What We Talk About When We Talk About the Wedge Pressure

Pleural effusion in severe aortic stenosis: marker of an adverse haemodynamic constellation and poor prognosis

AIM

Pleural effusion (PE) is a common chest radiography (CXR) finding in patients with advanced cardiac disease. The pathophysiology and clinical value of PE in this setting are incompletely defined. We aimed to assess the haemodynamic correlates and prognostic impact of PE in patients with severe aortic stenosis (AS).

METHODS AND RESULTS

We studied 471 patients (mean age 74 ± 10 years) with severe AS (indexed aortic valve area 0.42 ± 0.12 cm2/m2, left ventricular ejection fraction 58 ± 12%) undergoing right heart catheterization and upright CXR prior to aortic valve replacement (AVR). Two radiologist independently evaluated all CXR for the presence of bilateral PE, unilateral, or no PE, blinded to any other data. There were 49 (10%) patients with bilateral PE, 32 (7%) patients with unilateral PE, and 390 (83%) patients with no PE. Patients with bilateral PE had the highest mean right atrial pressure, mean pulmonary artery wedge pressure (mPAWP), and pulmonary vascular resistance, and had the lowest stroke volume index while those with unilateral PE had intermediate values. In the multivariate analysis, mPAWP was an independent predictor of any PE and bilateral PE. After a median (interquartile range) post-AVR follow-up of 1361 (957-1878) days mortality was highest in patients with bilateral PE (2.7 times higher than in patients without PE), whereas patients with unilateral PE had similar mortality as those without PE.

CONCLUSIONS

In severe AS patients, the presence of PE, particularly bilateral PE, is a marker of a poor haemodynamic constellation. Bilateral PE is associated with a substantially increased post-AVR mortality.

Pulmonary Congestion by Conventional Chest Radiography: Relationship With Hemodynamics and Mortality in Patients With Severe Aortic Stenosis

Background

The relationship between chest radiograph (CXR) findings of pulmonary congestion and invasive hemodynamics and clinical outcomes in patients with cardiac diseases is unclear. We assessed the correlation between a CXR-based congestion score (RxCS) and the mean pulmonary artery wedge pressure (mPAWP) and the prognostic impact of RxCS and mPAWP in severe aortic stenosis (AS).

Methods

In 471 patients with severe AS undergoing right heart catheterization and upright CXR, the RxCS was calculated (6 items, maximum score: 10 points) independently by 2 radiologists (average value taken) blinded to clinical data. Congestion was defined as an RxCS > 1. Four patterns were defined based on the presence or absence of congestion (C+ or C-) and elevated (> 15 mm Hg) or normal mPAWP (P+ or P-).

Results

The median (interquartile range) RxCS was 1 (0-2). Patients with an RxCS > 1 (n = 207) had a higher mean right atrial pressure, mean pulmonary artery pressure, mPAWP, and pulmonary vascular resistance than patients with an RxCS ≤ 1 (n = 264). However, the correlation between the RxCS and the mPAWP was moderate only (r = 0.45). Patients with a C+/P+ pattern had the worst hemodynamics, whereas C-/P- patients had the most favourable constellation. After a median post-valve replacement follow-up of 1361 days, mortality was higher in patients with RxCs > 1 vs ≤ 1 as well as mPAWP > 15 mm Hg vs ≤15 mm Hg. Mortality was highest in C+/P+ patients and lowest in C-/P- patients, whereas it was intermediate in C-/P+ and C+/P- patients.

Conclusions

In AS patients, RxCS and mPAWP have a significant but moderate correlation. Both RxCS and mPAWP provide prognostic information.

