In-hospital and readmission outcomes of patients with cancer admitted for pulmonary embolism treated with or without catheter-based therapy

BACKGROUND

Cancer patients are at risk of pulmonary embolism (PE). Catheter-based therapies (CBT) are novel reperfusion options for PE though data in patients with cancer is lacking.

STUDY DESIGN AND METHODS

Patients with intermediate- or high-risk PE were identified using the National Readmission Database (NRD) from 2017 to 2020. Primary outcome were in-hospital death and 90-day readmission. Secondary outcomes were in-hospital bleeding, 90-day readmission for venous thromboembolism (VTE)-related or right heart failure-related reasons and bleeding. Propensity scores were estimated using logistic regression and inverse-probability treatment weighting (IPTW) was utilized to compare outcomes between CBT and no CBT as well as CBT versus systemic thrombolysis.

RESULTS

A total of 7785 patients were included (2511 with high-risk PE) of whom 1045 (13.4%) were managed with CBT. After IPTW, CBT was associated with lower rates of index hospitalization death (OR 0.89, 95% CI 0.83-0.96) and 90-day readmission (HR 0.75, 95% CI 0.69-0.81) but higher rates of in-hospital bleeding (OR 1.11, 95% CI 1.03-1.20) which was predominantly post-procedural bleeding. CBT was associated with lower risk of major bleeding (20.8% vs 24.8%; OR 0.80, 95% CI 0.68-0.94) compared with systemic thrombolysis.

INTERPRETATION

Among patients with cancer with intermediate or high-risk PE, CBT was associated with lower in-hospital death and 90-day readmission. CBT was also associated with decreased risk of index hospitalization major bleeding compared with systemic thrombolysis. Prospective, randomized trials with inclusion of patients with cancer are needed to confirm these findings.

Low absolute risk of thrombotic and cardiovascular events in outpatient pregnant women with COVID-19

INTRODUCTION

Pregnancy may contribute to an excess risk of thrombotic or cardiovascular events. COVID-19 increases the risk of these events, although the risk is relatively limited among outpatients. We sought to determine whether outpatient pregnant women with COVID-19 are at a high risk for cardiovascular or thrombotic events.

MATERIALS & METHODS

We analyzed pregnant outpatients with COVID-19 from the multicenter CORONA-VTE-Network registry. The main study outcomes were a composite of adjudicated venous or arterial thrombotic events, and a composite of adjudicated cardiovascular events. Events were assessed 90 days after the COVID-19 diagnosis and reported for non-pregnant women ≤45 years, and for men ≤45 years, as points of reference.

RESULTS

Among 6585 outpatients, 169 were pregnant at diagnosis. By 90-day follow-up, two pregnant women during the third trimester had lower extremity venous thrombosis, one deep and one superficial vein thrombosis. The cumulative incidence of thrombotic events was 1.20 % (95 % confidence interval [CI]: 0.0 to 2.84 %). Respective rates were 0.47 % (95 % CI: 0.14 % to 0.79 %) among non-pregnant women, and 0.49 % (95 % CI: 0.06 % to 0.91 %) among men ≤45 years. No non-thrombotic cardiovascular events occurred in pregnant women. The rates of cardiovascular events were 0.53 % (95 % CI: 0.18 to 0.87) among non-pregnant women, and 0.68 % (95 % CI: 0.18 to 1.18) in men aged ≤45 years.

CONCLUSIONS

Thrombotic and cardiovascular events are rare among outpatients with COVID-19. Although a higher event rate among outpatient pregnant women cannot be excluded, the absolute event rates are low and do not warrant population-wide cardiovascular interventions to optimize outcomes.

Catheter-based therapy for high-risk or intermediate-risk pulmonary embolism: death and re-hospitalization

BACKGROUND AND AIMS

Catheter-based therapies (CBTs) have been developed as a treatment option in patients with pulmonary embolism (PE). There remains a paucity of data to inform decision-making in patients with intermediate-risk or high-risk PE. The aim of this study was to characterize in-hospital and readmission outcomes in patients with intermediate-risk or high-risk PE treated with vs. without CBT in a large retrospective registry.

METHODS

Patients hospitalized with intermediate-risk or high-risk PE were identified using the 2017-20 National Readmission Database. In-hospital outcomes included death and bleeding and 30- and 90-day readmission outcomes including all-cause, venous thromboembolism (VTE)-related and bleeding-related readmissions. Inverse probability of treatment weighting (IPTW) was utilized to compare outcomes between CBT and no CBT.

RESULTS

A total of 14 903 [2076 (13.9%) with CBT] and 42 829 [8824 (20.6%) with CBT] patients with high-risk and intermediate-risk PE were included, respectively. Prior to IPTW, patients with CBT were younger and less likely to have cancer and cardiac arrest, receive systemic thrombolysis, or be on mechanical ventilation. In the IPTW logistic regression model, CBT was associated with lower odds of in-hospital death in high-risk [odds ratio (OR) 0.83, 95% confidence interval (CI) 0.80-0.87] and intermediate-risk PE (OR 0.76, 95% CI 0.70-0.83). Patients with high-risk PE treated with CBT were associated with lower risk of 90-day all-cause [hazard ratio (HR) 0.77, 95% CI 0.71-0.83] and VTE (HR 0.46, 95% CI 0.34-0.63) readmission. Patients with intermediate-risk PE treated with CBT were associated with lower risk of 90-day all-cause (HR 0.75, 95% CI 0.72-0.79) and VTE (HR 0.66, 95% CI 0.57-0.76) readmission.

CONCLUSIONS

Among patients with high-risk or intermediate-risk PE, CBT was associated with lower in-hospital death and 90-day readmission. Prospective, randomized trials are needed to confirm these findings.

Risk of malignant ventricular arrhythmias in patients with mildly to moderately reduced ejection fraction after permanent pacemaker implantation

BACKGROUND

Many patients with mildly to moderately reduced left ventricular ejection fraction (LVEF) who require permanent pacemaker (PPM) implantation do not have a concurrent indication for implantable cardioverter-defibrillator (ICD) therapy. However, the risk of ventricular tachycardia/ventricular fibrillation (VT/VF) in this population is unknown.

OBJECTIVE

The aim of this study was to describe the risk of VT/VF after PPM implantation in patients with mildly to moderately reduced LVEF.

METHODS

Retrospective analysis was performed of 243 patients with LVEF between 35% and 49% who underwent PPM placement and did not meet indications for an ICD. The primary end point was occurrence of sustained VT/VF. Competing risks regression was performed to calculate subhazard ratios for the primary end point.

RESULTS

Median follow-up was 27 months; 73% of patients were male, average age was 79 ± 10 years, average LVEF was 42% ± 4%, and 70% were New York Heart Association class II or above. Most PPMs were implanted for sick sinus syndrome (34%) or atrioventricular block (50%). Of 243 total patients, 11 (4.5%) met the primary end point of VT/VF. Multivessel coronary artery disease (CAD) was associated with significantly higher rates of VT/VF, with a subhazard ratio of 5.4 (95% CI, 1.5-20.1; P = .01). Of patients with multivessel CAD, 8 of 82 (9.8%) patients met the primary end point for an annualized risk of 4.3% per year.

CONCLUSION

Patients with mildly to moderately reduced LVEF and multivessel CAD undergoing PPM implantation are at increased risk for the development of malignant ventricular arrhythmias. Patients in this population may benefit from additional risk stratification for VT/VF and consideration for upfront ICD implantation.

