Catheter ablation of atrial fibrillation in elderly and very elderly patients: safety, outcomes, and quality of life

BACKGROUND

Atrial fibrillation (AF) risk increases with age. We aim to assess the efficacy and safety of catheter ablation in the older population.

METHODS

All patients undergoing AF ablation (2013-2021) at our institution were enrolled in a prospectively maintained registry. The primary endpoint was AF recurrence. Patients were divided into 3 groups: non-elderly (< 65 years), elderly (65-75 years), and very elderly (> 75 years). Patient surveys at baseline and during follow-up were used to calculate quality of life (QoL) metrics: the AF severity score as well as the AF burden.

RESULTS

A total of 7020 patients were included (42% non-elderly, 42% elderly, and 16% very elderly). Periprocedural major complications were low (< 1.5%) and similar in all groups besides pericardial effusion which was more frequent with older age and similar between the elderly and very elderly. At 3 years, AF recurrence for persistent AF (PersAF) was highest in the very elderly group (48%), followed by the elderly group (42%), and was the lowest in the non-elderly group (36%). In paroxysmal AF (PAF), there was no difference in AF recurrence between the elderly and non-elderly, while the very elderly remained associated with a significantly increased risk. Multivariable Cox analysis confirmed these findings (PersAF; elderly: HR = 1.23, P = 0.003; very elderly: HR = 1.44, P < 0.001) (PAF; elderly: HR = 1.04, P = 0.62; very elderly: HR = 1.30, P = 0.01). Catheter ablation resulted in a significant improvement in quality of life, irrespective of age group.

CONCLUSION

Catheter ablation in elderly and very elderly patients is safe, efficacious, and associated with QoL benefits. Overall, major complications were minimal and did not differ significantly between age groups, with the exception of pericardial effusions which were higher in the elderly and very elderly compared to non-elderly adults. Very elderly patients had a higher rate of AF recurrence when compared with elderly or non-elderly patients. Nevertheless, ablation resulted in a remarkable improvement in QoL and a reduction of AF burden and AF symptoms with a similar magnitude, irrespective of age.

Clinical Predictors of Incomplete CS Lead Removal during Transvenous Lead Extraction in the Patients with Cardiac Resynchronization Therapy

BACKGROUND

Reports of coronary sinus (CS) lead removal include small studies with short implant durations. Procedural outcomes for mature CS leads removed with long duration implantation are unavailable.

OBJECTIVE

To examine the safety, efficacy, and clinical predictors for incomplete CS lead removal by Transvenous Lead Extraction (TLE) in a large, long implant duration cardiac resynchronization therapy (CRT) patient cohort.

METHODS

Consecutive patients with CRT devices in the Cleveland Clinic Prospective TLE Registry who had TLE between 2013 and 2022.

RESULTS

CS leads, n=231, implant duration = 6.1±4.0 years, removed from 226 patients were included, employing powered sheaths for 137 leads (59.3%). Complete CS lead success was achieved in 95.2% of leads (n=220) and in 95.6% of patients (n=216). Major complications occurred in 5 patients (2.2%). Patients who had the CS lead extracted 1st had significantly higher incomplete removal rates than when the other leads were 1st removed. Multivariable analysis showed that older CS lead age (OR 1.35, 95% CI 1.01-1.82; P = 0.03), and removing the CS lead 1st (OR 7.48, 95% CI 1.02-54.95; P = 0.045) were independent predictors of incomplete CS lead removal.

CONCLUSION

Complete and safe lead removal rate of long implant duration CS leads by TLE was 95%. However, CS lead age and the order that leads were extracted were the independent predictors of incomplete CS lead removal. Therefore, before the CS lead is extracted, physicians should first extract the leads from the other chambers and employ powered sheaths.

Ablation of Atrial Fibrillation Without Left Atrial Appendage Imaging in Patients Treated With Direct Oral Anticoagulants

Background:

Many centers continue to routinely perform transesophageal echocardiograms before atrial fibrillation (AF) ablation procedures in patients treated with direct oral anticoagulants (DOACs). One study suggested that the procedures could be done without transesophageal echocardiogram but used intracardiac echocardiography imaging of the appendage from the right ventricular outflow. This study aimed to assess the safety of ablation for AF without transesophageal echocardiogram screening or intracardiac echocardiography imaging of the appendage in DOAC compliant patients.

Methods:

All patients undergoing AF ablation at the Cleveland Clinic (2011–2018) were enrolled in a prospectively maintained data registry. All consecutive patients presenting with AF or atrial flutter on DOAC were included. Periprocedural thromboembolic complications were assessed.

Results:

A total of 900 patients were included. Their median CHA 2 DS 2 -VASc score was 2 (interquartile range 1–3). All were on DOACs (333 rivaroxaban, 285 dabigatran, 281 apixaban, and 1 edoxaban). Thromboembolic complications occurred in 4 patients (0.3%): 2 ischemic strokes, 1 transient ischemic attack without residual deficit, and 1 splenic infarct; all with no further complications. Bleeding complications occurred in 5 patients (0.4%): 2 pericardial effusions (1 intraoperative, 1 after 30 days, both drained), 3 groin hematomas (1 of them due to needing heparin for venous thrombosis, none required interventions). No patients required emergent surgeries.

Conclusions:

In DOAC compliant patients who present for ablation in AF/atrial flutter, the procedures could be performed without transesophageal echocardiogram screening or intracardiac echocardiography imaging of the appendage; with low risk of complications.

