Twelve-month follow-up results from the SIRONA 2 clinical trial.

AIMS: In the SIRONA 2 trial, the safety and efficacy of pulmonary artery (PA) pressure (PAP)-guided heart failure (HF) management using a novel PAP sensor were assessed at 30 and 90 days, respectively, and both endpoints were met. The current study examines the prespecified secondary endpoints of safety and accuracy of the PA sensor along with HF hospitalizations and mortality, HF symptoms, functional capacity, quality of life, and patient compliance through 12 months. METHODS AND RESULTS: SIRONA 2 is a prospective, multi-centre, open-label, single-arm trial evaluating the Cordella™ PA Sensor System in 70 patients with New York Heart Association (NYHA) functional class III HF with a prior HF hospitalization and/or increase of N-terminal pro-brain natriuretic peptide within 12 months of enrolment. Sensor accuracy was assessed and compared with measurements obtained by standard right heart catheterization (RHC). Safety was defined as freedom from prespecified adverse events associated with use of the Cordella PA Sensor System and was assessed in all patients who entered the cath lab for PA sensor implant. HF hospitalizations and mortality, HF symptoms, functional capacity, quality of life, and patient compliance were also assessed. At 12 months, there was good agreement between the Cordella PA Sensor System and RHC, with the average difference for mean PAP being 2.9 ± 7.3 mmHg. The device safety profile was excellent with 98.4% freedom from device/system-related complications. There were no pressure sensor failures. HF hospitalizations and mortality were low with a rate of 0.33 event per patient year. Symptoms as assessed by NYHA (P < 0.0001) and functional capacity as measured by 6 min walk test (P = 0.02) were significantly improved. Patients' adherence to daily transmissions of PAP and vital signs measurements was 95%. CONCLUSIONS: Long-term follow-up of the SIRONA 2 trial supports the safety and accuracy of the Cordella PA Sensor System in enabling comprehensive HF management in NYHA class III HF patients.

Safety and efficacy of a wireless pulmonary artery pressure sensor: primary endpoint results of the SIRONA 2 clinical trial.

AIMS: Implantable pulmonary artery pressure (PAP) sensors have been shown to reduce heart failure hospitalizations (HFH) in selected patients. The goal of this study was to evaluate the safety and efficacy of a novel wireless PAP monitoring system in patients with heart failure (HF). METHODS AND RESULTS: This is a prospective, multi-centre, open-label, single-arm trial evaluating the safety and efficacy of the Cordella™ PA Sensor System including the comprehensive Cordella™ Heart Failure System (CHFS) in patients with New York Heart Association (NYHA) Class III heart failure with a heart failure hospitalization and/or increase of N-terminal pro-Brain Natriuretic Peptide (NT-proBNP) within 12 months of enrolment. The primary efficacy endpoint was the accuracy of PA sensor mean PAP measurements, compared with fluid-filled catheter mean PAP measurements obtained by standard right heart catheterization (RHC) at 90 days post-implant, assessed in all patients with a successful implant. The primary safety endpoint was freedom from adverse events associated with use of the Cordella PA Sensor System through 30 days post-implant, assessed in all patients who entered the cath lab for PA sensor implant. The PA sensor was successfully implanted in 70 patients. Equivalence between the PA sensor and RHC for mean pulmonary artery pressures was excellent with measurements confined within the equivalence bounds of -4.0 to 4.0 mmHg (mean PAP: 0.0 to 2.9 mmHg, P = 0.003). The device safety profile was excellent with 98.6% freedom from Device System Related Complications, defined as invasive treatment, device explant or death. There were no pressure sensor failures. Patients' adherence to daily measurement transmissions of PAP and vital signs was 94%. CONCLUSIONS: This trial supports the safety and efficacy of the Cordella PA Sensor System and in conjunction with the CHFS enables comprehensive HF management in NYHA class III heart failure patients.

microRNA-155 Is Decreased During Atherosclerosis Regression and Is Increased in Urinary Extracellular Vesicles During Atherosclerosis Progression.