Catheter-based therapy for intermediate or high-risk pulmonary embolism is associated with lower in-hospital mortality in patients with cancer: Insights from the National Inpatient Sample

BACKGROUND

Pulmonary embolism (PE) is a common complication among patients with cancer and is a significant contributor to morbidity and mortality. Catheter-based therapies (CBT), including catheter-directed thrombolysis (CDT) and mechanical thrombectomy, have been developed and are used in patients with intermediate or high-risk PE. However, there is a paucity of data on outcomes in patients with cancer as most clinical studies exclude this group of patients.

AIMS

To characterize outcomes of patients with cancer admitted with intermediate or high-risk PE treated with CBT compared with no CBT.

METHODS

Patients with an admission diagnosis of intermediate or high-risk PE and a history of cancer from October 2015 to December 2018 were identified using the National Inpatient Sample. Outcomes of interest were in-hospital death or cardiac arrest (CA) and major bleeding. Inverse probability treatment weighting (IPTW) was utilized to compare outcomes between patients treated with and without CBT. Variables that remained unbalanced after IPTW were adjusted using multivariable logistic regression.

RESULTS

A total of 2084 unweighted admissions (10,420 weighted) for intermediate or high-risk PE and cancer were included, of which 136 (6.5%) were treated with CBT. After IPTW, CBT was associated with lower death or CA (aOR 0.54, 95% CI 0.46-0.64) but higher major bleeding (aOR 1.41, 95% CI 1.21-1.65). After stratifying by PE risk type, patients treated with CBT had lower risk of death or CA in both intermediate (aOR 0.52, 95% CI 0.36-0.75) and high-risk PE (aOR 0.48, 95% CI 0.33-0.53). However, patients with CBT were associated with increased risk of major bleeding in intermediate-risk PE (aOR 2.12, 95% CI 1.67-2.69) but not in those with high-risk PE (aOR 0.84, 95% CI 0.66-1.07).

CONCLUSIONS

Among patients with cancer hospitalized with intermediate or high-risk PE, treatment with CBT was associated with lower risk of in-hospital death or CA but higher risk of bleeding. Prospective studies and inclusion of patients with cancer in randomized trials are warranted to confirm our findings.

In-Hospital and readmission outcomes of patients with myeloproliferative neoplasms and atrial fibrillation: insights from the National Readmissions Database

INTRODUCTION

Patients with myeloproliferative neoplasms (MPNs) and atrial fibrillation (AF) are at increased risk of thrombosis and bleeding. However, the risk of thrombosis and bleeding in patients with AF and MPN compared with the general population with AF is unclear. Additionally, traditional risk scores (CHA2DS2-VASC and HAS-BLED) for risk/benefit estimation of thromboprophylaxis in AF do not account for MPN status. Therefore, we aimed to investigate bleeding and thrombosis risk in patients with MPN hospitalized for AF.

METHODS

We utilized the National Readmission Database (NRD) to identify patients with AF with and without MPN. Primary bleeding and thrombosis outcomes were in-hospital or 30-day readmission for bleeding or thrombosis, respectively. We propensity score (PS) matched patients with and without MPN. Risk of primary outcomes in MPN was assessed in PS matched cohort using logistic regression. Receiver operating characteristic (ROC) curve used to evaluate predictive ability of CHA2DS2-VASC and HAS-BLED of primary thrombosis and bleeding outcomes, respectively.

RESULTS

24,185 patients without MPN were matched with 1,617 patients with MPN and variables were balanced between groups. Patients with MPN were at increased risk of meeting the thrombosis (OR 1.98, 95% CI 1.23-3.21) but not bleeding (OR 0.87, 95% CI 0.63-1.19) primary outcomes. In MPN, CHA2DS2-VASC predicted thrombosis (C-statistic 0.66, 95% CI 0.54-0.78) but HAS-BLED was a poor predictor of bleeding (C-statistic 0.55, 95% CI 0.46-0.64).

CONCLUSION

In patients with AF, MPN was associated with increased risk of bleeding and thrombosis. HAS-BLED scores did not accurately predict bleeding in MPN. Further investigation is needed to refine risk scores in MPN.

In-Hospital and readmission outcomes of patients with myeloproliferative neoplasms and heart failure: Insights from the National Readmissions Database

Background

Myeloproliferative neoplasms (MPNs) are chronic leukemias associated with increased risk of cardiovascular (CV) events. Prior studies suggest patients with MPN are at increased risk of HF. Additionally, pre-clinical murine models harboring the JAK2 mutation, the most common driver mutation in MPNs, have shown accelerated adverse cardiac remodeling in myocardial infarction and pressure overload HF models. However, clinical outcomes, including in-hospital and readmission outcomes, of patients with MPN admitted for HF have not been well characterized.

Methods

Patients hospitalized for HF with and without MPN were identified using the 2017 and 2018 National Readmission Database. Propensity score matching (PSM) was performed to match 1 MPN with 10 non-MPN controls. Outcomes were in-hospital death, 90-day CV-related, HF-related, and all-cause readmissions. Logistic regression and Cox proportional hazards regression models were used to estimate risk of in-hospital death and 90-day readmission outcomes, respectively.

Results

After PSM, 4,626 patients with MPN were matched with 46,260 without. Patients with MPN were associated with increased risk of in-hospital death (OR 1.17, 95% CI 1.00 - 1.35), 90-day CV-related (HR 1.10, 95% CI 1.02 - 1.18) and all-cause (HR 1.24, 95% CI 1.17 - 1.31) but not HF-related (HR 1.05, 95% CI 0.97 - 1.14) readmissions.

Conclusion

Among patients hospitalized for HF, MPN was associated with increased risk of in-hospital death, and 90-day CV-related readmissions (driven primarily by thrombotic readmissions). Further investigation is needed in order to improve outcomes in patients with MPN and HF.

Acute myocardial infarction in von Willebrand disease: characteristics and outcomes

Background

Von Willebrand disease (VWD) is the most common inherited bleeding disorder. As treatments have improved prognosis of VWD, age-related diseases, including acute myocardial infarction (AMI), have become more prevalent. The treatment of AMI includes antithrombotic therapies, which increase the risk of bleeding. Current guidelines suggest weighing risks/benefits of antithrombotic therapy in patients with VWD. However, data to inform these discussions are lacking.

Objective

To characterize outcomes of patients with VWD after AMI.

Methods

We conducted a retrospective cohort study utilizing the National Readmissions Database of patients with and without VWD admitted with AMI in 2017 and 2018. Primary outcomes were 90-day any-cause, bleeding-related, and arterial thrombosis-related readmissions. Case-control matching was performed for age, sex (male or female), ST-elevation myocardial infarction, percutaneous coronary intervention, diabetes, and chronic kidney disease. Time-to-event analysis was performed after matching using Cox proportional hazards regression.

Results

A total of 136 patients with VWD were matched with 3400 controls without VWD. At 90 days, there were no differences in all-cause (10.7% vs 11.5%; P = 1.00), arterial thrombosis (1.9% vs 3.1%; P = .77), and bleeding (1.9% vs 0.4%; P = .083) readmission in patients with VWD. VWD was associated with increased risk of 90-day bleeding (hazard ratio [HR], 4.75; 95% CI, 1.05-21.66) but not all-cause (HR, 0.91; 95% CI, 0.50-1.67) or arterial thrombosis (HR, 0.54; 95% CI, 0.39-2.19) readmission.

Conclusion

Among patients admitted with AMI, VWD was associated with higher risk of 90-day readmission for bleeding but not any-cause and arterial thrombosis-related readmissions. Further studies are needed to balance bleeding and thrombotic risks post-AMI in patients with VWD.