Pulmonary Hypertension Associated with Left Heart Disease

Pulmonary hypertension (PH) is a common complication of diseases affecting the left heart, mostly found in patients suffering from heart failure, with or without preserved left ventricular ejection fraction. Initially driven by a passive increase in left atrial pressure (postcapillary PH), several mechanisms may lead in a subset of patient to significant structural changes of the pulmonary vessels or a precapillary component. In addition, the right ventricle may be independently affected, which results in right ventricular to pulmonary artery uncoupling and right ventricular failure, all being associated with a worse outcome. The differential diagnosis of PH associated with left heart disease versus pulmonary arterial hypertension (PAH) is especially challenging in patients with cardiovascular comorbidities and/or heart failure with preserved ejection fraction (HFpEF). A stepwise approach to diagnosis is proposed, starting with a proper clinical multidimensional phenotyping to identify patients in whom hemodynamic confirmation is deemed necessary. Provocative testing (exercise testing, fluid loading, or simple leg raising) is useful in the cath laboratory to identify patients with abnormal response who are more likely to suffer from HFpEF. In contrast with group 1 PH, management of PH associated with left heart disease must focus on the treatment of the underlying condition. Some PAH-approved targets have been unsuccessfully tried in clinical studies in a heterogeneous group of patients, some even leading to an increase in adverse events. There is currently no approved therapy for PH associated with left heart disease.

Pulmonary artery wedge pressure and left ventricular end-diastolic pressure during exercise in patients with dyspnoea

Background

Pulmonary artery wedge pressure (PAWP) during exercise, as a surrogate for left ventricular (LV) end-diastolic pressure (EDP), is used to diagnose heart failure with preserved ejection fraction (HFpEF). However, LVEDP is the gold standard to assess LV filling, end-diastolic PAWP (PAWPED) is supposed to coincide with LVEDP and mean PAWP throughout the cardiac cycle (PAWPM) better reflects the haemodynamic load imposed on the pulmonary circulation. The objective of the present study was to determine precision and accuracy of PAWP estimates for LVEDP during exercise, as well as the rate of agreement between these measures.

Methods

46 individuals underwent simultaneous right and left heart catheterisation, at rest and during exercise, to confirm/exclude HFpEF. We evaluated: linear regression between LVEDP and PAWP, Bland-Altman graphs, and the rate of concordance of dichotomised LVEDP and PAWP ≥ or < diagnostic thresholds for HFpEF.

Results

At peak exercise, PAWPM and LVEDP, as well as PAWPED and LVEDP, were fairly correlated (R2>0.69, p<0.01), with minimal bias (+2 and 0 mmHg respectively) but large limits of agreement (±11 mmHg). 89% of individuals had concordant PAWP and LVEDP ≥ or <25 mmHg (Cohen's κ=0.64). Individuals with either LVEDP or PAWPM ≥25 mmHg showed a PAWPM increase relative to cardiac output (CO) changes (PAWPM/CO slope) >2 mmHg·L-1·min-1.

Conclusions

During exercise, PAWP is accurate but not precise for the estimation of LVEDP. Despite a good rate of concordance, these two measures might occasionally disagree.

Exercise haemodynamics in heart failure with preserved ejection fraction: a systematic review and meta-analysis

AIMS

Exercise right heart catheterization (RHC) is considered the gold-standard test to diagnose heart failure with preserved ejection fraction (HFpEF). However, exercise RHC is an insufficiently standardized technique, and current haemodynamic thresholds to define HFpEF are not universally accepted. We sought to describe the exercise haemodynamics profile of HFpEF cohorts reported in literature, as compared with control subjects.

METHODS AND RESULTS

We performed a systematic literature review until December 2020. Studies reporting pulmonary artery wedge pressure (PAWP) at rest and peak exercise were extracted. Summary estimates of all haemodynamic variables were evaluated, stratified according to body position (supine/upright exercise). The PAWP/cardiac output (CO) slope during exercise was extrapolated. Twenty-seven studies were identified, providing data for 2180 HFpEF patients and 682 controls. At peak exercise, patients with HFpEF achieved higher PAWP (30 [29-31] vs. 16 [15-17] mmHg, P < 0.001) and mean right atrial pressure (P < 0.001) than controls. These differences persisted after adjustment for age, sex, body mass index, and body position. However, peak PAWP values were highly heterogeneous among the cohorts (I²  = 93%), with a relative overlap with controls. PAWP/CO slope was steeper in HFpEF than in controls (3.75 [3.20-4.28] vs. 0.95 [0.30-1.59] mmHg/L/min, P value < 0.0001), even after adjustment for covariates (P = 0.007).

CONCLUSIONS

Despite methodological heterogeneity, as well as heterogeneity of pooled haemodynamic estimates, the exercise haemodynamic profile of HFpEF patients is consistent across studies and characterized by a steep PAWP rise during exercise. More standardization of exercise haemodynamics may be advisable for a wider application in clinical practice.

