Pulmonary arterial hypertension treatment: an individual participant data network meta-analysis.

BACKGROUND AND AIMS: Effective therapies that target three main signalling pathways are approved to treat pulmonary arterial hypertension (PAH). However, there are few large patient-level studies that compare the effectiveness of these pathways. The aim of this analysis was to compare the effectiveness of the treatment pathways in PAH and to assess treatment heterogeneity. METHODS: A network meta-analysis was performed using individual participant data of 6811 PAH patients from 20 Phase III randomized clinical trials of therapy for PAH that were submitted to the US Food and Drug Administration. Individual drugs were grouped by the following treatment pathways: endothelin, nitric oxide, and prostacyclin pathways. RESULTS: The mean (±standard deviation) age of the sample was 49.2 (±15.4) years; 78.4% were female, 59.7% had idiopathic PAH, and 36.5% were on background PAH therapy. After covariate adjustment, targeting the endothelin + nitric oxide pathway {ß: 43.7 m [95% confidence interval (CI): 32.9, 54.4]}, nitric oxide pathway [ß: 29.4 m (95% CI: 22.6, 36.3)], endothelin pathway [ß: 25.3 m (95% CI: 19.8, 30.8)], and prostacyclin pathway [oral/inhaled ß: 19.1 m (95% CI: 14.2, 24.0), intravenous/subcutaneous ß: 24.4 m (95% CI: 15.1, 33.7)] significantly increased 6 min walk distance at 12 or 16 weeks compared with placebo. Treatments also significantly reduced the likelihood of having clinical worsening events. There was significant heterogeneity of treatment effects by age, body mass index, hypertension, diabetes, and coronary artery disease. CONCLUSIONS: Drugs targeting the three traditional treatment pathways significantly improve outcomes in PAH, with significant treatment heterogeneity in patients with some comorbidities. Randomized clinical trials are warranted to identify the most effective treatment strategies in a personalized approach.

Latent Pulmonary Vascular Disease May Alter the Response to Therapeutic Atrial Shunt Device in Heart Failure.

BACKGROUND: In REDUCE LAP-HF II (A Study to Evaluate the Corvia Medical, Inc IASD System II to Reduce Elevated Left Atrial Pressure in Patients With Heart Failure), implantation of an atrial shunt device did not provide overall clinical benefit for patients with heart failure with preserved or mildly reduced ejection fraction. However, prespecified analyses identified differences in response in subgroups defined by pulmonary artery systolic pressure during submaximal exercise, right atrial volume, and sex. Shunt implantation reduces left atrial pressures but increases pulmonary blood flow, which may be poorly tolerated in patients with pulmonary vascular disease (PVD). On the basis of these results, we hypothesized that patients with latent PVD, defined as elevated pulmonary vascular resistance during exercise, might be harmed by shunt implantation, and conversely that patients without PVD might benefit. METHODS: REDUCE LAP-HF II enrolled 626 patients with heart failure, ejection fraction ≥40%, exercise pulmonary capillary wedge pressure ≥25 mm Hg, and resting pulmonary vascular resistance <3.5 Wood units who were randomized 1:1 to atrial shunt device or sham control. The primary outcome-a hierarchical composite of cardiovascular death, nonfatal ischemic stroke, recurrent HF events, and change in health status-was analyzed using the win ratio. Latent PVD was defined as pulmonary vascular resistance ≥1.74 Wood units (highest tertile) at peak exercise, measured before randomization. RESULTS: Compared with patients without PVD (n=382), those with latent PVD (n=188) were older, had more atrial fibrillation and right heart dysfunction, and were more likely to have elevated left atrial pressure at rest. Shunt treatment was associated with worse outcomes in patients with PVD (win ratio, 0.60 [95% CI, 0.42, 0.86]; P=0.005) and signal of clinical benefit in patients without PVD (win ratio, 1.31 [95% CI, 1.02, 1.68]; P=0.038). Patients with larger right atrial volumes and men had worse outcomes with the device and both groups were more likely to have pacemakers, heart failure with mildly reduced ejection fraction, and increased left atrial volume. For patients without latent PVD or pacemaker (n=313; 50% of randomized patients), shunt treatment resulted in more robust signal of clinical benefit (win ratio, 1.51 [95% CI, 1.14, 2.00]; P=0.004). CONCLUSIONS: In patients with heart failure with preserved or mildly reduced ejection fraction, the presence of latent PVD uncovered by invasive hemodynamic exercise testing identifies patients who may worsen with atrial shunt therapy, whereas those without latent PVD may benefit.

