Pathological findings of HIV-associated cardiovascular disease

Multimodality Imaging in HIV-Associated Cardiovascular Complications: A Comprehensive Review

Human immunodeficiency virus (HIV) infection is a leading cause of mortality and morbidity worldwide. The introduction of antiretroviral therapy (ART) has significantly reduced the risk of developing acquired immune deficiency syndrome and increased life expectancy, approaching that of the general population. However, people living with HIV have a substantially increased risk of cardiovascular diseases despite long-term viral suppression using ART. HIV-associated cardiovascular complications encompass a broad spectrum of diseases that involve the myocardium, pericardium, coronary arteries, valves, and systemic and pulmonary vasculature. Traditional risk stratification tools do not accurately predict cardiovascular risk in this population. Multimodality imaging plays an essential role in the evaluation of various HIV-related cardiovascular complications. Here, we emphasize the role of multimodality imaging in establishing the diagnosis and aetiopathogenesis of various cardiovascular manifestations related to chronic HIV disease. This review also provides a critical appraisal of contemporary data and illustrative cases.

Clinical Application of Cardiac Magnetic Resonance in ART-Treated AIDS Males with Short Disease Duration

Cardiac complications are common in antiretroviral therapy-treated (ART-treated) acquired immune deficiency syndrome (AIDS) patients, and the incidence increases with age. Myocardial injury in ART-treated AIDS patients with a relatively longer disease duration has been evaluated. However, there is no relevant study on whether patients with a short AIDS duration have cardiac dysfunction. Thirty-seven ART-treated males with AIDS and eighteen healthy controls (HCs) were prospectively included for CMR scanning. Clinical data and laboratory examination results were collected. The ART-treated males with AIDS did not have significantly reduced biventricular ejection fraction, myocardial edema, or late gadolinium enhancement. Compared with the HCs, the biventricular volume parameters and left ventricle myocardial strain indices in ART-treated males with AIDS were not significantly reduced (all p > 0.05). ART-treated males with AIDS were divided into subgroups according to their CD4+ T-cell counts (<350 cells/μL and ≥350 cells/μL) and duration of disease (1−12 months, 13−24 months, and 25−36 months). There was no significant decrease in left or right ventricular volume parameters or myocardial strain indices among the subgroups (all p > 0.05). In Pearson correlation analysis, CD4+ T-cell counts were not significantly correlated with biventricular volume parameters or left ventricular myocardial strain indices. In conclusion, ART-treated males with AIDS receiving ART therapy with a short disease duration (less than 3 years) might not develop obvious cardiac dysfunction as evaluated by routine CMR, so it is reasonable to appropriately extend the interval between cardiovascular follow-ups to more than 3 years.

HIV Tat Protein Induces Myocardial Fibrosis Through TGF-β1-CTGF Signaling Cascade: A Potential Mechanism of HIV Infection-Related Cardiac Manifestations

Human immunodeficiency virus (HIV) infection is a risk factor of cardiovascular diseases (CVDs). HIV-infected patients exhibit cardiac dysfunction coupled with cardiac fibrosis. However, the reason why HIV could induce cardiac fibrosis remains largely unexplored. HIV-1 trans-activator of transcription (Tat) protein is a regulatory protein, which plays a critical role in the pathogenesis of various HIV-related complications. In the present study, recombinant Tat was administered to mouse myocardium or neonatal mouse cardiac fibroblasts in different doses. Hematoxylin-eosin and Masson's trichrome staining were performed to observe the histological changes of mice myocardial tissues. EdU staining and MTS assay were used to evaluate the proliferation and viability of neonatal mouse cardiac fibroblasts, respectively. Real-time PCR and western blot analysis were used to detect CTGF, TGF-β1, and collagen I mRNA and protein expression levels, respectively. The results showed that Tat promoted the occurrence of myocardial fibrosis in mice. Also, we found that Tat increased the proliferative ability and the viability of neonatal mouse cardiac fibroblasts. The protein and mRNA expression levels of TGF-β1 and CTGF were significantly upregulated both in Tat-treated mouse myocardium and neonatal mouse cardiac fibroblasts. However, co-administration of TGF-β inhibitor abrogated the enhanced expression of collagen I induced by Tat in neonatal mouse cardiac fibroblasts. In conclusion, Tat contributes to HIV-related cardiac fibrosis through enhanced TGF-β1-CTGF signaling cascade.

