Is pulmonary artery wedge pressure a reliable surrogate of left ventricular end-diastolic pressure during exercise for diagnosing HFpEF in patients with unexplained dyspnea?

Background

Left ventricular end-diastolic pressure (LVEDP) is the gold-standard for the assessment of LV filling pressure. For practical reasons, pulmonary artery wedge pressure (PAWP) is used as a surrogate for LVEDP. However, the interposition of the left atrium (LA) may account discrepancies between LVEDP and PAWP. The imprecision of both end-diastolic (or mid-A) and mean PAWP estimates for LVEDP has been widely described for cardiac catheterization at rest. PAWP measurement during exercise has been advocated to discriminate heart failure with preserved ejection fraction (HFpEF) from non-cardiac dyspnea, with an end-expiratory pathologic threshold ≥25 mmHg. However, a formal comparison of PAWP (either mid-A or mean PAWP) vs LVEDP during exercise has never been performed.

Aim

To compare LVEDP and PAWP during exercise.

Methods

We retrospectively analyzed consecutive patients with unexplained dyspnea and a normal LV ejection fraction, who had a clinical indication of right and left heart catheterization at rest and during exercise to assess unexplained dyspnea. Patients with mitral regurgitation ≥ moderate were excluded. Hemodynamic measurements were always taken at end-expiration.

Results

Forty-six consecutive patients were included in the analysis (80% with a peak mean PAWP ≥25 mmHg). We found a good correlation between both mid-A and mean PAWP on one side, and LVEDP on the other side (R2>0.55). At peak exercise, mid-A PAWP had no bias as compared with LVEDP, while mean PAWP slightly overestimated LVEDP by 1–2 mmHg. However, confidence intervals were quite large (Figure 1), suggesting imprecision of PAWP estimates for LVEDP in the individual patient. A disagreement between mean PAWP and LVEDP, using a threshold of ≥25 mmHg for both variables at peak exercise, was found in 11% of patients. In 4% of them, mean PAWP was ≥25 but LVEDP <25 mmHg, due to the appearance of tall V waves in the PAWP position (LA stiffness), increasing PAWP above LVEDP. In the remaining 7%, LVEDP was ≥25 but PAWP <25 mmHg. The latter patients, in whom HFpEF would have not been diagnosed based on peak PAWP alone, showed a PAWP increase during exercise relative to cardiac output changes (PAWP/CO slope) >2 mmHg/L/min, as an alternative parameter suggesting HFpEF.

Conclusions

In patients with unexplained exertional breathlessness, both mid-A and mean PAWP showed good correlation with LVEDP during exercise with minimal average bias, but their ability to estimate LVEDP was burdened by a relevant imprecision. Therefore, when in these patients peak PAWP is <25 mmHg, its assessment might need to be complemented by additional measurements (including LVEDP or PAWP/CO slope) to maximize the diagnostic power of exercise cardiac catheterization in identifying HFpEF.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship.

Right heart adaptation during exercise in pulmonary arterial hypertension and in pulmonary hypertension due to heart failure with preserved ejection fraction

Background

Right heart failure (RHF) represents the final step of distinct diseases, such as pulmonary arterial hypertension (PAH) and pulmonary hypertension (PH) due to heart failure with preserved ejection fraction (HFpEF). RHF may be defined by the inability of the heart to maintain a normal cardiac output (CO) or to do so at the expense of high right atrial pressure (RAP), at rest or during exercise.

However, exercise hemodynamic features suggestive of RHF, as well as their determinants, have still not been defined.

Aim

We sought to i. define the limits of normal of RAP increase during exercise; ii. describe the behavior of RAP during exercise in PAH and in PH-HFpEF, and its relation to right heart afterload and preload.

Methods

We retrospectively analyzed data from consecutive patients referred for suspicion of PH, who underwent both a resting and exercise right heart catheterization at two centers with identical methodology. We included patients with PH-HFpEF or PAH. Right heart adaptation to exercise was described either using absolute or CO-normalized RAP increase during exercise (RAP/CO slope), this latter representing the inverse of the Frank-Starling reserve. A control cohort of subjects with normal hemodynamics at rest and during exercise served to define abnormal increase in RAP, i.e. values of RAP and RAP/CO slope > mean ± 2 standard deviation of controls.

Estimated stressed blood volume (eSBV), as a measure of effective preload, was computed using a commercially-available software.

