Severe pulmonary hypertension in patients with severe aortic valve stenosis: clinical profile and prognostic implications

Effect of tricuspid regurgitation and the right heart on survival after transcatheter aortic valve replacement: insights from the Placement of Aortic Transcatheter Valves II inoperable cohort

BACKGROUND

Tricuspid regurgitation (TR) and right ventricular (RV) dysfunction adversely affect outcomes in patients with heart failure or mitral valve disease, but their impact on outcomes in patients with aortic stenosis treated with transcatheter aortic valve replacement has not been well characterized.

METHODS AND RESULTS

Among 542 patients with symptomatic aortic stenosis treated in the Placement of Aortic Transcatheter Valves (PARTNER) II trial (inoperable cohort) with a Sapien or Sapien XT valve via a transfemoral approach, baseline TR severity, right atrial and RV size and RV function were evaluated by echocardiography according to established guidelines. One-year mortality was 16.9%, 17.2%, 32.6%, and 61.1% for patients with no/trace (n=167), mild (n=205), moderate (n=117), and severe (n=18) TR, respectively (P<0.001). Increasing severity of RV dysfunction as well as right atrial and RV enlargement were also associated with increased mortality (P<0.001). After multivariable adjustment, severe TR (hazard ratio, 3.20; 95% confidence interval, 1.50-6.82; P=0.003) and moderate TR (hazard ratio, 1.60; 95% confidence interval, 1.02-2.52; P=0.042) remained associated with increased mortality as did right atrial and RV enlargement, but not RV dysfunction. There was an interaction between TR and mitral regurgitation severity (P=0.04); the increased hazard of death associated with moderate/severe TR only occurred in those with no/trace/mild mitral regurgitation.

CONCLUSIONS

In inoperable patients treated with transcatheter aortic valve replacement, moderate or severe TR and right heart enlargement are independently associated with increased 1-year mortality; however, the association between moderate or severe TR and an increased hazard of death was only found in those with minimal mitral regurgitation at baseline. These findings may improve our assessment of anticipated benefit from transcatheter aortic valve replacement and support the need for future studies on TR and the right heart, including whether concomitant treatment of TR in operable but high-risk patients with aortic stenosis is warranted.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01314313.

Optimizing clinical outcomes of transcatheter aortic valve implantation patients with comorbidities

Transcatheter aortic valve implantation (TAVI) has revolutionized the management of high-risk or inoperable patients presenting with symptomatic severe aortic stenosis (AS). There are several factors to consider to optimize patient outcomes from TAVI. Before TAVI, patient selection is key and an understanding the effects of common comorbidities on outcomes after TAVI is critical. Some comorbidities share common risk factors with AS (e.g. coronary artery disease), others are directly or indirectly caused or exacerbated by severe AS (e.g. atrial fibrillation, pulmonary hypertension, mitral regurgitation, tricuspid regurgitation and right ventricular dysfunction), whereas others are not directly related to severe AS (e.g. chronic kidney disease and chronic lung disease). Choice of transcatheter heart valve prosthesis, vascular access route and mode of anesthesia are important considerations during TAVI. New onset conduction disturbances and arrhythmias remain a vexing issue after TAVI. The aim of the present review is to provide an overview of these issues.

Pulmonary hypertension is a manifestation of congestive heart failure and left ventricular diastolic dysfunction in octogenarians with severe aortic stenosis

Previous studies have suggested that pulmonary hypertension (PH) in severe aortic stenosis (AS) is a risk factor for operative mortality with aortic valve replacement (AVR). Conversely, others have shown that patients with AS and PH extract a large symptomatic and survival benefit from AVR compared with those patients not treated surgically. We sought to evaluate the prevalence, severity, and mechanism of PH in an elderly patient cohort with severe AS. We prospectively evaluated 41 patients aged ≥80 years with severe AS. All patients underwent cardiac catheterization and transthoracic echocardiography within 24 hours. We found that PH was common in this cohort: 32 patients (78%) had PH; however, the predominant mechanism of PH was left heart congestion. Patients with PH had nearly double the pulmonary artery wedge pressure of patients without PH (23 vs. 13 mmHg; P ≤ 0.001). In patients with PH compared with those without, pulmonary vascular resistance was higher yet still under 3 Wood units (WU; 2.9 vs. 1.5 WU; P = 0.001), and the transpulmonary gradient (11 vs. 7 mmHg; P = 0.01) and diastolic pulmonary gradient (DPG; 3.0 vs. 2.7 mmHg; P = 0.74) were in normal range. Left ventricular diastolic abnormalities were more common in patients with severe AS and PH. Right ventricular (RV) dysfunction was common (13/41 patients, 32%), but the PH and non-PH groups had similar tricuspid annular plane systolic excursion (2.0 vs. 2.3 cm; P = 0.15). Only 2 subjects had both RV dysfunction and an elevated DPG. In conclusion, PH is common in elderly patients with severe AS. This occurs largely due to left heart congestion, with a relative absence of pulmonary vascular disease and RV dysfunction, and as such, PH may serve as a heart failure equivalent in these patients.

