NATAP: Sudden Cardiac Death in HIV+

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Subject: NATAP: Sudden Cardiac Death in HIV+HIV Linked to Risk of Sudden Cardiac Death - (05/15/12) new study"One of the most feared manifestations of CVD is

sudden cardiac death (SCD), responsible for 5% to 15% of total deaths in the U.S. (1,2). Many SCDs occur in patients previously undiagnosed with CVD (3), making the identification of high-risk populations important for screening and prevention.""Given that cardiac symptoms were common in victims of SCD, aggressive primary prevention of CVD should be considered in HIV-infected patients, especially those with traditional risk factors.....As we seek to reduce mortality in an aging HIV-infected population, greater attention must be directed to the mechanisms underlying SCD, with the goal of identifying at-risk patients

and ultimately preventing sudden death.""HIV-infected patients also have a higher prevalence of prolonged corrected QT interval (8), a risk factor for malignant arrhythmia and cardiovascular mortality in otherwise healthy subjects (24).....Chronic HIV-associated inflammation is thought to underlie many non-AIDS conditions, including CVD, consistent with studies demonstrating increased all-cause mortality and acute MI risk in

patients with higher levels of serum high-sensitivity C-reactive protein.......Patients with SCD had modest immunodeficiency, with similar CD4 counts (median 312 cells/mm3) and viral loads (median 3.8 log copies/ml) as the full cohort (353 cells/mm3 and 4.1 log copies/ml, respectively), suggesting that patients are susceptible to SCD even in the setting of mild HIV disease"Individuals with HIV have higher rates of CVD than uninfected subjects, likely because of a combination of traditional

risk factors, HIV-related inflammation, and antiretroviral therapy (4,5). Cardiovascular abnormalities strongly associated with SCD are prevalent in HIV-infected patients, including cardiomyopathy (6), pulmonary hypertension (7), and prolonged corrected QT interval (8). Although most persons with HIV still die of acquired immune deficiency syndrome (AIDS) (9), given the increased prevalence of CVD in this population, SCD is likely an important contributor to overall mortality.

Thus, we sought to determine the incidence, clinical characteristics, and predictors of SCD over the past decade in a large cohort of patients

receiving care at an urban, public HIV clinic.""We found that SCDs (sudden cardiac death) constituted an unexpectedly high proportion of overall deaths in this urban HIV cohort, with most cardiac deaths presenting suddenly. SCD occurred at a rate more than 4 times expected in the general population,

with similar risk factors. Given that cardiac symptoms were common in victims of SCD, aggressive primary prevention of CVD should be considered in HIV-infected patients, especially those with traditional risk factors. Although implantable cardioverter-defibrillators have been

shown to be life saving in certain clinical settings (16), no studies have evaluated their utility specifically for patients with HIV. As we seek to reduce mortality in an aging HIV-infected population, greater attention must be directed to the mechanisms underlying SCD, with the goal of identifying at-risk patients and ultimately preventing sudden death.""SCDs accounted for 30 of 35 (86%; 95% CI: 70% to 95%) of all cardiac deaths.""Compared with AIDS and natural deaths combined,

SCDs had a higher prevalence of prior myocardial infarction (17% vs. 1%, p < 0.0005), cardiomyopathy (23% vs. 3%, p < 0.0005), heart failure (30% vs. 9%, p = 0.004), and arrhythmias (20% vs. 3%, p = 0.003).""Of 2,860 cohort patients, 2,478 (87%) were men and 1,515 (53%) were Caucasian; among those with known HIV risk factors (n = 2,482), 1,778 (72%) were men who had sex with men, 165 (7%) were injection drug users, and 519 (21%) had heterosexual risk. At entry, the

median age was 39 years (interquartile range: 33 to 45 years), the median CD4 count was 353 cells/mm3 (interquartile range: 175 to 551 cells/mm3; mean 390 cells/mm3), the median log viral load was 4.1 copies/ml (interquartile range: 2.9 to 4.9 copies/ml; mean 3.9 copies/ml), and 578 subjects (21%) had undetectable HIV ribonucleic acid

(<200 copies/ml), indicative of successful antiretroviral therapy.""Three patients with SCD underwent autopsy; causes of death were myocardial infarction (MI) (n = 2) and severe cardiomyopathy. More than half of patients with SCD had histories of tobacco, alcohol, or drug use. Five patients (17%) had family histories of CVD, and 80% had either known CVD or CVD risk factors. At their final

clinic visits, 33% reported chest pain, palpitations, syncope, and/or dyspnea; 83% were prescribed cardiac medications. Thirteen (43%) underwent echocardiography: 8 showed moderately to severely reduced ejection fractions, 7 diastolic dysfunction, and 3 pulmonary hypertension. Three of 6 patients who underwent stress testing demonstrated ischemia; coronary angiography in 2 patients demonstrated no significant stenoses. Of 23 patients with electrocardiograms, 1 had atrial fibrillation, 8 met criteria for left ventricular hypertrophy, 1 had a prolonged corrected QT interval, and 4 showed evidence of prior MIs."