Major cardiovascular events after COVID-19, event rates post-vaccination, antiviral or anti-inflammatory therapy, and temporal trends: Rationale and methodology of the CORONA-VTE-Network study

BACKGROUND

Coronavirus disease 2019 (COVID-19) is associated with excess risk of cardiovascular and thrombotic events in the early post-infection period and during convalescence. Despite the progress in our understanding of cardiovascular complications, uncertainty persists with respect to more recent event rates, temporal trends, association between vaccination status and outcomes, and findings within vulnerable subgroups such as older adults (aged 65 years or older), or those undergoing hemodialysis. Sex-informed findings, including results among pregnant and breastfeeding women, as well as adjusted comparisons between male and female adults are similarly understudied.

METHODS

Adult patients, aged ≥18 years, with polymerase chain reaction-confirmed COVID-19 who received inpatient or outpatient care at the participating centers of the registry are eligible for inclusion. A total of 10,000 patients have been included in this multicenter study, with Brigham and Women's Hospital (Boston, MA) serving as the coordinating center. Other sites include Beth Israel Deaconess Medical Center, Anne Arundel Medical Center, University of Virginia Medical Center, University of Colorado Health System, and Thomas Jefferson University Health System. Data elements will be ascertained manually for accuracy. The two main outcomes are 1) a composite of venous or arterial thrombotic events, and 2) a composite of major cardiovascular events, defined as venous or arterial thrombosis, myocarditis or heart failure with inpatient treatment, new atrial fibrillation/flutter, or cardiovascular death. Clinical outcomes are adjudicated by independent physicians. Vaccination status and time of inclusion in the study will be ascertained for subgroup-specific analyses. Outcomes are pre-specified to be reported separately for hospitalized patients versus those who were initially receiving outpatient care. Outcomes will be reported at 30-day and 90-day follow-up. Data cleaning at the sites and the data coordinating center and outcomes adjudication process are in-progress.

CONCLUSIONS

The CORONA-VTE-Network study will share contemporary information related to rates of cardiovascular and thrombotic events in patients with COVID-19 overall, as well as within key subgroups, including by time of inclusion, vaccination status, patients undergoing hemodialysis, the elderly, and sex-informed analyses such as comparison of women and men, or among pregnant and breastfeeding women.

Outcomes of Patients With Myeloproliferative Neoplasms Admitted With Myocardial Infarction: Insights From National Inpatient Sample

Background

Myeloproliferative neoplasms (MPNs) are hematopoietic stem cell neoplasms with a high risk of thrombosis, including acute myocardial infarction (AMI). However, outcomes after AMI have not been thoroughly characterized.

Objectives

The purpose of this study was to characterize outcomes after AMI in patients with MPNs compared with patients without MPNs.

Methods

Patients with a primary admission of AMI from January 2006 to December 2018 were identified using the National Inpatient Sample. Outcomes of interest included in-hospital death or cardiac arrest (CA) and major bleeding. Propensity score weighting was used to compare outcomes between MPN and non-MPN groups.

Results

A total of 1,644,304 unweighted admissions for AMI were included; of these admissions, 5,374 (0.3%) were patients with MPNs. After propensity score weighting, patients with MPNs had a lower risk of in-hospital death or CA (OR: 0.83; 95% CI: 0.82-0.84) but a higher risk of major bleeding (OR: 1.29; 95% CI: 1.28-1.30) compared with non-MPN patients. There was a decreasing temporal rate of in-hospital death or CA and bleeding in patients without MPNs (Ptrend < 0.001 for both). However, there was an increasing temporal rate of in-hospital death or CA (Ptrend < 0.001) and a stable rate of major bleeding (Ptrend = 0.48) in patients with MPNs.

Conclusions

Among patients hospitalized with AMI, patients with MPNs have a lower risk of in-hospital death or CA compared with patients without MPNs, although they have a higher risk of bleeding. More investigation is needed in order to improve post-AMI bleeding outcomes in patients with MPN.

Interventional Cardio-Oncology: Unique Challenges and Considerations in a High-Risk Population

OPINION STATEMENT

Patients with cancer are at risk of developing cardiovascular disease (CVD) including atherosclerotic heart disease (AHD), valvular heart disease (VHD), and atrial fibrillation (AF). Advances in percutaneous catheter-based treatments, including percutaneous coronary intervention (PCI) for AHD, percutaneous valve replacement or repair for VHD, and ablation and left atrial appendage occlusion devices (LAAODs) for AF, have provided patients with CVD significant benefit in the recent decades. However, trials and registries investigating outcomes of these procedures often exclude patients with cancer. As a result, patients with cancer are less likely to undergo these therapies despite their benefits. Despite the inclusion of cancer patients in randomized clinical trial data, studies suggest that cancer patients derive similar benefits of percutaneous therapies for CVD compared with patients without cancer. Therefore, percutaneous interventions for CVD should not be withheld in patients with cancer, as they may still benefit from these procedures.

Risk Factors for Death or Cardiovascular Events after Acute Coronary Syndrome in Patients with Myeloproliferative Neoplasms

Patients with myeloproliferative neoplasms (MPNs) are at increased risk of cardiovascular disease (CVD), including acute coronary syndrome (ACS). However, data on long-term outcomes of patients with MPN who have had ACS and risk factors for all-cause death or CV events post-ACS hospitalization are lacking. We conducted a single-center study of 41 consecutive patients with MPN with ACS hospitalization after MPN diagnosis. After a median follow-up of 80 months after ACS hospitalization, 31 (76%) experienced death or a CV event (myocardial infarction, ischemic stroke, or heart failure hospitalization). After multivariable Cox proportional hazards regression, index ACS within 12 months of MPN diagnosis (HR 3.84, 95% CI 1.44-10.19), WBC ≥ 20 K/µL (HR 9.10, 95% CI 2.71-30.52), JAK2 mutation (HR 3.71, 95% CI 1.22-11.22), and prior CVD (HR 2.60, 95% CI 1.12-6.08) were associated with increased death or CV events. Further studies are warranted to improve cardiovascular outcomes in this patient population.

Off-Target Effects of Cancer Therapy on Development of Therapy-Induced Arrhythmia: A Review

BACKGROUND

Advances in cancer therapeutics have improved overall survival and prognosis in this patient population; however, this has come at the expense of cardiotoxicity including arrhythmia.

SUMMARY

Cancer and its therapies are associated with cardiotoxicity via several mechanisms including inflammation, cardiomyopathy, and off-target effects. Among cancer therapies, anthracyclines and tyrosine kinase inhibitors (TKIs) are particularly known for their pro-arrhythmia effects. In addition to cardiomyopathy, anthracyclines may be pro-arrhythmogenic via reactive oxygen species (ROS) generation and altered calcium handling. TKIs may mediate their cardiotoxicity via inhibition of off-target tyrosine kinases. Ibrutinib-mediated inhibition of CSK may be responsible for the increased prevalence of atrial fibrillation. Further investigation is warranted to further elucidate the mechanisms behind arrhythmias in cancer therapies.

KEY MESSAGES

Arrhythmias are a common cardiotoxicity of cancer therapies. Cancer therapies may induce arrhythmias via off-target effects. Understanding the mechanisms underlying arrhythmogenesis associated with cancer therapies may help design cancer therapies that can avoid these toxicities.