Clinical Outcomes and Characteristics With Dofetilide in Atrial Fibrillation Patients Considered for Implantable Cardioverter-Defibrillator

BACKGROUND

Dofetilide is one of the only anti-arrhythmic agents approved for atrial fibrillation (AF) in patients with reduced left ventricular ejection fraction (LVEF). However, postapproval data and safety outcomes are limited. In this study, we assessed the incidence and predictors of LVEF improvement, safety, and outcomes in patients with AF with LVEF ≤35% without prior implantable cardioverter defibrillator, cardiac resynchronization therapy, or AF ablation.

METHODS

An analysis of 168 consecutive patients from 2007 to 2016 was performed. Incidences of adverse events, drug continuation, implantable cardioverter defibrillator and cardiac resynchronization therapy implantation, LVEF improvement (>35%) and recovery (≥50%), AF recurrence, and AF ablation were determined. Multivariable regression analysis to identify predictors of LVEF improvement/recovery was performed.

RESULTS

The mean age was 64±12 years. Dofetilide was discontinued before hospital discharge in 46 (27%) because of QT prolongation (14%), torsades de pointe or polymorphic ventricular tachycardia/fibrillation (6% [sustained 3%, nonsustained 3%]), ineffectiveness (5%), or other causes (3%). At 1 year, 43% remained on dofetilide. Freedom from AF was 42% at 1 year, and 40% underwent future AF ablation. LVEF recovered (≥50%) in 45% and improved to >35% in 73%. Predictors of LVEF improvement included presence of AF during echocardiogram (odds ratio, 4.22 [95% CI, 1.71-10.4], P=0.002), coronary artery disease (odds ratio, 0.35 [95% CI, 0.16-0.79], P=0.01), left atrial diameter (odds ratio, 0.52 per 1 cm increase [95% CI, 0.30-0.90], P=0.01), and LVEF (odds ratio, per 1% increase, 1.09 [95% CI, 1.02-1.16], P=0.006). The C statistic was 0.78.

CONCLUSIONS

In patients with LVEF ≤35%, who are potential implantable cardioverter defibrillator candidates, treated with dofetilide as an initial anti-arrhythmic strategy for AF, drug discontinuation rates were high, and many underwent future AF ablation. However, most patients had improvement in LVEF, obviating the need for primary prevention implantable cardioverter defibrillator.

Catheter Ablation in Patients With Cardiogenic Shock and Refractory Ventricular Tachycardia

BACKGROUND

There is paucity of data regarding radiofrequency ablation for ventricular tachycardia (VT) in patients with cardiogenic shock and concomitant VT refractory to antiarrhythmic drugs on mechanical support.

METHODS

Patients undergoing VT ablation at our center were enrolled in a prospectively maintained registry and screened for the current study (2010-2017).

RESULTS

All 21 consecutive patients with cardiogenic shock and concomitant refractory ventricular arrhythmia undergoing bailout ablation due to inability to wean off mechanical support were included. Median age was 61 years, 86% were men, median left ventricular ejection fraction was 20%, 81% had ischemic cardiomyopathy, and PAINESD score was 18±5. The type of mechanical support in place before the procedure was intra-aortic balloon pump in 14 patients (67%), Impella CP in 2, extracorporeal membrane oxygenation in 2, extracorporeal membrane oxygenation and intra-aortic balloon pump in 2, and extracorporeal membrane oxygenation and Impella CP in 1. Endocardial voltage maps showed myocardial scar in 19 patients (90%). The clinical VTs were inducible in 13 patients (62%), whereas 6 patients had premature ventricular contraction-induced ventricular fibrillation/VT (29%), and VT could not be induced in 2 patients (9%). Activation mapping was possible in all 13 with inducible clinical VTs. Substrate modification was performed in 15 patients with scar (79%). After ablation and scar modification, the arrhythmia was noninducible in 19 patients (91%). Seventeen (81%) were eventually weaned off mechanical support successfully, but 6 (29%) died during the index admission from persistent cardiogenic shock. Patients who had ventricular arrhythmia and cardiogenic shock on presentation had a trend toward lower in-hospital mortality compared with those who presented with cardiogenic shock and later developed ventricular arrhythmia.

CONCLUSIONS

Bailout ablation for refractory ventricular arrhythmia in cardiogenic shock allowed successful weaning from mechanical support in a large proportion of patients. Mortality remains high, but the majority of patients were discharged home and survived beyond 1 year.

Transvenous Lead Extraction in Patients With Arrhythmogenic Right Ventricular Cardiomyopathy

OBJECTIVES

This study aimed to evaluate the effectiveness and safety of transvenous lead extraction (TLE) in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC).

BACKGROUND

ARVC is an increasingly diagnosed cardiomyopathy that often requires device implantation to prevent sudden death. Little is known about TLE in this setting, which has potential challenges and risks, primarily due to right ventricular (RV) wall thinning and fragility.

METHODS

All consecutive patients with ARVC who underwent TLE at our institution between 1996 and 2016 were included. When extraction tools were used, sheaths were advanced to the RV with countertraction at the lead tip. Success and complications were defined in concordance with Heart Rhythm Society guidelines.

RESULTS

Twenty-two TLE procedures in patients with ARVC involved extraction of 27 leads (22 defibrillators and 5 pacemakers). TLEs were performed due to evidence of lead malfunction (n = 17; 77%) or device infection (n = 5; 23%). Twenty-four leads (89%) were RV, and 3 leads (11%) were right atrial. The median age of the oldest extracted lead was 1,691 days (interquartile range [IQR]: 1,168 to 2,726 days). Specialized extraction tools were required in 20 procedures (91%). None required the use of a snare or a femoral workstation. The median procedural and fluoroscopic times were 152 min (IQR: 129 to 185 min) and 11 min (IQR: 6 to 18 min), respectively. Complete procedural success with removal of all leads was achieved in all cases. There were no major complications.

