Methadone Maintenance and QT-Interval: Prevalence and Risk Factors-Is It Effective to Switch Therapy to Levomethadone?

Methadone is a chiral synthetic opioid primarily used to treat heroin and prescription-opioid addiction: the (R)-enantiomer (Levomethadone) activates the µ-opioid receptor more potently than the (S)-enantiomer, which is a more potent blocker of the hERG potassium channels, resulting in QTc prolongation. The purpose of this retrospective study was to assess the effect of methadone on the QTc interval and to investigate the benefits of Levomethadone. The electrocardiograms of 165 patients taking methadone at various dosages and for different periods of time were examined: the QTc value was manually measured and then adjusted using Bazett's formula. Data analysis revealed a linear association between the dosage of methadone and QTc length; no correlation was found between the QTc value and gender, age, or duration of therapy. In total, 14% of the sample (23 patients) showed a prolongation of the QTc interval (>470 ms in males and >480 ms in females); 10 of the 23 patients with QTc elongation underwent a change of therapy from Methadone to Levomethadone-in 90% of these patients, a normalization in the QTc length was established. This study confirmed the role of methadone, specifically its dosage, in QTc prolongation and the efficiency of Levomethadone as an adequate therapeutic substitute in these circumstances. This study validates the importance of careful electrocardiographic monitoring in methadone-treated patients.

Multidisciplinary Management of Opioid Use-Related Infective Endocarditis: Treatment, QTc Values, and Cardiac Arrests due to Ventricular Fibrillation

(1) Background: The opioid epidemic has led to an increase in cardiac surgery for infective endocarditis (IE-CS) related to injection use of opioids (OUD) and other substances and a call for a coordinated approach to initiate substance use disorder treatment, including medication for OUD (MOUD), during IE-CS hospitalizations. We sought to determine the effects of the initiation of a multi-disciplinary endocarditis evaluation team (MEET) on MOUD use, electrocardiographic QTc measurements and cardiac arrests due to ventricular fibrillation (VF) in patients with OUD. (2) Methods and Results: A historical group undergoing IE-CS at Yale-New Haven Hospital prior to MEET initiation, Group I (43 episodes of IE-CS, 38 patients) was compared to 24 patients undergoing IE-CS after MEET involvement (Group II). Compared to Group l, Group II patients were more likely to receive MOUD (41.9 vs. 95.8%, p < 0.0001), predominantly methadone (41.9 vs. 79.2%, p = 0.0035) at discharge. Both groups had similar QTcs: approximately 30% of reviewed electrocardiograms had QTcs ≥ 470 ms and 17%, QTcs ≥ 500 ms. Cardiac arrests due to VF were not uncommon: Group I: 9.3% vs. Group II: 8.3%, p = 0.8914. Half occurred in the 1-2 months after surgery and were contributed to by pacemaker malfunction/ management and half were related to opioid use. (3) Conclusions: MEET was associated with increased MOUD (predominantly methadone) use during IE-CS hospitalizations without an increase in QTc prolongation or cardiac arrest due to VF compared to Group I, but events occurred in both groups. These arrests were associated with pacemaker issues or a return to opioid use. Robust follow-up of IE-CS patients is essential, as is further research to clarify the longer-term effects of MEET on outcomes.

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.

Accuracy of a single-lead mobile smartphone electrocardiogram for QT interval measurement in patients undergoing maintenance methadone therapy

STUDY OBJECTIVE

Methadone is associated with QT interval prolongation and torsades de pointes. Expert panel recommendations advocate a pre-methadone electrocardiogram (ECG) and another ECG at 30 days of therapy in patients with risk factors. Some guidelines recommend a pre-methadone ECG and routine ECG monitoring in all methadone patients, but this is controversial due to the resources required. Availability of a convenient, less resource-intensive method of ECG monitoring for patients taking methadone is desirable. The objective of this study was to assess the accuracy of a handheld smartphone ECG (iECG) for QT measurement in patients on maintenance methadone therapy in an urban opioid treatment program.

DESIGN

Prospective study.

SETTING

Urban opioid treatment program.