Background: Atherosclerosis is a chronic inflammatory disease driven by macrophage accumulation in medium and large sized arteries. Macrophage polarization and inflammation are governed by microRNAs (miR) that regulate the expression of inflammatory proteins and cholesterol trafficking. Previous transcriptomic analysis led us to hypothesize that miR-155-5p (miR-155) is regulated by conjugated linoleic acid (CLA), a pro-resolving mediator which induces regression of atherosclerosis in vivo. In parallel, as extracellular vesicles (EVs) and their miR content have potential as biomarkers, we investigated alterations in urinary-derived EVs (uEVs) during the progression of human coronary artery disease (CAD). Methods: miR-155 expression was quantified in aortae from ApoE-/- mice fed a 1% cholesterol diet supplemented with CLA blend (80:20, cis-9,trans-11:trans-10,cis-12 respectively) which had been previously been shown to induce atherosclerosis regression. In parallel, human polarized THP-1 macrophages were used to investigate the effects of CLA blend on miR-155 expression. A miR-155 mimic was used to investigate its inflammatory effects on macrophages and on ex vivo human carotid endarterectomy (CEA) plaque specimens (n = 5). Surface marker expression and miR content were analyzed in urinary extracellular vesicles (uEVs) obtained from patients diagnosed with unstable (n = 12) and stable (n = 12) CAD. Results: Here, we report that the 1% cholesterol diet increased miR-155 expression while CLA blend supplementation decreased miR-155 expression in the aorta during atherosclerosis regression in vivo. CLA blend also decreased miR-155 expression in vitro in human THP-1 polarized macrophages. Furthermore, in THP-1 macrophages, miR-155 mimic decreased the anti-inflammatory signaling proteins, BCL-6 and phosphorylated-STAT-3. In addition, miR-155 mimic downregulated BCL-6 in CEA plaque specimens. uEVs from patients with unstable CAD had increased expression of miR-155 in comparison to patients with stable CAD. While the overall concentration of uEVs was decreased in patients with unstable CAD, levels of CD45+ uEVs were increased. Additionally, patients with unstable CAD had increased CD11b+ uEVs and decreased CD16+ uEVs. Conclusion: miR-155 suppresses anti-inflammatory signaling in macrophages, is decreased during regression of atherosclerosis in vivo and is increased in uEVs from patients with unstable CAD suggesting miR-155 has potential as a prognostic indicator and a therapeutic target.

Strategies to address the shortcomings of commonly used advanced chronic heart failure descriptors to improve recruitment in palliative care research: A parallel mixed-methods feasibility study.

BACKGROUND: Recruitment challenges contribute to the paucity of palliative care research with advanced chronic heart failure patients. AIM: To describe the challenges and outline strategies of recruiting advanced chronic heart failure patients. DESIGN: A feasibility study using a pre-post uncontrolled design. SETTING: Advanced chronic heart failure patients were recruited at two nurse-led chronic heart failure disease management clinics in Ireland Results: Of 372 patients screened, 81 were approached, 38 were recruited (46.9% conversion to consent) and 25 completed the intervention. To identify the desired population, a modified version of the European Society of Cardiology definition was used together with modified New York Heart Association inclusion criteria to address inter-study site New York Heart Association classification subjectivity. These modifications substantially increased median monthly numbers of eligible patients approached (from 8 to 20) and median monthly numbers recruited (from 4 to 9). Analysis using a mortality risk calculator demonstrated that recruited patients had a median 1-year mortality risk of 22.7 and confirmed that the modified eligibility criteria successfully identified the population of interest. A statistically significant difference in New York Heart Association classification was found in recruited patients between study sites, but no statistically significant difference was found in selected clinical parameters between these patients. CONCLUSION: Clinically relevant modifications to the European Society of Cardiology definition and strategies to address New York Heart Association subjectivity may help to improve advanced chronic heart failure patient recruitment in clinical settings, thereby helping to address the paucity of palliative care research this population.

Understanding how a palliative-specific patient-reported outcome intervention works to facilitate patient-centred care in advanced heart failure: A qualitative study.

