Screening tools for the detection of clinically silent cardiac sarcoidosis

BACKGROUND

clinically silent cardiac sarcoidosis (CS) may be associated with adverse outcomes, hence the rationale for screening patients with extracardiac sarcoidosis. The optimal screening strategy has not been clearly defined.

METHODS

patients with extra-cardiac sarcoidosis were prospectively included and underwent screening consisting of symptom history, electrocardiography (ECG), transthoracic echocardiogram, Holter, and signal-averaged ECG (SAECG). Cardiac magnetic resonance (CMR) was performed in all patients. Clinically silent CS was defined as CMR demonstrating late gadolinium enhancement (LGE) in a pattern compatible with CS according to a majority of independent and blinded CMR experts. Significant cardiac involvement was defined as the presence of LGE ≥6% and/or a positive fluorodeoxyglucose-positron emission tomography.

RESULTS

among the 129 patients included, clinically silent CS was diagnosed in 29/129 (22.5%), and 19/129 patients (14.7%) were classified as CS with significant cardiac involvement. There was a strong association between hypertension and CS (p < 0.05). Individual screening tools provided low diagnostic yield; however, combination of tests performed better, for example, a normal Holter and a normal SAECG had negative predictive values of 91.7%. We found consistently better diagnostic accuracy for the detection of CS with significant cardiac involvement.

CONCLUSION

clinically silent CS and CS with significant cardiac involvement were found in 22.5% and 14.7% of patients with extra-cardiac sarcoidosis. The association with hypertension raises the possibility that some cases of hypertensive cardiomyopathy may be mistaken for CS. Screening with readily available tools, for example Holter and SAECG, may help identifying patients without CS where additional CMR is not needed.

Incidence of Atrial Fibrillation as the Initial Manifestation of Cardiac Sarcoidosis: Insights From a Catheter Ablation Registry

Background

Cardiac sarcoidosis (CS) is a rare form of arrhythmogenic cardiomyopathy; a delayed diagnosis can lead to significant consequences. Patients with clinically manifest CS often have minimal extracardiac involvement and thus frequently present initially to cardiology. Indeed, certain specific arrhythmic scenarios should trigger investigations for undiagnosed CS. Atrial fibrillation (AF) has been described as one of the presenting features of CS; however, the incidence of this presentation is not known.

Methods

At our institution, cardiac computerized tomography is routinely performed prior to catheter ablation for AF. Noncardiac incidental findings are described by radiologists and are followed-up by interval investigations. We systematically reviewed noncardiac reports from 1574 consecutive patients in our prospective AF ablation registry. Specifically, we used text-scraping techniques to search on the following keywords: "adenopathy" and "sarcoidosis." Detailed chart review of identified cases was then performed to evaluate results of interval investigations and assess long-term outcomes.

Results

Twenty of 1574 patients (1.3%) had noncardiac reports containing "adenopathy" and/or "sarcoidosis." After interval imaging and a follow-up period averaging 60 ± 35 months, only 2 patients of 1574 (0.13%) were diagnosed with CS. Four of 20 (20%) had a previous history of extracardiac sarcoidosis, and another 1 of 20 (5%) was subsequently diagnosed with extracardiac sarcoidosis. However, none of these 5 patients had evidence of cardiac involvement.

Conclusions

CS is a rare finding among patients undergoing a first-time AF ablation. Our findings suggest that AF is an uncommon initial presentation of CS. Thus, investigations for CS in patients with AF are not warranted routinely, unless additional suggestive clinical features are present.

A Randomized Trial of Lenient Versus Strict Arm Instruction Post Cardiac Device Surgery (LENIENT)

BACKGROUND

Arm restriction after cardiac implantable electronic device (CIED) placement is common practice despite minimal supporting evidence. Patients receive a range of restriction recommendations of variable durations with the goal of reducing complications such as wound dehiscence, infection, lead dislodgement, or hematoma formation. These movement limitations can lead to emotional stress and anxiety, complications such as frozen shoulder, and upper extremity venous thrombosis due to immobilization. There are no published clinical trials assessing the benefits and risks of arm restrictions post-CIED implant.

OBJECTIVES

The randomized trial of lenient vs strict arm and activity instruction post-CIED surgery (LENIENT trial; NCT04915261) is a single center nonblinded randomized prospective study designed to evaluate lenient compared to restrictive post-CIED care instructions. We hypothesize that there will be no significant difference in complications between the arms.

METHODS/DESIGN

All patients receiving a de novo CIED or those with upgrades and revisions requiring a new lead implant will be enrolled. Subjects are enrolled in a nonblinded randomized prospective trial with 6 randomly assigned 8-month periods, during which either a lenient or restrictive postoperative activity instructions will be given to all patients. Postoperative instructions are given at the time of discharge and further reinforced by recurrent interactive voice recognition (IVR) phone calls, text messages and emails. The requirement for individual consent has been waived. The primary end point is a composite of (1) lead dislodgement, (2) frozen shoulder, (3) upper extremity venous thrombosis, (4) clinically significant hematoma, and (5) infection occurring within 52 weeks of index surgery. The study is a noninferiority trial with a sample size of 1,250 per group.

DISCUSSION

This is the first large randomized clinical trial designed to establish an evidence-based postoperative standard of care for patients undergoing CIED implantation. This will improve the quality of care provided to patients and help guide implanting physicians providing postoperative care instructions.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04915261.