PATIENTS

n = 115 patients in normal sinus rhythm who were on steady-state maintenance methadone therapy INTERVENTION: Patients (n = 115) underwent a simultaneous 12-lead ECG and a single-lead iECG.

MEASUREMENTS AND MAIN RESULTS

The first three QT and RR intervals from lead II of the 12-lead ECG and simulated lead I from the iECG were compared using the Bland-Altman analysis of measurement agreement. Mean [± standard deviation) age was 34 ± 11 years; 71% were female, 75% were white. Compared to the 12-lead ECG, the iECG was associated with a QTc bias of - 0.14 ms (SD = 12 ms, 95% CI = -2.4 to 2.1 ms). The absolute mean difference in QTc between the two methods was 9.5 ± 7.1 ms. For identification of patients with methadone-associated QTc prolongation, the iECG performed moderately well [c-statistic 0.97 (95% CI 0.91-0.99); sensitivity and specificity 75% (95% CI 43-95%) and 99% (95% CI 94-99%), respectively]. The positive and negative likelihood ratios of the iECG for identifying patients with methadone-associated QTc prolongation were 77.25 (95% CI 10.69 to 558.18) and 0.25 (95% CI 0.09 to 0.67), respectively, while the positive and negative predictive values were 90% (95% CI 56-99%) and 97% (95% CI 92-99%), respectively. The accuracy of the iECG for identifying patients with QTc prolongation was 97% (95% CI 91-99%).

CONCLUSION

A handheld smartphone ECG is accurate for QT interval measurement in patients taking maintenance methadone therapy, and its performance is moderately good for identifying patients with methadone-associated QTc prolongation.

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

HIV‐infected individuals have an increased risk of sudden cardiac death compared to the general population; yet the mechanisms underlying this increased risk remain unclear. The mechanisms underlying the heightened sudden cardiac death risk in HIV‐infected individuals is likely multifactorial. We reviewed the literature to elucidate and summarize the potential mechanisms contributing to sudden cardiac death in the HIV patient population. There is biologic plausibility that the following mechanisms may be contributing to the significantly heightened risk of sudden cardiac death in HIV to varying degrees: ventricular arrhythmias, myocardial fibrosis and scar, prolonged QTc interval (both as a direct effect of HIV on repolarization as well as a result of concurrent medications/antiretroviral therapies), substance abuse, structural heart disease, and premature atherosclerosis. Further understanding of the mechanisms underlying the increased sudden cardiac death risk in HIV can lead to identification of modifiable risk factors, implementation of public health programs, and potential revision of ICD implantation guidelines to ultimately reduce the incidence of sudden cardiac death in HIV‐infected patients. Further studies are needed to assess the relative contribution of each of these mechanisms and risk factors.

Abnormal QTc syndrome in HIV-infected patients: a systematic review of prevalence and risk factors

BACKGROUND

The purpose of this review is to critically analyse data regarding the prevalence and risk factors for developing a prolonged QTc interval and subsequent sudden cardiac death (SCD) in persons living with HIV (PLWH).

METHODS

A systematic literature search using PubMed and Google Scholar databases was performed using the following search terms: 'HIV and prolonged QTc' and 'managing HIV-patients with prolonged QTc'. References within articles of interest were also evaluated.

RESULTS/DISCUSSION

PLWH are at an increased risk of having a prolonged QTc interval. Some risk factors for this include the virus itself, concomitant medications, comorbid conditions, addictions and electrolyte disturbances. PLWH who have an increased HIV RNA viral load or decreased CD4⁺ T-cell count are at further risk for progressing to sudden cardiac death (SCD). Many medications commonly prescribed in the PLWH population, such as antiretrovirals and antimicrobials used in opportunistic infection prophylaxis, have also been shown to promote QTc prolongation through inhibition of human ether-a-go-go potassium channels or through drug metabolism inhibition of other QTc prolonging drugs.

CONCLUSIONS

Due to the high number of risk factors associated with QTc prolongation, clinicians should incorporate baseline and routine ECG monitoring for PLWH to potentially lower the increased risk of SCD in PLWH.

Prolonged QTc in HIV-Infected Patients: A Need for Routine ECG Screening

BACKGROUND

With HIV-infected patients living longer, there is an increased burden of comorbidities related to aging, HIV itself, and polypharmacy. Cardiac morbidity is of particular importance.

