Improvement of apparently fixed pulmonary hypertension with cardiac resynchronization therapy

Pulmonary hypertension due to left heart disease with pulmonary arterial wedge pressure ≤15 mm Hg

BACKGROUND

Pulmonary hypertension due to left heart disease (PH-LHD) is the most prevalent type of pulmonary hypertension (PH). The hemodynamic diagnostic standard of pulmonary arterial wedge pressure (PAWP) >15 mm Hg that is traditionally recommended by guidelines is being challenged.

METHODS

To address this problem, we analyzed the data of 154 patients with PH-LHD admitted to our center from April 2013 to March 2018. Pharmacological or nonpharmacological treatment of underlying left heart disease was offered to all 154 patients.

RESULTS

In total, there were 24 patients (15.6%) with PAWP ≤15 mm Hg. Comparison of echocardiography and right heart catheterization parameters between the two groups (PAWP >15 mm Hg and PAWP ≤15 mm Hg) showed that the group with PAWP ≤15 mm Hg had smaller left ventricular diameter, higher cardiac output, lower pressure and higher oxygen saturation in the pulmonary artery, right atrium, right ventricle, and superior vena cava. No significant difference was found regarding dilated cardiomyopathy, diabetes mellitus, hypertension, atrial fibrillation, and left heart valvular disease, but a significant difference was found for coronary heart disease (higher morbidity in group with PAWP ≤15 mm Hg) between the two groups.

CONCLUSION

We found that 15.6% of the patients with PH-LHD under pharmacological or nonpharmacological treatment had PAWP ≤15 mm Hg. These results suggest that the diagnostic criterion of PAWP and the characteristics for this group of patients should be further investigated.

Pulmonary Hypertension Due to Left Heart Disease

Pulmonary hypertension (PH) due to left heart disease (LHD) is the most common type of PH and is defined as mean pulmonary artery systolic pressure of >20 mm Hg and pulmonary capillary wedge pressure >15 mm Hg during right heart catheterization. LHD may lead to elevated left atrial pressure alone, which in the absence of intrinsic pulmonary vascular disease will result in PH without changes in pulmonary vascular resistance. Persistent elevation in left atrial pressure may, however, also be associated with subsequent pulmonary vascular remodeling, vasoconstriction, and an increase in pulmonary vascular resistance. Hence, there are 2 subgroups of PH due to LHD, isolated postcapillary PH and combined post- and precapillary PH, with these groups have differing clinical implications. Differentiation of pulmonary arterial hypertension and PH due to LHD is critical to guide management planning; however, this may be challenging. Older patients, patients with metabolic syndrome, and patients with imaging and clinical features consistent with left ventricular dysfunction are suggestive of LHD etiology rather than pulmonary arterial hypertension. Hemodynamic measures such as diastolic pressure gradient, transpulmonary gradient, and pulmonary vascular resistance may assist to differentiate pre- from postcapillary PH and offer prognostic insights. However, these are influenced by fluid status and heart failure treatment. Pulmonary arterial hypertension therapies have been trialed in the treatment with concerning results reflecting disease heterogeneity, variation in inclusion criteria, and mixed end point criteria. The aim of this review is to provide an updated definition, discuss possible pathophysiology, clinical aspects, and the available treatment options for PH due to LHD.

Relationship of soluble ST2 to pulmonary hypertension severity in patients undergoing cardiac resynchronization therapy

Background

Pulmonary hypertension (PH) is an adverse prognostic marker in patients undergoing cardiac resynchronization therapy (CRT). We sought to determine the relation of biomarkers of fibrosis [soluble ST2 (sST2), galectin-3], wall stretch [amino terminal pro-brain natriuretic peptide (NT-proBNP)], and necrosis [high-sensitivity troponin-I (hsTnI)] to PH severity in CRT patients.

Methods

Biomarkers and right ventricular systolic pressure (RVSP) were measured at CRT implant and 6-month later (n=111). PH was categorized into 3 groups based on RVSP: no (<35 mmHg), mild-moderate (35-60 mmHg), and severe (>60 mmHg). Patients were categorized as progressors (worsened PH), persistent PH (no change) and regressors (improved PH). Endpoints were 6-month CRT response and 2-year major adverse cardiac event (MACE).