CONCLUSIONS

In a high-volume center, TLE in patients with ARVC was associated with a high success rate and a low rate of complications when guideline-established techniques and tools were used.

Cardiac Implantable Electronic Device Infections: Added Complexity and Suboptimal Outcomes With Previously Abandoned Leads

OBJECTIVES

This study sought to assess the impact of previously abandoned leads on the clinical management of cardiac device infections, notably transvenous lead extraction and subsequent clinical course.

BACKGROUND

The population of patients with cardiac implantable electronic devices continues to grow with a disproportionate increase in device infections, which are invariably life threatening. A potentially complicating issue is the widely practiced strategy of device lead abandonment at the time of system revision, change, or upgrade, which is affecting an increasing number of patients.

METHODS

The study assessed the impact of previously abandoned leads in a prospectively maintained registry of consecutive patients undergoing percutaneous extraction of infected cardiac devices at the Cleveland Clinic between August 1996 and September 2012. The primary clinical endpoint was complete procedural and clinical success defined as the successful removal of the device and all lead material from the vascular space, in the absence of a major complication.

RESULTS

Of 1,386 patients with infected cardiac devices, 323 (23.3%) had previously abandoned leads. Failure to achieve the primary endpoint occurred more frequently in patients with abandoned leads (13.0% vs. 3.7%; p < 0.0001). This was primarily due to retention of lead material (11.5% vs. 2.9%; p < 0.0001), which was associated with poor clinical outcomes including higher rates of 1-month mortality (7.4% vs. 3.5% in those without lead remnants). Lead extraction procedures in patients with previously abandoned leads were longer (p < 0.0001), with longer fluoroscopy times (p < 0.0001), and more likely to require specialized extraction tools (94.4% vs. 81.8%; p < 0.0001) or adjunctive rescue femoral workstations (14.9% vs. 2.9%; p < 0.0001). Procedural complications occurred more frequently in patients with previously abandoned leads (11.5% vs. 5.6%; p = 0.0003), which was true for both major (3.7% vs. 1.4%; p = 0.009) and minor complications (7.7% vs. 4.4%; p = 0.02).

CONCLUSIONS

Previously abandoned leads complicate the management of cardiac device infections, leading to worse clinical outcomes.

Radiofrequency Ablation of Persistent Atrial Fibrillation: Diagnosis-to-Ablation Time, Markers of Pathways of Atrial Remodeling, and Outcomes

BACKGROUND

Various ablation strategies of persistent atrial fibrillation (PersAF) have had disappointing outcomes, despite concerted clinical and research efforts, which could reflect progressive atrial fibrillation-related atrial remodeling.

METHODS AND RESULTS

Two-year outcomes were assessed in 1241 consecutive patients undergoing first-time ablation of PersAF (2005-2012). The time intervals between the first diagnosis of PersAF and the ablation procedures were determined. Patients had echocardiograms and measures of B-type natriuretic peptide and C-reactive protein before the procedures. The median diagnosis-to-ablation time was 3 years (25th-75th percentiles 1-6.5). With longer diagnosis-to-ablation time (based on quartiles), there was a significant increase in recurrence rates in addition to an increase in B-type natriuretic peptide levels (P=0.01), C-reactive protein levels (P<0.0001), and left atrial size (P=0.03). The arrhythmia recurrence rates over 2 years were 33.6%, 52.6%, 57.1%, and 54.6% in the first, second, third, and fourth quartiles, respectively (P(categorical)<0.0001). In Cox Proportional Hazard analyses, B-type natriuretic peptide levels, C-reactive protein levels, and left atrial size were associated with arrhythmia recurrence. The diagnosis-to-ablation time had the strongest association with the ablation outcomes which persisted in multivariable Cox analyzes (hazard ratio for recurrence per +1Log diagnosis-to-ablation time 1.27, 95% confidence interval 1.14-1.43; P<0.0001; hazard ratio fourth versus first quartile 2.44, 95% confidence interval 1.68-3.65; P(categorical)<0.0001).

CONCLUSIONS

In patients with PersAF undergoing ablation, the time interval between the first diagnosis of PersAF and the catheter ablation procedure had a strong association with the ablation outcomes, such as shorter diagnosis-to-ablation times were associated with better outcomes and in direct association with markers of atrial remodeling.

Clinical reappraisal of SHORT syndrome with PIK3R1 mutations: toward recommendation for molecular testing and management

SHORT syndrome has historically been defined by its acronym: short stature (S), hyperextensibility of joints and/or inguinal hernia (H), ocular depression (O), Rieger abnormality (R) and teething delay (T). More recently several research groups have identified PIK3R1 mutations as responsible for SHORT syndrome. Knowledge of the molecular etiology of SHORT syndrome has permitted a reassessment of the clinical phenotype. The detailed phenotypes of 32 individuals with SHORT syndrome and PIK3R1 mutation, including eight newly ascertained individuals, were studied to fully define the syndrome and the indications for PIK3R1 testing. The major features described in the SHORT acronym were not universally seen and only half (52%) had four or more of the classic features. The commonly observed clinical features of SHORT syndrome seen in the cohort included intrauterine growth restriction (IUGR) <10th percentile, postnatal growth restriction, lipoatrophy and the characteristic facial gestalt. Anterior chamber defects and insulin resistance or diabetes were also observed but were not as prevalent. The less specific, or minor features of SHORT syndrome include teething delay, thin wrinkled skin, speech delay, sensorineural deafness, hyperextensibility of joints and inguinal hernia. Given the high risk of diabetes mellitus, regular monitoring of glucose metabolism is warranted. An echocardiogram, ophthalmological and hearing assessments are also recommended.