METHODS

This 2-group comparison study (156 HIV-positive and 105 HIV-negative patients) investigated the prevalence of abnormalities in and factors associated with an electrocardiogram (ECG) measure, corrected QT interval (QTc), where prolongation can lead to arrhythmia and sudden death. Medications prescribed (antiretroviral therapy, psychiatric medications, methadone, and antibiotics) at the time of ECG were noted. Patient characteristics, medications, QTc, and ECG characteristics were compared between the 2 groups.

RESULTS

Prolongation (29% versus 19%) and extreme prolongation (6% versus 1%) in QTc were more frequent in those with HIV. Antiretroviral therapy was associated with lower odds of prolonged QTc (odds ratio [OR] = 0.35; P = .04), while methadone with higher odds (OR = 4.6; P = .01) in HIV-positive patients. With methadone and medication groups adjusted, HIV status was still associated with 17-millisecond longer QTc ( P = .04).

CONCLUSION

This study provides evidence that patients with HIV may have clinically relevant longer QTc interval on ECG. Baseline and routine ECG monitoring may be warranted among patients living with HIV in clinical practice based on cumulative evidence.

QT prolongation in HIV-positive patients: Review article

Introduction

Antiretrovirals have immensely increased the average life expectancy of HIV-positive patients. However, the incidence of QT interval prolongation and other arrhythmias has also increased.

Methods

Pubmed and Google Scholar were searched for relevant literature published between 1990 and 2019.

Results and discussion

HIV-positive patients with high viral load, low CD4 count, chronic inflammation, and autonomic neuropathy can develop QT interval prolongation. Another factor prolonging QT interval includes exposure to the HIV transactivator protein, which inhibits hERG K (+) channels controlling IKr K (+) currents in cardiomyocytes. Protease inhibitors inhibiting the CYP3A4 enzyme can also lead to QT interval prolongation. QT interval prolongation can potentially be exacerbated by opioids, antipsychotics, antibiotics, and antifungals, the adjunct medications often used in HIV-positive patients. Hepatic insufficiency in seropositive patients on antiretrovirals may also increase the risk of QT interval prolongation.

Conclusion

Baseline and follow-up EKG in the susceptible population is suggested.

Prevalence and risk factors of prolonged QT interval and electrocardiographic abnormalities in persons living with HIV

OBJECTIVE

Abnormal ECGs are associated with increased risk of arrhythmias and sudden cardiac death. We aimed to investigate the prevalence and associated risk factors of prolonged QTc and major ECG abnormalities, in persons living with HIV (PLWH) and uninfected controls.

DESIGN

PLWH aged at least 40 years were recruited from the Copenhagen comorbidity in HIV infection (COCOMO) study and matched on sex and age to uninfected controls from the Copenhagen General Population Study.

METHODS

ECGs were categorized according to Minnesota Code Manual of ECG Findings definition of major abnormalities. A QT interval corrected for heart rate (QTc) greater than 440 ms in men and greater than 460 ms in women was considered prolonged. Pathologic Q-waves were defined as presence of major Q-wave abnormalities.

RESULTS

ECGs were available for 745 PLWH and 2977 controls. Prolonged QTc was prevalent in 9% of PLWH and 6% of controls, P = 0.052. Pathologic Q-waves were more common in PLWH (6%) than in controls (4%), P = 0.028. There was no difference in prevalence of major ECG abnormalities between PLWH and controls, P = 0.987.In adjusted analyses, HIV was associated with a 3.6 ms (1.8-5.4) longer QTc interval, P < 0.001, and HIV was independently associated with prolonged QTc [adjusted odds ratio: 1.59 (1.14-2.19)], P = 0.005. HIV was borderline associated to pathologic Q-waves after adjusting, P = 0.051.

CONCLUSION

HIV was associated with higher odds ratio of prolonged QTc after adjustment for cardiovascular risk factors, but analyses were not adjusted for QT-prolonging medication. Although evidence indicated more pathologic Q-waves in PLWH, the risk seemed to be associated mainly with an adverse risk profile.