Pulmonary hypertension is associated with poor cardiovascular and hematologic outcomes in patients with myeloproliferative neoplasms and cardiovascular disease

Cardiovascular events and hematologic progression to myelofibrosis or leukemia are leading causes of morbidity and mortality among patients with myeloproliferative neoplasms (MPN). Pulmonary hypertension (PH) is also associated with MPN and cardiovascular disease (CVD), though its prognostic significance in MPN is not well characterized. Our primary objective was to investigate the effect of PH, defined as right-ventricular systolic pressure (RVSP) ≥ 50 mmHg on echocardiogram or mean pulmonary artery pressure (mPAP) ≥ 20 on right heart catheterization, on cardiovascular and all-cause mortality and hematologic progression in patients with MPN and CVD (atrial fibrillation, heart failure hospitalization, and myocardial infarction after MPN diagnosis). Of the 197 patients included (86 ET, 80 PV, 31 PMF), 92 (47%) had PH and 98 (50%) were male. All-cause mortality (58 vs 37%, p = 0.004), cardiovascular death (35 vs 9%, p < 0.0001), and hematologic progression (23 vs 11%, p = 0.037) occurred more frequently in patients with PH. Multivariable competing-risk and proportional hazards regression showed that PH was associated with increased risk of all-cause death (adjusted hazard ratio [HR], 1.80, 95% CI 1.10-2.93), CV death (adjusted subdistribution HR 3.71, 95% CI 1.58-8.73), and hematologic progression (adjusted subdistribution HR 1.99, 95% CI 1.21-3.27).

Patients with myeloproliferative neoplasms and COVID-19 have increased rates of arterial thrombosis

Background

Both coronavirus disease‐2019 (COVID‐19) and myeloproliferative neoplasms (MPNs) are associated with systemic inflammation and risk of thrombosis. Risk of thrombosis in patients with COVID with and without MPNs has not been extensively studied.

Methods

Retrospective cohort study of 44 patients with MPNs and 1114 patients without MPNs positive for SARS‐COV‐2. Outcomes were arterial thrombosis (AT), venous thromboembolism (VTE), bleeding, and death. Time‐to‐event analysis was performed using competing risk regression model and Cox proportional hazards.

Results

AT occurred more frequently in patients with MPN (7% vs. 1%, p = 0.03). Rates of VTE (7% vs. 5%, p = 0.73), bleeding (7% vs. 2%, p = 0.06), and death (9% vs. 6%, p = 0.32) were similar. MPN patients were older and had more cardiovascular comorbidities. After time‐to‐event competing‐risk regression adjusting for age, MPN patients had higher risk of AT (subdivision hazards ratio 3.95, 95% CI 1.09–14.39) but not VTE, bleeding, or death.

Conclusions

Among patients with COVID‐19, MPN patients had higher risk of arterial thrombosis but not VTE, bleeding, and death compared with non‐MPN patients. Larger studies are needed to confirm our findings given the limited sample size.

Cardiovascular Disease in Myeloproliferative Neoplasms: JACC: CardioOncology State-of-the-Art Review

Myeloproliferative neoplasms are associated with increased risk for thrombotic complications. These conditions most commonly involve somatic mutations in genes that lead to constitutive activation of the Janus-associated kinase signaling pathway (eg, Janus kinase 2, calreticulin, myeloproliferative leukemia protein). Acquired gain-of-function mutations in these genes, particularly Janus kinase 2, can cause a spectrum of disorders, ranging from clonal hematopoiesis of indeterminate potential, a recently recognized age-related promoter of cardiovascular disease, to frank hematologic malignancy. Beyond thrombosis, patients with myeloproliferative neoplasms can develop other cardiovascular conditions, including heart failure and pulmonary hypertension. The authors review the pathophysiologic mechanisms of cardiovascular complications of myeloproliferative neoplasms, which involve inflammation, prothrombotic and profibrotic factors (including transforming growth factor-beta and lysyl oxidase), and abnormal function of circulating clones of mutated leukocytes and platelets from affected individuals. Anti-inflammatory therapies may provide cardiovascular benefit in patients with myeloproliferative neoplasms, a hypothesis that requires rigorous evaluation in clinical trials.

Common Pathophysiology in Cancer, Atrial Fibrillation, Atherosclerosis, and Thrombosis: JACC: CardioOncology State-of-the-Art Review

Cardiovascular disease and cancer are the 2 leading causes of death worldwide. Emerging evidence suggests common mechanisms between cancer and cardiovascular disease, including atrial fibrillation and atherosclerosis. With advances in cancer therapies, screening, and diagnostics, cancer-specific survival and outcomes have improved. This increase in survival has led to the coincidence of cardiovascular disease, including atrial fibrillation and atherosclerosis, as patients with cancer live longer. Additionally, cancer and cardiovascular disease share several risk factors and underlying pathophysiologic mechanisms, including inflammation, cancer-related factors including treatment effects, and alterations in platelet function. Patients with cancer are at increased risk for bleeding and thrombosis compared with the general population. Although optimal antithrombotic therapy, including agent choice and duration, has been extensively studied in the general population, this area remains understudied in patients with cancer despite their altered thrombotic and bleeding risk. Future investigation, including incorporation of cancer-specific characteristics to traditional thrombotic and bleeding risk scores, clinical trials in the cancer population, and the development of novel antithrombotic and anti-inflammatory strategies on the basis of shared pathophysiologic mechanisms, is warranted to improve outcomes in this patient population.

Dual antithrombotic therapy with dabigatran in patients with atrial fibrillation after percutaneous coronary intervention for ST-segment elevation myocardial infarction: a post hoc analysis of the randomised RE-DUAL PCI trial

BACKGROUND

Little is known about the optimal antithrombotic therapy in patients with atrial fibrillation undergoing PCI for ST-elevation myocardial infarction (STEMI).

AIMS

The aim of this study was to investigate the safety and efficacy of dabigatran dual therapy (110 or 150 mg twice daily, plus clopidogrel or ticagrelor) versus warfarin triple therapy in patients with atrial fibrillation and STEMI.

METHODS

In the RE-DUAL PCI trial, 305 patients with STEMI were randomised to dabigatran 110 mg (n=113 versus 106 warfarin) or 150 mg (n=86 versus 84 warfarin). The primary endpoint was the time to first major/clinically relevant non-major bleeding event (MBE/CRNMBE). The thrombotic endpoint was a composite of death, thromboembolic events, or unplanned revascularisation.

RESULTS

In STEMI patients, dabigatran 110 mg (HR 0.39, 95% CI: 0.20-0.74) and 150 mg (0.43, 0.21-0.89) dual therapy reduced the risk of MBE/CRNMBE versus warfarin triple therapy (p for interaction vs all other patients=0.31 and 0.16). The risk of thrombotic events for dabigatran 110 mg (HR 1.61, 95% CI: 0.85-3.08) and 150 mg (0.56, 0.20-1.51) had p interactions of 0.20 and 0.33, respectively. For net clinical benefit, the HRs were 0.74 (95% CI: 0.46-1.17) and 0.49 (0.27-0.91) for dabigatran 110 and 150 mg (p for interaction=0.80 and 0.12), respectively.

CONCLUSIONS

After PCI for STEMI, patients on dabigatran dual therapy had lower risks of bleeding events versus warfarin triple therapy with similar risks of thromboembolic events, supporting dabigatran dual therapy even in patients with high thrombotic risk.

Natural language processing for the assessment of cardiovascular disease comorbidities: The cardio-Canary comorbidity project

Objective: Accurate ascertainment of comorbidities is paramount in clinical research. While manual adjudication is labor‐intensive and expensive, the adoption of electronic health records enables computational analysis of free‐text documentation using natural language processing (NLP) tools.

Hypothesis: We sought to develop highly accurate NLP modules to assess for the presence of five key cardiovascular comorbidities in a large electronic health record system.

Methods: One‐thousand clinical notes were randomly selected from a cardiovascular registry at Mass General Brigham. Trained physicians manually adjudicated these notes for the following five diagnostic comorbidities: hypertension, dyslipidemia, diabetes, coronary artery disease, and stroke/transient ischemic attack. Using the open‐source Canary NLP system, five separate NLP modules were designed based on 800 “training‐set” notes and validated on 200 “test‐set” notes.