Survival of patients with biventricular devices after device infection, extraction, and reimplantation

OBJECTIVES

This study sought to compare outcomes in patients with biventricular device infections who undergo successful treatment including extraction and reimplantation to patients with biventricular devices never known to become infected.

BACKGROUND

Infection of a cardiac implantable electronic device (CIED) is associated with substantial morbidity and mortality. Survival in patients with cardiac resynchronization therapy (CRT) device infections undergoing full system extraction is unknown.

METHODS

We extracted data on all patients undergoing extraction of a biventricular pacing device for an infectious indication at the Cleveland Clinic between February 16, 2000, and June 30, 2011. Survival of patients who presented with a CRT device infection, extraction, and successful reimplantation was compared to that of a large cohort of consecutive patients undergoing initial CRT implantation without a known history of subsequent device-related infection. In addition, long-term outcomes were compared between patients who were extracted and deemed to be cured with and without successful biventricular device reimplantation.

RESULTS

In all, 151 patients underwent biventricular device extraction for infection, of whom 81 were successfully reimplanted. The noninfected cohort consisted of 879 patients. In a multivariate Cox regression model controlling for sex, a history of ischemic cardiomyopathy, creatinine, hemoglobin, beta-blocker use, angiotensin-converting enzyme inhibitor use, and diuretic use, no significant association between subsequent infection with reimplantation and all-cause mortality was noted (p = 0.21). There was a trend toward worse outcomes for patients extracted, deemed cured, and not reimplanted compared to patients with successful CRT reimplantation.

CONCLUSIONS

Patients with a biventricular device infection who are successfully extracted, treated with antibiotics, and reimplanted with a biventricular device have outcomes similar to those of patients with biventricular devices not known to have become infected.

Clinical response with adaptive CRT algorithm compared with CRT with echocardiography-optimized atrioventricular delay: a retrospective analysis of multicentre trials

AIMS

Adaptive cardiac resynchronization therapy (aCRT) is a novel algorithm for CRT pacing that provides automatic ambulatory selection between synchronized left ventricular (LV) or bi-ventricular (BiV) pacing and optimization of atrioventricular (AV) and inter-ventricular (VV) delays based on periodic measurement of intrinsic conduction. We aimed to compare the clinical response between aCRT and standard CRT in historical trials.

METHODS AND RESULTS

The treatment arm of the aCRT trial was compared with a pooled historical control (HC) derived from the CRT arms of four clinical trials (MIRACLE, MIRACLE ICD, PROSPECT, and InSync III Marquis) with respect to the proportion of patients who had an improved clinical composite score (CCS) at the 6-month follow-up. Patients in the HC underwent echocardiography-guided AV optimization after the implant. A propensity score model was used to adjust for 22 potential baseline confounders of the effect of CRT. Patients were stratified into quintiles according to the propensity score and the adjusted absolute treatment effect was obtained by averaging estimates across these quintiles. The propensity score model included 751 patients (aCRT: 266, historical trials: 485). The adjusted absolute difference in percent improved in CCS between the aCRT and HC arms was 11.9% [95% confidence interval (CI): 2.7-19.2%] favouring aCRT. The patients in the aCRT group were significantly more likely to have an improved CCS than the patients in the HC (odds ratio = 1.65, 95% CI: 1.1-2.5).

CONCLUSION

The aCRT algorithm may be associated with additional improvement in clinical response compared with historical CRT with echocardiographic AV optimization.

Clinical outcomes with synchronized left ventricular pacing: analysis of the adaptive CRT trial

BACKGROUND

Acute studies have suggested that left ventricular pacing (LVP) may have benefits over biventricular pacing (BVP). The adaptive cardiac resynchronization therapy (aCRT) algorithm provides LVP synchronized to produce fusion with the intrinsic activation when the intrinsic atrioventricular (AV) interval is normal. The randomized double-blind adaptive cardiac resynchronization therapy trial demonstrated noninferiority of the aCRT algorithm compared to echocardiography-optimized BVP (control).

OBJECTIVE

To examine whether synchronized LVP (sLVP) resulted in better clinical outcomes.

METHODS

First, stratification by percent sLVP (%sLVP) and multivariate Cox proportional hazards model was used to assess the relationship between %sLVP and clinical outcomes. Second, outcomes were compared between patients in the aCRT arm (n = 318) and control patients (n = 160) stratified by intrinsic AV interval at randomization.

RESULTS

In the aCRT arm, %sLVP ≥50% (n = 142) was independently associated with a decreased risk of death or heart failure hospitalization (hazard ratio 0.49; 95% confidence interval 0.28-0.85; P = .012) compared with %sLVP <50% (n = 172). A greater proportion of patients with %sLVP ≥50% improved in Packer's clinical composite score at 6-month (82% vs. 68%; P = .002) and 12-month (80% vs. 62%; P = .0006) follow-ups compared to controls. In the subgroup with normal AV (n = 241), there was a lower risk of death or heart failure hospitalization (hazard ratio 0.52; 95% confidence interval 0.27-0.98; P = .044) with the aCRT algorithm. A greater proportion of patients in the aCRT arm improved in the clinical composite score at 6-month (81% vs. 69%; P = .041) and 12-month (77% vs. 66%; P = .076) follow-ups compared to controls.