Association between Use of Methadone, Other Central Nervous System Depressants, and QTc Interval-Prolonging Medications and Risk of Mortality in a Large Cohort of Women Living with or at Risk for Human Immunodeficiency Virus Infection

STUDY OBJECTIVE

To evaluate the association between use of methadone, other central nervous system (CNS) depressants, and QTc interval-prolonging medications and risk of mortality among human immunodeficiency virus (HIV)-infected and at-risk HIV-uninfected women.

DESIGN

Multicenter, prospective, observational cohort study (Women's Interagency HIV Study [WIHS]).

PARTICIPANTS

A total of 4150 women enrolled in the WIHS study between 1994 and 2014 who were infected (3119 women) or not infected (1031 women) with HIV.

MEASUREMENTS AND MAIN RESULTS

Data on medication utilization were collected from all study participants via interviewer-administered surveys at 6-month intervals (1994-2014). Mortality was confirmed by National Death Index data. With age defining the time scale for the analysis, Cox proportional hazards models were used to estimate hazard ratios (HRs) for all-cause mortality in HIV-infected and -uninfected women and non-acquired immunodeficiency syndrome (AIDS) deaths in HIV-infected women. A total of 1046 deaths were identified, of which 429 were considered non-AIDS deaths. Use of benzodiazepines, CNS depressants (excluding methadone), and number of medications with conditional QTc interval-prolonging effects were each associated with all-cause mortality in multivariate models of HIV-infected women: hazard ratio (HR) 1.28, 95% confidence interval (CI) 1.01-1.60, p=0.037; HR 1.61, 95% CI 1.35-1.92, p<0.0001; and HR 1.15 per drug, 95% CI 1.00-1.33, p=0.047, respectively. Other explanatory variables for all-cause mortality in this model included HIV viral load, CD4+  cell count, renal function, hemoglobin and albumin levels, HIV treatment era, employment status, existence of depressive symptoms, ever use of injection drugs, and tobacco smoking. Of interest, use of CNS depressants (excluding methadone) was also associated with non-AIDS deaths (HR 1.49, 95% CI 1.49-2.2, p<0.0001). Although use of benzodiazepines and conditional QT interval-prolonging medications were associated with increased risk of non-AIDS mortality (HR 1.32 and 1.25, respectively), the effect was not statistically significant (p>0.05).

CONCLUSION

In this cohort of HIV-infected and at-risk HIV-uninfected women, use of benzodiazepines, CNS depressants, and conditional QTc interval-prolonging medications were associated with a higher risk of mortality independent of methadone and other well-recognized mortality risk factors. Care must be taken to assess risk when prescribing these medications in this underserved and at-risk patient population.

Getting to the Heart of the Matter: A Review of Drug Interactions Between HIV Antiretrovirals and Cardiology Medications

The past 20 years have seen remarkable advances in the treatment of HIV such that most people diagnosed with HIV today can live long, healthy lives by taking antiretrovirals which are usually life-long. Advancements in antiretroviral therapy include the availability of well tolerated, single tablet regimens that are associated with a lower risk of drug-drug interactions. Despite this, many people living with HIV infection might be taking antiretroviral agents that are associated with significant drug-drug interactions. Because HIV infection itself is associated with cardiovascular complications and this population is living longer, concomitant use of antiretrovirals and medications to treat cardiovascular-related diseases is often required. For this reason, it is imperative that clinicians are aware of the potential for clinically significant drug-drug interactions between antiretroviral agents and cardiac medications as well as the useful HIV drug interaction resources that might provide guidance. Available data on significant interactions are summarized and suggested guidance regarding management is discussed.

