Proinflammatory Events in Right Ventricular Damage During Pulmonary Embolism: Effects of Treatment With Ketorolac in Rats

C-reactive Protein and Risk of Right Ventricular Dysfunction and Mortality in Patients With Acute Symptomatic Pulmonary Embolism

BACKGROUND

Right ventricle (RV) dysfunction increases the risk of death from pulmonary embolism (PE). C-reactive protein (CRP) might identify RV inflammation and dysfunction in patients with PE.

METHODS

This cohort study enrolled consecutive stable patients with acute PE between 2017 and 2023. We stratified patients by quartiles of CRP. We evaluated the association between CRP quartiles and the presence of RV dysfunction, and used multivariable models to assess for an association between CRP and the outcomes of all-cause and PE-specific mortality during the 30 days of follow-up after PE diagnosis.

RESULTS

The study included 633 stable patients with PE. Patients without RV dysfunction had significantly lower median (IQR) CRP levels compared with patients with RV dysfunction (n=509, 31.7 [10.0-76.4]mg/L vs n=124, 45.4 [16.0-111.4]mg/L; P=0.018). CRP showed a statistically significant positive association with the presence of RV dysfunction (P<0.01). On multivariable analysis, CRP level was not significantly associated with 30-day all-cause mortality (adjusted odds ratio [OR] per mg/L increment, 1.00; 95% CI, 1.00-1.01; P=0.095), but higher CRP was associated with significantly higher PE-related mortality (adjusted OR, 1.01; 95% CI, 1.00-1.01; P=0.026). Compared with patients in CRP quartile 1, patients in quartiles 2, 3, and 4 had a stepwise increase in the adjusted odds of 30-day all-cause death of 2.41 (P=0.148), 3.04 (P=0.062), and 3.15 (P=0.052), respectively.

CONCLUSIONS

As an indicator of RV dysfunction, CRP may improve risk stratification algorithms for hemodynamically stable patients with acute symptomatic PE.

IL-1β-mediated adaptive reprogramming of endogenous human cardiac fibroblasts to cells with immune features during fibrotic remodeling

The source and roles of fibroblasts and T-cells during maladaptive remodeling and myocardial fibrosis in the setting of pulmonary arterial hypertension (PAH) have been long debated. We demonstrate, using single-cell mass cytometry, a subpopulation of endogenous human cardiac fibroblasts expressing increased levels of CD4, a helper T-cell marker, in addition to myofibroblast markers distributed in human fibrotic RV tissue, interstitial and perivascular lesions in SUGEN/Hypoxia (SuHx) rats, and fibroblasts labeled with pdgfrα CreERt2/+ in R26R-tdTomato mice. Recombinant IL-1β increases IL-1R, CCR2 receptor expression, modifies the secretome, and differentiates cardiac fibroblasts to form CD68-positive cell clusters. IL-1β also activates stemness markers, such as NANOG and SOX2, and genes involved in dedifferentiation, lymphoid cell function and metabolic reprogramming. IL-1β induction of lineage traced primary mouse cardiac fibroblasts causes these cells to lose their fibroblast identity and acquire an immune phenotype. Our results identify IL-1β induced immune-competency in human cardiac fibroblasts and suggest that fibroblast secretome modulation may constitute a therapeutic approach to PAH and other diseases typified by inflammation and fibrotic remodeling.

Perioperative cardiovascular pathophysiology in patients undergoing lung resection surgery: a narrative review

Although thoracic surgery is understood to confer a high risk of postoperative respiratory complications, the substantial haemodynamic challenges posed are less well appreciated. This review highlights the influence of cardiovascular comorbidity on outcome, reviews the complex pathophysiological changes inherent in one-lung ventilation and lung resection, and examines their influence on cardiovascular complications and postoperative functional limitation. There is now good evidence for the presence of right ventricular dysfunction postoperatively, a finding that persists to at least 3 months. This dysfunction results from increased right ventricular afterload occurring both intraoperatively and persisting postoperatively. Although many patients adapt well, those with reduced right ventricular contractile reserve and reduced pulmonary vascular flow reserve might struggle. Postoperative right ventricular dysfunction has been implicated in the aetiology of postoperative atrial fibrillation and perioperative myocardial injury, both common cardiovascular complications which are increasingly being appreciated to have impact long into the postoperative period. In response to the physiological demands of critical illness or exercise, contractile reserve, flow reserve, or both can be overwhelmed resulting in acute decompensation or impaired long-term functional capacity. Aiding adaptation to the unique perioperative physiology seen in patients undergoing thoracic surgery could provide a novel therapeutic avenue to prevent cardiovascular complications and improve long-term functional capacity after surgery.