Primary Cardiac Lymphoma: Three Case Reports and a Review of the Literature

Primary cardiac lymphoma (PCL) is a rare entity that comprises only 1-2% of all cardiac tumors. Due to their scarcity and variable clinical presentation, early diagnosis is challenging. In this series, three cases of PCL from a single institution are described, which highlight the spectrum of presenting features and emphasize common principles. In the first case, a 73-year-old male who presented with dyspnea was found to have a 12.1 cm mass in the right ventricle. Biopsy via cardiac catheterization revealed diffuse large B cell lymphoma (DLBCL). He was treated with chemoimmunotherapy and survived for two months. The second case describes a 55-year-old female who presented with chest pain. Imaging revealed a 3.1 cm right atrial mass and bilateral pleural effusions, with cytology from the latter demonstrating DLBCL. She was lost to follow up after three cycles of chemoimmunotherapy. In the last case, an 80-year-old female presented with weakness. A 4.0 cm mass was discovered in the right atrium and the patient expired shortly after admission. Autopsy confirmed the diagnosis of DLBCL. These case summaries are followed by a review of the clinical presentation, diagnostic approach, and treatment outcomes of PCL.

More Than Just an Ulcer: A Case of HIV-Associated Iliac Aneurysms Presenting With a Leg Ulcer

The incidence of symptomatic vasculitis in human immunodeficiency virus (HIV)-infected patients is approximately 1%, and it commonly presents as arterial occlusive disease or aneurysmal disease. Early diagnosis of vascular complications in those patients is essential; however, it is extremely challenging. Iliac aneurysms are usually silent, and because of their deep location, detection of these aneurysms is typically difficult. Therefore, they always continue to be asymptomatic until rupture unless they are discovered incidentally on a radiological investigation for an irrelative condition. We present the case of a 61-year-old HIV-positive man with bilateral iliac aneurysms and total coronary artery occlusion presenting with a leg ulcer.

Echocardiography in Patients with HIV Infection

PURPOSE OF REVIEW

This review aims to outline the important echocardiographic findings observed in patients with human immunodeficiency virus (HIV) infection in the current era of treatment.

RECENT FINDINGS

HIV infection has a wide spectrum of cardiac manifestations. Myocardial and pericardial involvement were the primary cardiac manifestations in HIV patients early during the epidemic in the developed countries. In the current era of effective antiretroviral therapy, the spectrum has shifted to metabolic abnormalities (hyperlipidemia, hypertension, etc.), accelerated atherosclerotic disease, and cardiac sequelae related to these abnormalities. Dramatic improvement in life expectancy of patients with HIV infection has resulted in a shift in the developed nations in the spectrum of cardiac manifestations, currently dominated by diastolic dysfunction and coronary artery disease. Echocardiography and advanced echocardiographic techniques play a major role in diagnosis and screening of HIV patients with underlying cardiovascular abnormalities.

The role of cardiac imaging in the management of non-ischemic cardiovascular diseases in human immunodeficiency virus infection

Infection with human immunodeficiency virus (HIV) has become the pandemic of the new century. About 36.9 million people are living with HIV worldwide. The introduction of antiretroviral therapy in 1996 has dramatically changed the global landscape of HIV care, resulting in significantly improved survival and changing HIV to a chronic disease. With near-normal life expectancy, contemporary cardiac care faces multiple challenges of cardiovascular diseases, disorders specific to HIV/AIDS, and those related to aging and higher prevalence of traditional risk factors. Non-ischemic cardiovascular diseases are major components of cardiovascular morbidity and mortality in HIV/AIDS. Non-invasive cardiac imaging plays a pivotal role in the management of these diseases. This review summarizes the non-ischemic presentation of the HIV cardiovascular spectrum focusing on the role of cardiac imaging in the management of these disorders.

The role of HIV Tat protein in HIV-related cardiovascular diseases

The human immunodeficiency virus (HIV) is a major global public health issue. HIV-related cardiovascular disease remains a leading cause of morbidity and mortality in HIV positive patients. HIV Tat is a regulatory protein encoded by tat gene of HIV-1, which not only promotes the transcription of HIV, but it is also involved in the pathogenesis of HIV-related complications. This review is aimed at summarizing the current understanding of Tat in HIV-related cardiovascular diseases.