Mechanisms of Arrhythmia and Sudden Cardiac Death in Patients With HIV Infection

Long-term survival of HIV-infected patients has significantly improved with the use of antiretroviral therapy (ART). As a consequence, cardiovascular diseases are now emerging as an important clinical problem in this population. Sudden cardiac death is the third leading cause of mortality in HIV patients. Twenty percent of patients with HIV who died of sudden cardiac death had previous cardiac arrhythmias including ventricular tachycardia, atrial fibrillation, and other unspecified rhythm disorders. This review presents a summary of HIV-related arrhythmias, associated risk factors specific to the HIV population, and underlying mechanisms. Compared with the general population, patients with HIV have several cardiac conditions and electrophysiological abnormalities. As a result, they have an increased risk of developing severe arrhythmias, that can lead to sudden cardiac death. Possible explanations may be related to non-ART polypharmacy, electrolyte imbalances, and use of substances observed in HIV-infected patients; many of these conditions are associated with alterations in cardiac electrical activity, increasing the risk of arrhythmia and sudden cardiac death. However, clinical and experimental evidence has also revealed that cardiac arrhythmias occur in HIV-infected patients, even in the absence of drugs. This indicates that HIV itself can change the electrophysiological properties of the heart profoundly and cause cardiac arrhythmias and related sudden cardiac death. The current knowledge of the underlying mechanisms, as well as the emerging role of inflammation in these arrhythmias, are discussed here.

Tobacco, illicit drugs use and risk of cardiovascular disease in patients living with HIV

PURPOSE OF REVIEW

There is a strong link between HIV, smoking and illicit drugs. This association could be clinically relevant as it may potentiate the risk of cardiovascular diseases (CVD). The purpose of this review is to bring readers up to date on issues concerning the cardiovascular risk associated with tobacco and illicit drugs in patients living with HIV (PLHIV), examining the studies related to this topic published in the last year.

RECENT FINDINGS

There is a strong association between smoking and atherosclerotic disease in PLHIV, reducing life expectancy secondary to CVD by up to 6 years. Illicit drugs were associated with increased risk of atherosclerotic problems but to a lesser extent than smoking. A significant association of drugs such as cocaine with subclinical coronary atherosclerosis been demonstrated. The relation of marijuana, heroin and amphetamines with atherosclerosis generates more controversy. However, those drugs are associated with cardiovascular morbidity, independently of smoking and other traditional risk factors.

SUMMARY

Tobacco and illicit drugs are linked to CVD in HIV patients. This leads to the need to create special programs to address the addiction to smoking and illicit drugs, in order to mitigate their consequences and reduce cardiovascular risk.

Prevalence and predictors of long corrected QT interval in HIV-positive patients: a multicenter study

AIMS

HIV and highly active antiretroviral therapy (HAART) may affect cardiac conduction, and a higher incidence of sudden death has been recognized in HIV-positive patients. Nevertheless, predictors of prolonged corrected QT interval (cQT) have been poorly described. The aim of the study was to investigate the prevalence and predictors of long cQT in a cohort of HIV-positive patients.

METHODS

Consecutive HIV-positive patients followed in a primary prevention clinic at two Italian institutions were retrospectively enrolled. A 12-lead ECG was recorded in all patients; main clinical features were collected. Prevalence of long cQT (defined as cQT >470 ms in women and >450 ms in men) was the primary end-point. Secondary end-points were the identification of predictors of cQT prolongation, and the association between HAART and HIV-related features with long cQT.

RESULTS

Three hundred and fifty-one HIV-positive patients were included, 26 (7.4%) with long cQT. Mean age was higher among those with long cQT (51.6 vs. 57.6 years; P = 0.007). A higher prevalence of long cQT was reported for patients with a CD4+ cell count below 200 cells/μl at the moment of ECG (60 vs. 24.2%; P = 0.002) and with a nadir of CD4+ cell count below 200 cells/μl (91.3 vs. 58.6%; P = 0.001). At multivariate analysis, only the nadir of CD4+ cell count below 200 cells/μl consistently related to the presence of long cQT (odds ratio 5.8, 95% confidence interval 1.3-26.4).

CONCLUSION

A low CD4+ cell count is associated with long cQT independently from HAART in HIV-positive patients and may be useful to correctly stratify arrhythmic risk in these patients.

Prolongation of the QTc interval in HIV-infected individuals compared to the general population

OBJECTIVES

Prolonged QT interval is associated with arrhythmias and sudden death. An increased prevalence of QT interval prolongation in human immunodeficiency virus-infected (HIV) subjects was previously described. The impact of different medications and HIV infection itself on the QT interval is rarely investigated in large HIV+ cohorts.