Results: Across the five NLP modules, the sentence‐level and note‐level sensitivity, specificity, and positive predictive value was always greater than 85% and was most often greater than 90%. Accuracy tended to be highest for conditions with greater diagnostic clarity (e.g. diabetes and hypertension) and slightly lower for conditions whose greater diagnostic challenges (e.g. myocardial infarction and embolic stroke) may lead to less definitive documentation.

Conclusion: We designed five open‐source and highly accurate NLP modules that can be used to assess for the presence of important cardiovascular comorbidities in free‐text health records. These modules have been placed in the public domain and can be used for clinical research, trial recruitment and population management at any institution as well as serve as the basis for further development of cardiovascular NLP tools.

Association of Thrombosis With Hypereosinophilic Syndrome in Patients With Genetic Alterations

IMPORTANCE

Hypereosinophilic syndromes (HESs) are a rare group of disorders that result in overproduction of eosinophils, leading to tissue damage. Thrombotic complications in HES and associated risk factors in this patient population have not been extensively studied.

OBJECTIVE

To investigate the rates of and risk factors associated with thrombotic events in patients with HES, including markers of clonal hematopoiesis as evidenced by molecular aberrations on next-generation sequencing.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study evaluated patients seen at Brigham and Women's Hospital and Harvard Medical School in Boston, Massachusetts, from January 1, 2015, to January 1, 2020. Patients who had hypereosinophilia with an absolute eosinophil count of 1500 cells/μL or greater on 2 separate occasions at least 1 month apart and who underwent genetic or molecular testing as part of their work-up were included. Patients with secondary eosinophilia were excluded.

MAIN OUTCOMES AND MEASURES

Symptomatic and asymptomatic arterial and venous thrombotic events after the diagnosis of HES and all-cause death.

RESULTS

A total of 71 patients (median age, 58 years [interquartile range (IQR), 43-67 years]; 36 women [51%]; 57 White patients [80%]) were included. Patients had a median follow-up time of 29 months (IQR, 19-49 months). Seventeen patients (24%) had 1 or more thrombotic events, including 11 venous thromboembolic events and 11 arterial thrombotic events (8 patients had ≥1 event and 3 patients had recurrent events). Patients with 1 or more thrombotic events had a higher median Eastern Cooperative Oncology Group performance status (median, 1 [IQR, 1-2] vs 0 [IQR, 0-1]; P = .002), had more frequent cardiac involvement (7 of 17 events [41%] vs 6 of 54 events [11%]; P = .01), more frequently received treatment (17 of 17 events [100%] vs 40 of 54 events [74%]; P = .02), and had more molecular aberrations on next-generation sequencing (12 of 17 [71%] vs 12 of 54 [26%]; P = .003) vs patients without thrombosis. After multivariable analysis, the presence of molecular aberration was associated with increased odds of thrombosis (adjusted odds ratio, 5.4; 95% CI, 1.1-27.7). Death occurred more frequently in patients with thrombotic events compared with those without (6 of 17 [35%] vs 2 of 54 [4%]; P = .002) and in patients with molecular aberrations compared with those without (6 of 24 [25%] vs 1 of 40 [3%]; P = .009), although only thrombotic events were significantly associated with increased odds of death after multivariable analysis.

CONCLUSIONS AND RELEVANCE

In this cohort study, thrombosis was common in patients with HES and was significantly associated with increased risk of death.

Cancer and thrombosis: new insights to an old problem

Venous thromboembolism (VTE) is a common complication in patients with cancer and portends a poor prognosis. Our understanding of the underlying pathophysiology of VTE in cancer has advanced since Trousseau first described hypercoagulability in patients with malignancy and Virchow described his famous triad of thrombosis formation. Malignancy itself induces a thrombophilic state by increasing the risk of venous stasis, endothelial injury and an imbalance of pro and anti-thrombotic factors leading to a hypercoaguable state. Additional insults to this thrombotic balance are introduced by patient-specific, treatment related and tumor-specific factors. The importance of understanding the factors associated with increased thrombosis in cancer is paramount in order to adequately identify patients who will benefit from thromboprophylaxis.

Lysyl oxidase inhibition in primary myelofibrosis: A renewed strategy

Primary myelofibrosis (PMF) is a type of myeloproliferative neoplasm (MPN) that portends a poor prognosis and has limited options for treatment. PMF is often driven by clonal mutations in one of three genes that regulate the JAK-STAT signaling pathway, leading to hyperactivation of this signaling pathway and over-proliferation of megakaryocytes (MKs) and their precursors. PMF presents with debilitating symptoms such as splenomegaly and weight loss. The few available treatments for PMF include a JAK2 inhibitor, ruxolitinib, which causes side effects and is not always effective. The extracellular matrix (ECM) and bone marrow (BM) microenvironment may play an important role in the pathogenesis of PMF. Lysyl oxidase (LOX), an enzyme that plays a key role in the ECM by facilitating the cross-linking of collagen and elastin fibers, has been shown to be upregulated in MKs of PMF mice and in PMF patients, suggesting its role in the progression of BM fibrosis. Recently, LOX has been identified as a potential novel therapeutic target for PMF and the development of new small molecule LOX inhibitors, PXS-LOX_1 and PXS-LOX_2, has shown some promise in slowing the progression of PMF in pre-clinical studies. Given that these inhibitors displayed an ability to target the dysregulation of the ECM via LOX inhibition, they show promise as therapeutic agents for an underappreciated aspect of PMF.

Registry of Arterial and Venous Thromboembolic Complications in Patients With COVID-19

Background

Cardiovascular complications, including myocardial infarction, ischemic stroke, and pulmonary embolism, represent an important source of adverse outcomes in coronavirus disease-2019 (COVID-19).

Objectives

To assess the frequency of arterial and venous thromboembolic disease, risk factors, prevention and management patterns, and outcomes in patients with COVID-19, the authors designed a multicenter, observational cohort study.

Methods

We analyzed a retrospective cohort of 1,114 patients with COVID-19 diagnosed through our Mass General Brigham integrated health network. The total cohort was analyzed by site of care: intensive care (n = 170); hospitalized nonintensive care (n = 229); and outpatient (n = 715). The primary study outcome was a composite of adjudicated major arterial or venous thromboembolism.

Results

Patients with COVID-19 were 22.3% Hispanic/Latinx and 44.2% non-White. Cardiovascular risk factors of hypertension (35.8%), hyperlipidemia (28.6%), and diabetes (18.0%) were common. Prophylactic anticoagulation was prescribed in 89.4% of patients with COVID-19 in the intensive care cohort and 84.7% of those in the hospitalized nonintensive care setting. Frequencies of major arterial or venous thromboembolism, major cardiovascular adverse events, and symptomatic venous thromboembolism were highest in the intensive care cohort (35.3%, 45.9%, and 27.0 %, respectively) followed by the hospitalized nonintensive care cohort (2.6%, 6.1%, and 2.2%, respectively) and the outpatient cohort (0% for all).

Conclusions

Major arterial or venous thromboembolism, major adverse cardiovascular events, and symptomatic venous thromboembolism occurred with high frequency in patients with COVID-19, especially in the intensive care setting, despite a high utilization rate of thromboprophylaxis.