CONCLUSIONS

Higher %sLVP was independently associated with superior clinical outcomes. In patients with normal AV conduction, the aCRT algorithm provided mostly sLVP and demonstrated better clinical outcomes compared to echocardiography-optimized BVP.

Use of dabigatran for periprocedural anticoagulation in patients undergoing catheter ablation for atrial fibrillation

BACKGROUND

Pulmonary vein isolation (PVI) for atrial fibrillation is associated with a transient increased risk of thromboembolic and hemorrhagic events. We hypothesized that dabigatran can be safely used as an alternative to continuous warfarin for the periprocedural anticoagulation in PVI.

METHODS AND RESULTS

A total of 999 consecutive patients undergoing PVI were included; 376 patients were on dabigatran (150 mg), and 623 patients were on warfarin with therapeutic international normalized ratio. [corrected] Dabigatran was held 1 to 2 doses before PVI and restarted at the conclusion of the procedure or as soon as patients were transferred to the nursing floor. Propensity score matching was applied to generate a cohort of 344 patients in each group with balanced baseline data. Total hemorrhagic and thromboembolic complications were similar in both groups, before (3.2% versus 3.9%; P=0.59) and after (3.2% versus 4.1%; P=0.53) matching. Major hemorrhage occurred in 1.1% versus 1.6% (P=0.48) before and 1.2% versus 1.5% (P=0.74) after matching in the dabigatran versus warfarin group, respectively. A single thromboembolic event occurred in each of the dabigatran and warfarin groups. Despite higher doses of intraprocedural heparin, the mean activated clotting time was significantly lower in patients who held dabigatran for 1 or 2 doses than those on warfarin.

CONCLUSIONS

Our study found no evidence to suggest a higher risk of thromboembolic or hemorrhagic complications with use of dabigatran for periprocedural anticoagulation in patients undergoing PVI compared with uninterrupted warfarin therapy.

Endoscopic findings in upper gastrointestinal bleeding patients at Lacor hospital, northern Uganda

BACKGROUND

Upper gastrointestinal bleeding (UGIB) is a common emergency medical condition that may require hospitalization and resuscitation, and results in high patient morbidity. Upper gastrointestinal endoscopy is the preferred investigative procedure for UGIB because of its accuracy, low rate of complication, and its potential for therapeutic interventions.

OBJECTIVE

To determine the endoscopic findings in patients presenting with UGIB and its frequency among these patients according to gender and age in Lacor hospital, northern Uganda.

METHODS

The study was carried out at Lacor hospital, located at northern part of Uganda. The record of 224 patients who underwent endoscopy for upper gastrointestinal bleeding over a period of 5 years between January 2006 and December 2010 were retrospectively analyzed.

RESULTS

A total of 224 patients had endoscopy for UGIB which consisted of 113 (50.4%) males and 111 (49.6%) females, and the mean age was 42 years ± SD 15.88. The commonest cause of UGIB was esophagealvarices consisting of 40.6%, followed by esophagitis (14.7%), gastritis (12.6%) and peptic ulcer disease (duodenal and gastric ulcers) was 6.2%. The malignant conditions (gastric and esophageal cancers) contributed to 2.6%. Other less frequent causes of UGIB were hiatus hernia (1.8), duodenitis (0.9%), others-gastric polyp (0.4%). Normal endoscopic finding was 16.1% in patients who had UGIB.

CONCLUSIONS

Esophageal varices are the commonest cause of upper gastrointestinal bleeding in this environment as compared to the west which is mainly peptic ulcer disease.

Remote monitoring of cardiovascular devices: a time and activity analysis

BACKGROUND

Expanding indications for cardiovascular implantable electronic devices are accompanied by an increasing burden of device clinic follow-up. Remote monitoring (RM) may be less time-consuming compared to in-office follow-up; however, its effect on the device clinic workflow has not been clarified.

OBJECTIVE

To determine the impact of RM on device clinic workflow.

METHODS

Detailed workflow data were prospectively collected over a 2-week period in a busy device clinic.

RESULTS

Five hundred remote transmissions were received from 434 patients between March 1 and March 16, 2011--346 implantable cardioverter-defibrillator, 84 pacemaker, and 70 implantable loop recorder transmissions--on 4 RM platforms (CareLink 56.4%, Merlin.net 21.4%, LATITUDE 17.8%, and Home Monitoring 4.4%). The mean time spent per transmission was 11.5 ± 7.7 minutes, which was less than in-person interrogations (27.7 ± 9.9 minutes; P <.01). Of 500 transmissions, 135 (27.0%) demonstrated clinically important findings; however, only 41 (8.2%) were forwarded for physician review. Of 500 transmissions, 138 (27.6%) were unscheduled, and these were more likely to contain a clinically important event (56 of 138 [40.6%] vs 79 of 362 [21.8%]; P = .0001). A total of 5.8% of the transmissions were duplicate. Transmissions that revealed clinically important findings took longer to process than those that did not (21.0 ± 7.4 minutes vs 10.1 ± 2.1 minutes; P <.05). A total of 49.2% of the scheduled remote transmissions were missed because of patient noncompliance. Telephone follow-up of patients (mean 21 patients/d) who missed scheduled remote transmissions took a mean of 55.1 (range 20-98) min/d.

