Image-guided left ventricular lead placement in cardiac resynchronization therapy for patients with heart failure: a meta-analysis.

BACKGROUND: Heart failure (HF) is a debilitating condition that affects millions of people worldwide. One means of treating HF is cardiac resynchronization therapy (CRT). Recently, several studies have examined the use of echocardiography (ECHO) in the optimization of left ventricular (LV) lead placement to increase the response to CRT. The objective of this study was to synthesize the available data on the comparative efficacy of image-guided and standard CRT. METHODS: We searched the PubMed, Cochrane, Embase, and ISI Web of Knowledge databases through April 2014 with the following combinations of search terms: left ventricular lead placement, cardiac resynchronization therapy, image-guided, and echocardiography-guided. Studies meeting all of the inclusion criteria and none of the exclusion criteria were eligible for inclusion. The primary outcome measures were CRT response rate, change in LV ejection fraction (LVEF), and change in LV end systolic volume (LVESV). Secondary outcomes included the rates of all-cause mortality and HF-related hospitalization. RESULTS: Our search identified 103 articles, 3 of which were included in the analysis. In total, 270 patients were randomized to the image-guided CRT and 241, to the standard CRT. The pooled estimates showed a significant benefit for image-guided CRT (CRT response: OR, 2.098, 95 % CI, 1.432-3.072; LVEF: difference in means, 3.457, 95 % CI, 1.910-5.005; LVESV: difference in means, -20.36, 95 % CI, -27.819 - -12.902). CONCLUSIONS: Image-guided CRT produced significantly better clinical outcomes than the standard CRT. Additional trials are warranted to validate the use of imaging in the prospective optimization of CRT.

A comparison of steep and shallow needle trajectories in blind axillary vein puncture.

BACKGROUND: Previously developed techniques for pacemaker lead introduction usually require some form of image guidance to facilitate the axillary vein puncture process. The existing blind vein puncture methods have not gained widespread acceptance. We aimed to investigate whether our blind vein puncture approach is effective and safe. METHODS: We compared the patient characteristics and clinical outcomes of 600 consecutive patients who underwent different blind axillary vein puncture procedures. In group I, a steep needle puncture method was used, whereas in group II a shallow needle puncture technique was used. RESULTS: The shallow needle puncture method was associated with a higher success rate than the steep needle puncture method (94% vs 54%, P < 0.00001). The shallow needle puncture method was also associated with a much shorter puncture and lead insertion time (7 ± 2 minutes vs 10 ± 3 minutes, P = 0.02). CONCLUSION: Our shallow needle puncture technique does not require any extra equipment. In addition, this method is effective and safe and may be used as the initial attempt for venous access during pacemaker implantation.

Circulating primary bile acid is correlated with structural remodeling in atrial fibrillation.

BACKGROUND: Circulating primary bile acid was involved in the regulation of cardiac ionic channel currents and ventricular myocyte apoptosis, but it was unknown whether or not it played a role in structural remodeling of AF. This study was aimed to testify the hypothesis that elevated chenodeoxycholic acid (CDCA) concentration correlated with left atrial low voltage area (LVA) and could induce apoptosis of atrial myocytes in AF. METHODS AND RESULTS: Serum concentrations of 12 types of bile acids were determined in patients with paroxysmal (n = 21), persistent AF (n = 20), and type A pre-excitation and paroxysmal supraventricular tachycardia (PSVT) (n = 19) and were correlated with LVA in AF, which was obtained by electroanatomical mapping during ablation. Additionally, the impact of CDCA incubation on apoptosis of mouse atrial myocytes was evaluated. Serum levels of CDCA and cholic acid were significantly higher in AF than in PSVT. CDCA serum concentration was significantly higher in persistent AF than in paroxysmal AF. CDCA serum level was positively correlated with the size (r = 0.78, P < 0.05) and proportion of LVA (r = 0.89, P < 0.05) in AF patients. CDCA (75 µM, 100 µM) promoted atrial myocyte apoptosis in a concentration-dependent manner. CONCLUSIONS: The higher circulating level of CDCA in AF than in PSVT, positive correlation of CDCA with LVA in AF, and incubation dose-dependent increase of mouse atrial myocyte apoptosis indicated that CDCA might play a significant role in the progress of structural remodeling of AF.

Low voltage areas in paroxysmal atrial fibrillation: The prevalence, risk factors and impact on the effectiveness of catheter ablation.

BACKGROUND: The prevalence, risk factors of left atrial low voltage areas (LVA) in paroxysmal atrial fibrillation (PAF) and the impact of LVA on the effectiveness of circumferential pulmonary vein isolation (CPVI) were not fully clarified. METHODS: One hundred fifty patients (mean age 64.7 years, 89 males) with PAF were consecutively enrolled to undergo CPVI. Prior to ablation a contact force sensing ablation catheter was utilized for LVA mapping in sinus rhythm. The patients were graded based on the proportion of LVA (LVA%): non LVA, mild (LVA% ≤ 10%), moderate (LVA% 10%-<20%) and severe (LVA% ≥ 20%), and were followed up for 12 months after initial CPVI. RESULTS: There were 56 in non LVA, 54 in mild LVA, 22 in moderate LVA and 18 in severe LVA. The prevalence of LVA was 62.7% in this PAF cohort, with the most frequent localization at anterior free wall (35.3%), PV antrum (22%) and septum (14.7%). Female gender (OR 3.634, 95% CI 1.704-7.751, P = 0.001) and left atrial surface area (LASA) (OR 1.024, 95% CI 1.000-1.048, P = 0.048) were risk factors of LVA. LVA% exceeding10% was associated with poor effectiveness of CPVI. LVA grade (HR 1.633, 95% CI 1.122-2.378, P = 0.011) was an independent predictor for AF recurrence after initial ablation. CONCLUSIONS: LVA affected >60% of patients with PAF. Female gender and LASA were two risk factors of LVA. LVA grade was an independent predictor for AF recurrence following CPVI.

