Utility of the Modified Frailty Index to Predict Cardiac Resynchronization Therapy Outcomes and Response.

The aim of the present study was to investigate the utility of the modified frailty index (mFI) to predict outcomes in patients who underwent cardiac resynchronization therapy (CRT) device implantation. A retrospective cohort study of patients undergoing CRT implantation or upgrade over a 5-year period was performed. The relation between the preprocedural 11-component mFI and clinical outcomes including 1-year mortality, periprocedural and 30-day adverse events, 30-day readmission, length of hospitalization after procedure, and response to CRT defined by changes in left ventricular ejection fraction and end-diastolic volume were studied. Of 283 patients studied, 134 (47.3%) were classified as frail (mFI ≥3). Frailty was associated with an increased risk of 1-year mortality (hazard ratio 5.87, p = 0.033 in multivariate analysis), and increased frequency of adverse events (p = 0.013), 30-day readmission (p = 0.0077), and postprocedural length of stay ≥3 days (p = 0.0005). Frail patients had significantly less echocardiographic response to CRT compared with nonfrail patients with change in left ventricular ejection fraction 6% versus 12% (p = 0.004) and change in left ventricular end-diastolic volume -19.9 versus -43.3 ml (p = 0.006). In conclusion, frailty as assessed by the mFI is associated with an increase in 1-year mortality, adverse events, 30-day readmission, length of stay, and poorer response to CRT after implantation.

Risk of thromboembolic events after percutaneous left atrial appendage ligation in patients with atrial fibrillation: Long-term results of a multicenter study.

BACKGROUND: Percutaneous left atrial appendage (LAA) occlusion with Lariat has emerged as a viable alternative to oral anticoagulation (OAC) to prevent thromboembolic (TE) events in patients with atrial fibrillation. OBJECTIVE: We evaluated the long-term TE risk in post-Lariat patients. METHODS: Consecutive patients undergoing LAA ligation with the Lariat device at multiple centers with at least 1-year follow-up were included in the analysis. Transesophageal echocardiography (TEE) was performed at 4 weeks, 6 months, and 12 months to assess the completeness of LAA occlusion. OAC was discontinued if 4-week TEE revealed no device-related thrombus and complete closure of the appendage. Patients remained on 81 mg of aspirin per day after discontinuation of the blood thinner. RESULTS: A total of 306 patients were included in the study (mean age 68.8 ± 11.0 years; mean CHA2DS2-VASc score 3.6 ± 1.7). Four-week TEE revealed leaks in 81 patients (26.5%); all leaks were less than 5 mm in diameter. At 6-month TEE, spontaneous closure of the leak was demonstrated in 21 patients (25.9%), 26 patients (32%) underwent a successful leak closure procedure, and the remaining 34 (42%) patients were placed on OAC. At the median follow-up period of 15.9 ± 9.2 months, 9 TE events (2.9%) were reported: 7 with persistent leak and 2 without any detectable leaks on 2-dimensional TEE (P < .001). CONCLUSION: Complete occlusion of the LAA with the Lariat device was associated with the low rate of TE events at long-term follow-up. However, residual leaks were common after Lariat closure and the stroke rate was significantly higher in patients with incomplete occlusion, even with small leaks.

Use of antimicrobial agent pocket irrigation for cardiovascular implantable electronic device infection prophylaxis: Results from an international survey.

PURPOSE: Survey the usage and application protocol of antimicrobial agent pocket irrigation for cardiovascular implantable electronic device (CIED) infection prophylaxis. BACKGROUND: Local antibiotic usage for CIED infection prophylaxis, in particular pocket irrigation, is a well-known strategy but with little data on its clinical effectiveness. METHODS: An anonymous voluntary online survey was sent to a total of 2,092 arrhythmia-oriented cardiologists in 51 countries (1,490 from the United States). RESULTS: There were 487 responses (response rate 23.3%: U.S. 28.2%, outside of the U.S. 11.1%). Eighty-seven percent of respondents use intraoperative antimicrobial agent pocket irrigation and/or an antimicrobial eluting pouch to reduce CIED infection. Fifty-four percent of respondents believe that it is effective to use an antimicrobial agent pocket irrigation to reduce CIED infection; 33% of respondents are uncertain; a few consider this strategy ineffective (13%) or offered no opinion. Significant differences exist in the practice patterns and beliefs between the U.S. and non-U.S. countries (P < 0.05). Ninety-eight percent of respondents report using the same pocket irrigation protocol for permanent pacemaker versus implantable cardioverter defibrillator. Bacitracin (48%), vancomycin (39%), and a cephalosporin (29%) are the most commonly chosen antibiotics. A majority of the respondents are unaware of the cost of using antimicrobial agent pocket irrigation (69%) and neither are they concerned (67%). CONCLUSION: This international survey suggests that, while there are little clinical data to support or discourage such practice, the usage of antimicrobial agent pocket irrigation for CIED infection prophylaxis is widely used in current practice.