Transforming growth factor-β1-mediated cardiac fibrosis: potential role in HIV and HIV/antiretroviral therapy-linked cardiovascular disease

HIV infection elevates the incidence of cardiovascular disease (CVD) independent of traditional risk factors. Autopsy series document cardiac inflammation and endomyocardial fibrosis in the HIV+ treatment naïve, and gadolinium enhancement magnetic resonance imaging has identified prominent myocardial fibrosis in the majority of HIV+ individuals despite use of suppressive antiretroviral therapies (ART). The extent of such disease may correlate with specific ART regimens. For example, HIV-infected patients receiving ritonavir (RTV)-boosted protease inhibitors have the highest prevalence of CVD, and RTV-exposed rodents exhibit cardiac dysfunction coupled with cardiac and vascular fibrosis, independent of RTV-mediated lipid alterations. We recently showed that platelet transforming growth factor (TGF)-β1 is a key contributor to cardiac fibrosis in murine models. We hypothesize that in the HIV+/ART naïve, cardiac fibrosis is a consequence of proinflammatory cytokine and/or ART-linked platelet activation with release of TGF-β1. Resultant TGF-β1/Smad signaling would promote collagen synthesis and organ fibrosis. We document these changes in a pilot immunohistochemical evaluation of cardiac tissue from two ART-naive pediatric AIDS patients. In terms of ART, we showed that RTV inhibits immunoproteasome degradation of TRAF6, a nuclear adapter signaling molecule critical to the regulation of proinflammatory cytokine signaling pathways involved in osteoclast differentiation and accelerated osteoporosis. We now present a model illustrating how RTV could similarly amplify TGF-β1 signaling in the promotion of cardiac fibrosis and accelerated CVD. Supportive clinical data correlate RTV use with elevation of NT-proBNP, a biomarker for CVD. We discuss potential interventions involving intrinsic modulators of inflammation and collagen degradation, including carbon monoxide-based therapeutics.

Multimodality imaging of cardiothoracic lymphoma

Lymphoma is the most common hematologic malignancy and represents approximately 5.3% of all cancers. The World Health Organization published a revised classification scheme in 2008 that groups lymphomas by cell type and molecular, cytogenetic, and phenotypic characteristics. Most lymphomas affect the thorax at some stage during the course of the disease. Affected structures within the chest may include the lungs, mediastinum, pleura, and chest wall, and lymphomas may originate from these sites as primary malignancies or secondarily involve these structures after arising from other intrathoracic or extrathoracic sources. Pulmonary lymphomas are classified into one of four types: primary pulmonary lymphoma, secondary pulmonary lymphoma, acquired immunodeficiency syndrome-related lymphoma, and post-transplantation lymphoproliferative disorders. Although pulmonary lymphomas may produce a myriad of diverse findings within the lungs, specific individual features or combinations of features can be used, in combination with secondary manifestations of the disease such as involvement of the mediastinum, pleura, and chest wall, to narrow the differential diagnosis. While findings of thoracic lymphoma may be evident on chest radiography, computed tomography has traditionally been the imaging modality used to evaluate the disease and effectively demonstrates the extent of intrathoracic involvement and the presence and extent of extrathoracic spread. However, additional modalities such as magnetic resonance imaging of the thorax and (18)F-FDG PET/CT have emerged in recent years and are complementary to CT in the evaluation of patients with lymphoma. Thoracic MRI is useful in assessing vascular, cardiac, and chest wall involvement, and PET/CT is more accurate in the overall staging of lymphoma than CT and can be used to evaluate treatment response.

What a differential a virus makes: a practical approach to thoracic imaging findings in the context of HIV infection--part 2, extrapulmonary findings, chronic lung disease, and immune reconstitution syndrome

OBJECTIVE

The Centers for Disease Control and Prevention reported more than one million people with HIV infection in the United States in 2006, an increase of 11% over 3 years. Worldwide, nearly 34 million people are infected with HIV. Pulmonary disease accounts for 30-40% of acute hospitalizations of HIV-seropositive patients, underscoring the importance of understanding the range of cardiothoracic imaging findings associated with HIV infection. This article will cover extrapulmonary thoracic diseases, chronic lung diseases, and immune reconstitution inflammatory syndrome in HIV-infected patients. Our approach is focused on the radiologist's perspective by recognizing and categorizing key imaging findings to generate a differential diagnosis. The differential diagnosis can be further refined by incorporating clinical data, such as patient demographics, CD4 count, and presenting symptoms. In addition, with prolonged survival of HIV-infected patients in the era of highly active antiretroviral therapy, radiologists can also benefit from awareness of imaging features of a myriad of chronic cardiopulmonary diseases in this patient population. Finally, the change of imaging findings and clinical status in response to treatment provides important diagnostic information, such as in immune reconstitution syndrome.

CONCLUSION

Developing a practical approach to key cardiothoracic imaging findings in HIV-infected patients will aid the radiologist in generating a clinically relevant differential diagnosis and interpretation, thereby improving patient care.

