Novel Liver Injury Phenotypes and Outcomes in Clinical Trial Participants with Pulmonary Hypertension.

RATIONALE: Pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) cause right ventricular dysfunction which can impact other solid organs. However, the profiles and consequences of hepatic injury due to PAH and CTEPH have not been well-studied. OBJECTIVES: We aimed to identify underlying patterns of liver injury in a cohort of PAH and CTEPH patients enrolled in 15 randomized clinical trials conducted between 1998 and 2014. METHODS: We used unsupervised machine learning to identify liver injury clusters in 13 trials and validated the findings in two additional trials. We then determined whether these liver injury clusters were associated with clinical outcomes or treatment effect heterogeneity. MEASUREMENTS AND MAIN RESULTS: Our training dataset included 4,219 patients and our validation dataset included 1,756 patients with serum total bilirubin, alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, and albumin data. Using k-means clustering, we identified phenotypes with no liver injury, hepatocellular injury, cholestatic injury, and combined injury patterns. Patients in the cholestatic injury liver cluster had the shortest time to clinical worsening and the highest risk of mortality. The cholestatic injury group also experienced the greatest placebo-corrected treatment effect on six-minute walk distance. Randomization to the experimental arm transitioned patients to a healthier liver status. CONCLUSIONS: Liver injury was associated with adverse outcomes in patients with PAH and CTEPH. Randomization to active treatment had beneficial effects on liver health compared to placebo. The role of liver disease (often subclinical) in determining outcomes warrants prospective studies.

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.

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.

Novel Liver Injury Phenotypes and Outcomes in Pulmonary Arterial Hypertension.

Background: Pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) are disorders of the pulmonary vasculature that cause right ventricular dysfunction. Systemic consequences of right ventricular dysfunction include damage to other solid organs, such as the liver. However, the profiles and consequences of hepatic injury due to PAH and CTEPH have not been well-studied. Methods: We aimed to identify underlying patterns of liver injury in a cohort of PAH and CTEPH patients enrolled in 15 randomized clinical trials conducted between 1998 and 2012. We used unsupervised machine learning to identify liver injury clusters in 13 trials and validated the findings in two additional trials. We then determined whether these liver injury clusters were associated with clinical outcomes or treatment effect heterogeneity. Results: Our training dataset included 4,219 patients and our validation dataset included 1,756 patients with complete liver laboratory panels (serum total bilirubin, alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, and albumin). Using k-means clustering paired with factor analysis, we identified four unique liver phenotypes (no liver injury, hepatocellular injury, cholestatic injury, and combined injury patterns). Patients in the cholestatic injury liver cluster had the shortest time to clinical worsening and highest chance of worsening World Health Organization functional class. Randomization to the experimental arm was associated with a transition to healthier liver clusters compared to randomization to the control arm. The cholestatic injury group experienced the greatest placebo-corrected treatment benefit in terms of six-minute walk distance. Conclusions: Liver injury patterns were associated with adverse outcomes in patients with PAH and CTEPH. Randomization to active treatment of pulmonary hypertension in these clinical trials had beneficial effects on liver health compared to placebo. The independent role of liver disease (often subclinical) in determining outcomes warrants prospective studies of the clinical utility of liver phenotyping for PAH prognosis and contribution to clinical disease.

Heterogeneity of treatment effects by risk in pulmonary arterial hypertension.

BACKGROUND: It is currently unknown if disease severity modifies response to therapy in pulmonary arterial hypertension (PAH). We aimed to explore if disease severity, as defined by established risk-prediction algorithms, modified response to therapy in randomised clinical trials in PAH. METHODS: We performed a meta-analysis using individual participant data from 18 randomised clinical trials of therapy for PAH submitted to the United States Food and Drug Administration to determine if predicted risk of 1-year mortality at randomisation modified the treatment effect on three outcomes: change in 6-min walk distance (6MWD), clinical worsening at 12 weeks and time to clinical worsening. RESULTS: Of 6561 patients with a baseline US Registry to Evaluate Early and Long-Term PAH Disease Management (REVEAL 2.0) score, we found that individuals with higher baseline risk had higher probabilities of clinical worsening but no difference in change in 6MWD. We detected a significant interaction of REVEAL 2.0 risk and treatment assignment on change in 6MWD. For every 3-point increase in REVEAL 2.0 score, there was a 12.49 m (95% CI 5.86-19.12 m; p=0.001) greater treatment effect in change in 6MWD. We did not detect a significant risk by treatment interaction on clinical worsening with most of the risk-prediction algorithms. CONCLUSIONS: We found that predicted risk of 1-year mortality in PAH modified treatment effect as measured by 6MWD, but not clinical worsening. Our findings highlight the importance of identifying sources of treatment heterogeneity by predicted risk to tailor studies to patients most likely to have the greatest treatment response.