Exception-Status Listing: A Critical Pathway to Heart Transplantation for Adults With Congenital Heart Diseases.

Adults with congenital heart diseases may not be candidates for conventional therapies to control ventricular systolic dysfunction, including mechanical circulatory support, which moves potential heart-transplantation recipients to a listing status of higher priority. This results in longer waitlist times and greater mortality rates. Exception-status listing allows a pathway for this complex and anatomically heterogenous group of patients to be listed for heart transplantation at appropriately high listing status. Our study queried the United Network for Organ Sharing registry to evaluate trends in the use of exception-status listing among adults with congenital heart diseases awaiting heart transplantation. Uptrend in the use of exception-status listing precedes the new allocation system, but it has been greatest since changes were made in the allocation system. It continues to remain a vital pathway for adults with congenital heart disease (whose waitlist mortality rates are often not characterized adequately by using the waitlist-status criteria) timely access to heart transplantation.

Mental health disorders and emergency resource use and outcomes in ventricular assist device supported patients.

There are limited data describing the prevalence of mental health disorders (MHDOs) in patients with ventricular assist devices (VADs), or associations between MHDOs and resource use or outcomes. We used the Nationwide Emergency Department Sample administrative database to analyze 44,041 ED encounters for VAD-supported adults from 2010 to 2017, to assess the relationship between MHDOs and outcomes in this population. MHDO diagnoses were present for 23% of encounters, and were associated with higher charges and rates of admission, but lower mortality.

Ranolazine Improves Right Ventricular Function in Patients With Precapillary Pulmonary Hypertension: Results From a Double-Blind, Randomized, Placebo-Controlled Trial.

INTRODUCTION: A major outcome determinant in patients with precapillary pulmonary hypertension (PH) is right ventricular (RV) function. We studied the effect of ranolazine on RV function over 6 months using cardiovascular magnetic resonance (CMR) imaging in patients with precapillary PH (groups I, III, and IV). METHODS AND RESULTS: We enrolled patients with PH and RV dysfunction (CMR imaging ejection fraction [EF] of <45%) in a longitudinal, randomized, double-blinded, placebo controlled, multicenter study of ranolazine treatment. All enrolled patients were on stable PH-specific therapy. Enrolled patients were assessed using CMR imaging, New York Heart Association functional class, N-terminal pro brain natriuretic peptide, 6-minute walk test, and quality of life health outcomes at baseline and repeated at the end of treatment. The primary outcome was change in RVEF after 6 months of treatment. Analysis of covariance was used to analyze the longitudinal changes taking into account baseline values, age, and sex, based on per protocol population. Twenty-two patients were enrolled, and 9 patients completed follow-up CMR imaging after ranolazine treatment and 6 completed placebo treatment. There was significant increase in RVEF at end of treatment compared with baseline in the ranolazine group adjusted for baseline values, age, and sex. There were no statistically significant changes in secondary outcomes such as changes in New York Heart Association functional class, 6-minute walk distance, N-terminal pro brain natriuretic peptide, or quality of life measures. Ranolazine treated patients experienced a higher number of adverse events, but only one was discontinued owing to side effects. CONCLUSIONS: Ranolazine may improve RV function in patients with precapillary PH. Larger studies are needed to confirm the beneficial effects of ranolazine.

No survival benefit associated with waiting for non-lung donor heart transplants for adult recipients with congenital heart disease.

