Sudden cardiac death in HIV-infected patients: A contemporary review

Residual Traditional Risk in Non-Traditional Atherosclerotic Diseases

Individuals with chronic inflammatory and immune disorders are at an increased risk of atherosclerotic events and premature cardiovascular (CV) disease. Despite extensive literature exploring the relationship between "non-traditional" atherosclerotic conditions and CV risk, many aspects remain unresolved, including the underlying mechanisms promoting the "non-traditional CV risk", the development of an innovative and comprehensive CV risk assessment tool, and recommendations for tailored interventions. This review aims to evaluate the available evidence on key "non-traditional" CV risk-enhancer conditions, with a focus on assessing and managing CV risk factors. We conducted a comprehensive review of 412 original articles, narrative and systematic reviews, and meta-analyses addressing the CV risk associated with "non-traditional" atherosclerotic conditions. The analysis examined the underlying mechanisms of these relationships and identified strategies for assessing and mitigating elevated risk. A major challenge highlighted is the difficulty in quantifying the contribution of individual risk factors and disease-specific elements to CV risk. While evidence supports the cardiovascular benefits of statins beyond lipid lowering, such as pleiotropic and endothelial effects, current guidelines lack specific recommendations for the use of statins or other therapies targeting non-traditional CV risk factors. Additionally, the absence of validated cardiovascular risk scores that incorporate non-traditional risk factors hinders accurate CV risk evaluation and management. The growing prevalence of "non-traditional CV risk-enhancer conditions" underscores the need for improved awareness of CV risk assessment and management. A thorough understanding of all contributing factors, including disease-specific elements, is crucial for accurate prediction of cardiovascular disease (CVD) risk. This represents an essential foundation for informed decision-making in primary and secondary prevention. We advocate for future research to focus on developing innovative, disease-specific CV risk assessment tools that incorporate non-traditional risk factors, recognizing this as a promising avenue for translational and clinical outcome research.

A Comprehensive Review of the Manifestation of Cardiovascular Diseases in HIV Patients

The increasing lifespan of people living with HIV (PLWH) due to advancements in antiretroviral therapy (ART) has shifted mortality patterns from AIDS-related to non-AIDS-related causes, notably cardiovascular diseases (CVDs). This review investigates how HIV and ART contribute to vascular endothelial dysfunction, myocardial fibrosis, and hypercoagulation, which significantly exacerbate cardiovascular risk. Mechanistic insights include chronic inflammation and immune dysregulation due to persistent HIV infection and ART-specific effects such as protease inhibitors causing dyslipidemia and zidovudine inducing mitochondrial toxicity leading to cardiomyopathy. ART, while lifesaving, has been implicated in promoting subclinical atherosclerosis and increasing the risk of acute myocardial infarction, further highlighting the need for tailored approaches. The manuscript addresses pressing obstacles, including disparities in healthcare access and the lack of standardized cardiovascular screening guidelines specific to PLWH. It emphasizes the integration of advanced imaging techniques and emerging biomarkers, such as coronary artery calcium scoring and soluble ST2, to detect early subclinical cardiovascular abnormalities. The review also identifies challenges in ART selection to balance virologic control and cardiovascular safety. What sets this review apart is its holistic and detailed approach to the intersection of HIV and cardiovascular health. It not only elucidates complex pathophysiological mechanisms but also offers actionable insights into how current clinical guidelines fall short. This manuscript underscores the urgency of implementing proactive cardiovascular screening protocols tailored for PLWH and refining ART regimens to mitigate CVD risks. By addressing these gaps, this work aims to expand our understanding of HIV-related cardiovascular manifestations and provide a foundation for targeted interventions, thereby improving long-term health outcomes for PLWH. This comprehensive perspective is poised to transform clinical practice by fostering greater awareness among physicians and encouraging the development of more effective strategies for managing cardiovascular risks in the HIV population.

Out-of-Hospital Cardiac Arrest in Individuals With Human Immunodeficiency Virus: A Nationwide Population-Based Cohort Study

BACKGROUND

Little data exist on the risk and outcomes of out-of-hospital cardiac arrest (OHCA) in people with HIV (PWH). We aimed to describe OHCA in PWH as compared with the general population in terms of incidence, characteristics, and survival.