CONCLUSIONS

Analysis of RM transmissions has significant implications for the device clinic workflow. Nonactionable transmissions are rapidly processed, allowing clinicians to focus on clinically important findings. However, poor patient compliance complicates the workflow efficiency of currently available systems.

Investigation of a novel algorithm for synchronized left-ventricular pacing and ambulatory optimization of cardiac resynchronization therapy: results of the adaptive CRT trial

BACKGROUND

In patients with sinus rhythm and normal atrioventricular conduction, pacing only the left ventricle with appropriate atrioventricular delays can result in superior left ventricular and right ventricular function compared with standard biventricular (BiV) pacing.

OBJECTIVE

To evaluate a novel adaptive cardiac resynchronization therapy ((aCRT) algorithm for CRT pacing that provides automatic ambulatory selection between synchronized left ventricular or BiV pacing with dynamic optimization of atrioventricular and interventricular delays.

METHODS

Patients (n = 522) indicated for a CRT-defibrillator were randomized to aCRT vs echo-optimized BiV pacing (Echo) in a 2:1 ratio and followed at 1-, 3-, and 6-month postrandomization.

RESULTS

The study met all 3 noninferiority primary objectives: (1) the percentage of aCRT patients who improved in their clinical composite score at 6 months was at least as high in the aCRT arm as in the Echo arm (73.6% vs 72.5%, with a noninferiority margin of 12%; P = .0007); (2) aCRT and echo-optimized settings resulted in similar cardiac performance, as demonstrated by a high concordance correlation coefficient between aortic velocity time integrals at aCRT and Echo settings at randomization (concordance correlation coefficient = 0.93; 95% confidence interval 0.91-0.94) and at 6-month postrandomization (concordance correlation coefficient = 0.90; 95% confidence interval 0.87-0.92); and (3) aCRT did not result in inappropriate device settings. There were no significant differences between the arms with respect to heart failure events or ventricular arrhythmia episodes. Secondary end points showed similar benefit, and right-ventricular pacing was reduced by 44% in the aCRT arm.

CONCLUSIONS

The aCRT algorithm is safe and at least as effective as BiV pacing with comprehensive echocardiographic optimization.

Implantable cardioverter-defibrillator FDA safety advisories: Impact on patient mortality and morbidity

BACKGROUND

A significant proportion of implantable cardioverter-defibrillators (ICDs) have been subject to Food and Drug Administration (FDA) advisories. The impact of device advisories on mortality or patient care is poorly understood. Although estimated risks of ICD generators under advisory are low, dependency on ICD therapies to prevent sudden death justifies the assessment of long-term mortality.

OBJECTIVE

To test the association of FDA advisory status with long-term mortality.

METHODS

The study was a retrospective, single-center review of clinical outcomes, including device malfunctions, in patients from implantation to either explant or death. Patients with ICDs first implanted at Cleveland Clinic between August 1996 and May 2004 who became subject to FDA advisories on ICD generators were identified. Mortality was determined by using the Social Security Death Index.

RESULTS

In 1644 consecutive patients receiving first ICD implants, 704 (43%) became subject to an FDA advisory, of which 172 (10.5%) were class I and 532 (32.3%) were class II. ICDs were explanted before advisory notifications in 14.0% of class I and 10.1% of class II advisories. Among ICDs under advisory, 28 (4.0%) advisory-related and 15 non-advisory- related malfunctions were documented. Over a median follow-up of 70 months, 814 patients died. Kaplan-Meier 5-year survival rate was 65.6% overall, and 64.2, 61.1, and 69.3% in patients with no, class I, and class II advisories, respectively (P = .17).

CONCLUSIONS

ICD advisories impacted 43% of the patients. Advisory-related malfunctions affected 4% within the combined advisory group. Based on a conservative management strategy, ICDs under advisory were not associated with increased mortality over a background of significant disease-related mortality.

Predictors of response to cardiac resynchronization therapy in patients with a non-left bundle branch block morphology

Patients with non-left bundle branch block (LBBB) morphologies are thought to derive less benefit from cardiac resynchronization therapy (CRT) than those with LBBB. However, some patients do exhibit improvement. The characteristics associated with a response to CRT in patients with non-LBBB morphologies are unknown. Clinical, electrocardiographic, and echocardiographic data were collected from 850 consecutive patients presenting for a new CRT device. For inclusion, all patients had a left ventricular ejection fraction of ≤35%, a QRS duration of ≥120 ms, and baseline and follow-up echocardiograms available. Patients with a paced rhythm or LBBB were excluded. The response was defined as an absolute decrease in left ventricular end-systolic volume of ≥10% from baseline. Multivariate models were constructed to identify variables significantly associated with the response and long-term outcomes. A total of 99 patients met the inclusion criteria. Of these 99 patients, 22 had right bundle branch block and 77 had nonspecific intraventricular conduction delay; 52.5% met the criteria for response. On multivariate analysis, the QRS duration was the only variable significantly associated with the response (odds ratio per 10-ms increase 1.23, 95% confidence interval 1.01 to 1.52, p = 0.048). During a mean follow-up of 5.4 ± 0.9 years, 65 patients died or underwent heart transplant or left ventricular assist device placement. On multivariate analysis, the QRS duration was inversely associated with poor long-term outcomes (hazard ratio per 10-ms increase 0.79, 95% confidence interval 0.66 to 0.94, p = 0.005). In patients with advanced heart failure and non-LBBB morphologies, a wider baseline QRS duration is an important determinant of enhanced reverse ventricular remodeling and improved long-term outcomes after CRT.

