenization by strict transplant waiting list inclusion criteria.

Right ventricular failure in patients with preserved ejection fraction and diastolic dysfunction: an underrecognized clinical entity

It is well recognized that patients with severe left ventricular (LV) systolic dysfunction develop pulmonary venous hypertension or postcapillary pulmonary hypertension, which leads to an increase in pulmonary vascular resistance (PVR) and right ventricular (RV) systolic failure. It is often underrecognized, however, that patients with heart failure with preserved LV ejection fraction and diastolic dysfunction may also develop postcapillary pulmonary hypertension with elevated PVR leading to RV systolic failure. This form of biventricular failure is a result of diastolic failure on the left in patients with preserved LV ejection fraction and systolic failure on the right. At this time, there are no randomized trials or guidelines addressing the management of patients with diastolic heart failure with and without resultant RV failure. The authors review the pathophysiology, clinical presentation, and suggested treatment of this underrecognized clinical entity.

Two simple echo-Doppler measurements can accurately identify pulmonary hypertension in the large majority of patients with chronic heart failure

BACKGROUND

The assessment of pulmonary hypertension in patients with heart failure is of great clinical importance not only for diagnostic purposes but also for prognostication. The present study was undertaken on a consecutive basis with a group of patients with chronic heart failure. Patients were evaluated for their suitability for heart transplantation: (1) to explore the diagnostic accuracy of several echo Doppler parameters of pulmonary hemodynamics in predicting the presence of elevated pulmonary artery pressure (defined as pulmonary artery systolic pressure > or =35 mmHg and mean pulmonary artery pressure >20 mmHg); (2) to assess the diagnostic ability of the same parameters to identify patients with elevated pulmonary vascular resistance; and (3) to evaluate the influence of right ventricular function and degree of tricuspid regurgitation in modifying diagnostic accuracy.

METHODS

Echo Doppler examination and right heart catheterization were performed consecutively within 24 hours in 86 patients. The optimal cut-off value for a series of echo Doppler parameters capable of identifying patients with pulmonary hypertension was obtained by dividing the entire sample into 2 groups; the optimal threshold (highest sensitivity and specificity) of the echo and Doppler parameters used to classify patients with and without pulmonary hypertension was determined in 67% of cases by means of the receiver operating characteristic (ROC) curve: this was the testing sample. The proportion of cases classified correctly according to the selected cut-off was computed. The remaining 33% of cases represented the validation sample: sensitivity, specificity and predictive values (and their 95% confidence intervals [CIs]) for identifying pulmonary hypertension were calculated from the proposed cut-offs in this second sample. Finally, the overall performance of the echo Doppler parameters was assessed over the whole sample by considering the extent of the area under the ROC curve (A-ROC) and its 95% CI, for the dichotomic measurement.

RESULTS

On right heart catheterization, a pulmonary artery systolic (PAPs) pressure > or =35 mmHg plus a mean pressure (mean PAP) >20 mmHg was documented in 49 of 86 cases (57%), for whom mean values were 56 +/- 17 and 38 +/- 11 mmHg, respectively. The proportion of cases identified correctly as having pulmonary hypertension was highest for PAPs (88%) and mean PAP (85%) in addition to acceleration time of pulmonary artery systolic flow (ACT) (79%) and pulmonary artery diastolic pressure obtained utilizing the early phase of the tricuspid regurgitation spectral flow (PAPd/TR) (75%). PAPd/TR performed better in the validating sample in terms of diagnostic ability, with high sensitivity and specificity (100% and 60%) and positive and negative predictive values (PPV 80%, NPV 100%). PAPs, mean PAP, ACT and PAPd/TR confirmed their prevailing diagnostic ability (A-ROC from 0.74 to 0.86) in identifying pulmonary hypertension with fair to high feasibility (67% to 91%) and an odds ratio (OR) indicative of strong association. ACT and PAPd/TR, the 2 parameters with the highest feasibility, allowed us to identify 46 of 49 (94%) hypertensive cases. The same parameters did not perform well in identifying patients with increased vascular resistance, with A-ROC ranging from 0.55 to 0.69. Heterogeneity of effect, due to right ventricular function or tricuspid regurgitation degree, could not be demonstrated in the ability of the echo Doppler measurements to identify pulmonary hypertension.

CONCLUSIONS

ACT, PAPd/TR, PAPs and mean PAP have been shown to accurately classify patients with chronic heart failure with or without pulmonary hypertension. In particular, ACT and PAPd/TR alone allowed reliable and accurate definition of pulmonary hypertension in 94% of patients, regardless of right ventricular function or degree of tricuspid regurgitation. Non-invasive pulmonary pressure assessment by the referred method might be useful in the evaluation of heart transplant candidates.