BACKGROUND: Adults with congenital heart disease (CHD) awaiting heart transplant (HT) have higher mortality and waitlist removal due to clinical deterioration than those without CHD. The selective use of non-lung donors (NLD) to recover donor pulmonary vasculature to assist in graft implantation may be a contributing factor and is supported by consensus statements despite the recent use of pericardium or graft material as an alternative in pulmonary vascular reconstruction. The impact of selecting NLD for CHD recipients on wait time and mortality has not been evaluated. METHODS/RESULTS: In the United Network for Organ Sharing (UNOS) Registry, 1271 HT recipients age ≥ 18 with CHD were identified between 1987 and 2016, 68% of which had NLDs. Prior to HT, NLD recipients were significantly less likely to be listed UNOS Status 1A, require mechanical ventilation, or intra-aortic balloon pump support. There was no difference in mean waitlist time (254 vs. 278 days, p = .31), 1-year mortality (82% vs. 80%, p = .81; adjusted odds ratio 1.32, 95% confidence interval [CI] 0.96-1.83, p = .08), or overall mortality (adjusted hazard ratio 1.08, 95% CI 0.86-1.36, p = .48) between recipients from NLD and concomitant lung donors. CONCLUSIONS: Adult CHD patients who are less critically ill or listed at a lower status are more likely to receive HT from NLD. There is no overall mortality benefit associated with this practice. While specific cases may necessitate waiting for NLD, programs need to re-evaluate whether this should remain a more widespread practice among CHD patients.

A comprehensive echocardiographic method for risk stratification in pulmonary arterial hypertension.

QUESTION ADDRESSED: Echocardiography is not currently considered as providing sufficient prognostic information to serve as an integral part of treatment goals in pulmonary arterial hypertension (PAH). We tested the hypothesis that incorporation of multiple parameters reflecting right heart function would improve the prognostic value of this imaging modality. METHODS AND MAIN RESULTS: We pooled individual patient data from a total of 517 patients (mean age 52±15 years, 64.8% females) included in seven observational studies conducted at five European and United States academic centres. Patients were subdivided into three groups representing progressive degrees of right ventricular dysfunction based on a combination of echocardiographic measurements, as follows. Group 1 (low risk): normal tricuspid annular plane systolic excursion (TAPSE) and nonsignificant tricuspid regurgitation (TR) (n=129); group 2 (intermediate risk): normal TAPSE and significant TR or impaired TAPSE and nondilated inferior vena cava (IVC) (n=256); group 3 (high risk): impaired TAPSE and dilated IVC (n=132). The 5-year cumulative survival rate was 82% in group 1, 63% in group 2 and 43% in group 3. Low-risk patients had better survival rates than intermediate-risk patients (log-rank Chi-squared 12.25; p<0.001) and intermediate-risk patients had better survival rates than high-risk patients (log-rank Chi-squared 26.25; p<0.001). Inclusion of other parameters such as right atrial area and pericardial effusion did not provide added prognostic value. ANSWER TO THE QUESTION: The proposed echocardiographic approach integrating the evaluation of TAPSE, TR grade and IVC is effective in stratifying the risk for all-cause mortality in PAH patients, outperforming the prognostic parameters suggested by current guidelines.

Treatment With Impella Increases the Risk of De Novo Aortic Insufficiency Post Left Ventricular Assist Device Implant.

