Implantable Cardioverter Defibrillator Programming Characteristics, Shocked Rhythms, and Survival Among Patients Under Thirty Years of Age.

INTRODUCTION: Indications for implantable cardioverter defibrillators (ICDs) in young patients have expanded and differ from those in older adults. We sought to provide descriptive characteristics and data regarding ICD therapy and outcomes among younger and older ICD recipients. METHODS AND RESULTS: Demographics, device type and programming, remotely transmitted data, shock events, and survival were compared among younger (≤30 years) and older (>30 years) cohorts with ICDs from a single manufacturer followed on a remote network. The younger cohort included 904 patients (1.6% of all implants). This group had more females (46% vs. 25%; P < 0.01), single-coil leads (21% vs. 4%; P < 0.01), and single-chamber devices (46% vs. 34%; P < 0.01). Shock incidence was higher (40% younger vs. 32% older at 4 years; P < 0.01) and survival was better over comparable follow-up (88% vs. 72%; P < 0.01). Remote monitoring was associated with improved survival in both groups (93% vs. 86% ≤ 30 years, P < 0.01; 73% vs. 66% > 30 years, P < 0.01). Shock for polymorphic ventricular tachycardia/fibrillation (VT/VF) was more frequent in younger patients (12% vs. 5%; P < 0.01); 39% of all shocks were inappropriate. A 10-fold increased risk of mortality was seen among young patients with shocks for atrial fibrillation/flutter (AF/AFL). CONCLUSIONS: Differences in survival, shock incidence, and prognostic significance of VT/VF and AF/AFL exist between younger and older ICD recipients. These suggest distinct differences in myocardial substrates and diseases that ultimately impact ICD management.

Recent Advances in the Pharmacological Management of Atrial Fibrillation.

Atrial fibrillation (AF) is a highly prevalent cardiac arrhythmia that leads to hospitalizations for complications and adverse events each year. Despite significant improvement in our therapeutic approaches in the past decade, management of AF remains a difficult task. Novel therapies have failed to terminate AF and prevent its recurrence, and patients with AF continue to have thromboembolic complications. With the increasingly aging population and associated conditions, the prevalence of AF is expected to progressively increase, becoming a public health problem. Most patients with AF have multiple comorbidities and are of advanced age, making long-term anticoagulation challenging. This article provides an overview of the current pharmacological therapies for the management of AF, with particular emphasis on the emerging agents.

Entrapment of a Pacing Lead within a Chiari Network: Utility of Intracardiac Echo and a Laser Sheath.

Although rare, Chiari networks are elaborate embryological remnants that can pose distinct challenges for catheter and pacing lead manipulation within the right atrium. Device entrapment may require open thoracotomy for removal, with significant morbidity. We report an unusual case of pacing lead entanglement within this structure, followed by prompt intracardiac echocardiographic identification and laser sheath removal.

Predictors and outcomes of "super-response" to cardiac resynchronization therapy.

BACKGROUND: Cardiac resynchronization therapy (CRT) has been shown to improve heart failure (HF) symptoms and survival. We hypothesized that a greater improvement in left-ventricular ejection fraction (LVEF) after CRT is associated with greater survival benefit. METHODS AND RESULTS: In 693 patients across 2 international centers, the improvement in LVEF after CRT was determined. Patients were grouped as non-/modest-, moderate-, or super-responders to CRT, defined as an absolute change in LVEF of ≤5%, 6-15%, and >15%, respectively. Changes in New York Heart Association (NYHA) functional class and left ventricular end-diastolic dimension (LVEDD) were assessed for each group. There were 395 non-/modest-, 186 moderate-, and 112 super-responders. Super-responders were more likely to be female and to have nonischemic cardiomyopathy, lower creatinine, and lower pulmonary artery systolic pressure than non-/modest- and moderate-responders. Super-responders were also more likely to have lower LVEF than non-/modest-responders. There was no difference in NYHA functional class, mitral regurgitation grade, or tricuspid regurgitation grade between groups. Improvement in NYHA functional class (-0.9 ± 0.9 vs -0.4 ± 0.8 [P < .001] and -0.6 ± 0.8 [P = .02]) and LVEDD (-8.7 ± 9.9 mm vs -0.5 ± 5.0 and -2.4 ± 5.8 mm [P < .001 for both]) was greatest in super-responders. Kaplan-Meier survival analysis revealed that super-responders achieved better survival compared with non-/modest- (P < .001) and moderate-responders (P = .049). CONCLUSIONS: Improvement in HF symptoms and survival after CRT is proportionate to the degree of improvement in LV systolic function. Super-response is more likely in women, those with nonischemic substrate, and those with lower pulmonary artery systolic pressure.