Results

80 patients were included in the analysis, of which 29 were PH-HFpEF, 30 PAH and 21 controls.

HFpEF patients were older than PAH patients and with a higher burden of cardiovascular comorbidities (p<0.05). Sex representation, BMI, and NTproBNP values were similar in the two groups.

Mean pulmonary artery pressure (PAP), pulmonary vascular resistance (PVR) and total vascular resistance (TPR) were higher in PAH than in PH-HFpEF both at rest and during exercise (p<0.01), in spite of similar CO (Table 1). At rest, eSBV did not differ between HFpEF and PAH, but it was higher in HFpEF at peak exercise.

On average, PH-HFpEF had higher resting and peak RAP than PAH, as well as higher RAP/CO slope (Figure 1).

The upper limit of normal of exercise RAP and of RAP/CO slope, as determined in control subject, was 12 mmHg and 1.55 mmHg/L/min. A higher rate of HFpEF patients, compared with PAH, had a RAP/CO slope and a peak RAP above normal limits (78% and 91% of PH-HFpEF vs 47% and 44% of PAH, respectively, p<0.001).

RAP/CO slope in the whole cohort was associated with eSBV but not with right ventricular afterload measures (PAP, TPR, PVR).

Conclusions

PH-HFpEF display more frequently a steeper increase of RAP during exercise than PAH patients in spite of similar CO, suggesting a more exhausted Frank-Starling reserve. The steep RAP increase during exercise seems to reflect a dysfunctional preload rather than an afterload-mismatch.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship.

An updated meta-analysis of hemodynamics markers of prognosis in patients with pulmonary hypertension due to left heart disease

Background

Pulmonary hypertension (PH) is associated with a poor prognosis in patients with left heart disease (LHD). Several hemodynamic variables have been shown to predict outcome, including pulmonary vascular resistance (PVR), pulmonary artery compliance (PAC), and the diastolic pressure gradient (DPG). We sought to provide an updated analysis on the association of these variables with prognosis in PH-LHD.

Methods

We performed a systematic literature review including studies reporting association measurements between DPG and/or PVR and/or PAC and death in PH-LHD patients. These hemodynamic variables were extracted to estimate the pooled hazard ratio (HR) of adverse outcome for each one, and cumulative meta-analysis was performed to investigate temporal trends in the effects reported in the literature as well as the impact of sample size.

Results

17 articles were identified, including 9716 patients with LHD, heterogeneous in terms of age, sex, and etiology of cardiac disease. In this large population, we found that PVR (HR, 1.09; 95% CI: 1.06–1.12), DPG (HR, 1.02; 95% CI: 1.01–1.02) and PAC (HR, 0.73; 95% CI: 0.76–0.81) were associated with an increased risk of adverse outcome, albeit with a less solid performance of DPG (Figure 1). Similar results were found when hemodynamic variables were analyzed according to the thresholds commonly applied in clinical practice, or subdividing cohorts according to the underlying LHD (either heart failure with preserved or reduced left ventricular ejection fraction, or valvular heart disease). Furthermore, cumulative metanalysis indicated that these results are consistently stable since 2018 (Figure 2).

Conclusions

Despite the heterogeneity of PH-LHD group and the intrinsic limitations of each variable, PVR, DPG, and PAC have an established prognostic value in PH-LHD. The strongest correlation with PVR and PAC supports their use in defining disease severity and identifying a subgroup of patients at higher risk of adverse outcome. We believe that these results are consistent through the years and unlikely to change with the addition of further studies.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship.

A meta-analysis of exercise hemodynamics in heart failure with preserved ejection fraction: the relevance of PAWP/CO slope

Background

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 hemodynamic thresholds to define HFpEF are not universally accepted. We sought to describe the exercise hemodynamics profile of HFpEF cohorts reported in literature, as compared with control subjects.

Methods

We performed a systematic literature review following the PRISMA statement until December 2020. Studies reporting pulmonary artery wedge pressure (PAWP) at rest and peak exercise were extracted. Summary estimates of all hemodynamic variables were evaluated, stratified according to body position (supine/upright exercise). The PAWP / cardiac output (CO) slope during exercise was extrapolated.

