Prognostic value of the pre-transplant diastolic pulmonary artery pressure-to-pulmonary capillary wedge pressure gradient in cardiac transplant recipients with pulmonary hypertension

Clinical phenotypes and outcomes of pulmonary hypertension due to left heart disease: Role of the pre-capillary component

Background

In pulmonary hypertension (PH), both wedge pressure elevation (PAWP) and a precapillary component may affect right ventricular (RV) afterload. These changes may contribute to RV failure and prognosis. We aimed at describing the different haemodynamic phenotypes of patients with PH due to left heart disease (LHD) and at characterizing the impact of pulmonary haemodynamics on RV function and outcome PH-LHD.

Methods

Patients with PH-LHD were compared with treatment-naïve idiopathic/heritable pulmonary arterial hypertension (PAH, n = 35). PH-LHD patients were subdivided in Isolated post-capillary PH (IpcPH: diastolic pressure gradient, DPG<7 mmHg and pulmonary vascular resistance, PVR≤3 WU, n = 37), Combined post- and pre-capillary PH (CpcPH: DPG≥7 mmHg and PVR>3 WU, n = 27), and “intermediate” PH-LHD (either DPG <7 mmHg or PVR ≤3 WU, n = 29).

Results

Despite similar PAWP and cardiac index, haemodynamic severity and prevalence of RV dysfunction increased from IpcPH, to “intermediate” and CpcPH. PVR and DPG (but not compliance, Ca) were linearly correlated with RV dysfunction. CpcPH had worse prognosis (p<0.05) than IpcPH and PAH, but similar to “intermediate” patients. Only NTproBNP and Ca independently predicted survival in PH-LHD.

Conclusions

In PH-LHD, haemodynamic characterization according to DPG and PVR provides important information on disease severity, predisposition to RV failure and prognosis. Patients presenting the CpcPH phenotype appear to have haemodynamic profile closer to PAH but with worse prognosis. In PH-LHD, Ca and NTproBNP were independent predictors of survival.

Pathophysiology and Diagnosis of Pulmonary Hypertension Due to Left Heart Disease

Pulmonary hypertension due to left heart disease (PH-LHD) is the most common type of pulmonary hypertension, although an accurate prevalence is challenging. PH-LHD includes PH due to systolic or diastolic left ventricular dysfunction, mitral or aortic valve disease and congenital left heart disease. In recent years a new and distinct phenotype of “combined post-capillary and pre-capillary PH,” based on diastolic pulmonary gradient and pulmonary vascular resistance, has been recognized. The roles of right ventricular dysfunction and pulmonary vascular compliance in PH-LHD have also been elucidated recently and they appear to have significant clinical implications. Echocardiography continues to play a seminal role in diagnosis of PH-LHD and heart failure with preserved LV ejection fraction, as it can identify valve disease and help to distinguish PH-LHD from pre-capillary PH. Right, and occasionally left heart catheterization, remains the gold-standard for diagnosis and phenotyping of PH-LHD, although Cardiac Magnetic Resonance Imaging is emerging as a useful alternative tool in non-invasive diagnostic and prognostic assessment of PH-LHD. In this review, the latest evidence for more recent advances will be discussed, including the role of fluid challenge and exercise during cardiac catheterization to unravel occult post-capillary and the role of vasoreactivity testing. The use of many or all of these diagnostic techniques will undoubtedly provide key information about sub-groups of patients with PH-LHD that might benefit from medical therapy previously considered to be only suitable for pulmonary arterial hypertension.

Pulmonary Effective Arterial Elastance as a Measure of Right Ventricular Afterload and Its Prognostic Value in Pulmonary Hypertension Due to Left Heart Disease

BACKGROUND

Patients with combined post- and precapillary pulmonary hypertension due to left heart disease have a worse prognosis compared with isolated postcapillary. However, it remains unclear whether increased mortality in combined post- and precapillary pulmonary hypertension is simply a result of higher total right ventricular load. Pulmonary effective arterial elastance (Ea) is a measure of total right ventricular afterload, reflecting both resistive and pulsatile components. We aimed to test whether pulmonary Ea discriminates survivors from nonsurvivors in patients with pulmonary hypertension due to left heart disease and if it does so better than other hemodynamic parameters associated with combined post- and precapillary pulmonary hypertension.

METHODS AND RESULTS

We combined 3 large heart failure patient cohorts (n=1036) from academic hospitals, including patients with pulmonary hypertension due to heart failure with preserved ejection fraction (n=232), reduced ejection fraction (n=335), and a mixed population (n=469). In unadjusted and 2 adjusted models, pulmonary Ea more robustly predicted mortality than pulmonary vascular resistance and the transpulmonary gradient. Along with pulmonary arterial compliance, pulmonary Ea remained predictive of survival in patients with normal pulmonary vascular resistance. The diastolic pulmonary gradient did not predict mortality. In addition, in a subset of patients with echocardiographic data, Ea and pulmonary arterial compliance were better discriminators of right ventricular dysfunction than the other parameters.

CONCLUSIONS

Pulmonary Ea and pulmonary arterial compliance more consistently predicted mortality than pulmonary vascular resistance or transpulmonary gradient across a spectrum of left heart disease with pulmonary hypertension, including patients with heart failure with preserved ejection fraction, heart failure with reduced ejection fraction, and pulmonary hypertension with a normal pulmonary vascular resistance.

In-depth haemodynamic phenotyping of pulmonary hypertension due to left heart disease

The commonest cause of pulmonary hypertension (PH) is left heart disease (LHD). The current classification system for definitions of PH-LHD is under review. We therefore performed prospective in-depth invasive haemodynamic phenotyping in order to assess the site of increased pulmonary vascular resistance (PVR) in PH-LHD subsets.

