Pilot study comparing SPECT perfusion scintigraphy with CT pulmonary angiography in chronic thromboembolic pulmonary hypertension.

BACKGROUND AND OBJECTIVE: The management of chronic thromboembolic pulmonary hypertension (CTEPH) is dependent on the extent of pulmonary artery obstruction, which is usually evaluated by planar perfusion scanning and CT pulmonary angiography (CTPA). We previously reported that SPECT perfusion scanning is more sensitive than planar scanning for detecting vascular obstruction in CTEPH. The purpose of this study is to compare SPECT with CTPA for detecting segmental pulmonary artery obstruction in CTEPH. METHODS: SPECT and CTPA were carried out before pulmonary endarterectomy in 12 CTEPH patients. Field experts documented the anatomical distribution of perfusion defects disclosed by SPECT, the anatomical distribution of pulmonary arterial filling defects disclosed by CTPA and the segmental anatomy of the vascular obstructions based on a review of clinical and pathology records, without knowledge of scan results. RESULTS: Clinical/pathological evaluation disclosed 140 obstructed (15.5 ± 2.5 per patient) and 40 unobstructed lung segments. SPECT scanning identified 87/140 (62%) of the obstructed and 29/40 (72%) of the unobstructed segments. By comparison, CTPA identified 67/140 (47.8%) of the obstructed and 32/40 (80%) of the unobstructed segments. Sensitivity for detecting obstructed segments was significantly higher for SPECT compared with CTPA (62 ± 4.1% vs 47.8 ± 2.9%, respectively; P = 0.03). CONCLUSIONS: SPECT is more sensitive than CTPA for identifying obstructed segments in this small sample of CTEPH patients. However, even SPECT under-represents the extent of vascular obstruction from this disease.

The Utility of Brain Natriuretic Peptide in Patients Undergoing an Initial Evaluation for Pulmonary Hypertension.

Introduction: Brain natriuretic peptide (BNP) is a polypeptide released from the cardiac ventricles and has been used as a diagnostic marker in cardiovascular diseases. Some patients with pulmonary hypertension have significant increases in BNP levels. This study wanted to determine whether the BNP levels in patients referred for evaluation of possible pulmonary hypertension were associated with a particular functional class or diagnostic group. Methods: Data were collected on patients from the Pulmonary Vascular Disease clinic undergoing right heart catheterization between 1/1/2019 and 5/20/2020. Clinical information, laboratory results including BNP, and hemodynamic parameters were recorded. Results: This study included 117 patients referred for evaluation for PH with measured BNP levels. The mean age was 63; the female to male ratio was 2:1, 25.4% of the patients were Hispanic. The average BNP level for the entire cohort was 4127.1 ± 11761.98 pg/ml. Patients in higher WHO functional classes tended to have higher levels of BNP, but statistical analysis BNP showed no differences between the functional classes. Patients in WHO Group 4 had significantly higher BNP levels than other WHO groups. Hemodynamic group classification demonstrated significant differences in BNP values between the low, intermediate, and high composite score patients. Conclusions: Patients undergoing evaluation for pulmonary hypertension had a wide range of BNP values. Patients with more abnormal composite hemodynamic scores higher BNP levels. Measurement of BNP provides an independent test to help interpret patients' descriptions of their functional limitations and to identify patients with more abnormal hemodynamic parameters.

Correlation between echocardiographic measurements and right heart hemodynamic parameters in patients undergoing evaluation for pulmonary hypertension.

Echocardiograms provide important information for the evaluation and management of patients with pulmonary hypertension. Right ventricular free wall strain measurements provide additional information about the longitudinal contractile function of the right ventricle. Clinical information, including echocardiographic measurements and right heart hemodynamic parameters, on patients undergoing right heart catheterization for evaluation of possible pulmonary hypertension was collected retrospectively. This study included 60 patients (35 women) with a mean age of 62.6 ± 14.8 years. For World Health Organization categories, 32 patients were in Group 1, 12 in Group 2, 4 in Group 3, 3 in Group 4, and 7 had mixed clinical features of both Group 2 and Group 3. The mean pulmonary artery pressure was 40.6 ± 13.2 mm Hg. The right atrial volume index had significant positive correlations with the brain natriuretic peptide level, right ventricular volume index, left atrial volume index, and right atrial pressure and negative correlations with the cardiac index and mixed venous oxygen saturation. The mean right ventricular free wall strain was -17.85 ± 5.56%; it did not have significant correlations with right heart hemodynamic parameters. Therefore, the right atrial volume index but not the right ventricular strain index provides important objective information for the evaluation of patients with possible pulmonary hypertension.