Results

Twenty-seven studies were identified, providing data for 2180 HFpEF patients and 682 controls. At peak exercise, HfpEF cohorts showed a summary estimate of PAWP at peak which was twice as high as compared with control cohorts (30; 95% CI: 29–31 mmHg and 16; 95% CI: 15–17 mmHg, respectively), as well as of delta PAWP (15; 95% CI: 14–16 mmHg and 7; 95% CI: 6–8 mmHg, respectively), and of right atrial pressure (18; 95% CI: 16–19 mmHg and 8; 95% CI: 8–9 mmHg, respectively). These differences persisted after adjustment for age, sex, body mass index, body position. Additionally, summary estimates of PAWP at peak performed during supine exercise was slightly higher than that obtained in upright position only for HFpEF cohorts (supine position: 31; 95% CI: 30–32 mmHg vs upright position; 26; 95% CI: 25–27 mmHg, respectively, p-value<0.01). However, peak PAWP values were highly heterogeneous among the cohorts (I2=93%), with a relative overlap with controls (Figure 1). HFpEF had a significantly larger impairment in the hemodynamic response to exercise, witnessed by a steeper summary PAWP/CO slope than controls (3.75; 95% CI: 3.20–4.28 mmHg/L/min and 0.95; 95% CI: 0.30–1.59 mmHg/L/min, p-value <0.0001), even after adjustment for covariates (p=0.007) (Figure 2). Finally, summary estimates of PAWP/CO slope were higher in HFpEF cohorts performing exercise in the supine position compared with those in upright position (p<0.0001 and p=0.0002 at non-adjusted and adjusted analysis, respectively), but not in control cohorts (p=0.135 and p=0.966 at non-adjusted and adjusted analysis, respectively).

Conclusions

Despite methodological heterogeneity across centers, the hemodynamic profile of HFpEF patients is consistent across studies and characterized by a higher left and right filling pressure at rest compared with controls, enhanced by physical exercise. A PAWP/CO slope cut-off >2 mmHg/L/min seems to retain validity also for studies conducted in the supine position, potentially overcoming the need of different supine and upright PAWP cut-offs.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship.

P284 THE RIGHT HEART ADAPTATS TO EXERCISE MORE EFFICIENTLY IN PULMONARY ARTERIAL HYPERTENSION THAN IN PULMONARY HYPERTENSION DUE TO HEART FAILURE WITH PRESERVED EJECTION FRACTION

Background

Right heart failure (RHF) represents the final step of distinct diseases, differently involving the pulmonary circulation, such as pulmonary arterial hypertension (PAH) and pulmonary hypertension (PH) due to heart failure with preserved ejection fraction (HFpEF). Exercise may unmask right heart maladaptation as a sign of RHF, but cut–offs for right atrial pressure (RAP) rise during exercise remain to be defined. We hypothesized that PH–HFpEF may present with worse right heart adaptation to exercise than PAH due to increased chamber stiffness and dysfunctional preload.

Aim

We sought to describe the behavior of RAP during exercise in PAH and in PH–HFpEF, and the mechanisms underlying right heart maladaptation.

Methods

We performed a retrospective analysis of data (2007–2021) obtained from patients with either PAH or PH–HFpEF who underwent a right heart catheterization at rest and during exercise. Right heart adaptation to exercise was described using either absolute or cardiac output (CO)–normalized RAP increase during exercise (RAP/CO slope). Patients with non–cardiac dyspnea (NCD) served to define RAP limits of normality. Estimated stressed blood volume (eSBV), as a measure of effective preload, was computed based on hemodynamics using a commercially–available software.

Results

Ninety–four patients were included (32 PH–HFpEF, 32 PAH and 30 NCD). The upper limit of normal for absolute peak RAP and RAP/CO slope were 12 mmHg and 1.55 mmHg/L/min. Compared with PH–HFpEF, PAH patients showed higher systolic, diastolic and mean pulmonary artery pressure (PAP) as well as higher indices of right ventricular afterload both at rest and during exercise, but lower filling pressures and similar CO (Figure 1).In particular, PH–HFpEF had higher peak RAP and higher RAP/CO slope than PAH (Figure 1,2). Additionally, 78% and 91% of PH–HFpEF, as compared with 47% and 44% of PAH had a RAP/CO slope and a peak RAP above normal, respectively (p < 0.001). PH–HFpEF presented with higher increase in eSBV, and higher peak eSBV values than PAH (p < 0.05), despite similar resting levels. RAP/eSBV slope was upward shifted (at a given effective preload, RAP was higher) while CO/eSBV slope was flatter (at a given effective preload, CO was lower) in PH–HFpEF as compared with PAH (Figure 3).

