Rohit Rattan

Fluoroscopic Screening of Asymptomatic Patients Implanted With the Recalled Riata Lead Family

Background— The Food and Drug Administration recently issued a class I recall of the St. Jude Medical Riata implantable cardioverter-defibrillator lead presumably because of increased risk of electric failure and mechanical separation via inside-out abrasion. We sought to examine the incidence and time dependence of inside-out abrasion in asymptomatic patients implanted with the Riata lead. Methods and Results— Asymptomatic patients implanted with the Riata lead at our institution were offered voluntary fluoroscopic screening in 3 views. Electric testing of the Riata lead with provocative isometric muscle contraction was performed at the time of fluoroscopic screening. Of the 245 patients undergoing fluoroscopic screening, 53 (21.6%) patients showed clear evidence of lead separation. Of these externalized leads, 0%, 13%, and 26% had a dwell time of <3 years, 3 to 5 years, and >5 years, respectively (P=0.037). Externalized leads had a significantly pronounced decrease in R-wave amplitude (−1.7±2.9 mV versus +0.35±2.5 mV; P<0.001), and more patients with externalized leads had ≥25% decrease in R-wave amplitude from baseline (28.0% versus 8.1%; P=0.018). One patient with externalization exhibited new noise on near-field electrogram. Conclusions— The Riata lead exhibits time-dependent high rates of cable externalization exceeding 20% at >5 years of dwell time. Externalized leads are associated with a more pronounced decrease in R-wave amplitude, which may be an early marker of future electric failure. The use of fluoroscopic and electric screening of asymptomatic patients with the Riata lead remains controversial in the management of patients affected by the recent Food and Drug Administration recall.

Battery longevity in cardiac resynchronization therapy implantable cardioverter defibrillators

AIMS Cardiac resynchronization therapy (CRT) implantable cardioverter defibrillators (ICDs) deliver high burden ventricular pacing to heart failure patients, which has a significant effect on battery longevity. The aim of this study was to investigate whether battery longevity is comparable for CRT-ICDs from different manufacturers in a contemporary cohort of patients. METHODS AND RESULTS All the CRT-ICDs implanted at our institution from 1 January 2008 to 31 December 2010 were included in this analysis. Baseline demographic and clinical data were collected on all patients using the electronic medical record. Detailed device information was collected on all patients from scanned device printouts obtained during routine follow-up. The primary endpoint was device replacement for battery reaching the elective replacement indicator (ERI). A total of 646 patients (age 69 ± 13 years), implanted with CRT-ICDs (Boston Scientific 173, Medtronic 416, and St Jude Medical 57) were included in this analysis. During 2.7 ± 1.5 years follow-up, 113 (17%) devices had reached ERI (Boston scientific 4%, Medtronic 25%, and St Jude Medical 7%, P < 0.001). The 4-year survival rate of device battery was significantly worse for Medtronic devices compared with devices from other manufacturers (94% for Boston scientific, 67% for Medtronic, and 92% for St Jude Medical, P < 0.001). The difference in battery longevity by manufacturer was independent of pacing burden, lead parameters, and burden of ICD therapy. CONCLUSION There are significant discrepancies in CRT-ICD battery longevity by manufacturer. These data have important implications on clinical practice and patient outcomes.

Failure-free survival of the Durata defibrillator lead

AIMS Given design similarities and a common manufacturer, there have been suspicions regarding the Durata™ defibrillator (ICD) lead, in the aftermath of the Riata™ class I recall. We therefore examined the failure-free survival rates of the Durata™ compared with the Riata™ and Sprint Quattro™ ICD leads. METHODS AND RESULTS All patients (n = 2475) implanted with a Durata (n = 828), Riata [n = 627; 8 Fr. (n = 472) and 7 Fr. (n = 155)], or Sprint Quattro (n = 1020) leads at our institution were included and Kaplan-Meier failure-free survival curves were constructed for all leads. Lead failure was defined as electrical malfunction resulting in lead replacement, excluding dislodgements or perforations. Annual electrical failure rates were 0.3%, 1.7, and 0.3% for the Durata, Riata, and Sprint Quattro leads, respectively (P < 0.0001 for the comparison of Durata to Riata and P = 0.1.0 for the comparison of Durata to Sprint Quattro). The failure-free survival of the Durata lead was significantly better than that of the Riata lead (P < 0.0001) and similar to that of the Sprint Quattro (P = 0.94). The 7 Fr. Riata ST lead had better survival compared with the 8 Fr. Riata lead (P = 0.050) and comparable survival with the Durata lead (P = 0.12). CONCLUSION The Durata lead failure-free survival is significantly better than the 8 Fr. Riata, albeit at a shorter follow-up time. Riata and comparable with that of the 7 Fr. Riata ST and the Sprint Quattro ICD leads. These data provide an insight into the mechanism of electrical failure of Riata leads and have implications for patient management.