Performance of an automatic arrhythmia classification algorithm: comparison to the ALTITUDE electrophysiologist panel adjudications.

INTRODUCTION: Adjudication of thousands of implantable cardioverter defibrillator (ICD)-treated arrhythmia episodes is labor intensive and, as a result, is most often left undone. The objective of this study was to evaluate an automatic classification algorithm for adjudication of ICD-treated arrhythmia episodes. METHODS: The algorithm uses a machine learning algorithm and was developed using 776 arrhythmia episodes. The algorithm was validated on 131 dual-chamber ICD shock episodes from 127 patients adjudicated by seven electrophysiologists (EPs). Episodes were classified by panel consensus as ventricular tachycardia/ventricular fibrillation (VT/VF) or non-VT/VF, with the resulting classifications used as the reference. Subsequently, each episode electrogram (EGM) data was randomly assigned to three EPs without the atrial lead information, and to three EPs with the atrial lead information. Those episodes were also classified by the automatic algorithm with and without atrial information. Agreement with the reference was compared between the three EPs consensus group and the algorithm. RESULTS: The overall agreement with the reference was similar between three-EP consensus and the algorithm for both with atrial EGM (94% vs 95%, P = 0.87) and without atrial EGM (90% vs 91%, P = 0.91). The odds of accurate adjudication, after adjusting for covariates, did not significantly differ between the algorithm and EP consensus (odds ratio 1.02, 95% confidence interval: 0.97-1.06). CONCLUSIONS: This algorithm performs at a level comparable to an EP panel in the adjudication of arrhythmia episodes treated by both dual- and single-chamber ICDs. This type of algorithm has the potential for automated analysis of clinical ICD episodes, and adjudication of EGMs for research studies and quality analyses.

Percutaneous pacemaker or implantable cardioverter-defibrillator lead removal in an attempt to improve symptomatic tricuspid regurgitation.

AIMS: Pacemaker and implantable cardioverter-defibrillator (ICD) leads can cause tricuspid valve regurgitation (TR). Few data are available on the best management of significant TR that develops after pacemaker or ICD implantation and regarding any benefits of right ventricular (RV) lead extraction. We sought to determine the impact of RV lead removal on lead-induced TR. METHODS AND RESULTS: We reviewed all patients between 1 January 2000 and 31 December 2010 at the tertiary care hospital who had a preoperative indication of TR and underwent percutaneous extraction of an RV lead with the intent of trying to correct moderate or severe TR. Pre- and post-procedure echoes and clinical data were retrospectively reviewed. In the four patients identified, the RV lead was removed and placed in the coronary sinus to try to improve moderate or severe TR due to lead impingement. There was no significant improvement in the degree of TR except one patient where TR improved slightly from moderate to mild-moderate. All patients had a dilated tricuspid valve annulus by the time of lead extraction. Tricuspid annulus dilatation appeared to account for the persistent TR after RV lead removal. CONCLUSION: A greater degree of tricuspid valve annulus dilatation may be a marker and mechanism for irreversible lead-induced TR. Further studies are needed to determine whether surgical tricuspid valve repair or replacement combined with RV lead extraction would result in better outcomes than a percutaneous lead extraction approach.

Phase 4 paroxysmal AV block in a patient with scleroderma.

A 72-year-old man with limited cutaneous systemic scleroderma was hospitalized for two episodes of witnessed syncope. The baseline 12-lead electrocardiogram was normal but on telemetry there were numerous episodes of paroxysmal AV block with asystolic periods of up to 7.5 s duration. Analysis of the rhythm strips revealed phase 4 intra-His bundle block characterized by critical P-P intervals that triggered the AV block, and a narrow range of junctional escape to subsequent P wave intervals that were required to release the AV block. A dual chamber pacemaker was implanted.