Based on pulmonary artery occlusion waveforms yielding an estimate of the effective capillary pressure, we partitioned PVR in larger arterial (Rup, upstream resistance) and small arterial plus venous components (Rds, downstream resistance). In the case of small vessel disease, Rup decreases and Rds increases. Inhaled nitric oxide (NO) testing was used to assess acute vasoreactivity.

Right ventricular afterload (PVR, pulmonary arterial compliance and effective arterial elastance) was significantly higher in combined post- and pre-capillary PH (Cpc-PH, n=35) than in isolated post-capillary PH (Ipc-PH, n=20). Right ventricular afterload decreased during inhalation of NO in Cpc-PH and idiopathic pulmonary arterial hypertension (n=31), but remained unchanged in Ipc-PH. Rup was similar in Cpc-PH (66.8±10.8%) and idiopathic pulmonary arterial hypertension (65.0±12.2%; p=0.530) suggesting small vessel disease, but significantly higher in Ipc-PH (96.5±4.5%; p<0.001) suggesting upstream transmission of elevated left atrial pressure.

Right ventricular afterload is driven by elevated left atrial pressure in Ipc-PH and is further increased by elevated small vessel resistance in Cpc-PH. Cpc-PH is responsive to inhaled NO. Our data support current definitions of PH-LHD subsets.

Diastolic pressure indices offer a novel approach to predicting risk of graft loss after pediatric heart transplant

PH is a risk factor for GL after HTx. However, traditional parameters are not reliable predictors of risk in children. We hypothesized that DPI (dPAP and DPG) are predictive of GL in pediatric HTx recipients. The UNOS/SRTR database was reviewed to identify pediatric HTx recipients (age <18 years) between 1994 and 2013. Recipients with pretransplant hemodynamic data were grouped by diagnosis (CMP or CHD), and the groups were analyzed separately. Bivariate Cox regression analysis examined the association between hemodynamic variables and GL. DPI showed the strongest association with early GL in recipients with CMP (dPAP: HR = 1.25 [1.09-1.42]; DPG: 1.24 [1.11-1.38]). Among CHD recipients, DPI were associated with early GL in those with preexisting PH (dPAP: HR = 1.16 [1.01-1.33]; DPG: HR = 1.10 [1.00-1.21]). No cutoff values for "high-risk" DPI were identified, but a continuous relationship between higher DPI and risk of early GL was observed. DPI are associated with early GL in select pediatric HTx recipients. Our findings suggest that DPI should be considered as part of routine hemodynamic assessment for pediatric HTx candidates.

Dominance of free wall radial motion in global right ventricular function of heart transplant recipients

Assessment of right ventricular (RV) function using conventional echocardiography might be inadequate as the radial motion of the RV free wall is often neglected. Our aim was to quantify the longitudinal and the radial components of RV function using three-dimensional (3D) echocardiography in heart transplant (HTX) recipients. Fifty-one HTX patients in stable cardiovascular condition without history of relevant rejection episode or chronic allograft vasculopathy and 30 healthy volunteers were enrolled. RV end-diastolic (EDV) volume and total ejection fraction (TEF) were measured by 3D echocardiography. Furthermore, we quantified longitudinal (LEF) and radial ejection fraction (REF) by decomposing the motion of the RV using the ReVISION method. RV EDV did not differ between groups (HTX vs control; 96 ± 27 vs 97 ± 2 mL). In HTX patients, TEF was lower, however, tricuspid annular plane systolic excursion (TAPSE) decreased to a greater extent (TEF: 47 ± 7 vs 54 ± 4% [-13%], TAPSE: 11 ± 5 vs 21 ± 4 mm [-48%], P < .0001). In HTX patients, REF/TEF ratio was significantly higher compared to LEF/TEF (REF/TEF vs LEF/TEF: 0.58 ± 0.10 vs 0.27 ± 0.08, P < .0001), while in controls the REF/TEF and LEF/TEF ratio was similar (0.45 ± 0.07 vs 0.47 ± 0.07). Current results confirm the superiority of radial motion in determining RV function in HTX patients. Parameters incorporating the radial motion are recommended to assess RV function in HTX recipients.

Pulmonary Hypertension in Heart Failure Patients: Pathophysiology and Prognostic Implications

Pulmonary hypertension (PH) due to left heart disease (LHD), i.e., group 2 PH, is the most common reason for increased pressures in the pulmonary circuit. Although recent guidelines incorporate congenital heart disease in this classification, left-sided heart diseases of diastolic and systolic origin including valvular etiology are the vast majority. In these patients, an increased left-sided filling pressure triggers a multistage hemodynamic evolution that ends into right ventricular failure through an initial passive increase in pulmonary artery pressure complicated over time by pulmonary vasoconstriction, endothelial dysfunction, and remodeling of the small-resistance pulmonary arteries. Regardless of the underlying left heart pathology, when present, PH-LHD is associated with more severe symptoms, worse exercise tolerance, and outcome, especially when right ventricular dysfunction and failure are part of the picture. Compared with group 1 and other forms of pulmonary arterial hypertension, PH-LHD is more often seen in elderly patients with a higher prevalence of cardiovascular comorbidities and most, if not all, of the features of metabolic syndrome, especially in case of HF preserved ejection fraction. In this review, we provide an update on current knowledge and some potential challenges about the pathophysiology and established prognostic implications of group 2 PH in patients with HF of either preserved or reduced ejection fraction.

Pulmonary Hypertension Due to Left Ventricular Cardiomyopathy: Is it the Result or Cause of Disease Progression?

PURPOSE OF REVIEW

The purpose of this review is to define pulmonary hypertension in the setting of left heart disease (PH-LHD), discuss its epidemiology and pathophysiology, and highlight the cause and effect relationship it has with disease progression in the setting of cardiomyopathy.