Management of ventricular tachycardia in patients with cardiac sarcoidosis

Sarcoidosis is a multisystem granulomatous disease with 2 different phases (inflammation and scar). In the current era of targeted use of implantable cardioverter-defibrillators and modern heart failure therapy, recent data indicate the prognosis of cardiac sarcoidosis (CS) is much improved, and hence more patients are presenting with recurrent ventricular tachycardia (VT). This review highlights our current understanding of the pathophysiology and management of ventricular arrhythmias in CS with the major focus on indications, techniques, and outcomes of ablation. It is likely macroreentry phenomena around areas of fibrosis is the most frequent mechanism of ventricular arrhythmia in CS. It is also possible that inflammation may play a role in initiating reentry with ventricular ectopy in CS patients, or by slowing conduction in diseased tissue. The best available data would suggest annual rates of VT of perhaps 1%-2% and 10%-15% in patients with initially clinically silent and clinically manifest disease, respectively. Current guidelines recommend a stepwise approach to VT management. The first suggested step is treatment with immunosuppression if there is evidence of active inflammation. Antiarrhythmic medications are often started at the same time, with catheter ablation considered if VT cannot be controlled. Activation and entrainment mapping and ablation are favored in the setting of hemodynamically tolerated VT. Substrate ablation targets areas of abnormal electrogram and favorable pace mapping using linear and/or cluster lesion sets with the goal of abolishing critical isthmuses and/or blocking VT exit sites. Epicardial mapping ablation is required in 20%-35% of cases. In general, more morphologies of VT are induced (often 3-4) and subsequent outcomes (recurrence rates 40%-50%) are less favorable than in other forms of nonischemic cardiomyopathy. The prognosis of CS is much improved and, as a result, more patients are developing VT during follow-up. Likely principally related to the complex disease substrate, VT ablation is technically challenging, with moderate outcomes, and much remains to be learned.

Canadian Registry of Electronic Device Outcomes: remote monitoring outcomes in the Abbott battery performance alert-a multicentre cohort

AIMS

Cardiac implantable electronic devices with device advisories have the potential of device malfunction. Remote monitoring (RM) of devices has been suggested to allow the identification of abnormal device performance and permit early intervention. We sought to describe the outcomes of patients with and without RM in devices subject to the Abbott Premature Battery Depletion (PBD) advisory with data from a Canadian registry.

METHODS AND RESULTS

Patients with an Abbott device subject to the PBD advisory from nine implantable cardioverter defibrillator (ICD) implanting centres in Canada were included in the registry. The use of RM was identified from baseline and follow-up data in the registry. The primary outcome was detection of PBD and all-cause mortality. A total of 2666 patients were identified with a device subject to the advisory. In all, 1687 patients (63.2%) had RM at baseline. There were 487 deaths during follow-up. At a mean follow-up of 5.7 ± 0.7 years, mortality was higher in those without a remote monitor compared with RM at baseline (24.7% vs. 14.5%; P < 0.001). Pre-mature battery depletion was identified in 36 patients (2.1%) with RM vs. 7 (0.7%) without RM (P = 0.004). Time to battery replacement was significantly reduced in patients on RM (median 5 vs. 13 days, P = 0.001).

CONCLUSION

The use of RM in patients with ICD and cardiac resynchronization therapy under advisory improved detection of PBD, time to device replacement, and was associated with a reduction in all-cause mortality. The factors influencing the association with mortality are unknown and deserve further study.

Canadian Registry of Electronic Device Outcomes (CREDO): The Abbott ICD Premature Battery Depletion Advisory, a Multicentre Cohort Study

Background

Premature or rapid battery depletion may compromise the performance and reliability of an implantable cardioverter defibrillator (ICD), potentially resulting in harm or death to patients. We sought to describe the outcomes and clinical management of devices included in the Abbott ICD Premature Battery Depletion Advisory, using data from a Canadian registry.

Methods

This prospective observational study includes patients with an Abbott device subject to the advisory, from 9 centres in Canada. The incidence and outcomes related to device revision owing to premature battery depletion were identified and adjudicated by a committee.

Results

There were 2678 patients enrolled with a device subject to the advisory. Devices were implanted between 2010 and 2017; follow-up time was 5.7 ± 0.7 years. Device revision occurred in 222 patients (8.3%). Revision for premature battery depletion occurred in 43 patients (1.6%). Devices were revised at physician discretion on notice of the advisory in 16 patients (0.6%), and at patient request in 5 patients (0.2%). A total of 63 (2.4%) devices reached routine end of battery life. A further 95 (3.5%) patients underwent revision for other reasons. There were no reported major complications or adverse events with device revision owing to the advisory. There were no deaths attributed to premature battery depletion.

Conclusions

The rate of premature battery depletion associated with the Abbott ICD Premature Battery Depletion Advisory is low. There were no clinically adverse events identified that were associated with the battery performance of devices under advisory.

FLT-PET for the assessment of systemic sarcoidosis including cardiac and CNS involvement: a prospective study with comparison to FDG-PET

BACKGROUND

2-deoxy-2-[18F]fluoro-D-glucose's (FDG) biodistribution limits the evaluation of cardiac sarcoidosis (CS) and neurosarcoidosis (NS). While protocols for cardiac suppression exist, they can be inconvenient for patients and lead to incomplete cardiac suppression in many cases. Furthermore, FDG PET is limited in the detection of neurosarcoidosis due to an inability to suppress high level of physiological uptake within the brain. 3'-deoxy-3'-[¹⁸F]fluorothymidine (FLT) has been shown to accumulate in sarcoidosis lesions and this tracer lacks significant physiological myocardial and brain uptake, suggesting that this tracer may be useful for the assessment of sarcoidosis, including CS and NS, without the need for patient preparation. This prospective pilot study examined the performance of FLT vs FDG PET for systemic sarcoidosis, including cardiac and neural involvement.