Hemodynamic Effects of Cyclic Guanosine Monophosphate-Dependent Signaling Through β3 Adrenoceptor Stimulation in Patients With Advanced Heart Failure: A Randomized Invasive Clinical Trial

BACKGROUND

β3-AR (β3-adrenergic receptor) stimulation improved systolic function in a sheep model of systolic heart failure (heart failure with reduced ejection fraction [HFrEF]). Exploratory findings in patients with New York Heart Association functional class II HFrEF treated with the β3-AR-agonist mirabegron supported this observation. Here, we measured the hemodynamic response to mirabegron in patients with severe HFrEF.

METHODS

In this randomized, double-blind, placebo-controlled trial we assigned patients with New York Heart Association functional class III-IV HFrEF, left ventricular ejection fraction <35% and increased NT-proBNP (N-terminal pro-B-type natriuretic peptide) levels to receive mirabegron (300 mg daily) or placebo orally for a week, as add on to recommended HF therapy. Invasive hemodynamic measurements during rest and submaximal exercise at baseline, 3 hours after first study dose and repeated after 1 week's treatment were obtained. Predefined parameters for analyses were changes in cardiac- and stroke volume index, pulmonary and systemic vascular resistance, heart rate, and blood pressure.

RESULTS

We randomized 22 patients (age 66±11 years, 18 men, 16, New York Heart Association functional class III), left ventricular ejection fraction 20±7%, median NT-proBNP 1953 ng/L. No significant changes were seen after 3 hours, but after 1 week, there was a significantly larger increase in cardiac index in the mirabegron group compared with the placebo group (mean difference, 0.41 [CI, 0.07-0.75] L/min/BSA; P=0.039). Pulmonary vascular resistance decreased significantly more in the mirabegron group compared with the placebo group (-1.6 [CI, -0.4 to -2.8] Wood units; P=0.02). No significant differences were seen during exercise. There were no differences in changes in heart rate, systemic vascular resistance, blood pressure, or renal function between groups. Mirabegron was well-tolerated.

CONCLUSIONS

Oral treatment with the β3-AR-agonist mirabegron for 1 week increased cardiac index and decreased pulmonary vascular resistance in patients with moderate to severe HFrEF. Mirabegron may be useful in patients with worsening or terminal HF.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: 2016-002367-34.

Wedge Pressure vs Left Ventricular End-Diastolic Pressure for Pulmonary Hypertension Classification and Prognostication in Severe Aortic Stenosis

BACKGROUND

Differentiation between precapillary and postcapillary pulmonary hypertension (PH) classically relies on mean pulmonary artery wedge pressure (mPAWP). The left ventricular end-diastolic pressure (LVEDP) is proposed as an equivalent alternative. However, mPAWP and LVEDP may differ substantially. We compared the impact of the choice of using the mPAWP vs the LVEDP on PH classification and mortality prediction in patients with severe aortic stenosis (AS) undergoing valve replacement.

METHODS

In 335 patients with severe AS , both mPAWP and LVEDP were measured. A mean pulmonary artery pressure ≥ 25 mm Hg was used to define PH, and either mPAWP or LVEDP was used to differentiate between precapillary and postcapillary PH (≤ 15 vs > 15 mm Hg). Mortality after a median follow-up of 1484 days after aortic valve replacement was assessed.

RESULTS

Overall, mPAWP was lower than LVEDP (16 ± 8 mm Hg vs 21 ± 8 mm Hg; P < 0.001). Among 140 patients (42%) with PH, the PAWP-based classification revealed 76 (54% of those with PH) with isolated postcapillary PH, 48 (34%) with combined pre- and postcapillary PH, and 16 (12%) with precapillary PH. When the LVEDP was used, 59 patients (42%) were differently classified. These patients had higher mortality than those who were not differently classified [hazard ratio 2.79 (95% confidence interval, 1.17-6.65); P = 0.02]. Higher mPAWP was associated with increased mortality [hazard ratio 1.07 (95% confidence interval, 1.03-1.11) per 1 mm Hg; P = 0.001], whereas higher LVEDP was not.

CONCLUSIONS

Use of LVEDP rather than mPAWP results in a divergent PH classification in nearly every second patient with severe AS. These patients have higher mortality after aortic valve replacement. The mPAWP, but not the LVEDP, predicts mortality.