Outcomes of Sprint Fidelis and Riata lead extraction: Data from 2 high-volume centers

BACKGROUND The Sprint Fidelis (SF) and the Riata (RT) implantable cardioverter-defibrillator leads have been recalled for premature failure. OBJECTIVE Data on SF and RT extractions are limited; therefore, we performed a pooled analysis to compare the safety and efficacy of lead extraction for the SF and RT lead families. METHODS We retrospectively reviewed consecutive patients undergoing transvenous extraction of SF and RT leads at Emory University and the University of Pittsburgh Medical Center from January 2007 to October 2013. Patients were placed into 2 groups based on the presence of an SF or RT lead. The primary endpoint was a major procedural complication, defined as death, need for urgent cardiac surgery, and hemopericardium or hemothorax that required an intervention. RESULTS A total of 462 patients underwent extraction of recalled leads (SF, n = 360; RT, n = 102). The mean number of leads extracted in the RT group was higher than in the SF group (1.8 ± 0.9 vs 1.3 ± 0.7, P < .001), and there was a longer implantation time in the RT group (5.5 ± 2.5 vs 4.3 ± 2.0 years, P < .001). Complete procedural success was higher in the SF group (99.4% vs 96.1%, P =.024). Clinical success was similar (SF 99.4% vs RT 97.1%, P = .075). There were 6 major procedural complications in the entire cohort (1.3%). The rate of major complications was not different between the SF and RT groups (SF 1.1% vs RT 2.0%, P = .618). Total mortality was 0.65%, with no difference between the groups CONCLUSION Our data from 2 high-volume centers suggest that extraction of SF and RT leads is associated with excellent clinical success and a similar rate of major procedural complications.

Comparative effectiveness of antiarrhythmic drugs for rhythm control of atrial fibrillation

INTRODUCTION Although there are many different antiarrhythmic drugs (AADs) approved for rhythm management of atrial fibrillation (AF), little comparative effectiveness data exist to guide drug selection. METHODS We followed 5952 consecutive AF patients who were prescribed amiodarone (N=2266), dronedarone (N=488), dofetilide (N=539), sotalol (N=1718), or class 1C agents (N=941) to the primary end point of AF recurrence. RESULTS Median follow-up time was 18.2 months (range 0.1-101.6 months). Patients who were prescribed amiodarone had the highest, while patients on class 1C agents had the lowest baseline CHA2DS2-VASc score, Charlson comorbidity index, and burden of comorbid illnesses including coronary artery disease, congestive heart failure, diabetes mellitus, hyperlipidemia, chronic obstructive lung disease, chronic kidney disease, or cancer (p<0.05 for all comparisons). After adjusting for baseline characteristics, using dronedarone as benchmark, amiodarone [hazard ratio (HR) 0.58, p<0.001], class 1C agents (HR 0.70, p<0.001), and sotalol (HR 0.79, p=0.008), but not dofetilide (HR 0.87, p=0.178) were associated with less AF recurrence. In addition, compared to dronedarone, amiodarone and class 1C agents were associated with lower rates of admissions for AF (HR 0.55, p<0.001 for amiodarone; HR 0.71, p=0.021 for class 1C agents) and all-cause mortality was lowest in patients treated with class 1C agents (HR 0.42, p=0.018). The risk of stroke was similar among all groups. CONCLUSION Compared with dronedarone, amiodarone, class 1C agents, and sotalol are more effective for rhythm control, while dofetilide had similar efficacy. These findings have important implications for clinical practice.

Risk of Stroke and Death in Atrial Fibrillation by Type of Anticoagulation: A Propensity‐Matched Analysis

We examined the effect of novel oral anticoagulants (NOACs) compared to warfarin on the risk of death or stroke in atrial fibrillation (AF) patients in every day clinical practice.