Study of lipoprotein(a) and its impact on atherosclerotic cardiovascular disease: Design and rationale of the Mass General Brigham Lp(a) Registry

Lipoprotein(a) [Lp(a)] is independently associated with atherosclerotic cardiovascular disease and calcific aortic valve stenosis. Elevated Lp(a) affects approximately one in five individuals and meaningfully contributes to the residual cardiovascular risk in individuals with otherwise well-controlled risk factors. With targeted therapies in the therapeutic pipeline, there is a need to further characterize the clinical phenotypes and outcomes of individuals with elevated levels of this unique biomarker. The Mass General Brigham Lp(a) Registry will be built from the longitudinal electronic health record of two large academic medical centers in Boston, Massachusetts, to develop a detailed cohort of patients who have had their Lp(a) measured. In combination with structured data sources, clinical documentation will be analyzed using natural language processing techniques to accurately characterize baseline characteristics. Important outcome measures including all-cause mortality, cardiovascular mortality, and cardiovascular events will be available for analysis. Approximately 30 000 patients who have had their Lp(a) tested within the Mass General Brigham system from January 2000 to July 2019 will be included in the registry. This large Lp(a) cohort will provide meaningful observational data regarding the differential risk associated with Lp(a) values and cardiovascular disease. With a new frontier of targeted Lp(a) therapies on the horizon, the Mass General Brigham Lp(a) Registry will help provide a deeper understanding of Lp(a)'s role in long term cardiovascular outcomes.

What Looks Like a Clot But Is Not a Clot?: Cardiac Leiomyosarcoma Mimicking Pulmonary Embolism

Primary cardiac tumors in the right ventricular outflow tract are often misdiagnosed as pulmonary embolism due to rarity and inadequate imaging characterization. Multimodality imaging offers advantages and facilitates subsequent diagnostics and management. We present a case of a woman with suspected submassive pulmonary embolism who was found to have pleomorphic leiomyosarcoma. (Level of Difficulty: Intermediate.).

Pregnancy outcomes, risk factors, and cell count trends in pregnant women with essential thrombocythemia

Pregnancy in essential thrombocythemia (ET) is associated with increased risk of obstetric complications. We retrospectively evaluated risk factors in 121 pregnancies in 52 ET women seen at 3 affiliate hospitals. Univariable and multivariable analyses were performed at the α = 0.10 level. Cell counts were characterized throughout pregnancy and correlated with outcomes using logistic modeling. The overall live birth rate was 69 %. 48.7 % of all women experienced a pregnancy complication, the most common being spontaneous abortion, which occurred in 26 % of all pregnancies. Maternal thrombosis and hemorrhage rates were 2.5 % and 5.8 %. On multivariable analysis, aspirin use (OR 0.29, p = 0.014, 90 % CI 0.118-0.658) and history of prior pregnancy loss (OR 3.86, p = 0.011, CI 1.49-9.15) were associated with decreased and increased pregnancy complications, respectively. A Markov model was used to analyze the probability of a future pregnancy complication based on initial pregnancy outcome. An ET woman who suffers a pregnancy complication has a 0.594 probability of a subsequent pregnancy complication, compared to a 0.367 probability if she didn't suffer a complication. However, despite this elevated risk, overall prognosis is good, with a >50 % probability of a successful pregnancy by the third attempt. Platelet counts decreased by 43 % in ET during pregnancy, with nadir at delivery and prompt recovery in the postpartum period. Women with larger declines in gestational platelet counts were less likely to suffer complications (p = 0.083). Our study provides important guidance to physicians treating ET women during pregnancy, including counseling information regarding risk assessment and expected trajectory of platelet levels.

Platelet Dysfunction and Thrombosis in JAK2V617F-Mutated Primary Myelofibrotic Mice

OBJECTIVE

The risk of thrombosis in myeloproliferative neoplasms, such as primary myelofibrosis varies depending on the type of key driving mutation (JAK2 [janus kinase 2], CALR [calreticulin], and MPL [myeloproliferative leukemia protein or thrombopoietin receptor]) and the accompanying mutations in other genes. In the current study, we sought to examine the propensity for thrombosis, as well as platelet activation properties in a mouse model of primary myelofibrosis induced by JAK2^V617F (janus kinase 2 with valine to phenylalanine substitution on codon 617) mutation. Approach and Results: Vav1-hJAK2^V617F transgenic mice show hallmarks of primary myelofibrosis, including significant megakaryocytosis and bone marrow fibrosis, with a moderate increase in red blood cells and platelet number. This mouse model was used to study responses to 2 models of vascular injury and to investigate platelet properties. Platelets derived from the mutated mice have reduced aggregation in response to collagen, reduced thrombus formation and thrombus size, as demonstrated using laser-induced or FeCl₃-induced vascular injury models, and increased bleeding time. Strikingly, the mutated platelets had a significantly reduced number of dense granules, which could explain impaired ADP secretion upon platelet activation, and a diminished second wave of activation.

CONCLUSIONS

Together, our study highlights for the first time the influence of a hyperactive JAK2 on platelet activation-induced ADP secretion and dense granule homeostasis, with consequent effects on platelet activation properties.

Impact of Tumor Genomic Mutations on Thrombotic Risk in Cancer Patients

Venous thromboembolism (VTE) is common in patients with cancer and is an important contributor to morbidity and mortality in these patients. Early thromboprophylaxis initiated only in those cancer patients at highest risk for VTE would be optimal. Risk stratification scores incorporating tumor location, laboratory values and patient characteristics have attempted to identify those patients most likely to benefit from thromboprophylaxis but even well-validated scores are not able to reliably distinguish the highest-risk patients. Recognizing that tumor genetics affect the biology and behavior of malignancies, recent studies have explored the impact of specific molecular aberrations on the rate of VTE in cancer patients. The presence of certain molecular aberrations in a variety of different cancers, including lung, colon, brain and hematologic tumors, have been associated with an increased risk of VTE and arterial thrombotic events. This review examines the findings of these studies and discusses the implications of these findings on decisions relating to thromboprophylaxis use in the clinical setting. Ultimately, the integration of tumor molecular genomic information into clinical VTE risk stratification scores in cancer patients may prove to be a major advancement in the prevention of cancer-associated thrombosis.

Impact of ALK Rearrangement on Venous and Arterial Thrombotic Risk in NSCLC

INTRODUCTION

Clinical venous thromboembolism (VTE) risk prediction scores, such as the Khorana Risk Score, perform poorly in NSCLC, possibly because the tumor molecular subtype is omitted. Previous studies suggest a possible increased VTE risk in ALK-rearranged NSCLC, but data are conflicting.

METHODS

We performed a retrospective cohort study of patients with advanced-stage NSCLC diagnosed between 2009 and 2019. Multivariable, time-to-event analyses modeling the risk of first venous or arterial thrombosis in ALK and non-ALK NSCLC groups, controlling for covariates known to impact thrombosis risk (15 in VTE model and 17 in arterial thrombosis model), were performed using Cox proportional hazards regression and competing-risks regression. Multivariable negative binomial regression modeled the total VTE rate.

RESULTS

A total of 422 patients with ALK-rearranged and 385 patients with non-ALK-rearranged NSCLC were included. Patients with an ALK rearrangement were younger, had better performance status, and had lower rates of most thrombotic risk factors but had significantly higher rates of initial VTE (42.7% versus 28.6%, p < 0.0001), recurrent VTE (13.5% versus 3.1%, p < 0.0001), and similar rates of arterial thrombosis (5.0% versus 4.4%, p = 0.71) compared with non-ALK NSCLC. VTE risk attributable to ALK was significant (Cox model: hazard ratio 3.70, [95% confidence interval [CI]: 2.51-5.44, p < 0.001], competing risks: subhazard ratio 3.91 [95% CI: 2.55-5.99, p < 0.001]). Negative binomial modeling revealed higher VTE rates in patients with an ALK rearrangement (incidence rate ratio 2.47 [95% CI: 1.72-3.55, p < 0.001]). The OR for recurrent VTE was 4.85 (95% CI: 2.60-9.52, p < 0.001). Arterial thrombosis risk attributable to ALK was significant (Cox model: hazard ratio 3.15 [95% CI: 1.18-8.37, p = 0.021], competing risks: subhazard ratio 2.80 [95% CI: 1.06-7.43, p = 0.038]).