MATERIALS AND METHODS

Fourteen subjects with sarcoidosis were prospectively recruited and imaged with FDG- and FLT-PET. Two blinded, experienced readers independently reviewed the FLT-PET and FDG-PET images. Lesion distribution was compared between FLT and FDG. Agreement between FLT- and FDG-PET was determined using Cohen's kappa and the intra-class correlation coefficient. Inter-observer variability of FLT and FDG-PET was assessed.

RESULTS

Twelve subjects had CS as per Heart Rhythm Society criteria and 1 had NS. FLT-PET was positive in 12 (86%), and FDG-PET in 11 (79%), with cardiac uptake present in 6 (50%) and 7 (58%) of subjects with CS, respectively. The subject with NS demonstrated uptake on both FLT and FDG-PET, with more lesions on FLT. There were no significant differences in the anatomical distribution of lesions between FLT and FDG. SUVs were significantly (p < 0.001) higher for FDG than FLT (5.8 ± 3.0 vs 2.3 ± 1.1, respectively), but not (p = 0.90) after adjusting for blood pool activity (2.8 ± 1.4 vs 2.8 ± 1.1, respectively). Agreement between FLT- and FDG-PET was good to excellent for the diagnosis of sarcoidosis, lung involvement, CS, and NS (κ = 0.76, 0.69, 0.86, and 1.0, respectively). Inter-observer agreement for FLT was excellent for diagnosing sarcoidosis, CS and NS (κ = 0.81, 0.85, and 1.0, respectively) and comparable to that of FDG.

CONCLUSIONS

FLT-PET may be useful for the assessment of systemic sarcoidosis, as well as cardiac and neural involvement.

Cardiac Sarcoidosis multi-center randomized controlled trial (CHASM CS- RCT)

Approximately 5% of patients with sarcoidosis have clinically manifest cardiac involvement. Clinical features of Cardiac Sarcoidosis are dependent on the location, extent, and activity of the disease. First line therapy is usually with prednisone and this is recommended based on clinician experience, expert opinion and small observational cohorts. There are no published clinical trials in cardiac sarcoidosis and multiple experts in the field have called for randomized clinical trials to answer important patient care questions. Corticosteroid are associated with multiple adverse effects including hypertension, diabetes, weight gain, osteoporosis, and increased risk of infections. In contrast Methotrexate is generally well tolerated and is increasingly used in other forms of sarcoidosis.

OBJECTIVES

The Cardiac Sarcoidosis Multi-Center Randomized Controlled Trial (CHASM CS-RCT; NCT03593759) is a multicenter randomized controlled trial designed to evaluate the optimal initial treatment strategy for patients with active cardiac sarcoidosis. We hypothesize that (1) a low dose prednisone/methotrexate combination will have non-inferior efficacy to standard dose prednisone and that (2) the low dose prednisone/ methotrexate combination will result in significantly better quality of life than standard dose prednisone, as a result of reduced burden of side effects.

METHODS/DESIGN

Eligible study subjects will have active clinically manifest cardiac sarcoidosis presenting with one or more of the following clinical findings: advanced conduction system disease, significant sinus node dysfunction, non-sustained or sustained ventricular arrhythmia, left ventricular dysfunction or right ventricular dysfunction. Subjects will be randomized in a 1:1 ratio to prednisone 0.5 mg/kg/day for 6 months (maximum dose 30 mg daily) OR to prednisone 20 mg daily for 1 month, then 10 mg daily for 1 month, then 5 mg daily for one month then stop AND methotrexate 15-20 mg once weekly for 6 months. The primary endpoint is summed perfusion rest score on 6-month PET (blinded core-lab review). The summed perfusion rest score is measure of myocardial fibrosis/scar. The design is non-inferiority with a sample size of 97 per group.

DISCUSSION

Given the multiorgan system potential adverse side effects of prednisone, proving noninferiority of an alternate regimen would be sufficient to make the alternative compare favorably to standard dose steroids. This is the first ever clinical trial in cardiac sarcoidosis and thus in addition to the listed goals of the trial, we will also establish a multi-center, multinational cardiac sarcoidosis clinical trials network. Such a collaborative infrastructure will enable a new era of high quality data to guide physicians when treating cardiac sarcoidosis patients.

Mortality Risk Increases With Clustered Ventricular Arrhythmias in Patients With Implantable Cardioverter-Defibrillators

OBJECTIVES

This study sought to examine the adverse prognosis associated with ventricular arrhythmia clusters that falls outside the current electrical storm definition.

BACKGROUND

Electrical storm is most frequently defined as a cluster of ≥3 episodes of ventricular arrhythmia (VA) in a 24-h period. This definition has been associated with adverse cardiovascular outcomes and mortality, but the effect of lesser and greater clustering of arrhythmias has not been described.