METHODS

This nationwide study assessed all individuals aged 18-85 years between 2001 and 2019 in Denmark. The cumulative incidence of OHCA was computed using cause-specific Cox models accounting for competing risk of death.

RESULTS

Among 6 565 309 individuals, 6 925 (median age: 36; interquartile range [IQR]: 28-44 y; 74% males) were infected at some point with HIV. The incidence of OHCA was 149 (95% CI: 123-180)/100 000 person-years in PWH versus 64 (95% CI: 64-65)/100 000 person-years in people without HIV (P < .001). Age at the time of cardiac arrest was 52 (IQR: 44-61) years in PWH versus 69 (IQR: 59-77) years in individuals without HIV (P < .001). In a multivariable model adjusted for age, sex, hypertension, diabetes, heart failure, ischemic heart disease, atrial fibrillation, chronic obstructive pulmonary disease, cancer, and renal failure, PWH had a 2-fold higher risk of OHCA (hazard ratio: 2.84; 95% CI: 2.36-3.43; P < .001). Thirty-day mortality (89% vs 88%; P = .80) was comparable to individuals without HIV.

CONCLUSIONS

HIV is an independent risk factor for OHCA, and those who experience OHCA with HIV are much younger than those without HIV. Almost 90% of PWH died 1 month after OHCA. Further research should strive to find out how to reduce OHCA occurrence in this population.

HIV-Tat Exacerbates the Actions of Atazanavir, Efavirenz, and Ritonavir on Cardiac Ryanodine Receptor (RyR2)

The incidence of sudden cardiac death (SCD) in people living with HIV infection (PLWH), especially those with inadequate viral suppression, is high and the reasons for this remain incompletely characterized. The timely opening and closing of type 2 ryanodine receptor (RyR2) is critical for ensuring rhythmic cardiac contraction-relaxation cycles, and the disruption of these processes can elicit Ca²⁺ waves, ventricular arrhythmias, and SCD. Herein, we show that the HIV protein Tat (HIV-Tat: 0-52 ng/mL) and therapeutic levels of the antiretroviral drugs atazanavir (ATV: 0-25,344 ng/mL), efavirenz (EFV: 0-11,376 ng/mL), and ritonavir (RTV: 0-25,956 ng/mL) bind to and modulate the opening and closing of RyR2. Abacavir (0-14,315 ng/mL), bictegravir (0-22,469 ng/mL), Rilpivirine (0-14,360 ng/mL), and tenofovir disoproxil fumarate (0-18,321 ng/mL) did not alter [³H]ryanodine binding to RyR2. Pretreating RyR2 with low HIV-Tat (14 ng/mL) potentiated the abilities of ATV and RTV to bind to open RyR2 and enhanced their ability to bind to EFV to close RyR2. In silico molecular docking using a Schrodinger Prime protein-protein docking algorithm identified three thermodynamically favored interacting sites for HIV-Tat on RyR2. The most favored site resides between amino acids (AA) 1702-1963; the second favored site resides between AA 467-1465, and the third site resides between AA 201-1816. Collectively, these new data show that HIV-Tat, ATV, EFV, and RTV can bind to and modulate the activity of RyR2 and that HIV-Tat can exacerbate the actions of ATV, EFV, and RTV on RyR2. Whether the modulation of RyR2 by these agents increases the risk of arrhythmias and SCD remains to be explored.

HIV-1 Tat Upregulates the Receptor for Advanced Glycation End Products and Superoxide Dismutase-2 in the Heart of Transgenic Mice

Cardiovascular disorder (CVD) is a common comorbidity in people living with HIV (PLWH). Although the underlying mechanisms are unknown, virotoxic HIV proteins, such as the trans-activator of transcription (Tat), likely contribute to CVD pathogenesis. Tat expression in mouse myocardium has been found to induce cardiac dysfunction and increase markers of endothelial toxicity. However, the role that Tat may play in the development of CVD pathogenesis is unclear. The capacity for Tat to impact cardiac function was assessed using AC16 human cardiomyocyte cells and adult male and female transgenic mice that conditionally expressed Tat [Tat(+)], or did not [Tat(-)]. In AC16 cardiomyocytes, Tat increased intracellular calcium. In Tat(+) mice, Tat expression was detected in both atrial and ventricular heart tissue. Tat(+) mice demonstrated an increased expression of the receptor for advanced glycation end products and superoxide dismutase-2 (SOD-2) in ventricular tissues compared to Tat(-) controls. No changes in SOD-1 or α-smooth muscle actin were observed. Despite Tat-mediated changes at the cellular level, no changes in echocardiographic measures were detected. Tat(+) mice had a greater proportion of ventricular mast cells and collagen; however, doxycycline exposure offset the latter effect. These data suggest that Tat exposure promotes cellular changes that can precede progression to CVD.