RECENT FINDINGS

Both pulmonary hypertension (PH) and heart failure are becoming increasingly common. As such, PH-LHD is now the most common form of PH. The pathophysiology of the condition relates to backward transmission of elevated left ventricular filling pressures into the pulmonary circulation and, ultimately, right ventricular (RV) strain/dysfunction. It is evident that these pathophysiologic processes are both the effect and cause of left heart disease progression. In this review, we describe the complex relationship between disease progression in left ventricular cardiomyopathy and PH-LHD. Clinicians and researchers should take note of the importance of PH-LHD and RV dysfunction to appropriately risk stratify patients and develop therapies for the condition.

Persistent abnormalities in pulmonary arterial compliance after heart transplantation in patients with combined post-capillary and pre-capillary pulmonary hypertension

Background

The hemodynamic definitions of pulmonary hypertension (PH) in left heart disease have recently been refined to better match the characteristics required to reflect the presence of pulmonary vascular disease. Accordingly, we tested the hypothesis that abnormalities in the stiffness of pulmonary circulation would persist after heart transplantation in patients with combined post-capillary and pre-capillary PH (Cpc-PH) in contrast to those with isolated post-capillary PH (Ipc-PH).

Methods

We retrospectively analyzed right heart hemodynamics in a cohort of 295 consecutive patients with heart failure and advanced left ventricular systolic dysfunction (LVSD) before and 1 year after heart transplantation.

Results

According to their baseline hemodynamic profile, patients were classified as: 75 Cpc-PH, 111 Ipc-PH, and 98 without PH (no-PH), and 11 pre-capillary PH. One year after heart transplantation, pulmonary artery pressures, pulmonary vascular resistance and cardiac index normalized in all patients regardless of the baseline hemodynamic profile. However, pulmonary arterial compliance remained lower in Cpc-PH patients (from 1.6±1.2 at baseline to 3.7±1.4 ml/mmHg at 1 year) than in Ipc-PH (from 1.2±2.0 to 4.4±2.3 ml/mmHg) and no-PH patients (from 3.7±2.0 to 4.5±1.8 ml/mmHg); (adjusted p = 0.03 Ipc-PH vs. Cpc-PH _INT<0.001).

Conclusions

In heart failure patients with advanced LVSD, a hemodynamic profile characterized by Cpc-PH predicts the persistence of a stiffer pulmonary circulation at 1 year after heart transplantation.

Haemodynamic effects of an acute vasodilator challenge in heart failure patients with reduced ejection fraction and different forms of post-capillary pulmonary hypertension

AIMS

The most recent European guidelines have proposed new definitions of pulmonary hypertension (PH) in left heart disease, to better approach the characteristics required to reflect the presence of pulmonary vascular disease. The purpose of this study was to assess whether different haemodynamic definitions of post-capillary PH imply a different reversibility of PH in response to acute vasodilator administration in heart failure patients with reduced ejection fraction and PH (HFrEF-PH).

METHODS AND RESULTS

Right heart catheterization and reversibility testing was performed in 156 HFrEF-PH patients. Patients were classified as combined post-capillary and pre-capillary pulmonary hypertension (Cpc-PH) vs. isolated post-capillary pulmonary hypertension (Ipc-PH) and on the basis of diastolic pulmonary gradient (DPG) ≥ 7 vs. < 7 mmHg or of transpulmonary gradient (TPG) >12 vs. ≤12 mmHg. After vasodilator administration, Cpc-PH patients showed a greater per cent improvement in pulmonary vascular resistance (PVR), DPG and TPG as compared with Ipc-PH patients (all P_int < 0.001); only pulmonary compliance (PCa) improved less in Cpc-PH than in Ipc-PH patients (P_int = 0.007). However, despite vasodilatation, Cpc-PH patients remained in an unfavourable portion of the inverse hyperbolic relationship between PVR and PCa. The number of patients in whom PVR was reduced below 2.5 wood units was similar in Cpc-PH, DPG ≥7 mmHg and TPG >12 mmHg groups (28.3, 26.7 and 18.9%, respectively).

CONCLUSION

Although substantial improvements in PVR, DPG and TPG were observed in Cpc-PH patients after acute vasodilator administration, this response was associated with persistent abnormalities in the PVR vs. PCa relationship. The link between baseline right heart haemodynamics and pulmonary vascular disease remains elusive.

A critical appraisal of transpulmonary and diastolic pressure gradients

Pulmonary hypertension (PH) resulting from left heart failure is an increasingly recognized clinical entity. To distinguish isolated postcapillary PH from combined post‐ and precapillary PH, the use of a diastolic pressure gradient (DPG = diastolic Pulmonary Artery Pressure − Pulmonary Arterial Wedge Pressure, dPAP − PAWP) has been advocated over the transpulmonary pressure gradient (TPG = mean Pulmonary Artery Pressure − PAWP, mPAP − PAWP) since DPG was suggested to be independent of cardiac output (CO) and only slightly related to PAWP, while TPG depends on both. We quantitatively derived and compared the DPG and TPG. Using right heart catheterization data (n = 1054), we determined systolic pulmonary artery pressure (sPAP), dPAP and mPAP, PAWP, and CO. From this data, we derived TPG and DPG and tested their dependence on PAWP and CO. We found that dPAP and sPAP are proportional with mPAP over a wide range of PAWP (1–31 mmHg), with dPAP = 0.62mPAP and sPAP = 1.61mPAP. As a consequence, TPG and DPG are equally dependent on PAWP: TPG = mPAP − PAWP, and DPG = 0.62mPAP − PAWP. Furthermore, we showed that both TPG and DPG depend on CO. The absolute increase in DPG with CO is 62% of the TPG increase with CO, but the relative dependence is the same. Both TPG and DPG depend on PAWP and CO. Thus, in principle, there are no major advantages for using DPG to distinguish postcapillary pulmonary hypertension from combined post‐ and precapillary pulmonary hypertension.