Conclusions

PH–HFpEF display worse right heart maladaptation to exercise than PAH, likely due to a combination of increased right heart stiffness and a more exhausted Frank–Starling reserve.

Effort perception and hemodynamic responses to the 3/7 vs. 3X9 methods in heart failure and in coronary artery disease patients: a randomized-cross-over study

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): Fonds Erasme pour la recherche médicale

Background/Introduction

The hemodynamic response to strength training depends on the intensity, the time of rest between exercise sets and the duration of the exercise (1-3). A new method (the ‘3/7 method’), which consist of 5 successive sets of exercise with an increasing number of repetitions (3 to 7) separated by brief inter-set rest intervals (15 s), achieved a greater and faster strength gain after 12 weeks of training in young healthy subjects (4-5) (Fig 1). Further characterization of the tolerability of 3/7 method, as well as rise in blood pressure (BP) and heart rate (HR) it may induce, is needed in a patient population before this methodology can be applied in cardiac rehabilitation centers (6). These parameters were compared to those induced by 3 series of 9 repetitions (‘3X9 method’) with a longer inter-set rest interval (1min), using a randomized and cross-over study design.

Purpose

This study investigated the Borg scale and hemodynamic response of the 3/7 vs. 3X9 strength training methods in heart failure patients with reduced ejection fraction (HFrEF, Left ventricular ejection fraction (LVEF) < 40%) and patients with coronary artery disease (LVEF> 40%, CAD).

Method

23 HFrEF (58±9 y, 13% female) and 22 CAD (64±10 y, 14% female) participated in the study. CAD underwent revascularization between 1 and 6 months prior to the study. Patients with decompensated heart failure, atrial fibrillation, major orthopedics disabilities were not included in the study. The strength training consisted in leg extension against a load of ~ 70% of 1 repetition maximal (1RM). Perceived exertion was also assessed at the end of the last set by using the modified Borg Scale (0-10). HR and BP were assessed noninvasively beat by beat (Task Force Monitor). We compared baseline and peak exercise values in each group. All participants signed an agreement form approved by the local Ethic Review Board.

Result

Baseline BP and HR and effort perception at the end of exercise did not differ between the 3/7 and 3X9 groups (Borg scale: HFrEF 3/7 method: 5,4±2,6 vs. 3X9 method: 5,8±2,5; CAD 3/7 method: 6,2±1,3 vs. 3X9 method: 6,1±1,5; p= NS) (Fig 2). HR became faster with the 3/7 method as compared to the 3X9 method in the HFrEF (85±11 vs. 83±12 bpm, p=0.014, respectively) and CAD (90±13 vs. 87±14 bpm, p=0.03, respectively) patients. In the CAD group, systolic BP increased more with the 3/7 method than with the 3X9 method (143±22 vs. 133±20 mm Hg, p<0.001). Other parameters did not differ.

Conclusion

The 3/7 and 3X9 strength training protocols elicit comparable effort perception and similar hemodynamic responses in HFrEF and CAD. The 3/7 method increases transiently HR by a few more beats in both groups and raises systolic BP by 10 additional mmHg in CAD patients. Taken together, this study suggests the 3/7 method is safe in patients with HFrEF and CAD, and warrants further investigation of the usefulness of the 3/7 method in cardiac rehabilitation units.

Early‐onset and severe Pulmonary Arterial Hypertension due to a novel compound heterozygous association of rare VHL mutations: a case report and review of existing data

Very rare cases of pulmonary arterial hypertension (PAH) have been linked to homozygous or compound heterozygous von Hippel–Lindau (VHL) tumor suppressor gene mutations, while heterozygous VHL mutations lead to VHL tumor syndrome. Although those entities are defined, the genotype–phenotype correlation is incompletely understood, and patient management recommendations are lacking. Here, we describe a case of severe early‐onset PAH due to a so‐far unreported compound heterozygous association of VHL mutations and review the existing data.

Validation of the EUROMACS right-sided heart failure risk score in left ventricular assist device patients: a single center experience

Background

Right Heart failure (RHF) is a severe complication after left ventricular assist device (LVAD) implantation, increasing early and late mortality. A simple 5-item score, the EUROMACS-RHF risk score, was developed to predict early RHF and mortality after implantation.