Usefulness of atrial size inequality as an indicator of abnormal left ventricular filling

Although pulsed Doppler echocardiography estimates current left ventricular (LV) filling, left atrial (LA) size reflects LV filling and pressure over time. However, the wide normal LA size range may blunt this diagnostic tool. Our objective was to compare the intraindividual atrial area difference (LA--right atrial [RA] area) and absolute LA area in their detection of a LA enlargement with respect to the degree of current LV filling impairment. We examined patients with acute coronary syndromes in sinus rhythm and without valvular disease (n = 154), and age- and gender-matched healthy controls (n=50) with echocardiography, applying pulsed Doppler international recommendations to group the patients according to the LV filling pattern: 0, normal; 1, delayed relaxation; 2, an isolated abnormal mitral pulmonary venous A-wave duration difference; 3, pseudonormal; and 4, restrictive. The LA and RA areas were measured in the 4-chamber view. Control values defined the normal range of: absolute LA area, LA area adjusted for body height, and LA-RA area. These areas indicated a LA enlargement in: (1) controls, 2%, 2%, and 4%, respectively; (2) patients with LV filling graded as normal/mildly impaired (groups 0 and 1), 15%, 17%, and 46%, respectively; moderately impaired (group 2), 26%, 29%, and 52%, respectively; and severely impaired (group 3 and 4), 42%, 38%, and 54%, respectively. Unequally sized atria appear to detect LA enlargement sensitively, especially when Doppler evidence of LV filling pathology is sparse. Clinically, with no obvious current cause for LA enlargement, a diagnosed "atrial size inequality" may still indicate a history of such causes.

Pathogenesis of Ascites in Broilers Raised at Low Altitude: Aetiological Considerations Based on Echocardiographic Findings

This study reports novel insight into the aetiology of pulmonary hypertension and ascites in broiler chickens. The scope of measurements was focused on anatomical and functional parameters, and blood flow patterns in leghorns (resistant to ascites), fast-growing broilers (susceptible to ascites), broilers developing ascites, and ascitic broilers evaluated in vivo using echocardiography, and further examined in the context of postmortem findings. Both, in vivo observed features and postmortem findings, showed clear differences between broilers and leghorns, and between normal and ascitic broilers. Abnormalities in the heart chamber geometry and blood flow patterns were detected upon echocardiographic examination in all ascitic broilers. Right and left atrio-ventricular (AV) valve regurgitation were common findings in ascitic broilers and some apparently normal broilers, with left AV valve insufficiency being a predominant feature with respect to degree and frequency of occurrence. Blood flow disturbances were not detected in leghorns. Left ventricular fractional shortening (functional parameter) was considerably reduced (P < 0.01) in ascitic birds (mean: 21.7 +/- 2.0 SE) in comparison with normal broilers (mean: 39.1 +/- 3.6 SE), or leghorns (mean: 43.3 +/- 2.4 SE). The presented findings indicate that pathological and functional changes in the left ventricle and atrium play a significant role in the pathogenesis of ascites in broilers. Severe dilation of the left atrium and pulmonary veins seen on postmortem examination, as well as regurgitant blood flow in the left atrium, demonstrated by Doppler study in ascitic birds, provide evidence that chronically elevated pressure in the left atrium is involved in the aetiology of pulmonary hypertension and ascites in fast-growing broilers.

Arginine therapy: a new treatment for pulmonary hypertension in sickle cell disease?

Pulmonary hypertension is a life-threatening complication of sickle cell disease. L-Arginine is the nitrogen donor for synthesis of nitric oxide, a potent vasodilator that is deficient during times of sickle cell crisis. This deficiency may play a role in pulmonary hypertension. The enzyme arginase hydrolyzes arginine to ornithine and urea, and thus, it may compete with nitric oxide synthase, leading to decreased nitric oxide production. Nitric oxide therapy by inhalation has improved pulmonary hypertension associated with acute chest syndrome in sickle cell disease, and several studies demonstrate therapeutic benefits of arginine therapy for primary and secondary pulmonary hypertension. We sought to determine the effects of arginine therapy on pulmonary hypertension in patients with sickle cell disease. Arginase activity was also determined. Oral arginine produced a 15.2% mean reduction in estimated pulmonary artery systolic pressure (63.9 +/- 13 to 54.2 +/- 12 mm Hg, p = 0.002) after 5 days of therapy in 10 patients. Arginase activity was elevated almost twofold (p = 0.07) in patients with pulmonary hypertension and may limit arginine bioavailability. With limited treatment options and a high mortality rate for patients with sickle cell disease who develop pulmonary hypertension, arginine is a promising new therapy that warrants further investigation.