Pulmonary hemodynamics in heart failure patients with reduced or preserved ejection fraction and pulmonary hypertension: Similarities and disparities

OBJECTIVE

The current understanding of pulmonary hypertension (PH) due to left ventricular diseases does not distinguish heart failure (HF) with reduced ejection fraction (HFrEF) from HF and preserved ejection fraction (HFpEF), in terms of pulmonary hemodynamics. The value of pulmonary vascular compliance (PCa) and diastolic pulmonary gradient (DPG) as predictors of survival in either HF syndrome is controversial. The aims of our study were to compare the pulmonary hemodynamics in the two HF phenotypes, given similar values of pulmonary artery wedge pressure (PAWP), and to evaluate the impact of PCa and DPG on survival.

METHODS

We retrospectively reviewed the charts of 168 PH-HFrEF and 86 PH-HFpEF patients. The independent association of PCa and DPG with prognosis was assessed by means of a Cox proportional hazard model. All cause survival was analyzed over an average follow-up period of 50 months.

RESULTS

PH-HFpEF patients had a significantly higher DPG than PH-HFrEF patients (6.1±7.1 vs 1.8±4.5 mmHg, adjusted P=.025). PCa was similar in PH-HFpEF and PH-HFrEF. PCa was a significant predictor of survival, according to previously described preset cutoffs (2.15 mL/mmHg in HFrEF and 1.1 mL/mmHg in HFpEF) and based on a continuous scale; whereas DPG had no impact on survival in both patients groups.

CONCLUSION

Our findings suggest that for similar levels of PAWP, pulmonary circulation may be stiffer in patients with HFpEF-PH than patients with HFrEF-PH, leading to higher DPGs. Nonetheless, PCa rather than DPG emerged as the stronger predictor of survival in both left-sided PH phenotypes.

Preoperative Invasive Hemodynamic Determinants of Survival Among Patients Undergoing Aortic or Mitral Valve Surgery

OBJECTIVES

To evaluate the association of preoperative invasive hemodynamic parameters with mortality in valvular heart surgery.

DESIGN

Retrospective cohort study.

SETTING

Single tertiary academic medical center.

PARTICIPANTS

A total of 382 patients who underwent preoperative right and/or left heart catheterization before open aortic valve replacement (AVR), open mitral valve repair/replacement (MVR), or combined AVR and MVR, from July 2009 to December 2014.

INTERVENTIONS

Retrospective chart review.

MEASUREMENTS AND MAIN RESULTS

Common hemodynamic indices derived from direct catheterization measurements were assessed, including pulmonary artery systolic pressure (PASP), pulmonary artery pulse pressure (PPP), mean pulmonary capillary wedge pressure (mPCWP), pulmonary artery pulsatility index, diastolic pressure gradient, left ventricular work index, and right ventricular work index. Bivariable and multivariable associations of these measures with survival were determined using Cox proportional hazards regression. Kaplan-Meier survival curves were generated using the log-rank test. The median age of the cohort was 69 years (interquartile range 60-79 years), and 162 (42.4%) of the patients were female. Elevated PASP (hazard ratio [HR] 1.32 per 10 mmHg, p < 0.0001), elevated PPP (HR 1.48 per 10 mmHg, p < 0.0001), and elevated mPCWP (HR 1.95 per 10 mmHg, p < 0.0001) were all associated with decreased survival, as was decreased diastolic blood pressure (DBP) (p = 0.005). The combination of elevated PPP and decreased DBP was associated with the worst outcomes.

CONCLUSIONS

PASP, PPP, mPCWP, and DBP were significantly associated with mortality in valvular heart surgery patients. These hemodynamic parameters may be useful in risk stratification of this population subset.

Hemodynamic Phenotyping of Pulmonary Hypertension in Left Heart Failure

Increased pulmonary venous pressure secondary to left heart disease is the most common cause of pulmonary hypertension (PH). The diagnosis of PH due to left heart disease relies on a clinical probability assessment followed by the invasive measurements of a mean pulmonary artery pressure (PAP) ≥25 mm Hg and mean wedged PAP (PAWP) >15 mm Hg. A combination of mean PAP and mean PAWP defines postcapillary PH. Postcapillary PH is generally associated with a diastolic pulmonary pressure gradient (diastolic PAP minus mean PAWP) <7 mm Hg, a transpulmonary pressure gradient (mean PAP minus mean PAWP) <12 mm Hg, and pulmonary vascular resistance ≤3 Wood units (WU). This combination of criteria defines isolated postcapillary PH. Postcapillary PH with elevated vascular gradients and pulmonary vascular resistance defines combined post- and precapillary PH (Cpc-PH). Postcapillary PH is associated with a decreased survival in proportion to increased pulmonary vascular gradients, decreased pulmonary arterial compliance, and reduced right ventricular function. The Cpc-PH subcategory occurs in 12% to 13% of patients with PH due to left heart disease. Patients with Cpc-PH have severe PH, with higher diastolic pulmonary pressure gradient, transpulmonary pressure gradient, and pulmonary vascular resistance and more pronounced ventilatory responses to exercise, lower pulmonary arterial compliance, depressed right ventricular ejection fraction, and shorter life expectancy than isolated postcapillary PH. Cpc-PH bears similarities to pulmonary arterial hypertension. Whether Cpc-PH is amenable to therapies targeting the pulmonary circulation remains to be tested by properly designed randomized controlled trials.