Single photon emission computed tomography in chronic thromboembolic pulmonary hypertension.

BACKGROUND AND OBJECTIVE: The management of chronic thromboembolic pulmonary hypertension (CTEPH) is largely dependent on the extent of obstruction in the pulmonary arteries. Planar perfusion scans are commonly used to quantify perfusion defects in CTEPH patients. However, planar scans typically under-represent the extent of vascular obstruction in CTEPH. We conducted this study to test the hypothesis that SPECT lung perfusion scans are more accurate than planar scans for determining the location and extent of perfusion defects in patients with CTEPH. METHODS: Planar ventilation scans, planar and SPECT perfusion scans were performed preoperatively in patients undergoing pulmonary thromboendarterectomy for treatment of CTEPH. Two clinical experts independently documented the segmental anatomy of the vascular obstructions by reviewing clinical records, pulmonary and CT angiograms, and surgical specimens. A nuclear medicine expert documented the segmental anatomy of the perfusion defects observed by planar and SPECT scans independently. RESULTS: Clinical/pathological evaluation disclosed 241 obstructed and 99 unobstructed lung segments in 17 patients. Sensitivity for detecting obstructed segments was significantly higher for SPECT than for planar scanning (63.5 ± 3.1% vs. 42.7 ± 3.2%, respectively; P < 0.01). Specificities of SPECT and planar scanning were not significantly different (62.6 ± 4.8% vs. 76.8 ± 4.2%, respectively; P = 0.092). CONCLUSIONS: The SPECT is more sensitive than planar perfusion scanning for identifying obstructed segments in CTEPH. However, even SPECT under-represents the true extent of the vascular occlusions in CTEPH.

The clinical associations with cardiomegaly in patients undergoing evaluation for pulmonary hypertension.

BACKGROUND: Chest radiographs can identify important abnormalities in patients undergoing diagnostic evaluation for cardiovascular diseases. Cardiomegaly often reflects cardiac chamber dilation, or cardiac muscle hypertrophy, or both conditions. The clinical implications of cardiomegaly depend on the underlying clinical disorder. Does cardiomegaly have any clinical, laboratory, echocardiographic, and right heart catheterization associations in patients undergoing evaluation for pulmonary hypertension? METHODS: Patients referred to a pulmonary vascular disease clinic for possible pulmonary hypertension underwent a comprehensive evaluation that included right heart catheterization. These patients also had chest radiographs, laboratory studies, and echocardiograms. The patients were divided into two groups based on the presence or absence of cardiomegaly. RESULTS: This study included 102 patients (63.7% female) with a mean age of 62.3 ± 15.0 years. Patients with cardiomegaly (n = 64) had elevated BNP, BUN, and creatinine levels. They had elevated right atrial pressures, right ventricular pressures, and pulmonary artery pressures and reduced cardiac indices and reduced mixed venous oxygen saturations. There were no differences in echocardiographic parameters between the two groups. CONCLUSIONS: This study demonstrates that the presence of cardiomegaly on chest radiographs has important clinical implications, including increased BNP levels and increased right heart pressures, in patients undergoing evaluation for pulmonary hypertension. Consequently, the presence of cardiomegaly supports the need for additional evaluation, including right heart catheterization, and provides useful information for primary care physicians and specialists.

Results From the United States Chronic Thromboembolic Pulmonary Hypertension Registry: Enrollment Characteristics and 1-Year Follow-up.

