Central pulmonary artery lesions in chronic obstructive pulmonary disease: A transesophageal echocardiography study

Pulmonary Embolism and Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a frequent and devastating chronic respiratory disease. COPD is ranked among the top five causes of death worldwide. Patients with COPD suffer from persistent dyspnea, with periods of acute worsening, called exacerbations. Such exacerbations may be severe. In fact, one-third of COPD patients will be hospitalized because of an exacerbation. Hospitalization due to respiratory failure has been identified as a powerful predisposing risk factor for venous thromboembolism (VTE) for many years. Therefore, COPD is recognized as a moderate risk factor for VTE, with an odds ratio between 2 and 9, similar to other risk factors such as estrogen-containing contraceptives or (any) cancer. However, unlike other risk factors such as contraception, the presence of COPD can modify the initial presentation of VTE and worsen the short-term prognosis of patients who have acute pulmonary embolism (PE), particularly during a COPD exacerbation. It is not only that both stable COPD and acute exacerbations of COPD might increase the risk of VTE, but PE itself may mimic the symptoms of a COPD exacerbation. Hence, some authors have evaluated the prevalence of PE among COPD patients with acute worsening. This clinical review (1) gives an update on epidemiological data, clinical presentation, and prognosis of PE associated with COPD; (2) presents the results of the Prevalence de l'Embolie Pulmonaire chez les patients admis pour exacerbation de BPCO study, which aimed at determining the frequency of PE in COPD patients hospitalized for an acute exacerbation; (3) discusses the results of the Significance of Pulmonary Embolism in COPD Exacerbations study, the first randomized trial having compared the efficacy of a systematic search for PE versus routine care on admission for a COPD exacerbation; and (4) provides a selection of remaining unmet needs on the association between COPD and PE.

Interplay of Low-Density Lipoprotein Receptors, LRPs, and Lipoproteins in Pulmonary Hypertension

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LDLR regulates oxidized LDL level, which is increased in lung and blood from PAH patients.

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LRP1 preserving vascular homeostasis is decreased in PAH patients.

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LRP5/6 regulating Wnt signaling is upregulated in PH.

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The LRP8 (aka ApoER2) ligand ApoE protects from PAH.

The low-density lipoprotein receptor (LDLR) gene family includes LDLR, very LDLR, and LDL receptor–related proteins (LRPs) such as LRP1, LRP1b (aka LRP-DIT), LRP2 (aka megalin), LRP4, and LRP5/6, and LRP8 (aka ApoER2). LDLR family members constitute a class of closely related multifunctional, transmembrane receptors, with diverse functions, from embryonic development to cancer, lipid metabolism, and cardiovascular homeostasis. While LDLR family members have been studied extensively in the systemic circulation in the context of atherosclerosis, their roles in pulmonary arterial hypertension (PAH) are understudied and largely unknown. Endothelial dysfunction, tissue infiltration of monocytes, and proliferation of pulmonary artery smooth muscle cells are hallmarks of PAH, leading to vascular remodeling, obliteration, increased pulmonary vascular resistance, heart failure, and death. LDLR family members are entangled with the aforementioned detrimental processes by controlling many pathways that are dysregulated in PAH; these include lipid metabolism and oxidation, but also platelet-derived growth factor, transforming growth factor β1, Wnt, apolipoprotein E, bone morpohogenetic proteins, and peroxisome proliferator-activated receptor gamma. In this paper, we discuss the current knowledge on LDLR family members in PAH. We also review mechanisms and drugs discovered in biological contexts and diseases other than PAH that are likely very relevant in the hypertensive pulmonary vasculature and the future care of patients with PAH or other chronic, progressive, debilitating cardiovascular diseases.

Prevalence and predictors of pulmonary embolism in patients with acute exacerbation of chronic obstructive pulmonary disease

Background:

The prevalence of pulmonary embolism (PE) in patients of acute exacerbation of chronic obstructive pulmonary disease (AECOPD) varies over a wide range. Early detection and treatment of PE in AECOPD is a key to improve patient outcome. The purpose of the study was to investigate the prevalence and predictors of PE in patients of AECOPD in a high burden region of North India.

Materials and Methods:

This prospective study included patients of AECOPD with no obvious cause of exacerbation on initial evaluation. Apart from routine workup, the participants underwent assessment of D-dimer, compression ultrasound and venous Doppler ultrasound of the lower limbs and pelvic veins, and a multidetector computed tomography pulmonary angiography.

Results:

A total of 100 patients of AECOPD with unknown etiology were included. PE as a possible cause of AE-COPD was observed in 14% of patients. Among the participants with PE, 63% (n = 9) had a concomitant presence of lower extremity deep venous thrombosis. Hemoptysis and chest pain were significantly higher in patients of AECOPD with PE ([35.7% vs. 7%, P = 0.002] and [92.9% vs. 38.4%, P = 0.001]). Likelihood of PE was significantly higher in patients who presented with tachycardia, tachypnea, respiratory alkalosis (PaCO2 <45 mmHg and pH >7.45), and hypotension. No difference was observed between the two groups in terms of in-hospital mortality, age, sex distribution, and risk factors for embolism except for the previous history of venous thromboembolism (35.7% vs. 12.8% P = 0.03).

Conclusion:

PE was probably responsible for AECOPD in 14% of patients with no obvious cause on initial assessment. Patients who present with chest pain, hemoptysis, tachypnea, tachycardia, and respiratory alkalosis should be particularly screened for PE.

