Reversible cardiac dysfunction associated with foscarnet therapy for cytomegalovirus esophagitis in an AIDS patient

Infectious and Non-infectious Etiologies of Cardiovascular Disease in Human Immunodeficiency Virus Infection

Background:

Increasing rates of HIV have been observed in women, African Americans, and Hispanics, particularly those residing in rural areas of the United States. Although cardiovascular (CV) complications in patients infected with human immunodeficiency virus (HIV) have significantly decreased following the introduction of antiretroviral therapy on a global scale, in many rural areas, residents face geographic, social, and cultural barriers that result in decreased access to care. Despite the advancements to combat the disease, many patients in these medically underserved areas are not linked to care, and fewer than half achieve viral suppression.

Methods:

Databases were systematically searched for peer-reviewed publications reporting infectious and non-infectious etiologies of cardiovascular disease in HIV-infected patients. Relevant articles cited in the retrieved publications were also reviewed for inclusion.

Results:

A variety of outcomes studies and literature reviews were included in the analysis. Relevant literature discussed the manifestations, diagnosis, treatment, and outcomes of infectious and non-infectious etiologies of cardiovascular disease in HIV-infected patients.

Conclusion:

In these medically underserved areas, it is vital that clinicians are knowledgeable in the manifestations, diagnosis, and treatment of CV complications in patients with untreated HIV. This review summarizes the epidemiology and causes of CV complications associated with untreated HIV and provide recommendations for management of these complications.

Human immunodeficiency virus & cardiovascular risk

Highly active antiretroviral therapy (HAART) significantly changed the prevalence of the cardiovascular manifestations of human immunodeficiency virus (HIV)/AIDS. In developed countries, a 30 per cent reduction in the prevalence of cardiomyopathy and pericardial effusion was observed, possibly related to a reduction of opportunistic infections and myocarditis. In developing countries, however, where the availablity of HAART is limited, and the pathogenic impact of nutritional factors is significant, a 32 per cent increase was seen in the prevalence of cardiomyopathy and related high mortality rate from congestive heart failure. Also, some HAART regimens in developed countries, especially those including protease inhibitors, may cause, in a high proportion of HIV-infected patients, a lipodystrophy syndrome that is associated with an increased risk of cardiovascular events related to a process of accelerated atherosclerosis. Careful cardiac screening is warranted for patients who are being evaluated for, or who are receiving HAART regimens, particularly for those with known underlying cardiovascular risk factors, according to the most recent clinical guidelines.

Myocardial disease in human immunodeficiency virus (HIV) infection: a review

Heart muscle disease is the most important cardiovascular manifestation of HIV infection and is likely to become even more prevalent as HIV infected patients live longer. This may present as myocarditis, dilated cardiomyopathy or isolated left or right ventricular dysfunction. Myocardial involvement in HIV infection is multifactorial and may arise as a result of myocardial invasion with HIV itself, opportunistic infections, viral infections, autoimmune response to viral infection, drug-related cardiac toxicity, nutritional deficiencies, and prolonged immunosuppression. Both adults and children are affected with severity ranging from incidental microscopic inflammatory findings at autopsy to clinically significant cardiac disease with chronic cardiac dysfunction. It is associated with a poor prognosis, and results in symptomatic heart failure in up to 5% of HIV patients. Clinical pathological studies from the pre-HAART era show a 30% prevalence of cardiomyopathy in patients with AIDS. The introduction of highly active antiretroviral therapy (HAART) regimens has substantially modified the course of HIV disease by lengthening survival and improving quality of life of HIV-infected patients. There is also good evidence that HAART significantly reduces the incidence of cardiovascular manifestations of HIV infection. By preventing opportunistic infections and reducing the incidence of myocarditis, HAART regimens have reduced the prevalence of HIV-associated cardiomyopathy by almost 7-fold from the pre-HAART era. HAART is however only available to a minority of HIV infected individuals in most areas of the world and studies from the pre-HAART period still apply. In this review, the aetiopathogenesis and presentation of HIV related myocardial disease were reviewed and measures taken to improve survival discussed.