Outcome of patients with acute symptomatic pulmonary embolism and psychiatric disorders

OBJECTIVE

To address the association between psychiatric disorders and short-term outcomes after acute symptomatic pulmonary embolism (PE).

METHODS

We identified adults with PE enrolled in the RIETE registry between December 1, 2013, and January 31, 2019. Using multinomial regression, we assessed the association between a history of psychiatric disorders and the outcomes of all-cause mortality, PE-related mortality, and venous thromboembolism recurrence and bleeding rates through 30 days after initiation of treatment. We also examined the impact of depression on all-cause and PE-specific mortality.

RESULTS

Among 13,120 patients diagnosed with acute PE, 16.1% (2115) had psychiatric disorders and 4.2% died within the first 30-days of follow-up. Patients with psychiatric disorders had increased odds for all-cause (adjusted odds ratio [OR] 1.50; 95% CI, 1.21 to 1.86; P < 0.001) and PE-related mortality (adjusted OR 1.64; 95% CI, 1.09 to 2.48; P = 0.02) compared to those without psychiatric disorders. Multinomial logistic regression showed a non-significant trend toward lower risk of recurrences for patients with psychiatric disorders (adjusted OR 0.49; 95% CI, 0.21 to 1.15; P = 0.10). Psychiatric disorders were not significantly associated with increased odds for major bleeds during follow-up (adjusted OR 1.09; 95% CI, 0.85 to 1.40; P = 0.49). Results were consistent in a sensitivity analysis that only considered patients with a diagnosis of depression.

CONCLUSIONS

In patients with acute PE, history of psychiatric disorders might predict all-cause and PE-related death in the ensuing month after diagnosis.

Effect of metabolic syndrome on mean pulmonary arterial pressures in patients with acute pulmonary embolism treated with catheter-directed thrombolysis

BACKGROUND

Metabolic syndrome (MetS) has been associated with a procoagulant and hypofibrinolytic state. Current data exploring the role of MetS in venous thromboembolism (VTE) are limited. The objective was to measure the prevalence of MetS in patients with acute PE receiving catheter-directed thrombolysis (CDT) and to investigate its effect on mean pulmonary arterial pressure and overall treatment success.

METHODS

We used a 3-year prospective registry of ED patients with acute PE with severity qualifying for activation of a PE response team (PERT). All patients had CDT with catheter-measured mPAP and angiography. The presence or absence of MetS components were extracted from chart review based on the following criteria: 1. body mass index (BMI) >30 kg/m²; 2. diagnosed hypertension; 3. diabetes mellitus (including HbA1c >6.5%) and; 4. dyslipidemia (including triglycerides >150 mg/dL or high-density lipoprotein <40 mg/dL).

RESULTS

Of the 134 patients, 85% met the criteria for at least one of four MetS components, with obesity being most common, present in 71%. Results demonstrated a positive concordance between the number of criteria for MetS and MPAP, both pre- and post-fibrinolysis, as pressures tended to increase with each additional MetS criterion. Multivariate regression analysis determined age (-), BMI (+) and hypertension (+) to be significant independent predictor variables for mPAP.

CONCLUSIONS

MetS was common in patients with more severe manifestations of PE and was associated with higher mPAP values both at diagnosis and following treatment with CDT.