Mechanical thrombectomy versus catheter directed thrombolysis in patients with pulmonary embolism: A multicenter experience.

OBJECTIVES: Compare in-hospital outcomes of patients treated with either mechanical thrombectomy (MT) or catheter directed lysis (CDL) in treatment of acute pulmonary embolism (PE). METHODS: This is a multicenter, retrospective cohort study of patients undergoing MT or CDL for acute PE between 2014 and 2021. The primary outcome was the composite of in-hospital death, significant bleed, vascular complication, or need for mechanical support post-procedure. Secondary outcomes included the individual components of the composite outcome in addition to blood transfusions, invasive hemodynamics, echocardiographic data, and intensive care unit (ICU) utilization. RESULTS: 458 patients were treated for PE with 266 patients in the CDL arm and 192 patients in the MT arm. The primary composite endpoint was not significantly different between the two groups with CDL 12% versus MT 11% (p = 0.5). There was a significant difference in total length of ICU time required with more in the CDL group versus MT (3.8 ± 2.0 vs. 2.8 ± 3.0 days, p = 0.009). All other secondary end points showed no significant difference between the groups. CONCLUSIONS: In patients undergoing catheter directed treatment of PE, there was no difference between MT and CDL in terms of in-hospital mortality, bleeds, catheter-related complications, and hemodynamics.

Symptom phenotypes in pulmonary arterial hypertension: The PAH "symptome".

Women with pulmonary arterial hypertension (PAH) experience multiple symptoms, including dyspnea, fatigue, and sleep disturbance, that impair their health-related quality of life (HRQOL). However, we know little about phenotypic subgroups of patients with PAH with similar, concurrent, multiple symptoms. The objectives of this study were to define the "symptome" by symptom cluster phenotypes and compare characteristics such as biomarkers, cardiac structure and function (echocardiography), functional capacity (6-min walk distance), and HRQOL between the groups. This cross-sectional study included 60 women with PAH. Subjects completed an assessment battery: Pulmonary Arterial Hypertension Symptom Scale, Pittsburgh Sleep Quality Index, Multidimensional Dyspnea Profile, Patient-Reported Outcomes Measurement Information System (PROMIS®) Physical Function, PROMIS® Sleep-Related Impairment, and the emPHasis-10. Subjects also underwent transthoracic echocardiography, phlebotomy, 6-min walk distance, and actigraphy. The three symptoms of dyspnea, fatigue, and sleep disturbance were used to define the symptom clusters. Other PAH symptoms, plasma and serum biomarkers, cardiac structure and function (echocardiography), exercise capacity (6-min walk distance), sleep (actigraphy), and HRQOL were compared across phenotypes. The mean age was 50 ± 18 years, 51% were non-Hispanic white, 32% were non-Hispanic Black and 40% had idiopathic PAH. Cluster analysis identified Mild (n = 28, 47%), Moderate (n = 20, 33%), and Severe Symptom Cluster Phenotypes (n = 12, 20%). There were no differences for age, race, or PAH etiology between the phenotypes. WHO functional class (p < 0.001), norepinephrine levels (p = 0.029), right atrial pressure (p = 0.001), physical function (p < 0.001), sleep onset latency (p = 0.040), and HRQOL (p < 0.001) all differed significantly across phenotypes. We identified three distinctive symptom cluster phenotypes (Mild, Moderate, and Severe) for women with PAH that also differed by PAH-related symptoms, physical function, right atrial pressure, norepinephrine levels, and HRQOL. These phenotypes could suggest targeted interventions to improve symptoms and HRQOL in those most severely affected.

Delphi consensus recommendation for optimization of pulmonary hypertension therapy focusing on switching from a phosphodiesterase 5 inhibitor to riociguat.