Impact of radiocontrast use during left ventricular pacemaker lead implantation for cardiac resynchronization therapy.

AIMS: The risk of contrast-induced nephropathy (CIN) with radiocontrast use during left ventricular (LV) lead placement for cardiac resynchronization therapy (CRT) is unknown. It is unclear as to whether minimizing contrast use impacts adequacy of LV lead placement. METHODS AND RESULTS: A retrospective analysis was performed of all LV leads placed for CRT at Mayo Clinic, Rochester, MN from 16 March 2001 to 1 April 2009. The primary goal was to assess risk of CIN and adequacy of lead placement depending on the amount of contrast administered during CRT placement. Contrast-induced nephropathy was defined as a ≥25% increase in serum creatinine ≥48 h post-procedurally. Adequacy of lead placement was assessed in a blinded fashion by review of procedural fluoroscopic and post-procedural radiographic images. Eight hundred and twenty-two subjects were divided based on the amount of procedural contrast used into tertile 1 (<55 mL, 257 patients), tertile 2 (55-94 mL, 261 patients), and tertile 3 (≥95 mL, 304 patients). Contrast-induced nephropathy occurred in 5.4% of patients in tertile 1, 5.4% in tertile 2 and 11.8% in tertile 3 (P = 0.004). Among the tertiles, lead positioning was optimal in 95, 80 and 66%, respectively (P < 0.0001). Fluoroscopic time was 34 ± 23, 42 ± 26, and 48 ± 30 min in tertiles 1, 2, and 3 (P < 0.0001). CONCLUSION: Risk of CIN with CRT implantations was substantial. Increased volume of radiocontrast used for LV lead placement was associated with substantially increased risk of CIN. Minimal contrast use was associated with decreased procedural times without adverse impact on adequacy of lead placement.

Left ventricular lead position for cardiac resynchronization: a comprehensive cinegraphic, echocardiographic, clinical, and survival analysis.

AIMS: We sought to determine the clinical and survival outcomes of cardiac resynchronization therapy (CRT) associated with left ventricular (LV) lead location. The lateral left ventricle has been considered the optimal LV lead location for CRT. METHODS AND RESULTS: Left ventricular lead cinegrams taken in 30° right and left anterior oblique views were evaluated in 457 recipients of CRT with a pacemaker or a defibrillator from 1 January 2002 to 31 December 2008 in this retrospective study. Left ventricular lead placement was prioritized at implantation into posterolateral (PL), anterolateral (AL), middle cardiac, and anterointerventricular coronary veins. Using echocardiographic LV 16-segment analysis, we grouped the leads as anterior, AL, PL, and posterior locations. New York Heart Association (NYHA) class and echocardiography were assessed before and after CRT. Clinical and survival outcomes after CRT were compared among the four LV lead locations.  Patient baseline demographic characteristics were similar among these four groups. Improvement in NYHA class was significantly greater in the AL (P= 0.04) and PL (P= 0.03) locations than in the anterior location. There was a tendency for greater improvement in LV ejection fraction among the AL (P= 0.11) and PL (P= 0.08) locations than the anterior location. Kaplan-Meier survival estimate at 4 years varied for location: AL, 72%; anterior, 48%; PL, 62%; and posterior, 72% (P= 0.003). CONCLUSION: Cardiac resynchronization therapy recipients are profiting from all lead positions. However, LV lead placed in the AL and PL positions is more preferential for achieving optimal CRT benefit than leads placed in the anterior position.

Noise, artifact, and oversensing related inappropriate ICD shock evaluation: ALTITUDE noise study.