Results

RVSP was associated with CRT nonresponse (P=0.02) and MACE (P=0.03). Severe PH patients had 5-fold increase risk for CRT nonresponse (OR 5.0, P=0.04) and MACE (HR 5.7, P=0.04) over non-PH patients. Progressors and persistent PH patients had >2-fold odds for CRT non-response (OR 2.8, P=0.45) and >11-fold increase in MACE compared to no PH patients or regressors (HR 11.6, P=0.02). Only NT-proBNP and sST2 were discernable between PH groups, with graded increase based on PH severity (both P≤0.02), and lower values in regressors versus non-regressors (both P≤0.01). Levels of sST2 decreased at 6 months in regressors (15 ng/mL, P=0.03) and increased slightly (3-8 ng/mL) in non-regressors, without difference for NT-proBNP (P=0.08).

Conclusions

sST2 levels are related with PH severity in CRT patients. Serial sST2 changes after CRT implant suggests potential role to monitor PH after CRT.

Pulmonary Hypertension and Heart Failure: A Dangerous Liaison

Pulmonary hypertension (PH) is a common hemodynamic evolution of heart failure (HF) with preserved or reduced ejection fraction, responsible for congestion, symptoms worsening, exercise limitation, and negative outcome. In HF of any origin, PH develops in response to a passive backward pressure transmission as result of increased left atrial pressure. Sustained pressure injury and chronic venous congestion can trigger pulmonary vasoconstriction and vascular remodeling, leading to irreversible pulmonary vascular disease, right ventricular hypertrophy, and failure. In this article, the key determinants of this "dangerous liaison" are analyzed with some digressions on related "leitmotiv" at the horizon.

Effect of cardiac resynchronization therapy on pulmonary function in patients with heart failure

Pulmonary congestion due to heart failure causes abnormal lung function. Cardiac resynchronization therapy (CRT) is a proven effective treatment for heart failure. The aim of this study was to test the hypothesis that CRT promotes increased lung volumes, bronchial conductance, and gas diffusion. Forty-four consecutive patients with heart failure were prospectively investigated before and after CRT. Spirometry, gas diffusion (diffusing capacity for carbon monoxide), cardiopulmonary exercise testing, New York Heart Association class, brain natriuretic peptide, the left ventricular ejection fraction, left atrial volume, and right ventricular systolic pressure were assessed before and 4 to 6 months after CRT. Pre- and post-CRT measures were compared using either paired Student's t tests or Wilcoxon's matched-pair test; p values <0.05 were considered significant. Improved New York Heart Association class, left ventricular ejection fraction, left atrial volume, right ventricular systolic pressure, and brain natriuretic peptide were observed after CRT (p <0.05 for all). Spirometry after CRT demonstrated increased percentage predicted total lung capacity (90 ± 17% vs 96 ± 15%, p <0.01) and percentage predicted forced vital capacity (80 ± 19% vs 90 ± 19%, p <0.01). Increased percentage predicted total lung capacity was significantly correlated with increased peak exercise end-tidal carbon dioxide (r = 0.43, p = 0.05). Increased percentage predicted forced vital capacity was significantly correlated with decreased right ventricular systolic pressure (r = -0.30, p = 0.05), body mass index (r = -0.35, p = 0.02) and creatinine (r = -0.49, p = 0.02), consistent with an association of improved bronchial conductance and decreased congestion. Diffusing capacity for carbon monoxide did not significantly change. In conclusion, increased lung volumes and bronchial conductance due to decreased pulmonary congestion and increased intrathoracic space contribute to an improved breathing pattern and decreased hyperventilation after CRT. Persistent alveolar-capillary membrane remodeling may account for unchanged diffusing capacity for carbon monoxide.