METHODS

Among all patients in the Resynchronization in Ambulatory Heart Failure trial, 14,515 implantable cardioverter-defibrillator-detected events with data available were rigorously adjudicated in blinded fashion. Arrhythmia incidence was examined for clustering, defined as 2 or more VA events occurring within 3 months. The prognostic importance of clustering was analyzed by varying the cluster length and number of events used to define a cluster. Mortality rates of groups with clustered arrhythmias were compared to patients with no arrhythmia or with unclustered arrhythmia.

RESULTS

The trial included 1,764 patients, among whom 465 patients had two or more VA episodes within 3 months, whereas 406 had unclustered arrhythmias. Compared to patients with no arrhythmia, patients experiencing unclustered VA had increased risk of death (hazard ratio [HR]: 1.45; 95% confidence interval [CI]: 1.09 to 1.93; p = 0.011), whereas the risk was even higher in patients with clustered arrhythmia (HR: 2.68; 95% CI: 2.13 to 3.36; p < 0.0001). Mortality risk increased with higher VA burden (number of VAs in a cluster) and shorter cluster length. This was observed in all groups tested, including the cluster with the least VA burden in the longest cluster length tested (2 VA episodes occurring within 3 months) (mortality HR: 2.85; 95% CI: 1.95 to 4.17; p < 0.0001). Although clustered arrhythmias terminated with antitachycardia pacing were associated with increased mortality, clusters terminated with implantable cardioverter-defibrillator shocks were associated with still higher mortality risk.

CONCLUSIONS

Significant adverse prognostic association of clustered VAs is observable with even 2 VA events within 3 months and increases with higher cluster density.

P2853Contemporary reporting of acute complications from implantable cardioverter defibrillator surgery

Background

Defibrillator placement carries an inherent risk to the patient. Traditionally, major adverse events defined as cardiac arrest, tamponnade, pneumothorax, infection requiring re-operation, MI and CVA within 30 days are reported to occur between 3 and 4%. Minor complications such as heamatomae or lead dislodgement are reported between 8 and 13%. Novel lead technologies, protocolised programming and reduced use of Heparin bridging have been reported to reduce adverse outcomes. However, patients are still typically monitored in hospital for 24 hours to mitigate these risks. There is little evidence that discharge delay is effective yet incurs significant additional costs.

Purpose

We sought to evaluate the frequency and timing of adverse events relating to defibrillator surgery (ICD and CRT-D) at a large Canadian tertiary care center (UOHI).

Methods

We retrospectively reviewed all patients who received a defibrillator placed from 1st April 2013 to 31st March 2018 inclusive. Patient comorbidities were extracted from the hospital electronic medical record (EMR) system. Device related information and complications were extracted from UOHI PaceartTM system and EMR and cross referenced with physician remuneration databases.

Results

A total of 2221 procedures were performed on 2153 patients (78% male, mean age 65 years). The majority (60%) of defibrillator implants were de novo, with 884 (40%) pulse generator replacements/ upgrades and 868 (39%) defibrillators had CRT capability. Patients were routinely discharged within 24 hours of ICD surgery. Post-operative follow up ≥30 days was complete in 97% patients. Major adverse events occurred within 30 days in 9 patients (0.4%); 9 (100%) were infection requiring re-operation. An additional 32 patients (1.5%) required repeat interventions or readmission within 30 days of implant, most commonly due to lead dislodgement. Only 2 patients required readmission within 24 hours of surgery (0.1%). All procedure-related adverse events during clinical follow up (≤5 years) were 131 (5.9%) occurring in 122 patients. There were no apparent predictors of adverse events in this cohort.

Conclusion(s)

Contemporary risks to patients undergoing defibrillator surgery are considerably lower than that reported in 2010. The risk of infection appears constant despite increased antibiosis. Patients receiving an ICD or CRT-D can safely be discharged within 24 hours if no complications are apparent.

Acknowledgement/Funding

None

P6546Canadian Registry of Electronic Device Outcomes (CREDO): remote monitoring outcomes in the abbott battery performance alert, a multicentre cohort

Background

Cardiac implantable electronic devices have been known to have lead and device malfunctions leading to advisories. Increased use of remote monitoring of devices has been suggested to allow the identification of abnormal device performance and allow early intervention. We sought to describe the outcomes of patients with and without remote monitoring of in devices in the Abbott Premature Battery Depletion advisory with data from a Canadian registry

Methods

Patients with an Abbott device subject to the Battery Performance Alert Advisory from nine ICD implanting centres in Canada were included in the registry. The use of remote monitoring was identified from baseline and followup data in the registry. The primary outcome was detection of premature battery depletion and all cause mortality.

Results

2679 patents were identified with a device subject to the advisory. Devices were implanted between 2010 and 2017. 1716 patients (64%) had remote monitoring at baseline with this increasing to 83.7% at followup at 12 months. Premature battery depletion occurred in 43 patients (1.6%). Discovery of premature battery depletion was detected by remote monitoring in 70% of patients. There were 492 deaths during the follow up. Mortality was higher in those without a remote monitor compared to those with a remote monitor at follow-up and remote monitor at baseline and follow-up (11.3%, 2.6% versus 6.1% respectively; p=0.0186). There were no deaths attributed to premature battery depletion

Conclusion

The use of remote monitoring in patients with ICD and CRT under advisory reliably detected device failure and was associated with a reduction in all-cause mortality.