Pathogenesis of HIV-associated heart disease

As longevity increases in HIV-infected individuals after the introduction of highly active antiretroviral therapy regimens, long-term effects such as cardiovascular disease and, more specifically, symptomatic heart failure are emerging as leading health issues. In the present review article, we discuss HIV-associated cardiovascular disease, focusing on etiopathogenetic mechanisms that may play a role in diagnosis, management, and therapy of HIV-associated heart failure in the highly active antiretroviral therapy era.

Pathogenesis of HIV-associated cardiomyopathy

Reviews and studies published before the introduction of highly active antiretroviral therapy (HAART) regimens have tracked the incidence and course of human immunodeficiency virus (HIV) infection in relation to cardiac illness in both children and adults. HAART regimens have significantly modified the course of HIV disease, with longer survival rates and improvement of life quality in HIV+ subjects expected. However, early data raised concerns about HAART's being associated with an increase in both peripheral and coronary arterial diseases. A variety of potential etiologies have been postulated in HIV-related heart disease, including myocardial infection with HIV itself, opportunistic infections, viral infections, autoimmune response to viral infection, drug-related cardiotoxicity, nutritional deficiencies, and prolonged immunosuppression. In this review article we discuss HIV-associated cardiovascular complications, focusing on pathogenetic mechanisms that may play a role in diagnosis, management, and therapy of these complications.

Drugs and cardiotoxicity in HIV and AIDS

The advent of potent antiretroviral drugs in recent years has had an impressive impact on mortality and disease progression in HIV-infected patients, so that issues related to long-term effects of drugs are of growing importance. Hyperlipidemia, hyperglycemia, and lipodystrophy are increasingly described adverse effects of highly active antiretroviral therapy (HAART), in particular when protease inhibitors are used. Hyperlipidemia is strikingly associated with the use of most available protease inhibitors, with an estimated prevalence of up to 50%. Because of the short observation period and the small number of cardiovascular events, epidemiological evidence for an increased risk of coronary heart disease in HIV-infected patients treated with HAART is not adequate at present; however, it is likely that shortly more data will accumulate to quantify this risk. Before starting HAART and during treatment it is reasonable to evaluate all patients for traditional coronary risk factors, including lipid profile. Among the drugs that are currently used in HIV+ patients, antibacterials, antifungals, psychotropic drugs and anti-histamines have been associated with QT prolongation or torsade de pointe, a life-threatening ventricular arrhythmia. Among the risk factors that may precipitate an asymptomatic electrocardiographic abnormality into a dangerous arrhythmia is the concomitant use of drugs that share the CYP3A metabolic pathway. Since most protease inhibitors are potent inhibitors of CYP3A, clinicians should be aware of this potentially dangerous effect of HAART. Anthracyclines are potent cytotoxic antibiotics that have been widely used for the treatment of HIV-related neoplasms. Their cardiotoxicity is well known, ranging from benign and reversible arrhythmias to progressive severe cardiomyopathy. The increased survival and quality of life of HIV+ patients emphasize the importance of a high awareness of adverse drug-related cardiac effects.

Cardiomyopathy in AIDS: a pathophysiological perspective

This report addresses issues of pathogenesis, pathophysiology, and epidemiology of an increasingly prevalent cardiomyopathy in acquired immunodeficiency syndrome (AIDS). As patient survival increases with more effective antiretroviral therapy, cardiomyopathy in AIDS will become more apparent. The interactions of cellular and organism factors in AIDS and their relationships to the development of cardiomyopathy are reviewed herein. Amongst the factors addressed in this review are: (1) comorbid conditions found with AIDS, (2) the role of inflammatory heart disease and cytokines in the development of AIDS cardiomyopathy, (3) the pathogenetic role of vascular cells and myocardial cells in the development of cardiomyopathy, (4) the role of myocardial retroviral infection in AIDS, and (5) the impact of toxicity from antiretroviral therapy on the development of cardiomyopathy. Because it is possible that more than 1 of these factors is present in a given patient inflicted with AIDS, a multifactorial pathogenesis in AIDS cardiomyopathy must be considered.