BACKGROUND: Impella (Abiomed Inc, Danvers, MA) is a temporary mechanical support device positioned across the aortic valve, and can be used to support patient before LVAD implantation. There are no data on the incidence of aortic insufficiency (AI) in patients supported with Impella as a bridge to durable LVAD implantation. We sought to assess the incidence of AI in patients with Impella support as a bridge to durable left ventricular assist device (LVAD) implantation. METHODS: We reviewed all patients undergoing primary LVAD implantation at the University of Pennsylvania from January 2015 onward, comparing those supported with Impella as temporary mechanical support with those supported by either venoarterial extracorporeal life support or an intra-aortic balloon pump. We reviewed transthoracic echocardiography preoperatively, as well as at 1 week, 1, 3, 6, 9, and 12 months after LVAD implantation. RESULTS: A total of 215 echocardiograms were analyzed in 41 patients. Eleven patients were supported with Impella before LVAD implant-6 patients with Impella alone (5 with Impella CP, 1 with Impella 5.0) and 5 with Impella in conjunction with venoarterial extracorporeal life support (2 with Impella 2.5, 2 with Impella CP, and 1 with Impella 5.0). After LVAD implant, mild or moderate AI developed in 82% of patients supported with Impella (9 of 11) compared with 43% of those without Impella (13 of 30) (P = .038). CONCLUSIONS: Patients supported by Impella as a bridge to durable LVAD have a higher risk of developing AI. Further studies are needed to assess this risk as the use of the Impella increases.

Outcomes of catheter-directed versus systemic thrombolysis for the treatment of pulmonary embolism: A real-world analysis of national administrative claims.

Catheter-directed thrombolysis (CDT) and systemic thrombolysis (ST) are used to treat intermediate/high-risk pulmonary embolism (PE) in the absence of comparative safety and effectiveness data. We utilized a large administrative database to perform a comparative safety and effectiveness analysis of catheter-directed versus systemic thrombolysis. From the Optum® Clinformatics® Data Mart private-payer insurance claims database, we identified 100,744 patients hospitalized with PE between 2004 and 2014. We extracted demographic characteristics, high-risk PE features, components of the Elixhauser Comorbidity Index, and outcomes including intracranial hemorrhage (ICH), all-cause bleeding, and mortality among all patients receiving CDT and ST. We used propensity score methods to compare outcomes between matched cohorts adjusted for observed confounders. A total of 1915 patients (1.9%) received either CDT (n = 632) or ST (n = 1283). Patients in the CDT group had fewer high-risk features including less shock (5.4 vs 11.1%; p < 0.001) and cardiac arrest (6.8 vs 11.0%; p = 0.004). In 1:1 propensity-matched groups, ICH rates were 1.9% in both the CDT and ST groups (p = 1.0). All-cause bleeding was higher in the CDT group (15.9 vs 8.7%; p < 0.001), while in-hospital mortality was lower (6.5 vs 10.0%; p = 0.02). Among a nationally representative cohort of patients with PE at higher risk for mortality, CDT was associated with similar ICH rates, increased all-cause bleeding, and lower short and intermediate-term mortality when compared with ST. The competing risks and benefits of CDT in real-world practice suggest the need for large-scale randomized clinical trials with appropriate comparator arms.

Pulmonary Hypertension in Advanced Heart Failure: Assessment and Management of the Failing RV and LV.

PURPOSE OF REVIEW: In patients with heart failure with reduced ejection fraction, the presence of pulmonary hypertension (PH-LHD) has a significant impact on their prognosis. The purpose of this review is to explain the methods of diagnosing PH-LHD and then discuss the available therapeutic options. RECENT FINDINGS: We begin by examining the methods of assessment of PH-LHD-echocardiography, cardiopulmonary exercise testing, and right heart catheterization-with a particular focus on the importance of accurate measurement to ensure the proper determination of PH-LHD. We then focus primarily on management of PH-LHD, with an examination of trials of therapeutic options, use of mechanical circulatory support, and transplantation. This review highlights the complexities in diagnosis and management of PH-LHD. We outline a number of useful ways to maximize the yield of diagnostic testing, as well as give suggestions on the use of medical therapies, the role of both temporary mechanical support and left ventricular assist device, and finally the ways to best bridge these patients to transplantation.

Increased Pulmonary-Systemic Pulse Pressure Ratio Is Associated With Increased Mortality in Group 1 Pulmonary Hypertension.

