To the Editors:
INTRODUCTION
People with HIV (PWH) have elevated risks for heart failure (HF),1,2 which can manifest during various stages of HIV infection. Among PWH, a lower nadir CD4 count (<200 cells/mm3) is associated with a higher HF risk.3 However, less is known regarding cardiac dysfunction in PWH with severe CD4 lymphopenia starting antiretroviral therapy (ART); such data are derived primarily from historical case series of AIDS cardiomyopathy and preceded detailed hemodynamic and tissue characterization on cardiac imaging.4–6 Of interest are PWH with immune reconstitution inflammatory syndrome (IRIS), who experience a dramatic increase in systemic and tissue inflammation after initiation of ART. Up to one-third of US PWH, and a larger proportion worldwide, present with CD4 counts <200 and are at a heightened risk for IRIS7; therefore, there is clinical relevance in determining factors underlying cardiac dysfunction in lymphopenic patients initiating ART.
Given the dearth of modern data on cardiac function in PWH presenting with severe immunosuppression, we investigated associations of immunologic and inflammatory markers with cardiac function and intracardiac pressures in a cohort of PWH presenting with severe lymphopenia.
METHODS
Study Design
We performed a nested study within a prospective cohort of PWH at the National Institute of Allergy and Infectious Diseases (NIAID) HIV clinic between January 1, 2007, and July 24, 2019. The cohort included patients from the following 2 clinical protocols: (1) Immune reconstitution syndrome in HIV-infected patients taking ART (IRIS, NCT00286767) and (2) positron emission tomography Imaging and Lymph Node Assessment of IRIS in People with AIDS (PANDORA, NCT02147405). Inclusion criteria included age ≥18 years, documented HIV infection, CD4 count <100 cells/μL, no previous ART, and willingness to start therapy. Exclusion criteria were pregnancy and active substance use. All study participants signed informed consent and were followed prospectively from ART initiation (week 0) to weeks 2, 4, 8, 12, 24, 36, and 48. ART regimens and initiation time were chosen according to local treatment guidelines and clinicians’ preferences. The clinical team at the study site identified IRIS events as previously published.8,9 For this analysis, data elements derived from the IRIS and PANDORA studies were paired with echocardiographic data from the subset of IRIS and PANDORA participants who had clinically indicated echocardiography performed in the course of clinical care. The primary analyses focused on echocardiographic parameters after ART initiation and included participants from IRIS and PANDORA with echocardiography performed within 100 days after ART initiation. Secondarily, we investigated associations of pre-ART immune markers with pre-ART cardiac markers in participants from IRIS and PANDORA who had echocardiography performed within 14 days before initiating ART.
Laboratory Evaluations
Plasma HIV viral load, CD4, and CD8 T-cell counts were performed using standardized assays at enrollment (baseline/week 0—before ART), after ART initiation (week 2), and within 10 days of the first echo (up to 100 days post-ART). Batched cryopreserved plasma samples from participants at baseline and week 2 were tested using electrochemiluminescence (Meso Scale Discovery, Rockville, MD) for C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α); enzyme-linked fluorescent assay on a VIDAS instrument (bioMerieux, Marcy-l’Etoile, France) for D-dimer levels; and enzyme-linked immunosorbent assay (R&D Systems, Minneapolis, MN) for soluble tissue factor and soluble CD14 (sCD14).
Echocardiographic Measurements
Left ventricular ejection fraction (LVEF), right ventricular systolic pressure (RVSP), diastolic mitral inflow velocities, left ventricular end diastolic dimension, and left atrial end systolic diameter were measured. RVSP is a validated correlate of pulmonary arterial pressure,10 which is a marker of cardiac congestion and worsening HF.11 For the primary analyses, we used the first available data after starting ART [median time to echo 18 days [interquartile range (IQR) 7, 42]. For secondary analyses, data were derived from the latest pre-ART echocardiogram.
Statistical Analysis
Wilcoxon rank-sum and Fischer exact tests were used to compare demographics, ART categories, echo parameters, immunologic markers, and inflammatory markers. We measured associations of immune cell markers at baseline, week 2, and at the time of first post-ART echo as well as inflammatory markers at baseline and week 2, with echo measures post-ART. Secondary analyses compared pre-ART laboratory markers and echocardiographic data. Correlations were measured using Pearson’s correlation coefficients. To account for multiple testing of correlations, Bonferroni correction was used (significance threshold of P < 0.0007). For the between-group comparisons, P < 0.05 threshold was used. The coprimary echo end points measured were LVEF and RVSP, both of which were log transformed for the analyses.