Prognostic Impact of Tricuspid Regurgitation in Patients Undergoing Aortic Valve Surgery for Aortic Stenosis

BACKGROUND

The prognostic significance of tricuspid regurgitation (TR) and right ventricular (RV) function in patients undergoing aortic valve replacement (AVR) for severe aortic stenosis (AS) is unknown. The aim of the present study was to evaluate the impact of TR and RV systolic dysfunction on early and late mortality in this setting.

METHODS

This was a prospective single-center observational study. 465 consecutive patients who were referred to AVR for severe AS were investigated. Significant TR was defined as TR≥moderate by transthoracic echocardiography.

RESULTS

At baseline, significant TR was present in 26 (5.6%) patients. Patients with TR presented with a higher EuroSCORE I (p = 0.001), a higher incidence of previous cardiac surgery (p<0.001), pulmonary hypertension (p = 0.003), more dilated RVs (p = 0.001), and more frequent RV dysfunction (p = 0.001). Patients were followed for an average of 5.2 (±2.8 SD) years. By multivariable Cox regression analysis TR (p = 0.014), RV dysfunction (p = 0.046), age (p = 0.001) and concomitant coronary artery bypass graft surgery (CABG, p = 0.003) were independently associated with overall mortality. By Kaplan-Meier analysis, survival rates were significantly worse in patients with significant than with non-significant TR (log rank p = 0.001).

CONCLUSIONS

TR, RV dysfunction, age, and concomitant CABG are associated with outcome in patients undergoing AVR for severe AS. This finding underlines the importance of a thorough echocardiographic evaluation with particular consideration of the right heart in these patients.

Risk stratification in patients with pulmonary hypertension undergoing transcatheter aortic valve replacement

OBJECTIVE

Pulmonary hypertension (PH) is associated with increased mortality after surgical or transcatheter aortic valve replacement (TAVR) for aortic stenosis (AS), and when the pulmonary artery pressure is particularly elevated, there may be questions about the clinical benefit of TAVR. We aimed to identify clinical and haemodynamic factors associated with increased mortality after TAVR among those with moderate/severe PH.

METHODS

Among patients with symptomatic AS at high or prohibitive surgical risk receiving TAVR in the Placement of Aortic Transcatheter Valves (PARTNER) I randomised trial or registry, 2180 patients with an invasive measurement of mean pulmonary artery pressure (mPAP) recorded were included, and moderate/severe PH was defined as an mPAP ≥35 mm Hg.

RESULTS

Increasing severity of PH was associated with progressively worse 1-year all-cause mortality: none (n=785, 18.6%), mild (n=838, 22.7%) and moderate/severe (n=557, 25.0%) (p=0.01). The increased hazard of mortality associated with moderate/severe PH was observed in females, but not males (interaction p=0.03). In adjusted analyses, females with moderate/severe PH had an increased hazard of death at 1 year compared with females without PH (adjusted HR 2.14, 95% CI 1.44 to 3.18), whereas those with mild PH did not. Among males, there was no increased hazard of death associated with any severity of PH. In a multivariable Cox model of patients with moderate/severe PH, oxygen-dependent lung disease, inability to perform a 6 min walk, impaired renal function and lower aortic valve mean gradient were independently associated with increased 1-year mortality (p<0.05 for all), whereas several haemodynamic indices were not. A risk score, including these factors, was able to identify patients with a 15% vs 59% 1-year mortality.

CONCLUSIONS

The relationship between moderate/severe PH and increased mortality after TAVR is altered by sex, and clinical factors appear to be more influential in stratifying risk than haemodynamic indices. These findings may have implications for the evaluation of and treatment decisions for patients referred for TAVR with significant PH.

TRIAL REGISTRATION

NCT00530894.

Effect of preoperative oral sildenafil on severe pulmonary artery hypertension in patients undergoing mitral valve replacement

Aim:

Long standing mitral valve disease is usually associated with severe pulmonary hypertension. Perioperative pulmonary hypertension is a risk factor for right ventricular (RV) failure and a cause for morbidity and mortality in patients undergoing mitral valve replacement. Phosphodiesterase 5 inhibitor-sildenafil citrate is widely used to treat primary pulmonary hypertension. There is a lack of evidence of effects of oral sildenafil on secondary pulmonary hypertension due to mitral valve disease. The study aims to assess the effectiveness of preoperative oral sildenafil on severe pulmonary hypertension and incidence of RV failure in patients undergoing mitral valve replacement surgery.