BACKGROUND: Palliative care needs of patients with chronic heart failure are poorly recognised. Policy makers advise a patient-centred approach to holistically assess patients' needs and care goals. Patient-reported outcome measures are proposed to facilitate patient-centred care. AIM: To explore whether and how a palliative care-specific patient-reported outcome intervention involving the Integrated Palliative care Outcome Scale influences patients' experience of patient-centred care in nurse-led chronic heart failure disease management clinics. DESIGN: A feasibility study using a parallel mixed-methods embedded design was undertaken. The qualitative component which examined patients and nurses experience of the intervention is reported here. Semi-structured interviews were conducted and analysed using framework analysis. SETTING/PARTICIPANTS: Eligible patients attended nurse-led chronic heart failure disease management clinics in two tertiary referral centres in Ireland with New York Heart Association functional class II-IV. Nurses who led these clinics were eligible for inclusion. RESULTS: In all, 18 patients and all 4 nurses involved in the nurse-led clinics were interviewed. Three key themes were identified: identification of unmet needs, holistic assessment and patient empowerment. The intervention impacted on processes of care by enabling a shared understanding of patients' symptoms and concerns, facilitating patient-nurse communication by focusing on these unmet needs and empowering patients to become more involved in clinical discussions. CONCLUSION: This Integrated Palliative care Outcome Scale-based intervention empowered patients to become more engaged in the clinical consultation and to highlight their unmet needs. This study adds to the evidence for the mechanism of action of patient-reported outcome measures to improve patient-centred care and will help inform outcome selection for future patient-reported outcome measure research.

Feasibility and acceptability of a patient-reported outcome intervention in chronic heart failure.

Patients with chronic heart failure (CHF) have symptoms and concerns which are inadequately addressed. Patient-reported outcome measures (PROMs) can potentially improve the identification and management of advanced symptoms and palliative concerns. However, these have not been used in CHF. OBJECTIVES: To examine the feasibility and acceptability of using a PROM-the Integrated Palliative care Outcome Scale (IPOS)-together with heart failure nurse education and training to improve the identification and management of symptoms and concerns among patients with CHF. METHODS: A parallel, mixed methods design with an embedded qualitative component was used to examine the feasibility of recruitment, retention, intervention adherence/compliance and follow-up assessment completion (symptom burden, quality of life, psychological well-being). Patient and nurse qualitative semistructured interviews explored intervention and study design feasibility and its acceptability. RESULTS: Conversion to consent was 46.9% (372 screened, 81 approached, 38 recruited). 66% of patient participants completed the IPOS; 6% of IPOS questionnaire items were missing (non-response). Over two-thirds (65.6%) of these missing items related to three patients. No item was consistently missing; appetite was the most frequent missing item (1.4%). 92% of participants who completed the IPOS completed all follow-up assessments (1-2 days, 1-2 weeks and 4-6 weeks post-IPOS completion) with no missing data. The a priori feasibility objectives were met. Patients and nurses reported the intervention and study design feasible and acceptable. CONCLUSIONS: A palliative-specific PROM-based intervention is feasible and acceptable to both patients with CHF and nurses in nurse-led disease management clinics for the purposes of both clinical care and research.

Transitioning high sensitivity cardiac troponin I (hs-cTnI) into routine diagnostic use: More than just a sensitivity issue.