Right ventricular and cyclic guanosine monophosphate signalling abnormalities in stages B and C of heart failure with preserved ejection fraction

Aims

Identifying early right ventricular (RV) dysfunction and impaired vasodilator reserve is challenging in heart failure with preserved ejection fraction (HFpEF). We hypothesized that cardiac magnetic resonance (CMR)‐based exercise imaging and serial cyclic guanosine monophosphate (cGMP) measurements can identify dynamic RV‐arterial uncoupling and responsiveness to pulmonary vasodilators at early stages of the HFpEF syndrome.

Methods and results

Patients with HFpEF (n = 16), impaired left ventricular relaxation due to concentric remodelling (LVCR, n = 7), and healthy controls (n = 8) underwent CMR at rest and during supine bicycle exercise with simultaneous measurements of central haemodynamics and circulating cGMP levels, before and after oral administration of 50 mg sildenafil. At rest, mean pulmonary artery pressures (mPAP) were higher in HFpEF, compared with LVCR and controls (27 ± 2, 18 ± 1, and 11 ± 1, respectively; P = 0.01), whereas biventricular volumes, heart rate, and stroke volume were similar. During exercise, LVCR and HFpEF had a greater increase in the ratio of mPAP over cardiac output than controls (5.50 ± 0.77 and 6.34 ± 0.86 vs. 2.24 ± 0.55 in controls, P = 0.005). The ratio of peak exercise to rest RV end‐systolic pressure‐volume, a surrogate of RV contractility, was significantly reduced in LVCR and HFpEF (2.32 ± 0.17 and 1.56 ± 0.08 vs. 3.49 ± 0.35 in controls, P < 0.001) and correlated with peak exercise VO₂ (R² = 0.648, P < 0.001). cGMP levels increased with exercise across the HFpEF spectrum (P < 0.05 vs. baseline), except when postcapillary pulmonary hypertension was present at rest (P = 0.73 vs. baseline). A single sildenafil administration failed to increase circulating cGMP levels and did not improve RV performance.

Conclusion

Exercise CMR identifies impaired RV‐arterial coupling at an early stage of HFpEF. Circulating cGMP levels phenocopy the haemodynamic spectrum in HFpEF but fail to increase after phosphodiesterase type 5 inhibition, endorsing the need for alternative interventions to increase cGMP signalling in HFpEF.

Hemodynamics Prior to Valve Replacement for Severe Aortic Stenosis and Pulmonary Hypertension during Long-Term Follow-Up

(1) Background: Pulmonary hypertension after aortic valve replacement (AVR; post-AVR PH) carries a poor prognosis. We assessed the pre-AVR hemodynamic characteristics of patients with versus without post-AVR PH. (2) Methods: We studied 205 patients (mean age 75 ± 10 years) with severe AS (indexed aortic valve area 0.42 ± 0.12 cm²/m², left ventricular ejection fraction 58 ± 11%) undergoing right heart catheterization (RHC) prior to surgical (70%) or transcatheter (30%) AVR. Echocardiography to assess post-AVR PH, defined as estimated systolic pulmonary artery pressure > 45 mmHg, was performed after a median follow-up of 15 months. (3) Results: There were 83/205 (40%) patients with pre-AVR PH (defined as mean pulmonary artery pressure (mPAP) ≥ 25 mmHg by RHC), and 24/205 patients (12%) had post-AVR PH (by echocardiography). Among the patients with post-AVR PH, 21/24 (88%) had already had pre-AVR PH. Despite similar indexed aortic valve area, patients with post-AVR PH had higher mPAP, mean pulmonary artery wedge pressure (mPAWP) and pulmonary vascular resistance (PVR), and lower pulmonary artery capacitance (PAC) than patients without. (4) Conclusions: Patients presenting with PH roughly one year post-AVR already had worse hemodynamic profiles in the pre-AVR RHC compared to those without, being characterized by higher mPAP, mPAWP, and PVR, and lower PAC despite similar AS severity.