Materials and Methods:

A total of 40 patients scheduled for mitral valve replacement with severe pulmonary hypertension (RV systolic pressure (RVSP) ≥60 mmHg) on preoperative transthoracic echo were randomly treated with oral sildenafil 25 mg (N = 20) or placebo (N = 20) eight hourly for 24 h before surgery. Hemodynamic variables were measured 20 min after insertion of pulmonary artery catheter (PAC) under anesthesia (T1), 20 min at weaning from cardiopulmonary bypass (CPB) (T2) and after 1,2, and 6 h (T3, T4, T5, respectively) during the postoperative period.

Results:

Systolic and mean pulmonary artery pressure (MPAP) and pulmonary vascular resistance index (PVRI) were significantly lower (P < 0.0001) in sildenafil group at all times. Ventilation time and postoperative recovery room stay were significantly lower (P < 0.001) in sildenafil group.

Conclusion:

Sildenafil produces significant pulmonary vasodilatory effect as compared with placebo in mitral valve replacement patients with severe pulmonary hypertension. It also reduces ventilation time and intensive care unit (ICU) stay time as compared with placebo. It is concluded that sildenafil is effective in reducing pulmonary hypertension when administered preoperatively in patients with severe pulmonary hypertension undergoing mitral valve replacement surgery.

Long-term outcome after transcatheter aortic valve implantation

OBJECTIVE

To assess late outcome after transcatheter aortic valve implantation (TAVI) up to 6 years and to analyse its predictive factors with a particular emphasis on functional status. Very few data exist on the long-term results of TAVI, and these data are crucial for decision making.

METHODS

Between October 2006 and December 2009, 123 consecutive patients were discharged alive after TAVI in our institution. Mean age was 82±8 years, and 88% of patients were highly symptomatic in New York Heart Association (NYHA) class III-IV.

RESULTS

Follow-up was complete in 122 patients (99%). The overall 6-year survival rate was 31%±5%, the majority of deaths being non-cardiac. Predictive factors of late mortality were the presence of lower limb arteritis (p=0.009), a higher Charlson comorbidity index (p=0.03) and post-TAVI paraprosthetic aortic regurgitation ≥2/4 (p=0.01). Late outcomes according to Valve Academic Research Consortium-2 criteria were analysed, and the 5-year event-free survival rate was 28%±4%. Finally, the rate of good functional results, defined as survival in NYHA class I or II, was 32%±5% at 5-year follow-up. In the survivors, the EQ-5D questionnaire further confirmed the benefit in terms of quality of life.

CONCLUSIONS

About one-third of patients discharged alive after TAVI were alive at 6-year follow-up, and the survivors exhibited good functional results assessed by NYHA class and quality-of-life standardised evaluation.

Prognostic impact of pulmonary artery systolic pressure in patients undergoing transcatheter aortic valve replacement for aortic stenosis

Baseline pulmonary hypertension (PH) is a predictor of poor outcomes in patients with severe aortic stenosis (AS). Surgical aortic valve replacement is thought to alleviate PH. The aim of this study was to determine the prognostic impact of PH in patients who underwent transcatheter aortic valve replacement (TAVR). An observational cohort study was conducted using prospectively collected data on 277 consecutive patients with severe AS who underwent TAVR at the Mayo Clinic (Rochester, Minnesota) from November 1, 2008, to June 31, 2013. Clinical and echocardiographic data, pulmonary function characteristics, and outcomes stratified by tertiles of pulmonary artery systolic pressure (PASP) were analyzed. From 277 patients who underwent TAVR, 251 patients had PASP assessment at baseline. Those in the highest PASP tertile (PASP ≥49 mm Hg) had more severe chronic lung disease and worse diastolic dysfunction. Being in the highest PASP tertile was an independent predictor of long-term mortality (hazard ratio 2.88, 95% confidence interval 1.15 to 7.23). Patients in the highest PASP tertile had longer lengths of hospital stay, while other short-term outcomes (30-day mortality and readmission, stroke, prolonged ventilation, and reoperation for bleeding) were similar across PASP tertiles. TAVR was associated with a decrease in PASP in the highest PASP tertile at 1 week after the procedure (-8 ± 14 mm Hg) and at 3 months (-7 ± 15 mm Hg) compared with baseline. In conclusion, among patients with severe AS who underwent TAVR, higher baseline PASP was strongly associated with diastolic dysfunction and chronic lung disease. Patients with higher baseline PASP tolerated TAVR relatively well in the early postprocedural phase, with diminished long-term survival. PH should not disqualify patients with severe AS from consideration for TAVR.

Severe aortic stenosis: forgotten associations

The authors present the case of a 68-year-old man with predominantly right heart failure in the context of severe aortic stenosis associated with pulmonary hypertension. Anemia was diagnosed which, after endoscopic study, was considered to be secondary to angiodysplasia and a diagnosis of Heyde syndrome was made. After valve replacement surgery the patient's heart failure improved and hemoglobin levels stabilized. We present this case to show the need to recognize less common associations of severe aortic stenosis, in order to provide immediate and appropriate treatment.