Clinical Implications of Leaks Following Left Atrial Appendage Ligation With the LARIAT Device.

OBJECTIVES: The aim of this study was to evaluate the incidence and clinical implications of leaks (acute incomplete occlusion, early and late reopenings) following LAA ligation with the LARIAT device. BACKGROUND: Percutaneous LAA ligation with the LARIAT device may represent an alternative for stroke prevention in high-risk patients with atrial fibrillation with contraindications to oral anticoagulation. METHODS: This was a retrospective, multicenter study of 98 consecutive patients undergoing successful LAA ligation with the LARIAT device. Leaks were defined as the presence of flow as evaluated by transesophageal echocardiography (TEE). TEE was performed during the procedure, at 6 and 12 months, and after thromboembolic events. RESULTS: Leaks were detected in 5 (5%), 14 (15%), and 19 (20%) patients at the 3 time points. During follow-up, 5 patients developed neurological events (4 strokes and 1 transient ischemic attack). Two occurred early (1 fatal stroke and 1 stroke with multiple recurrences in the following months), and TEE was not repeated after the events. The remaining 3 occurred late (after 6 months) and were associated with small leaks (<5 mm). In 2 of 3 cases, such a small leak was missed by the standard evaluation on 2-dimensional TEE, being evident only with the aid of 3-dimensional imaging. CONCLUSIONS: Incomplete occlusion of the LAA after LARIAT ligation is relatively common and may be associated with thromboembolic events. Proper long-term surveillance with careful TEE should be considered to detect leaks, which can be managed with either resumption of oral anticoagulation or percutaneous transcatheter closure.

Referral Patterns for Primary Prophylaxis Implantable Cardioverter Defibrillator Therapy for an Urban US Population.

Implantable cardioverter defibrillators (ICDs) have been demonstrated to improve survival for both primary and secondary prevention of sudden cardiac arrest. However, studies suggest that ICD therapy is underused in appropriate candidates. Sex and racial disparities in ICD use have been suggested. We sought to characterize the referral patterns of high-risk patients for the primary prophylaxis of sudden cardiac arrest at a tertiary academic medical center serving a diverse population in an urban US setting. Electronic hospital databases were retrospective reviewed for patients meeting criteria for prophylactic ICD implantation. We evaluated the association of gender, age, race, and primary language with the referral and subsequent implantation of an ICD. We identified 1,055 patients satisfying prophylactic ICD criteria: 600 men, mean age 62.6 years, 27.6% black, 19.3% white, 23.3% Hispanic, and 49.8% primary language of English. Of the 673 patients (63.7%) referred for ICD evaluation, 345 underwent implantation, 125 declined, and 203 had significant co-morbidities that precluded implantation. Gender, race, and primary language were not associated with referral for ICD or with decision to proceed with implantation. Patients of increased age were less likely to be referred for ICD and were more likely to refuse implantation. ICD therapy was not considered in 146 patients eligible for prophylactic implantation. In conclusion, referral rates for ICD consideration were higher at our institution than in previous reports. Nonetheless, 14% of appropriate patients were not considered. This argues for the importance of increased education for patients and referring physicians.

Prognostic value of automatically detected early repolarization.

Early repolarization associated with sudden cardiac death is based on the presence of >1-mm J-point elevations in inferior and/or lateral leads with horizontal and/or downsloping ST segments. Automated electrocardiographic readings of early repolarization (AER) obtained in clinical practice, in contrast, are defined by ST-segment elevation in addition to J-point elevation. Nonetheless, such automated readings may cause alarm. We therefore assessed the prevalence and prognostic significance of AER in 211,920 patients aged 18 to 75 years. The study was performed at a tertiary medical center serving a racially diverse urban population with a large proportion of Hispanics (43%). The first recorded electrocardiogram of each individual from 2000 to 2012 was included. Patients with ventricular paced rhythm or acute coronary syndrome at the time of acquisition were excluded from the analysis. All automated electrocardiographic interpretations were reviewed for accuracy by a board-certified cardiologist. The primary end point was death during a median follow-up of 8.0 ± 2.6 years. AER was present in 3,450 subjects (1.6%). The prevalence varied significantly with race (African-Americans 2.2%, Hispanics 1.5%, and non-Hispanic whites 0.9%, p <0.01) and gender (male 2.4% vs female 0.6%, p <0.001). In a Cox proportional hazards model controlling for age, smoking status, heart rate, QTc, systolic blood pressure, low-density lipoprotein cholesterol, body mass index, and coronary artery disease, there was no significant difference in mortality regardless of race or gender (relative risk 0.98, 95% confidence interval 0.89 to 1.07). This was true even if J waves were present. In conclusion, AER was not associated with an increased risk of death, regardless of race or gender, and should not trigger additional diagnostic testing.