Medical management of HIV disease in children

Significant advances have been made in the understanding of the pathophysiology of HIV infection since the beginning of the epidemic. This knowledge has translated into the development of new therapies for HIV and opportunistic infections, laboratory advances in monitoring viral and immune status, and a better understanding of factors affecting patient outcome. Concomitantly, significant progress has been made in the medical management of children with HIV infection in the past 5 years. The number of children reported with AIDS in the United States is decreasing, and efforts are shifting from caring for children with advanced immunosuppression and severe opportunistic infections to early HAART, maintenance of the immune system, and prevention of opportunistic infections. Primary care physicians are now more involved and informed in the care of HIV-infected patients. Although published data are limited, physicians who have been working with this population have observed a dramatic improvement in the quality of life and length of survival of these patients. Unfortunately, this progress is not shared by developing countries where resources are minimal and antiretroviral agents are commonly unavailable. Although efforts to develop a vaccine to prevent HIV infection are ongoing, progress has been slow. Education and awareness continue to be the most powerful weapons against HIV.

Drug-induced heart failure

Heart failure is a clinical syndrome that is predominantly caused by cardiovascular disorders such as coronary heart disease and hypertension. However, several classes of drugs may induce heart failure in patients without concurrent cardiovascular disease or may precipitate the occurrence of heart failure in patients with preexisting left ventricular impairment. We reviewed the literature on drug-induced heart failure, using the MEDLINE database and lateral references. Successively, we discuss the potential role in the occurrence of heart failure of cytostatics, immunomodulating drugs, antidepressants, calcium channel blocking agents, nonsteroidal anti-inflammatory drugs, antiarrhythmics, beta-adrenoceptor blocking agents, anesthetics and some miscellaneous agents. Drug-induced heart failure may play a role in only a minority of the patients presenting with heart failure. Nevertheless, drug-induced heart failure should be regarded as a potentially preventable cause of heart failure, although sometimes other priorities do not offer therapeutic alternatives (e.g., anthracycline-induced cardiomyopathy). The awareness of clinicians of potential adverse effects on cardiac performance by several classes of drugs, particularly in patients with preexisting ventricular dysfunction, may contribute to timely diagnosis and prevention of drug-induced heart failure.

Left ventricular dysfunction in human immunodeficiency virus (HIV)-infected patients

We evaluated left ventricular function by echocardiography in a prospective study that included 98 consecutive human immunodeficiency virus (HIV)-infected patients and 40 HIV-seronegative normal controls. When compared with controls, HIV patients showed increased isovolumic relaxation time (101+/-18 ms versus 71+/-10 ms; p<0.0001) and left ventricular diastolic diameters (51+/-6 mm versus 47+/-3 mm; p<0.0005), and decreased fractional shortening (31+/-6% versus 37+/-2%; p<0.0001). Diastolic dysfunction was the most frequent finding (63% of the patients). We found depressed ejection fraction in 31 (32%) patients. Only 8 (8%) patients had symptomatic congestive heart failure. Left ventricular dysfunction was not attributable to intravenous drug abuse or to therapy. It was less severe in earlier stages of the infection (fractional shortening: acquired immunodeficiency syndrome=30%+/-6%, asymptomatic HIV-seropositives 34%+/-5%; p<0.005) and in HIV-2-infected patients. Patients with opportunistic infections (all aetiologies mixed) had more frequent congestive heart failure than those without infections (16% of the patients with versus 4% of the patients without infections; p<0.05). The fact that even asymptomatic HIV-seropositives had signs of left ventricular dysfunction (fractional shortening: asymptomatic HIV-seropositives=34%+/-5%; controls=37%+/-2%; p<0.05) favours the hypothesis of the HIV being one of the causes of these abnormalities.