Dual combination therapy with a phosphodiesterase-5 inhibitor (PDE5i) and endothelin receptor antagonist is recommended for most patients with intermediate-risk pulmonary arterial hypertension (PAH). The RESPITE and REPLACE studies suggest that switching from a PDE5i to a soluble guanylate cyclase (sGC) activator may provide clinical improvement in this situation. The optimal approach to escalation or transition of therapy in this or other scenarios is not well defined. We developed an expert consensus statement on the transition to sGC and other treatment escalations and transitions in PAH using a modified Delphi process. The Delphi process used a panel of 20 physicians with expertise in PAH. Panelists answered three questionnaires on the management of treatment escalations and transitions in PAH. The initial questionnaire included open-ended questions. Later questionnaires consolidated the responses into statements that panelists rated on a Likert scale from -5 (strongly disagree) to +5 (strongly agree) to determine consensus. The Delphi process produced several consensus recommendations. Escalation should be considered for patients who are at high risk or not achieving treatment goals, by adding an agent from a new class, switching from oral to parenteral prostacyclins, or increasing the dose. Switching to a new class or within a class should be considered if tolerability or other considerations unrelated to efficacy are affecting adherence. Switching from a PDE5i to an SGC activator may benefit patients with intermediate risk who are not improving on their present therapy. These consensus-based recommendations may be helpful to clinicians and beneficial for patients when evidence-based guidance is unavailable.

BREEZE: Open-label clinical study to evaluate the safety and tolerability of treprostinil inhalation powder as Tyvaso DPI™ in patients with pulmonary arterial hypertension.

Inhaled treprostinil is an approved therapy for pulmonary arterial hypertension (PAH) and pulmonary hypertension associated with interstitial lung disease in the United States. Studies have confirmed the robust benefits and safety of nebulized inhaled treprostinil, but it requires a time investment for nebulizer preparation, maintenance, and treatment. A small, portable treprostinil dry powder inhaler has been developed for the treatment of PAH. The primary objective of this study was to evaluate the safety and tolerability of treprostinil inhalation powder (TreT) in patients currently treated with treprostinil inhalation solution. Fifty-one patients on a stable dose of treprostinil inhalation solution enrolled and transitioned to TreT at a corresponding dose. Six-minute walk distance (6MWD), device preference and satisfaction (Preference Questionnaire for Inhaled Treprostinil Devices [PQ-ITD]), PAH Symptoms and Impact (PAH-SYMPACT®) questionnaire, and systemic exposure and pharmacokinetics for up to 5 h were assessed at baseline for treprostinil inhalation solution and at Week 3 for TreT. Adverse events (AEs) were consistent with studies of inhaled treprostinil in patients with PAH, and there were no study drug-related serious AEs. Statistically significant improvements occurred in 6MWD, PQ-ITD, and PAH-SYMPACT. Forty-nine patients completed the 3-week treatment phase and all elected to participate in an optional extension phase. These results demonstrate that, in patients with PAH, transition from treprostinil inhalation solution to TreT is safe, well-tolerated, and accompanied by statistically significant improvements in key clinical assessments and patient-reported outcomes with comparable systemic exposure between the two formulations at evaluated doses (trial registration: clinicaltrials.gov identifier: NCT03950739).

BMI and Treatment Response in Patients With Pulmonary Arterial Hypertension: A Meta-analysis.

BACKGROUND: Obesity is increasingly prevalent in pulmonary arterial hypertension (PAH) but is associated with improved survival, creating an "obesity paradox" in PAH. It is unknown if the improved outcomes could be attributable to obese patients deriving a greater benefit from PAH therapies. RESEARCH QUESTION: Does BMI modify treatment effectiveness in PAH? STUDY DESIGN AND METHODS: Using individual participant data, a meta-analysis was conducted of phase III, randomized, placebo-controlled trials of treatments for PAH submitted for approval to the U.S. Food and Drug Administration from 2000 to 2015. Primary outcomes were change in 6-min walk distance (6MWD) and World Health Organization (WHO) functional class. RESULTS: A total of 5,440 participants from 17 trials were included. Patients with overweight and obesity had lower baseline 6MWD and were more likely to be WHO functional class III or IV. Treatment was associated with a 27.01-m increase in 6MWD (95% CI, 21.58-32.45; P < .001) and lower odds of worse WHO functional class (OR, 0.58; 95% CI, 0.48-0.70; P < .001). For every 1 kg/m2 increase in BMI, 6MWD was reduced by 0.66 m (P = .07); there was no significant effect modification of treatment response in 6MWD according to BMI (P for interaction = .34). Higher BMI was not associated with odds of WHO functional class at end of follow-up; however, higher BMI attenuated the treatment response such that every 1 kg/m2 increase in BMI increased odds of worse WHO functional class by 3% (OR, 1.03; P for interaction = .06). INTERPRETATION: Patients with overweight and obesity had lower baseline 6MWD and worse WHO functional class than patients with normal weight with PAH. Higher BMI did not modify the treatment response for change in 6MWD, but it attenuated the treatment response for WHO functional class. PAH trials should include participants representative of all weight groups to allow for assessment of treatment heterogeneity and mechanisms.