RESULTS
There were 91 participants with echocardiography performed within 100 days after ART initiation, of a total of 270 total IRIS and PANDORA participants. Seventy-three participants in IRIS and PANDORA had echocardiography performed within 14 days before ART initiation and were eligible for secondary analyses. Of note, only 13 study participants had both pre-ART and post-ART echocardiography, precluding adequately powered longitudinal comparisons of pre-ART to post-ART changes in echocardiographic parameters. The mean age of the group analyzed for primary analyses (N = 91) was 40.7 ± 11.4 years, 59% were men, and 75% were non-Hispanic Blacks. The baseline median CD4 count was 19 T cells/mm3 (IQR, 8–44), and the median viral load was 193,184 copies/mL (IQR, 88,911–456,875). ART class prevalence was as follows: 53% on nonnucleoside reverse transcriptase inhibitors, 32% on protease inhibitors, and 56% on integrase inhibitors. Thirty-one of the included patients (34.1%) developed IRIS, 19% of the overall cohort had clinical HF at baseline, 13% had Kaposi sarcoma, 7% had Cryptococcus, 12% had active tuberculosis, and 33% had pneumocystis pneumonia.
Patients with vs. without IRIS had no differences in demographics, baseline HF, ART type, or opportunistic infections (Table 1). There was no difference in echo parameters or immune cell counts and viral load at baseline, week 2, or time of echo. Patients with IRIS had higher baseline levels of D-dimer and TNF-α and higher levels of D-dimer, TNF-α, CRP, and IL-6 at 2 weeks (Table 1). Of the 31 patients, 7 patients (22.6%) in the IRIS group had adjudicated HF vs. 10 of the 60 patients in the non-IRIS group (16.7%; P = 0.69). Patients with vs. without baseline HF had no significant demographic differences and no difference in baseline immune cell counts or viral load but had higher baseline IL-6 levels [median = 4.3 pg/mL (IQR, 3.6–8.5)] compared with those without {median = 2.4 pg/mL [(IQR, 1.7–4.6), P = 0.035]}.
TABLE 1.
Associations of Demographics, Clinical Variables, and Laboratory Markers With Cardiac Function and the Presence of IRIS
| Right Ventricle Systolic Pressureb |
Left Ventricle Ejection Fractionb |
IRIS absent (n = 60) | IRIS Present (n = 31) | P | |||
|---|---|---|---|---|---|---|---|
| Statistica | P | Statistica | P | ||||
| Age, yr (mean 6 SD) | 0.22 | 0.145 | −0.01 | 0.921 | 41.92 ± 11.92 | 38.45 ± 10.14 | 0.171 |
| Male sex (%) | 43 (71.7) | 16 (51.6) | 0.095 | ||||
| BMI, kg/m2 (mean 6 SD) | 0.08 | 0.647 | −0.02 | 0.922 | 22.44 ± 4.83 | 24.65 ± 9.52 | 0.327 |
| Race-ethnicity (%) | 0.299 | ||||||
| Hispanic | 3 (10.3) | 4 (18.2) | |||||
| Non-Hispanic Black | 21 (72.4) | 17 (77.3) | |||||
| Non-Hispanic White | 1 (3.4) 4 (13.8) | 1 (4.5) 0 (0.0) | |||||
| Heart failure (%) | 10 (16.7) | 7 (22.6) | 0.688 | ||||
| NNRTI (%) | 30 (50.0) | 18 (58.1) | 0.611 | ||||
| PI (%) | 20 (33.3) | 9 (29.0) | 0.857 | ||||
| Integrase (%) | 34 (56.7) | 17 (54.8) | 1 | ||||
| Comorbid infections | |||||||
| Active TB (%) | 4 (8.2) | 5 (20.0) | 0.272 | ||||
| Pneumocystis pneumonia (%) | 17 (35.4) | 6 (27.3) | 0.69 | ||||
| Left ventricular ejection fraction, % (mean ± SD) | 52.52 (16.61) | 53.79 (16.53) | 0.796 | ||||
| Right ventricular systolic pressure, mm Hg (mean ± SD) | 29.81 (10.15) | 29.60 (11.24) | 0.948 | ||||
| Mitral E/A ratio (mean ± SD) | 1.16 (0.61) | 1.39 (0.92) | 0.352 | ||||