Assessment of Right Ventricular Function in the Research Setting: Knowledge Gaps and Pathways Forward. An Official American Thoracic Society Research Statement

BACKGROUND

Right ventricular (RV) adaptation to acute and chronic pulmonary hypertensive syndromes is a significant determinant of short- and long-term outcomes. Although remarkable progress has been made in the understanding of RV function and failure since the meeting of the NIH Working Group on Cellular and Molecular Mechanisms of Right Heart Failure in 2005, significant gaps remain at many levels in the understanding of cellular and molecular mechanisms of RV responses to pressure and volume overload, in the validation of diagnostic modalities, and in the development of evidence-based therapies.

METHODS

A multidisciplinary working group of 20 international experts from the American Thoracic Society Assemblies on Pulmonary Circulation and Critical Care, as well as external content experts, reviewed the literature, identified important knowledge gaps, and provided recommendations.

RESULTS

This document reviews the knowledge in the field of RV failure, identifies and prioritizes the most pertinent research gaps, and provides a prioritized pathway for addressing these preclinical and clinical questions. The group identified knowledge gaps and research opportunities in three major topic areas: 1) optimizing the methodology to assess RV function in acute and chronic conditions in preclinical models, human studies, and clinical trials; 2) analyzing advanced RV hemodynamic parameters at rest and in response to exercise; and 3) deciphering the underlying molecular and pathogenic mechanisms of RV function and failure in diverse pulmonary hypertension syndromes.

CONCLUSIONS

This statement provides a roadmap to further advance the state of knowledge, with the ultimate goal of developing RV-targeted therapies for patients with RV failure of any etiology.

Aggressive Treatment of Intermediate-Risk Patients with Acute Symptomatic Pulmonary Embolism

Contemporary studies of acute pulmonary embolism (PE) have evaluated the role of thrombolytics in intermediate-risk PE. Significant findings are that thrombolytic therapy may prevent hemodynamic deterioration and all-cause mortality but increases major bleeding. Benefits and harms are finely balanced with no convincing net benefit from thrombolytic therapy among unselected patients. Among patients with intermediate risk PE, additional prognostic factors or subtle hemodynamic changes might alter the risk-benefit assessment in favor of thrombolytic therapy before obvious hemodynamic instability.

Impact of chronic right ventricular pressure overload in short-term outcomes of acute pulmonary embolism: A retrospective analysis

PURPOSE

Evaluate the association between chronic right ventricle (RV) dysfunction by transthoracic echocardiogram (TTE) and outcomes in patients with acute pulmonary embolism (PE).

METHODS

This was a retrospective analysis of TTE findings in acute PEs. TTEs were used to classify the presence of chronic right ventricular pressure overload (RPVO), defined as RV hypertrophy or RV systolic pressure (RVSP) >50 mmHg, acute RVPO, defined as RV dysfunction not meeting the chronic RVPO definition, or no RV dysfunction. The primary outcome was a composite of death or need for advanced PE therapies at 7 days.

RESULTS

Of 466 patients, 288 had evidence of RV dysfunction. Thirty percent (140) had evidence of chronic RVPO and 148 patients had evidence of acute RVPO. Chronic RVPO patients were older (P = .004), more likely to have COPD, and had lower heart rates and troponin-t values. The acute RVPO patients included more women and were less likely to have a prior PE. There was no difference in outcomes between the acute and chronic RVPO cohorts.

CONCLUSIONS

Chronic RVPO patients had lower heart rates and troponin-t values. Despite these differences there were no differences in need for advanced therapeutic interventions or 7 day mortality.

Comparison of acute and convalescent biomarkers of inflammation in patients with acute pulmonary embolism treated with systemic fibrinolysis vs. placebo