METHODS

We compared QT interval measurement in 496 HIV(+) patients of the HIV-HEART study (HIVH) and 992 sex- and age-matched controls of the population-based German Heinz Nixdorf Recall study (HNR). QT corrected for heart rate (QTc) >440 ms in male and >460 ms in female was considered pathological. We analysed the impact of HIV status and HIV medication on QTc prolongation in the HIVH subjects.

RESULTS

We observed longer QTc in HIVH subjects compared with HNR controls: 424.1 ms ± 23.3 vs. 411.3 ± 15.3 ms for male and 435.5 ms ± 19.6 vs. 416.4 ms ± 17.3 for female subjects (p < 0.0001 for both sexes). Adjusting for QT prolonging medication the mean differences in QTc between the two studies remained significant with 12.6 ms (95% CI 10.5-14.8; p value <0.0001) for male and 19.3 ms (95% CI 14.5-24.2; p value <0.0001) for female subjects. Prolongation of QTc was pathologic in 22.8 vs. 3.9% of HIV(+) and non-infected males and in 12.1 vs. 1.8% of the females [OR of 7.9 (5.0-12.6) and OR of 6.7 (1.8-24.2), respectively]. Smoking behaviour was an independent factor to lengthen QTc in HIV(+) patients. Diabetes mellitus was not a risk factor itself, but might be associated with medication which was associated with LQT. We could not observe any influence of the HIV status, ART, or any co-medication on the QTc.

CONCLUSIONS

Our study showed that HIV(+) patients had significantly longer QTc intervals compared to the general population. The number of patients with pathologic QTc prolongation was significantly increased in HIV(+) population.

QT interval prolongation in opioid agonist treatment: analysis of continuous 12-lead electrocardiogram recordings

Aims

Methadone is a widely used opioid agonist treatment associated with QT prolongation and torsades de pointes. We investigated the QT interval in patients treated with methadone or buprenorphine using continuous 12‐lead Holter recordings.

Methods

We prospectively made 24‐h Holter recordings in patients prescribed methadone or buprenorphine, compared to controls. After their normal dose a continuous 12‐lead Holter recorder was attached for 24 h. Digital electrocardiograms were extracted hourly from the Holter recordings. The QT interval was measured automatically (H‐scribe software, Mortara Pty Ltd) and checked manually. The QT interval was plotted against heart rate (HR) on the QT nomogram to determine abnormality. Demographics, dosing, medical history and laboratory investigations were recorded.

Results

There were 58 patients (19 methadone, 20 buprenorphine and 19 control); median age 35 years (20–56 years); 33 males. Baseline characteristics were similar. Median dose of methadone was 110 mg day^–1 (70–170 mg day^–1) and buprenorphine was 16 mg day^–1 (12–32 mg day^–1). Seven participants had abnormal QT intervals. There was a significant difference in the proportion of prescribed methadone with abnormal QT intervals, 7/19 (37%; 95% confidence interval: 17–61%), compared to controls 0/19 (0%; 95% confidence interval: 0–21%; P = 0.008), but no difference between buprenorphine and controls (0/20). QT vs. HR plots showed patients prescribed methadone had higher QT‐HR pairs over 24 h compared to controls. There was no difference in dose for patients prescribed methadone with abnormal QT intervals and those without.

Conclusions

Methadone is associated with prolonged QT intervals, but there was no association with dose. Buprenorphine did not prolong the QT interval. Twenty four‐hour Holter recordings using the QT nomogram is a feasible method to assess the QT interval in patients prescribed methadone.

Drug-induced torsades de pointes in an underserved urban population. Methadone: is there therapeutic equipoise?

BACKGROUND

Although it has been well established that methadone use can result in prolonged QTc/torsades de pointes (TdP) and has been labeled as one of the main drugs that cause TdP, it is still prescribed indiscriminately, and several cases of methadone-associated TdP have been seen in our community.

METHODS

Our objective was to determine the associated factors for prolonged QTc and the development of torsades de pointes (TdP) in our underserved patient population. We found 12,550 ECGs with prolonged QTc between 2002 and 2013. Medical records were reviewed in order to identify precipitating factors for prolonged QTc and to detect incidence of TdP.