| LA systolic diameter, mm (mean ± SD) | 34.00 (7.30) | 35.16 (6.01) | 0.575 | ||||
| LV end diastolic diameter, mm (mean ± SD) | 49.04 (8.73) | 47.93 (5.90) | 0.676 | ||||
| Baseline markers | |||||||
| CD4+ T cells/mL (median [IQR])b | −0.03 | 0.848 | −0.02 | 0.903 | 17.00 [8.00–41.00] | 28.00 [8.00–47.50] | 0.544 |
| CD8+ T cells/mL (median [IQR])b | 0.27 | 0.067 | −0.13 | 0.387 | 373.00 [245.50–496.50] | 393.00 [257.50–795.50] | 0.306 |
| CD4/CD8 ratio (median [IQR])b | −0.52 | 0.0003 | 0.23 | 0.136 | 0.05 [0.03–0.10] | 0.05 [0.03–0.08] | 0.76 |
| HIV viral load, copies/mL (median [IQR])b | −0.07 | 0.656 | 0.04 | 0.810 | 156,623 [55,177–400,265] | 242,793 [120,962–500,000] | 0.105 |
| d-dimer, ng/mL (median [IQR])b | 0.13 | 0.394 | 0.03 | 0.865 | 1373.30 [856–2674] | 2400 [1,434–3546] | 0.027 |
| CRP, ng/mL (median [IQR])b | 0.30 | 0.042 | 0.04 | 0.774 | 5200 [1,223–17,432] | 5869 [2,748–18,415] | 0.388 |
| IL-6, pg/mL (median [IQR])c | −0.15 | 0.332 | 0.17 | 0.274 | 2.35 [1.59–5.00] | 3.41 [2.13–5.93] | 0.105 |
| TNF-α, pg/mL (median [IQR])c | −0.16 | 0.301 | −0.10 | 0.539 | 9.08 [6.54–14.05] | 13.26 [8.30–18.52] | 0.026 |
| Soluble CD14, ng/mL (median [IQR]) | 0.11 | 0.481 | 0.02 | 0.903 | 2,610,237 [2,021,491–3,024,374] | 2,505,229 [2,197,651–3,339,005] | 0.519 |
| Tissue factor, pg/mL (median [IQR]) | 0.17 | 0.292 | −0.23 | 0.155 | 80.55 [67.71–105.42] | 94.15 [65.02–113.42] | 0.874 |
| Week 2 markers | |||||||
| Change in CD4 from baseline to | −0.18 | 0.240 | 0.15 | 0.329 | 24 [7–60] | 57 [10–106] | 0.087 |
| week 2 (median [IQR]) | |||||||
| CD4+ T cells/mL (median [IQR])b | 0.03 | 0.824 | −0.10 | 0.494 | 53.5 [23–100.5] | 82 [30–153] | 0.11 |
| CD8+ T cells/mL (median [IQR])b | 0.16 | 0.295 | −0.01 | 0.935 | 417 [280–653] | 492 [193–793] | 0.983 |
| CD4/CD8 ratio (median [IQR])b | −0.15 | 0.326 | 0.09 | 0.564 | 0.10 [0.06–0.22] | 0.16 [0.09–0.30] | 0.148 |
| HIV viral load, copies/mL (median [IQR])b | −0.35 | 0.017 | 0.23 | 0.127 | 458 [233–1513] | 699 [299–2910] | 0.28 |
| D-dimer, ng/mL (median [IQR])b | 0.07 | 0.689 | −0.03 | 0.864 | 969 [629–1836] | 2354 [797–3920] | 0.009 |
| CRP, ng/mL (median [IQR])b | 0.06 | 0.691 | −0.06 | 0.695 | 6564 [1396–30,722] | 32,795 [9,343–78,900] | 0.001 |
| IL-6, pg/mL (median [IQR])c | −0.14 | 0.381 | 0.00 | 1.000 | 2.32 [1.22–5.13] | 7.47 [2.63–16.52] | <0.001 |
| TNF-α, pg/mL (median [IQR])c | −0.10 | 0.550 | 0.02 | 0.918 | 7.51 [4.76–13.08] | 16.34 [8.42–25.66] | 0.001 |
| Soluble CD14, ng/mL (median [IQR]) | 0.09 | 0.576 | −0.04 | 0.813 | 2,257,003 [1,813,221–2,852,754] | 2,742,045 [2,185,802–3,116,137] | 0.086 |
| Tissue factor, pg/mL (median [IQR]) | 0.16 | 0.332 | −0.30 | 0.067 | 84.16 [61.92–96.43] | 86.23 [59.68–97.65] | 0.96 |
| Markers closest in time to echocardiogram (within 10 days) | |||||||
| CD4+ T cells/mL (median [IQR])b | −0.26 | 0.084 | 0.13 | 0.368 | 30.50 [11.00–57.50] | 36 [14.00–73.50] | 0.412 |
| CD8+ T cells/mL (median [IQR])b | 0.29 | 0.047 | −0.10 | 0.491 | 371 [246.75–531.75] | 455 [291.50–866.00] | 0.197 |
| CD4/CD8 ratio (median [IQR])b | −0.52 | 0.0002 | 0.23 | 0.120 | 0.08 [0.03–0.15] | 0.09 [0.03–0.20] | 0.815 |
| HIV viral load, copies/mL (median [IQR])b | 0.25 | 0.096 | −0.24 | 0.102 | 83,448 [1,825–194,913] | 109,246.00 [623–300,598] | 0.903 |
Bold P<0.05 significant for pairwise comparisons; Bonferroni-corrected P<0.0007 significant for multiple comparisons.