BACKGROUND: Pulmonary arterial hypertension (PAH) is characterised by remodelling of the pulmonary vasculature leading to right ventricular (RV) failure. The failing RV, through interventricular uncoupling, deleteriously impacts the left ventricle and overall cardiac efficiency. We hypothesised that the ratio of the pulmonary artery pulse pressure to the systemic pulse pressure ("pulmonary-systemic pulse pressure ratio", or PS-PPR) would be associated with mortality in PAH. METHODS: We conducted a retrospective analysis of 262 patients in the National Institute of Health Primary Pulmonary Hypertension Registry (NIH-PPH). We evaluated the association between the PS-PPR and mortality after adjustment for the Pulmonary Hypertension Connection (PHC) risk equation. RESULTS: Among 262 patients (mean age 37.5±15.8years, 62.2% female), median PS-PPR was 1.04 (IQR 0.79-1.30). In the Cox proportional hazards regression model, each one unit increase in the PS-PPR was associated with more than a two-fold increase in mortality during follow-up (HR 2.06, 95% CI 1.40-3.02, p=0.0002), and this association of PS-PPR with mortality remained significant in the multivariable Cox model adjusted for the PHC risk equation, mean pulmonary artery pressure, and body mass index (BMI) (adjusted HR 1.81, 95% CI 1.13-2.88, p=0.01). Furthermore, PS-PPR in the upper quartile (>1.30) versus quartiles 1-3 was associated with a 68% increase in mortality after adjustment for these same covariates (adjusted HR 1.68, 95% CI 1.13-2.50, p=0.01). CONCLUSIONS: Pulmonary-systemic pulse pressure ratio, a marker of biventricular efficiency, is associated with survival in PAH even after adjustment for the PHC risk equation. Further studies are needed on the wider applications of PS-PPR in PAH patients.

Pulmonary Hypertension Due to Left Ventricular Cardiomyopathy: Is it the Result or Cause of Disease Progression?

PURPOSE OF REVIEW: The purpose of this review is to define pulmonary hypertension in the setting of left heart disease (PH-LHD), discuss its epidemiology and pathophysiology, and highlight the cause and effect relationship it has with disease progression in the setting of cardiomyopathy. RECENT FINDINGS: Both pulmonary hypertension (PH) and heart failure are becoming increasingly common. As such, PH-LHD is now the most common form of PH. The pathophysiology of the condition relates to backward transmission of elevated left ventricular filling pressures into the pulmonary circulation and, ultimately, right ventricular (RV) strain/dysfunction. It is evident that these pathophysiologic processes are both the effect and cause of left heart disease progression. In this review, we describe the complex relationship between disease progression in left ventricular cardiomyopathy and PH-LHD. Clinicians and researchers should take note of the importance of PH-LHD and RV dysfunction to appropriately risk stratify patients and develop therapies for the condition.

Galectin-3 Levels Are Elevated and Predictive of Mortality in Pulmonary Hypertension.

BACKGROUND: Galectin-3, a novel binding-lectin involved in inflammation and fibrosis, is elevated in heart failure and is independently predictive of mortality in this condition. We sought to evaluate galectin-3 levels and its prognostic value in patients with pulmonary hypertension (PH), a known inflammatory state, in the setting of pulmonary arterial hypertension (PAH) and in heart failure with preserved ejection fraction-associated PH (HFpEF-PH). METHODS: We measured galectin-3 levels in 76 patients with PH; 37 patients with PAH and 39 patients with HFpEF-PH. Baseline characteristics, and N-terminal prohormone of brain natriuretic peptide (NT-proBNP) levels were assessed. Univariate and multivariate analyses were used to assess the prognostic value of galectin-3. RESULTS: Median (IQR) galectin-3 (ng/mL) for the entire cohort was 24.65 (IQR=10.39, 32.90); 22.33 (IQR=18.94, 27.30) and 28.94 (IQR=21.67, 39.85) in the PAH and HFpEF-PH, respectively (p=0.07). After evaluation of the galectin-3 levels by tertile, mortality rates were 16% (4/25), 34.6% (9/26), and 48% (12/25) in tertiles 1-3, respectively, and Kaplan-Meier analysis revealed a significant increase in mortality across increasing galectin-3 tertiles (log-rank p=0.014). On Cox regression analysis, galectin-3 was a strong predictor of mortality on both univariate HR=2.09 per tertile (95% CI=1.21, 3.62 per tertile; p-trend=0.008) and multivariate analysis HR=2.19 per tertile (95% CI=1.06, 4.54; p-trend=0.035) after adjusting for age, sex, race, glomerular filtration rate (eGFR), NT-proBNP, medications, and aetiology of PH (PAH vs. HFpEF-PH). CONCLUSION: Galectin-3 is a strong, independent prognostic marker in PH, regardless of aetiology. Larger studies should further evaluate the role of galectin-3 as a prognostic biomarker and possible therapeutic target in PH.

