Huaan Du

Radiofrequency Ablation Versus Antiarrhythmic Medication for Treatment of Ventricular Premature Beats From the Right Ventricular Outflow Tract Prospective Randomized Study

Background—The purpose of this study was to compare the efficacy of radiofrequency catheter ablation (RFCA) versus antiarrhythmic drugs (AADs) for treatment of patients with frequent ventricular premature beats (VPBs) originating from the right ventricular outflow tract (RVOT). Methods and Results—A total of 330 eligible patients were included in the study and were randomly assigned to RFCA or AADs group. The absolute number and the burden of VPBs on 12-lead Holter monitors were measured at baseline and at 1st, 3rd, 6th, and 12th months after randomization. Left ventricular eject fraction was evaluated by transthoracic echocardiogram at baseline and at 3 and 6 months after randomization. During the 1-year follow-up period, VPB recurrence was significantly lower in patients randomized to RFCA group (32 patients, 19.4%) versus AADs group (146 patients, 88.6%; P<0.001, log-rank test). In a Poisson generalized estimating equations (GEE) regression model, RFCA was associated with a greater decrease in the burden of VPBs (incidence rate ratio 0.105; 95% confidence intervals [0.104–0.105]; P<0.001) compared with AADs. In a liner GEE model, the left ventricular eject fraction had a tendency to increase after the treatment in both groups (coefficient, 0.584; 95% confidence intervals [0.467–0.702]; P<0.001). In a Cox proportional model, the QS morphology in lead I was the only predictor of VPB recurrence free for catheter ablation (hazards ratio, 0.154; 95% confidence intervals [0.044–0.543]; P=0.004). Conclusions—Catheter ablation is more efficacious than AADs for preventing VPB recurrence in patients with frequent VPBs originating from the RVOT. QS morphology in lead I was associated with better outcome after ablation.

Predictors of late recurrence of atrial fibrillation after catheter ablation

BACKGROUND To predict the recurrence of atrial fibrillation is important for selecting patients who will be undergoing catheter ablation, several studies respectively evaluated the risk factor of the recurrence of atrial fibrillation post-ablation. OBJECTIVE To investigate the factors predicting the recurrence of atrial fibrillation (AF) after catheter ablation. METHODS 186 patients (55.12 ± 12.06 years, 123 male) including 161 paroxysmal AF and 25 non-paroxysmal AF who underwent catheter ablation were studied. Clinical datum before and during ablation were recorded, and systematic follow-up was conducted after ablation. Univariate and multivariate analyses were carried out to determine the factors predicting late recurrence of AF (LRAF) which means AF recurrence after 3 months. RESULTS There were 47(25.27%) patients who experienced LRAF. Multivariate Logistic regression analysis was carried out to the parameters that P<0.10 in the univariate analysis, which includes overweight/obesity, metabolic syndrome (MetS), AF categories, duration of AF history, left atrial diameter (LAD), diabetes mellitus, ablation strategies, procedural failure and early recurrence of AF after ablation (ERAF). Ultimately, the results demonstrated that overweight/obesity (OR=4.71, 95% CI 1.71-12.98, P=0.003), MetS (OR=4.41, 95% CI 1.56-12.46, P=0.005), procedural failure (OR=58.34, 95% CI 6.83-498.34, P<0.001), and ERAF (OR=3.18, 95% CI 1.07-9.44, P=0.037) were independent predictors of AF recurrence after ablation. CONCLUSION Overweight/obesity, metabolic syndrome, procedural failure and ERAF are independent predictors of late recurrence of atrial fibrillation in this group of patients.

Effect of Nifedipine Versus Telmisartan on Prevention of Atrial Fibrillation Recurrence in Hypertensive Patients

It is controversial whether angiotensin II receptor blockers provide better protection than calcium antagonists against atrial fibrillation (AF) recurrence in hypertensive patients. This study was designed to compare the effect of nifedipine- and telmisartan-based antihypertensive treatments for preventing AF recurrence in hypertensive patients with paroxysmal AF. A total of 149 hypertensive patients with paroxysmal AF were randomized to nifedipine- or telmisartan-based antihypertensive treatment groups. The target blood pressure (BP) was <130/80 mm Hg. Clinic BP, ECG, Holter monitoring, and echocardiography were followed up for 2 years. The primary end point was the incidence of overall and persistent AF recurrence. During follow-up, there was no statistical difference in the rate of patients lowering to target BP between both groups, whereas nifedipine group had slightly better BP control but similar heart rate control at 24 months. The incidence of AF recurrence was similar in both groups (nifedipine versus telmisartan: 58.7% versus 55.4%; P=0.742), and Kaplan–Meier analysis showed no significant difference in the freedom from AF recurrence (log-rank test; P=0.48). However, the rate of developing persistent AF in telmisartan group was lower than that in nifedipine group (5.4% versus 16.0%; P=0.035). Patients in telmisartan group had lower values of left atrial diameter, left atrial volume index, and left ventricular mass index at the end of follow-up. The effects of telmisartan in preventing AF recurrences in hypertensive patients with paroxysmal AF after intensive lowering BP is similar to that of nifedipine, but telmisartan has more potent effects on preventing progression to persistent AF.