Limitations of fractional shortening as an index of contractility in pediatric patients infected with human immunodeficiency virus

Left ventricular fractional shortening (FS) is dependent on left ventricular preload and afterload, as well as contractility. Contractility may therefore not be accurately described by FS, especially in infants and children infected with human immunodeficiency virus (HIV), who tend to have abnormal left ventricular preload and afterload. We therefore examined the magnitude and clinical impact of the discrepancy between FS and contractility by assessment of 177 echocardiograms from 76 HIV-infected pediatric patients (median age, 1.9 years). The studies included simultaneous measurements of left ventricular FS, contractility, preload, and afterload. The correlation between contractility and FS was modest (r = 0.70; p < 0.001), and was weaker in children less than 2 years of age (r = 0.52) than in older children (r = 0.84). FS incorrectly predicted contractility in 46% of the studies; 43% with depressed FS (< 28%) had either normal (17/42) or enhanced (1/42) contractility. For 67% of echocardiograms, FS and contractility differed by > 1 SD, and for 36% the difference was > 2 SD. These differences remained after adjustment of FS for age or body surface area. Afterload was abnormal in 42% and preload in 21% of all echocardiograms. High preload predicted that FS would overestimate contractility (p = 0.002); high afterload predicted that FS would underestimate contractility (p < 0.001). The discrepancy between FS and contractility was larger among children who were younger, had more advanced HIV disease, or were not sedated during echocardiography. One third of children with congestive symptoms had normal contractility and depressed FS; the discrepancy was primarily due to loading conditions. We conclude that the high incidence of abnormal loading conditions in HIV-infected infants and children limits the usefulness of load-dependent FS for assessing contractility. Measurements of loading conditions and load-independent indexes, which more directly reflect contractility, allow a more accurate determination of myocardial status and may lead to better clinical management.

Foscarnet. A reappraisal of its antiviral activity, pharmacokinetic properties and therapeutic use in immunocompromised patients with viral infections

The DNA polymerase of human herpes viruses, including cytomegalovirus (CMV), and the reverse transcriptase of human immunodeficiency virus (HIV) are selectively inhibited in vitro by the pyrophosphate analogue foscarnet. Inhibition is reversible on withdrawal of foscarnet and additive or synergistic effects have been demonstrated in vitro with other antiviral drugs, including ganciclovir and zidovudine. Foscarnet appears to have negligible effects on host enzymes and cells. Complete or partial clinical resolution of ocular symptoms is obtained in more than 89% of patients with acquired immunodeficiency syndrome (AIDS) and CMV retinitis during foscarnet induction therapy, but relapse occurs soon after ceasing treatment. Maintenance treatment given daily can extend the period of remission considerably. Foscarnet and ganciclovir monotherapy had similar efficacy in the treatment of CMV retinitis in patients with AIDS in several studies, and have been used concomitantly in immunocompromised patients with recalcitrant CMV infections. In 1 trial, patients receiving foscarnet survived for significantly longer than those receiving ganciclovir. Foscarnet has been used successfully in the treatment of limited numbers of immunocompromised patients with CMV-associated gastrointestinal (improvement in over 67% of patients) and other infections. Aciclovir-resistant herpes simplex infections in immunocompromised patients have also been treated successfully with foscarnet. Almost 90% of a foscarnet dose is excreted in the urine. Reversible nephrotoxicity is common during foscarnet therapy, but may be reduced by dosage adjustment and adequate hydration. Anaemia, nausea and vomiting, disturbances in electrolyte levels and genital ulceration have also been associated with administration of the drug. The different tolerability profiles of foscarnet and zidovudine facilitate the use of these agents in combination in patients with AIDS and CMV infection; whereas ganciclovir, like zidovudine, is associated with dose-limiting haematological toxicity. The apparent survival benefits seen in these patients when receiving foscarnet and zidovudine (possibly linked to synergy between zidovudine and foscarnet and/or the inherent anti-HIV activity of foscarnet), appear to offer potentially important advantages for foscarnet over ganciclovir in the treatment of selected patients with AIDS and CMV infections.