Safety and long-term effectiveness of paroxysmal atrial fibrillation ablation with a contact force-sensing catheter: real-world experience from a prospective, multicentre observational cohort registry

Aims

Real-time contact force (CF)-sensing radiofrequency ablation catheter for treatment of paroxysmal atrial fibrillation (PAF) allows optimization of electrode-tissue contact, which correlates with long-term success. This prospective, multicentre observational registry assessed the real-world clinical effectiveness of a CF-sensing catheter for ablation of drug-refractory PAF.

Methods and results

Patients were followed-up at 3, 6, and 12 months after ablation. Outcome measures included isolation of targeted pulmonary veins (PVs) confirmed by entrance block (acute success), patient-reported freedom from symptomatic atrial fibrillation (AF) at 12 months (long-term effectiveness), Atrial Fibrillation Effect on Quality-of-life scores at 6 and 12 months, and incidence of predefined procedural complications. The registry enrolled 261 PAF patients (mean age 58.8 ± 11.3 years; 70.7% men; 91.7% Caucasian). Acute PV isolation was reported in 98.8% of patients [95% confidence interval (CI): 96.4-99.7%], and 12-month success for freedom from symptomatic AF was 75.7% (95% CI: 69.7-80.7%). Average CF for the evaluable cohort was 16.4 ± 3.9 g. There was a significant correlation between long-term effectiveness and stability of CF use [percentage of time CF was within investigator-selected working range; odds ratio (95% Wald CI), 1.0 (1.00-1.1); P = 0.030]. Average CF did not correlate with 12-month success. Clinically meaningful quality of life (QoL) improvements were observed at 6 and 12 months. Primary adverse events occurred in 2.7% patients.

Conclusion

This observational registry showed that PAF ablation with a CF-sensing catheter had high acute success rates, favourable 12-month outcomes, and a good safety profile. Patients' QoL improved significantly. Long-term effectiveness significantly correlated with stable CF with adequate catheter-tissue contact (NCT01677052).

Effect of Baseline Antiarrhythmic Drug on Outcomes With Ablation in Ischemic Ventricular Tachycardia: A VANISH Substudy (Ventricular Tachycardia Ablation Versus Escalated Antiarrhythmic Drug Therapy in Ischemic Heart Disease)

BACKGROUND

The VANISH trial (Ventricular Tachycardia Ablation Versus Escalated Antiarrhythmic Drug Therapy in Ischemic Heart Disease) compared the effectiveness of escalated antiarrhythmic drug therapy to catheter ablation in patients with prior myocardial infarction, an implanted defibrillator, and ventricular tachycardia (VT). The effectiveness of these interventions in patients on sotalol versus amiodarone was compared.

METHODS AND RESULTS

Analysis was conducted based on whether patients had recurrent VT, despite amiodarone (amio-refractory) or nonamiodarone drugs (sotalol-refractory). Outcomes included death, VT storm, appropriate implantable cardioverter defibrillator shock, and any ventricular arrhythmia. At baseline, 169 (65.2%) were amio-refractory, and 90 (34.7%) were sotalol-refractory (1 patient on procainamide rather than sotalol). Amio-refractory patients had more renal insufficiency (23.7% versus 10%; P=0.0008), worse New York Heart Association class (82.3% II/III versus 65.5%; P=0.0003), and lower ejection fraction (29±9.7% versus 35.2±11%; P<0.0001). Within the amio-refractory group, ablation resulted in reduction of any ventricular arrhythmia compared with escalated drug therapy (hazard ratio, 0.53; 95% confidence interval, 0.31-0.9), P=0.020). Sotalol-refractory patients had trends toward higher mortality and VT storm with ablation, with no effect on implantable cardioverter defibrillator shocks. Within the escalated drug therapy arm, amio-refractory patients had a higher rate of the composite outcome (hazard ratio, 1.94; 95% confidence interval, 1.14-3.29; P=0.0144) and a trend to higher mortality (hazard ratio, 2.40; 95% confidence interval, 0.93-6.22; P=0.07), whereas mortality was not different between amio- and sotalol-refractory patients within the ablation treatment group.

CONCLUSIONS

Patients with amio-refractory VT have a higher rate of ventricular arrhythmia and mortality than those with sotalol-refractory VT and derive greater benefit of catheter ablation than for patients with sotalol-refractory VT who are switched to amiodarone.

CLINICAL TRIAL REGISTRATION

URL: https://clinicaltrials.gov. Unique identifier: NCT00905853.

Spontaneous coronary artery dissection in cardiac sarcoidosis

Cardiac sarcoidosis (CS) is increasingly recognized as a cause of diverse cardiac manifestations. Spontaneous coronary artery dissection (SCAD) has emerged as an important cause of acute coronary syndrome especially among young females. The prevalence of sarcoidosis in the causal spectrum of SCAD has not been described before but sarcoidosis is cited as a potential yet rare cause of SCAD. We aimed to examine the frequency and characteristics of SCAD in CS. Searching two prospective CS registries with 481 CS patients, we found only one case of manifest SCAD. She is a 61-year-old female previously diagnosed with endomyocardial biopsy confirmed CS. She presented with chest pain and elevated troponin. Coronary angiogram revealed two-vessel SCAD. Fluorodeoxyglucose positron emission tomography scan showed likely reactivation of CS. The patient was treated with dual antiplatelet therapy and immunosuppression. Repeat angiogram showed complete resolution of the coronary lesions.

Canadian Registry of Implantable Electronic Device Outcomes: Surveillance of High-Voltage Leads

BACKGROUND

Cardiac implantable electrical devices (CIEDs) are subject to advisories and complications that can result in morbidity and mortality for patients; there is currently no system in Canada to track these.