Purpose

The aim of the study was to investigate whether EUROMACS-RHF risk score was applicable in a single center to predict early (<30 days) post-operative RHF.

Methods

From February 2011 to October 2019 all LVAD implanted patients in our institution were retrospectively reviewed. Only patients with complete data for risk score calculation and RHF analysis were included. Baseline characteristics and hospitalization data, including preoperative clinical, biological, echocardiographic and hemodynamic data were obtained. Based on these informations, EUROMACS-RHF risk score was calculated and classified in low, intermediate and high.

The link between the EUROMACS-RHF risk score and early severe RHF was investigated using Pearson's exact chi-square tests.

Results

The analysis included 88 patients (67 males; 49±2 years). Etiology of HF was ischemic in 36 patients (41%), dilated cardiomyopathy in 21 (24%) and others causes in 31 (35%). A Heart Ware LVAD (94%) was implanted as bridge to transplantation in 96% of the patients; 81 patients (90%) had severe INTERMACS (1–3) profile.

RHF was identified in 21 patients (24.1%), of which 15 (18%) were treated with inotropes for ≥14 days, 8 (9%) had an RVAD, and 11 (13%) were treated with inhaled NO for ≥48 hours. Patients with severe RHF had a significantly longer length of ICU stay compared to patients without (median 20 days versus 6,5 days). The early (<30 days) post-operatory mortality was of 43% (n=9/21) in the RHF group and 6% (n=4/69) in patients without RHF (p<0.001). Three of the twelve patients alive in the RHF group had an emergency transplant.

The prediction of RHF from the EUROMACS-RHF risk score and the observed severe RHF are presented in the table. A high preoperative EUROMACS-RHF score was able to predict the presence of RHF in 52% of patients (p=0.005), while a low score predicted the absence of RHF in 52% of patients (p<0.001). In contrast, an intermediate EUROMACS risk score was not found to predict early RHF (p=0.283).

Conclusion

In our cohort, the EUROMACS-RHF risk score was effective in predicting early severe RHF, in particular for patients with preoperatory low (no RHF) and high (RHF) scores. This external validation confirms the clinical usefulness in risk prediction before LVAD implantation.

Figure 1

Funding Acknowledgement

Type of funding source: None

P4685Validation of noninvasive pulmonary artery pressure/flow relationship: echocardiography vs right heart catheterization

Background

Invasive pressure-flow (P/Q) relationship of the pulmonary circulation can detect the presence of pulmonary hypertension (PH) during exercise and provide information on patients' symptoms and assess disease severity. Doppler-echocardiography was reported to provide accurate but imprecise noninvasive estimates of both resting and exercise pulmonary haemodynamics. However, data on the direct comparison of invasive vs noninvasive approaches to build pressure-flow relationship are scarce.

Purpose

To compare echocardiographic estimates with invasive measurements of P/Q relationship of the pulmonary circulation during exercise.

Methods

Patients undergoing a clinically indicated right heart catheterization and echocardiography were studied at rest and during exercise. The ratio between mean pulmonary artery pressure and cardiac output at peak exercise (TPR), as well as P/Q slope throughout exercise were calculated. Both TPR and P/Q slope are abnormal when ≥3 mmHg/L/min. Echocardiographic estimates were compared with invasive measurements.

Results

Sixty patients were included (mean age 65±14 years, 73% female). PH was present at rest in 38 cases (63%), of precapillary origin in 23 (61%). Heart failure with preserved ejection fraction was diagnosed in 23 patients, of which 17 had no PH at rest. TPR at peak exercise and P/Q slope were abnormal (≥3 mmHg/L/min) in the majority of patients (56 and 45 subjects, respectively).

Echocardiographic estimates of P/Q slope and TPR correlated significantly although weakly with invasive measurements (R2=0.38 and 0.56, respectively, p<0.001). Bias of echocardiography for P/Q slope and TPR was 1.1±4.2 and 0.4±2.9 mmHg/L/min, respectively (figure). Sensitivity of echocardiography to detect an abnormal TPR or P/Q slope (i.e. ≥3 mmHg/L/min) was 100 and 98%, respectively, faced by low specificity (0 and 33%, respectively).

Figure 1

Conclusions

Doppler-echocardiography can provide rather accurate and sensitive but imprecise estimates of pressure-flow relationships of the pulmonary circulation during exercise. This intrinsic imprecision may limit its use in clinical practice.