Diastolic Pressure Difference to Classify Pulmonary Hypertension in the Assessment of Heart Transplant Candidates

BACKGROUND

The diastolic pressure difference (DPD) is recommended to differentiate between isolated postcapillary and combined pre-/postcapillary pulmonary hypertension (Cpc-PH) in left heart disease (PH-LHD). However, in usual practice, negative DPD values are commonly calculated, potentially related to the use of mean pulmonary artery wedge pressure (PAWP). We used the ECG to gate late-diastolic PAWP measurements. We examined the method's impact on calculated DPD, PH-LHD subclassification, hemodynamic profiles, and mortality.

METHODS AND RESULTS

We studied patients with advanced heart failure undergoing right heart catheterization to assess cardiac transplantation candidacy (N=141). Pressure tracings were analyzed offline over 8 to 10 beat intervals. Diastolic pulmonary artery pressure and mean PAWP were measured to calculate the DPD as per usual practice (diastolic pulmonary artery pressure-mean PAWP). Within the same intervals, PAWP was measured gated to the ECG QRS complex to calculate the QRS-gated DPD (diastolic pulmonary artery pressure-QRS-gated PAWP). Outcomes occurring within 1 year were collected retrospectively from chart review. Overall, 72 of 141 cases demonstrated PH-LHD. Within PH-LHD, the QRS-gated DPD yielded higher calculated DPD values (3 [-1 to 6] versus 0 [-4 to 3] mm Hg; P<0.01) and a greater proportion of Cpc-PH (24% versus 8%; P<0.01) versus the usual practice DPD. Cases reclassified as Cpc-PH based on QRS-gated DPD demonstrated higher pulmonary arterial pressures versus isolated postcapillary pulmonary hypertension (P<0.05). One-year mortality was similar between PH-LHD groups.

CONCLUSIONS

The DPD calculated in usual practice is underestimated in PH-LHD, which may classify Cpc-PH patients as isolated postcapillary pulmonary hypertension. The QRS-gated DPD reclassifies a subset of PH-LHD patients from isolated postcapillary pulmonary hypertension to Cpc-PH, which is characterized by an adverse hemodynamic profile.

Decoupling Between Diastolic Pulmonary Artery Pressure and Pulmonary Capillary Wedge Pressure as a Prognostic Factor After Continuous Flow Ventricular Assist Device Implantation

BACKGROUND

A cohort of heart failure (HF) patients receiving left ventricular assist devices (LVADs) has decoupling of their diastolic pulmonary artery pressure and pulmonary capillary wedge pressure. However, the clinical implications of this decoupling remain unclear.

METHODS AND RESULTS

In this prospective study, patients with LVADs underwent routine invasive hemodynamic ramp testing with right heart catheterization, during which LVAD speeds were adjusted. Inappropriate decoupling was defined as a >5 mm Hg difference between diastolic pulmonary artery pressure and pulmonary capillary wedge pressure. The primary outcomes of survival and heart failure readmission rates after ramp testing were assessed. Among 63 LVAD patients (60±12 years old and 25 female [40%]), 27 patients (43%) had inappropriate decoupling at their baseline speed. After adjustment of their rotation speed during ramp testing, 30 patients (48%) had inappropriate decoupling. Uni/multivariable Cox analyses demonstrated that decoupling was the only significant predictor for the composite end point of death and heart failure readmission during the 1 year following the ramp study (total of 18 events; hazards ratio, 1.09; 95% confidence interval, 1.04-1.24; P<0.05). Furthermore, normalization of decoupling (n=8) during ramp testing was significantly associated with higher 1-year heart failure readmission-free survival rate compared with the non-normalized group (n=19, 100% versus 53%; P=0.035).

CONCLUSIONS

The presence of inappropriate decoupling was associated with worse outcomes in patients with LVADs. Prospective, large-scale multicenter studies to validate the result are warranted.

Clinical and Biological Insights Into Combined Post- and Pre-Capillary Pulmonary Hypertension

BACKGROUND

Pulmonary hypertension (PH) is a common and morbid complication of left heart disease with 2 subtypes: isolated post-capillary pulmonary hypertension (Ipc-PH) and combined post-capillary and pre-capillary pulmonary hypertension (Cpc-PH). Little is known about the clinical or physiological characteristics that distinguish these 2 subphenotypes or if Cpc-PH shares molecular similarities to pulmonary arterial hypertension (PAH).

OBJECTIVES

The goal of this study was to test the hypothesis that the hemodynamic and genetic profile of Cpc-PH would more closely resemble PAH than Ipc-PH.

METHODS

Vanderbilt University's electronic medical record linked to a DNA biorepository was used to extract demographic characteristics, clinical data, invasive hemodynamic data, echocardiography, and vital status for all patients referred for right heart catheterization between 1998 and 2014. Shared genetic variants between PAH and Cpc-PH compared with Ipc-PH were identified by using pre-existing single-nucleotide polymorphism data.

RESULTS

A total of 2,817 patients with PH (13% Cpc-PH, 52% Ipc-PH, and 20% PAH) were identified. Patients with Cpc-PH were on average 6 years younger, with more severe pulmonary vascular disease than patients with Ipc-PH, despite similar comorbidities and prevalence, severity, and chronicity of left heart disease. After adjusting for relevant covariates, the risk of death was similar between the Cpc-PH and Ipc-PH groups (hazard ratio: 1.14; 95% confidence interval: 0.96 to 1.35; p = 0.15) when defined according to diastolic pressure gradient. We identified 75 shared exonic single-nucleotide polymorphisms between Cpc-PH and PAH enriched in pathways involving cell structure, extracellular matrix, and immune function. These genes are expressed, on average, 32% higher in lungs relative to other tissues.

CONCLUSIONS

Patients with Cpc-PH develop pulmonary vascular disease similar to patients with PAH, despite younger age and similar prevalence of obesity, diabetes mellitus, and left heart disease compared with patients with Ipc-PH. An exploratory genetic analysis in Cpc-PH identified genes and biological pathways in the lung known to contribute to PAH pathophysiology, suggesting that Cpc-PH may be a distinct and highly morbid PH subphenotype.