Advanced airway management and respiratory care in decompensated pulmonary hypertension.

Meticulous risk stratification is essential when considering intubation of a patient with decompensated pulmonary hypertension (dPH). It is paramount to understand both the pathophysiology of dPH (and associated right ventricular failure) and the complications related to a high-risk intubation before attempting the procedure. There are few recommendations in this area and the literature, guiding these recommendations, is limited to expert opinion and very few case reports/case series. This review will discuss the complex pathophysiology of dPH, the complications associated with intubation, the debates surrounding induction agents, and the available options for the intubation procedure, with specific emphasis on the emerging role for awake fiberoptic intubation. All patients should be evaluated for candidacy for veno-arterial extracorporeal membrane oxygen as a bridge to recovery, lung transplantation, or pulmonary endarterectomy prior to intubation. Only an experienced proceduralist who is both comfortable with high-risk intubations and the pathophysiology of dPH should perform these intubations.

Secular and Regional Trends among Pulmonary Arterial Hypertension Clinical Trial Participants.

Rationale: The population of patients with pulmonary arterial hypertension (PAH) has evolved over time from predominantly young White women to an older, more racially diverse and obese population. Whether these changes are reflected in clinical trials is not known. Objectives: To determine secular and regional trends among PAH trial participants. Methods: We performed a pooled cohort analysis using harmonized data from phase III clinical trials of PAH therapies submitted to the U.S. Food and Drug Administration. We used mixed-effects linear and logistic regression to assess regional differences in participant age, sex, body habitus, and hemodynamics over time. Results: A total of 6,599 participants were enrolled in 18 trials between 1998 and 2013; 78% were female. The mean age of participants in North America, Europe, and Latin America at the time of study start increased by 2.09 (95% confidence interval [CI], 0.67-3.51), 1.62 (95% CI, 0.24-3.00), and 4.75 (95% CI, 2.29-7.21) years per 5 years, respectively (P = 0.01). Body mass index at the time of study start increased by 0.72 kg/m2 per 5 years (95% CI, 0.44-0.99; P < 0.001) across all regions. Eighty-five percent of participants in early studies were non-Hispanic White, but this decreased over time to 70%. Ninety-seven percent of Asians and 74% of Hispanics in the sample were recruited from Asia and Latin America. Conclusions: Patients enrolled in more recent PAH therapy trials are older and more obese, mirroring the changing epidemiology of observational cohorts. However, these trends varied by geographic region. PAH cohorts remain predominantly female, presenting challenges for generalizability to male patients. Although the proportion of non-White participants increased over time, this was primarily through recruitment in Asia and Latin America.

Intermediate-Term Outcomes for Patients with Submassive Pulmonary Embolism Treated With Catheter-Directed Thrombolysis.

OBJECTIVE: We aimed to assess the intermediate-term outcomes for patients receiving catheter-directed thrombolysis (CDT) for submassive pulmonary embolism (PE). BACKGROUND: Previous research has shown improvements in right ventricular (RV) function and dilation at 24 hours when CDT was used to treat submassive PE. METHODS: Consecutive patients presenting with submassive PE treated with directed t-PA infusion at a single center were identified and included in this study. Outcomes included cardiovascular mortality, RV function by echocardiogram, 30-day readmission, and major bleeding. RESULTS: The study population was 79 patients with submassive PE; 46% were men, with an average age of 58 years and an average pulmonary embolism severity index (PESI) score of 108. One patient died of cardiovascular causes during the index hospitalization. There were no additional deaths within 30 days of admission. The observed 30-day mortality rate was low compared with that predicted by PESI (1.3% vs 4.0%-11.4%). Fifty-two patients had follow-up echocardiography available for evaluation after CDT. Of these, 62% showed return to normal RV function and size, and 19% demonstrated mild residual RV dysfunction or dilation. Eight patients (10%) had a hospital readmission within 30 days of discharge, including 6 admissions due to cardiopulmonary complications or minor bleeding and 2 for non-cardiopulmonary or bleeding-related reasons. The observed readmission rate of 10% was similar to historic rates of 12.8%. CONCLUSIONS: Intermediate-term follow-up for CDT demonstrates high success rates with low adverse event rates. Further randomized data are needed to study the long-term benefits of CDT.