The impact of left ventricular size on response to cardiac resynchronization therapy

Patients with nondilated (NDCM) or severely dilated cardiomyopathies (SDCM) have been underrepresented in clinical trials of cardiac resynchronization therapy (CRT). We examined changes in left ventricular ejection fraction (LVEF) and survival in patients with NDCM or SDCM compared with those with traditionally studied moderately dilated cardiomyopathy.

METHODS

We evaluated 800 consecutive patients undergoing the original implantation of a biventricular pacemaker between January 2004 and August 2007. For inclusion, patients had a baseline and pre-CRT echocardiogram, an LVEF ≤40%, a US social security number, and New York Heart Association class II to IV symptoms on standard medical therapy. Patients with a follow-up echocardiogram >2 months after device implantation were included in an analysis of remodeling. Using multivariate models, the impact of baseline left ventricular end-diastolic diameter (LVEDD) on change in LVEF and all-cause mortality was assessed.

RESULTS

A total of 668 patients met inclusion criteria and were included in the assessment of mortality. Four hundred seventy-one had an appropriately timed follow-up echocardiogram and were included in the analysis of remodeling. Patients in all 3 groups realized improvements in LVEF (%) after CRT as follows: NDCM (n = 137; LVEDD ≤5.5 cm) 10.0 ± 12.7, P < .001; moderately dilated cardiomyopathy (n = 233; LVEDD 5.6-6.9 cm) 8.2 ± 11.3, P < .001; and SDCM (n = 101; LVEDD ≥7.0 cm) 5.4 ± 9.4, P < .001. In multivariate analysis, baseline LVEDD was inversely associated with change in LVEF (parameter estimate -3.13 ± 0.56, P < .001) and directly associated with increased all-cause mortality (hazard ratio 1.25 [1.05-1.47] P = .01).

CONCLUSION

Patients with NDCM and SDCM experience significant improvements in LVEF after CRT. The degree of baseline left ventricular dilatation before CRT is an important predictor of subsequent changes in LVEF and survival.

QRS fragmentation is not associated with poor response to cardiac resynchronization therapy

BACKGROUND

QRS fragmentation (fQRS) has been shown to be a marker of scar in patients with left ventricular dysfunction. Whether fQRS is associated with progressive left ventricular remodeling and increased mortality in patients receiving cardiac resynchronization therapy (CRT) is unclear.

METHODS

We reviewed the preimplant and follow-up echocardiograms in 233 patients undergoing the new implantation of a CRT device between December 2001 and November 2006. Patients were included if they had a pre-CRT ECG with appropriate filter settings (filter 0.16-100 or 0.16-150 Hz, 25 mm/s, 10 mm/mV), a left ventricular ejection fraction (LVEF) ≤40%, and New York Heart Association class II-IV symptoms on standard medical therapy. The 12-lead electrocardiogram (ECG) was interpreted by two blinded reviewers for the presence of fQRS. Remodeling end points, including changes in LVEF and left ventricular end-diastolic (LVEDV) and systolic (LVESV) volumes, were compared between patients with and without contiguous fQRS, and an assessment of all-cause mortality was made.

RESULTS

Two hundred thirty-two patients met inclusion criteria, of which 50 demonstrated fQRS in contiguous leads. There was no difference in improvement in LVEF (%) (7.9 ± 12.9 vs 6.8 ± 11.0, P = 0.60) or reduction in LVEDV (mL) (-30.1 ± 57.2 vs -15.7 ± 47.6) or LVESV (mL) (-33.7 ± 58.1 vs -22.7 ± 50.6, P = 0.40) between patients with and without contiguous fQRS. At a mean follow-up of 4.4 ± 1.9 years, there were a total of 89 deaths, 22 (44.0%) in patients with contiguous fQRS and 67 (36.8%) without (log rank P = 0.31).

CONCLUSIONS

QRS fragmentation is not a predictor of progressive ventricular remodeling or mortality in heart failure patients undergoing CRT.

Utility of a novel watch-based pulse detection system to detect pulselessness in human subjects

BACKGROUND

The Wriskwatch is a novel, watch-based pulse detection device that detects the loss of a radial pulse via advanced pulse detection technology and immediately contacts emergency medical systems.

OBJECTIVE

The purpose of this first-in-man, prospective, single-blinded, phase 1 study was to evaluate the ability of this device to detect motionlessness and pulselessness in human subjects as a simulation of sudden cardiac death.

METHODS

The study cohort consisted of 34 patients: 24 hospitalized patients and 10 presenting for implantable cardioverter-defibrillator (ICD) testing. We simulated loss of pulse in our hospitalized patients via blood pressure cuff inflation to occlude the brachial arterial pulse at random times in 20 subjects with no inflations in 4 while the patients were instructed to keep perfectly still. Of the 10 patients undergoing ventricular fibrillation (VF) induction during ICD testing, the exact times of VF induction were recorded. A blinded reviewer determined if and when motion and pulse were lost in all patients using only data from the device.

RESULTS

Of the 34 patients, 2 had an unusable signal, 1 had device ejection during ICD testing, and 2 had too much motion artifact and were excluded (5/34 patients, or 14.7% of the total cohort). Of the 29 remaining subjects, 4 had no loss of pulse of which the device correctly identified 3. In the remaining 25 patients, the device correctly identified the time of pulselessness in 23 of 25 (16/17 hospitalized patients and 7/8 ICD patients). Overall, the Wriskwatch was worn for a total of 561.2 minutes. Pulselessness was present for 5.8 minutes. The sensitivity of the watch to detect pulse status (based on 15-second intervals) was 99.9%, and the specificity was 90.3%.