Ventricular Diastolic Pressure Ratio as a Marker of Treatment Response in Pulmonary Hypertension

BACKGROUND

Pulmonary hypertension (PH) is diagnosed and classified through right-sided heart catheterization, with a number of hemodynamic markers used to help guide treatment decisions. These markers may not reflect the complex remodeling of the right ventricle or the interplay between ventricles and struggle to predict treatment response. This study investigates the use of a novel marker: the ratio of left ventricular end-diastolic pressure to right ventricular end-diastolic pressure (LVEDP/RVEDP) in predicting treatment outcomes in a cohort of patients with PH.

METHODS

We performed a retrospective analysis of patients with PH at INOVA Fairfax Hospital's advanced lung disease program with simultaneous left-sided and right-sided heart catheterization. The primary end point was the time to clinical improvement, defined by an improvement in distance walked on the 6-min walk test (6MWT) of > 35 m in a year without interceding hospitalization for worsening PH or the need for additional PH therapy.

RESULTS

A total of 51 patients were included in the final analysis, 21 of whom (41.2%) had a salutary treatment effect with a mean improvement in the 6MWT of 75 m. Treatment responders were more likely to have a lower LVEDP/RVEDP ratio (1.08 vs 1.62; P = .051). This association persisted in the final multivariate regression model after adjustment for age and sex and controlling for severity of PH (OR, 0.17; 95% CI, 0.03-0.65; P = .024).

CONCLUSIONS

The LVEDP/RVEDP ratio is a novel marker for therapeutic response in patients with PH treated with pulmonary vasodilator medications and may offer robust predictive value independent of existing markers of disease severity.

The prognostic importance of the diastolic pulmonary gradient, transpulmonary gradient, and pulmonary vascular resistance in patients undergoing transcatheter aortic valve replacement

OBJECTIVES

To evaluate the association between markers of precapillary pulmonary hypertension (PH) and survival in transcatheter aortic valve replacement (TAVR).

BACKGROUND

The importance of precapillary PH has been sparsely investigated in patients undergoing TAVR. It may prove an important risk factor for poor outcomes.

METHODS

We identified patients at our institution undergoing TAVR with a baseline right heart catheterization (RHC) demonstrating PH. We evaluated the association between markers of precapillary PH and survival including the diastolic pulmonary gradient (DPG), transpulmonary gradient (TPG), and pulmonary vascular resistance (PVR). A multivariable analysis was performed using Cox Proportional Hazards Models, adjusting for age, gender, body mass index, and pulmonary artery systolic pressure (PASP) on echocardiography.

RESULTS

We identified 133 patients with PH on RHC. Of these 111 had low DPG and 22 had high DPG. All 3 markers of precapillary PH were associated with worse survival post TAVR, with OR of 2.1 (95% CI 1.1-3.9, P = 0.02), 3.4 (95% CI 1.8-6.4, P < 0.001) and 2.5 (95% CI 1.4-4.5, P = 0.003) for high DPG, TPG, and PVR, respectively. On multivariable analysis, both TPG and PVR remained predictors of worse survival, with OR of 3.4 (95% CI 1.7-6.9, P = 0.001) and 2.5 (95% CI 1.4-4.5, P = 0.003). Echocardiographic PASP and DPG were not predictive of survival.

CONCLUSIONS

In patients undergoing TAVR, parameters of precapillary PH are associated with lower survival, and provide incremental prognostication over echocardiographic PASP. RHC should continue to play an important role in risk stratification prior to TAVR. © 2017 Wiley Periodicals, Inc.

Pulmonary hypertension due to left heart disease

Pulmonary hypertension due to left heart disease, also known as group 2 pulmonary hypertension according to the European Society of Cardiology/European Respiratory Society classification, is the most common cause of pulmonary hypertension. In patients with left heart disease, the development of pulmonary hypertension favours right heart dysfunction, which has a major impact on disease severity and outcome. Over the past few years, this condition has been considered more frequently. However, epidemiological studies of group 2 pulmonary hypertension are less exhaustive than studies of other causes of pulmonary hypertension. In group 2 patients, pulmonary hypertension may be caused by an isolated increase in left-sided filling pressures or by a combination of this condition with increased pulmonary vascular resistance, with an abnormally high pressure gradient between arteries and pulmonary veins. A better understanding of the conditions underlying pulmonary hypertension is of key importance to establish a comprehensive diagnosis, leading to an adapted treatment to reduce heart failure morbidity and mortality. In this review, epidemiology, mechanisms and diagnostic approaches are reviewed; then, treatment options and future approaches are considered.

Poor survival in patients with scleroderma and pulmonary hypertension due to heart failure with preserved ejection fraction

Pulmonary hypertension due to heart failure with preserved ejection fraction (PH-HFpEF) has been poorly studied in patients with systemic sclerosis (SSc). We sought to compare clinical characteristics and survival of SSc patients with PH-HFpEF (SSc-PH-HFpEF) versus pulmonary arterial hypertension (SSc-PAH). We hypothesized that patients with SSc-PH-HFpEF have a similar poor overall prognosis compared with patients with SSc-PAH when matched for total right ventricular load. The analysis included 117 patients with SSc-PH (93 with SSc-PAH versus 24 with SSc-PH-HFpEF) enrolled prospectively in the Johns Hopkins PH Registry. We examined baseline demographics and hemodynamics at diagnostic right heart catheterization (RHC), two-dimensional echocardiographic characteristics, six-minute walking distance (6MWD), treatment modalities, and laboratory values (serum NT-proBNP, creatinine, uric acid, and sodium), and assessed survival. Demographics and clinical features were similar between the two groups. Baseline RHC showed significantly higher pulmonary and right heart pressures in the SSc-PH-HFpEF compared with the SSc-PAH group. Trans-pulmonary gradient (TPG), however, was equally elevated without significant difference between the groups. SSc-PH-HFpEF patients had left atrial enlargement on echocardiography compared with SSc-PAH patients. No significant differences were found between groups for 6MWD, NT-proBNP, and other laboratory values. Although overall median survival time was 4.6 years with no difference in mortality rate between the two groups (SSc-PH-HFpEF versus SSc-PAH: 75% versus 59%; P = 0.26), patients with SSc-PH-HFpEF had a twofold increased risk of death compared with SSc-PAH patients after adjusting for hemodynamics. Concomitant intrinsic pulmonary vascular disease and HFpEF likely contribute to very poor survival in patients with SSc-PH-HFpEF.

