Pulmonary Hypertension Due to Left Heart Disease-A Practical Approach to Diagnosis and Management

The role of serum sodium in poor prognosis evaluation of pulmonary hypertension associated with left heart disease

BACKGROUND

Previous studies have shown that hyponatremia was strongly associated with a poor prognosis of type 1 pulmonary hypertension, and our team's antecedent studies found that low serum sodium was associated with the severity and the length of hospitalization of pulmonary hypertension associated with left ventricular disease (PH-LHD). However, the relationship between serum sodium and the prognosis of PH-LHD remains unclear. This study aims to determine the clinical value of serum sodium in evaluating poor prognosis in patients with PH-LHD.

METHODS

We successfully followed 716 patients with PH-LHD. Kaplan-Meier was used to plot survival in PH-LHD patients with different serum sodium levels. The effect of serum sodium on poor prognosis was analyzed using a Cox proportional risk model. The trends between patients serum sodium and survival were visualized by restricted cubic spline (RCS).

RESULTS

The survival rates at 1, 2, 3 and 4 years were 52%, 41%, 31% and 31% for the patients with hyponatremia associated with PH-LHD and 71%, 71%, 71% and 54% for the patients with hypernatremia, respectively. The observed mortality rate in the hyponatremia and hypernatremia groups surpassed that of the normonatremic group. The adjusted risks of death (risk ratio) for patients with hyponatremia and hypernatremia were found to be 2.044 and 1.877. Furthermore, the restricted cubic spline demonstrated an L-shaped correlation between serum sodium and all-cause mortality in patients with PH-LHD.

CONCLUSIONS

Abnormal serum sodium level is strongly associated with poor prognosis in PH-LHD. Serum sodium may play an important pathogenic role in PH-LHD occurrence and could be used as a marker to assess the survival in patients.

Correlation analysis between lung ultrasound scores and pulmonary arterial systolic pressure in patients with acute heart failure admitted to the emergency intensive care unit

Background

No convenient, inexpensive, and non-invasive screening tools exist to identify pulmonary hypertension (PH) - left heart disease (LHD) patients during the early stages of the disease course. This study investigated whether different methods of lung ultrasound (LUS) could be used for the initial investigation of PH-LHD.

Methods

This was a single-center prospective observational study which was performed in the Zigong Fourth People's Hospital. We consecutively enrolled patients with heart failure (HF) admitted to the emergency intensive care unit from January 2018 to May 2020. Transthoracic echocardiography and LUS were performed within 24 h before discharge. We used the Spearman coefficient for correlation analysis between ultrasound scores and pulmonary arterial systolic pressure (PASP). Bland-Altman plots were generated to inspect possible bias, and receiver operating characteristic (ROC) curves were calculated to assess the relationship between ultrasound scores and an intermediate and high echocardiographic probability of PH-LHD.

Results

Seventy-one patients were enrolled in this study, with an overall median age of 79 (interquartile range: 71.5-84.0) years. Among the 71 patients, 36 (50.7%) cases were male, and 26 (36.6%) had an intermediate and high echocardiographic probability of PH. All four LUS scores in patients with an intermediate and high probability of PH were significantly higher than in patients with a low probability of PH (P <0.05). The correlation coefficient (r) between different LUS scoring methods and PASP was moderate for the 6-zone (r=0.455, P <0.001), 8-zone (r=0.385, P=0.001), 12-zone (r=0.587, P <0.001), and 28-zone (r=0.535, P <0.001) methods. In Bland-Altman plots, each of the four LUS scoring methods had a good agreement with PASP (P <0.001). The 8-zone and 12-zone methods showed moderately accurate discriminative values in differentiating patients with an intermediate and high echocardiographic probability of PH (P <0.05).

Conclusions

LUS is a readily available, inexpensive, and risk-free method that moderately correlates with PASP. LUS is a potential screening tool used for the initial investigation of PH-LHD, especially in emergencies or critical care settings.