Understanding Heart Failure.

Heart failure (HF) is a growing global health concern that affects more than 20 million people worldwide. With an ever-growing segment of the population over the age of 65, the prevalence of HF and its associated costs are expected to increase exponentially over the next decade. Advances in the understanding of the pathophysiology and treatment of HF have resulted in the ability to enhance both the quantity and the quality of life of patients with HF. This article reviews the current understanding of the pathophysiology, cause, classification, and treatment of HF and describes areas of uncertainty that demand future study.

Addition of angiotensin-converting enzyme inhibitors to beta-blockers has a distinct effect on hispanics compared with african americans and whites with heart failure and reduced ejection fraction: a propensity score-matching study.

BACKGROUND: There are currently no data on the efficacy of angiotensin-converting enzyme inhibitors (ACEis) in Hispanic patients with heart failure (HF) and reduced ejection fraction (HFrEF). We aimed to investigate the effect of adding ACEis to beta-blockers on mortality and hospitalization for HF exacerbation in patients with HFrEF stratified by race/ethnicity. METHODS AND RESULTS: From Montefiore Medical Center's 3 large hospitals, 618 consecutive patients with HFrEF (left ventricular ejection fraction [LVEF] <35%) who were on a beta-blocker were retrospectively identified. Patients were divided into 2 groups based on whether or not they were on an ACEi for 24 consecutive months. Propensity score matching including all baseline characteristics was performed and patients were then categorized into 3 groups: African Americans, Hispanics, and Whites/Caucasians. We evaluated 2-year all-cause mortality and 2-year hospitalization for HF exacerbation. Of 618 patients, 66% were categorized as ACEi and 34% as no-ACEi. Four hundred twenty-seven patients were matched 2:1 between the ACEi and no-ACEi groups. After matching, overall 2-year mortality and hospitalization rates were similar between ACEi and no-ACEi (12.4% vs 17.8%, hazard ratio [HR] 0.66, 95% confidence interval [CI] 0.38-1.16; P = .14; and 8.1% vs 9.5%, HR 0.84, 95% CI 0.44-1.60; P = .6; respectively). After stratifying patients based on race/ethnicity, ACEi demonstrated a lower 2-year mortality compared with no-ACEi in Hispanics (9.8% vs 28.4%, HR 0.33, 95% CI 0.13-0.87; P = .018) but not in African Americans (17.0% vs 11.8%, HR 0.94, 95% CI 0.34-2.65; P = .91) or Whites (9.2% vs 10.3%, HR 0.89, 95% CI 0.29-2.74; P = .83). Two-year hospitalization was not different between ACEi and no-ACEi in Hispanics, African Americans, or Whites (all P = NS). In multivariate analysis, ACEi therapy was an independent predictor of lower 2-year mortality (HR 0.33, 95% CI 0.12-0.89; P = .028) in Hispanics only. CONCLUSIONS: In this retrospective propensity-matched study of patients with HFrEF who were on a beta-blocker, ACEi therapy was associated with greater mortality reduction in Hispanic patients compared with African Americans and Whites. These findings need to be confirmed in large national studies that include a significant fraction of Hispanic patients.

Outcomes in World Health Organization group II pulmonary hypertension: mortality and readmission trends with systolic and preserved ejection fraction-induced pulmonary hypertension.