METHODS

This was a multicenter, prospective cohort study conducted at 5 centers to determine feasibility. Patients with a de novo high-voltage (HV) lead implantation were included and followed for a minimum of 1 year.

RESULTS

There were 611 leads enrolled into the registry over 18 months. The mean age was 62.4 ± 12.8 years; 144 (23.6%) women were enrolled. The indication for lead implantation was for primary prevention in 65.5%. There were 497 (82.1%) de novo devices (single chamber: 54.5%, dual chamber: 20.5%, cardiac resynchronization therapy [CRT] 25.0%); the remainder of the procedures was a system revision for either upgrade (8.1%) or lead revision (9.8%). The lead revision rate at 1 year was 3.4%, with the primary reason being lead dislodgements. Mortality rate was 3.8% at 1 year. The rate of any device-related complication was 2.0% at 30 days, with the highest rate in CRT implants (4.9%, P = 0.0105). At 1 year, the complication rate was 4.5%, with no significant difference among device types.

CONCLUSIONS

This study demonstrates that device surveillance is feasible and highlights (1) the need for CIED surveillance to track device-related complications, (2) the scope of this should be larger, and (3) mandatory participation should be considered. This system could predict CIEDs that may be susceptible to higher than usual rates of failure, mitigating adverse outcomes in patients.

Differentiating Ventricular From Supraventricular Arrhythmias Using the Postpacing Interval After Failed Antitachycardia Pacing

BACKGROUND

Implantable cardioverter defibrillator arrhythmia discrimination algorithms often are unable to discriminate ventricular from supraventricular arrhythmias. We sought to evaluate whether the response to antitachycardia pacing (ATP) in patients with an implantable cardioverter defibrillator could further discriminate ventricular from supraventricular arrhythmias in patients receiving ATP.

METHODS AND RESULTS

All episodes of ventricular or supraventricular tachycardia where ATP was delivered in patients enrolled in RAFT (Cardiac-Resynchronization Therapy for Mild-to-Moderate Heart Failure Trial) were included. RAFT randomized 1798 patients with New York Heart Association class II/III heart failure, left ventricular ejection fraction ≤30%, and QRS duration of ≥120 ms to a implantable cardioverter defibrillator±cardiac resynchronization therapy. The tachycardia cycle lengths (TCLs) before and after the delivery of ATP and the postpacing intervals were assessed. Overall, 10 916 ATP attempts were reviewed for 8150 tachycardia episodes in 924 patients. After excluding tachycardias where ATP terminated the episode or where the specific mechanism of the tachycardia was uncertain, we analyzed 3676 ATP attempts delivered for 2046 tachycardia episodes in 541 patients. A shorter difference between postpacing interval and TCL (PPI-TCL) was more likely to be associated with ventricular tachycardia than with supraventricular tachyarrhythmia (138.1±104.2 versus 277.4±126.9 ms; p<0.001). Analysis of the receiver operator curve for the PPI-TCL revealed an area under the curve of 0.803 (p<0.001; 95% confidence interval, 0.784-0.822). The majority of tachycardias with a PPI-TCL >360 ms were supraventricular with a PPI-TCL value of ≤360 ms having a sensitivity of 97.4% and specificity of 28.3% for ventricular tachycardia.

CONCLUSIONS

The ATP response, specifically the PPI-TCL, can further discriminate ventricular from supraventricular arrhythmias in patients with implantable cardioverter defibrillators when the currently available discriminators fail.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT00251251.

Inter- and Intraobserver Agreement of 18F-FDG PET/CT Image Interpretation in Patients Referred for Assessment of Cardiac Sarcoidosis

Recent studies have reported the usefulness of ¹⁸F-FDG PET in aiding with the diagnosis and management of patients with cardiac sarcoidosis (CS). However, image interpretation of ¹⁸F-FDG PET for CS is sometimes challenging. We sought to investigate the inter- and intraobserver agreement and explore factors that led to important discrepancies between readers. Methods: We studied consecutive patients with no significant coronary artery disease who were referred for assessment of CS. Two experienced readers masked to clinical information, imaging reports, independently reviewed ¹⁸F-FDG PET/CT images. ¹⁸F-FDG PET/CT images were interpreted according to a predefined standard operating procedure, with cardiac ¹⁸F-FDG uptake patterns categorized into 5 patterns: none, focal, focal on diffuse, diffuse, and isolated lateral wall or basal uptake. Overall image assessment was classified as either consistent with active CS or not. Results: One hundred scans were included from 71 patients. Of these, 46 underwent ¹⁸F-FDG PET/CT with a no-restriction diet (no-restriction group), and 54 underwent ¹⁸F-FDG PET/CT with a low-carbohydrate, high-fat and protein-permitted diet (low-carb group). There was agreement of the interpretation category in 74 of 100 scans. The κ-value of agreement among all 5 categories was 0.64, indicating moderate agreement. For overall clinical interpretation, there was agreement in 93 of 100 scans (κ = 0.85). When scans were divided into the preparation groups, there was a trend toward higher agreement in the low-carb group versus the no-restriction group (80% vs. 67%, P = 0.08). Regarding the overall clinical interpretation, there was also a trend toward greater agreement in the low-carb group versus the no-restriction group (96% vs. 89%, P = 0.08). Conclusion: The interobserver agreement of cardiac ¹⁸F-FDG uptake image patterns was moderate. However, agreement was better regarding overall interpretation of CS. Detailed prescan dietary preparation seemed to improve interobserver agreement.

