Presumed Sudden Cardiac Death More Common in HIV-Positive Persons

New data from the Postmortem Systematic Investigation of Sudden Cardiac Death (POST SCD) Study outlines a significantly increased risk of sudden cardiac death (SCD) among patients infected with human immunodeficiency virus (HIV).

Led by investigators from the University of California San Francisco (UCSF), results of the study suggest patients infected with HIV were more than twice as likely to die from SCD as the general population and also had higher levels of interstitial myocardial fibrosis than their counterparts without known HIV infection.

"I would hypothesize that this fibrosis likely represents a systemic impact of chronic HIV infection," said Zian Tseng, MD, Cardiac Electrophysiologist and Professor in the Department of Medicine at UCSF, in a statement. "Our evidence from this study also suggests that there were even higher levels of interstitial fibrosis among the subset of HIV-infected individuals with sudden cardiac death, and also among those with autopsy-confirmed sudden death due to arrhythmias.

Designed by Tseng and colleagues from UCSF, POST SCD leveraged countywide postmortem data from San Francisco County in an effort to expand the existing knowledge base related to SCD. Prior to the completion of the study, investigates noted a disproportionate rate of deaths classified as SCD among patients infected with HIV. Spurred by this, HIV POST SCD was created as a follow-up analysis with the intent of examining the underlying causes of SCD and incidence of SCD caused by arrhythmia in patients infected with HIV.

From February 1, 2011, to September 16, 2016, investigators prospectively identified 1379 deaths among HIV-positive persons between 18-90 years of age. Of these, 610 were unexpected deaths and reported to the medical examiner. Further analysis suggested 109 of the 610 unexpected deaths were attributed to out-of-hospital cardiac arrest and referred for protocol postmortem investigation—investigators noted the family of 1 person declined to provide consent and 108 underwent subsequent autopsy.

Overall, 61 of the 109 deaths did not meet the World Health Organization criteria for presumed SCD. Of the 48 meeting criteria for presumed SCD, only 22 were found to be caused an arrhythmia. Investigators noted the most common cause of SCD was occult drug overdose, which accounted for 16 of the 48 cases. Investigators also pointed the primary EMS impression of all 16 cases was cardiac arrest without evidence or suspicion of drug use. For the purpose of analysis, investigators identified a group of 505 patients without known HIV infection who died from presumed SCD between February 1, 2011, and March 1, 2014.

The incidence rate for presumed SCD among HIV-positive persons was 53.3 per 100,000 person-years and 23.7 per 100,000 person-years in the general population (incidence rate ratio, 2.25; 95% CI, 1.37-3.70). Similarly, the incidence rate of sudden death caused by arrhythmia was greater among those infected with HIV, with rates of 25.0 and 13.3 deaths per 100,000 person-years, respectively, among those with an HIV infection versus those without known HIV (incidence rate ratio, 1.87; 95% CI, 0.93-3.78).

Tissue samples for histologic analysis were obtained from 24 HIV-positive persons and 164 persons within the general population. These analyses indicated the total burden of myocardial fibrosis was grater among HIV-positive persons. Additionally, the burden of interstitial fibrosis, but not replacement fibrosis, was greater among HIV-positive persons.

"I would hypothesize that this fibrosis likely represents a systemic impact of chronic HIV infection," said senior investigator Priscilla Hsue, MD, Chief of the Division of Cardiology at Zuckerberg San Francisco General Hospital and Trauma Center, in the aforementioned statement. "Our evidence from this study also suggests that there were even higher levels of interstitial fibrosis among the subset of HIV-infected individuals with sudden cardiac death, and also among those with autopsy-confirmed sudden death due to arrhythmias. In the future it will be critical to extend upon this finding by identifying at-risk individuals with the purpose of preventing sudden deaths among persons with HIV.

This study, “Sudden Cardiac Death and Myocardial Fibrosis, Determined by Autopsy, in Persons with HIV,” was published in the New England Journal of Medicine.