CONCLUSIONS

In time-to-event analyses controlling for thrombosis risk factors, the ALK rearrangement conferred a fourfold increase in VTE risk and a threefold increase in arterial thrombosis risk in NSCLC. These patients may benefit from pharmacologic thromboprophylaxis.

Novel lysyl oxidase inhibitors attenuate hallmarks of primary myelofibrosis in mice

Primary myelofibrosis (PMF) is a chronic myeloproliferative neoplasm (MPN) that usually portends a poor prognosis with limited therapeutic options available. Currently, only allogeneic stem cell transplantation is curative in those who are candidates, while administration of the JAK1/2 inhibitor ruxolitinib carries a risk of worsening cytopenia. The limited therapeutic options available highlight the need for the development of novel treatments for PMF. Lysyl oxidase (LOX), an enzyme vital for collagen cross-linking and extracellular matrix stiffening, has been found to be upregulated in PMF. Herein, we evaluate two novel LOX inhibitors, PXS-LOX_1 and PXS-LOX_2, in two animal models of PMF (GATA1low and JAK2V617F-mutated mice). Specifically, PXS-LOX_1 or vehicle was given to 15- to 16-week-old GATA1low mice via intraperitoneal injection at a dose of 15 mg/kg four times a week for 9 weeks. PXS-LOX_1 was found to significantly decrease the bone marrow fibrotic burden and megakaryocyte number compared to vehicle in both male and female GATA1low mice. Given these results, PXS-LOX_1 was then tested in 15- to 17-week-old JAK2V617F-mutated mice at a dose of 30 mg/kg four times a week for 8 weeks. Again, we observed a significant decrease in bone marrow fibrotic burden. PXS-LOX_2, a LOX inhibitor with improved oral bioavailability, was next evaluated in 15- to 17-week-old JAK2V617F-mutated mice at a dose of 5 mg/kg p.o. four times a week for 8 weeks. This inhibitor also resulted in a significant decrease in bone marrow fibrosis, albeit with a more pronounced amelioration in female mice. Taking these results together, PXS-LOX_1 and PXS-LOX_2 appear to be promising new candidates for the treatment of fibrosis in PMF.

Emerging Factors Implicated in Fibrotic Organ-Associated Thrombosis: The Case of Two Organs

Thrombosis is at the heart of cardiovascular complications observed in specific diseases. A heightened thrombosis risk above that in general population in diseases such as myelofibrosis and chronic kidney disease implicates disease-specific mediators of thrombosis. This relative lack of information regarding the mechanisms of thrombosis in specific organ pathologies hitherto has remained limited. Evolving literature implicates some soluble factors in the blood of patients with discrete disorders, inflicting fundamental changes in the components of thrombosis. In this era of precision medicine, integrating these disease-specific factors in a comprehensive thrombotic risk assessment of patients is imperative in guiding therapeutic decisions. A complex network of mechanisms regulates each organ pathology and resultant thrombotic phenotypes. This review surveys different effectors of thrombogenicity associated with two pathologically fibrotic organs used as model systems, the bone marrow and kidney, as well as focuses attention to a common inducer of fibrosis and thrombosis, lysyl oxidase.

The role of extracellular matrix stiffness in megakaryocyte and platelet development and function

The extracellular matrix (ECM) is a key acellular structure in constant remodeling to provide tissue cohesion and rigidity. Deregulation of the balance between matrix deposition, degradation, and crosslinking results in fibrosis. Bone marrow fibrosis (BMF) is associated with several malignant and nonmalignant pathologies severely affecting blood cell production. BMF results from abnormal deposition of collagen fibers and enhanced lysyl oxidase-mediated ECM crosslinking within the marrow, thereby increasing marrow stiffness. Bone marrow stiffness has been recently recognized as an important regulator of blood cell development, notably by modifying the fate and differentiation process of hematopoietic or mesenchymal stem cells. This review surveys the different components of the ECM and their influence on stem cell development, with a focus on the impact of the ECM composition and stiffness on the megakaryocytic lineage in health and disease. Megakaryocyte maturation and the biogenesis of their progeny, the platelets, are thought to respond to environmental mechanical forces through a number of mechanosensors, including integrins and mechanosensitive ion channels, reviewed here.

The role of the extracellular matrix in primary myelofibrosis

Primary myelofibrosis (PMF) is a myeloproliferative neoplasm that arises from clonal proliferation of hematopoietic stem cells and leads to progressive bone marrow (BM) fibrosis. While cellular mutations involved in the development of PMF have been heavily investigated, noteworthy is the important role the extracellular matrix (ECM) plays in the progression of BM fibrosis. This review surveys ECM proteins contributors of PMF, and highlights how better understanding of the control of the ECM within the BM niche may lead to combined therapeutic options in PMF.

Loss of prolyl carboxypeptidase in two-kidney, one-clip goldblatt hypertensive mice

It is well documented that angiotensin (Ang) II contributes to kidney disease progression. The protease prolyl carboxypeptidase (PRCP) is highly expressed in the kidney and may be renoprotective by degrading Ang II to Ang-(1-7). The aim of the study was to investigate whether renal PRCP protein expression and activity are altered in two-kidney, one-clip (2K1C) Goldblatt hypertensive mice. Left renal artery was constricted by using 0.12 mm silver clips. Blood pressure was measured using telemetry over the eleven weeks of study period and revealed an immediate increase in 2K1C animals during the first week of clip placement which was followed by a gradual decrease to baseline blood pressure. Similarly, urinary albumin excretion was significantly increased one week after 2K1C and returned to baseline levels during the following weeks. At 2 weeks and at the end of the study, renal pathologies were exacerbated in the 2K1C model as revealed by a significant increase in mesangial expansion and renal fibrosis. Renal PRCP expression and activity were significantly reduced in clipped kidneys. Immunofluorescence revealed the loss of renal tubular PRCP but not glomerular PRCP. In contrast, expression of prolyl endopeptidase, another enzyme capable of converting Ang II into Ang-(1-7), was not affected, while angiotensin converting enzyme was elevated in unclipped kidneys and renin was increased in clipped kidneys. Results suggest that PRCP is suppressed in 2K1C and that this downregulation may attenuate renoprotective effects via impaired Ang II degradation by PRCP.

Abstract 188: Loss of Renal Prolyl Carboxypeptidase in Mice With Chronic Kidney Disease

There are 26 million adults with chronic kidney disease (CKD) in the U.S. and the incidence continues to increase. It is well documented that the activation of the renin angiotensin system and the elevated formation of angiotensin (Ang) II both contribute to renal pathophysiology in CKD. Emerging evidence suggests that the Ang II degrading protease prolyl carboxypeptidase (PCP) is renoprotective. Thus, we investigated protein expression and activity of renal PCP using immunofluorescence, western blot and mass spectrometry in a mouse model of CKD. Renal injury in male C57Bl6 mice was caused by constriction of the left renal artery using silver clips (2K1C-method). Blood pressure measurements by radiotelemetry revealed a significant increase of 36.1 ± 3.9 mm Hg in 2K1C animals compared with control animals 1 week after clip placement (p<0.0001). Using immunofluorescence and confocal microscopy, PCP was localized in the Bowman’s capsule of the glomerulus and in proximal and distal renal tubules. Western blot analysis showed PCP was significantly reduced in clipped 2K1C kidneys compared to unclipped kidneys of the 2K1C mice or compared to control mice (clipped 0.04 ± 0.02 vs unclipped 0.58 ± 0.16 vs control 0.65 ± 0.18, p < 0.05). In addition, renal PCP enzyme activity was found to be markedly reduced in 2K1C kidneys as assessed by mass spectrometric based enzyme assays (clipped 37.1 ± 4.3 pmol Ang-(1-7)/h/μg vs unclipped 77.3 ± 12.3 pmol Ang-(1-7)/h/μg vs control 120.7 ± 14.7 pmol Ang-(1-7)/h/μg, p < 0.01). In contrast, protein expression of prolyl endopeptidase, another enzyme capable of converting Ang II into Ang-(1-7), was not affected. Notably, renal pathologies were exacerbated in the 2K1C model as revealed by a significant increase in mesangial expansion (clipped 34.6 ± 3.1 vs unclipped 52.1 ± 4.0 vs control 1.2 ± 2.1, p < 0.0001) and renal fibrosis (clipped 57.5 ± 0.9 vs unclipped 33.0 ± 0.7 vs control 3.3 ± 0.2, p < 0.0001). Results suggest that PCP is suppressed in chronic kidney injury and that this downregulation may attenuate renoprotective effects via impaired Ang II degradation by PCP. Therefore, Ang II processing by PCP may have clinical implications in patients with renal pathologies.