BACKGROUND: The United States Chronic Thromboembolic Pulmonary Hypertension Registry (US-CTEPH-R) was designed to characterize the demographic characteristics, evaluation, clinical course, and outcomes of surgical and nonsurgical therapies for patients with chronic thromboembolic pulmonary hypertension. RESEARCH QUESTION: What are the differences in baseline characteristics and 1-year outcomes between operated and nonoperated subjects? STUDY DESIGN AND METHODS: This study describes a multicenter, prospective, longitudinal, observational registry of patients newly diagnosed (< 6 months) with CTEPH. Inclusion criteria required a mean pulmonary artery pressure ≥ 25 mm Hg documented by right heart catheterization and radiologic confirmation of CTEPH. Between 2015 and 2018, a total of 750 patients were enrolled and followed up biannually until 2019. RESULTS: Most patients with CTEPH (87.9%) reported a history of acute pulmonary embolism. CTEPH diagnosis delays were frequent (median, 10 months), and most patients reported World Health Organization functional class 3 status at enrollment with a median mean pulmonary artery pressure of 44 mm Hg. The registry cohort was subdivided into Operable patients undergoing pulmonary thromboendarterectomy (PTE) surgery (n = 566), Operable patients who did not undergo surgery (n = 88), and those who were Inoperable (n = 96). Inoperable patients were older than Operated patients; less likely to be obese; have a DVT history, non-type O blood group, or thrombophilia; and more likely to have COPD or a history of cancer. PTE resulted in a median pulmonary vascular resistance decline from 6.9 to 2.6 Wood units (P < .001) with a 3.9% in-hospital mortality. At 1-year follow-up, Operated patients were less likely treated with oxygen, diuretics, or pulmonary hypertension-targeted therapy compared with Inoperable patients. A larger percentage of Operated patients were World Health Organization functional class 1 or 2 at 1 year (82.9%) compared with the Inoperable (48.2%) and Operable/No Surgery (56%) groups (P < .001). INTERPRETATION: Differences exist in the clinical characteristics between patients who exhibited operable CTEPH and those who were inoperable, with the most favorable 1-year outcomes in those who underwent PTE surgery. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov; No.: NCT02429284; URL: www.clinicaltrials.gov.

Pulmonary hypertensive medical therapy in chronic thromboembolic pulmonary hypertension before pulmonary thromboendarterectomy.

BACKGROUND: The currently recommended treatment for chronic thromboembolic pulmonary hypertension is pulmonary thromboendarterectomy (PTE). No convincing evidence for the use of pulmonary hypertensive medical therapy (PHT) exists in operable candidates. We sought to determine the prevalence of the use of PHT on referral for PTE and the effects on pre-PTE hemodynamics and post-PTE outcomes/hemodynamics. METHODS AND RESULTS: We performed a retrospective analysis of chronic thromboembolic pulmonary hypertension patients referred for PTE during 2005-2007. The prevalence of PHT was determined for all patients referred to our institution. Hemodynamic and outcomes analysis involved only those undergoing PTE. Data included baseline demographics, PHT medication(s), dosage, duration of therapy, and time to referral. Hemodynamic data were acquired from the time of diagnosis, the time of referral visit, and after PTE. Outcomes included intensive care unit, hospital, and ventilator days; bleeding and infection rates; incidence of reperfusion lung injury; and in-hospital mortality. The control group (n=244) was compared with the PHT group (n=111); subgroups included monotherapy with bosentan, sildenafil, or epoprostenol and combination therapy. The prevalence of PHT significantly increased from 19.9% in 2005 to 37% in 2007. There was minimal benefit of treatment with PHT on pre-PTE mean pulmonary artery pressure, but its use was associated with a significant delay in time to referral for PTE. Both groups experienced significant improvements in hemodynamic parameters after PTE. The 2 groups did not differ significantly in any post-PTE outcome. Similar results were obtained for each subgroup. CONCLUSIONS: Our results suggest that PHT use has minimal effect on pre-PTE hemodynamics and no effect on post-PTE outcomes/hemodynamics.

The evolution of health care in the Texas correctional system and the impact of COVID-19.

Health care under the jurisdiction of the Texas Department of Criminal Justice has evolved over time to provide prisoners greater access to medical care, including psychiatric care and substance abuse assistance. Mental illness and chronic conditions, such as hypertension, chronic obstructive pulmonary disease, diabetes, and heart disease, are common in prisoners in Texas and across the nation and increase the cost of health care. The average annual health care cost per prisoner in Texas was $4077 in 2015. Although the Texas prison system has undergone changes, such as the use of telemedicine and protocols for preventive measures, to address the varying medical needs of prisoners in correctional facilities, there is still considerable criticism regarding prison policies and incomplete access to medical care. In addition, the ongoing COVID-19 pandemic has added significant stress to correctional health care in Texas and highlights the importance of organized health care for prisoners. This report reviews the history and evolution of health care delivery in Texas's correctional facilities, outlines ongoing efforts to improve medical care in prison facilities, and describes current policies to limit COVID-19 infections in Texas prisons.