Treatment for pulmonary hypertension of left heart disease

OPINION STATEMENT

Pulmonary hypertension (PH) secondary to left heart disease is a largely underestimated target of therapy. Except for a specific focus on PH consequences in patients with advanced heart failure (HF) receiving a left ventricular mechanical assist device or candidates for transplantation, prevention and treatment of initial subclinical forms of PH are not considered a priority in the management of this chronic disease population. Nonetheless, there is recent growing evidence supporting a clinical and prognostic role of PH in the elderly and in HF with preserved ejection fraction (pEF). Studies have defined PH-HFpEF as a new entity typically defining the evolving nature of disease. Although the prevalence of PH in these populations is not well-defined, the potential for effective pharmacological approaches that might impact the natural history of the disease starting from earlier stages is promising. However, it should be recognized that pharmacological studies performed to date with traditional pulmonary vasodilators in cohorts with HF and left-sided PH have not been positive, primarily because of concomitant systemic hypotension and hepatic side effects. This evidence along with the lack of studies specifically performed in the elderly and HFpEF often lead Guidelines to give neutral recommendations or even arbitrary assumptions. Recent availability of selective well-tolerated pulmonary vasodilators, such as phosphodiesterase type 5 (PDE5) inhibitors, however, seem to offer a solid background for treating left-sided PH at both early and later stages of the disease process.

Pulmonary hypertension and right ventricular failure in left ventricular systolic dysfunction

PURPOSE OF REVIEW

Pulmonary hypertension and right ventricular failure (RVF) in left ventricular systolic dysfunction (LVSD) is associated with high morbidity and mortality. This review presents an overview of the classification, pathophysiology, natural history, clinical features, prevention and treatment of this common clinical problem with a focus on the most recent studies. Many of the current evidence-based therapeutic agents for pulmonary hypertension in the absence of systolic or diastolic heart failure (e.g. prostaglandins, endothelin antagonists) are not efficacious in pulmonary hypertension with LVSD.

RECENT FINDINGS

Recent clinical evidence strongly supports an evolving role for phosphodiesterase type 5 (PDE5) inhibition in patients with pulmonary hypertension and LVSD. Chronic PDE5 inhibition in the short-to-intermediate duration studies to date significantly reduces pulmonary pressures and pulmonary vascular resistance (PVR), effects reverse right ventricle and left ventricle remodeling, improves ventilator efficiency, improves peak exercise capacity and improves quality of life in selected patients with stable, moderately symptomatic LVSD and pulmonary hypertension.

SUMMARY

Although long-term outcome studies are currently lacking, chronic PDE5 inhibition should be considered in carefully selected LVSD patients who manifest persistent significant elevation of pulmonary hypertension or PVR or uncontrolled RVF after aggressive management with all standard current evidence-based LVSD therapies (neurohormonal antagonists, diuretics and cardiac resynchronization in appropriate candidates).

Pulmonary hypertension associated with left heart disease: characteristics, emerging concepts, and treatment strategies

Left heart disease (LHD) represents the most common causes of pulmonary hypertension (PH). Whether caused by systolic or diastolic dysfunction or valvular heart disease, a hallmark of PH associated with LHD is elevated left atrial pressure. In all cases, the increase in left atrial pressure causes a passive increase in pulmonary pressure. In some patients, a superimposed active component caused by pulmonary arterial vasoconstriction and vascular remodeling may lead to a further increase in pulmonary arterial pressure. When present, PH is associated with a worse prognosis in patients with LHD. In addition to local abnormalities in nitric oxide and endothelin production, gene modifiers such as serotonin polymorphisms may be associated with the pathogenesis of PH in LHD. Optimizing heart failure regimens and corrective valve surgery represent the cornerstone of the treatment of PH in LHD. Recent studies suggest that sildenafil, a phosphodiesterase-5 inhibitor, is a promising agent in the treatment of PH in LHD. Unloading the left ventricle with circulatory support may also reverse severe PH in patients with end-stage heart failure allowing candidacy to heart transplantation.

Pulmonary hypertension with left-sided heart disease

Pulmonary hypertension (PH) with left-sided heart disease is defined, according to the latest Venice classification, as a Group 2 PH, which includes left-sided ventricular or atrial disease, and left-sided valvular diseases. These conditions are all associated with increased left ventricular filling pressure. Although PH with left-sided heart disease is a common entity, and long-term follow-up trials have provided firm recognition that development of left-sided PH carries a poor outcome, available data on incidence, pathophysiology, and therapy are sparse. Mitral stenosis was reported as the most frequent cause of PH several decades ago, but PH with left-sided heart disease is now usually caused by systemic hypertension and ischemic heart disease. In patients with these conditions, PH develops as a consequence of impaired left ventricular relaxation and distensibility. Chronic sustained elevation of cardiogenic blood pressure in pulmonary capillaries leads to a cascade of untoward retrograde anatomical and functional effects that represent specific targets for therapeutic intervention. The pathophysiological and clinical importance of the hemodynamic consequences of left-sided heart disease, starting with lung capillary injury and leading to right ventricular overload and failure, are discussed in this Review, focusing on PH as an evolving contributor to heart failure that may be amenable to novel interventions.