Impact of postoperative pulmonary hypertension on outcome after heart transplantation

OBJECTIVES

We wanted to investigate the effects of postoperative pulmonary hypertension (PH_postop: mean pulmonary artery pressure [MPAP] ≥ 25 mmHg), diastolic pressure gradient (DPG), pulmonary vascular resistance (PVR), and repeated hemodynamic measurements on long-term survival after heart transplantation (HT).

DESIGN

Eighty-nine patients who underwent HT at Skåne University Hospital in Lund in the period 1988-2010 and who were evaluated with right-heart-catheterization at rest, prior to HT and repeatedly during the first postoperative year, were grouped based on their MPAP, DPG, and PVR.

RESULTS

One year after HT, survival was lower in patients with PH_postop than in those without, in patients with DPG ≥7 mmHg than in those with DPG <7 mmHg, and in patients with PVR >3 WU than in those with PVR ≤3 WU. Moreover, compared to patients with no PH_postop or with PH_postop at one evaluation during the first year after HT, PH_postop at repeated evaluations was associated with higher mortality (hazard ratio 3.4, 95% CI 1.4-8.0). There was no significant difference in acute cellular rejection between patients with and without PH_postop, but postoperative kidney function was worse in patients with repeated PH_postop.

CONCLUSIONS

When defined according to present guidelines, PH one year after HT may emerge as a prognostic marker for long-term outcome after HT. Moreover, PH_postop at repeated evaluations during the first year after HT had stronger prognostic value than PH_postop at a single examination, illustrating a means of identifying a high-risk population. However, confirmation in larger multi-center studies is warranted.

Pulmonary hypertension associated with left-sided heart disease

Pulmonary hypertension associated with left-sided heart disease (PH-LHD) is the most common type of pulmonary hypertension. In patients with left-sided heart disease, the presence of pulmonary hypertension is typically a marker of more advanced disease, more severe symptoms, and worse prognosis. In contrast to pulmonary arterial hypertension, PH-LHD is characterised by an elevated pulmonary artery wedge pressure (postcapillary pulmonary hypertension) without or with an additional precapillary component (isolated postcapillary vs combined postcapillary and precapillary pulmonary hypertension). Transthoracic echocardiography is the primary noninvasive imaging tool to estimate the probability of pulmonary hypertension and to establish a working diagnosis on the mechanism of pulmonary hypertension. However, right heart catheterisation is always required if significant pulmonary hypertension is suspected and exact knowledge of the haemodynamic constellation is necessary. The haemodynamic constellation (mean pulmonary artery pressure, mean pulmonary artery wedge pressure, left ventricular end-diastolic pressure) in combination with clinical information and imaging findings (mainly echocardiography, coronary angiography and cardiac magnetic resonance imaging) will usually allow the exact mechanism underlying PH-LHD to be defined, which is a prerequisite for appropriate treatment. The general principle for the management of PH-LHD is to treat the underlying left-sided heart disease in an optimal manner using drugs and/or interventional or surgical therapy. There is currently no established indication for pulmonary arterial hypertension-specific therapies in PH-LHD, and specific therapies may even cause harm in patients with PH-LHD.

Pulmonary hypertension and ventilation during exercise: Role of the pre-capillary component

BACKGROUND

Excessive exercise-induced hyperventilation and high prevalence of exercise oscillatory breathing (EOB) are present in patients with post-capillary pulmonary hypertension (PH) complicating left heart disease (LHD). Patients with pre-capillary PH have even higher hyperventilation but no EOB. We sought to determine the impact of a pre-capillary component of PH on ventilatory response to exercise in patients with PH and left heart disease.

METHODS

We retrospectively compared patients with idiopathic or heritable pulmonary arterial hypertension (PAH, n = 29), isolated post-capillary PH (IpcPH, n = 29), and combined post- and pre-capillary PH (CpcPH, n = 12). Diastolic pressure gradient (DPG = diastolic pulmonary artery pressure - pulmonary wedge pressure) was used to distinguish IpcPH (DPG <7 mm Hg) from CpcPH (DPG ≥7 mm Hg).

RESULTS

Pulmonary vascular resistance (PVR) was higher in PAH, intermediate in CpcPH, and low in IpcPH. All patients with CpcPH but 1 had PVR >3 Wood unit. Exercise-induced hyperventilation (high minute ventilation over carbon dioxide production, low end-tidal carbon dioxide) was marked in PAH, intermediate in CpcPH, and low in IpcPH (p < 0.001) and correlated with DPG and PVR. Prevalence of EOB decreased from IpcPH to CpcPH to PAH (p < 0.001).

CONCLUSIONS

Patients with CpcPH may have worse hemodynamics than patients with IpcPH and distinct alterations of ventilatory control, consistent with more exercise-induced hyperventilation and less EOB. This might be explained at least in part by the presence and extent of pulmonary vascular disease.

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.