Influence of Intermittent Hypoxia/Hypercapnia on Atherosclerosis, Gut Microbiome, and Metabolome

Obstructive sleep apnea (OSA), a common sleep disorder characterized by intermittent hypoxia and hypercapnia (IHC), increases atherosclerosis risk. However, the contribution of intermittent hypoxia (IH) or intermittent hypercapnia (IC) in promoting atherosclerosis remains unclear. Since gut microbiota and metabolites have been implicated in atherosclerosis, we examined whether IH or IC alters the microbiome and metabolome to induce a pro-atherosclerotic state. Apolipoprotein E deficient mice (ApoE-/- ), treated with IH or IC on a high-fat diet (HFD) for 10 weeks, were compared to Air controls. Atherosclerotic lesions were examined, gut microbiome was profiled using 16S rRNA gene amplicon sequencing and metabolome was assessed by untargeted mass spectrometry. In the aorta, IC-induced atherosclerosis was significantly greater than IH and Air controls (aorta, IC 11.1 ± 0.7% vs. IH 7.6 ± 0.4%, p < 0.05 vs. Air 8.1 ± 0.8%, p < 0.05). In the pulmonary artery (PA), however, IH, IC, and Air were significantly different from each other in atherosclerotic formation with the largest lesion observed under IH (PA, IH 40.9 ± 2.0% vs. IC 20.1 ± 2.6% vs. Air 12.2 ± 1.5%, p < 0.05). The most differentially abundant microbial families (p < 0.001) were Peptostreptococcaceae, Ruminococcaceae, and Erysipelotrichaceae. The most differentially abundant metabolites (p < 0.001) were tauro-β-muricholic acid, ursodeoxycholic acid, and lysophosphoethanolamine (18:0). We conclude that IH and IC (a) modulate atherosclerosis progression differently in distinct vascular beds with IC, unlike IH, facilitating atherosclerosis in both aorta and PA and (b) promote an atherosclerotic luminal gut environment that is more evident in IH than IC. We speculate that the resulting changes in the gut metabolome and microbiome interact differently with distinct vascular beds.

An Unusually Rare but Interesting Co-Occurrence of Idiopathic Pulmonary Artery and Pulmonary Vein Thrombosis: A Case Report

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Concomitant in situ pulmonary artery and vein thrombosis is a unique event.

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This situation can lead to chronic severe and life-threatening respiratory failure.

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Surgical removal of clots can be lifesaving in severe cases.

Intermittent hypoxia and hypercapnia induces inhibitor of nuclear factor-κB kinase subunit β-dependent atherosclerosis in pulmonary arteries

Clinical studies have shown that obstructive sleep apnea (OSA) increases atherosclerosis risk. The inflammation, especially mediated by the macrophages via nuclear factor-κB (NF-κB), has been speculated to contribute to atherogenicity in OSA patients. Inhibitor of NF-κB kinase-β (IKKβ) is an essential element of the NF-κB pathway and is linked to atherosclerosis. We previously reported that atherosclerosis was accelerated in pulmonary artery (PA) but not in aorta when low-density lipoprotein receptor knockout (Ldlr-/-) mice were exposed to intermittent hypoxia/hypercapnia (IHH), a surrogate for recurrent upper-airway obstruction. Therefore, we hypothesized that IKKβ-dependent NF-κB activation in monocytes and macrophages plays a role in IHH-induced PA atherosclerosis. To test this hypothesis, myeloid restricted IKKβ deletion (IkkβΔMye) or control (IkkβF/F) mice were crossed with Ldlr-/- mice to generate double-knockout mice. Then, the mice were exposed to IHH or room air (Air) on high-fat diet for 8 or 16 wk. Lesions of PA and aorta were examined in IkkβΔMye;Ldlr-/- and IkkβF/F;Ldlr-/- male mice under IHH vs. Air. The results revealed that IKKβ deletion abolished IHH-induced PA atherosclerosis after 8-wk exposure but not after 16-wk exposure (8 wk: IkkβF/F;Ldlr-/-, IHH 13.5 ± 1.4 vs. Air 5.7 ± 0.7%, P < 0.01; IkkβΔMye;Ldlr-/-, IHH 7.4 ± 1.9% vs. Air 4.6 ± 1.3%, P = 0.24). Both IKKβ deletion and IHH had no effects on atherosclerosis in the aorta. Our findings demonstrate that IKKβ-dependent NF-κB activity in myeloid-lineage cells plays a critical role in IHH-induced PA atherosclerosis at the early stage.

Distribution of atherosclerotic lesions in various arteries of WHHLMI rabbits, an animal model of familial hypercholesterolemia

In WHHLMI rabbits, arterial lesions develop spontaneously in various arteries even with standard chow. Here, we examined the development of arterial lesions in various arteries to demonstrate standard characteristics of arterial lesions in WHHLMI rabbits. For WHHLMI rabbits at 6, 12, 20, and 30 months of age, lesion areas and areas of arterial lumen surfaces were measured using image analysis software. Histopathological sections of arterial lesions were stained with elastic van Gieson staining. Arterial lesions developed around bifurcations and expanded with aging. In the aorta, atheromatous lesions were severe in the thoracic aorta but were mild in the distal part of the abdominal aorta. Carotid artery lesions progressed in the proximal region and at bifurcations, and the histopathological features were similar to those of coronary lesions. Pulmonary artery lesions contained many foam cells. Fibrous lesions were observed in the proximal and distal areas of the renal arteries, at the bifurcation of the iliac-femoral artery and mesenteric artery, and around the anastomosis of vertebral arteries. Lesions in the celiac artery contained foam cells and/or lipid droplets within fibrous lesions. In a pair of right and left arteries, the arterial lesions tended to progress more in the right artery. Gender did not affect analysis of arterial lesions. In conclusion, the arterial lesions expanded from bifurcations, and the morphological features of the arterial lesions varied depending on the type of artery. These results serve as reference data for arterial lesions in studies using WHHLMI rabbits.