Rate of cardiovascular implantable electronic device (CIED) re-extraction after recurrent infection.

BACKGROUND: Patients who develop a cardiovascular implantable electronic device (CIED) infection requiring extraction may have risk factors that make them prone to developing another infection of the reimplanted CIED. However, the rate of a second infection requiring repeat extraction in such patients is unknown and may have important clinical implications. METHODS: We retrospectively reviewed all patients at our institution from January 2001 to October 2012 who underwent a CIED extraction for an infection and then required reimplantation. We then reviewed the incidence of a repeat extraction due to a second infection. Clinical and device parameters at the time of the second infection were retrieved. RESULTS: There were 168 patients who underwent a CIED extraction because of infection and were subsequently reimplanted. The median time to reimplantation was 3 [1(st) quartile: 1, 3(rd) quartile: 10] days. After a mean follow-up of 4.4 ± 2.7 years, nine (5.4%) patients underwent a repeat CIED extraction due to a second infection. Six repeat extractions (67%) occurred in the first year, leading to an event rate of 3.9% within 1 year of reimplantation. Patients with a second infection requiring a repeat CIED extraction were younger (57 ± 20 vs 68 ± 16, P = 0.046). Pocket infection was the most common presentation of a second infection, occurring in eight of the nine patients. CONCLUSION: The rate of a second infection leading to a CIED repeat extraction is elevated within the first year after reimplantation. To determine predictors of recurring infection, analysis of a larger multicenter series is warranted.

Impact of metabolic syndrome on the risk of atrial fibrillation recurrence after catheter ablation: systematic review and meta-analysis.

PURPOSE: The impact of metabolic syndrome (MetS) on recurrence of atrial fibrillation (AF) after catheter ablation remains uncertain. We conducted a meta-analysis to summarize the relative risks (RR) of AF recurrence after catheter ablation in patients with vs. without MetS and its components. METHODS: Among 839 articles identified from PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials, we included 23 studies with a total of 12,924 patients (7,594 with paroxysmal AF and 5,330 with nonparoxysmal AF) for analysis. Five of these had complete information on MetS components. Variables assessed comprised study design and population characteristics, AF ablation methods, use of anti-arrhythmic drugs, AF recurrence ascertainment methods, adjustment variables, and other quality indicators. RESULTS: Our meta-analysis found an elevated risk of AF recurrence after ablation in patients with vs. without MetS (pooled RR, 1.63; 95 % confidence interval (CI), 1.25-2.12). Among components of MetS, hypertension was a predictor of AF post-ablation recurrence in studies without adjustment for other MetS components (RR, 1.62; 95 % CI, 1.23-2.13) but not in those adjusting for two or more additional MetS components (RR, 1.03; 95 % CI, 0.88-1.20). There was a borderline association between overweight/obesity and AF recurrence after ablation (RR, 1.27; 95 % CI, 0.99-1.64). CONCLUSIONS: MetS is associated with an increased risk of AF recurrence after catheter ablation. Further study of the MetS and its components as determinants of AF risk could help refine patient selection and improve procedural outcomes.

Subclavian venoplasty may reduce implant times and implant failures in the era of increasing device upgrades.