HIV-related cardiac complications: CT and MRI findings

OBJECTIVE

Cardiovascular complications in patients with HIV infection include myocardial, endocardial, pericardial, and vascular diseases. The complications are caused by the HIV infection itself, opportunistic infections, HIV-related tumors, and the side effects of highly active antiretroviral therapy. The article reviews the CT and MRI findings suggestive of HIV-related cardiovascular diseases.

CONCLUSION

The cardiovascular complications of HIV infection frequently overlap, making the diagnosis difficult. CT and MRI are useful for the noninvasive evaluation of these complications.

Acute idiopathic hemorrhagic pericarditis with cardiac tamponade as the initial presentation of acquired immune deficiency syndrome

This paper presents a case of cardiac tamponade with idiopathic hemorrhagic pericarditis as the initial symptom of human immunodeficiency virus (HIV) infection. A 29-year-old male came to the emergency room with a sudden onset of dizziness. Upon arrival, he was hypotensive although not tachycardic, and his jugular venous pressure was not elevated. His chest X-rays revealed a mild cardiomegaly. Transthoracic echocardiography revealed a large amount of pericardial effusion with a diastolic collapse of the right ventricle, a dilated inferior vena cava with little change in respiration, and exaggerated respiratory variation of mitral inflow velocities, representing echocardiographic evidence of cardiac tamponade. After pericardiocentesis, his blood pressure improved to 110/70 mmHg without inotropics support. Serial 12-lead electrocardiograms during hospitalization revealed upwardly concave diffuse ST-segment elevation followed by a T-wave inversion suggestive of acute pericarditis. Pericardial fluid cytology and cultures for bacteria, mycobacteria, adenovirus, and fungus were all negative. HIV enzyme-linked immunosorbent assay (ELISA) was positive and confirmed by Western blot. The CD4 cell count was 168/mm(3). Finally, the diagnosis of cardiac tamponade due to HIV-associated hemorrhagic pericarditis was made. It was concluded that HIV infection should be considered in the diagnosis of unexplained pericardial effusion or cardiac tamponade in Korea.

Bacterial lipopolysaccharide enhances cardiac dysfunction but not retroviral replication in murine AIDS: roles of macrophage infiltration and toll-like receptor 4 expression

Cardiovascular disease is an important complication of human immunodeficiency virus/acquired immune deficiency syndrome (AIDS), but the mechanism(s) involved are poorly understood. Although co-infecting pathogens have been implicated as an important factor in AIDS progression, no studies have investigated these interactions in cardiac tissue. We recently demonstrated that the murine AIDS model (LPBM5 retroviral infection) mimics human immunodeficiency virus-related cardiac dysfunction and pathology. We tested the hypothesis that subseptic lipopolysaccharide exposure (LPS) would enhance LPBM5 progression and exacerbate cardiovascular dysfunction during murine AIDS development. LPS (5 mg/kg, Escherichia coli 0111:B4) was administered at 1, 6, and 8 weeks during LPBM5 infection, and cardiac performance was evaluated at 10 weeks using noninvasive echocardiography. LPS alone had no significant effects, whereas it amplified abnormalities in cardiac structure and function observed in murine AIDS. Cardiac dysfunction was associated with selective increases in nonfocal infiltration of CD68(+) cells and correlated with the extent of cardiac dysfunction. Retroviral progression and cardiac retroviral content remained unaltered, but cardiac toll-like receptor 4 was increased in retrovirus + LPS. We provide first-time evidence of multipathogen enhancements to retrovirus-related cardiac complications and implicate innate immune responses, not co-pathogen-induced retroviral replication, as the primary mechanism in this setting.

Cardiovascular complications of human immunodeficiency virus infection

The heart and great vessels are not the sites most frequently affected by opportunistic infections and neoplastic processes in patients with acquired immune deficiency syndrome (AIDS). However, cardiovascular complications occur in a significant number of such patients and are the immediate cause of death in some. The spectrum of cardiovascular complications of AIDS that may be depicted at imaging includes dilated cardiomyopathy, pericardial effusion, human immunodeficiency virus-associated pulmonary hypertension, endocarditis, thrombosis, embolism, vasculitis, coronary artery disease, aneurysm, and cardiac involvement in AIDS-related tumors. To aid accurate diagnosis and appropriate treatment planning, radiologists should be familiar with the imaging appearance of each of these complications.

What a Cardiologist Needs to Know About Patients With Human Immunodeficiency Virus Infection

Patient case: A 48-year-old man with human immunodeficiency virus (HIV) infection developed chronic chest pain that started after a bout of pneumonia. He has hypertension and has smoked cigarettes in the past. His current medications include Kaletra and Combivir. His total cholesterol was 331 mg/L, his HDL cholesterol was 27 mg/L, his triglycerides were 935 mg/L, and his LDL cholesterol could not be calculated. How should this patient be evaluated and managed?

