Clinically significant incidental findings among human immunodeficiency virus-infected men during computed tomography for determination of coronary artery calcium

Incidental Findings on Coronary Computed Tomography Angiography in Human Immunodeficiency Virus (HIV)-Positive and HIV-Negative Persons

Background

Incidental findings on coronary computed tomography angiography (CCTA) have a great impact on the benefits and costs of testing for cardiovascular disease. The number of incidental findings might be increased in human immunodeficiency virus (HIV)-positive individuals compared with the general population. Data are limited regarding the association between incidental findings and HIV infection.

Methods

We assessed the prevalence and factors associated with incidental findings among HIV-positive and HIV-negative participants ≥45 years undergoing CCTA. Logistic regression was performed to evaluate the factors associated with incidental findings in the HIV-positive and HIV-negative groups. For the analysis of the HIV effect, a propensity score-matched dataset of HIV-positive/HIV-negative participants was used.

Results

We included 553 participants, 341 with and 212 without HIV infection. Incidental findings were observed in 291 of 553 (53%) patients. In 42 of 553 (7.6%) participants, an incidental finding resulted in additional workup. A malignancy was diagnosed in 2 persons. In the HIV-positive group, age (1.31 per 5 years, 1.10–1.56) and smoking (2.29, 1.43–3.70) were associated with incidental findings; in the HIV-negative group, age (1.26, 1.01–1.59) and a CAC score >0 (2.08, 1.09–4.02) were associated with incidental findings. Human immunodeficiency virus seropositivity did not affect the risk of incidental findings.

Conclusions

Incidental findings were highly prevalent among HIV-positive and HIV-negative persons. Human immunodeficiency virus infection was not associated with an increased risk of incidental findings.

Lung cancer in persons with HIV

PURPOSE OF REVIEW

Lung cancer is emerging as a leading cause of death in HIV-infected persons. This review will discuss the latest scientific evidence regarding the mechanisms driving lung cancer risk in HIV infection, the clinical presentation of lung cancer in HIV-infected persons and recent data regarding the outcomes, treatment and prevention of lung cancer in this group.

RECENT FINDINGS

Increased risk of lung cancer in HIV-infected persons is primarily due to higher smoking rates, but emerging evidence also implicates immunosuppression and inflammatory processes. Lung cancer outcomes may be worse in HIV-infected persons in the antiretroviral era, but this may stem, in part, from treatment disparities. Early detection of lung cancer using chest computed tomography (CT) is being increasingly adopted for smokers in the general population, and recent studies suggest that it may be safe and efficacious in HIV-infected smokers.

SUMMARY

Lung cancer is an important complication associated with chronic HIV infection. It is associated with unique HIV-related causal mechanisms, and may be associated with worse outcomes in some HIV-infected persons. Smoking cessation and early cancer detection with chest CT are likely to benefit HIV-infected smokers.

Incidental findings on chest computed tomography are common and linked to inflammation in HIV-infected adults

BACKGROUND

Chest imaging is performed for a variety of reasons in HIV-infected adults. There are limited data on the prevalence of incidental findings, progression of these findings over time and the relationship with inflammation in antiretroviral therapy (ART)-treated HIV-infected adults.

METHODS

This study utilized data from a randomized clinical trial of rosuvastatin in HIV-infected adults on ART. Incidental findings were reported from chest computed tomography (CT) scans obtained for coronary artery calcium score at entry, week 48 and 96. Markers of immune activation and inflammation were measured concurrently. Poisson regression and generalized estimating equations were used.

RESULTS

A total of 147 participants were enrolled. Median age was 46 years, 78% were male, 68% African American and 63% current smokers. At baseline, 57% of participants had at least one incidental lung finding (ILF) and four additional participants had at least one ILF by week 96. At baseline, older age, current smoking, lower nadir CD4⁺ T-cell count and low-density lipoprotein and higher lipoprotein-associated phospholipase A2 (Lp-PLA2) were independently associated with having a greater number of ILFs. In the longitudinal analyses, older age, lower nadir CD4⁺ T-cell count and higher baseline soluble tumour necrosis factor α-receptor I (sTNF-RI) were independently associated with having a greater number of ILFs over 96 weeks.