OBJECTIVES: High sensitivity cardiac troponin T and I (hs-cTnT and hs-cTnI) assays show analytical, diagnostic and prognostic improvement over contemporary sensitive cTn assays. However, given the importance of troponin in the diagnosis of myocardial infarction, implementing this test requires rigorous analytical and clinical verification across the total testing pathway. This was the aim of this study. DESIGN AND METHODS: Analytical verification included assessment of critical outlier frequency, for hs-cTnI and cTnI assays. Concordance for paired cTnI and hs-cTnI measurements (n=1096) was verified using 99th percentiles for both genders (cTnI: 30 ng/L, hs-cTnI: 25 ng/L) and for men and women separately (hs-cTnI: M: 34;F: 16 ng/L). Discordant data was correlated with clinical and laboratory information. Diagnosis of Acute Coronary Syndrome (ACS) or Non-ACS was adjudicated by two cardiologists independently. RESULTS: The hs-cTnI assay showed a lower (10-fold) critical outlier rate (0.091%) and more detectable results above the limit of detection (LOD) (23.4%) and 99th percentile (2.4%), compared to cTnI. Analytical concordance between the two assays was high (94.5%) but decreased (91.7%) when gender-specific hs-cTnI cut-offs were used. The hs-cTnI assay gave fewer false negatives (up to 1.0%) but disproportionately more false positives (up to 6.7%) overall, which improved (3.9%) for serial measurements. CONCLUSIONS: Laboratories should analytically and clinically verify hs-cTn assays before use, with attention to performance and the clinical and diagnostic algorithms that support appropriate testing and result interpretation. Work in the pre- and post-analytical phases is necessary to augment the analytical improvement in the new era of troponin testing.

Detection of high-sensitivity troponin in outpatients with stable pulmonary hypertension identifies a subgroup at higher risk of adverse outcomes.

BACKGROUND: The detection of elevations in cardiorenal biomarkers, such as troponins, B-type natriuretic peptides (BNPs), and neutrophil gelatinase-associated lipocalins, are associated with poor outcomes in patients hospitalized with acute heart failure. Less is known about the association of these markers with adverse events in chronic right ventricular dysfunction due to pulmonary hypertension, or whether their measurement may improve risk assessment in the outpatient setting. METHODS AND RESULTS: We performed a cohort study of 108 patients attending the National Pulmonary Hypertension Unit in Dublin, Ireland, from 2007 to 2009. Cox proportional hazards analysis and receiver operating characteristic curves were used to determine predictors of mortality and hospitalization. Death or hospitalization occurred in 50 patients (46.3%) during the median study period of 4.1 years. Independent predictors of mortality were: 1) decreasing 6-minute walk test (6MWT; hazard ratio [HR] 12.8; P < .001); 2) BNP (HR 6.68; P < .001); and 3) highly sensitive troponin (hsTnT; HR 5.48; P < .001). Adjusted hazard analyses remained significant when hsTnT was added to a model with BNP and 6MWT (HR 9.26, 95% CI 3.61-23.79), as did the predictive ability of the model for death and rehospitalization (area under the receiver operating characteristic curve 0.81, 95% CI 0.73-0.90). CONCLUSIONS: Detection of troponin using a highly sensitive assay identifies a pulmonary hypertension subgroup with a poorer prognosis. hsTnT may also be used in a risk prediction model to identify patients at higher risk who may require escalation of targeted pulmonary vasodilator therapies and closer clinical surveillance.

The Brady Bunch? New evidence for nominative determinism in patients' health: retrospective, population based cohort study.

OBJECTIVE: To ascertain whether a name can influence a person's health, by assessing whether people with the surname "Brady" have an increased prevalence of bradycardia. DESIGN: Retrospective, population based cohort study. SETTING: One university teaching hospital in Dublin, Ireland. PARTICIPANTS: People with the surname "Brady" in Dublin, determined through use of an online telephone directory. MAIN OUTCOME MEASURE: Prevalence of participants who had pacemakers inserted for bradycardia between 1 January 2007 and 28 February 2013. RESULTS: 579 (0.36%) of 161,967 people who were listed on the Dublin telephone listings had the surname "Brady." The proportion of pacemaker recipients was significantly higher among Bradys (n=8, 1.38%) than among non-Bradys (n=991, 0.61%; P=0.03). The unadjusted odds ratio (95% confidence interval) for pacemaker implantation among individuals with the surname Brady compared with individuals with other surnames was 2.27 (1.13 to 4.57). CONCLUSIONS: Patients named Brady are at increased risk of needing pacemaker implantation compared with the general population. This finding shows a potential role for nominative determinism in health.