Pulmonary Embolism in Patients with Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Objective

In most countries, nearly 6% of the adults are suffering from chronic obstructive pulmonary disease (COPD), which puts a huge economic burden on the society. Moreover, COPD has been considered as an independent risk factor for pulmonary embolism (PE). In this review, we summarized the existing evidence that demonstrates the associations between COPD exacerbation and PE from various aspects, including epidemiology, pathophysiological changes, risk factors, clinical features, management, and prognosis.

Data Sources

We searched the terms "chronic obstructive pulmonary disease," "pulmonary embolism," "exacerbations," and "thromboembolic" in PubMed database and collected the results up to April 2018. The language was limited to English.

Study Selection

We thoroughly examined the titles and abstracts of all studies that met our search strategy. The data from prospective studies, meta-analyses, retrospective studies, and recent reviews were selected for preparing this review.

Results

The prevalence of PE in patients with COPD exacerbation varied a lot among different studies, mainly due to the variations in race, sample size, study design, research setting, and enrollment criteria. Overall, whites and African Americans showed significantly higher prevalence of PE than Asian people, and the hospitalized patients showed higher prevalence of PE compared to those who were evaluated in emergency department. PE is easily overlooked in patients with COPD exacerbation due to the similar clinical symptoms. However, several factors have been identified to contribute to the increased risk of PE during COPD exacerbation. Obesity and lower limb asymmetry were described as independent predictors for PE. Moreover, due to the high risk of PE, thromboprophylaxis has been used as an important treatment for hospitalized patients with COPD exacerbation.

Conclusions

According to the previous studies, COPD patients with PE experienced an increased risk of death and prolonged length of hospital stay. Therefore, the thromboembolic risk in patients with acute exacerbation of COPD, especially in the hospitalized patients, should carefully be evaluated.

Intermittent Hypoxia and Hypercapnia Accelerate Atherosclerosis, Partially via Trimethylamine-Oxide

Obstructive sleep apnea (OSA) is a common disorder characterized by intermittent hypoxia and hypercapnia (IHC) during sleep. OSA has been shown to be a risk factor for atherosclerosis, but the relation of IHC to the induction or progression of atherosclerosis is not well understood. To dissect the mechanisms involved, we compared atherosclerotic lesion formation in two mouse models, i.e., apolipoprotein E (ApoE) and low density lipoprotein receptor (Ldlr)-deficient mice, with or without IHC exposure. Ten-week-old ApoE-/- or Ldlr-/- mice were fed a high-fat diet for 4 or 8 weeks while being exposed to IHC for 10 hours/day or room air (RA) for 24 hours/day. En face lesions of the aorta, aortic arch, and pulmonary artery (PA) were examined. Moreover, 3,3-dimethyl-1-butanol (DMB), an inhibitor of microbial trimethylamine (TMA) production, was used to determine the contribution of TMA-oxide (TMAO) to IHC-induced atherosclerosis. Eight weeks of IHC exposure expedited the formation of atherosclerosis in both the PA and aortic arch of ApoE-/- mice, but only in the PA of Ldlr-/- mice (ApoE-/- PA 8 wk, IHC 35.4 ± 1.9% versus RA 8.0 ± 2.8%, P < 0.01). The atherosclerotic lesions evolved faster and to a more severe extent in ApoE-/- mice as compared with Ldlr-/- mice (PA IHC 8 wk, ApoE-/- 35.4 ± 1.9% versus Ldlr-/- 8.2 ± 1.5%, P < 0.01). DMB significantly attenuated but did not totally eliminate IHC-induced PA atherosclerosis. Our findings suggest that IHC, a hallmark of OSA, accelerates the progression of atherosclerosis in the aorta and especially in the PA. This process is partly inhibited by DMB, demonstrating that microbial metabolites may serve as therapeutic targets for OSA-induced atherosclerosis.

Pulmonary Endarterectomy

Chronic thromboembolic pulmonary hypertension (CTEPH) results from recurrent or incomplete resolution of pulmonary embolism. CTEPH is much more common than generally appreciated. Although pulmonary embolism (PE) affects a large number of Americans, chronic pulmonary hypertension (PH) remains underdiagnosed. It is imperative that all patients with PH be screened for the presence of CTEPH since this form of PH is potentially curable with pulmonary thromboendarterectomy (PTE) surgery. The success of this procedure depends greatly on the collaboration of a multidisciplinary team approach that includes pulmonary medicine, cardiothoracic surgery, and cardiac anesthesiology. This review, based on the experience of more than 3000 pulmonary endarterectomy surgeries, is divided into 2 parts. Part I focuses on the clinical history and pathophysiology, diagnostic workup, and intraoperative echocardiography. Part II focuses on the surgical approach, anesthetic management, postoperative care, and complications.

Role of intravascular ultrasound in unprotected left main percutaneous coronary intervention

Percutaneous coronary intervention (PCI) to the unprotected left main stem offers an attractive alternative to bypass grafting, but is associated with a significant clinical risk and therefore demands special consideration. Successful left main PCI is dependent upon the morphology of the lesion and the technical quality of the procedure. For these reasons, intravascular ultrasound (IVUS) has been the most popular adjunct to coronary angiography during left main PCI. However, trials of IVUS in left main PCI have produced inconclusive results, and most data predate the use of drug-eluting stents. Despite this, IVUS offers practical benefits in both case selection, and in guiding angioplasty and stenting. Here, we review the arguments for the present and future role of IVUS in left main PCI.

Chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is a disease with high mortality and few treatment options. This article reviews the epidemiology of CTEPH and identifies risk factors for its development. The pathobiology and the progression from thromboembolic events to chronically increased right-sided pressures are discussed. The diagnosis and assessment of CTEPH requires several modalities and the role of these is detailed. The pre-operative evaluation assesses peri-operative risk and determines the likelihood of benefit from PTE. Pulmonary thromboendarterectomy (PTE) remains the treatment of choice in appropriate patients. Nonsurgical therapies for CTEPH may provide benefit in patients who cannot be offered surgery.