BACKGROUND: Approximately 12-21% of implantable cardioverter defibrillator (ICD) patients receive inappropriate shocks. We sought to determine the incidence and causes of noise/artifact and oversensing (NAO) resulting in ICD shocks. METHODS: A random sample of 2,000 patients who received ICD and cardiac resynchronization therapy defibrillator shocks and were followed by a remote monitoring system was included. Seven electrophysiologists analyzed stored electrograms from the 5,279 shock episodes. Episodes were adjudicated as appropriate or inappropriate shocks. RESULTS: Of the 5,248 shock episodes with complete adjudication, 1,570 (30%) were judged to be inappropriate shocks. Of these 1,570, 134 (8.5%) were a result of NAO. The 134 NAO episodes were determined to be due to external noise in 76 (57%), lead connector-related in 37 (28%), muscle noise in 11 (8%), oversensing of atrium in seven (5%), T-wave oversensing in two (2%), and other noise in one (1%). The ICD shock itself resulted in a marked decrease in the level of noise in 60 of 134 (45%) NAO episodes, and the magnitude of this effect varied with the type of NAO (58% for external noise, 35% for muscle, 27% for lead/connector, and 0% for oversensing; P = 0.03). There was no significant difference in NAO likelihood based on type of lead (integrated bipolar 89/1,802 vs dedicated bipolar 9/140, P = 0.67). CONCLUSIONS: External noise and lead/connector noise were the primary causes, while T-wave oversensing was the least common cause of NAO resulting in ICD shock. Noise/artifact decreased immediately after a shock in nearly half of episodes. The specific ICD lead type did not impact the likelihood of NAO.

Implantable cardioverter defibrillator electrogram adjudication for device registries: methodology and observations from ALTITUDE.

BACKGROUND: The increasing use of remote monitoring with the associated large retrievable databases provides a unique opportunity to analyze observations on implantable cardioverter-defibrillator (ICD) therapies. Adjudication of a large number of stored ICD electrograms (EGMs) presents a unique challenge. The ALTITUDE study group was designed to use the LATITUDE remote monitoring system to evaluate ICD patient outcomes across the United States. METHODS AND RESULTS: Of 81,081 patients on remote monitoring, a random sample of 2,000 patients having 5,279 shock episodes was selected. The ALTITUDE EGM review committee was comprised of seven electrophysiologists from four institutions. An online EGM adjudication system was designed. Episodes were classified as appropriate (70% of shock episodes) or inappropriate ICD therapies (30%). Light's Kappa was used to assess agreement. Interobserver and intraobserver Kappa scores for dual-chamber ICDs were 0.84 (0.71-0.91) and 0.89 (0.82-0.95), consistent with substantial agreement. Interobserver and intraobserver Kappa scores for single-chamber ICDs were 0.61 (0.54-0.67) and 0.69 (0.59-0.79). The rhythm categories of "nonsustained arrhythmia" and "polymorphic and monomorphic ventricular tachycardia" resulted in the greatest degree of discordant adjudication between reviewers. CONCLUSIONS: This method of adjudication of a large volume of stored EGM data prior to device therapies will allow new observations in regards to device performance and has the potential to improve device programming and design. There was substantial interreviewer agreement for rhythm classification. Agreement was greater for dual-chamber compared to single-chamber devices, indicating the atrial lead adds diagnostic value in rhythm interpretation.

No increased bleeding events with continuation of oral anticoagulation therapy for patients undergoing cardiac device procedure.

BACKGROUND: Switching warfarin for heparin has been a practice for managing periprocedural anticoagulation in high-risk patients undergoing device-related procedures. We sought to investigate whether continuation of warfarin sodium therapy without heparin bridging is safe and, when it is continued, the optimal international normalized ratio (INR) without increased bleeding risk at time of device-related procedure. METHODS AND RESULTS: We retrospectively studied 766 consecutive patients taking warfarin long term who underwent device-related procedures. Patients were grouped by treatment: discontinued warfarin (-warfarin, n = 243), no interruption of warfarin (+warfarin, n = 324), and discontinued warfarin with heparin bridging (+heparin, n = 199). The study primary endpoint was systemic bleeding or formation of moderate or severe pocket hematoma within 30 days of the procedure. Thirty-one (4%) patients had bleeding events, including pocket hematoma in 29 patients. The bleeding events occurred more often for +heparin (7.0%) than -warfarin (2.1%) or +warfarin (3.7%, P = 0.029). For +warfarin group, INR of 2.0-2.5 at time of procedure did not increase bleeding risk compared with INR less than 1.5 (3.7% vs 3.4%; P = 0.72), but INR greater than 2.5 increased the bleeding risk (10.0% vs 3.4%; P = 0.029). Concomitant aspirin use with warfarin significantly increased bleeding risk than warfarin alone (5.6% vs 1.4%, P = 0.02). Median length of hospitalization was significantly shorter for +warfarin than +heparin (1 vs 6 days; P < 0.001). CONCLUSION: Continuation of oral anticoagulation therapy with an INR level of <2.5 does not impose increased risk of bleeding for device-related procedures, although precaution is necessary to avoid supratherapeutic anticoagulation levels.