Patient Outcomes According to Adherence to Treatment Guidelines for Rhythm Control of Atrial Fibrillation

Background Although guidelines for antiarrhythmic drug therapy in atrial fibrillation (AF) were published in 2006, it remains uncertain whether adherence to these guidelines affects patient outcomes. Methods and Results We retrospectively evaluated the records of 5976 consecutive AF patients who were prescribed at least 1 antiarrhythmic drug between 2006 and 2013. Patients with 1 or more prescribed antiarrhythmic drugs that did not comply with guideline recommendations comprised the non–guideline‐directed group (=2920); the remainder constituted the guideline‐directed group (=3056). Time to events was assessed using the survival analysis method and adjusted for covariates using Cox regression. Rates of adherence to the guidelines increased significantly with a higher degree of prescriber specialization in arrhythmias (49%, 55%, and 60% for primary care physicians, general cardiologists, and cardiac electrophysiologists, respectively, P=0.001) for the first prescribed antiarrhythmic drug. Compared to the non–guideline‐directed group, the guideline‐directed group had higher rates of heart failure, but lower baseline CHADS2‐VASc scores (P<0.001) and lower rates of coronary artery disease, valvular disease, hypertension, hyperlipidemia, pulmonary disease, and renal insufficiency (P<0.05 for all). During 45±26 months follow‐up, the guideline‐directed group had a lower risk of AF recurrence (hazard ratio=0.86, 95% CI=0.80 to 0.93), fewer hospital admissions for AF (hazard ratio=0.87, 95% CI=0.79 to 0.97), and fewer procedures for recurrent AF, including electrical cardioversion, pacemaker implantation, and atrioventricular nodal ablation (P<0.01 for all). The mortality and stroke risks were similar between the groups. Conclusions Adherence to published guidelines in the antiarrhythmic management of AF is associated with improved patient outcomes.

Lead related complications in quadripolar versus bipolar left ventricular leads

Background Quadripolar left ventricular (LV) leads are capable of pacing from four different electrodes which allows for easier and more stable intra-operative lead positioning with optimal pacing parameters. We therefore investigated the rate of combined intra-operative and post-operative LV lead related events in quadripolar vs. bipolar LV lead cardiac resynchronization therapy (CRT) recipients in the real world setting. Methods We retrospectively collected data for N = 1441 patients at our institution implanted with quadripolar (n = 292) or bipolar (n = 1149) LV leads from 2012 to 2014 and followed them to the primary end-point of composite lead outcome defined as intra-operative lead implant failure or post-operative lead dislodgement or deactivations. Results Patients implanted with a quadripolar lead were younger (70.6 ± 11.4 vs 72.5 ± 11.6, p = 0.014) and had higher incidence of diabetes (41.8% vs 32.8%, p = 0.004) compared to those with bipolar leads. All other baseline characteristics were comparable. Patients implanted with a quadripolar were significantly less likely to reach the primary endpoint in the first 12 months after LV lead implantation (Hazard Ratio 0.22, 95% Confidence Interval 0.08–0.60, p = 0.001). There were no differences between the two groups in rates of hospitalization for any cause or in mortality. Conclusion In this real world study, quadripolar LV leads have significantly lower rates of implantation failure and post-operative lead dislodgement or deactivation. These results have important clinical implications to CRT recipients.

Mortality risk of long-term amiodarone therapy for atrial fibrillation patients without structural heart disease.

BACKGROUND Amiodarone is often prescribed in the management of atrial fibrillation (AF) but is known to cause significant end-organ toxicities. In this study, we examined the impact of amiodarone on all-cause mortality in AF patients with structurally normal hearts. METHODS We performed a retrospective cohort analysis of all AF patients with structurally normal hearts who were prescribed antiarrhythmic drugs (AAD) for rhythm control of AF at our institution from 2006 to 2013 (n = 2,077). Baseline differences between the amiodarone (AMIO: n = 403) and other AADs (NON-AMIO: n = 1,674) groups were corrected for using propensity score matching. RESULTS Amiodarone use as first-line therapy decreased significantly with a higher degree of prescriber specialization in arrhythmia management (31%, 22%, and 9% for primary care physicians, general cardiologists and cardiac electrophysiologists, respectively, p < 0.001). After propensity score matching, baseline comorbidities were balanced between the AMIO and NON-AMIO groups. Over a median follow-up of 28.2 months (range 6.0-100.9 months), amiodarone was associated with increased all-cause (HR 2.41, p = 0.012) and non-cardiac (HR 3.55, p = 0.008) mortality, but not cardiac mortality. AF recurrence and cardiac hospitalizations were similar between the two study groups. CONCLUSIONS Amiodarone treatment of AF is associated with increased mortality in patients without structural heart disease and therefore should be avoided or only used as a second-line therapy, when other AF therapies fail. Adherence to guideline recommendations in the management of AF patients impacts clinical outcome.

Sudden cardiac arrest in end-stage renal disease patients on dialysis: A nationwide study

Sudden cardiac arrest (SCA) is frequently encountered in end‐stage renal disease (ESRD) patients on dialysis. There is a dearth of national data on SCA‐associated outcomes in this specific patient population. The aim of the present study is to study these parameters from a nationally representative US population.