Identification of prolyl carboxypeptidase as an alternative enzyme for processing of renal angiotensin II using mass spectrometry

Angiotensin-converting enzyme 2 (ACE2) catalyzes conversion of ANG II to ANG-(1-7). The present study uses newly established proteomic approaches and genetic mouse models to examine the contribution of alternative renal peptidases to ACE2-independent formation of ANG-(1-7). In situ and in vitro mass spectrometric characterization showed that substrate concentration and pH control renal ANG II processing. At pH ≥6, ANG-(1-7) formation was significantly reduced in ACE2 knockout (KO) mice. However, at pH <6, formation of ANG-(1-7) in ACE2 KO mice was similar to that in wild-type (WT) mice, suggesting alternative peptidases for renal ANG II processing. Furthermore, the dual prolyl carboxypeptidase (PCP)-prolyl endopeptidase (PEP) inhibitor Z-prolyl-prolinal reduced ANG-(1-7) formation in ACE2 KO mice, while the ACE2 inhibitor MLN-4760 had no effect. Unlike the ACE2 KO mice, ANG-(1-7) formation from ANG II in PEP KO mice was not different from that in WT mice at any tested pH. However, at pH 5, this reaction was significantly reduced in kidneys and urine of PCP-depleted mice. In conclusion, results suggest that ACE2 metabolizes ANG II in the kidney at neutral and basic pH, while PCP catalyzes the same reaction at acidic pH. This is the first report demonstrating that renal ANG-(1-7) formation from ANG II is independent of ACE2. Elucidation of ACE2-independent ANG-(1-7) production pathways may have clinically important implications in patients with metabolic and renal disease.

Abstract 633: Lack of ACE2 Abolishes High Fat Diet-Induced Upregulation of Prolyl Carboxypeptidase

Emerging evidence suggests that activation of the proteases, Ang converting enzyme 2 (ACE2) and prolyl carboxypeptidase (PCP), are associated with metabolic pathologies. We hypothesized that global loss of ACE2 affects high fat diet induced renal expression of PCP. ACE2 knockout (ACE2KO) and wild type (WT) male mice were fed a 60% high fat (HF) or normal chow (NC) diet for 12 weeks. Using dual immunofluorescence microscopy and western blotting, we determined the expression pattern and abundance of ACE2 and PCP in kidney. PCP was co-localized with ACE2 in the Bowman’s capsule of the glomerulus. PCP was also localized along the apical membrane of proximal tubules along with ACE2. There was no evidence for protease co-localization in the tubules. ACE2 was absent in kidney from ACE2KO (immunofluorescence or western). PCP localization was unchanged in ACE2KO and the localization of both proteases did not change in response to HF diet. Protein intensity, normalized to ß-actin, showed no difference in PCP between untreated WT and KO (0.76±0.18 vs 0.57±0.07). PCP in HF WT was significantly elevated as compared to HF KO (0.94±0.02 vs 0.57±0.03, p≤0.05) while HF WT ACE2 levels remained unchanged as compared to untreated WT (0.90±0.24 vs 0.94±0.16). Results indicate loss of ACE2 negatively affects HF diet-induced PCP expression. Neither the absence of ACE2 nor HF diet changed the localization of PCP. These results suggest interactions between ACE2 and PCP in metabolic pathologies.

Urological complications after simultaneous pancreas-kidney transplantation

OBJECTIVE

We evaluated the incidence of urological complications after simultaneous renal and pancreatic transplantation.

PATIENTS AND METHODS

We retrospectively reviewed urological complications following 107 simultaneous kidney-pancreas transplantations performed at our institution between March 1995 and June 2008. The 46 women and 61 men were of mean age 37.8 years (range, 25-66). The mean duration of diabetes mellitus was 23.0 years (range, 9-48) and the mean duration of dialysis was 19.9 months (range, 0-70). The exocrine pancreatic secretions were drained to bladder in 58 cases, or enterically in 49 patients. The mean length of follow-up was 51.7 months.

RESULTS

The most frequent urological complication was urinary tract infection, reported in 63.8% of patients: 42 bladder-drained and 25 enteric-drained (P = .011). Hematuria occurred in 13 patients (12.5%): 12 bladder-drained and 1 enteric-drained (P = .002). Five bladder-drained patients developed bladder calculi. Among 58 bladder-drained patients, reflux pancreatitis occurred in 28 patients and urine leaks related to the pancreatic graft occurred in 7 patients. Conversion of exocrine secretions from bladder to enteric diversion was required in 6 patients. One- and 3-year patient survival rates were 92.7% and 89.1%, respectively. Moreover, 1 and 3-year kidney graft survival rates were 90.6% and 84.4%, and pancreas graft survival rates were 78.1 and 70.3%, respectively.

CONCLUSION

Simultaneous kidney-pancreas transplantation with bladder drainage is associated with a high frequency of urological complications. Appropriate treatment can resolve most complications. In our opinion, both enteric and bladder drainage seemed to be safe and effective alternatives to manage pancreatic exocrine secretions.

Outcome of renal transplantation in adult patients with augmented bladders

OBJECTIVE

We studied the long-term renal graft functions, survivals, and complications among patients with augmented bladders.

PATIENTS AND METHODS

Between 1976 and 2008, we performed 6/2600 renal transplantations in patients with augmented bladders. The mean patient age was 52 years. The cause of end-stage renal disease was chronic interstitial kidney disease in all patients, being secondary to lower urinary tract dysfunction. The etiology of bladder dysfunction was tuberculosis in 4 cases, bladder exstrophy in 1, and myelomeningocele in 1. Enterocystoplasty had been performed at a mean of 19 years prior to transplantation. The ureter was implanted into the native ureter in 5 cases and the bowel segment in 1 case.

RESULTS

With a mean follow-up of 56 months (range, 20-100 months), the overall graft survival was 50%. Three grafts were lost due to venous thrombosis (n = 1), and chronic allograft nephropathy (n = 2) at 37 and 100 months posttransplantation. No patient died during follow-up. Mean serum creatinine was 1.44 mg/dL with Modification of Diet in Renal Disease (MDRD) clearance of 76 mL/min/1.73 m(2). One fistula that caused obstructive uropathy and 2 cases of migration of a double J catheter were among the surgical complications. These patients showed a mean of 7 episodes of uncomplicated urinary infections. Only 1 patient was rehospitalized due to a complicated urinary tract infection.

CONCLUSIONS

Patients with enterocystoplasty and renal transplantation show a greater risk of urinary tract infections, albeit mostly uncomplicated. Despite this, the long-term results are acceptable.