Outcomes of implantable cardioverter-defibrillator implantation in HIV-infected patients: A single-center retrospective cohort study

BACKGROUND

HIV-infected individuals have a known increased risk of sudden cardiac death (SCD) compared to uninfected individuals. Implantable cardioverter-defibrillators (ICDs) are standard therapy for preventing SCD; however, there is limited data on the outcomes of ICDs in HIV-infected individuals.

HYPOTHESIS

HIV-infected subjects receive a higher number of appropriate ICD therapies than uninfected controls.

METHODS

This is a retrospective cohort study of 35 consecutive HIV-Infected patients and 36 uninfected controls matched by age, race, and gender who were treated at the University of North Carolina Medical Center in the outpatient or inpatient setting from 2014 to the present and had undergone ICD implantation. For HIV-infected subjects, a multivariate Poisson regression analysis was performed to evaluate the association between covariates and ICD therapies.

RESULTS

Among HIV-infected subjects, the mean CD4 count was 582.5 cells/mm³ and 69% had an undetectable viral load. The median follow-up was 6.4 years. HIV-infected subjects had both a higher number of appropriate ICD shocks or antitachycardia pacing (ATP) therapy per person-year as well as a higher number of inappropriate ICD shocks per person-year than uninfected controls (1.512 vs. 0.590 and 0.122 vs. 0.0166, respectively, p < .001 for both comparisons). After multivariate adjustment, the presence of detectable/unsuppressed viral load at the time of ICD implantation was an independent predictor of both of the following in HIV-infected subjects: (1) appropriate ICD discharge (p = .004), and (2) appropriate ICD discharge or appropriate ATP therapy (p < .001).

CONCLUSION

HIV-infected subjects had a higher number of appropriate ICD discharge or ATP therapy per person-year than matched uninfected controls.

Prediction of sudden cardiac arrest in the general population: Review of traditional and emerging risk factors

Sudden cardiac death (SCD) is the most common and devastating outcome of sudden cardiac arrest (SCA), defined as an abrupt and unexpected cessation of cardiovascular function leading to circulatory collapse. The incidence of SCD is relatively infrequent for individuals in the general population, in the range of 0.03-0.10% per year. Yet, the absolute number of cases around the world is high due to the sheer size of the population at risk, making SCA/SCD a major global health issue. Based on conservative estimates, there are at least 2 million cases of SCA occurring worldwide on a yearly basis. As such, identification of risk factors associated with SCA in the general population is an important objective from a clinical and public health standpoint. This review will provide an in-depth discussion of established and emerging factors predictive of SCA/SCD in the general population beyond coronary artery disease and impaired left ventricular ejection fraction. Contemporary studies evaluating the association between age, sex, race, socioeconomic status and the emerging contribution of diabetes and obesity to SCD risk beyond their role as atherosclerotic risk factors will be reviewed. In addition, the role of biomarkers, particularly electrocardiographic ones, on SCA/SCD risk prediction in the general population will be discussed. Finally, the use of machine learning as a tool to facilitate SCA/SCD risk prediction will be examined.

Prevention of sudden cardiac death in persons living with HIV infection

Persons living with HIV infection (PLWH) have been recognized to have an increased risk of sudden cardiac death (SCD). Prevention of this risk should theoretically be included in their long-term management. However, only a few approaches have been proposed to optimize such interventions. Targeting detection of the commonly associated conditions such as coronary artery disease, left ventricular dysfunction, heart failure, QT interval prolongation and ventricular arrhythmias is the first step of this prevention. However, although detection of the risk of SCD is a suitable challenge in PLWH, it remains uncertain whether optimized treatment of the identified risks would unequivocally translate into a decrease in SCD rates.