Effects of renal sympathetic denervation using saline-irrigated radiofrequency ablation catheter on the activity of the renin-angiotensin system and endothelin-1.

Introduction: Excessive activation of the sympathetic nervous system (SNS) and the renin-angiotensin system (RAS) are crucial and interacted closely in the pathogenesis of chronic cardiovascular diseases. This study investigated the effects of renal denervation (RDN) on the RAS. Materials and methods: Eight Chinese Kunming dogs underwent bilateral RDN utilizing saline-irrigated radiofrequency ablation catheter. Blood pressure (BP) measurements, blood sampling assays and renal angiography were performed at baseline, 30 min, one month and three months after ablation. Results: During three months of follow-up, RDN caused a significant and uniform reduction in plasma level of renin, angiotensin II, and endothelin-1(ET-1), with the reduction of –5.7±6.8 (p=0.049), –19.4±19.3 (p=0.025), and –22.4±21 pg/ml (p=0.02) for plasma renin, –10.6±7.2 (p=0.004), –15.9±8.8 (p=0.001), and –15.2±9.6 pg/ml (p=0.003) for plasma angiotensin II, as well as –3.9±3 (p=0.007), –10.8±5 (p<0.001), and –14.6±6.1 pg/ml (p<0.001) for plasma ET-1. RDN utilizing a saline-irrigated catheter also caused a progressive and substantial BP reduction of –19±22/–8±13, –30±13/–13±14, and –36±20/–16±14 mm Hg (p=0.045, p<0.001, and p<0.002 for systolic BP; p=0.14, p=0.036, and p=0.014 for diastolic BP) without ablation-related complications. Conclusion: RDN substantially decreased BP and also significantly decreased the plasma levels of RAS and ET-1, which might be implicated in the mechanism of BP reduction by RDN.

Efficacy and safety of zotarolimus-eluting stents compared with sirolimus-eluting stents in patients undergoing percutaneous coronary interventions — A meta-analysis of randomized controlled trials

BACKGROUND Whether ZES can further improve angiographic and clinical outcomes compared to SES still remains uncertain. OBJECTIVES The aim of this study was to assess the efficacy and safety of zotarolimus-eluting stents (ZES) compared with sirolimus-eluting stents (SES) in patients undergoing percutaneous coronary interventions (PCI). METHODS Major electronic information sources were explored for randomized controlled trials comparing ZES with SES among patients undergoing PCI during at least 9 months follow-up. The primary efficacy outcomes were target lesion revascularization (TLR), target vessel revascularization (TVR), and major adverse cardiac events (MACE); safety outcomes were stent thrombosis (ST), myocardial infarction (MI), and cardiac death. RESULTS Seven comparative studies were identified (a total of 5983 patients). When compared with ZES at 12-month follow-up, SES significantly reduced risk of MACE (relative risk [RR]: 0.74, 95% confidence interval [CI]: 0.61 to 0.89, p=0.002), and TLR (RR:0.39; 95% CI: 0.29 to 0.52; p<0.00001), without significant differences in terms of TVR (RR:0.68, 95% CI: 0.38 to 1.20; p=0.18), ST (RR:0.71; 95% CI: 0.39 to 1.31; p=0.28), cardiac death (RR:0.83; 95% CI: 0.49-1.42, p=0.50) or MI (RR:1.08; 95%CI: 0.80 to 1.45; p=0.62). CONCLUSIONS At 12-month follow-up, SES are superior to ZES in reducing the incidences of TLR and MACE in patients undergoing PCI, without significant differences in terms of TVR, ST, cardiac death, and MI.

Renin-angiotensin system-related gene polymorphisms are associated with risk of atrial fibrillation

BACKGROUND Renin-angiotensin system (RAS) plays an important role in atrial fibrillation (AF). Recently, many publications have studied the associations between RAS-related gene polymorphisms and AF risk, with inconsistent results. To further evaluate these associations, we carried out a meta-analysis of all the published studies. METHODS Electronic searches were used to identify published studies evaluating RAS-related gene polymorphisms and AF risk before April 2009. We extracted data sets and performed meta-analysis with standardized methods. RESULTS A meta-analysis of 12 publications on association between angiotensin-converting enzyme (ACE insertion/deletion) and AF risk was performed. The pooled relative risk (RR) of allele D versus I was 1.19 (95% CI, 1.07-1.32, P < .01), pooled RR of DD and DI versus II was 1.31(95% CI, 1.09-1.58, P < .01) and 1.06 (95% CI, 0.97-1.16, P = .22) respectively. In subgroup analysis, a stronger association was found in hypertensive population, Western ethnic, lone AF, and patients aged > or = 65 years, with pooled RR of DD versus II was 1.74 (95% CI, 1.39-2.18, P < .01), 1.27 (95% CI, 1.01-1.59, P = .04), 1.53 (95% CI, 1.31-1.78, P < .01) and 1.38 (95% CI, 1.10-1.73, P < .01), respectively. CONCLUSION The results suggested an association between ACE insertion/deletion and AF risk. More large-scale studies are warranted to document the conclusive evidence of the effects of the RAS genes on AF risk.