Atrial arrhythmias in chronic lung disease-associated pulmonary hypertension.

Atrial arrhythmias are common during episodes of acute respiratory failure in patients with chronic lung disease-associated pulmonary hypertension. Expert opinion suggests that management of atrial arrhythmias in patients with pulmonary hypertension should aim to restore sinus rhythm. This is clinically challenging in pulmonary hypertension patients with coexisting chronic lung disease, as there is controversy on the use of rhythm control agents; generally, in regard to either their pulmonary toxicity profile or the lack of evidence supporting their use. Rate control methods are largely focused on the use of beta blockers and calcium channel blockers. Concerns regarding their use involve their negative inotropic properties in cor pulmonale, the risk of bronchospasm associated with beta blockers, and the potential for ventilation/perfusion mismatching associated with calcium channel blockers. While digoxin has been associated with promising outcomes during acute right ventricular failure, there is limited evidence to suggest its routine use. Electrical cardioversion is associated with a high failure rate and it frequently requires multiple attempts. Radiofrequency catheter ablation is a more definitive approach, but concerns surrounding mechanical ventilation and sedation limit its applicability in decompensated pulmonary hypertension. Individual approaches are needed to address atrial arrhythmia management during acute episodes of respiratory failure.

Interstitial Lung Disease Associated Acute Respiratory Failure Requiring Invasive Mechanical Ventilation: A Retrospective Analysis.

BACKGROUND: Interstitial Lung Disease [ILD] patients requiring Invasive Mechanical Ventilation [IMV] for Acute Respiratory Failure [ARF] are known to have a poor prognosis. Few studies have investigated determinants of outcomes and the utility of trialing Non-Invasive Positive Pressure Ventilation [NIPPV] prior to IMV to see if there are any effect[s] on mortality or morbidity. METHODS: A retrospective study was designed using patients at four different intensive care units within one health care system. The primary objective was to determine if there are differences in outcomes for in-hospital and one-year mortality between patients who undergo NIPPV prior to IMV and those who receive only IMV. A secondary objective was to identify potential determinants of outcomes. RESULTS: Out of 54 ILD patients with ARF treated with IMV, 20 (37.0%) survived until hospital discharge and 10 (18.5%) were alive at one-year. There was no significant mortality difference between patients trialed on NIPPV prior to IMV and those receiving only IMV. Several key determinants of outcomes were identified with higher mortality, including higher ventilatory support, idiopathic pulmonary fibrosis (IPF) subtype, high dose steroids, use of vasopressors, supraventricular tachycardias (SVTs), and higher body mass index. CONCLUSION: Considering that patients trialed on NIPPV prior to IMV were associated with no mortality disadvantage to patients treated with only IMV, trialing patients on NIPPV may identify responders and avoid complications associated with IMV. Increased ventilator support, need of vasopressors, SVTs, and high dose steroids reflect higher mortality and palliative care involvement should be considered as early as possible if a lung transplant is not an option.

Invasive hemodynamic assessment of patients with submassive pulmonary embolism.

OBJECTIVES: To investigate the invasive hemodynamics in patients with intermediate-risk pulmonary embolism (PE) and the change that occurs with catheter-directed thrombolysis (CDT). BACKGROUND: Intermediate-risk PE is associated with right ventricular strain and worse outcomes yet the invasive hemodynamics have not been well described. METHODS: Ninety-two consecutive patients with intermediate-risk PE referred for CDT at two tertiary medical centers with Pulmonary Embolism Response Teams were included in this prospective cohort study. Hemodynamics at baseline and after CDT therapy was measured. Patients with cardiac index (CI) ≤1.8 L min-1 m-2 were compared to those without shock (CI > 1.8). Linear regression analysis was performed to study the relationship between clinical variables and low CI. RESULTS: Thirty-seven out of 92 (40%) had a CI less than 1.8 L min-1 m-2 . When comparing the low CI to the normal CI groups, most demographics, vital signs, biomarkers, and PE severity index (PESI) scores were similar. The low CI group had more females and slightly lower systolic blood pressures although still in the normal range (122 vs. 132 mmHg, p = .026). Treatment with CDT was associated with significant improvement in CI, heart rate, and pulmonary artery pressures in both groups. Linear regression analysis did not reveal a strong correlation between CI and noninvasive metrics such as heart rate, blood pressure, or PESI score. CONCLUSIONS: Forty percent of patients with submassive PE had a depressed CI and treatment with CDT lead to hemodynamic improvements. Invasive hemodynamics may help better identify higher risk patients and guide therapy.