Use of a highly-sensitive cardiac troponin I assay in a screening population for hypertrophic cardiomyopathy: a case-referent study.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) is a genetic condition, and relatives of affected persons may be at risk. Cardiac troponin biomarkers have previously been shown to be elevated in HCM. This study examines the new highly-sensitive cardiac troponin I (hsTnI) assay in a HCM screening population. METHODS: Nested case-control study of consecutive HCM sufferers and their relatives recruited from May 2010 to September 2011. After informed consent, participants provided venous blood samples and clinical and echocardiographic features were recorded. Associations between the natural log (ln) of the contemporary troponin I (cTnI) and hsTnI assays and markers of cardiac hypertrophy were examined. Multiple regression models were fitted to examine the predictive ability of hsTnI for borderline or definite HCM. RESULTS: Of 107 patients, 24 had borderline and 19 had definite changes of HCM. Both TnI assays showed significant, positive correlations with measures of cardiac muscle mass. After age and sex adjustment, the area under the receiver operator characteristic (AUROC) curve for the outcome of HCM was 0.78, 95% CI [0.65, 0.90], for ln(hsTnI), and 0.66, 95% CI [0.51, 0.82], for ln(cTnI) (p=0.11). Including the hsTnI assay in a multiple-adjusted "screening" model for HCM resulted in a non-significant improvement in both the AUROC and integrated discrimination index. CONCLUSIONS: Both cTnI and hsTnI show a graded, positive association with measures of cardiac muscle mass in persons at risk of HCM. Further studies will be required to evaluate the utility of these assays in ECG- and symptom-based identification of HCM in at-risk families.

A Comparison of Traditional and Novel Definitions (RIFLE, AKIN, and KDIGO) of Acute Kidney Injury for the Prediction of Outcomes in Acute Decompensated Heart Failure.

AIMS: To determine if newer criteria for diagnosing and staging acute kidney injury (AKI) during heart failure (HF) admission are more predictive of clinical outcomes at 30 days and 1 year than the traditional worsening renal function (WRF) definition. METHODS: We analyzed prospectively collected clinical data on 637 HF admissions with 30-day and 1-year follow-up. The incidence, stages, and outcomes of AKI were determined using the following four definitions: KDIGO, RIFLE, AKIN, and WRF (serum creatinine rise ≥0.3 mg/dl). Receiver operating curves were used to compare the predictive ability of each AKI definition for the occurrence of adverse outcomes (death, rehospitalization, dialysis). RESULTS: AKI by any definition occurred in 38.3% (244/637) of cases and was associated with an increased incidence of 30-day (32.3 vs. 6.9%, χ(2) = 70.1; p < 0.001) and 1-year adverse outcomes (67.5 vs. 31.0%, χ(2) = 81.4; p < 0.001). Most importantly, there was a stepwise increase in primary outcome with increasing stages of AKI severity using RIFLE, KDIGO, or AKIN (p < 0.001). In direct comparison, there were only small differences in predictive abilities between RIFLE and KDIGO and WRF concerning clinical outcomes at 30 days (AUC 0.76 and 0.74 vs. 0.72, χ(2) = 5.6; p = 0.02) as well as for KDIGO and WRF at 1 year (AUC 0.67 vs. 0.65, χ(2) = 4.8; p = 0.03). CONCLUSION: During admission for HF, the benefits of using newer AKI classification systems (RIFLE, AKIN, KDIGO) lie with the ability to identify those patients with more severe degrees of AKI who will go on to experience adverse events at 30 days and 1 year. The differences in terms of predictive abilities were only marginal.

Family-based cardiac screening in relatives of victims of sudden arrhythmic death syndrome.