Anodal stimulation: an underrecognized cause of nonresponders to cardiac resynchronization therapy.

OBJECTIVE: The purpose of this study was to determine if anodal stimulation accounts for failure to benefit from cardiac resynchronization therapy (CRT) in some patients. BACKGROUND: Approximately 30-40% of patients with moderate to severe heart failure do not have symptomatic nor echocardiographic improvement in cardiac function following CRT. Modern CRT devices allow the option of programming left ventricular (LV) lead pacing as LV tip to right ventricular (RV) lead coil to potentially improve pacing thresholds. However, anodal stimulation can result in unintentional RV pacing (anode) instead of LV pacing (cathode). METHODS: Patients enrolled in our center's CRT registry had an echocardiogram, 6-minute walk (6MW), and Minnesota Living with HF Questionnaire (MLHFQ) pre-implant and 6 months after CRT. Electrocardiograms (12 lead) during RV, LV, and biventricular (BiV) pacing were obtained at the end of the implant in 102 patients. Anodal stimulation was defined as LV pacing QRS morphology on EKG being identical to RV pacing or consistent with fusion with RV and LV electrode capture. LV end systolic volume (LVESV) was measured by echo biplane Simpson's method and CRT responder was defined as 15% or greater reduction in LVESV. RESULTS: Of the 102 patients, 46 (45.1%) had the final LV lead pacing configuration programmed LV (tip or ring) to RV (coil or ring). 3 of the 46 subjects (6.5%) had EKG findings consistent with anodal stimulation, not corrected intraoperatively. All anodal stimulation patients were nonresponders to CRT by echo criteria (reduction in LVESV 13.3 ± 0.6%, increase in EF 5.0 ± 1.4%) compared to 46% responders for those without anodal stimulation, (change in LVESV 18.7 ± 25.6%, EF 7.6 ±10.9%). None of the anodal stimulation patients were responders for the 6 minute walk, compared to 32 of 66 (48%) of those without anodal stimulation. CONCLUSION: Anodal stimulation is a potential underrecognized and ameliorable cause of poor response to CRT.

Comparison of echocardiographic dyssynchrony assessment by tissue velocity and strain imaging in subjects with or without systolic dysfunction and with or without left bundle-branch block.

BACKGROUND: Several echocardiographic dyssynchrony indexes have been proposed to identify responders to cardiac resynchronization therapy using tissue velocity and strain. The present study aimed to compare tissue velocity-derived and strain-derived dyssynchrony indexes in patients with or without systolic dysfunction and left bundle-branch block. METHODS AND RESULTS: Tissue Doppler imaging was performed in 120 subjects divided into 4 groups: group 1 (n=40), normal subjects; group 2 (n=20), normal left ventricular ejection fraction and left bundle-branch block; group 3 (n=20), left ventricular ejection fraction <35% and normal conduction; and group 4 (n=40), left ventricular ejection fraction <35% and left bundle-branch block. Dyssynchrony indexes based on time to peak tissue velocity (septal-lateral delay, anteroseptal-posterior delay, and SD in time to peak systolic velocity in the 12 left ventricular segments) and strain (SD of time to peak strain in 12 segments) were measured. The SD in time to peak systolic velocity in the 12 left ventricular segments was greater in group 4 (54 ms; 25th and 75th percentiles, 46 to 64 ms) than group 1 (44 ms; 25th and 75th percentiles, 28 to 53 ms; P=0.006), but there was a considerable overlap of all tissue velocity-derived indexes among 4 groups, with 40% to 68% of group 1 having values proposed for predicting the responders of cardiac resynchronization therapy. The SD of time to peak strain in 12 segments distinguished these groups with much less overlap (P<0.01 for all pairwise comparisons). CONCLUSIONS: A substantial proportion of normal subjects have tissue velocity-derived dyssynchrony indexes higher than the cutoff value proposed for predicting beneficial effect of cardiac resynchronization therapy. Strain-derived timing index appears to be more specific for dyssynchrony in patients with systolic dysfunction and left bundle-branch block. Identifying an optimal tissue velocity- or strain-derived dyssynchrony index requires a large prospective clinical trial.