Timing of early angiography in non-ST elevation acute coronary syndrome.

OBJECTIVES: We aimed to determine the best time period for an early invasive intervention in non-ST elevation acute coronary syndrome (NSTEACS) patients. BACKGROUND: Studies assessing the timing of percutaneous coronary intervention (PCI) in patients with NSTEACS have failed to generate a consensus on when PCI should be performed in such patients. METHODS: Literature searches were conducted for randomized, controlled trials (RCTs) on NSTEACS from 1970 through September 2012. Patients were analyzed who were at moderate to high risk for NSTEACS and who underwent angiography within 96 hours. The major outcomes were the rate of death, recurrent myocardial infarction (re-MI), stroke, and major bleeding. RESULTS: Eight RCTs, which included 5761 patients, were eligible. There were no significant differences in the odds of death or stroke between time points. Conversely, patients undergoing angiography before 2 hours were associated with a higher rate of re-MI, compared with those undergoing angiography more than 2 hours later (odds ratio [OR], 2.15; 95% confidence interval [CI], 1.53-3.02; P<.001; I² = 0%). Major bleeding events decreased only with angiography performed within 12 hours, compared to more than 12 hours (OR, 0.65; 95% CI, 0.44-0.96; P=.03; I² = 0%). Angiography before 2 hours was not associated with a lower rate of major bleeding compared with angiography after 2 hours (OR, 0.61; 95% CI, 0.28-1.30; P=.20; I² = 0%). CONCLUSIONS: Angiography within 12 hours reduces the risk of major bleeding. There is no need to push for angiography within 2 hours.

A novel individualized substrate modification approach for the treatment of long-standing persistent atrial fibrillation: preliminary results.

BACKGROUND: The most effective approach for long-standing persistent atrial fibrillation (LPAF) ablation remained undetermined. Our goal was to explore the heterogeneous left atrial substrate in patients with LPAF and to evaluate the effectiveness of a novel individualized substrate modification (ISM) approach in LPAF ablation. METHODS: One hundred and twenty-four patients with LPAF were randomized to ISM group (n=64) or stepwise ablation (SA) group (n=60). After pulmonary vein isolation, ISM was performed in the ISM group and SA was applied in the SA group. The clinical effectiveness after a single and a repeated procedure was compared. RESULTS: The total procedural time was significantly shorter in ISM than that in SA. In the ISM group, mild left atrial substrate was observed in 17 (27.4%), moderate in 26 (41.9%) and severe in 19 (30.6%) patients after successful cardioversion of the 62 patients. The intention-to-treat analysis showed that sinus rhythm was maintained in 65.5% of patients in the ISM group and in 45.0% of patients in the SA group after a single procedure, P=0.04. Atrial tachycardia (AT) recurred in 5 of 22 in the ISM group and in 20 of 33 in the SA group, P=0.01. After a repeated procedure, 75% of patients in the ISM group and 63.3% of patients in the SA group were free of further recurrence, P=0.16. CONCLUSIONS: Left atrial substrate varied noticeably in patients with LPAF. The ISM approach was superior to SA approach in terms of procedural time, recurrence rate of AT and clinical effectiveness after a single procedure. However, they yielded comparable outcomes after a repeated procedure.

Midterm effects and clinical benefits of left ventricular vs biventricular pacing in heart failure.

BACKGROUND: Although left ventricular pacing (LVP) leads to a greater acute hemodynamic response than does biventricular pacing (BVP), the long-term effects are diverse. We aimed to assess the efficacy of LVP and BVP in patients undergoing cardiac resynchronization therapy and determine which patients would benefit more from LVP or BVP. METHODS: Randomized controlled trials that compared left and biventricular pacing were retrieved from MEDLINE and analyzed for changes in cardiac function and dimensions, cardiac resynchronization therapy response, and electromechanical effects. RESULTS: A total of 811 patients were included from 9 trials. After a mean follow-up, a shorter QRS duration (-40.92 milliseconds; 95% confidence interval [CI], -64.50 to -17.34; P = 0.0007), and improved left ventricular dimensions were observed in the BVP group compared with the LVP group. Moreover, the BVP group had a longer 6-minute hall walk (6MHW) test (37.19 m; 95% CI, 4.72 to 69.67; P = 0.02). CONCLUSION: Our results indicate that BVP results in a better electromechanical effect and leads to a better 6MHW test. For all other test criteria, LVP showed a benefit equal to that of BVP. Thus, there is currently insufficient evidence to advocate for LV-only pacing.