Association of Hyponatremia and Outcomes in Pulmonary Hypertension

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.

Postoperative tolvaptan use in left ventricular assist device patients: The TOLVAD randomized pilot study

PURPOSE

Tolvaptan, a selective vasopressin type-2 antagonist, has been shown to increase serum sodium (Na) and urine output in hyponatremic left ventricular assist device (LVAD) patients in retrospective studies. In this prospective randomized pilot study, we aimed to assess the efficacy of tolvaptan in this population.

METHODS

We conducted a prospective, randomized, non-blinded pilot study of LVAD recipients with post-operative hyponatremia (Na < 135 mEq/L) (NCT05408104). Eligible participants were randomized to receive tolvaptan 15 mg daily in addition to usual care versus usual care alone. The primary outcome was a change in Na level and estimated glomerular filtration rate (eGFR), from the first post-operative day of hyponatremia (the day of randomization) to discharge.

RESULTS

A total of 33 participants were enrolled, and 28 underwent randomization (median age 55 [IQR 50-62]), 21% women, 54% Black, 32% ischemic cardiomyopathy, median baseline Na 135 (IQR 134-138). Fifteen participants were randomized to tolvaptan (TLV) and 13 were randomized to usual care alone (No-TLV). Mean change in Na from randomization to discharge in the TLV group was 2.7 mEq/L (95%CI 0.7-4.7, p = 0.013) and 1.8 (95%CI 0.5-4.0, p = 0.11) in the No-TLV group, though baseline and final Na levels were similar between groups. The mean change in eGFR was 2.6 ml/min/1.73 m2 (95%CI 10.1-15.3, p = 0.59) in TLV versus 7.5 ml/min/1.73 m2 (95%CI 5.2-20.2, p = 0.15) in No-TLV. TLV participants had significantly more urine output than No-TLV patients during their first 24 h after randomization (3294 vs 2155 ml, p = 0.043).

CONCLUSION

TLV significantly increases urine output, with nominal improvement in Na level, in hyponatremic post-operative LVAD patients without adversely impacting renal function.

Risk factors for 30-day readmission in adults hospitalized for pulmonary hypertension

Readmissions for pulmonary hypertension are poorly understood and understudied. We sought to determine national estimates and risk factors for 30-day readmission after pulmonary hypertension-related hospitalizations. We utilized the Healthcare Cost and Utilization Project Nationwide Readmission Database, which has weighted estimates of roughly 35 million discharges in the US. Adult patients with primary International Classification of Disease, Ninth Revision, Clinical Modification diagnosis codes of 416.0 and 416.8 for primary and secondary pulmonary hypertension with an index admission between 2012 and 2014 and any readmission within 30 days of the index event were identified. Predictors of 30-day readmission were identified using multivariable logistic regression with adjustment for covariates. Results showed that the national estimate for Primary Pulmonary Hypertension vs Secondary Pulmonary Hypertension-related index events between 2012 and 2014 with 30-day readmission was 247 vs 2550 corresponding to a national readmission risk estimate of 17% vs 18.3%, respectively. The presence of fluid and electrolyte disorders, renal failure, and alcohol abuse were associated with increased risk of readmission in Primary Pulmonary Hypertension, while factors associated with Secondary Pulmonary Hypertension readmissions included anemia, congestive heart failure, lung disease, fluid and electrolyte disorders, renal failure, diabetes, and liver disease. The median cost of Primary Pulmonary Hypertension admissions and readmissions were $46,132 (IQR: $25,384–$85,647) and $41,604.50 (IQR: $22,481.50–$84,420.50), respectively. The median costs of Secondary Pulmonary Hypertension admissions and readmissions were $34,893 (IQR: $19,670–$66,143) and $36,279 (IQR: $19,059–$74,679), respectively. In conclusion, approximately 19% of Primary Pulmonary Hypertension and Secondary Pulmonary Hypertension hospitalizations result in 30-day readmission, with significant costs accrued during the index hospitalization and readmission. With evolving clinical terminology and diagnostic codes, future study will need to better clarify underlying factors associated with readmissions amongst pulmonary hypertension sub-types, and identify methods and procedures to minimize readmission risk.