Survival by stroke volume index in patients with low-gradient normal EF severe aortic stenosis

OBJECTIVE

Low-gradient (LG) severe aortic stenosis (AS) and preserved EF with reduced stroke volume are associated with an adverse prognosis, but the relationship of stroke volume index (SVI) with mortality among a range of values is unknown. We investigated the prognostic impact of SVI in this population.

METHODS

We examined 405 consecutive patients with preserved EF (≥50%) and severe AS (valve area <1.0 cm(2)) with LG (<40 mm Hg) using echocardiography. Patients were stratified into quartiles based on SVI distribution (group 1: <38 mL/m(2) (n=90), group 2: 38-43 mL/m(2) (n=105), group 3: 43-48 mL/m(2) (n=104) and group 4: >48 mL/m(2) (n=106)).

RESULTS

Groups 1 and 2 had poorer survival with medical management compared with 3 and 4 (3-year estimate 46% and 67% vs. 78% and 73%, respectively, p=0.002) although aortic valve replacement referral rate was similar (53%-62%, p=0.57). An inverse relationship was observed between SVI and mortality (HR 1.28 (1.11 to 1.46) per every 5 mL/m(2) decrease in SVI). After multivariable analysis, SVI was the strongest predictor of mortality (HR 0.92 (0.89 to 0.95), p<0.0001). Using different SVI cutpoints, SVI <35 was associated with highest mortality (HR 2.36 (1.49 to 3.73), p<0.001), followed by SVI <38 (HR 2.09 (1.39 to 3.16), p<0.001) and by SVI <43 (HR 2.05 (1.38 to 3.05), p<0.001). Survival with SVI ≥43 was similar to age and sex-matched controls (3-year estimate 84%, p=0.24); survival for SVI <43 was significantly worse (3-year estimate 63%, p<0.001).

CONCLUSIONS

Lower SVI is incrementally associated with mortality in LG severe AS with preserved EF. These findings have implications for classification of AS severity, identification of high-risk groups and subsequent management.

Role of echocardiography in aortic stenosis

Aortic stenosis is a valve disorder that includes not only valve narrowing but also changes in the left ventricle and intracardiac hemodynamics. Older patients with aortic stenosis often have co-existing pathologic disorders, which influence the pathophysiology, symptom expression and prognosis. There is also increasing awareness that severe aortic stenosis could be associated with low transvalvular pressure gradient caused by a variety of mechanisms. Surgical and transcutaneous valve replacements are currently available interventions for patients with severe aortic stenosis. This article reviews the role of echocardiography in the comprehensive assessment of aortic stenosis, its severity and associated pathophysiologic abnormalities.

Saudi Guidelines on the Diagnosis and Treatment of Pulmonary Hypertension: Perioperative management in patients with pulmonary hypertension

Patients with pulmonary hypertension (PH) are being encountered more commonly in the perioperative period and this trend is likely to increase as improvements in the recognition, management, and treatment of the disease continue to occur. Management of these patients is challenging due to their tenuous hemodynamic status. Recent advances in the understanding of the patho-physiology, risk factors, monitoring, and treatment of the disease provide an opportunity to reduce the morbidity and mortality associated with PH in the peri-operative period. Management of these patients requires a multi-disciplinary approach and meticulous care that is best provided in centers with vast experience in PH.

In this review, we provide a detailed discussion about oerioperative strategies in PH patients, and give evidence-based recommendations, when applicable.

Saudi Guidelines on the Diagnosis and Treatment of Pulmonary Hypertension: Pulmonary hypertension due to left heart disease

Pulmonary hypertension (PH) due to left heart disease is the most common cause of pulmonary hypertension in the western world. It is classified as WHO PH group II. Different pathophysiologic abnormalities may take place in this condition, including pulmonary venous congestion and vascular remodeling. Despite the high prevalence of WHO group 2 PH, the major focus of research on PH over the past decade has been on WHO group 1 pulmonary arterial hypertension (PAH). Few investigators have focused on WHO group 2 PH; consequently, the pathophysiology of this condition remains poorly understood, and no specific therapy is available. Clinical and translational studies in this area are much needed and have the potential to positively affect large numbers of patients. In this review, we provide a detailed discussion upon the pathophysiology of the disease, the recent updates in classification, and the diagnostic and therapeutic algorithms.