: Previous studies have associated biomarkers indicative of acute inflammation with pulmonary embolism, which may amplify coagulation, inhibit fibrinolysis and increase risk of venous thromboembolism (VTE) recurrence. The aim of this study was to measure inflammatory and hemostatic biomarkers in acute submassive pulmonary embolism at diagnosis and 3-month follow-up and to test the impact of treatment with fibrinolysis. Secondary analysis of a multicenter, double-blinded, randomized controlled trial including patients with submassive pulmonary embolism. Blood samples were obtained within 24 h of diagnosis and prior to bolus-dose tenecteplase (TNK) or placebo; all patients received standard anticoagulation and blood was redrawn 3 months later. Plasma concentrations of inflammatory [Interleukin 6 (IL-6), C-reactive protein (CRP), myeloperoxidase (MPO)] and hemostatic [plasminogen activator inhibitor-1 (PAI-1), fibrinogen, thrombin-activatable fibrinolysis inhibitor and D-dimer] biomarkers were quantified. The median values of the biomarkers of inflammation (IL-6, CRP, MPO) were all significantly decreased at 3-month follow-up, ranging from a 60 to 91% reduction over this time period. Concentrations of PAI-1 and fibrinogen did not change significantly. D-dimer concentration at 3-month follow-up was lower in patients treated with fibrinolysis vs. placebo and appeared to have a trend toward significance (placebo 310 vs. TNK 220 ng/ml, P = 0.051). Acute pulmonary embolism causes marked but transient inflammation, as demonstrated by the significant elevation in the inflammatory biomarkers at diagnosis, followed by their reduction in more than 80% of patients at 3-month follow-up.

Inflammatory Mediators Drive Adverse Right Ventricular Remodeling and Dysfunction and Serve as Potential Biomarkers

Adverse right ventricular (RV) remodeling leads to ventricular dysfunction and failure that represents an important determinant of outcome in patients with pulmonary hypertension (PH). Recent evidence indicates that inflammatory activation contributes to the pathogenesis of adverse RV remodeling and dysfunction. It has been shown that accumulation of inflammatory cells such as macrophages and mast cells in the right ventricle is associated with maladaptive RV remodeling. In addition, inhibition of inflammation in animal models of RV failure ameliorated RV structural and functional impairment. Furthermore, a number of circulating inflammatory mediators have been demonstrated to be associated with RV performance. This work reviews the role of inflammation in RV remodeling and dysfunction and discusses anti-inflammatory strategies that may attenuate adverse structural alterations while promoting improvement of RV function.

Diclofenac for reversal of right ventricular dysfunction in acute normotensive pulmonary embolism: A pilot study

BACKGROUND

The inflammatory response associated with acute pulmonary embolism (PE) contributes to the development of right ventricular (RV) dysfunction. Nonsteroidal anti-inflammatory drugs (NSAIDs) may facilitate the reversal of PE-associated RV dysfunction.

METHODS

We randomly assigned normotensive patients who had acute PE associated with echocardiographic RV dysfunction and normal systemic blood pressure to receive intravenous (IV) diclofenac (two doses of 75mg in the first 24h after diagnosis) or IV placebo. All patients received standard anticoagulation with subcutaneous low-molecular-weight heparin (LMWH) and an oral vitamin K antagonist. RV dysfunction was defined by the presence of, at least, two of the following criteria: i) RV diastolic diameter>30mm in the parasternal window; ii) RV diameter>left ventricle diameter in the apical or subcostal space; iii) RV free wall hypokinesis; and iv) estimated pulmonary artery systolic pressure>30mmHg. Persistence of RV dysfunction at 48h and 7days after randomization were the primary and secondary efficacy outcomes, respectively. The primary safety outcome was major bleeding within 7days after randomization.

RESULTS

Of the 34 patients randomly assigned to diclofenac or placebo, the intention-to-treat analysis showed persistent RV dysfunction at 48h in 59% (95% confidence interval [CI], 33-82%) of the diclofenac group and in 76% (95% CI, 50-93%) of the placebo group (difference in risk [diclofenac minus standard anticoagulation], -17 percentage points; 95% CI, -47 to 17). Similar proportions (35%) of patients in the diclofenac and placebo groups had persistent RV dysfunction at 7days. Major bleeding occurred in none of patients in the diclofenac group and in 5.9% (95% CI, 0.2-29%) of patient in the placebo group.

CONCLUSIONS

Due to slow recruitment, our study is inconclusive as to a potential benefit of diclofenac over placebo to reverse RV dysfunction in normotensive patients with acute PE.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01590342.