The right heart and pulmonary circulation (III). The pulmonary circulation in heart failure

Pulmonary hypertension due to left heart disease is a pathophysiological and hemodynamic state which is present in a wide range of clinical conditions that affect left heart structures. Although the pulmonary circulation has traditionally received little attention, it is reasonable to say that today it is a fundamental part of cardiological evaluation. In patients with heart failure, the most important clinical factors are the presence of pulmonary hypertension and right ventricular function. These factors are also essential for determining prognosis and must be taken into account when making some of the most important therapeutic decisions. The pathophysiological process starts passively but later transforms into a reactive process. This latter process, in turn, has one component that can be reversed with vasodilators and another component that is fixed, in which the underlying mechanism is congestive vasculopathy (i.e. essentially medial hypertrophy and pulmonary arterial intimal fibrosis). Currently no specific therapy is available for this type of pulmonary hypertension and treatment is the same as for heart failure itself. The drugs that have been shown to be effective in pulmonary arterial hypertension have generally had a neutral effect in clinical trials. Nevertheless, we are involved in the clinical development of a number of groups of pharmacological compounds that will enable us to make progress in the near future.

Pulmonary hypertension in heart failure

BACKGROUND

Pulmonary hypertension occurs in 60% to 80% of patients with heart failure and is associated with high morbidity and mortality.

METHODS AND RESULTS

Pulmonary artery pressure correlates with increased left ventricular end-diastolic pressure. Therefore, pulmonary hypertension is a common feature of heart failure with preserved as well as reduced systolic function. Pulmonary hypertension is partially reversible with normalization of cardiac filling pressures. Pulmonary vasculature remodeling and vasoconstriction create a second component, which does not reverse immediately, but has been shown to improve with vasoactive drugs and especially with left ventricular assist devices.

CONCLUSION

Many drugs used for idiopathic pulmonary arterial hypertension are being considered as treatment options for heart failure-related pulmonary hypertension. This is of particular significance in the heart transplant population. Randomized clinical trials with interventions targeting heart failure patients with elevated pulmonary artery pressure would be justified.

PDE5A inhibitor treatment of persistent pulmonary hypertension after mechanical circulatory support

BACKGROUND

Pulmonary hypertension (PH) secondary to left heart failure portends a poor prognosis and is a relative contraindication to heart transplantation at many centers. We tested the hypothesis that when PH persists after adequate left ventricle unloading via recent left ventricular assist device (LVAD) therapy, phosphodiesterase type 5A inhibition would decrease PH in this population.

METHODS AND RESULTS

We performed an open-label clinical trial using control patients not receiving therapy. Between 1999 and 2007, 138 consecutive patients undergoing cardiac transplantation evaluation with advanced left ventricular dysfunction, an elevated pulmonary capillary wedge pressure, and PH (defined by a pulmonary vascular resistance (PVR) >3 Woods Units), were treated with LVAD therapy. Fifty-eight of these patients reduced their pulmonary capillary wedge pressure to a value <15 mm Hg (11.8+/-2.0 mm Hg from baseline 23.2+/-6.2 mm Hg) 1 to 2 weeks after LVAD implantation, but despite this improvement, the PVR of these patients was only minimally affected (5.65+/-3.00 to 5.39+/-1.78 Wood Units). Twenty-six consecutive patients from this group with persistently elevated PVR were started on oral phosphodiesterase type 5A inhibition with sildenafil and titrated to an average of dose of 51.9 mg by mouth 3 times per day. The average PVR in the sildenafil-treated group fell from 5.87+/-1.93 to 2.96+/-0.92 Wood Units (P<0.001) and the mean pulmonary artery pressure fell from 36.5+/-8.6 to 24.3+/-3.6 mm Hg (P<0.0001) and was significantly lower when compared with the 32 LVAD recipients not receiving sildenafil at weeks 12 to 15 after the initial post-LVAD hemodynamic measurements (13 to 17 weeks post-LVAD implantation). In addition, hemodynamic measurements of right ventricular function in sildenafil-treated patients was also improved compared with patients not receiving sildenafil.