BACKGROUND: The incidence of subclavian venous occlusions (SCVOs) may be an increasing problem in the era of device upgrades, especially to cardiac resynchronization therapy. Venoplasty (VP) performed by the electrophysiologist as a way of managing SCVOs may be advantageous. METHODS: We reviewed the implantable cardioverter defibrillator (ICD) implants of the past 5 years at Montefiore Medical Center and searched for SCVOs that required intervention and compared cases where VP was performed with cases where it was not. RESULTS: Of 1,853 ICD implants, 41 SCVOs (2.2%) requiring intervention were identified. Its incidence increased seven-fold from 0.7% in 2005 to 5.2% in 2009. Twenty-seven of the 41 SCVOs were found during a device upgrade. Of these 41 SCVOs, 18 underwent VP and 23 did not. In the VP group, there was a trend towards a shorter total procedure time, 2:31 hours versus 3:28 hours (P=0.37), and the total fluoroscopy time was 30 minutes versus 27 minutes (P=0.55). VP was successful in all 18 patients. Among the non-VP group (n=23), five (21.5%) had a failed implantation because of the inability to gain venous access and 10 (42.7%) had to be implanted on the contralateral side. CONCLUSION: The incidence of SCVOs requiring intervention is increasing in the era of device upgrades. VP performed by an electrophysiologist appears to be a safe and efficient approach to manage these SCVOs. VP seems to reduce the implant time and the need to implant on the other side as well as implant failure due to the inability to gain venous access.

Ablation of peri-"mitral" flutter in a patient with congenitally corrected transposition of great vessels and situs inversus.

This case reports the successful ablation of a peri-"mitral" flutter in a patient with congenitally corrected transposition of the great vessels and situs inversus using an anterior mitral line.

Transvenous dual site left ventricular pacing to lower elevated pacing thresholds.

Dual site left ventricular pacing through two left ventricular pacing leads, located in discrete vessels, significantly lowered pacing thresholds from 6 V at 1 ms and 4.25 V at 0.5 ms through the leads individually, to 0.75 V at 0.5 ms by utilizing a Y-adaptor to connect the two leads.

2:1 left to right interatrial block and other effects of ibutilide during non-isthmus-dependent atrial flutter.

The effects of ibutilide on non-isthmus-dependent atrial flutter (NIDAFL) and the left atrium are not completely known. We describe a case report of 2:1 left to right interatrial block as a result of ibutilide during NIDAFL. This is a 68-year-old man with history of right atrial flutter ablation who presented with recurrence of atrial flutter and underwent a diagnostic electrophysiology study. A 20-pole catheter with 2-10-mm spacing was used spanning the cavotricuspid isthmus to the midcoronary sinus. Morphology of the flutter waves and atrial activation sequence was recorded. Ibutilide was given to terminate the atrial flutter. During administration, 2:1 left-to-right interatrial block was seen. In addition, the cycle length of the flutter prolonged, yet the activation sequence did not change. Ibutilide terminated the flutter. During sinus rhythm, interatrial block was not seen. This case report illustrates an example of 2:1 left to right interatrial conduction block because of ibutilide during a non-isthmus-dependent atrial flutter.

Venoplasty of innominate bridge during implantation of single-chamber ICD in a patient with a persistent left-sided superior vena cava.

The persistent left-sided superior vena cava (PLSVC) is a common congenital abnormality, occurring in approximately 1% of patients. The presence of a PLSVC can complicate the implantation of a pacemaker or an automatic implantable cardioverter-defibrillator (AICD). In this case, we report a procedure, venoplasty of an innominate branch, to facilitate implantation of a right ventricular lead in a single-chamber AICD. This approach could potentially reduce procedure and fluoroscopy time in other similar cases.

Intravenous sedation for cardiac procedures can be administered safely and cost-effectively by non-anesthesia personnel.

AIMS: Primary: to determine the safety and efficacy of intravenous sedation for cardiac procedures administered by non-anesthesia personnel. Secondary: to assess cost effectiveness of such sedation. METHODS: Anesthesiologists trained non-anesthesia personnel, and established our sedation protocol, which was then used in 9,558 patients who had cardiac procedures with sedation by non-anesthesia personnel, recorded on a computerized database. Most sedation used was midazolam (MID) and morphine (MOR). Complications and problems were derived from the database and quality assurance committee records. Doses were based on desired level of sedation and procedure duration; highest dose used: MID 78 mg, MOR 84 mg. RESULTS: Data included catheterization (n = 3,819) and transesophageal echo procedures (n = 260); and overall electrophysiology (n = 5,479) and selected subsets. There were complications or problems in only 9 patients (0.1%), a strong safety statement. There were 3 deaths in electrophysiology related procedures, 2 deaths in catheterization related procedures, all in very sick patients and not definitely related to sedation; 4 others developed clinical instability (hives, hypotension and heart failure-all with no sequellae), 2 of which needed reversal medications. Three patients (<0.03%) proved difficult to sedate, and their procedures were completed with help from the anesthesia department; by protocol this was not a complication. A total of $5,365,691 was saved during the last decade on cardiac procedures performed with conscious sedation. CONCLUSION: Non-anesthesia personnel can administer intravenous sedation for cardiac procedures in cardiac settings, with safety and cost-effectiveness demonstrated over many years. Anesthesia services are still appropriate for selected cases.