CONCLUSION

The Wriskwatch is a novel device that shows promise as a tool to hasten activation of emergency medical systems and facilitate early defibrillation in patients with cardiac arrest.

Natural History and Long-Term Outcomes of Ablated Atrial Fibrillation

Background—

Atrial fibrillation (AF) ablation is increasingly used in clinical practice. We aimed to study the natural history and long-term outcomes of ablated AF.

Methods and Results—

We followed 831 patients after pulmonary vein isolation (PVI) performed in 2005. We documented clinical outcomes using our prospective AF registry with most recent update on this group of patients in October 2009. In the first year after ablation, 23.8% had early recurrence. Over long-term follow-up (55 months), only 8.9% had late arrhythmia recurrence defined as occurring beyond the first year after ablation. Repeat ablations in patients with late recurrence revealed conduction recovery in at least 1 of the previously isolated PVs in all of them and right-sided triggers with isoproterenol testing in 55.6%. At last follow-up, clinical improvement was 89.9% (79.4% arrhythmia-free off antiarrhythmic drugs and 10.5% with AF controlled with antiarrhythmic drugs). Only 4.6% continued to have drug-resistant AF. It was possible to safely discontinue anticoagulation in a substantial proportion of patients with no recurrence in the year after ablation (CHADS score ≤2, stroke incidence of 0.06% per year). The procedure-related complication rate was very low.

Conclusions—

Pulmonary vein isolation is safe and efficacious for long-term maintenance of sinus rhythm and control of symptoms in patients with drug-resistant AF. It obviates the need for antiarrhythmic drugs, negative dromotropic agents, and anticoagulants in a substantial proportion of patients.

A randomized controlled trial of the efficacy and safety of electroanatomic circumferential pulmonary vein ablation supplemented by ablation of complex fractionated atrial electrograms versus potential-guided pulmonary vein antrum isolation guided by intracardiac ultrasound

BACKGROUND

The study was conducted to compare relative safety and efficacy of pulmonary vein antrum isolation (PVAI) using intracardiac echocardiographic guidance and circumferential pulmonary vein ablation (CPVA) for atrial fibrillation (AF) using radiofrequency energy.

METHODS AND RESULTS

Sixty patients (81% men; 81% paroxysmal; age, 56+/-8 years) failing 2+/-1 antiarrhythmic drugs were randomly assigned to undergo CPVA (n=30) or PVAI (n=30) at 5 centers between December 2004 and October 2007. CPVA patients had circular lesions placed at least 1 cm outside of the veins. Ipsilateral veins were ablated en block with the end point of disappearance of potentials within the circular lesion. Left atrial roof line and mitral isthmus line were ablated without verification of block. For patients in AF postablation or with AF induced with programmed stimulation, complex fractionated electrograms were mapped and ablated to the end point of AF termination or disappearance of complex fractionated electrograms. PVAI did not include complex fractionated electrogram ablation. Esophageal temperature was monitored and kept within 2 degrees C of baseline or under 39 degrees C. Success was defined as absence of atrial tachyarrhythmias (AF/AT) off antiarrhythmic drugs. There was no difference between CPVA and PVAI regarding to baseline variables, catheter used, duration of the procedure, or RF delivery. Fluoroscopy time was longer with PVAI (54+/-17 minutes versus 77+/-18 minutes, P=0.0001). No significant complications occurred in either arm. PVAI was more likely to achieve control of AF/AT off antiarrhythmic drugs (57% versus 27%, P=0.02) at 2+/-1 years of follow-up.

CONCLUSIONS

A single PVAI procedure is more likely to result in freedom from AF/AT off antiarrhythmic drugs than CPVA supplemented by complex fractionated electrogram ablation in select patients.

Microvolt T-wave alternans, peak oxygen consumption, and outcome in patients with severely impaired left ventricular systolic function

BACKGROUND

Abnormal microvolt T-wave alternans (MTWA) and low peak oxygen consumption (VO2) both predict poor outcome in heart failure. However, their independent predictive properties have not been assessed in large-scale cohorts.

METHODS

This was an observational prospective cohort study of 303 consecutive patients referred for metabolic stress testing. All had an ejection fraction < or = 40% and were considered candidates for transplantation. The exercise laboratory did not collect MTWA data from patients with implanted pacemakers or defibrillators. The primary end point was a composite of all-cause death or United Network for Organ Sharing status 1 transplantation.

RESULTS

During a 2.8-year period, there were 34 deaths and 17 transplantations. Patients with abnormal MTWA had a higher event rate of 23% (31 of 136) vs 12% (20 of 167), with an unadjusted hazard ratio (HR) of 1.90 (95% confidence interval [CI], 1.90-3.33; p = 0.03). The association remained significant after adjustment for 3 clinical variables (HR, 1.89; 95% CI, 1.05-3.39; p = 0.03). After adding peak VO2 to the model, the association was no longer significant (adjusted HR, 1.18; 95% CI, 0.64-2.17, p = 0.60). After accounting for peak VO2 and 28 other confounders in a matched propensity analysis, MTWA was not predictive (propensity-matched HR, 0.79; 95% CI, 0.37-1.66; p = 0.53).

CONCLUSIONS

These results confirm the association of abnormal MTWA with poor outcome amongst patients with impaired left ventricular systolic function. However, this association is markedly attenuated after accounting for peak VO2.