A Retrospective Analysis and Comparison of Prisoners and Community-Based Patients with COVID-19 Requiring Intensive Care During the First Phase of the Pandemic in West Texas.

BACKGROUND: COVID-19 is a highly infectious disease which usually presents with respiratory symptoms. This virus is disseminated through respiratory droplets, and, therefore, individuals residing in close quarters are at a higher risk for the acquisition of infection. The prison population is at a significantly increased risk for infection. METHODS: Prisoners from the Montford Correctional facility in Lubbock, Texas, hospitalized in the medical intensive care unit at University Medical Center between March 1, 2020 and May 15, 2020 were compared to community-based patients hospitalized in the same medical intensive care unit. Clinical information, laboratory results, radiographic results, management requirements, and outcomes were compared. RESULTS: A total of 15 community-based patients with a mean age of 67.4 ± 15.5 years were compared to 5 prisoners with a mean age of 56.0 ± 9.0 years. All prisoners were men; 10 community-based patients were men. Prisoners presented with fever, dyspnea, and GI symptoms. The mean number of comorbidities in prisoners was 2.4 compared to 1.8 in community-based patients. Prisoners had significantly lower heart rates and respiratory rates at presentation than community-based patients. The mean length of stay in prisoners was 12.6 ± 8.9 days; the mean length of stay in community-based patients was 8.6 ± 6.5. The case fatality rate was 60% in both groups. CONCLUSIONS: Prisoners were younger than community-based patients but required longer lengths of stay and had the same mortality rate. This study provides a basis for comparisons with future studies which could involve new treatment options currently under study.

Basic Demographic Parameters Help Predict Outcomes in Patients Hospitalized With COVID-19 During the First Wave of Infection in West Texas.

The severity of COVID-19 ranges from asymptomatic subclinical infections to severe acute respiratory failure requiring mechanical ventilation. Patients admitted to the hospital have increased mortality rates and patients requiring intensive care have significantly increased mortality rates. Multiple factors influence these outcomes. This study used simple demographic information available on admission to evaluate possible associations between these variables and outcomes, including mortality and length of stay. Clinical outcomes in 63 patients admitted to a tertiary care hospital in West Texas were reviewed. Older patients, patients admitted from nursing homes, and patients admitted to medical intensive care units had increased mortality. Unadjusted analysis indicated that males had increased mortality. Adjusted analysis indicated that males spent nearly 5 days longer in the hospital than females. In summary, age, chronic illness requiring nursing home placement, and acute severe illness requiring intensive care unit admission identify patients with worse prognoses. In addition, males will likely have a longer length of hospital stay.

Prevalence of Coronavirus Antibody Among First Responders in Lubbock, Texas.

BACKGROUND: The ongoing coronavirus disease (COVID-19) pandemic has a major impact on first responders. Scarce personal protective equipment (PPE) has forced them to conserve and reuse some of their PPE. The efficacy of these practices in preventing transmission of COVID-19 from patients to first responders is unclear. There are limited data on the prevalence of antibodies specific for COVID-19 exposure in these front-line workers. AIM: Our objective was to determine the prevalence of positive immunoglobulin G antibody specific to COVID-19 among first responders in Lubbock, Texas. METHODS: Blood samples were collected on 683 asymptomatic first responders who work in Lubbock, Texas and the surrounding area, after informed consents were signed. IgG antibody to SARS-CoV-2 was measured using Abbott's SARS-CoV-2 IgG Reagent Kit in combination with the SARS-CoV-2 IgG Calibrator Kit on the Abbott's ARCHITECT i1000SR analyzer. RESULTS: The prevalence of IgG specific antibodies to COVID-19 was 0.73%, five of the 683 participants tested positive. Four of those who tested positive had no known prior SARS-CoV-2 infection or exposure without adequate PPE. CONCLUSIONS: The prevalence of IgG specific antibodies to COVID-19 was much lower than expected in our study population despite high sensitivity and specificity of the test reagent. The most likely explanations for this finding include limited exposure, inadequate time for a IgG response, possible clearance of COVID-19 infection locally by the respiratory tract IgA defense system without eliciting a systemic IgG response, and short persistence of IgG antibodies in mild or asymptomatic cases.