Intermittent hypoxia and hypercapnia induce pulmonary artery atherosclerosis and ventricular dysfunction in low density lipoprotein receptor deficient mice

Patients with obstructive sleep apnea, who experience episodic hypoxia and hypercapnia during sleep, often demonstrate increased inflammation, oxidative stress, and dyslipidemia. We hypothesized that sleep apnea patients would be predisposed to the development of atherosclerosis. To dissect the mechanisms involved, we developed an animal model in mice whereby we expose mice to intermittent hypoxia/hypercapnia (IHH) in normobaric environments. Two- to three-month-old low-density lipoprotein receptor deficient (Ldlr(-/-)) mice were fed a high-fat diet for 8 or 16 wk while being exposed to IHH for either 10 h/day or 24 h/day. Plasma lipid levels, pulmonary artery and aortic atherosclerotic lesions, and cardiac function were then assayed. Surprisingly, atherosclerosis in the aorta of IHH mice was similar compared with controls. However, in IHH mice, atherosclerosis was markedly increased in the trunk and proximal branches of the pulmonary artery of exposed mice; even though plasma cholesterol and triglycerides were lower than in controls. Hemodynamic analysis revealed that right ventricular maximum pressure and isovolumic relaxation constant were significantly increased in IHH exposed mice and left ventricular % fractional shortening was reduced. In conclusion, 1) Intermittent hypoxia/hypercapnia remarkably accelerated atherosclerotic lesions in the pulmonary artery of Ldlr(-/-) mice and 2) increased lesion formation in the pulmonary artery was associated with right and left ventricular dysfunction. These findings raise the possibility that patients with obstructive sleep apnea may be susceptible to atherosclerotic disease in the pulmonary vasculature, an observation that has not been previously recognized.

Accidental pulmonary emboli noted by TEE during aortic valve replacement: a case report

Pulmonary embolism (PE) is difficult to diagnose clinically. In a patient who was scheduled for elective aortic valve replacement, several fresh emboli were recognized in the right atrium on transesophageal echocardiography (TEE). The PEs then disappeared on the echocardiographic image, with significant immediate hemodynamic changes noted by real-time monitors, such as tachycardia and increased pulmonary artery (PA) pressure. Pulmonary embolism was highly suspected. After cardiopulmonary bypass and aortic valve replacement, PA thromboembolectomy was performed successfully. The patient survived and was discharged from the hospital 17 days later without sequelae.

Prevalence of pulmonary embolism in acute exacerbations of COPD: a systematic review and metaanalysis

BACKGROUND

Nearly 30% of all exacerbations of COPD do not have a clear etiology. Although pulmonary embolism (PE) can exacerbate respiratory symptoms such as dyspnea and chest pain, and COPD patients are at a high risk for PE due to a variety of factors including limited mobility, inflammation, and comorbidities, the prevalence of PE during exacerbations is uncertain.

METHODS

A systematic review of the literature was performed to determine the reported prevalence of PE in acute exacerbations of COPD in patients who did and did not require hospitalization. The literature search was performed using MEDLINE, CINAHL, and EMBASE, and complemented by hand searches of bibliographies. Only cross-sectional or prospective studies that used CT scanning or pulmonary angiography for PE diagnosis were included.

RESULTS

Of the 2,407 articles identified, 5 met the inclusion criteria (sample size, 550 patients). Overall, the prevalence of PE was 19.9% (95% confidence interval [CI], 6.7 to 33.0%; p = 0.014). In hospitalized patients, the prevalence was higher at 24.7% (95% CI, 17.9 to 31.4%; p = 0.001) than those who were evaluated in the emergency department (3.3%). Presenting symptoms and signs were similar between patients who did and did not have PE.

CONCLUSIONS

One of four COPD patients who require hospitalization for an acute exacerbation may have PE. A diagnosis of PE should be considered in patients with exacerbation severe enough to warrant hospitalization, especially in those with an intermediate-to-high pretest probability of PE.

Mechanisms of atherothrombosis in chronic obstructive pulmonary disease

Patients affected by chronic obstructive pulmonary disease (COPD) have an increased risk of atherothrombotic acute events, independent of smoking and other cardiovascular risk factors. As a consequence, myocardial ischemia is a relevant cause of death in these patients. We reviewed studies concerning the potential mechanisms of atherothrombosis in COPD. Bronchial inflammation spreads to the systemic circulation and is known to play a key role in plaque formation and rupture. In fact, C-reactive protein blood levels increase in COPD and provide independent prognostic information. Systemic inflammation is the first cause of the hypercoagulable state commonly observed in COPD. Furthermore, hypoxia is supposed to activate platelets, thus accounting for the increased urinary excretion of platelet-derived thromboxane in COPD. The potential metabolic risk in COPD is still debated, in that recent studies do not support an association between COPD and diabetes mellitus. Finally, oxidative stress contributes to the pathogenesis of COPD and may promote oxidation of low-density-lipoproteins with foam cells formation. Retrospective observations suggest that inhaled corticosteroids may reduce atherothrombotic mortality by attenuating systemic inflammation, but this benefit needs confirmation in ongoing randomized controlled trials. Physicians approaching COPD patients should always be aware of the systemic vascular implications of this disease.