Current Limitations of Invasive Exercise Hemodynamics for the Diagnosis of Heart Failure With Preserved Ejection Fraction

BACKGROUND

Exercise hemodynamics can differentiate heart failure with preserved ejection fraction (HFpEF) from noncardiac dyspnea. However, respiratory pressure swings may impact hemodynamic measurements, potentially leading to misdiagnosis of HFpEF. Moreover, threshold values for abnormal hemodynamic response indicative of HFpEF are not universally accepted. Thus, we sought to evaluate the impact of respiratory pressure swings on hemodynamic data interpretation as well as the concordance among 3 proposed exercise hemodynamic criteria for HFpEF: (1) end-expiratory pulmonary artery wedge pressure (PAWP_exp) ≥25 mm Hg; (2) PAWP_exp/cardiac output slope >2 mm Hg/L per minute; and (3) respiratory-averaged (avg) mean pulmonary artery pressure >30 mm Hg, total pulmonary resistance_avg >3 WU, PAWP_avg ≥20 mm Hg.

METHODS

Fifty-seven patients with unexplained dyspnea (70% women, 70±9 years) underwent exercise cardiac catheterization. The difference between end-expiratory and averaged hemodynamic values, as well as the concordance among the 3 hemodynamic definitions of HFpEF, were assessed.

RESULTS

End-expiratory hemodynamics measurements were higher than values averaged across the respiratory cycle. During exercise, a larger proportion of patients exceeded the threshold of 25 mm Hg for PAWP_exp rather than for PAWP_avg (70% versus 53%, P<0.01). The concordance of 3/3 HFpEF exercise hemodynamic criteria was recorded in 70% of patients. PAWP_exp/cardiac output slope identified HFpEF more frequently than the other 2 criteria (81% versus 64% to 69%), incorporating over 97% of abnormal responses to the latter. Patients with 3/3 positive criteria had worse clinical, gas-exchange, and hemodynamic profiles.

CONCLUSIONS

Respiratory pressure swings impact on the exercise hemodynamic definitions of HFpEF that provide discordant results in 30% of patients. Equivocal diagnoses of HFpEF might be limited by adopting the most sensitive and inclusive criterion alone (ie, PAWP_exp/cardiac output slope).

[Differential Diagnosis of Pulmonary Hypertension Using the Example of Collagenosis-associated PAH in the Context of Chronic Lung and Left Heart Disease]

Pulmonary hypertension (PH) can be diagnosed in the context of connective tissue diseases (CTD) as well as in elderly patients with multiple comorbidities. A correct clinical differential diagnosis and classification is essential before adequate therapeutic decisions can be made. Differential diagnosis of PH in CTD comprises associated pulmonary arterial hypertension (APAH), group 2 or 3 PH (PH arising from left heart or chronic lung disease), chronic thromboembolic PH (PH) and group 5 (e. g. in the context of terminal renal insufficiency). This is also true of elderly patients in whom the decision has to be made if the increasing number of coincident diseases lead to PH or have to be interpreted as comorbidities. In this manuscript, the differential diagnosis of PH is elucidated, focusing on CTD, in the context of left heart disease and chronic lung disease. Furthermore, criteria are presented facilitating an objective approach in this context.

Non-Invasive Assessment of Pulmonary Vasculopathy

Right heart catheterization remains necessary for the diagnosis of pulmonary hypertension and, therefore, for the prognostic evaluation of patients with chronic heart failure. The non-invaSive Assessment of Pulmonary vasculoPathy in Heart failure (SAPPHIRE) study was designed to assess the feasibility and prognostic relevance of a non-invasive evaluation of the pulmonary artery vasculature in patients with heart failure and pulmonary hypertension. Patients will undergo a right heart catheterization, cardiac resonance imaging, and a pulmonary function test in order to identify structural and functional parameters allowing the identification of combined pre- and postcapillary pulmonary hypertension, and correlate these findings with the hemodynamic data.

Hemodynamic function of the right ventricular-pulmonary vascular-left atrial unit: normal responses to exercise in healthy adults