General measures and supportive therapy for pulmonary arterial hypertension: Updated recommendations from the Cologne Consensus Conference 2018

In the summer of 2016, delegates from the German Respiratory Society, the German Society of Cardiology and the German Society of Pediatric Cardiology met in Cologne, Germany, to define consensus-based practice recommendations for the management of patients with pulmonary arterial hypertension (PAH). These recommendations were built on the 2015 European Pulmonary Hypertension guidelines aiming at their practical implementation, considering country-specific issues, and including new evidence, where available. To this end, a number of working groups was initiated, one of which was specifically dedicated to general measures (i.e. physical activity/supervised rehabilitation, pregnancy/contraception, elective surgery, infection prevention, psychological support, travel) and supportive therapy (i.e. anticoagulants, diuretics, oxygen, cardiovascular medications, anaemia/iron deficiency, arrhythmias) for PAH. While the European guidelines provide detailed recommendations for the use of targeted PAH therapies as well as supportive care, detailed treatment decisions in routine clinical care may be challenging, and the relevance of supportive care is often not sufficiently considered. In addition, new evidence became available, thus requiring a thorough reevaluation of specific recommendations. The detailed results and recommendations of the working group on general measures and supportive therapy for PAH, which were last updated in the spring of 2018, are summarized in this article.

Is hyponatremia associated with mortality in pulmonary arterial hypertension?

Hyponatremia is associated with poor prognosis in left heart failure and liver disease. Its prognostic role in pulmonary arterial hypertension (PAH) is not well defined. We investigated the association between hyponatremia and one-year mortality in two large cohorts of PAH. This study is a secondary analysis evaluating the association between hyponatremia and one-year mortality in patients treated with subcutaneous treprostinil (cohort 1). The results are validated using a PAH registry at a tertiary referral center (cohort 2). Eight-hundred and twenty patients were enrolled in cohort 1 (mean age = 47 ± 14 years) and 791 in cohort 2 (mean age = 55 ± 15 years). Sodium level is negatively correlated with mean right atrial pressure (r = -0.09, P = 0.018; r = -0.089, P = 0.015 in cohorts 1 and 2, respectively). In unadjusted analyses of cohort 1, the sodium level (as a continuous variable) is associated with one-year mortality (hazard ratio = 0.94; P = 0.035). Hyponatremia loses its significance (as a continuous variable and when dichotomized at ≤ 137 mmol/L; P = 0.12) when adjusted for functional class (FC), which is identified as the variable whose presence turns the effect of sodium level into non-significant. Secondary analyses using a cut-off value of < 135 mmol/L showed similar results. These results are validated in cohort 2. Although the sample size for patients with sodium < 130 mmol/L is small (n = 31), severe hyponatremia is associated with higher overall mortality (47% versus 23%; P = 0.01), even when adjusting for age, FC, and baseline 6-min walk distance ( P < 0.001). Although baseline hyponatremia is associated with one-year mortality, it loses its significance when adjusted for FC.

Serum Chloride Levels Track With Survival in Patients With Pulmonary Arterial Hypertension

BACKGROUND

Serum chloride is an important homeostatic biomarker in left heart failure, with significant prognostic implications. The impact of serum chloride in the long-term survival of patients with pulmonary arterial hypertension (PAH) is unknown. We tested whether serum chloride levels are associated with long-term survival in patients with PAH.

METHODS

We included patients with idiopathic or heritable PAH who had a basic metabolic panel performed at the time of their diagnostic right heart catheterization. Laboratory results were recorded both at diagnosis and 6-month follow-up.