CONCLUSIONS

In patients with persistent PH after recent LVAD placement, phosphodiesterase type 5A inhibition in this open-label trial resulted in a significant decrease in PVR when compared with control patients.

Pulmonary hypertension secondary to left ventricular systolic dysfunction: contemporary diagnosis and management

Pulmonary hypertension secondary to left ventricular systolic dysfunction is often a poor prognostic marker in chronic heart failure. In this article, we review evidence supporting modern strategies addressing pulmonary hypertension in patients with left ventricular systolic dysfunction, including right-sided heart catheterization with vasoreactivity testing and subsequent parenteral, oral, and inhaled therapy. We delineate a diagnostic approach to secondary pulmonary hypertension and outline evidence-based therapeutic strategies for management in acute and chronic heart failure.

Cardiac resynchronization therapy: from creation to evolution--an evidence-based review

In the past decade, cardiac resynchronization therapy (CRT), achieved by simultaneous left and right ventricular pacing, has emerged as a potent therapeutic option for patients with congestive heart failure. Electrical dyssynchrony, most often manifested by left bundle branch block on the surface 12-lead electrocardiogram, results in mechanical dyssynchrony of the left ventricular septum and free wall, which decreases cardiac efficiency. In patients with ejection fractions <30%, New York Heart Association (NYHA) class III or IV, and QRS width >120 ms, CRT improves clinical parameters such as 6-minute walk distances, quality-of-life scores, and NYHA functional class. Long-term reverse remodeling of the failing ventricle results in reductions in congestive heart failure hospitalizations and mortality independent of defibrillator therapy. While most patients show significant improvement, a small proportion fail to respond. Appropriately identifying patients who will benefit most from CRT and timing the initiation of resynchronization therapy remain areas of intense investigation.

Relation of right ventricular peak systolic pressure to major adverse events in patients undergoing cardiac resynchronization therapy

The degree to which increased right-sided heart pressures influence outcome in cardiac resynchronization therapy (CRT) is unclear. High right ventricular (RV) pressures may contribute to septal malpositioning, thus hindering effective resynchronization. We hypothesized that patients with high RV systolic pressures before CRT implantation would have poorer outcome. We evaluated echocardiograms, electrocardiograms, and clinical records from 75 consecutive patients with CRT. RV systolic pressure was calculated from the peak tricuspid regurgitant, time-velocity profile. The primary end point was a composite of mortality, cardiac transplantation, or need for a left ventricular assist device. Events were evaluated by Kaplan-Meier curves and Cox proportional hazard ratios. Patients grouped by RV systolic pressure divided at the median of 35 mm Hg were similar except for more renal insufficiency and RV dysfunction when RV systolic pressure was >35 mm Hg. Univariate analysis identified RV systolic pressure >35 mm Hg (hazard ratio [HR] 3.32), diabetes (HR 2.45), renal insufficiency (HR 3.52), atrial fibrillation (HR 3.07), use of nonamiodarone antiarrhythmic medications (HR 2.86), atrial pacing (HR 2.57), and prolonged PR interval (HR 1.009) as associated with poorer outcome. Normal sinus rhythm at implantation (HR 0.34), baseline left bundle branch block (HR 0.44), and beta-blocker use (HR 0.47) were associated with improved outcome. In a multivariable model, high RV systolic pressure (HR 3.71, 95% confidence interval 1.31 to 10.4), renal insufficiency (HR 3.18, 95% confidence interval 1.29 to 7.86), and atrial fibrillation (HR 4.22, 95% confidence interval 1.54 to 11.6) remained significant. In conclusion, despite resynchronization, patients with high RV pressures have significantly decreased survival after adjusting for significant contributing influences.

Recipient selection and management

Cardiac transplantation remains the definitive surgical solution for Stage D heart failure. However, the lack of availability of donor organs makes patient selection crucial to appropriate resource utilization. All feasible medical and surgical alternatives should be explored before consideration of transplantation is undertaken. A cardiac transplantation evaluation should be thorough to exclude patients with preexisting serious comorbidities, with particular attention being paid to renal dysfunction, pulmonary hypertension, and panel reactive antibody levels. Once accepted for listing as a cardiac transplantation recipient, patients are assigned a priority status based on the severity of illness. Organs are allocated on the basis on status level, blood type, body size, and length of time at a given status level.