The novel regulations of MEF2A, CAMKK2, CALM3, and TNNI3 in ventricular hypertrophy induced by arsenic exposure in rats

Arsenic is a ubiquitous toxic compound that exists naturally in many sources such as soil, groundwater, and food; in which vast majority forms are arsenite (As(3+)) or arsenate (As(5+)). The mechanism of arsenic detoxification in humans still remains obscured. Epidemiologic studies documented that arsenic pollution caused black foot disease, cardiovascular diseases (hypertension, hypotension, cardiomyopathy), bladder cancer and skin cancer in many countries in which Taiwan is considered as high arsenic exposure country for long time ago. However, the effects of arsenic to cardiac functions still lacked of investigation while some studies mainly focus on inflammatory and cancer mechanisms. In the present study, we found cardiac hypertrophy signaling may be the most significant pathway for up regulated genes in arsenic exposed patients via bioinformatics approach. To verify our bioinformatics prediction, arsenic was fed orally to rats at different concentration based on previous studies in Taiwan. Using hemodynamic method as the main tool to measure the changes in blood pressure, left ventricular pressure and left ventricular contractility index, the findings suggest that highly exposure to arsenic lead to hypertension; elevated left ventricular diastolic pressure and alteration in cardiac contractility which are supposed to be the interaction between arsenic and cardiac nerves activity via the changing in calcium homeostasis. Collectively, based on our real-time PCR and western blot data strongly suggest that calcium homeostasis may also go through MEF2A, TNNI3, CAMKK2, CALM3 and cardiac hypertrophy relative signaling pathway.

Predictors of hospitalisations for heart failure and mortality in patients with pulmonary hypertension associated with left heart disease: a systematic review

OBJECTIVES

Left heart disease (LHD) is the main cause of pulmonary hypertension (PH), but little is known regarding the predictors of adverse outcome of PH associated with LHD (PH-LHD). We conducted a systematic review to investigate the predictors of hospitalisations for heart failure and mortality in patients with PH-LHD.

DESIGN

Systematic review.

DATA SOURCES

PubMed MEDLINE and SCOPUS from inception to August 2013 were searched, and citations identified via the ISI Web of Science.

STUDY SELECTION

Studies that reported on hospitalisation and/or mortality in patients with PH-LHD were included if the age of participants was greater than 18 years and PH was diagnosed using Doppler echocardiography and/or right heart catheterisation. Two reviewers independently selected studies, assessed their quality and extracted relevant data.

RESULTS

In all, 45 studies (38 from Europe and USA) were included among which 71.1% were of high quality. 39 studies were published between 2003 and 2013. The number of participants across studies ranged from 46 to 2385; the proportion of men from 21% to 91%; mean/median age from 63 to 82 years; and prevalence of PH from 7% to 83.3%. PH was consistently associated with increased mortality risk in all forms of LHD, except for aortic valve disease where findings were inconsistent. Six of the nine studies with data available on hospitalisations reported a significant adverse effect of PH on hospitalisation risk. Other predictors of adverse outcome were very broad and heterogeneous including right ventricular dysfunction, functional class, left ventricular function and presence of kidney disease.

CONCLUSIONS

PH is almost invariably associated with increased mortality risk in patients with LHD. However, effects on hospitalisation risk are yet to be fully characterised; while available evidence on the adverse effects of PH have been derived essentially from Caucasians.

Perioperative management of the patient with pulmonary hypertension

Patients with pulmonary hypertension are at increased risk for perioperative morbidity and mortality. Elective surgery is generally discouraged in this patient population; however, there are times when surgery is deemed necessary. Currently, there are no guidelines for the preoperative risk assessment or perioperative management of subjects with pulmonary hypertension. The majority of the literature evaluating perioperative risk factors and mortality rates is observational and includes subjects with multiple etiologies of pulmonary hypertension. Subjects with pulmonary arterial hypertension, also referred to as World Health Organization group I pulmonary hypertension, and particularly those receiving pulmonary arterial hypertension-specific therapy may be at increased risk. Perioperative management of these patients requires a solid understanding and careful consideration of the hemodynamic effects of anesthetic agents, positive pressure ventilation and volume shifts associated with surgery in order to prevent acute right ventricular failure. We reviewed the most recent data regarding perioperative morbidity and mortality for subjects with pulmonary hypertension in an effort to better guide preoperative risk assessment and perioperative management by a multidisciplinary team.

Prognostic implications of pulmonary hypertension in patients with severe aortic stenosis undergoing transcatheter aortic valve implantation: study from the FRANCE 2 Registry

BACKGROUND

Pulmonary hypertension (PH) is associated with poor prognosis in patients with severe aortic stenosis. The aim of this multicenter study was to describe clinical outcome after transcatheter aortic valve implantation.