Does IVUS guidance of coronary interventions affect outcome? a prime example of the failure of randomized clinical trials

There has been a decline in the role of intravascular ultrasound (IVUS) guiding stenting. IVUS has lost favor with interventional cardiologists largely due to the emergence of drug eluting stents (DES). The advent of DES has lowered the need to maximize the final result due to the known low late-loss. This phenomenon has contributed to reduced interest in optimizing results with IVUS guidance. However, current concerns regarding stent thrombosis in relation to DES and its associated significant morbidity and mortality has once more focused attention on optimal stent deployment. Prior to DES, the evidence base was rather ambiguous, as some randomized and observational studies supported IVUS guided bare metal stent insertion in terms of reducing rates of restenosis and clinically driven target lesion revascularisation whereas others demonstrated no such benefit. As there is an additional cost and learning curve with IVUS, it has become difficult to justify its routine use. We present here a contemporary argument for the resurgence of IVUS optimized stent insertion. We also highlight deficiencies in previously adopted IVUS optimization criteria, which were based on distal and proximal lumen sizes. The new criteria proposed are based on vessel size at different segments of the stented area and therefore take advantage of vessel remodeling. The availability of high pressure, non-compliant balloons have made attainment of these new optimization targets possible without increasing the risk of complications. We hope to demonstrate this statement with the completion of the angiographically versus IVUS optimization (AVIO) study that soon will be initiated.

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.

Evaluation of patients for pulmonary endarterectomy

Chronic thromboembolic obstruction of the pulmonary vascular bed has been increasingly recognized as a treatable form of pulmonary hypertension, with surgery referred to as a pulmonary endarterectomy. Careful evaluation of patients with pulmonary hypertension and proper selection of those with surgically accessible, chronic thromboembolic disease are critical determinants for a successful outcome from this operation. This article describes the clinical presentation, appropriate evaluation, and an approach to surgical selection for patients with chronic thromboembolic pulmonary hypertension.

Case report: Optimizing intraoperative detection of pulmonary embolism using contrast-enhanced echocardiography

PURPOSE

Perioperative pulmonary embolism (PE) is associated with significant morbidity and mortality. Intraoperatively, the clinical management of patients with PE can be enhanced by the use of transesophageal echocardiography (TEE) to visualize emboli, assess pulmonary artery (PA) anatomy, and monitor the function of the right ventricle. However, the sensitivity of intraoperative TEE to detect thromboemboli is reported to be below 50%. In this report, we describe the use of contrast-enhanced TEE (CE-TEE) to improve the visualization of PE.

CLINICAL FEATURES

A 44-yr-old female with chronic thrombo-embolic pulmonary hypertension was scheduled for pulmonary thromboendarterectomy. The precardiopulmonary bypass TEE exam demonstrated signs of PA obstruction and right ventricle dysfunction, but the borders of the thrombus in the right PA were only minimally visualized. Perflutren lipid microspheres, composed of octafluoropropane encapsulated in an outer lipid shell, were injected as a 0.3 mL iv bolus, while visualizing the right PA with harmonic ultrasound imaging. The CE-TEE image clearly visualized a large mobile thrombus along with a distinct pattern consistent with pulmonary flow obstruction. The postcardiopulmonary bypass CE-TEE confirmed thrombus evacuation and absence of PA flow abnormalities.

CONCLUSION

Contrast-enhanced-TEE may decrease operator dependency and increase the sensitivity necessary to detect central, surgically accessible PE.

Adjunctive Balloon Postdilatation after Stent Deployment: Is It Still Necessary with Drug-Eluting Stents?

Deployment of bare metal stents (BMS) with current stent delivery systems is often associated with suboptimal stent expansion. Adjunctive postdilatation with noncompliant balloons has improved stent expansion with BMS and has been associated with less need for target vessel revascularization (TVR). Drug-eluting stents (DES) have proven highly effective in reducing restenosis and TVR and are now being used in the great majority of percutaneous coronary interventions. Because of the very low rates of TVR with DES, many operators have felt that postdilatation may no longer be necessary. In this review, we present data showing that stent expansion of DES (like BMS) using current stent delivery systems is frequently suboptimal. Furthermore, smaller mimimal stent area (MSA) and stent underexpansion following deployment of DES are strong predictors of stent thrombosis and TVR. Adjunctive postdilatation with noncompliant balloons can increase MSA and decrease the frequency of suboptimal stent deployment and potentially can reduce the frequency of stent thrombosis and TVR. Despite the lack of evidence from randomized clinical trials, we believe the observational data support the use of adjunctive balloon postdilatation following deployment of DES in the great majority of patients.

Application, feasibility, and efficacy of a combined intravascular ultrasound and stent delivery system: results from a prospective multicenter trial

BACKGROUND

Intravascular ultrasound (IVUS) is the reference method for in vivo assessment of vessel dimensions and coronary plaque composition, which can influence device selection as well as stent sizing.

OBJECTIVES

The objective of this prospective multicenter-study was to test the application, safety, and feasibility of a new combined IVUS and stent delivery system.

METHODS

A total of 32 patients with planned direct stent implantation under IVUS guidance were included in the study. Procedural as well as angiographical and IVUS characteristics of the stent implantation with the combined IVUS and stent delivery system were assessed and compared to a historical control cohort where IVUS-guided stenting was performed with a separate IVUS catheter.

RESULTS

Direct stent placement was successfully performed in all patients and no malfunctions of the system were noted. A post-interventional IVUS assessment was possible in 27 (87%) of the 31 patients. The IVUS information led to a change in therapeutic strategy in 16 (50%) of the 32 patients. In the study group, both the procedural time and the amount of contrast dye were significantly lower than in the historical IVUS-guided stenting control group. A clinical 12-month follow-up revealed a 89% event-free survival and a target vessel revascularization rate of 7%.

CONCLUSION

The use of a combined IVUS and stent delivery device is safe, easy to handle, and can provide helpful additional information to guide a percutaneous coronary interventions procedure. Beyond angiography, these informations had significant impact on the interventional strategy in these patients, which resulted in a low rate of major adverse cardiac events. The concept of combining IVUS information and a stent delivery system may be increasingly attractive with evolving imaging modalities like virtual histology or a combination with drug-eluting stents.