Analysis of Glucose Levels in Patients Hospitalized With COVID-19 During the First Phase of This Pandemic in West Texas.

BACKGROUND: Patients with hyperglycemia during hospitalization, especially during ICU hospitalizations, often have worse outcomes, even if they do not have a premorbid diagnosis of diabetes. High glucose levels can provide insight into the underlying pathogenesis of a disease and can contribute to tissue injury. Some patients with COVID-19 have hyperglycemia during hospitalizations. METHODS: The Infectious Disease and Control office at University Medical Center in Lubbock, Texas, provided a list of patients with a COVID-19 infection hospitalized between March 1 and May 15, 2020. The medical records were reviewed to collect information on age, gender, history of diabetes, and glucose levels on admission and through the first 7 days of hospitalization. RESULTS: This study included 63 patients with a mean age of 62.1 ± 14.1 years. Thirty-five patients (55.6%) were males. The in-hospital mortality rate was 30.2%. The mean admission glucose level was 129.4 ± 57.1 mg/dL in patients who survived (N = 47) and 189.6 ± 112.2 mg/dL in patients who died during hospitalization (N = 16, P = .007). An admission glucose greater than 180 mg/dL predicted mortality in a model adjusted for a diabetes, age, and male gender. The mean differences between the maximum and minimum glucose levels calculated over the first 7 days of hospitalization were 112.93 ± 115.4 (N = 47) in patients who survived and were 240.5 ± 97.7 (N = 15) in patients who died during hospitalization (P = .0003). A difference between the maximum and minimum glucose level greater than 105 mg/dL was associated with increased mortality. CONCLUSIONS: Patients who died during hospitalization for COVID-19 had higher admission glucose levels than patients who survived. Larger differences between maximum and minimum glucose levels during the first 7 days of hospitalization were associated with increased mortality. These results suggest that high glucose levels identify patients at increased risk for mortality and warrant more study.

Management of Low-Risk Pulmonary Embolism.

Pulmonary embolism remains a leading cause of morbidity and mortality in the United States. However, with improved recognition and diagnosis, the risk of death diminishes. The diagnosis depends on the clinician's suspicion. Pulmonary emboli are categorized into low, intermediate, or high risk based on the scoring scales and patients' hemodynamic stability versus instability. Imaging plus biomarkers help stratify patients according to risk. With the advent of the computed tomography multidetector scanners, the improved imaging has increased the detection of subsegmental and incidental pulmonary emboli. Treatment of low-risk as well as subsegmental and incidental pulmonary embolism is evolving.

The Complexity of Characteristics, Diagnoses and Treatment of Older Patients With Pulmonary Hypertension.

BACKGROUND: Older patients with pulmonary hypertension (PH) are more likely to have complex comorbidity than younger patients with pulmonary arterial hypertension (PAH). The best approach to the evaluation and management of these patients is unclear. METHODS: We, retrospectively, reviewed the clinical records of patients older than 60 years referred for evaluation for PAH. We recorded patient demographics, comorbidity, functional classification (FC), right heart catheterization data, echocardiographic data, chest radiographic images and pulmonary function results. We recorded the final diagnoses according to World Health Organization (WHO) subgroups and treatment outcomes based on changes in FC. RESULTS: Ninety-seven records were reviewed in detail. The mean age was 71.2 ± 7.5 years with 66% women. Cardiovascular disease was the most frequent comorbidity. Mean PA pressure by catheterization was 39.5 ± 12.2mmHg (n = 65). The overall distribution after evaluation included 21 (21.6%) Group 1, 35 (36.1%) Group 2, 16 (16.5%) Group 3, 18 (18.6%) mixed Group 2 and 3, 6 (6.2%) Group 4 and 1 (1%) Group 5 patients. Group 1 patients were treated with PAH specific drug, and 12 patients had an improvement in FC with treatment. CONCLUSIONS: Older patients with suspected PH often have significant cardiovascular and respiratory comorbidity. Comprehensive evaluations are needed to determine the severity of PH and associated diseases and to initiate treatment focused on FC. Patients in WHO Group 2 and mixed Group 2 and 3 were frequently identified and constituted a diagnostic and treatment challenge in this study. Older patients with PAH may benefit from PAH specific drugs.