With each heartbeat, the right ventricle (RV) inputs blood into the pulmonary vascular (PV) compartment, which conducts blood through the lungs at low pressure and concurrently fills the left atrium (LA) for output to the systemic circulation. This overall hemodynamic function of the integrated RV-PV-LA unit is determined by complex interactions between the components that vary over the cardiac cycle but are often assessed in terms of mean pressure and flow. Exercise challenges these hemodynamic interactions as cardiac filling increases, stroke volume augments, and cycle length decreases, with PV pressures ultimately increasing in association with cardiac output. Recent cardiopulmonary exercise hemodynamic studies have enriched the available data from healthy adults, yielded insight into the underlying mechanisms that modify the PV pressure-flow relationship, and better delineated the normal limits of healthy responses to exercise. This review will examine hemodynamic function of the RV-PV-LA unit using the two-element Windkessel model for the pulmonary circulation. It will focus on acute PV and LA responses that accommodate increased RV output during exercise, including PV recruitment and distension and LA reservoir expansion, and the integrated mean pressure-flow response to exercise in healthy adults. Finally, it will consider how these responses may be impacted by age-related remodeling and modified by sex-related cardiopulmonary differences. Studying the determinants and recognizing the normal limits of PV pressure-flow relations during exercise will improve our understanding of cardiopulmonary mechanisms that facilitate or limit exercise.

Pulmonary Artery Wedge Pressure Respiratory Variation Increases With Sodium Nitroprusside Vasodilator Challenge

BACKGROUND

The physiologic factors leading to pulmonary arterial wedge pressure respiratory variation (PAWP_var) are underexplored. We hypothesized that PAWP_var is associated with baseline PAWP and would predict response to sodium nitroprusside (SNP).

METHODS AND RESULTS

We performed a retrospective study of right heart catheterization studies in 51 subjects with SNP challenge at our institution from 2012 to 2019. PAWP_var was defined as expiratory minus inspiratory PAWP. Baseline %PAWP_var was inversely correlated with baseline PAWP (R = -0.5). SNP administration led to increased %PAWP_var (+27%, P < .01). Subjects with low baseline PAWP_var (less than the median) had an increase in PAWP_var with SNP (3 ± 4 mm Hg), whereas those with a high baseline PAWP_var (greater than the median) did not (-0.6 ± 4 mm Hg, P = .003). Those who had a greater than the median PAWP_var increase with SNP had greater cardiac output augmentation compared with those who had less than a median increase in PAWP_var (1.7 ± 1.5 L/min vs 0.9 ± 0.7 L/min, P = .02). An increasing PAWP_var after SNP was associated with significant discrepancy in the number of subjects achieving transplant-acceptable pulmonary vascular resistance (<2.5 Wood units) when calculated by expiratory versus mean PAWP (37 vs 27 subjects, 20% discrepancy rate). Subjects with a higher PAWP_var after SNP were more likely to demonstrate discrepant transplant-acceptable pulmonary vascular resistance calculations comparing expiratory versus mean PAWP than those with lower PAWP_var post-SNP (47% vs 13%, odds ratio 5.5, P = .03).

CONCLUSIONS

Our findings indicate that PAWP_var is a meaningful physiologic parameter that is influenced by the compliance of the left heart/pulmonary vascular system and its relative preload and afterload states.

Critical appraisal of the instantaneous end-diastolic pulmonary arterial wedge pressures

Aims

A substantial shift in the field of pulmonary hypertension (PH) is ongoing, as the previous practice of mean pulmonary arterial wedge pressure (PAWP_M) is no longer supported. Instead, aiming for a better estimate of end‐diastolic pressures (EDP), instantaneous PAWP at mid‐A‐wave (PAWP_mid‐A) or, in the absence of an A‐wave, at 130–160 ms following QRS onset has recently been recommended. Electrocardiogram‐gated PAWP (PAWP_QRS) has also been proposed. The quantitative differences as well as the diagnostic and prognostic utility of these novel PAWP measurements have not been evaluated. We set out to address these issues.

Methods and results

Pressure tracings of 141 patients with PH due to left heart disease (PH‐LHD) and 43 with primary pulmonary arterial hypertension (PAH) were analysed. PAWP was measured as follows: (i) mean pressure (PAWP_M); (ii) per the latest consensus approach [PAWP_mid‐A, or in atrial fibrillation 130, 140, 150, and 160 ms following QRS onset (PAWP_130–160)]; (iii) at QRS onset (PAWP_QRS); and (iv) Z‐point (PAWP_Z). For each PAWP, the corresponding pulmonary vascular resistance (PVR) and diastolic pressure gradient were calculated. The cohort comprised 45% female. Mean age was 66 ± 15. PAWP_mid‐A was in good agreement with PAWP_Z (17.3 [14.5 to 21.2] vs. 17.6 [14.2 to 21.6] mmHg, P = 0.63), whereas PAWP_QRS provided significantly lower values (15.3 [12.5 to 19.2] mmHg, P < 0.001). In atrial fibrillation, PAWP₁₃₀ and PAWP_QRS yielded the optimal temporal and quantitative analyses of EDPs. The ability to differentiate PAH from PH‐LHD was similar for the various PAWP measurements [PAWP_M: area under the curve (AUC) 0.98, confidence interval (CI) 0.96–0.99; PAWP_mid‐A/130: AUC 0.94, CI 0.91–0.98; PAWP_QRS: AUC 0.96, CI 0.94–0.99, P < 0.001 for all]. PVR based on instantaneous PAWP measurements failed to provide superior prognostic information in PH‐LHD as compared with conventional PVR.