Clinical and angiographic outcomes after overdilatation of undersized sirolimus-eluting stents with largely oversized balloons: an observational study

The purpose of this study was to assess the safety and effectiveness of sirolimus-eluting stent (SES) postdilatation with largely oversized balloons. We evaluated the clinical outcome of 68 consecutive patients enrolled in the Rapamycin-Eluting Stent Evaluated at Rotterdam Cardiology Hospital (RESEARCH) registry who underwent percutaneous coronary intervention with SES implantation and further postdilatation with balloons > 1 mm larger than the stent nominal size. Angiographic follow-up was either scheduled for selected subgroups or clinically driven. Overall, 75 lesions were treated. The procedure was successful in 98.5% of the cases. One patient (1.5%) underwent emergency coronary bypass surgery for acute vessel occlusion. During 10.1 +/- 1.7 months of follow-up, three patients (4.5%) died, one (1.5%) had acute myocardial infarction, and four (6%) had target vessel revascularization. At angiographic follow-up, loss index was 0.13 +/- 0.34 and restenosis rate was 7.7%. Although not routinely recommended in every patient, SES postdilatation with largely oversized balloons appears a safe and effective strategy for selected patients.

Chronic thromboembolic pulmonary hypertension

During the past 2 decades, there has been a steady rise in the number of patients with chronic thromboembolic pulmonary hypertension (CTEPH) undergoing surgery and in the number of programs worldwide dedicated to the diagnosis and management of this patient population. This article discusses the natural history and clinical presentation of CTEPH, the evaluation of patients for pulmonary thromboendarterectomy, and the outcomes following surgery, along with a brief review of the procedure as performed at the University of California, San Diego.

Management of chronic obstructive pulmonary disease in the elderly

Chronic obstructive pulmonary disease (COPD), a leading cause of death and disability in the elderly, is frequently unrecognized or misinterpreted as heart disease. Comorbidity plays a primary role, both as a determinant of health status and as a prognostic marker in older populations with COPD. Multidimensional assessment tailored to the distinctive needs of respiratory patients and thus including selected respiratory function indexes, is mandatory for proper staging COPD and monitoring of its course and response to therapy. In stable COPD, a mix of pharmacological and non-pharmacological measures may improve health, but only by stopping smoking and, in the event of respiratory insufficiency, applying continuous oxygen therapy can the progression of the disease be delayed and life expectancy prolonged. In exacerbated COPD, age per se is a negative prognostic marker and, while many very old patients can successfully recover, they will experience some decline in personal independence. Thus, older patients with COPD should ideally be the object of a continuum of care throughout all the stages of their disease, in order to minimize the decline in personal independence and worsening health. In this perspective, COPD patients qualify as optimal candidates for dedicated programs of continuous geriatric care.

Impact of intravascular ultrasound-guided stenting on long-term clinical outcome: a meta-analysis of available studies comparing intravascular ultrasound-guided and angiographically guided stenting

To date, only a few studies have compared the clinical efficacy of intracoronary ultrasound (IVUS)-guided to angiographically guided stenting. Furthermore, it is not yet known whether the lower restenosis rate shown with the former strategy would translate into a substantial clinical advantage. Therefore, the aim of the present investigation was to improve the level of evidence of these studies by means of a formal meta-analysis. Nine studies were considered suitable for analysis. Odds ratios (ORs) were calculated for 6-month clinical follow-up. Primary endpoint was a composite of death and nonfatal myocardial infarction (MI), as considered in every single study. Secondary endpoints were major adverse cardiac events (MACEs), according to single study definition, the individual cardiac events, as well as several pre- and postprocedure and follow-up angiographic parameters. Overall, 2,972 patients were included. At 6 months, the OR for death and nonfatal MI was 1.13 (95% CI = 0.79-1.61; P = 0.5) for patients with IVUS-guided stenting. However, patients with IVUS-guided stenting had less target vessel revascularizations (OR = 0.62; 95% CI = 0.49-0.78; P = 0.00003) and MACEs (OR = 0.79; 95% CI = 0.64-0.98; P = 0.03) compared to angiographically guided stenting. In addition, subjects treated with IVUS-guided stenting had significantly less binary restenosis (OR = 0.75; 95% CI = 0.60-0.94; P = 0.01). The present meta-analysis demonstrates that IVUS-guided stenting implantation has a neutral effect on long-term death and nonfatal MI compared to an angiographic optimization. However, IVUS-guided stenting significantly lowers 6-month angiographic restenosis and target vessel revascularizations. Whether these benefits could be very helpful when dealing with lesions at high risk for restenosis is still an issue.

Is adjunctive balloon postdilatation necessary after coronary stent deployment? Final results from the POSTIT trial

Early-generation balloon-expandable stents required postdilatation with noncompliant balloons at high pressure to optimize stent deployment. The need for adjunctive balloon postdilatation with modern stent delivery systems is unknown. Patients undergoing elective stenting were randomized to Boston Scientific NIR, Guidant Tri-Star/Tetra, and Medtronic AVE S670 stents. The primary endpoint was optimum stent deployment defined as a minimal stent diameter (MSD) >/= 90% of the average reference lumen diameter assessed by intravascular ultrasound (IVUS) performed immediately following stent deployment. If, by operator assessment, the primary endpoint was not achieved with the stent delivery system, adjunctive postdilatation with noncompliant balloons was performed. Of 256 patients with IVUS studies adequate for core laboratory analysis, only 29% achieved optimum stent deployment with the stent delivery system. None of the baseline clinical or angiographic variables predicted optimum stent deployment. Of the procedural variables, the type of stent and nominal stent size were not predictors, but higher deployment pressures were associated with a higher frequency of optimum stent deployment (< 12 atm 14% vs. >/= 12 atm 36%; P = 0.007). The inability to achieve optimum stent deployment was not due to undersizing the stent delivery balloon, but rather to an inability of the stent delivery balloon to expand fully the stent to nominal size. In patients who underwent postdilatation, the frequency of achieving optimum stent deployment increased from 21% to 42%, minimal stent area increased from 6.6 +/- 2.2 to 7.8 +/- 2.3 mm(2), and MSD increased from 2.6 +/- 0.5 to 2.8 +/- 0.4 mm. These data stress the continued need for adjunctive balloon postdilatation with modern stent delivery systems. Cathet Cardiovasc Intervent 2003;59:184-192.