Preliminary effects of renal denervation with saline irrigated catheter on cardiac systolic function in patients with heart failure: A Prospective, Randomized, Controlled, Pilot Study.

To assess efficacy and safety of renal denervation (RDN) for heart failure (HF).

Selective Proximal Renal Denervation Guided by Autonomic Responses Evoked via High-Frequency Stimulation in a Preclinical Canine Model

Background—Electric stimulation has been proved to be available to monitor the efficacy of renal denervation (RDN). This study was to evaluate the effectiveness of high-frequency stimulation (HFS)–guided proximal RDN. Methods and Results—A total of 13 Chinese Kunming dogs were included and allocated to proximal RDN group (n=8) and control group (n=5). HFS (20 Hz, 8 V, pulse width 2 ms) was performed from proximal to distal renal artery in all dogs. Radiofrequency ablations were delivered in proximal RDN group and only at the proximal positive sites where systolic blood pressure (BP) increased ≥10 mm Hg during HFS. Postablation HFS was performed over the previously stimulated sites. BP, heart rate, and plasma norepinephrine were analyzed. In 8 denervated dogs, preablation HFS caused significant BP increases of 6.0±5.0/3.4±5.5, 16.9±11.7/11.1±8.5, and 17.1±8.4/8.5±5.3 mm Hg during the first, second, and third 20 s of HFS at the proximal positive sites. After ablation, these sites showed a negative response to postablation HFS with increases of BP by 1.3±3.0/1.0±2.5, 0.8±3.9/1.5±3.4, and 1.5±4.5/0.7±3.8 mm Hg. Of note, no radiofrequency applications were delivered at the positive sites of middle renal artery, repeated HFS increased BP only by 3.3±5.3/2.8±4.2, 5.3±6.6/3.8±4.7, and 2.9±4.6/1.3±3.2 mm Hg, failed to reproduce the previous BP increases of 6.2±5.6/5.3±4.4, 15.0±9.3/10.2±6.2, and 14.9±7.7/8.4±4.7 mm Hg. At 3 months, BP and plasma norepinephrine substantially decreased in proximal RDN group. Whereas controls showed minimal BP decreases and had similar plasma norepinephrine concentrations as baseline. Conclusions—Renal afferent nerves can be mapped safely, and HFS-guided targeted proximal RDN can achieve apparent BP reduction and sympathetic inhibition.

Blockade of angiotensin II improves hyperthyroid induced abnormal atrial electrophysiological properties.

BACKGROUND Previous studies reported that RAS inhibitors prevented atrial fibrillation by improving atrial electrical and structural remodeling. However, the effect of RAS inhibitors on the substrates of atrial fibrillation (AF) underlying hyperthyroid is unclear. METHODS Forty rabbits were assigned to four groups: sham group, thyroxine group, benazepril group and irbesartan group (10 per group). The atrial effective refractory period (AERP) was measured. The physiologic rate adaptation and the AF vulnerability were evaluated. The real-time PCR, Western blot or fluorescent immunohistochemistry was performed to detect the expression of AF related Ca+, K+ channel and gap junction. RESULTS No significant difference was found in AERP among the thyroxine group, benazepril group and irbesartan group (75.13±5.41ms vs. 76.63±4.44ms, 79±4.95ms, P=0.28). However, benazepril or irbesartan could reduce AF vulnerability underlying hyperthyroid (75% vs. 37%, 44%, for thyroxine group, benazepril group and irbesartan group, respectively), and significantly improved physiologic rate adaptation of the AERP. Furthermore, both drugs significantly reduced L-Ca(2+) channel related subunits (α1C or α1D) and interstitial fibrosis (17.1±2.2% vs. 12.3±1.8, 11.7±1.2%, P<0.01, for thyroxine group, benazepril group and irbesartan group, respectively), increased lateral/polar connection of Cx43 (1.04±0.16 vs. 1.33±0.29,1.28±0.25, P<0.01, for thyroxine group, benazepril group and irbesartan group, respectively) and improved the abnormal distribution of gap junctions (Cx40, Cx43) underlying hyperthyroid. CONCLUSION Blockade of angiotensin II could improve abnormal atrial electrophysiological properties and further reduce AF vulnerability by extenuating ion channel, gap junction and structural remodeling in experimental thyrotoxic rabbits.

The effect of two different renal denervation strategies on blood pressure in resistant hypertension: Comparison of full-length versus proximal renal artery ablation.

Renal denervation (RDN) is used to manage blood pressure (BP) in patients with resistant hypertension (rHT), but effectiveness is still a concern, and key arterial portion for successful RDN is not clear.