Substrate and procedural predictors of outcomes after catheter ablation for atrial fibrillation in patients with hypertrophic cardiomyopathy.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) is often accompanied by atrial fibrillation (AF) due to diastolic dysfunction, elevated left atrial pressure, and enlargement. Although catheter ablation for drug-refractory AF is an effective treatment, the efficacy in HCM remains to be established. METHODS: Thirty-three consecutive patients (25 male, age 51 +/- 11 years) with HCM underwent pulmonary vein (PV) isolation (n = 8) or wide area circumferential ablation with additional linear ablation (n = 25) for drug-refractory AF. Twelve-lead and 24-hour ambulating ECGs, echocardiograms, event monitor strips, and SF 36 quality of life (QOL) surveys were obtained before ablation and for routine follow-up. RESULTS: Twenty-one (64%) patients had paroxysmal AF and 12 (36%) had persistent/permanent AF for 6.2 +/- 5.2 years. The average ejection fraction was 0.63 +/- 0.12. The average left atrial volume index was 70 +/- 24 mL/m(2). Over a follow-up of 1.5 +/- 1.2 years, 1-year survival with AF elimination was 62%(Confidence Interval [CI]: 66-84) and with AF control was 75%(CI: 66-84). AF control was less likely in patients with a persistent/chronic AF, larger left atrial volumes, and more advanced diastolic disease. Additional linear ablation may improve outcomes in patient with severe left atrial enlargement and more advanced diastolic dysfunction. Two patients had a periprocedureal TIA, one PV stenosis, and one died after mitral valve replacement from prosthetic valve thrombosis. QOL scores improved from baseline at 3 and 12 months. CONCLUSION: Outcomes after AF ablation in patients with HCM are favorable. Diastolic dysfunction, left atrial enlargement, and AF subtype influence outcomes. Future studies of rhythm management approaches in HCM patients are required to clarify the optimal clinical approach.

Successful use of "cryo-mapping" to avoid phrenic nerve damage during ostial superior vena caval ablation despite nerve proximity.

BACKGROUND: The SVC may require ablation to treat atrial fibrillation. Phrenic nerve proximity identified with pacing maneuvers may preclude ablation. METHODS: We tested a new method using "cryo-mapping" to ablate despite nerve proximity. RESULTS: Of 833 patients undergoing ablation, 110 (12%) had arrhythmogenic substrate at the SVC/RA junction. Of these 110 patients, 66 (60%) had consistent diaphragmatic stimulation when pacing at 10 mA at the prospective site of ablation. Of these 66 patients, 7 had continued arrhythmogenicity despite attempts to modify this substrate. For these 7 patients, we paced 4 cm into the SVC where consistent phrenic nerve stimulation was obtained, and cryoablation at -30 degrees C was performed at sites requiring ablation. In 6 of 7 patients (86%), with continued diaphragmatic capture, cryoablation at -70/-80 degrees C was then performed. In 1 of 7 patients (14%), diaphragmatic stimulation ceased at -30 degrees C, and energy delivery stopped. In the 6 patients in whom cryoablation was completed, the arrhythmogenic substrate was successfully ablated without phrenic nerve injury. CONCLUSIONS: A novel "cryo-mapping" technique during phrenic nerve pacing can be used to successfully ablate arrhythmogenic substrate at the SVC/RA junction despite phrenic nerve proximity.