Recent Progress in Research on the Pathogenesis of Pulmonary Thromboembolism: An Old Story with New Perspectives

Pulmonary thromboembolism (PTE) is part of a larger clinicopathological entity, venous thromboembolism. It is also a complex, multifactorial disorder divided into four major disease processes including venous thrombosis, thrombus in transit, acute pulmonary embolism, and pulmonary circulation reconstruction. Even when treated, some patients develop chronic thromboembolic pulmonary hypertension. PTE is also a common fatal type of pulmonary vascular disease worldwide, but earlier studies primarily focused on the pathological changes in the blood component of the disease. With contemporary advances in molecular and cellular biology, people are becoming increasingly aware of coagulation pathways, the function of vascular smooth muscle cells, microparticles, and the inflammatory pathways that play key roles in PTE. Combined hypoxia and immune research has revealed that PTE should be regarded as a class of complex diseases caused by multiple factors involving the vascular microenvironment and vascular cell dysfunction.

Differential effect of mild and severe pulmonary embolism on the rat lung transcriptome

BACKGROUND

Pulmonary thromboembolism (PTE) is a common diagnosis and a leading cause of cardiovascular morbidity and mortality. A growing literature has associated PE with systemic inflammation, and global hyper-coagulability, which contribute to lung remodeling and clot recurrence. The source and mechanism of inflammation remains unstudied. In humans, inhibition of cholesterol synthesis with statins decreases biomarkers of inflammation. We test the differential effect of pulmonary vascular occlusion during mild and severe pulmonary embolism on the lung transcriptome.

METHODS

Experimental PE was induced in adult male rats by injection of 25 micron polystyrene microspheres into the jugular vein. The effect of Mild PE, (2-h right ventricular systolic pressure [RVSP] normal, 18-h RVSP 44 mmHg) and Severe PE (2-h RVSP > 50 mmHg; 18-h RVSP 44 mmHg) on lungs was assessed by measuring transcriptome-wide changes in gene expression by DNA microarrays.

RESULTS

Severe PE was associated with a large change in lung gene expression and in the expression of KEGG pathways and other gene functional annotation groups. Mild PE was also associated with a large number of significant changes in gene expression and in the expression of KEGG pathways and gene functional annotation groups, even after only 2 h of PE. Up-regulated pathways included increased adipocytokine, chemokine and cytokine signaling as well as cholesterol synthesis.

CONCLUSIONS

Mild PE without acute pulmonary hypertension (PH) increased lung gene expression of inflammatory pathways, including increased cholesterol synthesis. These data indicate that even mild persistent pulmonary vascular occlusion is capable of inciting an inflammatory response from the lung. These data imply the detrimental effect of unresolved pulmonary obstruction from PE.

Inflammation in venous thromboembolism: Cause or consequence?

Venous thromboembolism (VTE) which includes deep vein thrombosis (DVT) and pulmonary thromboembolism (PTE) is a moderately common disease especially in elderly population with high rate of recurrence and complications. Evidence is accumulating that VTE is not restricted to coagulation system and immune system appears to be involved in formation and resolution of thrombus. The present study was aimed at reviewing current evidences on immune system abnormalities such as alterations in cytokines, chemokines and immune cells. Also, current evidences suggest that; a, inflammation in general functions as a double-edged sword, b, inflammation can be both a cause and a consequence of VTE, and c, current anti-coagulation therapies are not well-equipped with the capacity to selectively inhibit inflammatory cells and pathways. Applying such inferences for selective pharmacological targeting of immune mediators in VTE and thereby for adoption of higher effective anti-thromboinflammatory strategies, either therapeutic or prophylactic, is henceforth to be considered as the line of research for future.

Matrix metalloproteinase inhibition attenuates right ventricular dysfunction and improves responses to dobutamine during acute pulmonary thromboembolism