Conclusions

Although instantaneous PAWP measurement might better represent EDP, they nevertheless fail to yield incremental diagnostic or prognostic information in PH‐LHD as compared with conventional measurements.

Optimizing diastolic pressure gradient assessment

Aims

The diastolic pressure gradient (DPG) has been proposed as a marker pulmonary vascular disease in the setting of left heart failure (HF). However, its diagnostic utility is compromised by the high prevalence of physiologically incompatible negative values (DPG_NEG) and the contradictory evidence on its prognostic value. Pressure pulsatility impacts on DPG measurements, thus conceivably, pulmonary artery wedge pressure (PAWP) measurements insusceptible to the oscillatory effect of the V-wave might yield a more reliable DPG assessment. We set out to investigate how the instantaneous PAWP at the trough of the Y-descent (PAWP_Y) influences the prevalence of DPG_NEG and the prognostic value of the resultant DPG_Y.

Methods

Hundred and fifty-three consecutive HF patients referred for right heart catheterisation were enrolled prospectively. DPG, as currently recommended, was calculated. Subsequently, PAWP_Y was measured and the corresponding DPG_Y was calculated.

Results

DPG_Y yielded higher values (median, IQR: 3.2, 0.6–5.7 mmHg) than DPG (median, IQR: 0.9, − 1.7–3.8 mmHg); p < 0.001. Conventional DPG was negative in 45% of the patients whereas DPG_Y in only 15%. During follow-up (22 ± 14 months) 58 patients have undergone heart-transplantation or died. The predictive ability of DPG_Y ≥ 6 mmHg for the above defined end-point events was significant [HR 2.1; p = 0.007] and independent of resting mean pulmonary artery pressure (PAP_M). In contrast, conventional DPG did not comprise significant prognostic value following adjustment for PAP_M.

Conclusion

Instantaneous pressures at the trough of Y-descent yield significantly fewer DPG_NEG than conventional DPG and entail superior prognostic value in HF patients with and without PH.

Graphic abstract

Electronic supplementary material

The online version of this article (10.1007/s00392-020-01641-w) contains supplementary material, which is available to authorized users.

Pulmonary hypertension due to left heart disease

Pulmonary hypertension (PH) is frequent in left heart disease (LHD), as a consequence of the underlying condition. Significant advances have occurred over the past 5 years since the 5th World Symposium on Pulmonary Hypertension in 2013, leading to a better understanding of PH-LHD, challenges and gaps in evidence. PH in heart failure with preserved ejection fraction represents the most complex situation, as it may be misdiagnosed with group 1 PH. Based on the latest evidence, we propose a new haemodynamic definition for PH due to LHD and a three-step pragmatic approach to differential diagnosis. This includes the identification of a specific “left heart” phenotype and a non-invasive probability of PH-LHD. Invasive confirmation of PH-LHD is based on the accurate measurement of pulmonary arterial wedge pressure and, in patients with high probability, provocative testing to clarify the diagnosis. Finally, recent clinical trials did not demonstrate a benefit in treating PH due to LHD with pulmonary arterial hypertension-approved therapies.