AIMS: Sudden arrhythmic death syndrome (SADS) occurs when a person suffers a sudden, unexpected death, with no cause found at postmortem examination. We aimed to describe the cardiac screening outcomes in a population of relatives of SADS victims METHODS AND RESULTS: Prospective and retrospective cohort study of consecutive families attending the Family Heart Screening clinic at the Mater Misericordiae Hospital in Dublin, Ireland, from January 2007 to September 2011. Family members of SADS victims underwent a standard screening protocol. Adjunct clinical and postmortem information was sought on the proband. Families who had an existing diagnosis, or where the proband had epilepsy, were excluded. Of 115 families identified, 73 were found to fit inclusion criteria and were retained for analysis, with data available on 262 relatives. Over half of the screened family members were female, and the mean age was 38.6 years (standard deviation 15.6). In 22 of 73 families (30%), and 36 of 262 family members (13.7%), a potentially inheritable cause of SADS was detected. Of the population screened, 32 patients (12.2%) were treated with medication, and 5 (1.9%) have received implantable cardiac defibrillators. Of the five families with long QT syndrome (LQTS) who had a pathogenic gene mutation identified, three carried two such mutations. CONCLUSION: In keeping with international estimates, 30% of families of SADS victims were found to have a potentially inherited cardiac disease. The most common positive finding was LQTS. Advances in postmortem standards and genetic studies may assist in achieving more diagnoses in these families.

Family-based associations in measures of psychological distress and quality of life in a cardiac screening clinic for inheritable cardiac diseases: a cross-sectional study.

BACKGROUND: Family-based cardiac screening programmes for persons at risk for genetic cardiac diseases are now recommended. However, the psychological wellbeing and health related quality of life (QoL) of such screened patients is poorly understood, especially in younger patients. We sought to examine wellbeing and QoL in a representative group of adults aged 16 and over in a dedicated family cardiac screening clinic. METHODS: Prospective survey of consecutive consenting patients attending a cardiac screening clinic, over a 12 month period. Data were collected using two health measurement tools: the Short Form 12 (version 2) and the Hospital Anxiety and Depression Scale (HADS), along with baseline demographic and screening visit-related data. The HADS and SF-12v.2 outcomes were compared by age group. Associations with a higher HADS score were examined using logistic regression, with multi-level modelling used to account for the family-based structure of the data. RESULTS: There was a study response rate of 86.6%, with n=334 patients providing valid HADS data (valid response rate 79.5%), and data on n=316 retained for analysis. One-fifth of patients were aged under 25 (n=61). Younger patients were less likely than older to describe significant depression on their HADS scale (p<0.0001), although there were overall no difference between the prevalence of a significant HADS score between the younger and older age groups (18.0% vs 20.0%, p=0.73). Significant positive associates of a higher HADS score were having lower educational attainment, being single or separated, and being closely related to the family proband. Between-family variance in anxiety and depression scores was greater than within-family variance. CONCLUSIONS: High levels of anxiety were seen amongst patients attending a family-based cardiac screening clinic.Younger patients also had high rates of clinically significant anxiety. Higher levels of anxiety and depression tends to run in families, and this has implications for family screening and intervention programmes.

Natural history, management, and outcomes of peripartum cardiomyopathy: an Irish single-center cohort study.

AIM: To describe the natural history, management and outcomes of peripartum cardiomyopathy (PPCM) in an unselected Northern European population. METHODS: A retrospective single-center observational study was performed at a tertiary referral heart failure and transplantation unit. Outcomes measured were baseline demographics, clinical presentation, course, and treatment. Echocardiographic findings were compared at baseline, 2 months, and 6 months. RESULTS: Twelve cases of PPCM were identified between 2002 and 2008. Mean age was 34.7 years. Nine patients were multiparous and nine had preeclampsia. Ten patients presented in the first week postpartum. Two patients required inotropic support. Mean ejection fraction (EF) at presentation was 27% (SD = 8%) which improved to 47% (SD = 13%) at 6 months. At this time, 10 patients were asymptomatic and 6 had recovered normal cardiac function. Left ventricular (LV) function improved but did not reach normal limits in five cases. One case with persistent severe LV dysfunction required cardiac transplantation. One patient suffered an arrhythmic death several years after the 6 months follow-up period. CONCLUSIONS: PPCM is a rare condition. With appropriate therapy, a good clinical outcome is common but not universal. Continued deterioration requiring ventricular support and cardiac transplantation can occur. In our cohort, older maternal age, multiparity, and preeclampsia appeared to be risk factors.