Canadian Cardiovascular Society/Canadian Heart Rhythm Society 2016 Implantable Cardioverter-Defibrillator Guidelines

Sudden cardiac death is a major public health issue in Canada. However, despite the overwhelming evidence to support the use of implantable cardioverter defibrillators (ICDs) in the prevention of cardiac death there remains significant variability in implantation rates across Canada. Since the most recent Canadian Cardiovascular Society position statement on ICD use in Canada in 2005, there has been a plethora of new scientific information to assist physicians in their discussions with patients considered for ICD implantation to prevent sudden cardiac death due to ventricular arrhythmias. We have reviewed, critically appraised, and synthesized the pertinent evidence to develop recommendations regarding: (1) ICD implantation in the primary and secondary prevention of sudden cardiac death in patients with and without ischemic heart disease; (2) when it is reasonable to withhold ICD implantation on the basis of comorbidities; (3) ICD implantation in patients listed for heart transplantation; (4) implantation of a single- vs dual-chamber ICD; (5) implantation of single- vs dual-coil ICD leads; (6) the role of subcutaneous ICDs; and (7) ICD implantation infection prevention strategies. We expect that this document, in combination with the companion article that addresses the implementation of these guidelines, will assist all medical professionals with the care of patients who have had or at risk of sudden cardiac death.

Canadian Registry of Implantable Electronic Device Outcomes

Background—

The Riata lead under advisory has posed a unique clinical scenario where inside-out abrasion results in externalization of conductor cables, with a higher risk of electrical failure. We developed a comprehensive registry to assist with clinical management of this lead.

Methods and Results—

This Canadian registry reports the findings of 3763 (74.2% of all Riata leads in Canada) Riata leads under advisory, with a mean follow-up time of 8.9±1.5 years. The overall electrical failure rate was 5.2% at 8 years, with no difference between 7-French and 8-French lead models. Cable externalization was found to be more common in the 8-French model (12.3% versus 5.2%, P <0.0001) and was associated with a higher risk of electrical failure. Predictors of electrical lead failure included cable externalization, higher left ventricular ejection fraction, younger age, higher body mass index, and a passive fixation lead. One patient died due to electrical failure, a further 2 patients survived an event where the device failed to deliver high-voltage therapy. Major complications because of lead extraction were higher when compared with lead abandonment, no difference among lead model observed. Two deaths occurred as a consequence of lead extraction, in the context of an underlying infection.

Conclusions—

The Riata lead under advisory has a steady electrical failure rate over time. There are identifiable predictors of lead failure that can assist with clinical decisions as to whether lead revision should be performed prophylactically.

Strategy of continued vs interrupted novel oral anticoagulant at time of device surgery in patients with moderate to high risk of arterial thromboembolic events: The BRUISE CONTROL-2 trial

BACKGROUND

Patients who require perioperative anticoagulation during cardiac implantable electronic device surgery are at increased risk for bleeding complications. The BRUISE CONTROL trial demonstrated that continuing warfarin was safer than heparin bridging, reducing the incidence of clinically significant pocket hematoma. Novel oral anticoagulants are being increasingly prescribed in place of warfarin. The best perioperative management of these new anticoagulants is unknown.

METHODS/DESIGN

A randomized controlled trial to investigate whether a strategy of continued vs interrupted novel oral anticoagulant (dabigatran, rivaroxaban, or apixaban) at the time of device surgery, in patients with moderate to high risk of arterial thromboembolic events, reduces the incidence of clinically significant hematoma (defined as a hematoma requiring reoperation and/or resulting in prolongation of hospitalization, and/or requiring interruption of anticoagulation). The secondary outcomes include components of the primary outcome, composite of all other major perioperative bleeding events, thromboembolic events, all-cause mortality, cost-effectiveness, patient quality of life, perioperative pain, and satisfaction. Planned analyses include descriptive statistics of all baseline variables. For the primary outcome, interrupted vs continued novel oral anticoagulant arms will be compared using the χ(2) test. If any clinically significant differences are identified, a logistic regression analysis will be conducted. Quality of life will be assessed using EuroQol-5D, and perioperative pain using a visual analog scale.

DISCUSSION

BRUISE CONTROL-2 is a randomized trial evaluating the best strategy to manage novel oral anticoagulants at the time of device surgery. We hypothesize that device surgery can be performed safely without interruption of these medications.

Cardiac Sarcoidosis

Studies suggest clinically manifest cardiac involvement occurs in 5% of patients with pulmonary/systemic sarcoidosis. The principal manifestations of cardiac sarcoidosis (CS) are conduction abnormalities, ventricular arrhythmias, and heart failure. Data indicate that an 20% to 25% of patients with pulmonary/systemic sarcoidosis have asymptomatic (clinically silent) cardiac involvement. An international guideline for the diagnosis and management of CS recommends that patients be screened for cardiac involvement. Most studies suggest a benign prognosis for patients with clinically silent CS. Immunosuppression therapy is advocated for clinically manifest CS. Device therapy, with implantable cardioverter defibrillators, is recommended for some patients.