METHODS AND RESULTS

The FRANCE 2 Registry included all patients undergoing transcatheter aortic valve implantation in France in 2010 and 2011. Patients were divided into 3 groups depending on systolic pulmonary artery pressure (sPAP) estimated in transthoracic echocardiography: group I, sPAP <40 mm Hg (no PH); group II, sPAP 40 to 59 mm Hg (mild-to-moderate PH); and group III, sPAP ≥60 mm Hg (severe PH). Patients were followed up for 1 year. A total of 2435 patients whose pre-transcatheter aortic valve implantation sPAP was reported were included. A total of 845 were in group I (34.7%), 1112 in group II (45.7%), and 478 in group III (19.6%). Procedural success, early complications, and 30-day mortality were statistically similar across sPAP groups. One-year mortality was higher in groups II and III (group I, 22%; group II, 28%; and group III, 28%; P=0.032). Mild-to-moderate and severe PH were identified as an independent factor of all-cause mortality. The major adverse cardiovascular event rates did not differ according to sPAP. New York Health Association functional class improved significantly in all groups.

CONCLUSIONS

PH (sPAP ≥40 mm Hg) in patients with aortic stenosis undergoing transcatheter aortic valve implantation was associated with increased 1-year mortality especially when severe (sPAP ≥60 mm Hg) but not with increased 30-day mortality, and functional status was significantly improved regardless of PAP level.

WHO's in second?: A practical review of World Health Organization group 2 pulmonary hypertension

World Health Organization (WHO) group 2 pulmonary hypertension (PH) due to left-side heart disease (ie, heart failure or left-sided valvular heart disease) is the most common form of PH in western countries. Distinguishing patients with WHO group 2 PH, particularly the subset of patients with PH due to heart failure with preserved ejection fraction (HFpEF), from those with WHO group 1 pulmonary arterial hypertension (PAH) is challenging. Separating the two conditions is of vital importance because treatment strategies differ completely. Furthermore, therapies that are indicated for WHO group 1 PAH may be harmful in patients with WHO group 2 PH. We review the somewhat confusing PH nomenclature and the WHO classification system and rationale behind it. We then focus on left-side heart disorders that cause PH. An aging population and advances in the medical management of common cardiovascular disorders have caused the prevalence of heart failure to rise significantly, with more than one-half of patients having HFpEF. We review contemporary studies that focus on clinical and echocardiographic findings that help to distinguish HFpEF from PAH in the patient with PH. We discuss the typical, and sometimes atypical, hemodynamic profiles that characterize these two groups, review challenges in the interpretation of data obtained by right-sided heart catheterization, and highlight special maneuvers that may be required for accurate diagnosis. Finally, we review the largely disappointing studies on the use of PAH-specific therapies in patients with WHO group 2 PH, including the use of prostacyclins, endothelin receptor antagonists, and the more promising phosphodiesterase-5 inhibitors.

Effect of preoperative pulmonary hypertension on outcomes in patients with severe aortic stenosis following surgical aortic valve replacement

Pulmonary hypertension (PH) is prevalent in patients with aortic stenosis (AS); however, previous studies have demonstrated inconsistent results regarding the association of PH with adverse outcomes after aortic valve replacement (AVR). The goal of this study was to evaluate the effects of preoperative PH on outcomes after AVR. We performed a regional prospective cohort study using the Northern New England Cardiovascular Disease Study Group database to identify 1,116 consecutive patients from 2005 to 2010 who underwent AVR ± coronary artery bypass grafting for severe AS with a preoperative assessment of pulmonary pressures by right-sided cardiac catheterization. PH was defined as a mean pulmonary artery pressure of ≥25 mm Hg, with severity based on the pulmonary artery systolic pressure-mild, 35 to 44 mm Hg; moderate, 45 to 59 mm Hg; and severe, ≥60 mm Hg. We found that PH was present in 536 patients (48%). Postoperative acute kidney injury, low-output heart failure, and in-hospital mortality increased with worsening severity of PH. In multivariate logistic regression, severe PH was independently associated with postoperative acute kidney injury (adjusted odds ratio 4.1, 95% confidence interval [CI] 1.7 to 10, p = 0.002) and in-hospital mortality (adjusted odds ratio 6.9, 95% CI 2.5 to 19.1, p <0.001). There was a significant association between PH and decreased 5-year survival (adjusted log-rank p value = 0.006), with severe PH being associated with the poorest survival (adjusted hazard ratio 2.4, 95% CI 1.3 to 4.2, p = 0.003). In conclusion, severe PH in patients with severe AS is associated with increased rates of in-hospital adverse events and decreased 5-year survival after AVR.

Management of pulmonary hypertension in left heart disease

Pulmonary hypertension (PH) due to left heart disease is classified as group II according to the Dana Point classification, which includes left ventricular systolic and/or diastolic left heart failure, and left-sided valvular disease. PH due to left heart disease is the most common cause and when present, especially with right ventricular dysfunction, is associated with a worse prognosis. Left heart disease with secondary PH is associated with increased left atrial pressure, which causes a passive increase in pulmonary pressure. Passive PH could be superimposed by an active protective, and in some patients by an ‘out of proportion’, elevated precapillary pulmonary vasoconstriction and vascular remodelling which leads to greater or lesser further increase of the pulmonary artery pressure. In this review, epidemiological and pathophysiologic mechanisms for the development of group II PH are summarized. The conflicting data about the haemodynamic and possible parameters to diagnose passive versus reactive and ‘out of proportion’ PH are presented. The different therapeutic concepts, along with novel treatment strategies, are reviewed in detail and critically discussed regarding their effectiveness and safety.