Chronic thromboembolic pulmonary hypertension.

The description of organized thrombus in major pulmonary arteries can be found in autopsy reports dating back to the late nineteenth and early twentieth centuries. Not until the 1950s was the antemortem diagnosis and clinical syndrome of chronic thrombotic obstruction of the major pulmonary arteries better characterized. The first surgical attempt to remove the adherent thrombus from the vessel wall occurred in 1958. This operation provided the conceptual foundation for the distinction between acute and chronic thromboembolic disease of the pulmonary vascular bed, and established that an endarterectomy, and not an embolectomy, would be necessary if a surgical remedy for this disease was to be successful.

Pulmonary veno-occlusive disease: An important consideration in patients with pulmonary hypertension.

Pulmonary veno-occlusive disease is a rare subcategory of pulmonary arterial hypertension (WHO Group 1). The disease is poorly understood and difficult to diagnose; it has no definitive cure to date. These patients present with nonspecific symptoms, including dyspnea, exercise intolerance, and weakness. Chest x-rays sometimes differ from idiopathic pulmonary arterial hypertension and may demonstrate alveolar infiltrates and pleural effusions. High resolution computed tomography scans reveal ground glass opacities, interlobular septal thickening, and lymphadenopathy. Echocardiography can estimate the level of pulmonary artery pressures; right heart catheterization is needed for complete hemodynamic characterization of these patients. Lung biopsies demonstrate remodeling of the venules and small veins with intimal and adventitial fibrosis. This can result in total venous occlusion and subsequent recanalization. Similar changes occur in the small arteries and arterioles but are less pronounced than the venous changes. There is no effective medical therapy for these patients, and treatment with the pulmonary arterial hypertension specific medications often causes acute deterioration with pulmonary edema. The recent discovery of the biallelic mutations of the EIF2AK4 gene as an etiology for heritable form of pulmonary veno-occlusive disease increases our understanding of the disease pathogenesis and potentially identifies a future approach to treatment. Without definitive treatment, the prognosis is very poor, and the life expectancy of these patients is much shorter than patients with pulmonary arterial hypertension. These patients need early referral to transplantation centers.

Pulmonary vein stenosis complicating radiofrequency catheter ablation for atrial fibrillation: A literature review.

Radiofrequency catheter ablation has become a widely used intervention in the treatment of atrial fibrillation. Pulmonary vein stenosis (PVS) is one of the most serious complications associated with this procedure; the degree of stenosis ranges from mild (<50%) to complete venous occlusion. The natural history of PVS and the risk of progression of existing PVS are uncertain. Symptomatic and/or severe PVS is a serious medical problem and can be easily misdiagnosed since it is an uncommon and relatively new medical problem, often has low clinical suspicion among clinicians, and has a non-specific presentation that mimics other more common respiratory or cardiac diseases. The estimated incidence varies in literature reports from 0% to 42% of ablation procedures, depending on technical aspects of the procedure and operator skill. Most patients with significant PVS remain asymptomatic or have few symptoms. Symptomatic patients usually present with dyspnea, chest pain, or hemoptysis and are usually treated with balloon angioplasty and/or stent placement. Little is known about the long term effect of PV stenosis/occlusion on the pulmonary circulation and the development of pulmonary hypertension. Evolving technology may reduce the frequency of this complication, but long term studies are needed to understand the effect of therapeutic atrial injury and adverse outcomes. This review summarizes the current literature and outlines an approach to the evaluation and management of these patients.

Choriocarcinoma presenting with thyrotoxicosis.

We describe a 26-year-old man with metastatic choriocarcinoma who presented with hyperthyroidism associated with elevated ß-human chorionic gonadotropin (B-HCG) and respiratory failure secondary to diffuse lung metastasis. After the first cycle of chemotherapy, the concentration of B-HCG dramatically decreased and the patient became euthyroid, allowing us to discontinue antithyroid medications. The patient's hyperthyroidism was caused by stimulation of the thyroid gland by high B-HCG levels, as shown by the marked improvement of the patient's thyroid function panel after chemotherapy.