DP+1: another simple endpoint for atrial flutter ablation.

BACKGROUND: When double potentials (DP) on the line of block are difficult to see, we propose another simple method to verify complete bidirectional block (CBDB) at the end of an atrial flutter ablation. We measured the interval between the electrograms immediately on either side of the line of block on a multipole catheter spanning the isthmus. We called this interval "DP+1" because it is one pair of electrodes away from the DP on the line of block. METHODS: Fifty consecutive patients (age 62 +/- 13 years, LVEF 54 +/- 11%, mean cycle length 241 +/- 34 ms) underwent an atrial flutter ablation using a duodecapolar catheter with 2-10 mm spacing with the distal tip inserted into the mid-coronary sinus and the rest of the poles spanning the isthmus and the low lateral right atrium. Radiofrequency ablation was performed using a 10-mm tip electrode (EP Technologies). The ablation endpoint was the creation of a craniocaudal activation pattern of the opposite wall to the pacing site (septal and lateral of the line of block). RESULTS: The ablation endpoint was achieved in 48 of 50 (96%) patients with 8 +/- 2 RF applications. Adequate DP were found in only 22 of 50 patients (44%), but the DP+1 interval was measurable in all patients. When no block was present, the DP+1 interval was 81 +/- 10 ms, and 160 +/- 18 ms when complete bidirectional block was present (P < 0.001). A DP+1 interval of >140 ms had 100% specificity, 96% sensitivity, 100% positive predictive value for verifying complete bidirectional block. After a follow-up of 528 +/- 253 days, there were no recurrences of AFL, but there were four recurrences of AF (8%). CONCLUSION: When DP cannot be seen, another simple method for verifying CBDB in ablation of typical atrial flutter is a DP+1 interval > 140 ms.

Effects of cardioactive medications on retrograde conduction: continuing relevance for current devices.

INTRODUCTION: Retroconduction (ventriculo-atrial conduction) remains a problem for patients with implanted cardiac rhythm devices. Pacemaker algorithms can detect and terminate endless loop tachycardia (ELT), but actual prevention of ELT may require anti-arrhythmic drugs (AADs). Similarly, AADs can affect ICD rhythm discrimination algorithms that depend on atrio-ventricular ratios. There is concern whether these drugs remain effective during stress situations. METHODS: Electrophysiologic studies that included retroconduction testing using slow ramp pacing were done in 1332 patients. The presence or absence of retroconduction at baseline and with drug was recorded, as was the rate at block. As a stress surrogate, isoproterenol was used to test retroconduction and reversal of drug-induced block. RESULTS: Procainamide, mexiletine, phenytoin, disopyramide, quinidine, beta-blockers, encainide, and amiodarone caused complete retrograde block or decreased the rate at which block occurred (mean 76% of patients, p < 0.008), whereas digoxin, lidocaine, diltiazem, and verapamil did not. Isoproterenol (in the absence of AADs) increased the rate at block in 82% of 404 patients with retroconduction at baseline (p < 0.005). Of 319 patients without retroconduction at baseline, 134 (42%) developed retroconduction after isoproterenol. Isoproterenol reversed retrograde block in 39% of patients with block on an AAD. Amiodarone, digoxin, and the combination of digoxin plus a beta-blocker were most effective at resisting this reversal of ventriculo-atrial block (80%, 68%, and 75% respectively). CONCLUSION: Most of the AADs reviewed increase the cycle length at block or abolish retroconduction, while isoproterenol has the opposite effect. Anti-arrhythmic medications, particularly amiodarone, digoxin, and the combination of digoxin plus a beta-blocker may be considered for a patient with multiple ELT episodes or certain ICD detection problems.

Atrial fibrillation ablation: reaching the mainstream.

INTRODUCTION AND AIMS: Ablation of atrial fibrillation (AF) has evolved rapidly in the decade since its inception. We aimed to review the results of this evolution as reflected in the published literature. METHODS: Publications through 2005 were reviewed, and data included if there was information on the technique used, and follow-up of at least 6 months. RESULTS: More than 23,000 patients met criteria for inclusion. There has been a steady improvement in reported outcomes (P<0.001). Variations on radiofrequency catheter ablation for pulmonary vein isolation result in apparent elimination ("cure") or improvement of AF in 75%, and surgical techniques are even better. CONCLUSIONS: Catheter ablation of AF is now a mainstream procedure. Continuing technical advances are needed to achieve better results with more uniformity and reduced procedure times.