BACKGROUND: Heart failure with preserved ejection fraction (HFpEF) has been increasingly recognized as a leading cause of pulmonary hypertension (HFpEF-PH). It remains unknown how HFpEF-PH fares in relation to systolic HF (reduced ejection fraction)-induced PH (HFrEF-PH). Therefore, we sought to determine the long-term morbidity and mortality of HFpEF-PH and HFrEF-PH. METHODS AND RESULTS: We studied all patients over a 6-year period with symptomatic HF and severe PH (PASP ≥65 mm Hg) in The Bronx, New York. We classified patients as having either preserved (≥50%) or reduced (≤35%) left ventricular ejection fraction. Trends in mortality and HF readmission rates were defined in 650 patients (HFrEF-PH: n = 277; HFpEF-PH: n = 373). HFpEF-PH patients were older and more often female and white. HFrEF-PH patients were more often black, had ischemic cardiomyopathy, and were on typical HF drug regimens. Patients with HFpEF-PH had a significantly increased all-cause 5-year mortality (52% vs 42%; P = .024). HFpEF-PH was a significant predictor of mortality (adjusted hazard ratio 1.70; P = .012). Patients with HFrEF-PH had more HF readmissions (≥1) than patients with HFpEF-PH (28.6% vs 15%; P = .003), especially within the 1st year (9.1% vs 1.7%; P = .005). CONCLUSIONS: Patients with HFrEF-PH and HFpEF-PH have a significantly elevated long-term mortality, with HFpEF-PH having a higher 5-year mortality rate. These findings testify to the overall poor prognosis of World Health Organization Group II PH, especially HFpEF-PH.

Electrocardiographic Abnormalities and Their Association with Outcomes in Randomized Clinical Trials of Pulmonary Arterial Hypertension.

Rationale: Pulmonary arterial hypertension (PAH) is a progressive disease with manifestations including right atrial enlargement, right ventricular dysfunction, dilation, and hypertrophy. Electrocardiography (ECG) is a noninvasive, inexpensive test that is routinely performed in clinical settings. Prior studies have described separate abnormal findings in the electrocardiograms of patients with PAH. However, the role of composite ECG findings reflective of right heart disease (RHD) for risk stratification, clinical trial enrichment, and management of patients with PAH has not been explored. Objectives: To describe a pattern of RHD on ECG in patients with PAH and to investigate the association of this pattern with clinical measures of disease severity and outcomes. Methods: We harmonized individual participant data from 18 phase III randomized clinical trials of therapies for PAH (1998-2013) submitted to the U.S. Food and Drug Administration. RHD was defined as the presence of right ventricular hypertrophy, right axis deviation, right atrial enlargement, or right bundle branch block on ECG. Random effects linear regression, multilevel ordinal regression (cumulative link model), and Cox proportional hazards models were used to assess the association of RHD by ECG with 6-minute walk distance (6MWD), World Health Organization (WHO) functional class, and clinical worsening after a priori adjustment for age, sex, body mass index, and PAH etiology. Effect modification of treatment and ECG abnormalities was assessed by including an interaction term. Results: A total of 4,439 patients had baseline ECG, and 68% of patients had evidence of RHD. RHD on ECG was associated with higher pulmonary vascular resistance (P < 0.001) and higher mean pulmonary artery pressures (P < 0.001). Patients with RHD on ECG had 10 meters shorter 6MWD (P = 0.005) and worse WHO functional class (P < 0.001) at baseline. RHD on baseline ECG was associated with increased risk of clinical worsening (hazard ratio, 1.42; 95% confidence interval; 1.21, 1.67; P < 0.001). Patients with RHD had greater treatment effect in terms of 6MWD, WHO functional class, and time to clinical worsening than those without (P for interaction = 0.03, 0.001, and 0.03, respectively). Conclusions: RHD by ECG may be associated with worse outcomes and potentially greater treatment effect. Electrocardiograms could be an inexpensive, widely available noninvasive method to enrich clinical trial populations in PAH.