Determinants and prognostic significance of exercise pulmonary hypertension in asymptomatic severe aortic stenosis

BACKGROUND

Recent studies emphasized the usefulness of exercise stress echocardiography in asymptomatic patients with aortic stenosis. Nevertheless, the additive value of exercise pulmonary hypertension (Ex-PHT) in such patients remains unexplored. We therefore aimed to identify the determinants and to test the impact on outcome of Ex-PHT in asymptomatic patients with severe aortic stenosis.

METHOD AND RESULTS

Asymptomatic patients with severe aortic stenosis (n=105; aortic valve area <0.6 cm(2)/m(2); age, 71±9 years; male, 59%) and preserved left ventricular systolic function (ejection fraction ≥55%) were prospectively submitted to exercise stress echocardiography. Resting PHT and Ex-PHT were defined as a systolic pulmonary arterial pressure >50 and >60 mm Hg, respectively. Ex-PHT was more frequent than resting PHT (55% versus 6%; P<0.0001). On multivariable logistic regression, the independent predictors of Ex-PHT were male sex (odds ratio, 4.3; P=0.002), resting systolic pulmonary arterial pressure (odds ratio, 1.16; P=0.002), exercise indexed left ventricular end-diastolic volume (odds ratio, 1.04; P=0.026), exercise e'-wave velocity (odds ratio, 1.35; P=0.047), and exercise-induced changes in indexed left atrial area (odds ratio, 1.36; P=0.006). Ex-PHT was associated with reduced cardiac event-free survival (at 3 years, 22±7% versus 55±9%; P=0.014). In a multivariable Cox proportional hazards model, Ex-PHT was identified as an independent predictor of cardiac events (hazard ratio, 1.8; 95% confidence interval, 1.0-3.3; P=0.047). When exercise-induced changes in mean aortic pressure gradient were added to the multivariable model, Ex-PHT remained independently associated with reduced cardiac event-free survival (hazard ratio, 2.0; 95% confidence interval, 1.1-3.6; P=0.025).

CONCLUSIONS

In asymptomatic patients with severe aortic stenosis, the main determinants of Ex-PHT are male sex, resting systolic pulmonary arterial pressure, and exercise parameters of diastolic burden. Moreover, Ex-PHT is associated with a 2-fold increased risk of cardiac events. These results strongly support the use of exercise stress echocardiography in asymptomatic aortic stenosis.

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.

Impact of pulmonary hypertension on outcomes after aortic valve replacement for aortic valve stenosis

OBJECTIVE

The presence of pulmonary hypertension historically has been considered a significant risk factor affecting early and late outcomes after valve replacement. Given the number of recent advances in the management of pulmonary hypertension after cardiac surgery, a better understanding of its impact on outcomes may assist in the clinical management of these patients. The purpose of this study was to determine whether pulmonary hypertension remains a risk factor in the modern era for adverse outcomes after aortic valve replacement for aortic valve stenosis.

METHODS

From January 1996 to June 2009, a total of 1080 patients underwent aortic valve replacement for primary aortic valve stenosis, of whom 574 (53%) had normal systolic pulmonary artery pressures (sPAP) and 506 (47%) had pulmonary hypertension. Pulmonary hypertension was defined as mild (sPAP 35-44 mm Hg), moderate (45-59 mm Hg), or severe (≥ 60 mm Hg). In the group of patients with pulmonary hypertension, 204 had postoperative echocardiograms.

RESULTS

Operative mortality was significantly higher in patients with pulmonary hypertension (47/506, 9%, vs 31/574, 5%, P = .02). The incidence of postoperative stroke was similar (P = .14), but patients with pulmonary hypertension had an increased median hospital length of stay (8 vs 7 days, P = .001) and an increased incidence of prolonged ventilation (26% vs 17%, P < .001). Preoperative pulmonary hypertension was an independent risk factor for decreased long-term survival (relative risk 1.7, P = .02). Those with persistent pulmonary hypertension postoperatively had decreased survival. Five-year survival (Kaplan-Meier) was 78% ± 6% with normal sPAP and 77% ± 7% with mild pulmonary hypertension postoperatively, compared with 64% ± 8% with moderate and 45% ± 12% with severe pulmonary hypertension (P < .001).

CONCLUSIONS

In patients undergoing aortic valve replacement, preoperative pulmonary hypertension increased operative mortality and decreased long-term survival. Patients with persistent moderate or severe pulmonary hypertension after aortic valve replacement had decreased long-term survival. These data suggest that pulmonary hypertension had a significant impact on outcomes in patients undergoing aortic valve replacement and should be considered in preoperative risk assessment.