RESULTS

We included 277 patients, mean age 51 ± 18 years and 73% women, of whom 254 had a follow-up electrolyte determination at 6 months. Serum chloride was 102.9 ± 3.9 mM/L at diagnosis. A serum chloride ≤ 100 mM/L was noted in 65 (24%) and 53 (21%) patients at diagnosis and 6 months, respectively. Patients with serum chloride ≤ 100 mM/L at 6 months tracked with increase mortality when adjusted by age, sex, pulmonary vascular resistance, diuretics or prostacyclin analogs usage, and serum creatinine and sodium at 6 months (hazard ratio, 1.83; 95% CI, 1.11-3.00). This group of patients was older, with decreased functional capacity, had worse renal function, took more diuretics, had higher pulmonary artery wedge pressure but lower mean pulmonary artery pressure, transpulmonary gradient, and pulmonary vascular resistance.

CONCLUSIONS

Serum chloride at 6 months from the PAH diagnosis is a strong and independent predictor of mortality in patients with idiopathic or heritable PAH, even after adjusting serum sodium, renal function, diuretic, and prostacyclin analog usage.

Impact of pre-procedural hyponatremia on clinical outcomes after transcatheter aortic valve replacement: A propensity-matched analysis

BACKGROUND

Hyponatremia is associated with the increased risk of early and late mortality in patients with cardiac disease. This study aimed to assess the prognostic value of hyponatremia in patients who had undergone transcatheter aortic valve replacement (TAVR).

METHODS

We investigated 1,215 consecutive patients (mean age: 84.4 ± 5.0 years) who underwent TAVR using data from the Optimized CathEter vAlvular iNtervention (OCEAN)-TAVR Japanese multicenter registry. Hyponatremia was defined as a serum sodium value less than 135 mEq/L. The baseline characteristics, procedural outcomes, all-cause, cardiovascular, and non-cardiovascular mortality were compared between patients with hyponatremia (n = 106, 8.7%) and without hyponatremia (n = 1,109, 91.3%). A propensity-matching analysis was used to adjust for the non-uniform patient characteristics.

RESULTS

Differences in the baseline characteristics were observed between the two groups regarding the prevalence of pulmonary disease (37.7% vs. 28.9%, P = 0.04) and the performance of non-elective TAVR (10.4% vs. 4.2%, P = 0.01), although these were minimized in the matched model. The 30-day mortality rates differed between the two groups (7.6% vs. 1.4%, P < 0.001). During a mean follow-up of 330 days, the all-cause and cardiovascular mid-term mortality were higher in the hyponatremia group than in the non-hyponatremia group (log-rank test: P = 0.0047, and P < 0.001, respectively). The three findings above were not attenuated in the propensity-matched model (P < 0.001, P = 0.0044, and P = 0.014, respectively). In contrast, there was no difference in non-cardiovascular mortality between the two groups in both the overall and matched model (P = 0.40 and P = 0.13, respectively).

CONCLUSIONS

Pre-procedural hyponatremia may be a useful marker for predicting early and mid-term clinical outcomes after TAVR.

Increased mortality from complications of pulmonary hypertension in patients undergoing transcatheter aortic valve replacement

Aortic stenosis (AS) leads to pulmonary hypertension (PH) and right ventricle (RV) failure. Our goal was to describe mortality related to postoperative complications in PH patients undergoing transcatheter aortic valve replacement (TAVR). Ninety-three TAVR patients were analyzed (controls, sPAP < 50 mmHg; cases, sPAP ≥ 50 mmHg). Significant findings in cases included increased mortality (365 days), post-TAVR atrioventricular block (AVB) and acute kidney injury (AKI), and increased mean length of stay (LOS). This novel study highlights complications of PH as independent risk factors for death and significant morbidity post TAVR. Optimization of preoperative volume status and RV afterload reduction, while addressing AVB and AKI, may play a vital role in reducing mortality and LOS.