RESULTS

We identified 2735 patients with prolonged QTc who met the inclusion criteria. Of these, 89 (3%) experienced TdP. There was a greater prevalence of HIV infection in the TdP group (11.2 vs. 3.7%, p < 0.001). Furosemide, hydrochlorothiazide, selective serotonin reuptake inhibitors (SSRIs), amiodarone, ciprofloxacin, methadone, haloperidol, and azithromycin were the drugs most often associated with prolonged QTc (31, 8.2, 7.6, 7.1, 3.9, 3.4 and 3.3%, respectively). However, the agents most commonly associated with TdP were furosemide (39.3%), methadone (27%), SSRIs (19.1%), amiodarone (18%), and dofetilide (9%). The medications with statistical significance in the multivariate analysis for TdP development in descending order were as follows: ranolazine (odds ratios [OR] = 53.61, 95% confidence interval [CI] 5.4-524, p < 0.001), dofetilide (OR = 25, CI 6.47-103.16, p < 0.001), voriconazole (OR = 21.40, CI 3.24-124.25, p < 0.001), verapamil (OR = 10.98, CI 2.62-44.96, p < 0.001), sotalol (OR = 12.72, 1.95-82.81, p = 0.008), methadone (OR = 9.89, CI 4.05-24.15, p < 0.001), and SSRI (OR = 2.26, CI 1.10-5.96, p < 0.001). This multivariate analysis revealed that amiodarone and HIV infection were not implicated in TdP.

CONCLUSION

Methadone was by far the leading medication implicated in the development of TdP and an independent predictor in both univariate and multivariate analyses despite the fact that it was not the most common QT-prolonging medication in our population.

Risk of cardiovascular disease associated with HCV and HBV coinfection among antiretroviral-treated HIV-infected individuals

BACKGROUND

The increased risk for cardiovascular disease (CVD) in HIV is well established. Despite high prevalence of viral hepatitis coinfection with HIV, there are few studies on the risk of CVD amongst antiretroviral therapy (ART)-treated coinfected patients.

METHODS

Ontario HIV Treatment Network Cohort Study participants who initiated ART without prior CVD events were analysed. HBV and HCV coinfection were identified by serology and RNA test results. CVD was defined as any of: coronary artery disease including atherosclerosis, chronic ischaemic heart disease and arteriosclerotic vascular disease; myocardial infarction; congestive heart failure; cerebrovascular accident or stroke; coronary bypass; angioplasty; and sudden cardiac death. The impact of HBV and HCV coinfection on time to CVD was assessed using multivariable competing risk models accounting for left truncation between ART initiation and study enrolment.

RESULTS

A total of 3,416 HIV-monoinfected, 432 HIV-HBV- and 736 HIV-HCV-coinfected individuals were followed for a median (IQR) of 2.32 years (1.36-8.02). Over the study period, 167 CVD events and 613 deaths were documented. After adjustment for age, gender, race, year initiating ART, weight and smoking status, HBV was not associated with time to CVD onset (aHR=1.05, 95% CI [0.63, 1.74]; P=0.86). There was an elevated risk of CVD for HCV-coinfected individuals, which approached statistical significance (aHR=1.44, 95% CI [0.97, 2.13]; P=0.07).

CONCLUSIONS

Our results are consistent with a moderate increase of CVD among individuals with HIV-HCV coinfection relative to those with HIV infection alone, lending support to consideration of initiation of HCV antiviral treatment.

Influence of immune activation and inflammatory response on cardiovascular risk associated with the human immunodeficiency virus

Patients infected with the human immunodeficiency virus (HIV) have an increased cardiovascular risk. Although initially this increased risk was attributed to metabolic alterations associated with antiretroviral treatment, in recent years, the attention has been focused on the HIV disease itself. Inflammation, immune system activation, and endothelial dysfunction facilitated by HIV infection have been identified as key factors in the development and progression of atherosclerosis. In this review, we describe the epidemiology and pathogenesis of cardiovascular disease in patients with HIV infection and summarize the latest knowledge on the relationship between traditional and novel inflammatory, immune activation, and endothelial dysfunction biomarkers on the cardiovascular risk associated with HIV infection.