Determinants and prognostic implications of the negative diastolic pulmonary pressure gradient in patients with pulmonary hypertension due to left heart disease

AIMS

The diastolic pulmonary pressure gradient (DPG) has recently been introduced as a specific marker of combined pre-capillary pulmonary hypertension (Cpc-PH) in left heart disease (LHD). However, its diagnostic and prognostic superiority compared with traditional haemodynamic indices has been challenged lately. Current recommendations explicitly denote that in the normal heart, DPG values are greater than zero, with DPG ≥7 mmHg indicating Cpc-PH. However, clinicians are perplexed by the frequent observation of DPG <0 mmHg (DPG_NEG ), as its physiological explanation and clinical impact are unclear to date. We hypothesized that large V-waves in the pulmonary artery wedge pressure (PAWP) curve yielding asymmetric pressure transmission might account for DPG_NEG and undertook this study to clarify the physiological and prognostic implications of DPG_NEG .

METHODS AND RESULTS

Right heart catheterization and echocardiography were performed in 316 patients with LHD due to primary myocardial dysfunction or valvular disease. A total of 256 patients had PH-LHD, of whom 48% demonstrated DPG_NEG . The V-wave amplitude inversely correlated with DPG (r = -0.45, P < 0.001) in patients with low pulmonary vascular resistance (PVR), but not in those with elevated PVR (P > 0.05). Patients with large V-waves had negative and lower DPG than those without augmented V-waves (P < 0.001) despite similar PVR (P >0.05). Positive, but normal DPG (0-6 mmHg) carried a worse 2-year prognosis for death and/or heart transplantation than DPG_NEG (hazard ratio 2.97; P < 0.05).

CONCLUSION

Our results advocate against DPG_NEG constituting a measurement error. We propose that DPG_NEG can partially be ascribed to large V-waves and carries a better prognosis than DPG within the normal positive range.

Physiological Techniques and Pulmonary Hypertension - Left Heart Disease

Group 2 Pulmonary hypertension (PH) is associated with left heart disease (LHD;Group 2 PH) and is the most common form of PH. Group 2 PH represents an important subgroup of patients with LHD where the development of PH leads to a significant increase in morbidity and mortality. Early diagnosis may provide an opportunity to intervene and significantly delay progression. In addition to clinical suspicion, several approaches including hemodynamic assessment, exercise testing, and imaging techniques play an important role in better disease characterization and management. Here, we review the role of physiologic based hemodynamic and exercise assessments of Group 2 PH patients.

Pulmonary hypertension in patients with heart failure and preserved ejection fraction: differential diagnosis and management

The most common cause of pulmonary hypertension (PH) due to left heart disease (LHD) was previously rheumatic mitral valve disease. However, with the disappearance of rheumatic fever and an aging population, nonvalvular LHD is now the most common cause of group 2 PH in the developed world. In this review, we examine the challenge of investigating patients who have PH and heart failure with preserved ejection fraction (HF-pEF), where differentiating between pulmonary arterial hypertension (PAH) and PH-LHD can be difficult, and also discuss the entity of combined precapillary and postcapillary PH. Given the proven efficacy of targeted therapy for the treatment of PAH, there is increasing interest in whether these treatments may benefit selected patients with PH associated with HF-pEF, and we review current trial data.

Left ventricular heart failure and pulmonary hypertension

In patients with left ventricular heart failure (HF), the development of pulmonary hypertension (PH) and right ventricular (RV) dysfunction are frequent and have important impact on disease progression, morbidity, and mortality, and therefore warrant clinical attention. Pulmonary hypertension related to left heart disease (LHD) by far represents the most common form of PH, accounting for 65-80% of cases. The proper distinction between pulmonary arterial hypertension and PH-LHD may be challenging, yet it has direct therapeutic consequences. Despite recent advances in the pathophysiological understanding and clinical assessment, and adjustments in the haemodynamic definitions and classification of PH-LHD, the haemodynamic interrelations in combined post- and pre-capillary PH are complex, definitions and prognostic significance of haemodynamic variables characterizing the degree of pre-capillary PH in LHD remain suboptimal, and there are currently no evidence-based recommendations for the management of PH-LHD. Here, we highlight the prevalence and significance of PH and RV dysfunction in patients with both HF with reduced ejection fraction (HFrEF) and HF with preserved ejection fraction (HFpEF), and provide insights into the complex pathophysiology of cardiopulmonary interaction in LHD, which may lead to the evolution from a 'left ventricular phenotype' to a 'right ventricular phenotype' across the natural history of HF. Furthermore, we propose to better define the individual phenotype of PH by integrating the clinical context, non-invasive assessment, and invasive haemodynamic variables in a structured diagnostic work-up. Finally, we challenge current definitions and diagnostic short falls, and discuss gaps in evidence, therapeutic options and the necessity for future developments in this context.

Under pressure: pulmonary hypertension associated with left heart disease

Pulmonary hypertension (PH) associated with left heart disease (PH-LHD) is the most common type of PH, but its natural history is not well understood. PH-LHD is diagnosed by right heart catheterisation with a mean pulmonary arterial pressure ≥25 mmHg and a pulmonary capillary wedge pressure >15 mmHg. The primary causes of PH-LHD are left ventricular dysfunction of systolic and diastolic origin, and valvular disease. Prognosis is poor and survival rates are low. Limited progress has been made towards specific therapies for PH-LHD, and management focuses on addressing the underlying cause of the disease with supportive therapies, surgery and pharmacological treatments. Clinical trials of therapies for pulmonary arterial hypertension in patients with PH-LHD have thus far been limited and have provided disappointing or conflicting results. Robust, long-term clinical studies in appropriate target populations have the potential to improve the outlook for patients with PH-LHD. Herein, we discuss the knowledge gaps in our understanding of PH-LHD, and describe the current unmet needs and challenges that are faced by clinicians when identifying and managing patients with this disease.

Pulmonary hypertension due to left heart disease is associated with multiple unmet medical needshttp://ow.ly/TFET8