Pearson correlation coefficients for continuous variable and Beta coefficients from linear regression for categorical variables, with P value calculated using the Wald test.
Log transformation performed because of nonnormal distribution of the variable.
Square-root transformation performed because of nonnormal distribution of the variable.
BMI, Body-mass index; LA, left atrial; LV, left ventricular; NNRTI, nonnucleoside reverse transcriptase inhibitor; PI, protease inhibitor; TB, tuberculosis.
In the overall study population included in primary analyses, a lower CD4/CD8 ratio at baseline and time of echo (post-ART) was associated with higher RVSP (Table 1). HIV viral load at baseline, week 2, and near the time of echo did not have a significant association with LVEF. The inflammatory markers at baseline or week 2 and the change in CD4 count from baseline to week 2 were not associated with LVEF or RVSP. There were no significant interactions between immune or inflammatory markers and sex with respect to echocardiographic parameters. In secondary analyses of associations of pre-ART laboratory and pre-ART echocardiographic measures (N = 73 with pre-ART echocardiography), higher CRP levels were associated with higher RVSP (r = 0.46, P = 0.00004) and a lower CD4/CD8 ratio was associated with higher RVSP (r = −0.39, P = 0.0009), although this did not meet significance after Bonferroni correction.
DISCUSSION
We investigated associations of immune and inflammatory markers with cardiac function among PWH who presented with advanced AIDS in the modern ART era and were followed prospectively after ART initiation. This provided the opportunity to understand the relationship between immune activation that occurs in patients with advanced AIDS before and after ART initiation, including those with IRIS and myocardial dysfunction that may contribute to a downstream risk of HF observed in PWH.
We found that lower CD4/CD8 ratios pre-ART and after ART initiation were associated with higher RVSP on post-ART echocardiography.11 This finding is consistent with recent studies from the broader HIV population that demonstrate clear associations of lower CD4 counts with a higher HF risk.2,3 Whether HIV-related CD4 lymphopenia itself is a cause of cardiac dysfunction and HF or a proxy marker of other factors (virologic, inflammatory, or otherwise) that lead to HF merits investigation in future mechanistic and clinical studies. Furthermore, it is possible that relative depletion of CD4 compared with CD8 lymphocytes and a related shift toward amplified CD8-predominant immune activation may predispose to heightened inflammation (as observed in studies of immune-progressed HIV) and HF.1,12–18 Yet, interestingly, although pre-ART CRP levels were associated with higher pre-ART RVSP, the presence of IRIS or inflammatory markers at baseline and week 2 was not associated with post-ART LVEF or RVSP. This may reflect the limited sample size, early intervention with anti-inflammatory therapies, or other residual confounding and warrants further investigation.
The limitations of our study include the sample size and possible selection bias because echocardiography was performed as clinically indicated. Nevertheless, this represents the largest study investigating cardiac function among PWH presenting with advanced AIDS in the modern ART era. Our finding that, among PWH presenting with very low CD4 counts, a lower CD4/CD8 ratio is associated with higher RVSP warrants further study and may have implications for HIV-associated HF.
ACKNOWLEDGMENTS
The authors thank all study participants and the staff in outpatient clinic 8 and the NIAID inpatient ward at the NIH clinical center for their tireless contributions to excellent clinical care.