Activated matrix metalloproteinases (MMPs) cause cardiomyocyte injury during acute pulmonary thromboembolism (APT). However, the functional consequences of this alteration are not known. We examined whether doxycycline (a MMP inhibitor) improves right ventricle function and the cardiac responses to dobutamine during APT. APT was induced with autologous blood clots (350 mg/kg) in anaesthetized male lambs pre-treated with doxycycline (Doxy, 10 mg/kg/day, intravenously) or saline. Non-embolized control lambs received doxycycline pre-treatment or saline. The responses to intravenous dobutamine (Dob, 1, 5, 10 μg/kg/min.) or saline infusions at 30 and 120 min. after APT induction were evaluated by echocardiography. APT increased mean pulmonary artery pressure and pulmonary vascular resistance index by ∼185%. Doxycycline partially prevented APT-induced pulmonary hypertension (P < 0.05). RV diameter increased in the APT group (from 10.7 ± 0.8 to 18.3 ± 1.6 mm, P < 0.05), but not in the Doxy+APT group (from 13.3 ± 0.9 to 14.4 ± 1.0 mm, P > 0.05). RV dysfunction on stress echocardiography was observed in embolized lambs (APT+Dob group) but not in embolized animals pre-treated with doxycycline (Doxy+APT+Dob). APT increased MMP-9 activity, oxidative stress and gelatinolytic activity in the RV. Although doxycycline had no effects on RV MMP-9 activity, it prevented the increases in RV oxidative stress and gelatinolytic activity (P < 0.05). APT increased serum cardiac troponin I concentrations (P < 0.05), doxycycline partially prevented this alteration (P < 0.05). We found evidence to support that doxycycline prevents RV dysfunction and improves the cardiac responses to dobutamine during APT.

Limited value of novel pulmonary embolism biomarkers in patients with coronary atherosclerosis

BACKGROUND

Recent research supports the efficacy of various plasma biomarkers in diagnosing pulmonary embolism (PE) including E-selectin, MMP-9, MPO, sVCAM-1, sICAM-1, adiponectin, hs-CRP and tPAI-1.

OBJECTIVE

We hypothesized that these biomarkers, which are affected in both venous and arterial thromboembolic diseases, have a limited potential of diagnosing PE in patients with concomitant coronary atherosclerosis, as assessed from a low-dose CT scan of the thorax, compared to patients without atherosclerosis.

METHODS

Consecutive patients suspected of PE were referred. All patients had a ventilation/perfusion single photon emission tomography (V/Q-SPECT), low-dose pulmonary CT, pulmonary multidetector computer tomography angiography, blood samples and ECG-gated cardiac CT performed the same day.

RESULTS

A total of 69 patients were included, of which 28 (41%) had PE. In patients without coronary calcium, MMP-9 and tPAI-1 were significantly elevated (P<0·042 and P<0·049) in patients diagnosed with PE. From the receiver operating curves, we chose a cut-off value for MMP-9 at 164·4 ng l(-1) , which yielded sensitivity, specificity, positive and negative predictive values of 63%, 78%, 71% and 70%, respectively. With a chosen cut-off value for tPAI-1 at 56·3 ng l(-1) , the sensitivity, specificity, positive and negative predictive values were 88%, 89%, 88% and 89%, respectively. In patients with coronary calcium, none of the biomarkers could discriminate between PE and no PE.

CONCLUSION

Plasma levels of tPAI-1 and MMP-9 are potentially useful in patients suspected of PE, however, not in the presence of the coronary atherosclerosis.

Right ventricular heart failure from pulmonary embolism: key distinctions from chronic pulmonary hypertension

BACKGROUND

The right ventricle normally operates as a low pressure, high-flow pump connected to a high-capacitance pulmonary vascular circuit. Morbidity and mortality in humans with pulmonary hypertension (PH) from any cause is increased in the presence of right ventricular (RV) dysfunction, but the differences in pathology of RV dysfunction in chronic versus acute occlusive PH are not widely recognized.

METHODS AND RESULTS

Chronic PH that develops over weeks to months leads to RV concentric hypertrophy without inflammation that may progress slowly to RV failure. In contrast, pulmonary embolism (PE) results in an abrupt vascular occlusion leading to increased pulmonary artery pressure within minutes to hours that causes immediate deformation of the RV. RV injury is secondary to mechanical stretch, shear force, and ischemia that together provoke a cytokine and chemokine-mediated inflammatory phenotype that amplifies injury.

CONCLUSIONS

This review will briefly describe causes of pulmonary embolism and chronic PH, models of experimental study, and pulmonary vascular changes, and will focus on mechanisms of right ventricular dysfunction, contrasting mechanisms of RV adaptation and injury in these 2 settings.