CONCLUSIONS

Over half of participants had at least one incidental finding on chest CT. Beyond traditional factors of older age and smoking, lower nadir CD4⁺ T-cell count and higher markers of inflammation were associated with having a greater number of ILFs in HIV-infected adults on ART.

Lung Malignancies in HIV Infection

Pulmonary malignancies are a major source of morbidity and mortality in HIV-infected persons. Non-AIDS-defining lung cancers (mostly non-small cell lung cancers) are now a leading cause of cancer death among HIV-infected persons. HIV-associated factors appear to affect the risk of lung cancer and may adversely impact cancer treatment and outcomes. HIV infection also may modify the potential harms and benefits of lung cancer screening with computed tomography. AIDS-defining lung malignancies include pulmonary Kaposi sarcoma and pulmonary lymphoma, both of which are less prevalent with widespread adoption of antiretroviral therapy.

Clinically significant extra-cardiac findings in asymptomatic HIV-positive men undergoing cardiac magnetic resonance imaging

Increased research-based imaging has led to an increase in clinically significant extra-cardiac findings. HIV patients are at increased risk of having polypathology at a younger age; therefore, it may be hypothesised that they would have more incidental findings on imaging. We reviewed the magnetic resonance imaging results of 169 HIV-positive and 40 HIV-negative, clinically well volunteers undergoing cardiac magnetic resonance imaging scanning to assess the prevalence of subclinical cardiac pathology. This sub-study assessed the prevalence of clinically significant extra-cardiac findings. Associated risk factors were assessed and clinical follow-up and outcome were ascertained. Of the HIV-positive study group, 12/169 (7.1%) vs. 1/40 (2.5%) control patients had a clinically significant extra-cardiac finding which warranted further radiological or clinical intervention (p = 0.28). A total of three out of 169 (1.1%) were highly clinically significant findings. On logistic regression analysis, age was the only significant contributing factor (p = 0.049); no HIV-associated factors were found to be significant. The prevalence of clinically significant extra-cardiac findings of 7.1% in this HIV-positive cohort is comparable to the prevalence found in previous studies carried out on an older, sicker general population. This highlights the need for planning for unexpected outcomes and also the high rate of clinically significant findings in a seemingly well HIV-positive population.

Findings in asymptomatic HIV-infected patients undergoing chest computed tomography testing: implications for lung cancer screening

BACKGROUND

HIV-infected persons have a two-fold to five-fold increased unadjusted risk of lung cancer. In the National Lung Screening Trial (NLST), computed tomography (CT) screening was associated with a reduction in lung cancer mortality among high-risk smokers. These results may not generalize to HIV-infected persons, particularly if they are more likely to have false-positive chest CT findings.

METHODS

We utilized data including standardized chest CT scans from 160 HIV infected and 139 uninfected Veterans enrolled between 2009 and 2012 in the multicenter Examinations of HIV Associated Lung Emphysema (EXHALE) Study. Abnormal CT findings were abstracted from clinical interpretations of the scans and classified as positive by NLST criteria vs. other findings. Clinical evaluations and diagnoses that ensued were abstracted from the medical record.

RESULTS

There was no significant difference by HIV in the proportion of CT scans classified as positive by NLST criteria (29% of HIV infected and 24% of HIV uninfected, P=0.3). However, HIV-infected participants with CD4 cell counts less than 200 cells/μl had significantly higher odds of positive scans, a finding that persisted in multivariable analysis. Evaluations triggered by abnormal CT scans were also similar in HIV-infected and uninfected participants (all P>0.05).

CONCLUSION

HIV status was not associated with an increased risk of abnormal findings on CT or increased rates of follow-up testing in clinically stable outpatients with CD4 cell count more than 200. These data reflect favorably on the balance of benefits and harms associated with lung cancer screening for HIV-infected smokers with less severe immunodeficiency.