Myocardial injury secondary to ICD shocks: insights from patients with lead fracture

BACKGROUND

Patients who receive appropriate implantable cardioverter defibrillator (ICD) shocks have a subsequent adverse prognosis. Most data suggest that patients with inappropriate ICD shocks also have a subsequent adverse prognosis, although this is more controversial. The shocks may be an epiphenomenon, that is, a marker of underlying disease progression; however, it cannot be excluded that shocks cause direct myocardial damage. This latter question is difficult to clarify as the arrhythmia provoking the shock can also cause troponin release. Inappropriate shocks secondary to lead fracture are an ideal situation to examine this question; any troponin release in an otherwise well and hemodynamically stable patient, is likely due directly to the shocks.

METHODS

All patients with Fidelis lead fracture admitted to our institution with inappropriate shocks were included in this study. Troponin (I or T) was considered positive if the level was above the 99th percentile reference cutoff.

RESULTS

Elevated troponin levels were recorded in 16 of 22 patients (73%). Patients with elevated troponin received a higher number of shocks (20.3 ± 30.1 vs 5.3 ± 4.8, P = 0.07) compared with patients with normal troponin. Very elevated troponin levels (>0.8 mcg/L) were seen in five of 22 (22%) patients. The mean peak troponin level for these five patients was 7.06 ± 8.56 mcg/L; two patients had troponin levels that would be expected from a medium-sized myocardial infarction or severe myocarditis.

CONCLUSION

Troponin elevation occurred in the majority of our patients after inappropriate ICD discharges secondary to lead fracture. This indicates that ICD shocks can cause myocardial injury.

The use of 18F-FDG PET in the diagnosis of cardiac sarcoidosis: a systematic review and metaanalysis including the Ontario experience

Cardiac sarcoidosis is a potentially fatal complication of sarcoidosis. The 1993 guidelines of the Ministry of Health, Labour, and Welfare (MHLW) of Japan have been used as the diagnostic gold standard and for comparison with imaging modalities. (18)F-FDG PET is not currently included in the guidelines. However, studies have shown promising data using (18)F-FDG PET. We conducted a systematic review of studies that evaluated the accuracy of (18)F-FDG PET for the diagnosis of cardiac sarcoidosis compared with MHLW guidelines. Data from a prospective Ontario provincial registry are also reported and included in the metaanalysis.

METHODS

PubMed, Embase, and the Cochrane Central Register of Controlled Trials were searched for studies that satisfied predetermined criteria. Quality evaluation using the Quality Assessment for Diagnostic Accuracy Studies was performed by 2 independent masked observers. Data were extracted and analyzed to measure study-specific and pooled accuracy for (18)F-FDG PET compared with the MHLW as the reference.

RESULTS

A total of 519 titles was identified; 7 studies, including the Ontario registry, were selected for inclusion. Metaanalysis of these 7 studies was conducted, with a total of 164 patients, most of whom had been diagnosed with systemic sarcoidosis. The prevalence of cardiac sarcoidosis was 50% in the whole population. Pooled estimates for (18)F-FDG PET yielded 89% sensitivity (95% confidence interval [CI], 79%-96%), 78% specificity (95% CI, 68%-86%), a 4.1 positive likelihood ratio (95% CI, 1.7-10), and a 0.19 negative likelihood ratio (95% CI, 0.1-0.4). The overall diagnostic odds ratio was 25.6 (95% CI, 7.3-89.5), and the area under the summary receiver operator characteristic curve was 93% ± 3.5. The Ontario study yielded sensitivity and specificity of 79% and 70%, respectively.

CONCLUSION

The high diagnostic accuracy determined for (18)F-FDG PET in this metaanalysis suggests potential value for diagnosis of cardiac sarcoidosis compared with the MHLW guidelines. These results may affect patient care by providing supportive evidence for more effective use of (18)F-FDG PET in the diagnosis of cardiac sarcoidosis. Large-scale multicenter studies are required to further evaluate this role.

Prevalence and risk factors for cervical and lumbar spondylosis in interventional electrophysiologists

 

INTRODUCTION

The volume and complexity of interventional electrophysiology procedures have increased greatly over the last 20 years. Anecdotal reports from Canada and elsewhere have suggested an important prevalence of neck and back problems in interventional electrophysiologists.

METHODS AND RESULTS

To quantify the scope of neck and back problems, we surveyed 70 interventional electrophysiologists in Canada using an electronic survey with in person and email reminders. We also surveyed an age- and gender-matched group of noninterventional cardiologists. We received responses from a total of 58 of 70 interventional electrophysiologists (response rate 82.8%). There was a significantly higher prevalence of cervical spondylosis among electrophysiologists compared to matched noninterventional cardiologists (20.7% compared to 5.5%, P = 0.033). There was a trend for increased prevalence of lumbar spondylosis (25.9% compared to 16.7%, P = 0.298). Among electrophysiologists, those with cervical spondylosis were older (49.83 ± 10.48 years compared to 44.57 ± 9.20, P = 0.092) and had worked in the specialty for longer in comparison to unaffected physicians (19.67 ± 10.06 years compared to 13.37 ± 8.97 years, P = 0.039). All other variables including gender, height, weight, BMI, type of lead, weekly average lead time, and % of time standing in electrophysiology laboratory were not different. On multivariable analysis there were no independent predictors of disease.

CONCLUSIONS

There is a significant increased prevalence of cervical spondylosis among interventional electrophysiologists. Programs to improve ergonomics and minimize time spent wearing lead are needed. The same vigilance that is used to ensure radiation safety in the laboratory should be applied to create ergonomic safety.