Impact of diastolic pulmonary gradient and pulmonary vascular remodeling on survival after left ventricular assist device implantation and heart transplantation

BACKGROUND

The left ventricular assist devices (LVADs) are increasingly used for advanced heart failure as a bridge to heart transplantation or as a destination therapy. The aim of this study was to investigate the changes of diastolic pulmonary gradient (DPG), pulmonary vascular resistance (PVR) and transpulmonary gradient (TPG) after LVAD implantation and their impact on survival after LVAD and heart transplantation.

RESULTS

A total of 73 patients who underwent LVAD (HeartMate III) implantation between 2016 and 2022 were retrospectively studied. According to pre-LVAD catheterization, 49 (67.1%) patients had DPG < 7 mmHg and 24 (32.9%) patients had DPG ≥ 7 mmHg. The patients with a pre-VAD DPG ≥ 7 mmHg had higher frequencies of right ventricular (RV) failure (p < 0.001), RVAD insertion (p < 0.001), need for renal replacement therapy (p = 0.002), total mortality (p = 0.036) and on-VAD mortality (p = 0.04) with a longer ICU stay (p = 0.001) compared to the patients with DPG < 7 mmHg. During the follow-up period of 38 (12-60) months, 24 (32.9%) patients died. Pre-LVAD DPG ≥ 7 mmHg (adjusted HR 1.83, 95% CI 1.21-6.341, p = 0.039) and post-LVAD DPG ≥ 7 mmHg (adjusted HR 3.824, 95% CI 1.482-14.648, p = 0.002) were associated with increased risks of mortality. Neither pre-LVAD TPG ≥ 12 (p = 0.505) nor post-LVAD TPG ≥ 12 mmHg (p = 0.122) was associated with an increased risk of death. Pre-LVAD PVR ≥ 3 WU had a statistically insignificant risk of mortality (HR 2.35, 95% CI 0.803-6.848, p = 0.119) while post-LVAD PVR ≥ 3 WU had an increased risk of death (adjusted HR 2.37, 95% CI 1.241-7.254, p = 0.038). For post-transplantation mortality, post-LVAD DPG ≥ 7 mmHg (p = 0.55), post-LVAD TPG ≥ 12 mmHg (p = 0.85) and PVR ≥ 3 WU (p = 0.54) did not have statistically increased risks. The logistic multivariable regression showed that post-LVAD PVR ≥ 3 WU (p = 0.013), post-LVAD DPG ≥ 7 mmHg (p = 0.026) and RVF (p = 0.018) were the predictors of mortality after LVAD implantation. Pre-LVAD DPG ≥ 7 mmHg (p < 0.001) and pre-LVAD PVR ≥ 3 WU (p = 0.036) were the predictors of RVF after LVAD implantation.

CONCLUSIONS

Persistently high DPG was associated with right ventricular failure and mortality after LVAD implantation rather than after heart transplantation. DPG is a better predictor of pulmonary vascular remodeling compared to TPG and PVR. Further larger prospective studies are required in this field due to the growing numbers of patients with advanced heart failure, as possible candidates for LVAD implantation, and limitations of heart transplantation.

Group 2 pulmonary hypertension: from diagnosis to treatment

PURPOSE OF REVIEW

Pulmonary hypertension associated with left heart disease (PHLHD) is common and associated with adverse prognosis. Proper diagnosis is critical to avoid inappropriate treatment. Practical approaches to noninvasive diagnosis are available, though invasive hemodynamics including volume loading or exercise are often necessary for definitive diagnosis. Treatment strategies and research in the field is rapidly evolving.