A new intracoronary measurement catheter, MetriCath, compared to intravascular ultrasound and quantitative coronary angiography in a stented porcine coronary model

The purpose of this study was to compare measurements by MetriCath to intravascular ultrasound (IVUS) and quantitative coronary angiography (QCA). The MetriCath system consists of a low-pressure (200 mm Hg) balloon catheter connected to a pressure transducer and infusion pump linked to a computer that records pressure-volume curves. Cross-sectional area of blood vessels is obtained directly from the unrestrained and in-stent pressure-volume measurements. We compared stent cross-sectional area measurements by MetriCath, IVUS, and QCA in a porcine stented coronary artery model. Comparison of area measurements in 14 stents showed no significant differences between the three methods (P = 0.66). On average, values differed 0.37 +/- 0.60 mm(2) between MetriCath and QCA, 0.13 +/- 0.55 mm(2) between MetriCath and IVUS, and 0.22 +/- 0.80 mm(2) between IVUS and QCA. This corresponds to 6.2% +/- 10%, 3.0% +/- 9.0%, and 3.1% +/- 12.9% relative difference from the average of two corresponding measurements. Linear regression analysis showed excellent correlation between measurements (r = 0.99 for all comparisons). The differences in in-stent area measurements between MetriCath and both QCA and IVUS were small. Considering the ease and rapidity of obtaining MetriCath results, this technique may form an alternative to the others in evaluating stent expansion. Based on these findings, clinical evaluation seems warranted.

Impact of morphologic characteristics of central pulmonary thromboemboli in massive pulmonary embolism

STUDY OBJECTIVE

To assess the impact of morphologically different central pulmonary artery thromboemboli in patients with massive pulmonary emboli (MPEs) on short-term outcome.

DESIGN

A prospective registry of consecutive patients.

SETTING

An 11-bed closed medical ICU at a 860-bed community general hospital

PATIENTS

Forty-seven patients with shock or hypotension due to MPE and central pulmonary thromboemboli detected by transesophageal echocardiography who were treated with thrombolysis between January 1994 and April 2000.

PROCEDURES

Patients were divided into two groups according to the following characteristics of the detected thromboemboli: group 1, thrombi with one or more long, mobile parts; and group 2, immobile thrombi. Right heart catheterization was performed.

RESULTS

The incidence of both types of thromboemboli was comparable. Groups 1 and 2 showed no differences in demographic data, risk factors for pulmonary embolism, length of preceding clinical symptoms, percentage of patients in shock, hemodynamic variables, serum lactate levels on hospital admission, and treatment. Seven fatal cases due to obstructive shock and right heart failure were present in group 2, but none were present in group 1 (7 of 23 patients vs 0 of 24 patients, respectively; p < 0.05). At 12 h, the cardiac index was lower in group 2 than in group 1 (2.6 +/- 1.0 vs 3.1 +/- 0.9 L/min/m(2), respectively; p < 0.05), and the central venous pressure (15.0 +/- 6.2 vs 12.5 +/- 3.7 mm Hg, respectively; p < 0.05) and total pulmonary resistance (12.9 +/- 5.9 vs 8.6 +/- 2.7 mm Hg/L/min/m(2), respectively; p < 0.001) were higher in group 2 compared to group 1. On hospital admission, inclusion in group 2 (p < 0.03; hazard ratio, 9.53; 95% confidence interval [CI], 1.19 to 76.47) and preexisting chronic medical or neurologic disease (p < 0.01; hazard ratio, 16.4; 95% CI, 1.97 to 136.3) were independent predictors of 30-day mortality.

CONCLUSION

On hospital admission, morphology of the thromboemboli and the presence of pre-existing chronic medical or neurologic disease are independent predictors of 30-day mortality. Patients with immobile central pulmonary thromboemboli have a worse short-term outcome than those with mobile central pulmonary thromboemboli.

Pulmonary hypertension in patients with chronic obstructive pulmonary disease: recent advances in pathophysiology and management

In patients with chronic obstructive pulmonary disease (COPD), pulmonary hypertension (PH) is associated with a worse prognosis. Recently, information has been increasing concerning the cellular and molecular aspects of the pathophysiology of PH in COPD. The most striking finding is the role of vascular endothelial cells and endogenous mediators released by these cells. Endothelial cell-dependent relaxation is impaired in COPD patients with PH. Moreover, vascular remodelling in these patients is mainly responsible for irreversible PH in advanced COPD. Smoking cessation will slow down the progression of the disease process and may prevent the development of PH in COPD. The timing of initiation of long-term oxygen therapy is important for the effective management of PH in COPD. Research on therapeutic agents for the effective treatment of PH is still needed in the management aspect of patients with COPD. This review focuses on the recent advances in our understanding of the pathophysiology and treatment of PH in COPD.

Diffuse in-stent restenosis

Stent restenosis, especially the diffuse pattern, has developed into a significant clinical and economical problem. It has been estimated that up to 250,000 patients developed in-stent restenosis in 2,000 alone, two thirds of them can be expected to have diffuse in-stent restenosis, which is difficult to treat because of high recurrence rates. None of the conventionally available interventional treatment modalities provides optimal long-term results. Intravascular radiation therapy is currently the only effective percutaneous therapy for combating in-stent restenosis. Late thrombotic complications have largely been eliminated by extended antiplatelet regimens. Geographical miss, a major reason for recurrence of in-stent restenosis after brachytherapy, can be reduced by an improved radiation technique. The first preliminary data on drug-eluting stents, showing only minimal neointimal proliferation at 6-month postimplantation, could represent a major breakthrough in the quest to solve restenosis.