Cost implications of defibrillator lead failures.

AIMS: The prevalence of lead failures is increasing with a growing population of implantable cardioverter defibrillator (ICD) recipients. The cost of managing defibrillator lead failures requires investigation. METHODS AND RESULTS: A retrospective cohort study of patients requiring lead replacement for defibrillator lead failure was performed. Details pertaining to admissions were recorded. The cost per lead replacement was determined. Twenty-three patients {mean age [standard deviation (SD); range] = 56 (17; 18-83) years; 87% male} underwent lead replacement at a mean (SD; range) interval from implant of 3.0 (1.8; 0.9-9.0) years. The median (SD; range) length of hospital stay was 4.5 (8.6; 1-43) days. Procedure-related complications were recorded for three (13%) patients. Thirty days and 1-year mortality were 0 and 4% (1 of 23). The median (SD; range) cost per lead replacement was €7660 (€10 964; €1472-39 663). Bed day costs accounted for 54% of overall costs. Extraction of the failed lead by manual traction at time of lead replacement did not significantly increase costs. The median (SD; range) cost of lead replacement was higher in patients receiving a new ICD generator (n= 6), compared with patients retaining existing generators (n= 17): €23 394 (€5026; €17 266-31 245) vs. €4470 (€9080; €1472-39 663); P= 0.005. The median (SD; range) cost of lead replacement among patients who remained in hospital pending lead replacement (n= 16) was higher than for patients who underwent replacement on an emergent outpatient basis (n= 7): €8508 (€11 920; €1472-39 663) vs. €4372 (€7256; €1555-20 478); however, this observation was not statistically significant, P= 0.21. CONCLUSIONS: Defibrillator lead failures incur significant cost and are likely to undermine overall cost effectiveness of ICDs. Cost-effectiveness analyses of device therapy should include costs related to such complications.

Increased incidence of QT interval prolongation in a population receiving lower doses of methadone maintenance therapy.

AIMS: The aim of this study was to investigate the frequency of corrected QT interval (QTc) prolongation in a methadone maintenance therapy (MMT) population, and to examine potential associations between this QTc interval and methadone dose as well as concurrent use of opiates, cocaine and benzodiazepines. DESIGN: Cross-sectional study of patients attending a specialist drug treatment clinic from July 2008 to January 2009. SETTING: Single-centre inner-city specialist drug treatment clinic, Ireland. PARTICIPANTS: A total of 180 patients on stable MMT attending for daily methadone doses, over a 6-month period, where a total of 376 patients were attending during the study period. MEASUREMENTS: All patients agreeing to participate in the study underwent 12-lead electrocardiograms and QTc analysis, as well as analysis of urine toxicology screen results for opiates, benzodiazepines and cocaine. ECGs were carried out prior to methadone dose being received, regardless of time of day (trough ECG). FINDINGS: The average age was 32.6 ± 7.1 years, with mean [standard deviation (SD)] methadone dose 80.4 ± 27.5 mg. The mean (SD) QTc was 420.9 ± 21.1 ms, range 368-495 ms. Patients who had a positive toxicology screen for opiates were receiving significantly lower doses of methadone (77.8 ± 23.5 mg versus 85.0 ± 21.4 mg, P = 0.04). No significant association was noted between QTc interval prolongation and presence of cocaine metabolites in the urine (P = 0.13) or methadone dose (P = 0.33). 8.8% of patients had evidence of prolonged QTc interval (8.3% male QTc ≥ 450 ms and 0.5% female QTc ≥ 470 ms), with 11.1% (n = 20) having QTc intervals > 450 ms. CONCLUSIONS: Drug-induced corrected QT interval prolongation is evident (ranging from 8.8-11.1%, depending on definition applied) in patients receiving relatively low daily doses of methadone therapy, with no evidence of a dose-response relationship. The presence of cocaine metabolites in urine does not appear to be associated with increased corrected QT interval. Increased awareness of cardiac safety guidelines, including relevant clinical and family history, baseline and trough dose ECG monitoring, should be incorporated into methadone maintenance therapy protocols.