State of the art and research perspectives in pulmonary hypertension due to left heart disease including diagnostic and treatment insightshttp://ow.ly/vr0I30md6KC

Proximal pulmonary arterial wall disease in patients with persistent pulmonary hypertension after successful left-sided valve replacement according to the hemodynamic phenotype

Regression of pulmonary hypertension (PH) is often incomplete after successful left-sided valve replacement (LSVR). Proximal pulmonary arterial (PPA) wall disease can be involved in patients with persistent-PH after LSVR, affecting the right ventricular to pulmonary arterial (RV-PA) coupling. Fifteen patients underwent successful LSVR at least one year ago presenting PH by echo (> 50 mmHg). Prosthesis-patient mismatch and left ventricular dysfunction were discarded. All patients underwent hemodynamic and intravascular ultrasound (IVUS) study. We estimated PPA stiffness (elastic modulus [EM]) and the relative area wall thickness (AWT). Acute vasoreactivity was assessed by inhaled nitric oxide (iNO) testing. RV-PA coupling was estimated by the tricuspid annular plane systolic excursion to systolic pulmonary arterial pressure ratio. Patients were classified as isolated post-capillary PH (Ipc-PH; pulmonary vascular resistance [PVR] ≤ 3 WU and/or diastolic pulmonary gradient [DPG] < 7 mmHg) and combined post- and pre-capillary PH (Cpc-PH; PVR > 3 WU and DPG ≥ 7 mmHg). Both Ipc-PH and Cpc-PH showed a significant increase of EM and AWT. Despite normal PVR and DPG, Ipc-PH had a significant decrease in pulmonary arterial capacitance and RV-PA coupling impairment. Cpc-PH had worse PA stiffness and RV-PA coupling to Ipc-PH ( P < 0.05). iNO decreased RV afterload, improving the cardiac index and stroke volume only in Cpc-PH ( P < 0.05). Patients with persistent PH after successful LSVR have PPA wall disease and RV-PA coupling impairment beyond the hemodynamic phenotype. Cpc-PH is responsive to iNO, having the worse PA stiffness and RV-PA coupling. The PPA remodeling could be an early event in the natural history of PH associated with left heart disease.

Features Associated With Discordance Between Pulmonary Arterial Wedge Pressure and Left Ventricular End Diastolic Pressure in Clinical Practice: Implications for Pulmonary Hypertension Classification

BACKGROUND

The measurements used to define pulmonary hypertension (PH) etiology, pulmonary arterial wedge pressure (PAWP), and left ventricular end-diastolic pressure (LVEDP) vary in clinical practice. We aimed to identify clinical features associated with measurement discrepancy between PAWP and LVEDP in patients with PH.

METHODS

We extracted clinical data and invasive hemodynamics from consecutive patients undergoing concurrent right and left heart catheterization at Vanderbilt University between 1998 and 2014. The primary outcome was discordance between PAWP and LVEDP in patients with PH in a logistic regression model.

RESULTS

We identified 2,270 study subjects (median age, 63 years; 53% men). The mean difference between PAWP and LVEDP was -1.6 mm Hg (interquartile range, -15 to 12 mm Hg). The two measurements were moderately correlated by linear regression (R = 0.6, P < .001). Results were similar when restricted to patients with PH. Among patients with PH (n = 1,331), older age (OR, 1.77; 95% CI, 1.23-2.45) was associated with PAWP underestimation in multivariate models, whereas atrial fibrillation (OR, 1.75; 95% CI, 1.08-2.84), a history of rheumatic valve disease (OR, 2.2; 95% CI, 1.36-3.52), and larger left atrial diameter (OR, 1.70; 95% CI, 1.24-2.32) were associated with PAWP overestimation of LVEDP. Results were similar in sensitivity analyses.

CONCLUSIONS

Clinically meaningful disagreement between PAWP and LVEDP is common. Atrial fibrillation, rheumatic valve disease, and larger left atrial diameter are associated with misclassification of PH etiology when relying on PAWP alone. These findings are important because of the fundamental differences in the treatment of precapillary and postcapillary PH.

Pulmonary hypertension due to a stiff left atrium: Speckle tracking equivalents of large V-waves

Heart failure with preserved ejection fraction (HFpEF) is a widely heterogeneous clinical condition. Left ventricular diastolic dysfunction is the leading etiology of HFpEF, but there might be patients presenting with a predominant disease of the left atrium (LA). We report a case of HFpEF secondary to a stiff LA, in which we corroborated invasive hemodynamic assessment with LA strain analysis. Pathognomonic, tall V-waves were observed in the wedge position in the absence of mitral regurgitation and with a near-normal QRS-gated, pre-V-wave pressure, indicating that left ventricular diastolic dysfunction was not a major issue in this case. These hemodynamic findings were mirrored by very low LA strain values, compatible with a stiff and noncompliant chamber.

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.