Chronic thromboembolic pulmonary hypertension

Remarkable advances have occurred over the past 2 decades in the diagnostic approach, surgical management, and postoperative care of patients afflicted with chronic thromboembolic pulmonary hypertension. Despite these advances, a great deal needs to be achieved if the morbidity and mortality of the disease process are to be reduced further. First, the preliminary insights that have been achieved into the natural history of the disease must be defined further. The level of pulmonary hypertension encountered in most patients with chronic thromboembolic pulmonary hypertension at the time of initial clinical recognition cannot be reached on an acute basis. Gradual hemodynamic progression, therefore, must occur over time. The basis for this progression, why it occurs in certain patients and not others, following an acute thromboembolic event and why it seems to occur over months in certain patients and over decades in others, remain entirely speculative. It is possible that the overall extent of central pulmonary vascular obstruction represents the primary pathophysiologic determinant of disease progression. Given the lack of correlation between the degree of central thromboembolic obstruction and hemodynamic impairment in certain patients, however, it is also possible that other factors, such as the circulating vasoconstrictors, the development of a hypertensive pulmonary arteriopathy, an individual genetic predisposition to pulmonary hypertension, or the compensatory adaptations of the right ventricle, contribute to the extent and rate of disease progression. By identifying and sequentially evaluating patients with persistent pulmonary vascular obstruction or pulmonary hypertension following an acute thromboembolic event, valuable insights into the natural history of thromboembolic pulmonary hypertension and other variants of pulmonary hypertension might be achieved. It is also important to recognize that the development of chronic thromboembolic pulmonary hypertension represents a failure in the long-term management or follow-up surveillance of those with documented acute thromboembolic disease. Recent insights into the recurrent nature of acute thromboembolic disease and its potential for only partial resolution in a number of afflicted individuals suggest that a repeat perfusion scan and, if abnormal, an echocardiogram be performed at the time of anticipated discontinuation of anticoagulation in patients with documented pulmonary embolic disease. Although the cost-effectiveness of this approach has been questioned in the past, recent data suggest that doing so would help identify that subset of patients with unresolved embolism, provide additional information regarding the optimal duration of anticoagulation, and provide a new baseline study for patients in whom anticoagulation is discontinued and who subsequently present with suspected embolic recurrence. Improved diagnostic techniques are also necessary if the mortal risk of thromboendarterectomy is to be reduced. Even in the setting of a broad experiential base, prognostic uncertainty exists in approximately 10% of patients before operative intervention. Because many of these patients will benefit from the procedure, and because many are ineligible for transplantation for reason of age or other restriction, it has been the authors' practice to offer surgery to these patients, although at an assumed higher risk. To not do so would be to deny a potentially lifesaving procedure to many who would benefit and who might be left without an effective therapeutic alternative. The ability to better define the group of patients who will not benefit from surgery, however, would spare those patients the morbid and mortal risks of the procedure and provide a basis for the investigation of other therapeutic alternatives such as pulmonary vasodilating agents. Finally, this patient population offers a unique opportunity to enhance understanding of the pathophysiologic mechanisms involved in acute lung injury. The population involved is uniform, the predisposing event is consistent, the time of onset is predictable, and, compared with other populations at risk for acute lung injury, the presence of confounding variables is negligible. It also provides a unique opportunity to evaluate pharmacologic interventions designed to prevent or diminish the occurrence of acute lung injury and postoperative management strategies designed to minimize its impact.

Experimental evaluation of a short transitional edge protection balloon for intracoronary stent deployment

The purpose of this study was to determine if balloon injury to the adjacent arterial wall during intracoronary stent deployment influences late in-stent neointimal formation. Stent design and deployment techniques are considered important factors in determining acute and long-term success with intracoronary stenting. Experimental and clinical studies support that the extent of neointimal formation and the probability for restenosis are influenced by the magnitude of arterial trauma induced with stenting. Nineteen 18-mm-long balloon-expandable stainless steel stents (MULTI-LINK Duet) were implanted at a 1:1 stent-to-artery ratio in the coronary arteries of swine with a conventional noncompliant balloon (n = 10) or a novel noncompliant balloon with short tapered shoulders to prevent edge dissection (n = 9). Quantitative coronary angiography and histology were used to evaluate balloon and artery interactions and the chronic vascular responses to the stents. Nineteen stents were implanted in the coronary arteries of seven swines at an inflation pressure of 14 atm using a standard noncompliant (n = 10) or a unique short transitional edge protection (n = 9) balloon. Histologic analysis at 28 days demonstrated balloon-associated barotrauma in 13 of 20 (65%) of adjacent nonstented arterial segments with the conventional balloon and only 3 of 18 (17%) of the adjacent nonstented arterial segments with the short transition edge protection balloon (P = 0.022). In-stent neointimal area and % stenosis correlated with the severity of peristent arterial injury (r = 0.43, P = 0.01). In-stent vessel injury scores were similar for stents with peristent injury (1.0+/-0.3) versus stents without peristent injury (1.0+/-0.03, P = 0.73). In-stent neointimal area and % stenosis were greater for stents with peristent injury (2.36+/-0.74 mm(2), 32%+/-9%) as compared to stents without peristent injury (1.39+/-0.70 mm(2), 20%+/-10%, P = 0.01). Arterial wall injury adjacent to a stent after high-pressure deployment contributes to late in-stent neointimal hyperplasia in this model. These experimental data suggest that further study is warranted to refine stent implantation techniques and that modifications of balloon shape or material may be useful to optimize stent deployment and reduce arterial trauma.