RECENT FINDINGS

Combined pre and post capillary pulmonary hypertension is associated with remodeling of the pulmonary vasculature that is proportional to the severity of the pulmonary hypertension. Even quite mild elevation of pulmonary vascular resistance (PVR), (greater than 2.0 Wood units (WU)) is associated with adverse outcome. Guideline-directed medical therapy (GDMT) for left heart failure has rapidly evolved, including approval of SGLT2 inhibitors for treatment of heart failure with preserved ejection fraction (HFpEF). However, full implementation of GDMT is lagging. Utilization of implanted pulmonary artery pressure monitoring can facilitate patient management in selected patient phenotypes and has been utilized to demonstrate improvement in pulmonary pressures with emerging therapies in HFpEF including SGLT2 inhibitors and sacubitril/valsartan. A variety of shunt devices to create a left-to-right shunt in order to decompress the left heart are available or undergoing clinical trials. There is concern that there could be adverse response to such devices in patients who have even mild elevation of pulmonary vascular resistance. Sleep disordered breathing is common in PHLHD and should be aggressively sought out and treated.

SUMMARY

Even mild elevation in pulmonary vascular resistance is associated with adverse outcome. A systematic approach to diagnosis of PHLHD is essential. Guideline-directed medical therapy for PHLHD prioritizes optimal management of the left heart disease. Pulmonary artery pressure sensors are useful in selected patients.

The future of group 2 pulmonary hypertension: Exploring clinical trials and therapeutic targets

Pulmonary hypertension due to left heart disease (PH-LHD) or group 2 PH is the most common and lethal form of PH, occurring secondary to left ventricular systolic or diastolic heart failure (HF), left-sided valvular diseases, and congenital abnormalities. It is subdivided into isolated postcapillary PH (IpcPH) and combined pre- and post-capillary PH (CpcPH), with the latter sharing many similarities with group 1 PH. CpcPH is associated with worse outcomes and increased morbidity and mortality when compared to IpcPH. Although IpcPH can be improved by treatment of the underlying LHD, CpcPH is an incurable disease for which no specific treatment exists, likely due to the lack of understanding of its underlying mechanisms. Furthermore, drugs approved for PAH are not recommended for group 2 PH, as they are either ineffective or even deleterious. With this major unmet medical need, a better understanding of mechanisms and the identification of effective treatment strategies for this deadly condition are urgently needed. This review presents relevant background of the molecular mechanisms underlying PH-LHD that could translate into innovative therapeutic targets and explores novel targets currently being evaluated in clinical trials.

Therapeutic augmentation of NO-sGC-cGMP signalling: lessons learned from pulmonary arterial hypertension and heart failure

The nitric oxide (NO)-guanylate cyclase (GC)-cyclic guanosine monophosphate (cGMP) pathway plays an important role in cardiovascular, pulmonary and renal function. Phosphodiesterase-5 inhibitors (PDE-5i) inhibit cGMP degradation, whereas both soluble guanylate cyclase (sGC) stimulators and sGC activators directly increase sGC. PDE-5i (e.g. sildenafil, tadalafil) and sGC stimulators (e.g. riociguat, vericiguat) have been extensively used in pulmonary artery hypertension (PAH) and heart failure (HF). PDE-5i have also been used in end-stage HF before and after left ventricular (LV) assist device (LVAD) implantation. Augmentation of NO-GC-cGMP signalling with PDE-5i causes selective pulmonary vasodilation, which is highly effective in PAH but may have controversial, potentially adverse effects in HF, including pre-LVAD implant due to device unmasking of PDE-5i-induced RV dysfunction. In contrast, retrospective analyses have demonstrated that PDE-5i have beneficial effects when initiated post LVAD implant due to the improved haemodynamics of the supported LV and the pleiotropic actions of these compounds. sGC stimulators, in turn, are effective both in PAH and in HF due to their balanced pulmonary and systemic vasodilation, and as such they are preferable to PDE-5i if the use of a pulmonary vasodilator is needed in HF patients, including those listed for LVAD implantation. Regarding the effectiveness of PDE-5i and sGC stimulators when initiated post LVAD implant, these two groups of compounds should be tested in a randomized control trial.