American Heart Association (Fellow to Faculty Award AHA FTF31200010, PI: M.J.F.); National Institutes of Health Centers for AIDS Research Administrative Supplement (NIAID P30 AI117943, PI: M.J.F.), Intramural research program of NIAID, National Institutes of Health.
Footnotes
The authors have no funding or conflicts of interest to disclose.
REFERENCES
- 1.Feinstein MJ, Steverson AB, Ning H, et al. Adjudicated heart failure in HIV-infected and uninfected men and women. J Am Heart Assoc. 2018;7:e009985. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Freiberg MS, Chang CH, Skanderson M, et al. Association between HIV infection and the risk of heart failure with reduced ejection fraction and preserved ejection fraction in the antiretroviral therapy era: results from the Veterans Aging Cohort Study. JAMA Cardiol. 2017;2:536–546. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Steverson AB, Pawlowski AE, Schneider D, et al. Clinical characteristics of HIV-infected patients with adjudicated heart failure. Eur J Prev Cardiol. 2017;24:1746–1758. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Acierno LJ. Cardiac complications in acquired immunodeficiency syndrome (AIDS): a review. J Am Coll Cardiol. 1989;13:1144–1154. [DOI] [PubMed] [Google Scholar]
- 5.Levy WS, Simon GL, Rios JC, et al. Prevalence of cardiac abnormalities in human immunodeficiency virus infection. Am J Cardiol. 1989;63:86–89. [DOI] [PubMed] [Google Scholar]
- 6.De Castro S, d’Amati G, Gallo P, et al. Frequency of development of acute global left ventricular dysfunction in human immunodeficiency virus infection. J Am Coll Cardiol. 1994;24:1018–1024. [DOI] [PubMed] [Google Scholar]
- 7.Buchacz K, Armon C, Palella FJ, et al. CD4 cell counts at HIV diagnosis among HIV outpatient study participants, 2000–2009. AIDS Res Treat. 2012;2012:869841. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8.Sereti I, Sheikh V, Shaffer D, et al. Prospective international study of incidence and predictors of immune reconstitution inflammatory syndrome and death in people with HIV and severe lymphopenia. Clin Infect Dis. 2020;71:652–660. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9.Hammoud DA, Boulougoura A, Papadakis GZ, et al. Increased metabolic activity on 18F-fluorodeoxyglucose positron emission tomography-computed tomography in human immunodeficiency virus-associated immune reconstitution inflammatory syndrome. Clin Infect Dis. 2019;68:229–238. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 10.Taleb M, Khuder S, Tinkel J, et al. The diagnostic accuracy of Doppler echocardiography in assessment of pulmonary artery systolic pressure: a meta-analysis. Echocardiography. 2013;30:258–265. [DOI] [PubMed] [Google Scholar]
- 11.Rosenkranz S, Gibbs JS, Wachter R, et al. Left ventricular heart failure and pulmonary hypertension. Eur Heart J. 2016;37:942–954. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12.Kaplan RC, Sinclair E, Landay AL, et al. T cell activation and senescence predict subclinical carotid artery disease in HIV-infected women. J Infect Dis. 2011;203:452–463. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 13.Longenecker CT, Funderburg NT, Jiang Y, et al. Markers of inflammation and CD8 T-cell activation, but not monocyte activation, are associated with subclinical carotid artery disease in HIV-infected individuals. HIV Med. 2013;14:385–390. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14.Mattingly AS, Unsal AB, Purdy JB, et al. T-cell activation and E-selectin are associated with coronary plaque in HIV-infected young adults. Pediatr Infect Dis J. 2017;36:63–65. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 15.Prasada S, Rivera A, Nishtala A, et al. Differential associations of chronic inflammatory Diseases with incident heart failure. J Am Coll Cardiol Heart Fail. 2020;8:489–498. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16.Feinstein MJ, Hsue PY, Benjamin LA, et al. Characteristics, prevention, and management of cardiovascular disease in people living with HIV: a scientific statement from the American heart association. Circulation. 2019;140: e98–e124. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 17.Lisco A, Wong CS, Lage SL, et al. Identification of rare HIV-1-infected patients with extreme CD4+ T cell decline despite ART-mediated viral suppression. JCI Insight. 2019; 4:e127113. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 18.Nou E, Lo J, Grinspoon SK. Inflammation, immune activation, and cardiovascular disease in HIV. AIDS. 2016;30:1495–1509. [DOI] [PMC free article] [PubMed] [Google Scholar]