AIDS-related vasculopathy: evidence for oxidative and inflammatory pathways in murine and human AIDS

Increased life expectancy of human immunodeficiency virus (HIV)-positive patients has led to evidence of complications apparently not directly related to immunodeficiency or opportunistic infection, including increased cardiovascular risk. We tested the hypothesis that vascular dysfunction occurs in the murine acquired immune deficiency syndrome (AIDS) model and evaluated potential mechanisms in murine AIDS tissues and relevant human HIV/AIDS vascular tissues. We also investigated endothelial activation and/or endothelial protein nitration and their association with time-dependent vascular dysfunction. At 1 and 5 wk of murine AIDS, statistically significant decreases in KCl contractility and time-dependent contractile deficits in response to phenylephrine were observed. The maximal response (E(max)) was reduced by approximately 40% at 10 wk, and EC(50) values were significantly changed: 102 +/- 7.3 ng for control vs. 190 +/- 37 and 130 +/- 22 ng at 5 and 10 wk, respectively (P < 0.05). Endothelium-dependent relaxation to ACh was decreased (EC(50) = 120 +/- 27 and 343 +/- 94 nM for control and at 10 wk, respectively), whereas the response to an exogenous nitric oxide donor, sodium nitroprusside, remained unchanged, suggesting a specific endothelial dysfunction. Histochemical investigations of the same vascular tissues as well as corresponding coronary endothelium showed an increase in protein 3-nitrotyrosine, intercellular adhesion molecule, and nitric oxide synthase isoforms 2 and 3. These findings were corroborated in concurrent experiments in a cohort of well-cataloged human cardiac microvascular tissues. We have demonstrated, for the first time, a specific functional vasculopathy with endothelial involvement in a murine model of AIDS that was also associated with and correlated to increased oxidative stress and specific endothelial activation. This finding was echoed in a relevant population of human HIV/AIDS patients. Research into sources and intracellular targets of oxidants in this disease could provide important mechanistic insights and may reveal new therapeutic opportunities for this increasingly important cardiovascular disease state.

HIV-related cardiovascular disease and drug interactions

HIV infection is a global public health issue that is frequently associated with cardiovascular involvement. These HIV-associated cardiovascular manifestations are often clinically occult or attributed incorrectly to other non-cardiac disease processes. A heightened awareness and routine screening for cardiovascular involvement in HIV-infected patients leads to earlier detection and the hope for a reduction in associated morbidity and mortality. Left ventricular dysfunction, an independent predictor of mortality in HIV-infected patients, is the result of many causes in this population and may result in dilated cardiomyopathy and congestive heart failure in about 10% of patients. Other HIV-associated cardiovascular problems include infective endocarditis, cardiovascular malignancy, pulmonary arterial hypertension, vasculitis, pericardial effusion, premature atherosclerosis, and arrhythmias. HIV-associated cardiovascular emergencies include congestive heart failure, pulmonary edema, supraventricular and ventricular arrhythmias, endocarditis, and tamponade. Anti-infective and immunomodulatory therapies may be particularly helpful in this population to reduce associated cardiovascular disease. Highly active antiretroviral therapy may result in lipodystrophy, hyperlipidemia, truncal adiposity, and insulin resistance that can be improved by physical activity and training programs. Cardiovascular complications of therapeutic drugs in HIV-infected patients include torsade de pointes, congestive heart failure, dyslipidemia, accelerated atherosclerosis, and myocardial infarction. In summary, cardiovascular complications are important contributors to morbidity and mortality in HIV-infected patients that can be detected early in many cases and treated effectively.

Epidemiology of HIV cardiac disease

The heart is an organ frequently affected in patients with acquired immune deficiency syndrome (AIDS). Since the introduction of highly active antiretroviral therapy (HAART), a sharp decline in mortality and morbidity has been observed in human immunodeficiency virus (HIV)-infected patients. However, numerous reports of myocardial infarcts in young HIV-infected patients have raised concerns of premature coronary artery disease in this population. New risk factors for coronary heart disease such as increased insulin resistance, dyslipidemia, and lipodystrophy syndrome, which are associated with HAART, may accelerate underlying arteriosclerosis in HIV-infected patients. Data on the incidence of coronary heart disease are limited to case reports and retrospective studies. Results from ongoing, large, prospective studies will provide information on whether or not HAART may increase the incidence of myocardial infarcts and whether a drastic change in HIV therapy is warranted.