Pulmonary hypertension in cardiac surgery

Pulmonary hypertension is an important prognostic factor in cardiac surgery associated with increased morbidity and mortality. With the aging population and the associated increase severity of illness, the prevalence of pulmonary hypertension in cardiac surgical patients will increase. In this review, the definition of pulmonary hypertension, the mechanisms and its relationship to right ventricular dysfunction will be presented. Finally, pharmacological and non-pharmacological therapeutic and preventive approaches will be presented.

Pulmonary hypertension related to left-sided cardiac pathology

Pulmonary hypertension (PH) is the end result of a variety of diverse pathologic processes. The chronic elevation in pulmonary artery pressure often leads to right ventricular pressure overload and subsequent right ventricular failure. In patients with left-sided cardiac disease, PH is quite common and associated with increased morbidity and mortality. This article will review the literature as it pertains to the epidemiology, pathogenesis, and diagnosis of PH related to aortic valve disease, mitral valve disease, left ventricular systolic and diastolic dysfunction, and pulmonary veno-occlusive disease. Moreover, therapeutic strategies, which focus on treating the underlying cardiac pathology will be discussed.

Modulating the nitric oxide - cyclic GMP pathway in the pressure-overloaded left ventricle and group II pulmonary hypertension

Group II pulmonary hypertension (PH) commonly occurs in the setting of a pressure-overloaded left ventricle (LV) which is also conducive to the development of heart failure with preserved ejection fraction. Population trends and a high prevalence of underlying causative conditions, such as essential hypertension or aortic stenosis, have increased the awareness of the pressure-overloaded LV and associated group II pulmonary hypertension. Patients often exhibit poor exercise tolerance and signs of heart failure indistinguishable from systolic heart failure; but effective medical treatments in this area have been lacking. Recent preclinical work has shed light on how the down-regulated nitric oxide - cyclic GMP pathway (within the myocardium and pulmonary vasculature) contributes to the pathophysiology of these associated conditions. This article will discuss the impact of the nitric oxide - cyclic GMP pathway on the pathogenesis of the pressure-overloaded LV and group II pulmonary hypertension, and will also introduce the potential therapeutic value of modulating this pathway.

Aortic stenosis: clinical aspects of diagnosis and management, with 10 illustrative case reports from a 25-year experience

Aortic stenosis (AS) is a chronic, progressive disease predominantly affecting individuals aged over 60 years. Symptoms are the result of progressive left ventricular outflow obstruction, and herald rapid clinical decline and high mortality. Medical therapies for AS remain ineffective; operative valve replacement remains the only effective long-term treatment. We review clinical aspects of diagnosis and management of AS in adults, with attention to the natural history before and after valve replacement, assessment of suspected and established AS, and recommended management in general and in difficult clinical scenarios. We conclude with a series of 10 cases illustrating management of common, uncommon, and challenging clinical scenarios encountered at the University of Washington.

Relation of left atrial dysfunction to pulmonary artery hypertension in patients with aortic stenosis and left ventricular systolic dysfunction

Pulmonary artery hypertension (PAH) increases mortality in patients with severe aortic stenosis. We hypothesized that left atrial (LA) dysfunction would be related to PAH in patients with severe aortic stenosis complicated by left ventricular (LV) systolic dysfunction. The data from 70 patients with severe aortic stenosis and LV systolic dysfunction were analyzed. From the transmitral flow, the peak early (E) and late (A) diastolic velocities were obtained. From the pulmonary vein flow, the peak S-wave, D-wave, and reversed atrial wave velocities were determined. The right ventricular systolic pressure was measured in 50 patients and averaged 38 +/- 13 mm Hg. Patients with PAH (n = 19) presented with greater LV diameters, E/A ratio, E-wave velocity, LV mass index, reversed atrial wave velocity, and LA volume (p <0.05) and lower S/D ratio and total and active LA emptying fractions (p <0.05). Simple linear regression analysis revealed that the LA volumes and total and active LA emptying fractions displayed the strongest correlations with the right ventricular systolic pressure. Multiple regression analysis revealed that the minimum LA volume (r = 0.61, p = 0.0001) independently correlated with the right ventricular systolic pressure, irrespective of the aortic valve (AV) area or gradient. In patients who underwent an echocardiographic examination >or=1 month after AV replacement, LA function had improved significantly. The degree of improvement was related to the degree of recovery of the LV diastolic function and diameter. In conclusion, in patients with severe aortic stenosis and concomitant LV systolic dysfunction, the LA function parameters displayed the strongest correlations with the right ventricular systolic pressure, irrespective of the AV area or gradient and were impaired in patients with PAH. LA function recovered after AV replacement. Additional studies are warranted to determine the prognostic significance of LA function in this setting.