Successful cryoablation in the noncoronary aortic cusp for a left anteroseptal accessory pathway.

Catheter ablation of anteroseptal accessory pathways may be difficult because of the neighboring conduction tissue that may be damaged with ablation. We report a case of an accessory pathway localized to the anteroseptal region. A pathway potential found in the noncoronary cusp of the aortic valve was successfully targeted for ablation with cryo energy. Observations during tachycardia and pacing maneuvers suggest that the supravalvar aortic musculature may be an integral component of left anteroseptal pathways that can be safely targeted for cryoablation without injury of the atrioventricular conduction system.

Effect of ventricular pacing lead position on tricuspid regurgitation: A randomized prospective trial.

BACKGROUND: Pacing lead-related tricuspid regurgitation (TR), a recognized complication of ventricular pacing lead implantation, may be affected by lead position or diameter. OBJECTIVE: This study sought to determine the effect of ventricular pacing lead position and diameter on pacing lead-related TR. METHODS: A randomized prospective trial compared pacing leads in the right ventricular apex (RVA), right ventricular septum (RVS), or left ventricle via the coronary sinus (LV-CS) in a 1:1:1 fashion. Patients undergoing implantable cardioverter-defibrillator lead implantation in the RVA (RVA-ICD) were enrolled in a comparison group. Patients with preexisting moderate or greater TR were excluded. Prospective clinical evaluation, transthoracic echocardiograms, and device interrogation occurred 24 hours and 12 months after device implantation. RESULTS: Sixty-three patients undergoing pacemaker implantation were randomized to RVA, RVS, or LV-CS pacing, and 48 RVA-ICD patients were enrolled as a comparison group. At 12 months, 6 patients (6.4%) developed moderate or greater TR. Moderate or greater TR was not significantly different between groups if analyzed by intention to treat (RVA 5.9%, RVS 10.0%, LV-CS 6.7%, and RVA-ICD 4.8%) or if analyzed by final lead location (RVA 4.8%, RVS 10.5%, LV-CS 8.3%, and RVA-ICD 5.1%). Ventricular lead-related complications occurred in 3 patients with right ventricular leads (3.2%) and 2 patients with LV-CS leads (11.1%) (P = .184). CONCLUSION: Neither pacing lead position nor diameter appears to affect TR development significantly. LV-CS leads failed to achieve a statistically significant reduction in TR as compared with right ventricular leads.

Influence of preoperative lipid-lowering therapy on postoperative outcome in patients undergoing coronary artery bypass grafting.

Statin therapy has recently been shown to decrease adverse perioperative events in patients undergoing vascular surgery. The potential beneficial effect of lipid-lowering therapy in patients undergoing coronary artery bypass grafting (CABG) is not well known. This was an observational analysis of 4,739 patients who underwent first-time isolated CABG at a single institution from 1995 to 2001. Patients were categorized into 2 groups based on treatment with a lipid-lowering agent within 30 days before surgery. Univariate and multivariate analyses were used to determine the association between lipid-lowering therapy and survival to hospital discharge. Patients in the lipid-lowering group (n = 2,334) tended to be younger (mean age 66 +/- 10 vs 68 +/- 10 years), were more likely to be diabetic (31% vs 28%), and on beta blockers (77% vs 70%) than patients in the nonlipid-lowering group (n = 2,405). In-hospital mortality was significantly lower in the lipid-lowering group than in the nonlipid-lowering therapy group (1.4% vs 2.2%, odds ratio 0.62, 95% confidence interval 0.40 to 0.96, p = 0.03). A multivariable model demonstrated a loss of statistical significance for the effect of lipid-lowering therapy on in-hospital mortality (adjusted odds ratio 0.83, 95% confidence interval 0.5 to 1.37, p = 0.46). In conclusion, preoperative use of lipid-lowering therapy in patients undergoing CABG appears safe and is associated with improved survival to hospital discharge compared with patients not receiving lipid-lowering therapy. However, patient risk factors and other cardioprotective medication use associated with the use of preoperative lipid-lowering therapy appear to explain the association with improved survival.