Dehydration in the Elderly: A Review Focused on Economic Burden

BACKGROUND

Dehydration is the most common fluid and electrolyte problem among elderly patients. It is reported to be widely prevalent and costly to individuals and to the health care system. The purpose of this review is to summarize the literature on the economic burden of dehydration in the elderly.

METHOD

A comprehensive search of several databases from database inception to November 2013, only in English language, was conducted. The databases included Pubmed and ISI Web of Science. The search terms «dehydration» / "hyponaremia" / "hypernatremia" AND «cost» AND «elderly» were used to search for comparative studies of the economic burden of dehydration. A total of 15 papers were identified.

RESULTS

Dehydration in the elderly is an independent factor of higher health care expenditures. It is directly associated with an increase in hospital mortality, as well as with an increase in the utilization of ICU, short and long term care facilities, readmission rates and hospital resources, especially among those with moderate to severe hyponatremia.

CONCLUSIONS

Dehydration represents a potential target for intervention to reduce healthcare expenditures and improve patients' quality of life.

Pulmonary hypertension in heart failure with preserved ejection fraction

In heart failure with preserved ejection fraction (HFpEF), an entity that remains challenging and difficult to treat, the development of pulmonary hypertension (PH), via an increase in left atrial pressure, is the direct consequence of reduced relaxation and enhanced stiffness of the left ventricle and is now viewed as an important contributor to clinical worsening and increased mortality. PH becomes a relevant clinical phenotype in approximately 50% of patients with HFpEF and represents a true challenge in the clinical follow-up and management of these patients. Along with these epidemiologic insights, there has been increasing recognition of the pathophysiology of PH and its consequences on the right ventricle in patients with HFpEF. Novel and effective therapeutic interventions aimed at preventing and reversing PH are highly relevant in the attempt to modify the poor clinical trajectory and growing health care burden of HFpEF. Many theoretical rationales as well as progressively accumulating evidence support the usefulness of nitric oxide pathway-potentiating compounds in targeting the lung vasculature through phosphodiesterase 5 inhibitors or guanylate cyclase stimulators to produce vasodilation and potentially a biologic effect. These pharmacologic strategies may be clinically effective options for the treatment of PH in patients with HFpEF; however, large controlled trials are necessary to address definitively the safety, tolerability, and potential impact on morbidity and mortality. This review details the pathophysiologic process, prevalence, and consequences of HFpEF-associated PH and discusses current and emerging treatment strategies to prevent or treat this deleterious sequela when present.

Pathophysiology and clinical relevance of pulmonary remodelling in pulmonary hypertension due to left heart diseases

Pulmonary hypertension (PH) in left heart disease, classified as group II, is the most common form of PH that occurs in approximately 60% of cases of reduced and preserved left ventricular ejection fraction. Although relatively much is known about hemodynamic stages (passive or reactive) and their consequences on the right ventricle (RV) there is no consensus on the best hemodynamic definition of group II PH. In addition, the main pathways that lead to lung capillary injury and impaired biology of small artery remodelling processes are largely unknown. Typical lung manifestations of an increased pulmonary pressure and progressive RV-pulmonary circulation uncoupling are an abnormal alveolar capillary gas diffusion, impaired lung mechanics (restriction), and exercise ventilation inefficiency. Of several classes of pulmonary vasodilators currently clinically available, oral phosphodiesterase 5 inhibition, because of its strong selectivity for targeting the cyclic guanosine monophosphate pathway in the pulmonary circulation, is increasingly emerging as an attractive opportunity to reach hemodynamic benefits, reverse capillary injury, and RV remodelling, and improve functional capacity. Guanylate cyclase stimulators offer an additional intriguing opportunity but the lack of selectivity and systemic effects might preclude some of the anticipated benefits on the pulmonary circulation. Future trials will determine whether new routes of pharmacologic strategy aimed at targeting lung structural and vascular remodelling might affect morbidity and mortality in left heart disease populations. We believe that this therapeutic goal rather than a pure hemodynamic effect might ultimately emerge as an important challenge for the clinician.